Alix Young Vik

• Helmisdóttir, Lára Hólm; Konradsson, Katarina; Palotie, Ulla; Twetman, Svante & Young, Alix (2025). Er selvudført tandbørstning uden brug af fluorid effektiv som cariesfore­byggende foranstaltning? Den norske tannlegeforenings Tidende. ISSN 0029-2303. 135, p. 30–34. doi: 10.56373/2025-1-7. Full text in Research Archive Show summary

  Professional and self-applied fluorides are included in the WHO list of essential medicines and twice daily toothbrushing with fluoride toothpaste is a cornerstone in the prevention and management of dental caries. For various reasons, there are concerns about adverse health effects from excessive fluoride exposure during pregnancy and infancy, such as dental fluorosis and neurotoxicity. Therefore, the aim of the study was to examine the evidence of efficacy for fluoride-free oral hygiene procedures. We searched three electronic databases for relevant systematic reviews and included six papers of which three had a low or moderate risk of bias. The systematic reviews contained in total 28 primary studies on fluoride toothpaste vs. placebo or no intervention, and all studies were in favor of the fluoride toothpaste for caries prevention. The certainty of evidence for interdental cleaning as an adjunct to toothbrushing was very low. Based on the available systematic reviews, we are very confident that self-performed toothbrushing with fluoride toothpaste is more effective than placebo or no intervention. However, this does not imply a lack of effect and dental professionals need to be aware of fluoride-free alternatives for those individuals that decline the use of fluoride-containing oral hygiene products.

• Sødal, Anne Thea Tveit; Diep, My Tien; Skudutyte-Rysstad, Rasa; Singh, Preet Bano; Young, Alix & Jensen, Janicke Liaaen [Show all 9 contributors for this article] (2024). Oral helse blant 65-åringer i Oslo. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 12(134). doi: 10.56373/2024-12-5. Full text in Research Archive
• Frigaard, Julie Mari; Hynne, Håvard; Randsborg, Karoline; Mellin-Olsen, Tonje; Hofgaard, Anne Kristine & Young, Alix [Show all 10 contributors for this article] (2023). Exploring oral health indicators, oral health-related quality of life and nutritional aspects in 23 medicated patients from a short-term psychiatric ward. Frontiers in Public Health. 11. doi: 10.3389/fpubh.2023.1083256. Full text in Research Archive Show summary

  Background Patients suffering from psychiatric disorders face many difficulties due to their condition, medications and lifestyle. Oral health and nutrition may be affected, further complicating their lives. Our aim was to provide in-depth information on oral health and nutritional factors in a small group of patients in short-term psychiatric ward. Methods Twenty-three patients (mean age 36, average medications five) were recruited during short-term hospitalization in a psychiatric ward. Inclusion criteria: anxiety, psychosis and/or depression, and use of at least one antidepressant or anxiolytic/antipsychotic drug with xerostomia as a known side effect. Subjective oral dryness was evaluated using the Shortened Xerostomia Inventory (SXI). Oral examination included Clinical Oral Dryness Score (CODS), secretion of unstimulated (UWS) and stimulated whole saliva (SWS), and evaluation of dental, gingival, and periodontal status. Self-reported complaints of oral disorders were recorded. The Oral Health Impact Profile-14 (OHIP-14) was used to explore oral health-related quality of life. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment Short Form (PG-SGA-SF), and diet quality was assessed using the Mediterranean diet score (KIDMED). Results Compared to healthy controls, the patients had significantly higher SXI scores and CODS, and SWS secretion was lower. Complaints of dysgeusia and halitosis were significantly more frequent among patients. Gingivitis was more common in patients. OHIP-14 scores were much higher in the patients, and they reported significantly poorer oral and general health. Most patients lacked a regular meal pattern. Very low diet quality was observed in five patients, while improvements were needed in twelve. “ Dry mouth ” and “ No appetite, just did not feel like eating ” were the most common symptoms preventing patients from eating enough. The PG-SGA-SF symptoms component score showed a strong negative correlation with self-reported oral health, and a strong positive correlation with OHIP-14. Conclusion This relatively small group of patients in short-term psychiatric ward had both reduced oral health and poor oral health-related quality of life. Furthermore, their nutritional intake was affected by their oral health problems. Although larger groups need to be studied, these findings indicate that oral health and nutrition should be evaluated and adjusted in these patients to improve their overall care.

• Diep, My Tien; Skudutyte-Rysstad, Rasa; Sødal, Anne Thea Tveit; Young, Alix & Hove, Lene Hystad (2023). Caries experience and risk indicators of having decayed teeth among 65-year-olds in Oslo, Norway: a cross-sectional study. BMC Oral Health. 23(1). doi: 10.1186/s12903-023-03432-x. Full text in Research Archive Show summary

  Background Meeting the oral health needs of the increasing population of older adults presents a major challenge in dental care. Knowledge about the oral health status in the young-elderly age group is essential for the planning of future oral health education and prevention programs. The aims of the present study were therefore to investigate the caries experience among 65-year-olds in Oslo, Norway, and to explore associations between having decayed teeth and sociodemographic, behavioural, and biological factors. Methods A random sample of 65‑year‑olds in Oslo answered a questionnaire and underwent clinical and radiographic examinations (n = 457, 52% men and 48% women) at the Research Clinic, Faculty of Dentistry, University of Oslo, between February and December 2019. Primary- and secondary coronal and root caries lesions, root remnants, and missing and restored teeth were recorded. Decayed teeth (DT) were defined as teeth with coronal- and root caries lesions that had progressed into dentine and root remnants, and the DMFT/S scores were calculated. Results The mean number of teeth was 25 (SD: 4) and the mean DMFT was 19.4 (SD: 4.7). Thirty seven percent of the individuals had at least one decayed tooth (DT > 0), and the mean number of filled teeth (FT) was 16.1 (SD: 5.4). Multivariable logistic regression analysis showed that male gender (OR: 1.8, 95% CI: 1.2–2.8), basic level of education (OR: 1.9, 95% CI: 1.2–2.9), irregular dental attendance (OR: 2.2, 95% CI: 1.0-4.8), and hyposalivation (OR: 2.1, 95% CI: 1.0-4.4) were significant risk indicators for having decayed teeth (DT > 0) (p < 0.05). Conclusions In conclusion, 65-year-olds in Oslo had a low average number of decayed and missing teeth, and a high number of restored teeth. Irregular dental attendance and hyposalivation were the strongest risk indicators for having decayed teeth. Based on the present results, it will be important to ensure access to regular dental care and to increase the emphasis on caries preventive measures for individuals with hyposalivation in this age group.

• Young, Alix; Skudutyte-Rysstad, Rasa; Torgersen, Gerald R. & Giertsen, Elin (2022). Teaching radiographic caries detection and treatment planning: A seminar using an audience response system. Caries Research. ISSN 0008-6568. 56(3), p. 226–233. doi: 10.1159/000526109. Full text in Research Archive Show summary

  This study presents a seminar model for teaching radiographic caries detection and treatment planning at the Faculty of Dentistry, University of Oslo. The seminar is based partly on an audience response system (ARS) and uses patient cases to focus on caries risk assessment and treatment planning. This paper describes the seminar design, implementation, learning outcomes, and observational study of variability in caries registrations and students’ attitudes to use of ARS. Dental and dental hygiene students participate in two seminar modules. Module 1 aims to develop and increase individual student skills in radiographic caries lesion detection, scoring, and differential diagnosis. Students perform trial registrations on bitewings using an ARS with anonymous live polling, and scorings are discussed in plenum. Students then perform individual registrations on 12 bitewing pairs. Using digital scoring, students detect and grade caries lesions on all approximal and occlusal tooth surfaces. After the session, students use the ARS to repeat scorings on selected tooth surfaces, and results are again discussed in plenum. Module 2 involves group exercises on 4 patient cases that are later presented with plenary discussions. In total, 1,624 caries registrations performed by 150 students attending the seminar between 2016 and 2018 were assessed for variability between students. As expected, variations in caries registrations were observed between students, mostly related to restored surfaces or tooth surfaces that were otherwise difficult to register. In 2022, 63 dental and dental hygiene students attending the seminar answered a questionnaire about use of ARS. The responses were scored using a five-point Likert scale. Overall, no significant difference in satisfaction with the ARS-based module was observed between dental and dental hygiene students (χ&lt;sup&gt;2&lt;/sup&gt; test, &lt;i&gt;p&lt;/i&gt; &amp;#x3e; 0.05). The majority of the students were positive toward the use of ARS (94%), but some disagreed on the role of ARS in usefulness for understanding the seminar content (3.2%), and in increasing their confidence in radiographic registration of caries (3.2%). The ARS-based module provides a positive learning environment that ensures student anonymity, interactivity, and engagement, and combined with the other seminar module gives students basic skills in caries detection and treatment planning.

• Diep, My Tien; Jensen, Janicke Liaaen; Skudutyte-Rysstad, Rasa; Young, Alix; Sødal, Anne Thea Tveit & Petrovski, Beata [Show all 7 contributors for this article] (2021). Xerostomia and hyposalivation among a 65-yr-old population living in Oslo, Norway. European Journal of Oral Sciences. ISSN 0909-8836. 129(1), p. 1–11. doi: 10.1111/eos.12757. Full text in Research Archive Show summary

  This study aimed to describe the prevalence and associated factors for xerostomia and hyposalivation in a young-elderly population. A random sample of 460 65-yr-old people living in Oslo, Norway, answered a questionnaire and underwent a clinical examination (237 men and 223 women; response rate 58%). Ten percent of respondents reported xerostomia. The median Summated Xerostomia Index was 6 (interquartile range [IQR]: 5–7) and the median Clinical Oral Dryness Score was 2 (IQR: 1–3). The median unstimulated whole saliva (UWS) secretion rate was 0.34 (IQR: 0.20–0.53) mL min–1 and the median stimulated whole saliva (SWS) secretion rate was 1.74 (IQR: 1.24–2.38) mL min–1. In 8% of the study participants the UWS secretion rate was ≤0.1 mL min–1 and in 4% the SWS secretion rate was ≤0.7 mL min–1. Three percent of the study participants had both xerostomia and hyposalivation with respect to UWS. Xerostomia was significantly associated with medication use, having rheumatic disease, and having received radiation therapy to the head/neck region. Hyposalivation with respect to UWS and SWS was significantly associated with medication use and type II diabetes. Even though xerostomia and hyposalivation were not prevalent conditions in this population, clinicians should be especially aware of the salivary conditions in patients taking four or more medications, patients diagnosed with type II diabetes, and those who have undergone radiation therapy to the head/neck region.

• Young, Alix; Hove, Lene Hystad; Stevning, Karen; Løvik, Sara-Emilie & Hjortsjö, Carl (2021). Kan tannpasta gjøre tennene mer sårbare? En in vitro pilotstudie om endring i fukting av emalje uttrykt ved kontaktvinkelmålinger. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 131(9), p. 796–801. Full text in Research Archive
• Westgaard, Kristine Løken; Hynne, Håvard; Amdal, Cecilie Delphin; Young, Alix; Singh, Preet Bano & Chen, Xiangjun [Show all 12 contributors for this article] (2021). Oral and ocular late effects in head and neck cancer patients treated with radiotherapy. Scientific Reports. 11:4026, p. 1–11. doi: 10.1038/s41598-021-83635-w. Full text in Research Archive Show summary

  A broader understanding of oral and ocular late effects in head and neck cancer (HNC) patients who underwent intensity-modulated radiotherapy (IMRT) may provide valuable information in follow-up and improve quality of life. Twenty-nine HNC patients treated at least 6 months earlier and 30 age-matched controls were recruited. After completing several questionnaires: Oral Health Impact Profile-14 (OHIP-14), Shortened Xerostomia Inventory (SXI), Ocular Surface Disease Index (OSDI) and McMonnies Dry Eye questionnaire (MDEQ), participants underwent oral and ocular examinations. Oral examination included clinical oral dryness score (CODS) and secretion rates of unstimulated and stimulated saliva (UWS, SWS). Ocular examination included tear film break-up time, Schirmer test and ocular surface staining. The patients had more problems related to dry mouth than controls based on CODS and SXI, and more complaints of dry eye disease based on OSDI and MDEQ. UWS and SWS rates and oral health related quality of life were significantly lower in the patient group. Subjective oral dryness (SXI) correlated significantly with subjective ocular dryness (OSDI and MDEQ). Our study demonstrates that HNC patients treated with IMRT experience late effects in terms of xerostomia and ocular dryness underlining the importance of interdisciplinary approach in the evaluation and follow-up of HNC patients.

• Aqrawi, Lara A.; Chen, Xiangjun; Hynne, Håvard; Amdal, Cecilie Delphin; Reppe, Sjur & Aass, Hans Christian Dalsbotten [Show all 14 contributors for this article] (2020). Cytokines Explored in Saliva and Tears from Radiated Cancer Patients Correlate with Clinical Manifestations, Influencing Important Immunoregulatory Cellular Pathways. Cells. 9(9). doi: 10.3390/cells9092050. Full text in Research Archive Show summary

  Although radiotherapy is a common form of treatment for head and neck cancer, it may lead to tissue damage in the salivary and lacrimal glands, possibly affecting cytokine expression in the gland fluid of treated individuals. Cytokine profiles in saliva and tear fluid of 29 radiated head and neck cancer patients and 20 controls were screened using a multiplex assay. Correlations between cytokine expression and clinical oral and ocular manifestations were examined, and cellular pathways influenced by these cytokines were assessed using the Functional Enrichment Analysis Tool. Significantly elevated cytokines identified in patient saliva were CCL21, IL-4, CX3CL1, CCL2, CXCL1 and CCL15. Many of these cytokines correlated positively with objective signs of oral dryness, and reduced saliva production in the patients. Although CCL21 and IL-4 levels were significantly lower in patient tear fluid, they correlated with subjective ocular symptoms. These increased salivary cytokines affected pro-inflammatory and apoptotic cellular pathways, including T cell signalling, several interleukin signalling pathways, TNF and TGF-β receptor signalling, and the apoptotic p53 pathway. In conclusion, the upregulated salivary cytokines identified suggest an interplay between innate and adaptive immunity, affecting immunoregulatory cellular pathways. Whether this is due to late effects of radiotherapy or tissue repair remains to be investigated.

• Tashbayev, Behzod; Garen, Torhild Oddveig; Palm, Øyvind; Chen, Xiangjun; Herlofson, Bente Brokstad & Vik, Alix Rosslyn Young [Show all 13 contributors for this article] (2020). Patients with non-Sjögren's sicca report poorer general and oral health-related quality of life than patients with Sjögren's syndrome: a cross-sectional study. Scientific Reports. 10(2063). doi: 10.1038/s41598-020-59078-0. Full text in Research Archive Show summary

  Understanding the impact of the disease on quality of life is crucial in patient management. In this cross-sectional study, general and oral health-related quality of life questionnaires, and thorough examinations of oral and ocular dryness were performed in age- and sex-matched patients with primary Sjögren’s syndrome (pSS group), non-Sjögren’s syndrome sicca (non-SS group) and healthy controls. General and oral health-related quality of life were investigated with the 36-Item Short Form Health Survey and the 14-Item Oral Health Impact Profle questionnaires, respectively. Subjective symptoms of xerostomia and ocular dryness were recorded using the Summated Xerostomia Inventory and Ocular Surface Disease Index, respectively. Clinical examinations included evaluation of clinical oral dryness scores, candida counts, unstimulated and stimulated saliva secretory rates, tear osmolarity, tear flm break-up time, Schirmer I test and ocular surface staining. Both patient groups had pronounced signs and symptoms of xerostomia and ocular dryness. Even though the non-SS patients had less severe clinical signs than the pSS patients, they demonstrated much poorer general and oral health-related quality of life. In conclusion, non-SS patients require more attention in order to improve their quality of life.

• Rusthen, Shermin; Kristoffersen, Anne Karin; Young, Alix; Galtung, Hilde; Petrovski, Beata & Palm, Øyvind [Show all 8 contributors for this article] (2019). Dysbiotic salivary microbiota in dry mouth and primary Sjögren’s syndrome patients. PLOS ONE. 14(6), p. 1–15. doi: 10.1371/journal.pone.0218319. Full text in Research Archive Show summary

  Objectives Primary Sjögren’s syndrome (pSS) is an autoimmune disease characterized by reduced lacrimal and salivary secretion. Sicca symptoms together with fatigue and musculoskeletal pain can significantly reduce the patients’ quality of life. Furthermore, low salivary secretion may disrupt the oral microbial homeostasis. The aim of this study was to compare the salivary microbiota from pSS patients with patients with sicca symptoms not fulfilling the classification criteria for pSS (non-SS), and with healthy controls without sicca complaints. Methods Pellets from centrifuged chewing-stimulated whole saliva from pSS patients (n = 15), non-SS sicca patients (n = 15) and healthy controls (n = 15) were prepared. DNA was extracted and analyzed by 16S rRNA gene sequencing. The acquired sequencing data were performed using the human oral microbiome database (HOMD). Results We detected 42, 45, and 34 bacterial genera in saliva samples from pSS patients, non-SS sicca patients, and healthy controls, respectively. The most abundant genera in all samples were Prevotella, Veillonella, Streptococcus, and Haemophilus. At species level Streptococcus intermedius, Prevotella intermedia, Fusobacterium nucleatum subsp. vincentii, Porphyromonas endodontalis, Prevotella nancensis, Tannerella spp., and Treponema spp. were detected in the samples from pSS and non-SS only, while Porphyromonas pasteri was mostly found among the healthy controls. Conclusion Our study indicated dysbiosis in the salivary microbiota from pSS and non-SS patients compared to healthy controls. Additionally, the results showed that the salivary microbiome in the pSS group differed significantly from the non-SS group.

• Singh, Preet Bano; Young, Alix; Homayouni, Amin; Hove, Lene Hystad; Petrovski, Beata & Herlofson, Bente Brokstad [Show all 9 contributors for this article] (2019). Distorted Taste and Impaired Oral Health May Affect Nutritional Status in Patients with Sicca Complaints. Nutrients. 11(2). doi: 10.3390/nu11020264. Full text in Research Archive Show summary

  Senses of smell and taste, saliva flow, and dental status are considered as important factors for the maintenance of a good nutritional status. Salivary secretory rates, chemosensory function, burning mouth sensation, halitosis and dental status were investigated in 58 patients with primary Sjögren’s syndrome (pSS), 22 non-Sjögren’s syndrome sicca (non-SS) patients, and 57 age-matched healthy controls. A significantly greater proportion of patients with pSS and non-SS had ageusia, dysgeusia, burning mouth sensation, and halitosis compared to controls. Patients with pSS had significantly lower olfactory and gustatory scores, and significantly higher caries experience compared to controls. Patients with pSS and non-SS patients had significantly lower unstimulated and stimulated whole saliva secretory rates compared to controls. The findings indicated that several different aspects of oral health were compromised in both, patients with pSS and non-SS, and this may affect their food intake and, hence, their nutritional status. Although non-SS patients do not fulfill Sjögren’s syndrome classification criteria, they have similar or, in some cases, even worse oral complaints than the patients with pSS. Further studies are needed to investigate food preferences, dietary intake, and nutritional status in these two patient groups in relation to their health condition.

• Schlueter, Nadine; Amaechi, Bennett T.; Bartlett, David; Buzalaf, Marília A.; Carvalho, Thiago Saads & Ganss, Carolina [Show all 15 contributors for this article] (2019). Terminology of erosive tooth wear: Consensus report of a workshop organized by the ORCA and the cariology research Group of the IADR. Caries Research. ISSN 0008-6568. p. 1–5. doi: 10.1159/000503308. Full text in Research Archive Show summary

  Our understanding of erosive tooth wear and its contributing factors has evolved considerably over the last decades. New terms have been continuously introduced, which frequently describe the same aspects of this condition, whereas other terms are being used inappropriately. This has led to unnecessary confusion and miscommunication between patients, professionals, and researchers. A group of 15 experts, selected by the European Organization for Caries Research (ORCA) and the Cariology Research Group of the International Association for Dental Research (IADR), participated in a 2-day workshop to define the most commonly used terms in erosive tooth wear. A modified Delphi method was utilized to reach consensus. At least 80% agreement was achieved for all terms discussed and their definitions related to clinical conditions and processes, basic concepts, diagnosis, risk, and prevention and management of erosive tooth wear. Use of the terms agreed on will provide a better understanding of erosive tooth wear and intends to enable improved communication on this topic.

• Singh, Preet Bano; Young, Alix; Lind, Synnøve; Leegard, Marie Cathinka; Capuozzo, Alessandra & Parma, Valentina (2018). Smelling anxiety chemosignals impairs clinical performance of dental students. Chemical Senses. ISSN 0379-864X. 43(6), p. 411–417. doi: 10.1093/chemse/bjy028. Full text in Research Archive
• Nesvold, Marianne Bakke; Jensen, Janicke Liaaen; Hove, Lene Hystad; Singh, Preet Bano; Young, Alix & Palm, Øyvind [Show all 9 contributors for this article] (2018). Dietary intake, body composition and oral health parameters among female patients with primary Sjögren’s syndrome. Nutrients. 10:866(7), p. 1–12. doi: 10.3390/nu10070866. Full text in Research Archive Show summary

  There is limited knowledge about dietary intake and body composition among patients with primary Sjögren’s syndrome. We assessed dietary intakes with 24-h recalls and body composition with anthropometry and bioelectrical impedance in 20 female patients. Various scoring tools were used to assess oral health. The patients had a lower energy percentage (E%) from carbohydrates (p = 0.02) and a higher E% from fat (p = 0.01) compared to a reference group. The lower intake of carbohydrates was due to a lower bread intake (p = 0.04), while the higher intake of fat was due to a higher intake of butter, margarine, and oil (p = 0.01). The patients ate more than twice (p = 0.02) as much fish as the reference group. The compliance to recommended intakes of macro- and micronutrients was good. Forty-percent of the patients were overweight/obese. Increased intake of beverages was observed in patients with severe xerostomia and/or low oral health-related quality of life, whereas reduced fat intake was found in hyposmic patients. In conclusion, the dietary intake among the patients was not much different from the reference group and complied with recommendations. Most oral health parameters were not associated with nutrient intakes. Specific dietary guidelines are probably not needed to ensure adequate nutrition among such patients.

• Pistone, Sara; Goycoolea, Francisco M.; Young, Alix; Smistad, Gro & Hiorth, Marianne (2017). Formulation of polysaccharide-based nanoparticles for local administration into the oral cavity. European Journal of Pharmaceutical Sciences. ISSN 0928-0987. 96, p. 381–389. doi: 10.1016/j.ejps.2016.10.012. Full text in Research Archive Show summary

  The efficacy of treatments for oral ailments is often challenged by a low residence time of the conventional pharmaceutical formulations in the oral cavity. The residence time in the oral cavity could be improved by using bioadhesive formulations, such as preparations based on polysaccharides. This study describes the formulation and the evaluation of polysaccharide-based nanosystems as drug delivery systems addressed to the oral cavity. Nanoparticles based on chitosan, alginate or pectin were prepared through self-assembly by ionotropic gelation using oppositely charged crosslinkers (tripolyphosphate or zinc). Characteristics of nanoparticles at increasing crosslinker concentration provided the basis for selecting the most suitable formulations. The nanoparticles were tested for cytotoxicity against buccal cells (TR146) and for stability in a medium simulating pH, ionic strength, electrolyte composition and concentration of saliva. Alginate nanoparticles were the most stable in the salivary environment, while chitosan nanoparticles were the most cytocompatible. Alginate nanoparticles and pectin nanoparticles revealed possible cytotoxicity due to the presence of zinc. This knowledge is important in the early design of polymer-based nanoparticles for oral usage and for potential improving of the biocompatibility of the investigated nanoparticles with the oral environment.

• Tashbayev, Behzod; Rusthen, Shermin; Young, Alix; Herlofson, Bente Brokstad; Hove, Lene Hystad & Singh, Preet Bano [Show all 13 contributors for this article] (2017). Interdisciplinary, comprehensive oral and ocular evaluation of patients with primary Sjögren's syndrome. Scientific Reports. 7:10761, p. 1–9. doi: 10.1038/s41598-017-10809-w. Full text in Research Archive Show summary

  A comprehensive evaluation of oral and ocular symptoms and findings in primary Sjögren’s syndrome (pSS) patients may provide valuable information for management. Medical history was obtained from female pSS patients, and sex- and age-matched non-SS patients with sicca symptoms (non-SS sicca controls) as well as healthy subjects without sicca complaints (healthy controls). Oral (Summated Xerostomia Inventory, SXI) and ocular (McMonnies Dry Eye questionnaire, MDEIS, and Ocular Surface Disease Index, OSDI) subjective complaints were recorded. Objective findings including clinical oral dryness scores (CODS), unstimulated and stimulated saliva secretion rates (UWS/SWS), Schirmer I test, tear osmolarity, tear film break-up time (TFBUT), and ocular surface staining (OSS) were determined. The pSS and non-SS sicca controls were extensively troubled by subjective dryness, while the pSS group had higher CODS, significantly lower saliva and tear secretion, shorter TFBUT and higher OSS than both control groups. Furthermore, candida counts were significantly higher in the pSS patients. In the pSS group, subjective oral dryness significantly correlated with ocular dryness (MDEIS: r = 0.5, OSDI: r = 0.413) and SWS was significantly correlated with Schirmer I (r = 0.419). The findings imply that interdisciplinary subjective and objective evaluation of patients with xerostomia and xerophthalmia not only have implications for patient care, but also may guide clinicians in differentiating between pSS and non-SS sicca patients.

• Rusthen, Shermin; Young, Alix; Herlofson, Bente Brokstad; Aqrawi, Lara Adnan; Rykke, Morten & Hove, Lene Hystad [Show all 9 contributors for this article] (2017). Oral disorders and oral health-related quality of life in patients with primary Sjögren’s Syndrome. European Journal of Oral Sciences. ISSN 0909-8836. 125(4), p. 265–271. doi: 10.1111/eos.12358. Full text in Research Archive
• Aqrawi, Lara Adnan; Galtung, Hilde; Vestad, Beate; Øvstebø, Reidun; Thiede, Bernd & Rusthen, Shermin [Show all 13 contributors for this article] (2017). Identification of potential saliva and tear biomarkers in primary Sjögren’s syndrome, utilising the extraction of extracellular vesicles and proteomics analysis. Arthritis Research & Therapy. ISSN 1478-6354. 19(1). doi: 10.1186/s13075-017-1228-x. Full text in Research Archive Show summary

  Background There is a long-lasting need for non-invasive, more accurate diagnostic techniques when evaluating primary Sjögren’s syndrome (pSS) patients. Incorporation of additional diagnostics involving screening for disease-specific biomarkers in biological fluid is a promising concept that requires further investigation. In the current study we aimed to explore novel disease biomarkers in saliva and tears from pSS patients. Methods Liquid chromatography-mass spectrometry (LC-MS) was performed on stimulated whole saliva and tears from 27 pSS patients and 32 healthy controls, and salivary and tear proteomic biomarker profiles were generated. LC-MS was also combined with size exclusion chromatography to isolate extracellular vesicles (EVs) from both fluids. Nanoparticle tracking analysis was conducted on joint fractions from the saliva and tears to determine size distribution and concentration of EVs. Further EV characterisation was performed by immunoaffinity capture of CD9-positive EVs using magnetic beads, detected by flow cytometry. The LC-MS data were analysed for quantitative differences between patient and control groups using Scaffold, and the proteins were further analysed using the Database for Annotation, Visualization and Integrated Discovery (DAVID), for gene ontology overrepresentation, and the Search Tool for the Retrieval of Interacting Genes/Proteins for protein-protein interaction network analysis. Results Upregulation of proteins involved in innate immunity (LCN2), cell signalling (CALM) and wound repair (GRN and CALML5) were detected in saliva in pSS. Saliva EVs also displayed biomarkers critical for activation of the innate immune system (SIRPA and LSP1) and adipocyte differentiation (APMAP). Tear analysis indicated overexpression of proteins involved in TNF-α signalling (CPNE1) and B cell survival (PRDX3). Moreover, neutrophil gelatinase-associated lipocalin was upregulated in saliva and tears in pSS. Consistently, DAVID analysis demonstrated pathways of the adaptive immune response in saliva, of cellular component assembly for saliva EVs, and of metabolism and protein folding in tears in pSS patients. Conclusions LC-MS of saliva and tears from pSS patients, solely and in combination with size-exclusion chromatography allowed screening for possible novel biomarkers encompassing both salivary and lacrimal disease target organs. This approach could provide additional diagnostic accuracy in pSS, and could possibly also be applied for staging and monitoring the disease.

• Tonetti, Maurizio S.; Bottenberg, Peter; Conrads, Georg; Eickholz, Peter; Heasman, Peter & Huysmans, Marie-Charlotte [Show all 21 contributors for this article] (2017). Dental caries and periodontal diseases in the ageing population: call to action to protect and enhance oral health and well-being as an essential component of healthy ageing - Consensus report of group 4 of the joint EFP/ORCA workshop on the boundaries between caries and periodontal diseases. Journal of Clinical Periodontology. ISSN 0303-6979. 44, p. S135–S144. doi: 10.1111/jcpe.12681. Full text in Research Archive Show summary

  Background: Over the last two decades, progress in prevention and treatment of caries and periodontal diseases has been translated to better oral health and improved tooth retention in the adult population. The ageing population and the increasing expectations of good oral health-related quality of life in older age pose formidable challenges to clinical care and healthcare systems. Aims: The objective of this workshop was to critically review scientific evidence and develop specific recommendations to: (i) prevent tooth loss and retain oral function through prevention and treatment of caries and periodontal diseases later in life and (ii) increase awareness of the health benefits of oral health as an essential component of healthy ageing. Methods: Discussions were initiated by three systematic reviews covering aspects of epidemiology of caries and periodontal diseases in elders, the impact of senescence on caries and periodontal diseases and the effectiveness of interventions. Recommendations were developed based on evidence from the systematic reviews and expert opinion. Results: Key messages included: (i) the ageing population, trends in risk factors and improved tooth retention point towards an expected increase in the total burden of disease posed by caries and periodontal diseases in the older population; (ii) specific surveillance is required to monitor changes in oral health in the older population; (iii) senescence impacts oral health including periodontitis and possibly caries susceptibility; (iv) evidence indicates that caries and periodontal diseases can be prevented and treated also in older adults; (v) oral health and functional tooth retention later in life provides benefits both in terms of oral and general quality of life and in terms of preventing physical decline and dependency by fostering a healthy diet; (vi) oral healthcare professionals and individuals should not base decisions impacting tooth retention on chronological age but on level of dependency, life expectancy, frailty, comfort and quality of life; and (vii) health policy should remove barriers to oral health care for vulnerable elders. Conclusions: Consensus was reached on specific actionable priorities for public health officials, oral healthcare professionals, educators and workforce planners, caregivers and relatives as well as for the public and ageing patients. Some priorities have major implications for policymakers as health systems need to adapt to the challenge by systemwide changes to enable (promote) tooth retention later in life and management of deteriorating oral health in increasingly dependent elders. This article has been accepted and published in the Journal of Clinical Periodontology. © 2017 Wiley

• Vanberg, Karin Elisabeth; Husby, Iselin Elise; Stykket, Liv; Young, Alix & Willumsen, Tiril (2016). Tannhelse blant et utvalg injiserende heroinmisbrukere i Oslo :. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 126(7), p. 528–534. Full text in Research Archive
• Soares, Lèo; Jonski, Grazyna; Tinoco, Eduardo Muniz Barretto & Young, Alix (2015). Short-term effect of strontium- and zinc-containing toothpastes and mouthrinses on volatile sulphur compounds in morning breath: A randomized, double-blind, cross-over clinical study. European Journal of Oral Sciences. ISSN 0909-8836. 123(2), p. 72–79. doi: 10.1111/eos.12169. Full text in Research Archive
• Hjortsjø, Carl; Young, Alix; Kiesow, Andreas; Cismak, Andreas; Berthold, Lutz & Petzold, Matthias (2015). A Descriptive in vitro Electron Microscopic Study of Acidic Fluoride-Treated Enamel: Potential Anti-Erosion Effects. Caries Research. ISSN 0008-6568. 49(6), p. 618–625. doi: 10.1159/000441195. Full text in Research Archive
• Hjortsjø, Carl; Jonski, Grazyna; Young, Alix & Saxegaard, Erik (2014). Etching effect of acidic fluorides on human tooth enamel in vitro. Archives of Oral Biology. ISSN 0003-9969. 59(12), p. 1328–1333. doi: 10.1016/j.archoralbio.2014.08.007. Full text in Research Archive
• Huysmans, Marie-Charlotte; Young, Alix & Ganss, Carolina (2014). The role of fluoride in erosion therapy. Monographs in Oral Science. ISSN 0077-0892. 25, p. 230–243. doi: 10.1159/000360555. Full text in Research Archive
• Mulic, Aida; Vidnes-Kopperud, Simen; Skaare, Anne B; Tveit, Anne Bjørg & Young, Alix (2012). Opinions on Dental Erosive Lesions, Knowledge of Diagnosis, and Treatment Strategies among Norwegian Dentists: A Questionnaire Survey. International Journal of Dentistry. ISSN 1687-8728. doi: 10.1155/2012/716396. Full text in Research Archive
• Hjortsjø, Carl; Mjølnerød, Jol Anders; Skaare, Anders; Jonski, Grazyna; Young, Alix & Ekfeldt, Anders (2012). A replica technique for studying the effect of fluoride solutions on enamel erosion. Swedish Dental Journal. ISSN 0347-9994. 36 , p. 169–178. Full text in Research Archive
• Young, Alix & Jonski, Grazyna (2011). Effect of a single brushing with two Zn-containing toothpastes on VSC in morning breath: a 12 h, randomized, double-blind, cross-over clinical study. Journal of Breath Research. ISSN 1752-7155. 5(4). doi: 10.1088/1752-7155/5/4/046012. Full text in Research Archive
• Rölla, Gunnar; Young, Alix & Øgaard, Bjørn (2011). Om fluoriders virkningsmekanismer :. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 121(6), p. 366–370. Full text in Research Archive
• Young, Alix & Tenuta, Livia M.A. (2011). Initial erosion models. Caries Research. ISSN 0008-6568. 45, p. 33–42. doi: 10.1159/000325943. Full text in Research Archive Show summary

  Initial dental erosion - the very first tooth surface changes caused by short-term acidic exposures before any tissue loss is observed - has been studied using in vitro and in situ/in vivo protocols. This paper describes the events that should be considered when modeling initial erosion, the available protocols and their strengths and limitations. In vitro initial erosion models can provide relevant information about the erosive outcome. However, the published studies vary considerably regarding the erosive parameters used, and few of these studies have been validated. On the other hand, relevant in situ/in vivo studies are available that have studied the effect of salivary pellicle and preventive treatments on initial erosion, as well as the changes in salivary pH following exposure to acid solutions. Guidelines for good methodology in modeling initial erosion are proposed.

• Ganss, Carolina; Young, Alix & Lussi, Adrian (2011). Tooth wear and erosion: Methodological issues in epidemiological and public health research and the future research agenda. Community Dental Health. ISSN 0265-539X. 28(3), p. 191–195. doi: 10.1922/CDH_2796Ganss05. Full text in Research Archive Show summary

  Background: This paper addresses methodological issues in the field of tooth wear and erosion research including the epidemiological indices, and identifies future work that is needed to improve knowledge about tooth wear and erosion. Methods: The paper is result of the work done at the meetings of the Special Interest Group “Tooth Surface Loss and Erosion” at the 2008, 2009 and 2010 conferences of the European Association for Dental Public Health, and the Workshop “Current Erosion indices- flawed or valid” which took place in Basel in 2007. Results: Although there is consensus about the definition and the diagnostic criteria of various forms of tooth wear, gaps in research strategies have been identified. A basic problem is that fundamental concepts of wear and erosion as an oral health problem, have not yet been sufficiently defined. To a certain extent, tooth wear is a physiological condition, and there is no consensus as to whether it can be regarded as a disease. Furthermore, the multitude of indices and flaws in existing indices, make published data difficult to interpret. Conclusion: Topics for the research agenda are: the initiation of a consensus process towards an internationally accepted index, and the initiation of data collection on the prevalence of various forms of wear on a population-based level. There should be an emphasis on promoting communication between basic and clinical sciences, and the area of Public Health Dentistry. Furthermore, the question of whether tooth wear is a public health problem remains open for debate.

• Hjortsjø, Carl; Jonski, Grazyna; Young, Alix & Saxegaard, Erik (2010). Effect of acidic fluoride treatments on early enamel erosion lesions-A comparison of calcium and profilometric analyses. Archives of Oral Biology. ISSN 0003-9969. 55(3), p. 229–234. doi: 10.1016/j.archoralbio.2010.01.003. Full text in Research Archive Show summary

  Objective: The protective effect of fluoride solutions against acidic challenge on enamel was tested in vitro using calcium- and profilometer analyses. Methods: HF-, SnF2-, TiF4- and NaF solutions (0.1M F-) and H2O as negative control were tested on a total of 60 enamel specimens divided into ten groups. Prior to and after F-treatment five groups were exposed for 1min to 0.01M citric acid, and the other five groups for 10min to 0.1M citric acid. Enamel specimens were measured by profilometry at baseline and before and after each acidic challenge. [Ca] in the collected citric acid samples was measured by atom absorption spectroscopy (AAS). ΔCa and Δ surface height were calculated for each specimen and the data were analysed using one way ANOVA, Tukeys test and Pearson r correlation. Results: AAS showed that F-treatments reduced enamel dissolution for both the 1min and 10min acidic challenge. Profilometry showed no significant differences between the F-solutions for the 1min groups. Significant differences could be seen between the fluorides for the 10min groups and there was a large correlation between the profilometric and AAS results. In conclusion, all fluoride solutions reduced enamel dissolution when specimens were exposed to a typical dietary acid. Conclusions: The profilometer was not sensitive enough to measure the effects of the different fluorides against a low acidic challenge as represented by this in vitro experiment. AAS was able to show these differences and for the 10 min acidic challenge there was a good correlation between the results from the two methods.

• Thrane, Per Stanley; Jonski, Grazyna & Young, Alix (2010). Comparative effects of various commercially available mouth-rinse formulations on halitosis. Dental Health. ISSN 0011-8605. 49(1), p. 6–10. Full text in Research Archive
• Hjortsjø, Carl; Saxegaard, Erik; Young, Alix & Dahl, Jon Einar (2009). In vivo and in vitro irritation testing of low concentrations of hydrofluoric acid. Acta Odontologica Scandinavica. ISSN 0001-6357. 67(6), p. 360–365. doi: 10.1080/00016350903117118. Full text in Research Archive Show summary

  Objective. Acidic fluorides are proposed for the treatment of dental erosion. The aim of this study was to examine the irritation properties of dilute hydrofluoric acid (HF) solutions for potential use in the oral cavity. Material and Methods. Hen’s Egg Test - chorioallantoic membrane (HET-CAM): The CAM was accessed by careful dissection through the egg shell (n=36, 6 eggs/test solution) and exposed to 300 µL of the HF solutions (0.05, 0.10, 0.20 and 1.0%) under macroscope examination over 5 min. Mean time-to-coagulation and average irritation score were recorded based on appearance of hemorrhage, coagulation and lysis of the blood vessels in the membrane. Mouse skin test: Sixty male mice were randomly divided into 10 groups of 6 animals (control, 0.05, 0.10, 0.20 and 1.0% HF), shaved on the back, exposed to test solution and sacrificed after 2h or 24h. Skin samples were evaluated by light microscopy, scoring epithelial leukocyte infiltration, vascular congestion, and edema. Results. HET-CAM: 0.05% HF was slightly irritant, 0.1% HF moderately irritant, 0.2% and 1% HF were strongly irritant. 0.1-1% HF solutions were severely eye irritating. Mouse skin test: HF concentration was significantly correlated with tissue response and 24-h exposure to 1% HF-solution showed focal erosion of the epithelium and marked localized subepithelial leukocyte infiltration. Conclusion. The results of these studies suggest that accidental exposure of soft tissues to solutions containing more than 0.2% HF may be harmful.

• Hjortsjø, Carl; Jonski, Grazyna; Thrane, Per Stanley; Saxegaard, Erik & Young, Alix (2009). Effect of Stannous Fluoride and Dilute Hydrofluoric Acid on Early Enamel Erosion over Time in vivo. Caries Research. ISSN 0008-6568. 43(6), p. 449–454. doi: 10.1159/000261415. Full text in Research Archive
• Hjortsjø, Carl; Jonski, Grazyna; Thrane, Per Stanley; Saxegaard, Erik & Young, Alix (2009). The Effects of Acidic Fluoride Solutions on Early Enamel Erosion in vivo. Caries Research. ISSN 0008-6568. 43(2), p. 126–131. doi: 10.1159/000209345. Full text in Research Archive
• Thrane, Per Stanley; Jonski, Grazyna; Young, Alix & Rølla, Gunnar (2009). Zn and CHX mouthwash effective against VSCs responsible for halitosis for up to 12 hours. Dental Health. ISSN 0011-8605. 48(3), p. 8–12. Full text in Research Archive
• Young, Alix; Amaechi, Bennett T; Dugmore, Christopher; Holbrook, Peter; Nunn, June & Schiffner, Ulrich [Show all 8 contributors for this article] (2008). Current erosion indices - flawed or valid? Summary. Clinical Oral Investigations. ISSN 1432-6981. 12. doi: 10.1007/s00784-007-0180-6. Full text in Research Archive Show summary

  The problem of erosive tooth wear appears increasingly to be encountered by clinicians. An adequate way of defining and recording erosive tooth wear is essential in order to assess the extent of this clinical phenomenon, both on an individual level and in the population, and for the adequate provision of preventive and therapeutic measures. Many studies have been carried out in order to examine levels of dental erosion in the population and in one case, to look also at erosion progression. Well-established erosion indices have been used in most of these studies, although in many cases modifications have been made to suit the different research aims. This use of different indices is one reason why it still cannot be claimed that there is enough current knowledge on this clinical phenomenon. This article summarizes the proceedings of a workshop to discuss the topic of dental erosion indices. The result of the workshop is a proposal for a new scoring system (Basic Erosive Wear Examination, BEWE) designed for use both within the research field and for dental clinicians, with the aims of standardising assessment of erosion for international comparisons, raising awareness and providing guidelines for treatment of erosive tooth wear in dental practice.

• Hove, Lene Hystad; Holme, Børge; Young, Alix & Tveit, Anne Bjørg (2008). The protective effect of TiF4, SnF2 and NaF against erosion-like lesions in situ. Caries Research. ISSN 0008-6568. 42. doi: 10.1159/000112816. Full text in Research Archive
• Hove, Lene Hystad; Young, Alix & Tveit, Anne Bjørg (2007). An in vitro study on the effect of TiF4 treatment against erosion by hydrochloric acid on pellicle-covered enamel. Caries Research. ISSN 0008-6568. 41(1), p. 80–84. doi: 10.1159/000096111. Full text in Research Archive
• Hove, Lene Hystad; Holme, Børge; Young, Alix & Tveit, Anne Bjørg (2007). The erosion-inhibiting effect of TiF4, SnF2, and NaF solutions on pellicle-covered enamel in vitro. Acta Odontologica Scandinavica. ISSN 0001-6357. 65(5), p. 259–264. doi: 10.1080/00016350701477581. Full text in Research Archive
• Thrane, Per Stanley; Young, Alix; Jonski, Grazyna & Rølla, Gunnar (2007). A new mouthrinse combining zinc and chlorhexidine in low concentrations provides superior efficacy against halitosis compared to existing formulations: a double-blind clinical study. The Journal of clinical dentistry. ISSN 0895-8831. 18(3), p. 82–86. Full text in Research Archive
• Young, Alix; Thrane, Per Stanley; Saxegaard, Erik; Jonski, Grazyna & Rølla, Gunnar (2006). Effect of stannous fluoride toothpaste on erosion-like lesions: an in vivo study. European Journal of Oral Sciences. ISSN 0909-8836. 114, p. 180–183. Full text in Research Archive

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• Frigaard, Julie Mari; Hynne, Håvard; Randsborg, Karoline; Mellin-Olsen, Tonje; Young, Alix & Rykke, Morten [Show all 10 contributors for this article] (2022). Oral health indicators, oral health-related quality of life and nutritional aspects in medicated patients suffering from anxiety, psychosis, and/or depression. Frontiers in Public Health. Full text in Research Archive
• Frigaard, Julie Mari; Hynne, Håvard; Young, Alix; Hove, Lene Hystad; Rykke, Morten & Singh, Preet Bano [Show all 7 contributors for this article] (2022). Do medicated psychiatric patients differ from other dry mouth patients? Full text in Research Archive
• Hynne, Håvard; Aqrawi, Lara A.; Chen, Xiangjun; Amdal, Cecilie Delphin; Reppe, Sjur & Aass, Hans Christian Dalsbotten [Show all 14 contributors for this article] (2021). Cytokine profiling, clinical oral and ocular manifestations post radiotherapy. Full text in Research Archive
• Young, Alix; Jensen, Janicke Liaaen; Hove, Lene Hystad; Fjeld, Katrine Gahre & Blich, Carl Christian (2021). Et smil uten smerter? Full text in Research Archive
• Diep, My Tien; Jensen, Janicke Liaaen; Sødal, Anne Thea Tveit; Young, Alix; Skudutyte-Rysstad, Rasa & Hove, Lene Hystad (2020). Are Xerostomia and Hyposalivation Common Problems Among 65-Year-Olds? Caries Research. ISSN 0008-6568. 54(4), p. 449–450. doi: 10.1159/000511860. Full text in Research Archive
• Young, Alix; Singh, Preet Bano; Hynne, Håvard; Westergaard, Kristine Løken; Hove, Lene Hystad & Rykke, Morten [Show all 10 contributors for this article] (2019). Oral Investigations in Head and Neck Cancer Patients after Radiotherapy. Full text in Research Archive Show summary

  Objectives: To investigate oral complaints and findings in head and neck cancer (HNC) patients who had received radiotherapy and compare them with controls. Methods: As part of a larger study, 30 HNC patients (14 female, age 64.2±9.6y) and 26 age- and sex-matched controls (13 female, 62.9±12.9y, p=0.850) were examined at the Dry Mouth Clinic, Faculty of Dentistry, Oslo. Oral health-related quality of life (OHRQoL) was assessed using the short form Oral Health Impact Profile (OHIP-14: high score-low OHRQoL). Self-reported dysgeusia (yes/no) and sense of taste (10-point VAS: high score-good smell sense) were recorded. Taste scores were recorded using taste strips (high score-good taste function). Oral candida counts were determined from cheek and tongue swabs (0=no growth, 1=minimal, 2=moderate, 3=severe). Volatile sulphur compounds (VSC) in mouth air samples were determined by gas chromatography and related to perceptive threshold-levels (H2S≤112ppb, CH3SH≤26ppb). Between-group comparisons were performed using Mann-Whitney U test and Chi-square test. Results: The HNC patients reported significantly poorer OHRQoL than controls (OHIP sum-score: 18.4±12.4 vs 1.2±2.0, p<0.001). They reported significantly poorer sense of taste compared to controls (6.4±2.4 vs 7.8±1.9, p=0.018), and more often dysgeusia (26.7% vs 7.7%, p=0.087). The measured gustatory scores (20.4±6.4 vs 22.3±4.6, p=0.315) were similar for both groups. Candida scores were significantly higher in the patient group (1.6±1.3 vs 0.7±0.9, p=0.024). The percentage of HNC patients who had oral H2S above the threshold level was significantly lower than for the controls (0% vs 27%, p<0.05). This was not the case for CH3SH (5.5% vs 27%, p=0.105). Conclusion: After radiotherapy, these HNC patients experienced negative oral consequences of the treatment. They reported poorer OHRQoL, and had reduced taste sensation and higher oral candida counts. However, the underlying reason for less problems with halitosis in HNC patients than in controls is worth further exploration.

• Jensen, Janicke Liaaen; Chen, Xiangjun; Hynne, Håvard; Westgaard, Kristine Løken; Hove, Lene Hystad & Young, Alix [Show all 14 contributors for this article] (2019). Sjögren’s versus irradiated head-neck cancer patients: oral and ocular investigations. Full text in Research Archive
• Hynne, Håvard; Westgaard, Kristine Løken; Herlofson, Bente Brokstad; Amdal, Cecilie Delphin; Hove, Lene Hystad & Young, Alix [Show all 10 contributors for this article] (2019). Oral and Ocular Findings in Radiated Head-and Neck Cancer Patients. Full text in Research Archive
• Homayouni, Amin; Tashbayev, Behzod; Rusthen, Shermin; Hove, Lene Hystad; Rykke, Morten & Singh, Preet Bano [Show all 9 contributors for this article] (2018). Can saliva secretion affect oral malodour and oral health-related quality of life? Full text in Research Archive Show summary

  The aim of this study was to investigate the relationship between saliva secretion, halitosis and oral health-related quality of life (HRQoL). Informed consent was obtained from 65 participants including 24 patients with primary Sjögren’s Syndrome (pSS, 53±12y), 17 patients with dry eyes and dry mouth not fulfilling the classification for pSS (non-SS-sicca, 53±11y), and 24 healthy controls (49±11y). Unstimulated (UWS) and stimulated (SWS) whole saliva secretion rates were recorded as low (hyposalivation: SWS <0.7 ml/min, UWS <0.1 ml/min) or normal (SWS >0.7 ml/min, UWS >0.1 ml/min). Volatile sulfur compounds (VSC: hydrogen sulphide-H2S, methylmercaptan-CH3SH) in mouth air were measured by gas chromatography. HRQoL was assessed using the Oral Health Impact Profile-14 (OHIP-14). Mann-Whitney test was used in data analysis (p<0.05). In general, for UWS, subjects with hyposalivation had significantly higher mean CH3SH-levels than those with normal salivation (27.339.3 vs 9.913.6 ppb). For SWS, subjects with hyposalivation had significantly higher mean H2S-levels (184.5464.8 vs 43.964.1 ppb) and CH3SH-levels (27.237.4 vs 6.58.9 ppb). Within the non-SS patient group, those with hyposalivation had significantly higher H2S-levels than those with normal salivation. In general, there were no significant differences in OHIP-scores based on VSC levels. However, within the non-SS group, those with high H2S-levels (>112 ppb) reported significantly more often that they had “difficulties relaxing due to oral problems”, and that “life has been less satisfactory due to oral problems”, than those with low H2S-levels (<112 ppb). In conclusion, hyposalivation was generally associated with increased levels of oral VSC, indicating oral malodour. Surprisingly, patients with dry eyes and dry mouth who did not fulfill the classification for pSS seemed to be more affected in their daily life than patients who fulfilled the criteria.

• Langeland, Øystein; Tashbayev, Behzod; Rusthen, Shermin; Young, Alix; Herlofson, Bente Brokstad & Hove, Lene Hystad [Show all 14 contributors for this article] (2018). Comparative Ocular and Oral Findings in Sicca Complex. Full text in Research Archive
• Rusthen, Shermin; Kristoffersen, Anne Karin; Young, Alix; Galtung, Hilde; Enersen, Morten & Jensen, Janicke Liaaen (2018). The Salivary Microbiota Profile in Reduced and Normal Salivation. Full text in Research Archive
• Hynne, Håvard; Tashbayev, Behzod; Young, Alix; Herlofson, Bente Brokstad; Hove, Lene Hystad & Rykke, Morten [Show all 14 contributors for this article] (2018). Evaluation of Dry Eye Disease, Oral Dryness and Inflammatory Cytokines in Primary Sjögren´s Syndrome. Full text in Research Archive
• Hove, Lene Hystad; Young, Alix; Hjortsjø, Carl; Stevning, Karen & Løvik, Sara Emilie (2017). Effect of Whitening Toothpastes on Dental Enamel In Vitro. Full text in Research Archive
• Tashbayev, Behzod; Rusthen, Shermin; Chen, X; Utheim, Tor Paaske; Utheim, Øygunn Aass & Young, Alix [Show all 12 contributors for this article] (2017). Dry Mouth and Dry Eye Examinations of a Norwegian Cohort of Primary Sjögren´s Syndrome Patients. Full text in Research Archive
• Jensen, Janicke Liaaen; Herlofson, Bente Brokstad; Young, Alix; Hove, Lene Hystad & Galtung, Hilde (2017). Verdien av spytt. Full text in Research Archive
• Rusthen, Shermin; Young, Alix; Preet, Bano; Tashbayev, Behzod; Garen, Torhild Oddveig & Aqrawi, Lara A. [Show all 11 contributors for this article] (2017). Is Health-related Quality of Life Correlated to Oral Status in Primary Sjögren’s Syndrome Patients? Full text in Research Archive
• Singh, Preet Bano; Rusthen, Shermin; Aqrawi, Lara A.; Young, Alix; Rykke, Morten & Hove, Lene Hystad [Show all 9 contributors for this article] (2016). Chemosensory disorders, burning mouth sensation, and halitosis in patients with Sjögren’s syndrome. Full text in Research Archive
• Rusthen, Shermin; Singh, Preet Bano; Young, Alix; Aqrawi, Lara Adnan; Rykke, Morten & Hove, Lene Hystad [Show all 9 contributors for this article] (2016). Oral quality of life, salivary, gustatory and olfactory status in patients with primary Sjögren’s syndrome. Full text in Research Archive
• Young, Alix; Rusthen, Shermin; Aqrawi, Lara Adnan; Rykke, Morten; Hove, Lene Hystad & Herlofson, Bente Brokstad [Show all 9 contributors for this article] (2016). Dental health status of patients diagnosed with primary Sjögren's Syndrome. Full text in Research Archive Show summary

  This clinical study aims to assess some oral health parameters in patients diagnosed with primary Sjögren’s Syndrome (pSS), and is part of a larger project studying groups of patients suffering from dry mouth. Material and methods: Twenty female pSS patients (mean age 54±12.7y) and 32 healthy controls (mean age 50±12.4y), were recruited to the study and examined at a newly established Dry Mouth Clinic at the Faculty of Dentistry, University of Oslo, after giving written consent. A questionnaire was filled out and clinical and radiological examinations were performed. Differences between the patient and control groups were calculated using t-test or Chi-squared tests. Results: Approximately 1/3 of patients considered their general and oral health as ‘poor’ or ‘very poor’. No controls considered their general health as ‘poor’ or ‘very poor’, and only 1 control considered their oral health as ‘poor’ or ‘very poor’. Ninety percent of patients and 75% of controls had visited the dentist within the last year. There was no between-group difference in the mean number of teeth present (patients 25.5±2.7; controls 26.1±3.8). The patients had higher mean caries experience: DMFT (patients: 18.0±6.45; controls 12.9±7.26, p=0.014), FT (patients: 15.35±5.77; controls 11.28±6.10, p=0.02), and D3-5T (patients: 0.60±0.94; controls: 0.28±0.58, p=0.136). Visible plaque was observed in 30% of patients and 9.4% of controls (p=0.056). Signs of gingivitis were observed in 25% of patients and 6% of controls (p=0.054). Conclusion: Compared to controls, pSS patients reported poorer general and oral health. They had significantly higher dental caries experience, and a tendency to more plaque and gingivitis. However, the pSS patients reported visiting their dentist more regularly than the controls, suggesting an awareness of the oral consequences of reduced salivary function.

• Jensen, Janicke Liaaen; Utheim, Øygunn Aass; Chen, Xiangjun; Thiede, Bernd; Aqrawi, Lara Adnan & Rusthen, Shermin [Show all 9 contributors for this article] (2016). Searching for Disease Biomarkers for Primary Sjögren’s Syndrome Based on Oral and Ocular Patient Examinations. Full text in Research Archive
• Hove, Lene Hystad; Aqrawi, Lara Adnan; Rusthen, Shermin; Young, Alix; Rykke, Morten & Herlofson, Bente Brokstad [Show all 10 contributors for this article] (2016). Establishment of a Dry Mouth Clinic at the Faculty of Dentistry, University of Oslo, Norway. Full text in Research Archive
• Hjortsjø, Carl; Jonski, Grazyna & Young, Alix (2015). Effect of Mouth-rinsing with Two Fluoride Solutions on Enamel Solubility Using an in vivo Experimental Model. Full text in Research Archive
• Young, Alix; Stenhagen, Kjersti Refsholt; Mulic, Aida & Amaechi, Bennett T (2015). Dental erosive wear risk assessment. In Amaechi, Bennett T (Eds.), Dental erosion and its clinical management. Springer Science+Business Media B.V.. ISSN 9783319139937. p. 121–132. doi: 10.1007/978-3-319-13993-7_7. Full text in Research Archive Show summary

  This chapter presents a newly developed dental erosive wear risk assessment tool designed for use by general dental practitioners, dental educators and dental students. The tool guides the user through the most common risk factors associated with dental erosive wear, and when combined with the Basic Erosive Wear Evaluation (BEWE) or other similar scoring system, leads to a final decision on patient risk status. An initial screening section helps the dentist to decide whether it is necessary to perform a more comprehensive dental erosive wear risk assessment. When there is clearly a need for further assessment, all dental erosive wear lesions are then recorded using the index of choice, and the dentist decides how the recorded conditions will be documented. The dentist then uses the Dental erosive wear risk assessment (DEWRA) form, where dietary and oral hygiene habits, general health status and clinical conditions are evaluated using a thorough patient interview. An overall patient risk category is chosen and the section for treatment planning and advice to the patient can then be used. The last part of the chapter provides a brief explanation of the various risk factors that are included in the DEWRA form.

• Young, Alix (2014). Halitose - årsaker og behandling. In Holmstrup, Palle (Eds.), Aktuel Nordisk Odontologi 2014. Munksgaard Forlag. ISSN 9788762812512. p. 57–68. Full text in Research Archive Show summary

  Halitosis, also known as bad breath or oral malodour, is a term used to describe noticeably unpleasant odour coming from the mouth or the nearby respiratory system. This condition is reported to affect about 25 % of the population on a daily basis. Morning bad breath, experienced by many upon waking in the morning, most likely due to local oral conditions, is usually only a temporary problem that can be easily prevented or treated. However, some cases of halitosis, especially those associated with extra-oral causes can be more chronic and can adversely affect a person’s social and work situation. Dental health workers regularly meet patients who either complain of bad breath, or have halitosis without being aware of the situation. Knowledge of the usual causes of halitosis and treatment methods for oral malodour should therefore be mandatory. In this short overview the most common physiological and pathological oral causes of halitosis will be described, as well as possible extra-oral causes. Simple preventive and treatment strategies with a focus on the oral cavity will be presented.

• Hjortsjø, Carl; Young, Alix; Kiesow, Andreas; Cismak, Andreas; Berthold, Lutz & Petzold, Matthias (2013). An electron microscopic study comparing effects of human enamel exposure to SnF2-, TiF4- and NaF-solutions. Full text in Research Archive
• Hjortsjø, Carl; Jonski, Grazyna & Young, Alix (2013). A modified in vivo experimental model for evaluating fluoride treatment against initial erosion lesions. Full text in Research Archive
• Young, Alix (2012). Hvorfor får vi sovesmak i munnen? [Internet]. Forskning.no. Full text in Research Archive
• Hjortsjø, Carl; Jonski, Grazyna; Young, Alix & Saxegaard, Erik (2011). Erosive effect of acidic fluoride solutions on enamel in vitro. Full text in Research Archive Show summary

  Acidic fluoride solutions have been shown to exhibit erosion-inhibiting properties on dental enamel. The aim of this in vitro study was to investigate the possible erosive effect of dilute hydrofluoric acid (HF) on enamel. A 0.2% HF solution (0.1 mol/l F-, pH 3.02) was compared with two acidic fluorides containing 0.5 mol/l F- (3.9% SnF2-pH 2.65 and 1.6% TiF4-pH 1.42) and 1.8% citric acid (acidic control, pH 2.27). 24 human third molar enamel specimens were randomly divided into 4 groups (6 specimen/solution). Enamel surfaces were ground flat by wet grinding with a grit 2500 abrasive paper and half of each flat surface was isolated using a A-silicon impression material. The enamel surfaces were exposed to 20ml of the test solutions for ten minutes in plastic containers. The isolation material was removed. and changes in the enamel surfaces were analysed by LED blue light profilometry (λ=470 nm, 50x magnification). The specimen area analysed included both treated and untreated ground enamel, a total area of 254.64 x 190.90 µm2 for each sample. The difference in surface height between treated and untreated enamel was calculated for each specimen and etching depth data were analysed using oneway ANOVA and Tukeys test. The mean etching depths (µm±SD) were 0.14(0.86), -2.00(0.52), -3.25(2.91) and 5.42(1.00) for, HF, SnF2, TiF4 and control respectively. HF had significantly less etching effect than the control, but was significantly more erosive than TiF4 (p<0.05). In conclusion, while both SnF2 and TiF4 treatments resulted in an average deposition on the enamel surface, HF showed an average etching effect close to zero. Further studies are needed to examine the mechanism of the previously described anti-erosive effect of HF.

• Young, Alix; Hjortsjø, Carl; Berthold, Lutz; Cismak, Andreas & Petzold, Matthias (2011). An electron microscopic study of enamel treated with hydrofluoric acid. Full text in Research Archive Show summary

  Previous studies have demonstrated the effectiveness of treating enamel with acidic fluorides as a means of reducing the effects of erosive challenges. The aim of the present in vitro study was to investigate the surface characteristics of dental enamel treated with hydrofluoric acid (HF). Natural surfaces of enamel specimens from extracted human third molars were treated for 10 min with either native solutions of HF (pH 3) or sodium fluoride (NaF, pH 7) containing both 0.1 and 0.2 mol/l F-. Untreated samples functioned as controls. All specimens were examined by SEM/EDX with respect to surface microstructure variation and fluoridation. For selected specimens, samples were prepared by FIB allowing cross-sectional investigations using TEM and nanospot-EDX. Following treatment with HF, SEM/EDX analyses did not show obvious erosive damage but clearly indicated surface fluoridation. Using TEM, an enamel surface microstructure modification to a depth of approximately 200 nm with a clear boundary to non-affected apatite was revealed. The fluoride content in this layer was above 40at% F with a F/Ca ratio of roughly 2 indicating the transformation of surface hydroxyapatite into CaF2-like material. In previous studies, isolated fluoride-rich globular precipitates were found if medium-acidulated solutions of NaF were applied. The atomic composition of the HF-induced CaF2-like material resembled that of these precipitates. In contrast, no fluoridation effects were found for the NaF at pH 7 and the controls in this study. These results suggest that the general reaction between fluoride solutions and enamel leading to a formation of CaF2-like material does not significantly depend on the dissociated fluoride cation. On the other hand, the reaction rate for the acidic HF treatments is higher since the amount of dissolved calcium increases with decreasing pH.

• Young, Alix; Jonski, Grazyna & Rølla, Gunnar (2010). Dental erosion inhibition by SnF2 and TiF4 compared with the effect of HF. Full text in Research Archive Show summary

  Background: The aim of this in vitro pilot study was to compare the effect of three acidic equimolar fluoride solutions (and subsequent water treatment to remove all un-reacted fluoride) on the acid resistance of teeth. Cleaned whole teeth (n=24, 6 teeth/group) were each pre-etched by immersion in 10 ml-aliquots of 0.1 mol/L citric acid for 5 min. The teeth were then incubated in 10 ml of the test fluoride solutions containing 0.1 M F: SnF2 (pH 2.9), TiF4 (pH 1.5) or hydrofluoric acid (HF, pH 2.0) for 20 min. Six teeth were not treated with any fluoride (control). Teeth were then incubated in distilled water for 24 h before re-etching as for the pre-etch. The citric acid solutions before and after F-treatment were retained for Ca-analysis using atom absorption spectroscopy. Mean pre- and post etch [Ca] for each F-solution and % ΔCa were calculated for each F-solution and for the control. Mean pre-etch [Ca] and mean post F-treatment [Ca] with (SD) results in mg/L were for HF: 8.894 (2.52) and 1.418 (1.188); SnF2: 8.201 (1.92) and 2.525 (1.19); TiF4: 7.683 (1.75) and 2.822 (0.93) and control: 7.318 (2.31) and 7.470 (1.69). The % reduction in Ca dissolution was 86, 70, 64 and -6, for HF, SnF2, TiF4 and the control respectively. At this low fluoride concentration, HF was more effective than the two metal fluorides, suggesting that the metal ions may not contribute directly to the inhibition of mineral dissolution. The role of the metal ions may be to provide an acidic environment in these solutions (and formation of HF), as they react with the hydroxyl ions of water during the solubilization of their salts.

• Young, Alix (2010). Halitose – et åndelig problem? Full text in Research Archive
• Young, Alix (2010). Halitose. Full text in Research Archive
• Young, Alix (2009). Halitose. Full text in Research Archive
• Young, Alix (2009). Halitose. Full text in Research Archive
• Hjortsjø, Carl; Jonski, Grazyna; Saxegaard, Erik & Young, Alix (2009). Profilometric study of the effects of acidic fluoride solutions on early dental erosion. Full text in Research Archive Show summary

  An in-vivo experimental model for dental erosion has been utilised to assess the effects of treating dental enamel with fluorides. This in-vitro study aimed to examine the effects of the same acidic fluoride solutions using profilometry. Crowns of intact, surgically extracted human third molar teeth were cut into 2-4 pieces, washed (deionised water, 50% ethanol then 96% ethanol), embedded in acrylic resin and polished (grit 4000). Nail varnish was applied in a line across the block separating the enamel surface from the acrylic resin surface. Specimens were exposed to 5 ml of 100 mmol/L citric acid for 10 min before (etch I) and after (etch II) fluoride treatments. Aqueous solutions of TiF4, SnF2, HF or NaF, (all 0.1 M F-) and deionised water (negative control) were tested (n=6 specimens/test solution). All solutions were applied in a cell culture well (Nunclon, Nunc, Roskilde, Denmark) and enamel specimens were exposed to all the fluids in these wells. Specimens were analysed at all stages in a high power LED blue light profilometer (PLµ2300 Optical Imaging Profiler, Sensofar Tech, Spain) at 150x magnification and λ=470 nm. Areas including one half of exposed enamel and the other half varnish-covered enamel (220.98 x 165.68µm) were analysed to a depth of 40µm. Data analysis compared the step-height differences between the exposed and the varnished reference areas. Paired t-test and Kruskal-Wallis ANOVA on Ranks were used in the statistical analysis. There was a significant reduction in step height difference following HF-, SnF2-, and TiF4-treatments (p ≤0.005), but not for the NaF and water. The acidic fluoride solutions were capable of reducing the erosive effect of the citric acid challenge as previously shown in the in vivo experimental model.

• Hjortsjø, Carl; Jonski, Grazyna; Saxegaard, Erik & Young, Alix (2009). Validation of a dental erosion model I–chemical analysis in-vitro. Full text in Research Archive Show summary

  An in vivo experimental model for dental erosion has been utilised to assess the effects of treating dental enamel with fluorides as a preventive and/or treatment measure. Objective: To validate the in-vivo experimental model results in-vitro using chemical analysis. Methods: Crowns of intact, surgically extracted human third molar teeth were cut into 2-4 pieces, washed (deionised water, 50% ethanol, 96% ethanol), embedded in acrylic resin and polished (grit 4000). Specimens were exposed to 5 ml of 10 mmol/L citric acid for 1 min before (etch I) and after (etch II) fluoride treatment. Aqueous solutions of TiF4, SnF2, HF and NaF (all 0.1 M F-) and deionised water (negative control) were tested (n = 6 tooth specimens/test solution). The citric acid and test solutions were applied using a peristaltic pump (flow: 6 ml/min, Gilson model Minipuls 3). Etch and fluoride solutions were collected in coded tubes and analysed blind for calcium content using atomic absorption spectrometry (Model 3300, Perkin Elmer Analytical Instruments, USA) using air-acetylene flame and λ = 422.7 nm. ∆ ppm calcium (etch I minus etch II) was calculated for each tooth and mean percentage reduction in calcium loss was determined for each test solution. Results were analysed using one way ANOVA and the Bonferroni t-test for multiple comparisons. Results: The HF- and SnF2-treatments were significantly more effective in reducing calcium dissolution than the TiF4 and NaF-treatments (p≤0.004). There was no statistical difference between TiF4 and NaF- treatments (p=0.138). The water control resulted in an increase in calcium dissolution. Conclusion: These results correlate well with results from the in vivo model and help validate the use of calcium analysis in the in-vivo dental erosion model.

• Young, Alix; Hjortsjø, Carl; Saxegaard, Erik & Jonski, Grazyna (2009). A study on the effect of age on enamel dissolution using a dental erosion model. Full text in Research Archive Show summary

  The prevailing expert opinion suggests that there is little evidence to support the concept that pathological levels of dental erosion are age-dependant. However, some evidence seems to indicate that normal levels of erosion may be age-dependant. Many factors may contribute to this type of wear and presumably the enamel solubility is one of these factors. An in-vivo experimental model for dental erosion using volunteers of various ages has been utilised to assess the effects of treating dental enamel with fluorides to reduce damage due to erosion. The aim of the present study was to examine the possible relationship between the age of the test individuals and the degree of enamel dissolution upon acidic challenge. The in-vivo model has been described previously. In 176 test subjects (age range 18 - 69 years), labial surfaces of 342 healthy anterior teeth were exposed to 5 ml 0.18% citric acid, at 6 ml/min using a peristaltic pump. The acid was collected in coded test tubes for blind analysis of calcium content using atom absorption spectrometry. Mean calcium concentration was calculated separately for central incisors (0.924 mg/L, range 0.033-4.434) and lateral incisors (0.654 mg/L, range 0.051-3.048). The age of the subjects was not normally distributed with a mean age of 27.8 years. Statistical analysis using Spearman’s rho showed no correlation between the age of the test subjects and the calcium concentration in the acid etch (central incisors rs = 0.048, lateral incisors rs = 0.161, p<0.05). Despite the skewed age distribution these results do not support a correlation between age and degree of enamel dissolution following a brief acidic challenge.

• Hjortsjø, Carl; Dahl, Jon Einar; Saxegaard, Erik & Young, Alix (2008). HET-CAM testing of diluted hydrofluoric acid solutions. Full text in Research Archive Show summary

  It has been suggested that diluted hydrofluoric acid (HF) solutions (≤ 0.2%) can reduce enamel dissolution in a clinical dental erosion model. The toxic effect of concentrated solutions of HF is well known. The possible effects of low concentrations of HF are less well known. This study aimed to examine the irritative effects of four HF solutions (1%, 0.2%, 0.1% and 0.05%) using the Hen’s Egg Test - chorioallantoic membrane (HET-CAM) (Kalweit et al., Toxicol in Vitro 1990;4:702-706). The hypothesis to be tested was that low concentrations of HF do not provoke any response on the blood vessels of the CAM of fertilized hens’ eggs. The CAM was accessed by careful dissection through the egg shell. 300 μl of the test solutions was dripped on the CAM under constant examination using a macroscope. The time for appearance of haemorrhage, vessel lysis and coagulation in the membrane was recorded. An average irritation score (IS) for each test solution (n=24 eggs in total) was calculated and a score was assigned: 0-0.9 = non irritant, 1-4.9 = slight irritant, 5-8.9 = moderate irritant and 9-21 = strong irritant. Mean time to coagulation (mtc100) was also calculated, values below 100 were classified as R41 - severely eye irritating. Results showed that 0.05% HF scored as slightly irritant (IS=3.26), 0.1% HF as moderately irritant (IS=7.49) while both 0.2% and 1% HF were recorded as strongly irritant (IS=9.92 and 12.22 respectively). 0.1%, 0.2% and 1% HF were classified as severe eye irritants (mtc100= 75, 80 and 50). In conclusion all four HF solutions provoked reactions on the chorioallantoic membrane of fertilized hen’s eggs. Care must therefore be taken when using diluted HF solutions under experimental clinical conditions.

• Hjortsjø, Carl; Jonski, Grazyna; Rølla, Gunnar; Thrane, Per Stanley; Saxegaard, Erik & Young, Alix (2008). Short term effect of NaF-, SnF2- and dilute HF-treatments on enamel erosion-like lesions in vivo. Full text in Research Archive Show summary

  Dental erosion is a clinical problem in many countries today partly due to increased exposure to dietary acids. Citric acid for example is commonly found in fruit juices, mineral water, flavoured teas and bottled still water. Recent studies have shown that several acidic fluoride preparations hold promise in the prevention and treatment of dental erosion. This study aimed at comparing the effect of sodium fluoride (NaF, pH 7.3), stannous fluoride (SnF2, pH 2.9) and dilute hydrofluoric acid (HF, pH 2.0) solutions, on enamel dissolution in an experimental in vivo model as described previously (Young et al., Eur J Oral Sci 2006;114;180-183). Four healthy anterior teeth in each subject (n=29) were isolated using plastic strips and a light bodied impression material for complete palatal coverage. The labial surfaces of the test teeth were exposed to 5 ml citric acid (0.18%) using a peristaltic pump (6 ml/min), before (etch I) and 5 min after (etch II) application of test fluoride preparations. The acid was collected in a test tube for later analysis. NaF, SnF2 or HF solutions (all 0.1 M F-) were applied to the labial surfaces of the teeth for 1 min using a peristaltic pump (6 ml/min). Enamel dissolution was examined by measuring calcium content in the citric acid using atom absorption spectrometry. Mean values for etch I minus etch II were calculated and statistical analysis with the Bonferroni t-test for between group comparisons. HF and SnF2 gave mean calcium reductions of 0.37 ppm (76%) and 0.67 ppm (68%) respectively (NS). NaF gave no calcium reduction (-0.34 ppm (-52%). In conclusion, while neutral NaF had no protective effect 5 min after treatment, SnF2 and dilute HF markedly reduced calcium loss.

• Young, Alix (2008). Halitose. Full text in Research Archive
• Young, Alix (2008). Halitose. Full text in Research Archive Show summary

  Halitose. Hvorfor har vi dårlig ånde og hvordan behandler vi det? Emnet er fortsatt tabubelagt, men alle i tannpleien bør kunne gi pasienter best mulig råd. De fleste årsaker til dårlig ånde skyldes lokale faktorer i munnhulen og kan lett behandles. Foredraget vil inneholde en gjennomgang av årsaker og sammenhenger og forskningsbaserte tips for behandling.

• Young, Alix (2008). Halitose. Full text in Research Archive Show summary

  Halitose. Hvorfor har vi dårlig ånde og hvordan behandler vi det? Emnet er fortsatt tabubelagt, men alle i tannpleien bør kunne gi pasienter best mulig råd. De fleste årsaker til dårlig ånde skyldes lokale faktorer i munnhulen og kan lett behandles. Foredraget vil inneholde en gjennomgang av årsaker og sammenhenger og forskningsbaserte tips for behandling.

• Young, Alix (2008). Halitose. Full text in Research Archive Show summary

  Halitose. Hvorfor har vi dårlig ånde og hvordan behandler vi det? Emnet er fortsatt tabubelagt, men alle i tannpleien bør kunne gi pasienter best mulig råd. De fleste årsaker til dårlig ånde skyldes lokale faktorer i munnhulen og kan lett behandles. Foredraget vil inneholde en gjennomgang av årsaker og sammenhenger og forskningsbaserte tips for behandling.

• Hjortsjø, Carl; Jonski, Grazyna; Saxegaard, Erik; Thrane, Per Stanley & Young, Alix (2007). Effect of time on dilute hydrofluoric acid-treatments of enamel in vivo. Full text in Research Archive Show summary

  Dental erosion is currently considered to be one of the main reasons for tooth wear. It has been suggested in an in vivo study that hydrofluoric acid (HF) successfully reduces enamel dissolution and protects enamel against acidic challenges. The aim of this study was to evaluate the protective effect of 0.2% HF solution over time, using a newly established indirect experimental in vivo model. Test subjects (n=28) took part in this study. Healthy anterior teeth (n=107) with intact pellicle were kept dry during the experiment using cotton rolls and saliva suction, and isolated using plastic strips and a light-bodied impression material for complete coverage of palatinal surfaces. The labial surfaces were exposed to diluted citric acid (10mmol/l) using a peristaltic pump (5ml, 6ml/min). The acid was collected in a test tube before (etch I) and after 24 h (n=54 teeth) or 7 days (n=53 teeth) (etch II), following application of aqueous 0.2% HF solution (6ml, 6ml/min). The teeth were rinsed for 5s with water after both etch I and II. Enamel dissolution was examined by assessment of calcium content in the citric acid of etch I and II using atom absorption spectroscopy. The reductions in calcium content in the citric acid between etch I and etch II were calculated for each tooth (p< 0.05). A significant reduction in post HF-treatment calcium loss was observed for both time periods, though the protective effect decreased with time. Mean percent calcium loss reduction was 49 (S.E. 3.6) for the 24-h group and 29 (S.E. 5.4) for the 7-d group. The results suggest that 0.2% HF has a protective effect on sound enamel that lasts for at least one week.

• Young, Alix; Thrane, Per Stanley; Saxegaard, Erik; Hjortsjø, Carl; Jonski, Grazyna & Rølla, Gunnar (2006). Preventive effects of acidic fluoride treatments on erosion-like lesions. Full text in Research Archive
• Young, Alix; Thrane, Per Stanley; Saxegaard, Erik; Hjortsjø, Carl; Jonski, Grazyna & Rølla, Gunnar (2006). Preventive effect of acidic fluoride treatments on erosion-like lesions. Full text in Research Archive Show summary

  Dental erosion is an increasingly important clinical problem and treatment of serious cases often both difficult and expensive. Prevention and treatment involving fluoride application in various forms has been studied both in vitro and in situ. Objectives: To compare the effect of acidic fluoride against neutral fluoride on erosion-like lesions using an in vivo model. Methods: Four healthy anterior teeth in each subject (n=40) with intact pellicle were individually exposed to citric acid (100mmol/l or 10mmol/l) applied using a peristaltic pump (5ml, 7ml/min) and the acid collected in test tubes before (etch I) and after (etch II) applications of the respective fluoride preparations. Fluoride toothpastes (0.15% NaF and 0.4% SnF2) were applied to the labial surfaces with a soft brush (4 x 1min) with gentle water rinsing between applications. Fluoride solutions (0.15% HF, pH 2.5 and 0.35% NaF, pH 8.8) were dripped continuously on the labial surfaces of each tooth (1 min, 4 ml/min), followed by 5 s water rinse/tooth. Subjects rested 1 min prior to etch II. Enamel solubility was examined by assessment of calcium content (Ca) in etch I and II using atom absorption spectroscopy. Results: Toothpastes – SnF2 provided far better protection of the enamel than NaF reducing Ca-loss by 20% when the weakest acid was used. NaF resulted in large Ca-loss with both acid concentrations. Solutions – HF reduced Ca-loss by 60 % whereas the NaF resulted in large Ca-loss with both acid concentrations. Conclusions: The experiments showed that SnF2 and highly dilute HF are promising preventive treatment measures for dental erosion.

• Rølla, Gunnar; Jonski, Grazyna; Saxegaard, Erik & Young, Alix (2006). Effect of acidified fluoride solutions on dissolution rate of enamel in erosive acid. Full text in Research Archive Show summary

  It is well known that aqueous solutions of SnF2 and TiF4 reduce the dissolution rate of enamel in erosive acid, and it has recently been shown that highly diluted solutions of hydrofluoric (HF) acid shares this property. All these solutions have “natural” acidity, and induce formation of calcium fluoride on enamel. Objective: To compare the dissolution-reducing capacity of HF with NaF acidified with HCl or H3PO4. The latter are also known to cause calcium fluoride formation. Material and methods: The diluted HF and acidified NaF-solutions all had a pH of 3 and contained 0.09% fluorine. Enamel samples (n=18) were individually pre-treated with 10ml of 0.01M citric acid for 10 min (Etch 1) and the amount of calcium released measured by atomic absorption. These enamel samples were subsequently treated with one of the fluoride containing solutions for 10 min, and again etched and analyzed as before (Etch 2). The difference between Etch 1 and Etch 2 was assumed to be due to the respective fluoride treatments. Data were analysed using one way ANOVA. Results: It was found that the HF-treatment was more effective than treatment with acidified NaF-solutions. Mean reductions were HF - 50%, NaF with H3PO4 - 30% (p=0.26) and NaF with HCl - 20% (p=0.03). Conclusion: As HF contains mainly un-dissociated molecules at pH 3, it is suggested that these very small, uncharged molecules of covalently bound H and F, can diffuse rapidly together into enamel, opposed to ionic F-Na+ in acidified solutions. The HF molecules can form calcium fluoride as follows: CaHPO4 + 2HF > CaF2 + H2PO4 + H+. The acids used with NaF are fully dissociated and these protons are free to individually penetrate into enamel and cause mineral loss. The movement of fluoride is however restricted due to its high affinity for Na.

• Saxegaard, Erik; Young, Alix; Hjortsjø, Carl; Jonski, Grazyna & Rølla, Gunnar (2006). Dentin pre-treatment with diluted hydrofluoric acid reduces solubility. Full text in Research Archive Show summary

  We have previously reported that enamel and cementum are protected against dissolution in citric acid by brief pre-treatments with highly diluted hydrofluoric acid (HF, pH=3). (Saxegaard et al IADR 2005). Deposition of calcium fluoride-like material (hereafter CaF2) was shown to account for the effect which was also concentration dependent. However, advanced cases of dental erosion may penetrate the enamel and reach the dentin. Objective: To examine the effect of similar pre-treatments on the solubility of dental dentin. Methods: In 42 intact human third molars the dentin was exposed by cutting off the tooth-enamel using a diamond bur. The roots were cut off and the exposed cervical surface covered with acid-resistant nail varnish. In 6 groups each specimen was treated with 0.1M citric acid (10ml, 30min) before (etch-I) and after (etch-II) treatment with the different HF-solutions ((0.1%-1.0%, 10ml, 10min). Samples were briefly rinsed in deionised water between treatments. Dissolution of dentin was assessed by comparing the calcium content in etch I and II using atomic absorption spectroscopy. Remaining dentin samples similarly underwent etch I and various HF-treatments before examination in EDXA and SEM (Phillips type XL30 ESEM). Results: Treatment with 0.1%HF reduced the solubility of dentin by ~80%, whereas 0.2-1.0%HF gave reductions of 93-98%. This reduction was somewhat lower than for cementum but higher than for enamel. SEM images showed that dentin was covered with a CaF2, whereas results of EDXA analyses were inconsistent. Conclusion: As with enamel and cementum the CaF2 produced on dentin in the presence of HF appears to exert a protective effect against clinical erosion. It can be speculated that the effect may be due to the low pH at which the CaF2 was formed. It seems likely that the nature of the phosphate contamination of the CaF2 determines its rate of dissolution in erosive acids.

• Hjortsjø, Carl; Jonski, Grazyna; Thrane, Per Stanley; Rølla, Gunnar & Young, Alix (2006). Effect of dilute hydrofluoric acid-treatments on enamel in vivo. Full text in Research Archive Show summary

  Dilute hydrofluoric acid (HF) solutions have in earlier tests been proven to reduce enamel solubility. Objectives: To examine the effect of different concentrations of dilute HF in reducing enamel solubility using an in vivo model. Methods: Four healthy anterior teeth in each subject (n=72) with intact pellicle were exposed to diluted citric acid (10mmol/l) applied using a peristaltic pump (5 ml, 6 ml/min) and the acid collected in a test tube before and after application of the respective HF preparations (etch I and etch II). Four different concentrations of HF solutions (0.20%, 0.15%, 0.10%, 0.05%) where dripped on the labial surfaces of each of 18 teeth using the peristaltic pump (1 min, 6 ml/min). The teeth where rinsed for 5s with water between applications and left for five minutes after the treatment with HF before etch II. Enamel solubility was examined by assessment of calcium content in the citric acid applied before and after the treatment with the HF solutions using atom absorption spectroscopy. The reductions in calcium content in the citric acid between etch I and etch II were calculated for each tooth. Results: A greater reduction in calcium loss was observed for the three most concentrated solutions (0.20% HF – 69.7%, 0.15% HF – 61.6%, 0.15% HF – 70.1%) compared to the least concentrated solution (0.05% HF – 41.2%). Conclusions: Even extremely diluted HF seems to provide a very promising level of protection against the effects of acid on enamel solubility. Further studies are planned to determine the clinical relevance of these findings.

• Rølla, Gunnar; Young, Alix; Saxegaard, Erik & Jonski, Grazyna (2006). On calcium fluoride formation on enamel. Full text in Research Archive Show summary

  A controversy exists concerning the role of calcium fluoride deposited on enamel during fluoride treatments. Some authors maintain that such calcium fluoride can protect enamel surfaces from erosive acids, whereas others claim that calcium fluoride is soluble in such acids. We have shown that calcium fluoride formed on enamel at neutral pH after exposure to 0.5 mol/l of an aqueous solution of NaF for 24 h, was unable to protect the enamel against 0.1 mol/l of citric acid for 30 min, whereas a similarly treated enamel (0.5 mol/l of an aqueous solution of hydrofluoric acid for 10 min with a pH of 3), did protect the enamel almost completely. The aim of this abstract was to discuss these results. It is suggested that the difference in dissolution rates may depend on the nature of the phosphate contaminations found in calcium fluorides formed on enamel. These phosphate contaminations originate from the enamel and are probably in the form of calcium phosphates. More acid-soluble phosphates are available on the enamel surface at pH 7, than at pH 3. These are dibasic/monobasic phosphates, and monobasic phosphate/phosphoric acid, respectively. It is also suggested that undissociated HF which is the major component of hydrofluoric acid at pH 3, may have an important role in calcium fluoride formation as previously shown [Larsen and Jensen: Caries Res 1986; 20:56-64]. It is thought that HF can probably get closer to the intercrystalline regions on the enamel due to its uncharged state, than the charged species of fluoride. The use of NaF in acidic fluoride solutions may be unfortunate in this respect, as Na inhibits the formation of HF due to its extremely high affinity for fluorine.

• Young, Alix; Thrane, Per Stanley; Saxegaard, Erik; Jonski, Grazyna & Rølla, Gunnar (2006). A clinical model for evaluating fluoride treatment of erosion-like lesions. Full text in Research Archive Show summary

  Dental erosion is an increasingly important clinical problem and treatment of serious cases often both difficult and expensive. Prevention and treatment involving fluoride application in various forms has been studied both in vitro and in situ. The present in vivo model was developed to examine the effect of fluoride on erosion-like lesions. Results are presented for two fluoride toothpastes. Material and methods: Four healthy anterior teeth in each subject (n=20) with intact pellicle were exposed to diluted citric acid (100mmol/l or 10mmol/l) applied using a peristaltic pump (5 ml, 7 ml/min) and the acid collected in a test tube before and after application of the respective toothpastes (etch I and etch II). Toothpastes (neutral 0.15 % NaF and acidic 0.4 % SnF2) were applied to the labial surfaces with a soft brush (4 x 1min) with gentle water rinsing between applications. Each subject had one pair of teeth treated with each of the test toothpastes. Enamel solubility was examined by assessment of calcium content in the citric acid applied before and after the treatment with toothpaste. Results: SnF2-toothpaste reduced the solubility of teeth in vivo by 20 % (etch II < etch I). NaF-toothpaste provided no protection (etch II > etch I). Conclusion: This model promises the possibility for studying the effect of preventive treatment measures for dental erosion. SnF2 toothpaste is more effective than NaF in preventing loss of enamel due to acid attack.

• Skaar, Mari; Mulic, Aida; Hove, Lene Hystad; Young, Alix & Tveit, Anne Bjørg (2006). Erosive effect of acidic drinks and acids on bovine enamel in vitro. Full text in Research Archive
• Saxegaard, Erik; Jonski, Grazyna; Young, Alix & Rølla, Gunnar (2005). Dilute hydrofluoric acid reduces solubility of cementum in citric acid. Full text in Research Archive Show summary

  It has been reported that pre-treatment with diluted aqueous solutions of hydrofluoric acid (HF) reduced the solubility of human dental enamel in 0.1M citric acid between 50-100% (Saxegaard et al #3272 IADR 2005). The effect was concentration dependent. OBJECTIVE: To examine the corresponding solubility reducing effect on dental cementum by a similar series of aqueous solutions of HF. METHODS: [HF] ranging from 0.1% to 1.0% was examined. Intact human third molars (n=36) were cut at the collum and the exposed cervical dentin and pulp was covered with acid-resistant nail varnish while the root cementum was carefully cleaned and lightly polished with pumice, using a rubber cup in a slow speed handpiece. In six groups (n=6) each specimen was initially treated in 0.1M citric acid (10ml, 30 min), rinsed briefly with water and dried. Samples were then pre-treated with different concentrations of HF (10ml, 10min), rinsed and dried as before, and then re-exposed to 0.1M citric acid (10ml, 30min). Solubility of the cementum was determined by measuring [Ca2+] using atomic absorption spectroscopy. Reduction in dissolution between the first and second exposure was assumed to be due to the HF-treatment. Additional cementum samples treated with HF dilutions were examined by EDXA and SEM (Phillips type XL30 ESEM). RESULTS: HF in the range 0.1-1.0% reduced the solubility of cementum by 97-100%. The pre-treated cementum was covered with a dense layer of a calcium fluoride-like material. Since cementum contains more protein than enamel, and the mineral crystals are smaller than in enamel, the mechanism of dissolution of cementum is most likely different from that of enamel. CONCLUSION: It appears that the calcium fluoride produced in the presence of HF is acid resistant and may exert a protective effect against clinical erosion of the cementum.

• Jonski, Grazyna; Saxegaard, Erik; Young, Alix & Rølla, Gunnar (2005). A comparison of biological activities of three SnF2-containing toothpastes. Full text in Research Archive Show summary

  Freshly made aqueous solutions of SnF2 exhibit a solubility-reducing effect on enamel in erosive acids, and can inhibit oral malodour by interaction with volatile sulphur compounds (VSC) which may form in the mouth. It is unclear to what extent these biological activities are present in SnF2-containing toothpastes, it is known that both the [F-] and [Sn2+] may be reduced. OBJECTIVE: The aim of the present study was to assess the biological activities outlined above in three commercial toothpastes containing SnF2 in slightly different concentrations. METHOD: Three toothpastes containing 0.14%, 0.15% and 0.10% F respectively were tested. Aqueous extracts of the toothpastes (toothpaste/water 1:3) were incubated 1 h and centrifuged at 10000 x g for 30 min. Solubility reduction: hydroxyapatite granules (HA) were treated with the respective toothpaste extracts for 10 min, washed, dried and exposed to 10 ml 0.1M citric acid for 30 min. Solubility was compared with that of untreated HA by calcium analyses of the acid using atomic absorption spectroscopy. Inhibition of VSC formation: Human saliva (n=6) was incubated overnight at 37oC, resulting in production of copious amounts of VSC. 10-ul aliquots of the toothpaste extracts were added to 1-ml saliva samples, and the VSC in the tubes compared with the untreated control using gas chromatography. RESULTS: Solubility reduction was about 40 % for the toothpastes. Toothpaste B was numerically best, followed by A and C, but there were no statistically significant differences. This reflects probably the different fluoride concentrations. Anti-VSC effects were of the same order of magnitude with A, B and C inhibiting VSC 97-99%, indicating available Sn2+. CONCLUSION: The experiments showed SnF2 toothpaste can be a vehicle for solubility-reducing activity, and that Sn2+ is also available.

• Rølla, Gunnar; Lamolle, Sebastien Francis; Young, Alix; Jonski, Grazyna & Saxegaard, Erik (2005). Comparison of the properties of CaF2-like particles formed under different conditions. Full text in Research Archive Show summary

  Treatment with dilute hydrofluoric acid (HF) induces the immediate formation of a continuous layer of CaF2-like particles on dental enamel. This is associated with a marked cariostatic effect. More recently it was observed that this treatment reduced the solubility of enamel in erosive acid and that this effect was concentration dependent. It has been suggested that deposition of CaF2-like material may provide protection of the underlying enamel and that the amount of such material formed could be essential. OBJECTIVE: To examine the CaF2-like particles formed by treatment of enamel with either neutral or acidic fluoride. METHOD: Tooth enamel specimens (n=6) were treated with either1% NaF (0.5M F-) at neutral pH for 24h, or 1% HF (0.5M F-) for 10 min. The solubility of the CaF2-like particles formed on the specimens was examined by exposing them to 0.1M citric acid for 30 min. Acid was analysed for Ca2+ by atomic absorption spectroscopy. The enamel samples were also examined by atomic force microscopy (AFM) and by SEM. RESULTS: It was found that enamel solubility was reduced 96% by HF and 6.2% by NaF. Effect of NaF was not significantly different from the control (p<0.000). AFM showed that the amount of particles formed during the two different treatments was of the same order of magnitude, that they covered the whole surface of the enamel and that they had a similar particle size of ~20 nm diameter. SEM showed that a complete layer of CaF2-like material covered the enamel. HF-treatment gave particles which were resistant to 0.1M citric acid for 30 min and to KOH for 24h (here some of the material was lost). CONCLUSION: HF treatment thus seems to give a very resistant enamel surface, presumably due to low solubility of the CaF2-like material formed under these conditions.

• Young, Alix; Hove, Lene Hystad; Kohli, Priya & Tveit, Anne Bjørg (2005). An in vitro study on the effect of titanium fluoride pre-treatment of enamel against acid attack. Full text in Research Archive Show summary

  Today�s lifestyle in many ways promotes the acidic destruction of tooth substance: dental erosions. Simple measures are needed to prevent serious treatment problems after long exposure to acids. The aim of the present study was to examine the effect of fluoride treatment (simulating professional F-application) on enamel exposed to an acidic challenge aimed at simulating gastric reflux. 16 bovine anterior teeth were sectioned to obtain 4 pieces large enough to locate a circular enamel window (4mm diameter). Nail varnish was used to block out the surrounding tooth substance. Specimens were dealt into 4 groups: group 1- control (no treatment), group 2- pellicle (2-h); group 3- titanium fluoride (TiF4) pre-treatment (2min, 0.5M F-) and group 4- pellicle + TiF4 pre-treatment. Pellicle was created by 2-h incubation of tooth specimens in freshly collected, clarified paraffin wax-stimulated human whole saliva pooled from 5 healthy subjects. Specimens in groups 3 and 4 were then subjected to 3-ml TiF4-solution for 2min under gentle agitation. All specimens were subsequently subjected to 3ml 0.01M HCl stepwise for 4+4+4 min, and the acid aliquots retained for calcium analysis in a Model 3300 Atomic Absorption Spectrophotometer, Perkin Elmer Analytical Instruments (Norwalk, CT, USA). Statistical analysis (one-way ANOVA/Bonferroni) showed that TiF4 reduced Ca-release from enamel by 75, 62 and 57% respectively compared with the control after the three acid exposures (p<0.05). The effect of TiF4 on pellicle-covered enamel was slightly better than for TiF4 alone, but this was not significant. These results may suggest that pre-treatment of enamel with a TiF4 solution with or without pellicle-removal provides protection for the enamel against acid attack.

• Rølla, Gunnar; Saxegaard, Erik; Jonski, Grazyna & Young, Alix (2005). The solubility-reducing effect on teeth by SnF2. Full text in Research Archive Show summary

  It is well established that stannous fluoride (SnF2) reduces the solubility of teeth, whereas stannous chloride or sodium fluoride salts have no such effect. Objective: To examine whether fluoride at the concentration and pH at which it is present in 0.4% SnF2, can reduce solubility of teeth without the presence of Sn2+. As the pH of an aqueous solution of 0.4 % SnF2 is 3, due to an immediate hydrolysis reaction (Sn2+ +2H2O > Sn(OH)2 +2H+), it appears that the fluoride part of the SnF2-molecule is always exposed to acidic conditions. This fluoride is thus present as partly non-dissociated hydrofluoric acid (HF). Methods: Whole intact human premolars were pre-treated with 0.4% SnF2 or 0.1% HF (10 min) and then exposed to 0.1M citric acid or 0.01M HCl (30 min). Tooth solubility after acid exposure was estimated by measuring the [Ca2+] in the acids, by atomic absorption spectroscopy. Teeth were also examined by EDXA and SEM (Phillips type XL30 ESEM). Results: Solubility reduction by both 0.4% SnF2 and 0.1% HF were similar in both acids, and not statistically different. This indicated that the fluoride part of SnF2 alone accounts for its solubility reduction and that Sn2+ appears only to provide a suitable pH for the fluoride. The teeth treated with HF were covered with dense layers of CaF2, which probably caused the solubility reduction in acids. Conclusion: It is thus possible to separate the solubility reduction by stannous fluoride from stannous ions. As stannous ions may cause discoloration of teeth, and tend to be both oxidized and hydrolyzed during storage, the aqueous solution of HF may have advantages and be of potential interest in the prevention of dental erosions.

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