Johan Caspar Wohlfahrt

• Khan, Sadia Nazir; Koldsland, Odd Carsten; Roos-Jansåker, Ann-Marie; Wohlfahrt, Johan Caspar; Verket, Anders & Mdala, Ibrahimu [Show all 9 contributors for this article] (2023). Non-surgical treatment of mild to moderate peri-implantitis with an oscillating chitosan brush or a titanium curette—12-month follow-up of a multicenter randomized clinical trial. Clinical Oral Implants Research. ISSN 0905-7161. doi: 10.1111/clr.14078. Full text in Research Archive
• Khan, Sadia Nazir; Koldsland, Odd Carsten; Roos-Jansåker, Ann-Marie; Wohlfahrt, Johan Caspar; Verket, Anders & Mdala, Ibrahimu [Show all 9 contributors for this article] (2022). Non-surgical treatment of mild to moderate peri-implantitis using an oscillating chitosan brush or a titanium curette—A randomized multicentre controlled clinical trial. Clinical Oral Implants Research. ISSN 0905-7161. doi: 10.1111/clr.14007. Full text in Research Archive Show summary

  Objectives This prospective, parallel-group, examiner-blinded, multicentre, randomized, controlled clinical trial aimed to assess the efficacy of an oscillating chitosan brush (OCB) versus titanium curettes (TC) on clinical parameters in the non-surgical treatment of peri-implantitis. Material and Methods In five dental specialist clinics, 39 patients with one implant with mild to moderate peri-implantitis, defined as 2–4 mm radiographic reduced bone level, bleeding index (BI) ≥ 2, and probing pocket depth (PPD) ≥ 4 mm were randomly allocated to test and control groups, receiving OCB or TC debridement, respectively. Treatment was performed at baseline and three months. PPD, BI, and Plaque index (PI) were measured at six sites per implant and recorded by five blinded examiners at baseline, one, three, and six month(s). Pus was recorded as present/not present. Changes in PPD and BI were compared between groups and analysed using multilevel partial ordinal and linear regression. Results Thirty-eight patients completed the study. Both groups showed significant reductions in PPD and BI at six months compared with baseline (p < .05). There was no statistically significant difference in PPD and BI changes between the groups. Eradication of peri-implant disease as defined was observed in 9.5% of cases in the OCB group and 5.9% in the TC group. Conclusions Within the limitations of this six-month multicentre clinical trial, non-surgical treatment of peri-implantitis with OCB and TC showed no difference between the interventions. Eradication of disease was not predictable for any of the groups.

• Thieu, Minh Khai Le; Homayouni, Amin; Hæren, Lena Ringsby; Tiainen, Hanna; Verket, Anders & Ellingsen, Jan Eirik [Show all 13 contributors for this article] (2021). Impact of simultaneous placement of implant and block bone graft substitute: an in vivo peri-implant defect model. Biomaterials Research. ISSN 1226-4601. 25(43). doi: 10.1186/s40824-021-00245-3. Full text in Research Archive Show summary

  Background Insufficient bone volume around an implant is a common obstacle when dental implant treatment is considered. Limited vertical or horizontal bone dimensions may lead to exposed implant threads following placement or a gap between the bone and implant. This is often addressed by bone augmentation procedures prior to or at the time of implant placement. This study evaluated bone healing when a synthetic TiO2 block scaffold was placed in circumferential peri-implant defects with buccal fenestrations. Methods The mandibular premolars were extracted and the alveolar bone left to heal for 4 weeks prior to implant placement in six minipigs. Two cylindrical defects were created in each hemi-mandible and were subsequent to implant placement allocated to treatment with either TiO2 scaffold or sham in a split mouth design. After 12 weeks of healing time, the samples were harvested. Microcomputed tomography (MicroCT) was used to investigate defect fill and integrity of the block scaffold. Distances from implant to bone in vertical and horizontal directions, percentage of bone to implant contact and defect fill were analysed by histology. Results MicroCT analysis demonstrated no differences between the groups for defect fill. Three of twelve scaffolds were partly fractured. At the buccal sites, histomorphometric analysis demonstrated higher bone fraction, higher percentage bone to implant contact and shorter distance from implant top to bone 0.5 mm lateral to implant surface in sham group as compared to the TiO2 group. Conclusions This study demonstrated less bone formation with the use of TiO2 scaffold block in combination with implant placement in cylindrical defects with buccal bone fenestrations, as compared to sham sites.

• Hussain, Badra; Karaca, Ebru Ozkan; Kuru, Bahar Eren; Gursoy, Hare; Haugen, Håvard Jostein & Wohlfahrt, Johan Caspar (2021). Treatment of residual pockets using an oscillating chitosan device versus regular curettes alone—a randomized, feasibility parallel-arm clinical trial. Journal of Periodontology. ISSN 0022-3492. doi: 10.1002/JPER.21-0496. Full text in Research Archive Show summary

  Background A brush made of chitosan has shown to be an effective and harmless device for non-surgical treatment of mild to moderate peri-implantitis. To date, no study has evaluated the use of a chitosan brush in the non-surgical treatment of residual pockets in periodontal treatment. Methods Seventy-eight patients with periodontitis were included in this multicenter, randomized, examiner-blind clinical trial of 6 months duration. Patients with residual probing pocket depth (PPD) of ≥5 mm and ≤7 mm following previous active periodontal treatment were included. Patients were assigned either subgingival treatment with curettes (control) or an oscillating chitosan brush (test). Changes in bleeding on probing (BoP) and PPD between baseline and terminal evaluation at 6 months were evaluated. Results A significant reduction in both PPD and BoP was seen within both groups. There was no significant difference in BoP between test and control groups after 6 months, but the reduction in PPD was significantly improved in the test group (P ≤ 0.01). The combined outcome of no BOP and PPD ≤4 mm was significantly better in the test group (P ≤ 0.01). No adverse reactions were seen. Conclusion Treatment of residual periodontal pockets (PPD = 5 to 7 mm) with a chitosan brush disclosed equal or better clinical results as compared to regular curettes. This study supports that a chitosan brush can be used for subgingival biofilm removal and soft tissue curretage in the treatment of periodontitis.

• Wohlfahrt, Johan Caspar; Aass, Anne Merete & Koldsland, Odd Carsten (2019). Treatment of peri-implant mucositis with a chitosan brush? A pilot randomized clinical trial. International Journal of Dental Hygiene. ISSN 1601-5029. p. 1–7. doi: 10.1111/idh.12381. Full text in Research Archive
• Koldsland, Odd Carsten; Wohlfahrt, Johan Caspar & Aass, Anne Merete (2018). Surgical treatment of peri-implantitis: Prognostic indicators of short-term results. Journal of Clinical Periodontology. ISSN 0303-6979. 45(1), p. 100–113. doi: 10.1111/jcpe.12816. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter; Tiainen, Hanna; Rønold, Hans Jacob & Wohlfahrt, Johan Caspar (2018). Impact of particulate deproteinized bovine bone mineral and porous titanium granules on early stability and osseointegration of dental implants in narrow marginal circumferential bone defects. International Journal of Oral & Maxillofacial Surgery. ISSN 0901-5027. 47(8), p. 1086–1094. doi: 10.1016/j.ijom.2018.02.007. Full text in Research Archive Show summary

  The use of two particulate bone graft substitute materials in experimental narrow marginal peri-implant bone defects was investigated with respect to early bone healing and implant stability. Porous titanium granules, oxidized white porous titanium granules (WPTG), and demineralized bovine bone mineral (DBBM) were characterized in vitro, after which the two latter materials were tested in experimental peri-implant bone defects in six minipigs, with empty defects as control. After mandibular premolar extraction, the top 5 mm of the alveoli were widened to 6 mm in diameter, followed by the placement of six implants, three on each side, in each pig. Six weeks of healing was allowed. The WPTG showed better mechanical properties. No significant differences in resonance frequency analysis were found directly after compacting or healing, and similar quantities of defect bone formation were observed on micro-computed tomography for all groups. Histomorphometric analysis demonstrated a more coronal bone-to-implant contact in the DBBM group, which also displayed more defect bone fill as compared to the WPTG group. The better mechanical properties observed for WPTG appear of negligible relevance for the early stability and osseointegration of implants.

• Andersen, Heidi; Aass, Anne Merete & Wohlfahrt, Johan Caspar (2017). Porous titanium granules in the treatment of peri-implant osseous defects-a 7-year follow-up study. International Journal of Implant Dentistry. p. 1–7. doi: 10.1186/s40729-017-0106-2. Full text in Research Archive Show summary

  Background A great number of different treatment protocols for peri-implantitis have been suggested but there is no consensus regarding the most effective intervention. The aim of the present study was to evaluate the long-term clinical and radiographic results from a study on peri-implant osseous defect reconstruction. Patients having participated in a randomized clinical study 7 years earlier were invited for a re-examination. The treatment procedures included open flap debridement (OFD) with or without defect reconstruction with porous titanium granules (PTGs). Clinical parameters (probing pocket depth and bleeding on probing) and radiographic measurements were registered. Findings Of the original 32 patients, 12 patients with 12 implants were finally examined after 7 years (7.3 years [6.7–8]). Patients had been maintained one to two times yearly. The PTG group showed a mean probing pocket depth of 4.3 mm ± 2.4 compared with 3.5 mm ± 1.2 in the OFD group, at the deepest site. The change between the 12 months and the 7-year examination was similar in both groups. Five of the test implants and five of the control implants had at least one site with positive bleeding on probing score. The mean radiographic defect depth change as compared to 12 months was an increase of 1.9 mm ± 2.0 in the PTG group and a mean radiographic defect depth increase of 1.3 mm ± 1.4 in the OFD group. Due to the small number of patients, a statistical analysis was not performed, but the results indicated a minimal difference in osseous defect depth as compared with baseline and between groups. No PTG exposed to the oral cavity was observed, but the graft particles were seemingly scattered in the peri-implant soft tissue. Conclusions This long-term follow-up of surgical treatment of peri-implant osseous defects showed unpredictable results.

• Wohlfahrt, Johan Caspar; Evensen, Bjørnar; Zeza, B; Jansson, Harald; Pilloni, A & Roos-Jansåker, AM [Show all 10 contributors for this article] (2017). A novel non-surgical method for mild peri-implantitis- a multicenter consecutive case series. International Journal of Implant Dentistry. p. 1–8. doi: 10.1186/s40729-017-0098-y. Full text in Research Archive Show summary

  Aim The aim of the present study was to evaluate the effect on peri-implant mucosal inflammation from the use of a novel instrument made of chitosan in the non-surgical treatment of mild peri-implantitis across several clinical centers. Materials and methods In this 6-month multicenter prospective consecutive case series performed in six different periodontal specialist clinics, 63 implants in 63 patients were finally included. The subjects had mild peri-implantitis defined as radiographic bone loss of 1–2 mm, pocket probing depth (PPD) ≥4 mm and a positive bleeding on probing (mBoP) score. The patients were clinically examined at baseline and after 2, 4, 12 and 24 weeks, and radiographs were taken at baseline and at 3 and 6 months. Treatment of the implants with the chitosan brush seated in an oscillating dental drill piece was performed at baseline and at 3 months. Reductions in the clinical parameters (PPD and mBoP) were compared between baseline and the later examination time points. Results Significant reductions in both PPD and mBoP were observed at all time points compared with the baseline clinical measurements (p < 0.001). The mean PPD and mBoP at baseline were 5.15 mm (4.97; 5.32) and 1.86 (1.78; 1.93), respectively, whereas the mean PPD and mBoP at 6 months were 4.0 mm (3.91; 4.19) and 0.64 (0.54; 0.75), respectively. Stable reductions in PPD and mBoP were evident up to 6 months after the initial treatment and 3 months after the second treatment. All 63 implants were reported to have stable radiographic levels of osseous support. Conclusions This case series demonstrated that an oscillating chitosan brush is safe to use and seems to have merits in the non-surgical treatment of dental implants with mild peri-implantitis. To measure the effectiveness of the method, a multicenter randomized clinical trial needs to be undertaken.

• Zeza, Blerina; Wohlfahrt, Johan Caspar & Pilloni, Andrea (2017). Chitosan brush for professional removal of plaque in mild peri-implantitis. Minerva Stomatologica. ISSN 0026-4970. 66(4), p. 163–168. doi: 10.23736/S0026-4970.17.04040-7. Full text in Research Archive
• Verket, Anders; Müller, Benjamin; Wohlfahrt, Johan Caspar; Lyngstadaas, Ståle Petter; Ellingsen, Jan Eirik & Haugen, Håvard Jostein [Show all 7 contributors for this article] (2016). TiO2 scaffolds in peri-implant dehiscence defects: an experimental pilot study. Clinical Oral Implants Research. ISSN 0905-7161. 27(10), p. 1200–1206. doi: 10.1111/clr.12725. Full text in Research Archive
• Villa, Oscar; Wohlfahrt, Johan Caspar; Koldsland, Odd Carsten; Brookes, Steven J; Lyngstadaas, Ståle Petter & Aass, Anne Merete [Show all 7 contributors for this article] (2016). EMD in periodontal regenerative surgery modulates cytokine profiles: A randomised controlled clinical trial. Scientific Reports. 6, p. 1–9. doi: 10.1038/srep23060. Full text in Research Archive Show summary

  The enamel matrix derivative (EMD) contains hundreds of peptides in different levels of proteolytic processing that may provide a range of biological effects of importance in wound healing. The aim of the present study was to compare the effect of EMD and its fractions on the cytokine profiles from human gingival fibroblasts in vitro and in gingival crevicular fluid (GCF) in a randomized controlled split-mouth clinical study (n = 12). Levels of cytokines in cell culture medium and in GCF were measured by Luminex over a 2-week period. In the clinical study, levels of pro-inflammatory cytokines and chemokines were increased, whereas the levels of transforming growth factor-α (TGF-α) and platelet-derived growth factor-BB (PDGF-BB) were reduced. The in vitro study showed that EMD and its high and low molecular weight fractions reduced the secretion of pro-inflammatory cytokines and chemokines compared to untreated cells. EMD had an effect on levels of cytokines related to fibroplasia, angiogenesis, inflammation and chemotaxis both in vitro and in vivo, however, the anti-inflammatory effect induced by EMD observed in the in vitro study could not be confirmed clinically.

• Villa, Oscar; Wohlfahrt, Johan Caspar; Mdala, Ibrahimu; Petzold, Christiane; Reseland, Janne Elin & Snead, Malcolm L. [Show all 7 contributors for this article] (2015). Proline-rich peptide mimic effects of EMD in rat oral mucosal incisional wound healing. Journal of Periodontology. ISSN 0022-3492. 86(12), p. 1386–1395. doi: 10.1902/jop.2015.150207. Full text in Research Archive
• Villa, Oscar; Lyngstadaas, Ståle Petter; Monjo, Marta; Satué, María; Rønold, Hans Jacob & Petzold, Christiane [Show all 7 contributors for this article] (2015). Suture materials affect peri-implant bone healing and implant osseointegration. Journal of Oral Science. ISSN 1343-4934. 57(3), p. 219–227. doi: 10.2334/josnusd.57.219. Full text in Research Archive
• Lutnæs, Odd Bjørn; Wohlfahrt, Johan Caspar; Aass, Anne Merete & Koldsland, Odd Carsten (2015). Tilleggseffekten av fotodynamisk terapi ved ikke-kirurgisk periodontal behandling. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 125(8), p. 692–697. Full text in Research Archive
• Andersen, Jostein; Koldsland, Odd Carsten; Aass, Anne Merete & Wohlfahrt, Johan Caspar (2014). Langtidsresultater etter kirurgisk korrigering av bukkale gingivale retraksjoner : en litteraturstudie. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 124(10), p. 810–817. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob & Wohlfahrt, Johan Caspar (2014). Osseointegration of dental implants in extraction sockets preserved with porous titanium granules - an experimental study. Clinical Oral Implants Research. ISSN 0905-7161. 25(2), p. E100–E108. doi: 10.1111/clr.12070. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Granfeldt, Finn; Lyngstadaas, Ståle Petter & Reseland, Janne Elin (2014). Sulcus fluid bone marker levels and the outcome of surgical treatment of peri-implantitis. Journal of Clinical Periodontology. ISSN 0303-6979. 41(4), p. 424–431. doi: 10.1111/jcpe.12229. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter; Rasmusson, Lars; Haanæs, Hans R; Wallstrøm, M. & Wall, Gert [Show all 7 contributors for this article] (2013). Maxillary Sinus Augmentation with Porous Titanium Granules: A Microcomputed Tomography and Histologic Evaluation of Human Biopsy Specimens. International Journal of Oral & Maxillofacial Implants. ISSN 0882-2786. 28(3), p. 721–728. doi: 10.11607/jomi.2853. Full text in Research Archive Show summary

  PURPOSE: The aim of this study was to assess bone ingrowth into porous titanium granules used for maxillary sinus augmentation. MATERIALS AND METHODS: Eighteen biopsy specimens from 17 patients participating in a clinical trial on sinus augmentation using porous titanium granules (PTG) were received in the laboratory. The specimens (trephine cores of 4.5 mm) were obtained 6 months after PTG placement. After being embedded in methacrylate, the samples were scanned in a microcomputed tomography (micro-CT) scanner. Specimens were then cut along the long axis and central slices were ground to 70 μm before staining with hematoxylin and eosin. RESULTS: The micro-CT analysis demonstrated an average bone fill of 19% (standard deviation [SD] 5.8%), whereas the graft material occupied 22.7% (SD 4.7%). The volume of newly formed bone decreased with the distance from the residual bone of the sinus floor. Two-dimensional histomorphometric analysis demonstrated a mean area of new bone of 16.1% (SD 9.4%). The PTG alone occupied 25.9% of the total mean area (SD 6.1%). The newly formed bone consisted mainly of woven bone growing in close contact with the granules and bridging the intergranular space. The remaining area was occupied predominantly by nonmineralized connective tissue. There were no signs of inflammation in any of the biopsy specimens. CONCLUSIONS: After 6 months, new bone had formed at a similar rate and quality as has been reported for other well-recognized bone graft substitutes. The new bone formed in close contact with the PTG, suggesting that the material is osteoconductive.

• Haugen, Håvard Jostein; Cabrer, Marta Monjo; Rubert, Marina; Verket, Anders; Lyngstadaas, Ståle Petter & Ellingsen, Jan Eirik [Show all 8 contributors for this article] (2013). Porous Ceramic Titanium Dioxide Scaffolds Promote Bone Formation in Rabbit Peri-Implant Cortical Defect Model. Acta Biomaterialia. ISSN 1742-7061. 9(2), p. 5390–5399. doi: 10.1016/j.actbio.2012.09.009. Full text in Research Archive Show summary

  Titanium oxide (TiO2) scaffolds have previously been reported to exhibit very low mechanical strength. However, we have been able to produce a scaffold that features a high interconnectivity, a porosity of 91% and a compressive strength above 1.2 MPa. This study analysed the in vivo performance of the porous TiO2 scaffolds in a peri-implant cortical defect model in the rabbit. After 8 weeks of healing, morphological microCT analyses of the defects treated with the TiO2 scaffolds had significantly higher bone volume, bone surface and bone surface to volume ratio when compared to sham, both in the cortical and bone marrow compartment. No adverse effects, i.e. tissue necrosis or inflammation as measured by LDH activity and real-time RT-PCR analysis were observed. Moreover, the scaffold did not hinder bone growth onto the adjacent cortical titanium implant. Histology clearly demonstrated new bone formation in the cortical sections of the defects and presence of newly formed bone in close proximity to the scaffold surface and the surface of the adjacent Ti implant. Bone to material contact between the newly formed bone and the scaffold was observed in the histological sections. Islets of new bone were also present in the marrow compartment albeit in scarce amounts. In conclusion, the present investigation demonstrates that TiO2 scaffolds osseointegrate well and is a suitable scaffold for peri-implant bone healing and growth. --------------------------------------------------------------------------------

• Henderson, Elisabet; Schneider, Sigurd; Petersen, Fernanda Cristina; Haugen, Håvard Jostein; Wohlfahrt, Johan Caspar & Ekstrand, Karl [Show all 7 contributors for this article] (2013). Chemical debridement of contaminated titanium surfaces: An in vitro study. Acta Odontologica Scandinavica. ISSN 0001-6357. 71(3-4), p. 957–964. doi: 10.3109/00016357.2012.734423. Full text in Research Archive Show summary

  Abstract Objective. To compare the efficacy of different chemical solutions when used for chemical debridement of biofilm contaminated titanium surfaces in an in-vitro experimental study. Materials and methods. Commercially pure titanium discs with a diameter of 6.2 mm and height of 2 mm, mirror-polished with a measured surface amplitude value S(A) = 0.037 μm ± 0.009 were used as test-surfaces. A biofilm was simulated with multi-layers of Staphylococcus epidermidis ATCC359844 covering the entire titanium surface. The chemical agents tested were: 3% H(2)O(2), 0.2% Chlorhexidine, 24% EDTA-gel, 3% H(2)O(2) mixed with 1.6 g/L TiO(2) and sterile saline solution. The decontamination effect was evaluated by optical density analysis using spectrophotometry and with scanning electron microscopy (SEM) images of the remaining biofilm. Results. The suspensions of 3% H(2)O(2) and 1.6 g/L TiO(2) or 3% H(2)O(2) alone were the most effective in removing S. epidermidis biofilms (p < 0.05), whereas 0.2% chlorhexidine or 24% EDTA gel had no significant effects. SEM images of the remaining biofilms supported the quantitative results indicating the higher efficacy of 3% H(2)O(2) and 1.6 g/L TiO(2) or 3% H(2)O(2) alone. It also revealed that EDTA, despite a non-significant effect on reducing the amount of established biofilms, was able to alter the biofilm architecture, as demonstrated by increased interspaced regions. Conclusions. In this in vitro study the decontamination potential of a suspension of 3% H(2)O(2) and 1.6 g/L TiO(2) or 3% H(2)O(2) alone were encouraging. Whether such procedures would have a similar effect in vivo remains to be determined.

• Wohlfahrt, Johan Caspar; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob; Saxegaard, Erik; Ellingsen, Jan Eirik & Karlsson, Stig [Show all 7 contributors for this article] (2012). Porous Titanium Granules in the Surgical Treatment of Peri-Implant Osseous Defects: A Randomized Clinical Trial. International Journal of Oral & Maxillofacial Implants. ISSN 0882-2786. 27(2), p. 401–410. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2012). Bone formation in TiO2 bone scaffolds in extraction sockets of minipigs. Acta Biomaterialia. ISSN 1742-7061. 8(6), p. 2384–2391. doi: 10.1016/j.actbio.2012.02.020. Full text in Research Archive Show summary

  The osteoconductive capacity of TiO2 scaffolds was investigated by analysing the bone ingrowth into the scaffold structure following their placement into surgically modified extraction sockets in Gottingen minipigs. Non-critical size defects were used in order to ensure sufficient bone regeneration for the evaluation of bone ingrowth to the porous scaffold structure, and sham sites were used as positive control. Micro-CT analysis revealed 73.6 ± 11.1 % of the available scaffold pore space to be occupied by newly formed bone tissue, and the volumetric bone mineral density of the regenerated bone was comparable to that of the native cortical bone. Furthermore, histological evidence for vascularisation and presence of bone lamellae surrounding some of the blood vessels was observed also within the inner regions of the scaffold, indicating that the highly interconnected pore structure of the TiO2 scaffolds supports unobstructed formation of viable bone tissue within the entire scaffold structure. In addition, bone tissue was found in direct contact with 50.0 ± 21.5 % of the TiO2 struts demonstrating the good biocompatibility and osteoconductivity of the scaffold material. Keywords Bone scaffold; Titanium dioxide; Pore structure; Bone ingrowth; Implant integration Corresponding author. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

• Wohlfahrt, Johan Caspar; Lyngstadaas, Ståle Petter; Heijl, Lars & Aass, Anne Merete (2012). Porous Titanium Granules in the Treatment of Mandibular Class II Furcation Defects: A Consecutive Case Series. Journal of Periodontology. ISSN 0022-3492. 83(1), p. 61–69. doi: 10.1902/jop.2011.100769. Full text in Research Archive
• Bashara, Haitham; Wohlfahrt, Johan Caspar; Polyzois, Ioannis; Lyngstadaas, Ståle Petter; Renvert, Stefan & Claffey, Noel (2012). The effect of permanent grafting materials on the preservation of the buccal bone plate after tooth extraction: an experimental study in the dog. Clinical Oral Implants Research. ISSN 0905-7161. 23(8), p. 911–917. doi: 10.1111/j.1600-0501.2011.02240.x. Full text in Research Archive
• Tiainen, Hanna; Verket, Anders; Haugen, Håvard Jostein; Lyngstadaas, Ståle Petter & Wohlfahrt, Johan Caspar (2012). Dimensional ridge preservation with a novel highly porous TiO2 scaffold: an experimental study in minipigs. International Journal of Biomaterials. ISSN 1687-8787. doi: 10.1155/2012/851264. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Rønold, Hans Jacob; Heijl, Lars; Haugen, Håvard Jostein & Lyngstadaas, Ståle Petter (2012). Microcomputed Tomographic and Histologic Analysis of Animal Experimental Degree II Furcation Defects Treated With Porous Titanium Granules or Deproteinized Bovine Bone. Journal of Periodontology. ISSN 0022-3492. 83(2), p. 211–221. doi: 10.1902/jop.2011.110128. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob & Wohlfahrt, Johan Caspar (2012). Microcomputed Tomography and Histological Analysis of a Maxillary Implant Retrieved 19 Months After Placement and Indirect Sinus Augmentation With Biphasic Calcium Phosphate: A Case Report. Clinical Advances in Periodontics. ISSN 2573-8046. 4(1), p. 38–42. doi: 10.1902/cap.2012.120075. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter (2011). Micro CT and human histological analysis of a peri-implant osseous defect grafted with porous titanium granules: a case report. International Journal of Oral & Maxillofacial Implants. ISSN 0882-2786. 26(1), p. 9–14. Full text in Research Archive
• Monjo, Marta; Rubert, Marina; Wohlfahrt, Johan Caspar; Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2010). In Vivo Performance Of Absorbable Collagen Sponges With Rosuvastatin In Critical-Size Cortical Bone Defects. Acta Biomaterialia. ISSN 1742-7061. 6(4), p. 1405–1412. doi: 10.1016/j.actbio.2009.09.027. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Monjo, Marta; Rønold, Hans Jacob; Aass, Anne Merete; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2010). Porous titanium granules promote bone healing and growth in rabbit tibia peri-implant osseous defects. Clinical Oral Implants Research. ISSN 0905-7161. 21(2), p. 165–173. doi: 10.1111/j.1600-0501.2009.01813.x. Full text in Research Archive
• Lyngstadaas, Ståle Petter; Wohlfahrt, Johan Caspar; Brookes, SJ; Paine, ML; Snead, Malcolm L. & Reseland, Janne Elin (2009). Enamel matrix proteins: old molecules for new applications. Orthodontics & craniofacial research. ISSN 1601-6335. 12(3), p. 243–253. Full text in Research Archive
• Lyngstadaas, Ståle Petter; Wohlfahrt, Johan Caspar; Brooks, Steve; Paine, M.L.; Snead, M.L. & Reseland, Janne Elin (2009). Enamel matrix proteins; old molecules for new applications. Orthodontics & craniofacial research. ISSN 1601-6335. 12(3), p. 243–253. doi: 10.1111/j.1601-6343.2009.01459.x. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Wu, T; Hodges, JS; Hinrichs, JE & Michalowicz, BS (2006). No association between selected candidate gene polymorphisms and severe chronic periodontitis. Journal of Periodontology. ISSN 0022-3492. 77(3), p. 426–436. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2003). Elevation of the maxillary sinus for placement of endosseous dental implants. Northwest dent. ISSN 0029-2915. 82(3), p. 34–36. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Ternesten, A; Sahlin, P; Islam, Q & Stenman, G (1997). Cytogenetic and fluorescence in situ hybridization analyses of a microcystic adnexal carcinoma with del(6)(q23q25). Cancer Genetics and Cytogenetics. ISSN 0165-4608. 15(98), p. 106–110. Full text in Research Archive

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• Pihlstrom, Bruce L; Hodges, James S; Michalowicz, Bryan S.; Wohlfahrt, Johan Caspar & Garcia, Raul I (2018). Authors' response. The Journal of the American Dental Association (1939). ISSN 0002-8177. 149(9), p. 751–752. doi: 10.1016/j.adaj.2018.07.010. Full text in Research Archive
• Villa, Oscar; Wohlfahrt, Johan Caspar; Mdala, Ibrahimu; Petzold, Christiane; Reseland, Janne Elin & Snead, Malcolm L. [Show all 7 contributors for this article] (2015). Proline-rich peptides accelerate oral mucosal wound healing. Full text in Research Archive
• Wohlfahrt, Johan Caspar & Koldsland, Odd Carsten (2014). Peri-implantologi; hva vet vi, hva gjør vi og hva prøver vi å finne ut av. Full text in Research Archive
• Wohlfahrt, Johan Caspar & Klepp, Morten (2014). Periodonti og peri-implantologi fra et vitenskapelig og klinisk ståsted. Full text in Research Archive
• Wohlfahrt, Johan Caspar & Koldsland, Odd Carsten (2014). Pasienten har fått sitt implantat-hva nå? Full text in Research Archive
• Wohlfahrt, Johan Caspar & Koldsland, Odd Carsten (2014). Peri-Implantit -Vad vet vi, vad gör vi, vad forskar vi på? Full text in Research Archive
• Wohlfahrt, Johan Caspar (2014). The patient with the hopeless tooth versus the patient with peri-implantitis - What road do we want to go now? Full text in Research Archive
• Wohlfahrt, Johan Caspar; Lyngstadaas, Ståle Petter; Aass, Anne Merete & Koldsland, Odd Carsten (2014). Implant Maintenance with a Chitosan Brush –A Randomized Clinical Trial. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2014). Diagnosis and treatment of peri-implant disease. Full text in Research Archive
• Skjerven, Henrik; Herlofson, Bente Brokstad; Wohlfahrt, Johan Caspar; Rønold, Hans Jacob & Ellingsen, Jan Eirik (2014). Evaluation of the Precision of implant placement using stereolithographic guides. Full text in Research Archive
• Tiainen, Hanna; Wiedmer, David; Wohlfahrt, Johan Caspar; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2013). Highly porous ceramic titanium dioxide scaffolds for bone repair. Full text in Research Archive
• Villa, Oscar; Lyngstadaas, Ståle Petter; Monjo, Marta; Rønold, Hans Jacob; Petzold, Christiane & Wohlfahrt, Johan Caspar (2013). The influence of suture remnants on peri-implant bone healing - A pilot animal experimental study. Full text in Research Archive Show summary

  Background: Suture remnants may potentially induce an inflammation and influence peri-implant osseous healing. It might thus be preferable to use a resorbable suture material in order to avoid soft and hard tissue complications. Aim: To evaluate the influence of remnants of suture filaments on osseointegration in a rabbit tibial model. Material and methods: In this pilot animal experimental study calibrated defects were prepared in the tibia of 5 chinchilla rabbits. Four sites were prepared in each animal and randomized to one of the three groups. Test filaments of nylon and chitosan were placed at the prepared implant sites before implant placement. A sham site was used as control. A coin-shaped machined titanium implant covered with a teflon cap and a preshaped maxillofacial bone plate were seated over the prepared cortical bone. After a healing period of 4 weeks, rabbits were euthanized and the tibial bone with the implants was exposed and removed. The implants were subjected to a pull-out test procedure. Wound fluid was collected with filter papers for the analyses of lactate dehydrogenase activity, alkaline phosphatase activity and total protein. Total-RNA was isolated from the peri-implant bone tissue. Real time PCR was performed for the following target genes: vacuolar type proton ATPase, insulin like growth factor-1, bone morphogenetic protein-2 , collagen-1, interleukin-10, interleukin-6, osteocalcin, calcitonin receptor, tartrate-resistant acid phosphatase and tumor necrosis factor-α. A one-way analysis of variance was used to detect differences across groups with the significance level set at 0.05. Results: When comparing the data across the three groups no statistically significant differences were found. There was, however, a trend towards a reduced pull-out force for the nylon group (Nylon: 23.0 ± 12.8; Chitosan: 33.9 ± 11.3; Sham 33.6 ± 24.0). Similarly, the resorption bone marker vacuolar type proton ATPase was increased in the nylon group compared to the sham and chitosan groups. The chitosan group showed lower ALP activity and lower expression of osteocalcin compared to the nylon group. Conclusions and clinical implications: In this closed surgical model, peri-implant bone healing was only marginally affected by the different materials tested. There was, however, a tendency toward better osseointegration and less expression of bone resorption markers in the sham and chitosan groups as compared to the nylon group. The number of animals was low in this pilot study and further research is warranted to explore this issue. The influence of suture remnants on peri-implant bone healing - A pilot animal experimental study.

• Tiainen, Hanna; Wiedmer, David; Wohlfahrt, Johan Caspar; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2013). Highly porous ceramic TiO2 scaffolds for bone repair. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2012). Bone formation in TiO2 bone scaffolds in extraction sockets of minipigs. Bone. ISSN 8756-3282. 50, p. S115–S115. doi: 10.1016/j.bone.2012.02.354. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2012). Highly porous TiO2 scaffolds for bone repair. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter; Rasmusson, Lars & Wohlfahrt, Johan Caspar (2012). Sinus Augmentation with Porous Titanium Granules- MicroCT and Histological Analysis. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Grandfeldt, F.; Lyngstadaas, Ståle Petter & Reseland, Janne Elin (2012). Change in bone resorption markers in pen-implant sulcus fluid after surgical treatment of peri-implantitis. Bone. ISSN 8756-3282. 50, p. S116–S116. doi: 10.1016/j.bone.2012.02.358. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2012). Bone formation in TiO2 bone scaffolds in extraction sockets of minipigs. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2012). Highly porous TiO2 scaffolds show excellent bone ingrowth in vivo. Full text in Research Archive
• Haugen, Håvard Jostein; Cabrer, Marta Monjo; Lyngstadaas, Ståle Petter & Wohlfahrt, Johan Caspar (2012). Ultra-Porous Ceramic Titanium Dioxide Bone grafts Promote Bone Healing in Rabbit Peri-Implant Cortical Defect Model. Full text in Research Archive
• Schneider, Sigurd; Henderson, Elisabet; Wohlfahrt, Johan Caspar; Taxt-Lamolle, Sebastien Francis Michel; Gustumhaugen, Eva & Petersen, Fernanda Cristina [Show all 9 contributors for this article] (2011). A nano chemical debridement solution shows high efficiency on contaminated titanium surface. European Cells and Materials. 21, p. 19–19. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter & Wohlfahrt, Johan Caspar (2011). Augmentation of the Maxillary Sinus Floor Using Porous Titanium Granules. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2011). Assessment of bone ingrowth into porous TiO2 bone scaffold. Full text in Research Archive
• Verket, Anders; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob & Wohlfahrt, Johan Caspar (2011). Implants inserted in Extraction Sockets Grafted with Porous Titanium Granules. Full text in Research Archive
• Tiainen, Hanna; Wohlfahrt, Johan Caspar; Verket, Anders; Ellingsen, Jan Eirik; Lyngstadaas, Ståle Petter & Haugen, Håvard Jostein (2011). Ultra-porous titanium dioxide scaffolds for bone repair. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Rønold, Hans Jacob; Karlsson, Stig; Ellingsen, Jan Eirik & Saxegaard, Erik (2010). Porous titanium granules in the surgical treatment of peri-implant osseous defects - a randomized clinical trial. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Rønold, Hans Jacob; Heijl, L; Haugen, Håvard Jostein; Aass, Anne Merete & Lyngstadaas, Ståle Petter (2010). Porous titanium granules in degree II furcation defects - an animal experimental study. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Rønold, Hans Jacob; Karlsson, Stig; Ellingsen, Jan Eirik & Saxegaard, Erik [Show all 7 contributors for this article] (2009). Porous Titanium Granules in the Surgical Treatment of Peri-Implant Osseous Defects – A Randomized Clinical Study. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Rønold, Hans Jacob; Aass, Anne Merete; Heijl, Lars & Lyngstadaas, Ståle Petter (2009). Porous titanium granules in degree II furcation defects- an animal experimental study. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2009). Regenerasjons behandling med porøse titan granula. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2009). Kirurgisk behandling av peri-implantat bein defekter- forsking ved Universitetet i Oslo. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2008). Surgical treatment of peri-implant osseous defects-Ongoing studies at the University of Oslo. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2008). Peri-Implantit. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Aass, Anne Merete; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter (2008). Titanium Granules for Treatment of Periimplantitis Osseous Defects - A Pilot Randomized Clinical Study with Human Histology. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Rønold, Hans Jacob; Aass, Anne Merete; Monjo, Marta & Lyngstadaas, Ståle Petter (2008). Porous Titanium Granules in Rabbit Tibia Critical Size Osseous Defects. Full text in Research Archive
• Wohlfahrt, Johan Caspar; Reseland, Janne Elin & Lyngstadaas, Ståle Petter (2007). Vevsregenerasjon med amelogenin-klinisk erfaring of fremtidsperspektiver. Odontologi. ISSN 0105-0141. p. 113–126. Full text in Research Archive
• Samuelsson, Roy; Haanæs, Hans R & Wohlfahrt, Johan Caspar (2007). Når beinforholdene er inadekvate ved implantatbehandling. NDD-oppriktig dentalt. p. 16–19. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2007). Contemporary Periodontology and Peri-implantology-Overview in brief and own research at the University of Oslo. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2007). Peri-implantitis- Does it really exist? Full text in Research Archive
• Wohlfahrt, Johan Caspar (2007). Peri-Implantitt-Titangranulat for benregenerasjon. Full text in Research Archive
• Wohlfahrt, Johan Caspar (2012). On the use of titanium based materials as non-resorbable bone substitutes. Universitetet i Oslo. Full text in Research Archive

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