Hans Jacob Rønold

• Antich-Rosselló, Miquel; Forteza-Genestra, Maria Antònia; Rønold, Hans Jacob; Lyngstadaas, Ståle Petter; García-González, Mario & Permuy, María [Show all 10 contributors for this article] (2023). Platelet-derived extracellular vesicles formulated with hyaluronic acid gels for application at the bone-implant interface: An animal study. Journal of orthopaedic translation. ISSN 2214-0328. 40, p. 72–79. doi: 10.1016/j.jot.2023.05.009. Full text in Research Archive
• Sagen, Mina Aker; Vos, Linda; Dahl, Jon Einar & Rønold, Hans Jacob (2022). Shear bond strength of resin bonded zirconia and lithium disilicate - effect of surface treatment of ceramics and dentin. Biomaterial Investigations in Dentistry. 9(1), p. 10–19. doi: 10.1080/26415275.2022.2038177. Full text in Research Archive Show summary

  Introduction Materials and methods Results Discussion Acknowledgements Disclosure statement Additional information References Full Article Figures & data References Citations Metrics Licensing Reprints & Permissions View PDFView EPUB Abstract Objectives:The purpose of the study was to investigate the effect of ceramic surface pretreatment, effect of resin cement and dentin surface roughness on shear bond strength. Methodology: Zirconia rods (n = 140) were randomly assigned to air born particle abrasion with aluminum oxide (Al2O3) or hot etching with potassium hydrogen difluoride (KHF2). Lithium disilicate rods (LDS; n = 50) etched with hydrofluoric acid served as reference material. In Part 1 of the study, ceramic rods were cemented to bovine dentin using 5 dual-polymerizing resin cements (Variolink Esthetic, Multilink Automix (Ivoclar Vivadent), Duo-Link (BISCO Dental), Panavia F2.0 (Kuraray Dental), RelyX Unicem (3 M)). Shear bond strength was tested and fracture morphology determined. In Part 2 of the study, test groups with the highest frequency of adhesive fractures between cement and dentin were selected for further bond strength testing with different surface roughness of dentin; ground with P1200 or P80 silicon carbide paper. Dentin samples were fractured vertically to the cemented surface and the adherence between cement and dentin was studied. Results: The results of Part 1 showed that hot etching of zirconia significantly improved bond strength to Duo-Link cement. In Part 2, RelyX Unicem showed significantly higher bond strength to P1200 compared to P80 ground dentin. For Variolink Esthetic, bond strengths to P1200 and P80 ground dentin were similar. Adhesive fracture between cement and dentin dominated. Conclusions: A smooth dentin surface (P1200) improved bond strength to RelyX Unicem. Surface roughness was not important for Variolink Esthetic.

• Øilo, Marit; Haugli, Ketil; Rønold, Hans Jacob; Ulsund, Amanda H.; Ruud, Amund & Kvam, Ketil (2021). Pre-cementation procedures’ effect on dental zirconias with different yttria content. Dental Materials. ISSN 0109-5641. 37(9), p. 1425–1436. doi: 10.1016/j.dental.2021.07.001. Full text in Research Archive Show summary

  Objectve Several pre-cementation procedures have been advocated to enhance adhesion between zirconia and resin-based cement. There is, however, limited documentation on how these pre-treatments affect the strength of zirconia crowns as most tests are performed on discs or bars. The aim was to assess the effect of pre-cementation procedures on fracture mode, fracture strength and cement retention on zirconia. Methods Two dental zirconia materials with different yttria content were assessed (<4 and>5 mol%). Both discs (n = 45) and crown-shaped specimens (n = 30) of the two materials were pretreated with either air-abrasion or hot-etching with KHF2 and compared with untreated controls with regards to surface roughness, crystallography, wettability, cement adhesion and fracture strength. Results and Significance Air-abrasion improves adhesion and strength of zirconia with moderate yttria content (<4 mol%). Acid etching with heated KHF2 showed the best effect on strength and cement retention on zirconia with higher yttria content (>5 mol%). Application of KHF2 was, however, complicated on crown-shaped specimens. Pre-treatment and cementation protocols should be optimized for different dental zirconias to improve both strength and retention. Keywords Dental ceramics Luting agents Surface modification Fractography Zirconuim dioxide

• Sagen, Mina Aker; Dahl, Jon Einar; Matinlinna, Jukka Pekka; Tibballs, John Earl & Rønold, Hans Jacob (2021). The influence of the resin-based cement layer on ceramic-dentin bond strength. European Journal of Oral Sciences. ISSN 0909-8836. p. 1–9. doi: 10.1111/eos.12791. Full text in Research Archive Show summary

  The purpose of the study was to measure the cement thickness obtained when ceramic rods were luted to dentin and to analyze the relation between cement thickness and the previously published tensile bond strength of similar test specimens. In addition, the ISO standard 4049:2019 method was used to determine the film thickness of the used cements. Zirconia (n = 100) and lithium disilicate (n = 50) rods were cemented to bovine dentin using one of five different resin-based cements. The ceramic-dentin test specimens were cut into two slices and the cement thickness was measured using a scanning electron microscope and compared to the bond strength values of similar specimens already published. The mean cement thickness recorded for ceramic rods cemented to dentin was in the range 20–40 µm, which was larger than the cement film thickness found by the ISO method. The cement film thickness determined according to ISO standard methods did not concur with the results obtained when cementing ceramic rods to dentin. For cementing ceramic restorations, a cement thickness in the range 25–35 µm seems to be favorable for the bond strength.

• 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.

• Haugen, Håvard Jostein; Soltvedt, Brandon Michael; Nguyen, Peter Haitrieu; Rønold, Hans Jacob & Johnsen, Gaute Floer (2020). Discrepancy in alloy composition of imported and non-imported porcelain-fused-to-metal (PFM) crowns produced by Norwegian dental laboratories. Biomaterial Investigations in Dentistry. doi: 10.1080/26415275.2020.1724512. Full text in Research Archive Show summary

  Even though the use of full ceramic crowns have become a well-established practice in dental clinics compare to the last decade, the use of imported casted porcelain-fused-to-metal (PFMs) crowns is still prevalent. The use of imported PFMs is often economically driven; however, when dentists order PFMs, they do not have capabilities to examine its true alloy content. Therefore, we raise the questions whether cheaper imported PFMs have more discrepancies in alloy content compared to domestically produced PFMs? This study included 62 porcelain-fused-to-metal crowns: 41 produced in Norway and 21 imported. Their alloy-composition was determined non-destructively by EDX and SEM. Imported PFMs demonstrated larger deviations compared with non-imported PFMs. Significant deviation was found in key metallic elements in the different alloys (W, In, Pd, Ag). The detected deviations in key element such as Wolfram and Indium could influence the PFMs service time. These finding may be of international concern.

• Skjerven, Henrik; Olsen-Bergem, Heming; Rønold, Hans Jacob; Riis, Ulf Harald & Ellingsen, Jan Eirik (2019). Comparison of postoperative intraoral scan versus cone beam computerised tomography to measure accuracy of guided implant placement—A prospective clinical study. Clinical Oral Implants Research. ISSN 0905-7161. 30(6), p. 531–541. doi: 10.1111/clr.13438. Full text in Research Archive
• Sagen, Mina Aker; Kvam, Ketil; Ruyter, Ivar Eystein & Rønold, Hans Jacob (2019). Debonding mechanism of zirconia and lithium disilicate resin cemented to dentin. Biomaterial Investigations in Dentistry. 5(1), p. 22–29. doi: 10.1080/23337931.2018.1561188. Full text in Research Archive Show summary

  To evaluate debonding mechanism of zirconia and lithium disilicate cemented to dentin mimicking what could occur in a clinical setting. A null hypothesis of no difference in tensile bond strength between groups of zirconia and lithium disilicate cemented with resin cements was also tested. Zirconia rods (n = 100) were randomly assigned to two different surface treatment groups; air borne particle abrasion and hot etching by potassium hydrogen difluoride (KHF2). Lithium disilicate rods (n = 50) were surface etched by hydrofluoric acid (HF). Five different dual cure resin cements were used for cementing rods to bovine dentin. Ten rods of each test group were cemented with each cement. Test specimens were thermocycled before tensile bond strength testing. Fracture morphology was visualized by light microscope. Mean surface roughness (Sa value) was calculated for randomly selected rods. Cohesive fracture in cement was the most frequent observed fracture morphology. Combination of adhesive and cohesive fractures were second most common. Fracture characterized as an adhesive between rod and cement was not observed for KHF2 etched zirconia. Highest mean tensile bond strength was observed when cementing air borne particle abraded zirconia with Variolink Esthetic (Ivoclar Vivadent). All surface treatments resulted in Sa values that were significant different from each other. The number of cohesive cement fractures observed suggested that the cement was the weakest link in bonding of zirconia and lithium disilicate.

• Dahl, Bjørn Einar; Dahl, Jon Einar & Rønold, Hans Jacob (2018). Internal fit of three-unit fixed dental prostheses produced by computer-aided design/computer-aided manufacturing and the lost-wax metal casting technique assessed using the triple-scan protocol. European Journal of Oral Sciences. ISSN 0909-8836. 126(1), p. 66–73. doi: 10.1111/eos.12394. Full text in Research Archive Show summary

  Suboptimal adaptation of fixed dental prostheses (FDPs) can lead to technical and biological complications. It is unclear if the computer-aided design/computer-aided manufacturing (CAD/CAM) technique improves adaptation of FDPs compared with FDPs made using the lost-wax and metal casting technique. Three-unit FDPs were manufactured by CAD/CAM based on digital impression of a typodont model. The FDPs were made from one of five materials: pre-sintered zirconium dioxide; hot isostatic pressed zirconium dioxide; lithium disilicate glass-ceramic; milled cobalt-chromium; and laser-sintered cobalt-chromium. The FDPs made using the lost-wax and metal casting technique were used as reference. The fit of the FDPs was analysed using the triple-scan method. The fit was evaluated for both single abutments and three-unit FDPs. The average cement space varied between 50 μm and 300 μm. Insignificant differences in internal fit were observed between the CAD/CAM-manufactured FDPs, and none of the FPDs had cement spaces that were statistically significantly different from those of the reference FDP. For all FDPs, the cement space at a marginal band 0.5–1.0 mm from the preparation margin was less than 100 μm. The milled cobalt-chromium FDP had the closest fit. The cement space of FDPs produced using the CAD/CAM technique was similar to that of FDPs produced using the conventional lost-wax and metal casting technique.

• Córdoba, Alba; Manzanaro-Moreno, Nahuel; Colom, Carme; Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Monjo, Marta [Show all 7 contributors for this article] (2018). Quercitrin Nanocoated Implant Surfaces Reduce Osteoclast Activity In Vitro and In Vivo. International Journal of Molecular Sciences. ISSN 1661-6596. 19(11). doi: 10.3390/ijms19113319. Full text in Research Archive Show summary

  In this study, the effect on osteoclast activity in vitro and in vivo of titanium implants that were coated with quercitrin was evaluated. Titanium surfaces were covalently coated with the flavonoid quercitrin. The effect of the surfaces on osteoclastogenesis was first tested in vitro on RAW264.7 cells that were supplemented with receptor activator of nuclear factor kappa-B ligand (RANKL) to generate osteoclast-like cells by tartrate-resistant acid phosphatase (TRAP) inmunostaining after five days of culture, and by analysis of the mRNA expression levels of markers related to bone resorption after seven days of culture. A rabbit tibial model was used to evaluate the in vivo biological response to the implant surfaces after eight weeks of healing, analyzing the lactate dehydrogenase (LDH) and the alkaline phosphatase (ALP) activities in the wound fluid that were present at the implant interface and the peri-implant bone mRNA expression levels of several markers related to inflammation, bone resorption and osteoblast-osteoclast interaction. No differences between groups and control surfaces were found in the wound fluid analyses. Moreover, quercitrin implant surfaces significantly decreased the expression of osteoclast related genes in vitro (Trap, CalcR, Ctsk, H+ATPase, Mmp9) and in vivo (Ctsk, H+ATPase, Mmp9) as well as the expression of RankL in vivo. Moreover, quercitrin surfaces were not cytotoxic for the cells. Thus, quercitrin implant surfaces were biocompatible and decreased osteoclastogenesis in vitro and in vivo. This could be used to improve the performance of dental implants.

• Dahl, Bjørn Einar; Dahl, Jon Einar & Rønold, Hans Jacob (2018). Digital evaluation of marginal and internal fit of single-crown fixed dental prostheses. European Journal of Oral Sciences. ISSN 0909-8836. p. 1–6. doi: 10.1111/eos.12576. Full text in Research Archive Show summary

  The present study used a new, digitized version of the impression replica technique, namely the dual‐scan technique, to evaluate the adaptation of single‐crown fixed dental prostheses (FDPs). Scans of the bare master model and of the master model with a silicone layer representing the cement layer were superimposed and analyzed using designated software. Single crowns produced using the lost‐wax metal casting technique were included. The cement space of the band width, 0.5–1.0 mm from the preparation margin (marginal fit), was smallest for crowns made from laser‐sintered cobalt‐chromium. The internal fit in both mesial‐distal and buccal‐palatal directions was statistically significantly better for crowns made using the conventional lost‐wax metal casting technique than for crowns produced using computer‐aided design/computer‐aided manufacturing (CAD/CAM). Fixed dental prostheses produced by milled cobalt‐chromium had the loosest internal fit. The results agree with those of our previous study of the same test specimens, in which the triple‐scan method was used, and imply that the dual‐scan method is well suited for adaptation studies.

• 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.

• Satué, María; Monjo, Marta; Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Ramis, Joana M. (2017). Titanium implants coated with UV-irradiated vitamin D precursor and vitamin E: in vivo performance and coating stability. Clinical Oral Implants Research. ISSN 0905-7161. 28(4), p. 424–431. doi: 10.1111/clr.12815. Full text in Research Archive
• Dahl, Bjørn Einar; Rønold, Hans Jacob & Dahl, Jon Einar (2017). Internal fit of single crowns produced by CAD/CAM and lost-wax metal casting technique assessed by the triple-scan protocol. The Journal of prosthetic dentistry (Print). ISSN 0022-3913. 117(3), p. 400–404. doi: 10.1016/j.prosdent.2016.06.017. Full text in Research Archive Show summary

  Objectives: To digitally study the internal fit of single crown fixed dental prostheses produced by CAD/CAM and by lost-wax and metal casting techniques. Methods: On an upper jaw simulator with KaVo typodont teeth, the left insisor was prepared for single crown. Impression and scans were taken and three copings were manufactured from each group: milled pre-sintered zirconia, milled hot isostatic pressed zirconia, milled lithium disilicate, milled cobalt-chromium, and laser-sintered cobalt- chromium using CAD/CAM technique and cobalt-chromium by the conventional lost-wax and metal casting technique. The internal fit of crowns produced by CAD/CAM technique was compared to crowns produced by metal casting technique. The internal fit was evaluated in buccal-palatinal and in mesio-distal directions using the triple-scan protocol and GOM Inspect software. Results: The internal gaps in mesio-distal and buccal-palatinal directions were statistically smaller for crowns made by conventional lost-wax and metal casting technique compared to crowns produced by CAD/CAM technique (Table 1). Conclusions: The triple-scan method revealed that single crowns made by lost-wax and metal casting technique had better internal fit than crowns produced by CAD/CAM technique.

• 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
• Tamim, Hazem; Skjerven, Finn Henrik; Ekfeldt, Anders & Rønold, Hans Jacob (2014). Clinical evaluation of CAD/CAM metal-ceramic posterior crowns fabricated from intraoral digital impressions. International Journal of Prosthodontics. ISSN 0893-2174. 27(4), p. 331–337. doi: 10.11607/ijp.3607. Full text in Research Archive
• Walter, Martin Sebastian; Frank, Matthias Johannes; Satué, María; Cabrer, Marta Monjo; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter [Show all 7 contributors for this article] (2014). Bioactive Implant Surface with Electrochemically Bound Doxycycline Promotes Bone Formation Markers In Vitro and In Vivo. Dental Materials. ISSN 0109-5641. 30(2), p. 200–214. doi: 10.1016/j.dental.2013.11.006. Full text in Research Archive Show summary

  Objectives: The objective of this study was to demonstrate a successful binding of Doxy hyclate onto a titanium zirconium alloy surface. Method: The coating was done on titanium zirconium coins in a cathodic polarization setup. The surface binding was analysed by SEM, SIMS, UV-Vis, FTIR and XPS. The in vitro biological response was tested with MC3T3-E1 murine pre-osteoblast cells after 14 days of cultivation and analysed in RT-PCR. A rabbit tibial model was also used to confirm its bioactivity in vivo after 4 and 8 weeks healing by means of microCT. Results: A mean of 141 µg/cm² of Doxy was found firmly attached and undamaged on the surface. Inclusion of Doxy was documented up to a depth of approximately 0.44 µm by tracing the 12C carbon isotope. The bioactivity of the coating was documented by an in vitro study with murine osteoblasts, which showed significantly increased alkaline phosphatase and osteocalcin gene expression levels after 14 days of cell culture along with low cytotoxicity. Doxy coated surfaces showed increased bone formation markers at 8 weeks of healing in a rabbit tibial model. Significance: The present work demonstrates a method of binding the broad spectrum antibiotic doxycycline (Doxy) to an implant surface to improve bone formation and reduce the risk of infection around the implant. We have demonstrated that TiZr implants with electrochemically bound Doxy promote bone formation markers in vitro and in vivo.

• 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
• Dahl, Bjørn Einar & Rønold, Hans Jacob (2014). Digitale avtrykk. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 124(2), p. 108–114. Full text in Research Archive
• Cabrer, Marta Monjo; Ramis, Joana M.; Rønold, Hans Jacob; Taxt-Lamolle, Sebastien Francis Michel; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2013). Correlation between molecular signals and bone bonding to titanium implants. Clinical Oral Implants Research. ISSN 0905-7161. 24(9), p. 1035–1043. doi: 10.1111/j.1600-0501.2012.02496.x. Full text in Research Archive
• 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. --------------------------------------------------------------------------------

• 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
• 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
• Ellingsen, Jan Eirik; Ekstrand, Karl; Saxegaard, Erik; Ekfeldt, Anders & Rønold, Hans Jacob (2010). Forskning kan hjälpa vid val av implantatförankrad protetik. Tandläkartidningen. ISSN 0039-6982. 102(1), p. 84–89. Full text in Research Archive
• Schade, R; Sikiric, MD; Lamolle, Sebastien Francis; Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Liefeith, K [Show all 8 contributors for this article] (2010). Biomimetic organic-inorganic nanocomposite coatings for titanium implants. In vitro and in vivo biological testing. Journal of Biomedical Materials Research. Part A. ISSN 1549-3296. 95A(3), p. 691–700. doi: 10.1002/jbm.a.32888. Full text in Research Archive
• Ellingsen, Jan Eirik; Ekfeldt, Anders; Ekstrand, Karl; Saxegaard, Erik & Rønold, Hans Jacob (2010). Suksess og overlevelse av implantatforankret protetikk. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 120(2), p. 88–93. Full text in Research Archive
• Lundvall, Per Kristian; Ruyter, Eystein; Rønold, Hans Jacob & Ekstrand, Karl (2009). Comparison of Different Etching Agents and Repair Materials Used on Feldspathic Porcelain. Journal of Adhesion Science and Technology. ISSN 0169-4243. 23(7-8), p. 1177–1186. doi: 10.1163/156856109X452684. Full text in Research Archive Show summary

  Abstract: When fractures of fixed partial dentures occur, they cause an aesthetic and functional dilemma both for the patient and the dentist. Re-make of the entire restoration is an option, but not always desirable. Previous studies have provided several options for ceramic reparation, but there is limited consensus about this issue. The aim of this study was to test the shear bond strength due to four different etching agents for ceramic repair. The goal was to find a substitute for hydrofluoric acid as etching agent with less toxicity. Ideally, the repair of ceramics must meet both functional and aesthetic requirements. A total of 70 square shaped feldspathic porcelain disks of dimensions 10 mm × 10 mm × 3 mm were produced and embedded in cylindrical polyethylene walled poly(methyl methacrylate) (PMMA) blocks (16 mm diameter and 12 mm thick). All specimens were wet-ground with silicon carbide papers down to P4000. For one of the groups ten cylindrical ceramic specimens (diameter 5 mm and 2.5 mm high) were made and wet-ground to P4000. The blocks were divided into 7 groups with 10 specimens for each group. In six of the groups composite cylinders were bonded to the porcelain with different pretreatments of the porcelain. As etching agents 9% hydrofluoric acid (HF), 35% phosphoric acid (PO), 15% hydrochloric acid (HCl) and 15% potassium fluoride/hydrogen fluoride (KF·HF) were tested. This study compared a one-part (activated) silane and a new two-part silane. In one group two porcelain specimens were bonded with composite veneer cement. All the specimens were thermocycled for 5000 cycles from 5°C to 55°C before shear bond test. The best overall result was obtained in group 6 (two porcelain specimens bonded with veneer cement), and the mean shear bond strength was 24.5 MPa. The lowest values were obtained in group 4 with 35% phosphoric acid, and group 5 with 15% hydrochloric acid as the etching agent (6.5 and 0.8 MPa, respectively). Pretreatment with either 9% HF or 15% KF·HF as the etching agent combined with two-part silane gave good adhesion for porcelain reparations.

• Mihailescu, IN; Lamolle, Sebastien Francis; Socol, G; Miroiu, F; Rønold, Hans Jacob & Bigi, A [Show all 9 contributors for this article] (2008). In vivo tensile tests of biomimetic titanium implants pulsed laser coated with nanostructured calcium phosphate thin films. Optoelectronics and Advanced Materials Rapid Communications. ISSN 1842-6573. 2, p. 337–341. Full text in Research Archive
• Monjo, Marta; Lamolle, Sebastien Francis; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob & Ellingsen, Jan Eirik (2008). In vivo expression of osteogenic markers and bone mineral density at the surface of fluoride-modified titanium implants. Biomaterials. ISSN 0142-9612. 29, p. 3771–3780. doi: 10.1016/j.biomaterials.2008.06.001. Full text in Research Archive
• Sikiric, M. Dutour; Elkaim, R.; Lamolle, Sebastien Francis; Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Furedi-Milhofer, H. [Show all 7 contributors for this article] (2006). Biomimetic Organic_Inorganic Nanocomposite Coatings for Titanium Implants.II. Biological "In Vitro" and "In Vivo" Characterization. Key Engineering Materials. ISSN 1013-9826. Full text in Research Archive
• Khadra, Maawan; Rønold, Hans Jacob; Lyngstadaas, Ståle Petter; Ellingsen, Jan Eirik & Haanæs, Hans R (2004). Low-level laser therapy stimulates bone-implant interaction: an experimental study in rabbits. Clinical Oral Implants Research. ISSN 0905-7161. 15, p. 325–332. Full text in Research Archive
• Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2003). Tensile force testing of optimized coin-shaped titanium implant attachment kinetics in the rabbit tibiae. Journal of Materials Science. ISSN 0022-2461. p. 843–849. Full text in Research Archive
• Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Ellingsen, Jan Eirik (2003). Analysing the optimal value for titanium implant roughness in bone attachment using a tensile test. Biomaterials. ISSN 0142-9612. 24, p. 4559–4564. Full text in Research Archive
• Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Ellingsen, Jan Eirik (2003). A study on the effect of dual blasting with TiO2 on titanium implant surface on functional attachment in bone. Journal of Biomedical Materials Research. ISSN 0021-9304. 67A(2), p. 524–530. Full text in Research Archive
• Rønold, Hans Jacob & Ellingsen, Jan Eirik (2002). The use of a coin shaped implant for direct in situ measurement of attachment strength for osseointegrating biomaterial surfaces. Biomaterials. ISSN 0142-9612. 23(10), p. 2201–2209. Full text in Research Archive
• Rønold, Hans Jacob & Ellingsen, Jan Eirik (2002). Effect of micro-roughness produced by TiO2 blasting--tensile testing of bone attachment by using coin-shaped implants. Biomaterials. ISSN 0142-9612. 23, p. 4211–4219. Full text in Research Archive
• Duyck, Jocke; Rønold, Hans Jacob; Oosterwyck, H. Van; Naert, Ignace; Sloten, J. Vander & Ellingsen, Jan Eirik (2001). The influence of static and dynamic loading on marginal bone reactions around osseointegrated implants: an animal experimental study. Clinical Oral Implants Research. ISSN 0905-7161. 12(3), p. 207–218. Full text in Research Archive

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• Schriwer, Christian & Rønold, Hans Jacob (2021). Sementeringsprosedyrer for permanente indirekte restaureringer. Den norske tannlegeforenings Tidende. ISSN 0029-2303. 131(6), p. 586–596. Full text in Research Archive
• Herlofson, Bente Brokstad; Preus, Hans Ragnar; Rønold, Hans Jacob; Ørstavik, Dag & Reppen, Kjetil (2017). Hvorfor gikk det galt? Full text in Research Archive
• Dahl, Bjørn Einar; Rønold, Hans Jacob & Dahl, Jon Einar (2017). Internal Fit of Fixed Dental Prostheses Made From Zirconia. Full text in Research Archive
• Sagen, Mina Aker; Kvam, Ketil; Ruyter, Eystein I.; Dahl, Jon Einar & Rønold, Hans Jacob (2017). Adhesion of Surface Modified Zirconia to Dentin Using Resin Cement. Full text in Research Archive
• Dahl, Jon Einar & Rønold, Hans Jacob (2016). Internal fit of single crowns produced by CAD-CAM and lost-wax metal casting technique assessed by the triple-scan protocol. The Journal of prosthetic dentistry (Print). ISSN 0022-3913. doi: 10.1016/j.prosdent.2016.06.017. Full text in Research Archive
• Preus, Hans Ragnar; Reppen, Kjetil & Rønold, Hans Jacob (2016). Kurs i behandlingsplanlegging. Full text in Research Archive
• Rønold, Hans Jacob; Saxegaard, Erik & Ellingsen, Jan Eirik (2015). Hvordan sikre en god start på en vellykket tannbehandling? Den norske tannlegeforenings Tidende. ISSN 0029-2303. 125(2), p. 162–167. Full text in Research Archive
• Walter, Martin Sebastian; Frank, Matthias Johannes; Satué, María; Monjo, Marta; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter [Show all 7 contributors for this article] (2014). Erratum; Bioactive implant surface with electrochemically bound doxycycline promotes bone formation markers in vitro and in vivo (Dental Materials (2014) 30:2 (200-214)). Dental Materials. ISSN 0109-5641. 30(4), p. 463–463. doi: 10.1016/j.dental.2014.01.015. 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
• 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.

• Ellingsen, Jan Eirik & Rønold, Hans Jacob (2012). Gjenomtenkt behandlingsplan - essensielt for en forutsigbar implantatbasert protetisk behandling. Full text in Research Archive
• Monjo, Marta; Lyngstadaas, Ståle Petter; Rubert, Marina; Taxt-Lamolle, Sebastien Francis Michel; Rønold, Hans Jacob & Ellingsen, Jan Eirik (2011). Increased Fixation of Fluoride-modified Implants in Osteoporotic Rats. 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
• 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; 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
• Monjo, Marta; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob; Lamolle, Sebastien Francis & Ellingsen, Jan Eirik (2006). EFFECT OF FLUORIDE-MODIFIED TITANIUM IMPLANTS ON INFLAMMATION, BONE FORMATION AND RESORPTION MARKERS AT THE BONE-IMPLANT INTERFACE. Full text in Research Archive
• Monjo, Marta; Lyngstadaas, Ståle Petter; Rønold, Hans Jacob; Yousefi, Shahbaz & Ellingsen, Jan Eirik (2006). Fluoride-modified titanium implants enhance osteoblast differentiation both in vitro and in vivo. Full text in Research Archive
• Lamolle, Sebastien Francis; Monjo, Marta; Haugen, Håvard Jostein; Petzold, Christiane; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter [Show all 7 contributors for this article] (2006). Characterization and in vivo function of hydrofluoric acid modified titanium implants. Full text in Research Archive
• Lyngstadaas, Ståle Petter; Monjo, Marta; Lamolle, Sebastien Francis; Rønold, Hans Jacob & Ellingsen, Jan Eirik (2006). Expression of markers during bone healing and their significance in evaluating bone bonding and implant performance. Full text in Research Archive
• Monjo, Marta; Lamolle, Sebastien Francis; Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2005). Osteocalcin mRNA expression positively correlates with bone attachment of titanium implants in the rabbit tibiae. Full text in Research Archive
• Monjo, Marta; Lamolle, Sebastien Francis; Ellingsen, Jan Eirik; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter (2005). Markers for early implant performance correlating with bonding strength between titanium implants and bone. Full text in Research Archive
• Riksen, Elisabeth Aurstad; Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2003). The effect of EMD and rAmelogenin on titanium implant attachment in cortical bone. Full text in Research Archive
• Ellingsen, Jan Eirik; Rønold, Hans Jacob; Boström, Kristina Junemo; Holmén, Anders & Hansson, Stig (2003). Enhanced bone-to-implant attachment of fluoride-modified titanium implants. Full text in Research Archive
• Berntsen, Christian Skoe; Riksen, Elisabeth Aurstad; Ellingsen, Jan Eirik; Slaby, Ivan; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter (2003). Improved Titanium Implant Attachment in Cortical Bone by Application of rAmelin. Full text in Research Archive
• Riksen, Elisabeth Aurstad; Berntsen, Christian Skoe; Ellingsen, Jan Eirik; Deutsch, Dan; Rønold, Hans Jacob & Lyngstadaas, Ståle Petter (2003). The Effects of EMD and rhAmelogenin on Titanium Implant Attachment in Cortical Bone. Full text in Research Archive
• Berntsen, Christian Skoe; Riksen, Elisabeth Aurstad; Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2002). Molecular force probing of amelogenin-titanium interactions. Full text in Research Archive
• Rønold, Hans Jacob (2002). The effect of surface roughness on functional attachment as measured by tensile test method. Full text in Research Archive
• Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Ellingsen, Jan Eirik (2002). The effect of surface roughness on functional attachment measured by tensile testing. Full text in Research Archive
• Riksen, Elisabeth Aurstad; Rønold, Hans Jacob & Ellingsen, Jan Eirik (2002). An in vivo method for measuring bone attachment of bone- anchored implants. Full text in Research Archive
• Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2002). Bone attachment assessed by tensile testing of osseointegrating coin-shaped titanium implants. Full text in Research Archive
• Riksen, Elisabeth Aurstad; Berntsen, Christian Skoe; Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2002). An in vivo method for measuring extracellular matrix guided osseointegration. Full text in Research Archive
• Maawan, Khadra; Rønold, Hans Jacob & Haanæs, Hans R (2002). Low level laser effect on the osseointegration between implants and bone. Full text in Research Archive
• Rønold, Hans Jacob; Lyngstadaas, Ståle Petter & Ellingsen, Jan Eirik (2001). Bone bonding assessed by tensile testing of osseointegrating coin-shaped titanium implants. Transactions of the Society for Biomaterials. ISSN 1527-6317. p. 537–537. Full text in Research Archive
• Ellingsen, Jan Eirik & Rønold, Hans Jacob (2001). Improved bone response to chemically modified titanium implants. Transactions of the Society for Biomaterials. ISSN 1527-6317. p. 261–261. Full text in Research Archive
• Rønold, Hans Jacob & Ellingsen, Jan Eirik (2001). A Study on the Effect of Acid-Etched Surfaces of Titanium Implants on Functional Attachment in Bone. Full text in Research Archive
• Rønold, Hans Jacob & Ellingsen, Jan Eirik (2001). A Study on the Effect of Macro and Micro Roughness of Titanium Implants on Functional Attachment in Bone. Full text in Research Archive
• Duyck, Jocke; Ellingsen, Jan Eirik; Rønold, Hans Jacob; Oosterwyck, H. Van; Sloten, J. Vander & Naert, Ignace (2000). Bone response on static and dynamic loading of implants: a study in rabbits. Full text in Research Archive
• Rønold, Hans Jacob; Ellingsen, Jan Eirik & Lyngstadaas, Ståle Petter (2000). Functional attachment and bone contact in microrough titanium implants. Full text in Research Archive
• Duyck, Jocke; Ellingsen, Jan Eirik; Rønold, Hans Jacob; Oosterwyck, H Van; Sloten, J Van der & Naert, Ignace (2000). Bone responce on static and dynamic loading of implants: a study in rabbits. Journal of Dental Research. ISSN 0022-0345. 79, p. 385–385. Full text in Research Archive
• Rønold, Hans Jacob & Ellingsen, Jan Eirik (2000). AN IN-VIVO METHOD FOR FUNCTIONAL ATTACHMENT MESSUREMENTS IN BONE ANCHORED IMPLANTS. Full text in Research Archive
• Rønold, Hans Jacob & Ellingsen, Jan Eirik (1999). A study on the effect of surface roughness of titanium implants on retention in bone. Full text in Research Archive
• Rønold, Hans Jacob (2003). The effect of surface micro structure on titanium implant attachment to bone. Lobo Media AS. ISSN 9788249701605. Full text in Research Archive

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