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Irena Sailer, Prof Dr med dent, is chair of the Division of Fixed Prosthodontics and Biomaterials at the University of Geneva and adjunct associate professor in the Department of Preventive and Restorative Sciences at the University of Pennsylvania School of Dental Medicine. In 2019, she received an Honorary Skou Professorship of digital dental technologies, fixed and implant prosthodontics, and biomaterials at Aarhus University, Denmark. Dr Sailer is editor-in-chief of The International Journal of Prosthodontics and coauthor of over 150 peer-reviewed publications as well as the books Fixed Restorations: A Clinical Guide to the Selection of Materials and Fabrication Technology (Quintessence, 2021) and Color in Dentistry (2017). She holds several patents on esthetic coatings of dental/medical devices and a digital dental splint.
Bridging the Gap Between Science and Clinical Practice
Issue cycle: bimonthly Language: English Impact factor: 1.681 (2020) Category: Prosthodontics Editor-in-chief: Prof. Dr. med. dent. Irena Sailer QP USA
DON'T PANIC! Complications in dental medicine06.05.2022 — 07.05.2022Palazzo dei Congressi Lugano, Lugano, Switzerland
Speakers: Goran Benic, Eriberto Bressan, Urs Brodbeck, Luca Cordaro, Petra Gierthmühlen, Christoph Hämmerle, Markus B. Hürzeler, Gaetano Paolone, Giulio Rasperini, Fidel Ruggia, Irena Sailer, Giovanni E. Salvi, Matthias Zehnder, Giovanni Zucchelli
Institute for Research and Education in Dental Medicine
Contemporary prosthodontics: Where do we stand, where are we heading?22.01.2022, 9:00 — 17:30 (CET)University of Zurich Irchel Campus, Zürich, Switzerland
Speakers: Thomas Attin, Beatrice Beck Schimmer, Tord Berglundh, Rino Burkhardt, Lyndon F. Cooper, Christer Dahlin, Stefano Gracis, Christoph Hämmerle, Lisa J. A. Heitz-Mayfield, Markus B. Hürzeler, Ronald E. Jung, Nadja Nänni, Mutlu Özcan, Marc Quirynen, Irena Sailer, Christian S. Stohler, Daniel S. Thoma
Implantology: Beyond your expectations12.10.2021 — 14.10.2021online
Speakers: Enrico Agliardi, Alessandro Agnini, Andrea Agnini, Mauricio Araujo, Goran Benic, Juan Blanco Carrión, Daniel Buser, Francesco Cairo, Raffaele Cavalcanti, Tali Chackartchi, Luca Cordaro, Jan Cosyn, Holger Essig, Vincent Fehmer, Stefan Fickl, Alberto Fonzar, Helena Francisco, German O. Gallucci, Ramin Gomez-Meda, Óscar Gonzáles, Robert Haas, Arndt Happe, Alexis Ioannidis, Ronald E. Jung, Niklaus P. Lang, Tomas Linkevičius, Iva Milinkovic, Sven Mühlemann, Katja Nelson, Sergio Piano, Michael A. Pikos, Bjarni E. Pjetursson, Marc Quirynen, Franck Renouard, Isabella Rocchietta, Dennis Rohner, Irena Sailer, Henning Schliephake, Shakeel Shahdad, Massimo Simion, Ali Tahmaseb, Hendrik Terheyden, Jochen Tunkel, Stefan Vandeweghe, Piero Venezia, Stijn Vervaeke, Martin Wanendeya, Georg Watzek, Giovanni Zucchelli
Purpose: To evaluate the survival rates and technical outcomes of minimally invasive full-mouth rehabilitations in patients affected by dental erosion and attrition.
Materials and methods: For this retrospective study, 28 subjects (8 women, 20 men; mean age: 45.6 years) who suffered from generalized erosions and attrition and who were treated according to the 3-step technique were invited to participate. The patient records were reviewed, and the restorations were clinically and radiographically examined. This part of the study (part 1) evaluated restoration survival and technical outcomes using the modified United States Public Health Service criteria (mUSPHS). Survival analysis was performed using Kaplan-Meier survival statistics, and comparison between subgroups was made using log-rank test. For all other comparisons, cross-tabulations of occurrence were performed, and significance was tested using Pearson chi-square test. The level of statistical significance was set at P < .05.
Results: A total of 19 patients (3 women, 16 men; mean age: 45.6 years) agreed to participate. In these patients, 406 restorations (149 direct composites, 110 onlays, 147 veneers) supported by 365 teeth were examined. The mean time in service was 71.8 ± 28.6 months. Six failed restorations were identified; all were direct composites. The 6-year survival rates were 97.3% for direct composites, 98.2% for onlays, and 100% for veneers (P > .05). No differences were found among materials and locations of the restorations. Nineteen technical complications included 14 partial fractures, 3 fissures, 1 wear, and 1 decementation. The mUSPHS evaluation showed good technical outcomes. Presence or absence of a nightguard influenced restoration survival (P = .003).
Conclusion: Minimally invasive rehabilitations of patients with erosions/attrition with the 3-step technique are a reliable treatment option in the medium term. Protective nightguards are recommended.
Purpose: To digitally evaluate the volumetric wear of four different implant-crown materials and their antagonists after artificial aging using an intraoral scanner (IOS) device and a laboratory desktop scanner.
Materials and methods: A total of 48 implants were restored with monolithic crowns divided according to restorative material: lithium disilicate (LDS), zirconia (ZR), polymerinfiltrated ceramic network (PICN), and porcelain fused to metal (PFM). Each specimen was scanned using a desktop scanner (LAB; iScan D104, IMETRIC 3D) and an IOS (TRIOS 3, 3Shape) before and after chewing simulation (1,200,000 cycles, 49 N, steatite antagonist, 5°C to 50°C). The obtained STL files were superimposed, and the volumetric loss of substance of the crowns and their antagonists was quantified (Materialise 3-matic). Kruskal-Wallis, Spearman rho, and paired t tests were used to analyze the data (α = .05).
Results: The means of volume loss for each restorative material varied between 0.05 ± 0.06 mm3 (ZR with IOS) and 3.42 ± 1.65 mm3 (LDS with LAB). The wear of the antagonists was significantly lower (P < .05) for ZR than the other groups. Increased wear of the crowns was highly correlated with increased wear of their antagonists (rs = 0.859). When comparing the wear measurement using the two scanning devices, no difference in mean volume loss was found (IOS: 1.81 ± 1.81 mm3; LAB: 1.82 ± 1.78 mm3) (P = .596).
Conclusion: Polished ZR was the most wear-resistant material and the least abrasive to the respective antagonist among the tested ceramics. For the quantification of wear, this IOS device can be used as an alternative to desktop scanners.
In recent years, numerous new dental materials have been introduced as alternatives to metal-ceramics for restorations on teeth and implants. This position paper presents the current evidence and respective clinical recommendations of the European Association for Osseointegration (EAO), one of the scientific partners of the International Journal of Prosthodontics, on material selection for single crowns (SCs) and multiple-unit implant-supported fixed dental prostheses (FDPs). Metal-ceramic restorations can be utilized in most clinical indications and are preferred to ceramic restorations in incidences such as long clinical implant crowns; cantilever implant restorations where one implant is supporting two crowns; implant-supported FDPs with extension units extending more than 7 to 8 mm (premolar size); implant-supported FDPs with more than two pontics; and implant-supported FDPs with small connector diameters due to limited intraocclusal space. Veneered or monolithic zirconia-ceramic and veneered or monolithic reinforced glass-ceramic implant-supported SCs are indicated for most SC cases in both the anterior and posterior areas. Today, implant-supported zirconia-ceramic FDPs that are conventionally veneered cannot be considered the material of first priority due to the pronounced risk for fracture of the framework and catastrophic fracture of the veneering material. Monolithic zirconia FDPs are a promising alternative to veneered implant-supported zirconia-ceramic FDPs. The mechanical stability of the translucent and shaded zirconia differs significantly between the grades of translucency. This must always be considered when clinical indications are recommended. As this specific area of prosthodontics is evolving fast, numerous studies evaluating different material options in implant prosthodontics are currently performed worldwide, and future consensus meetings will refine the present recommendations. The EAO will therefore regularly publish updated position papers on relevant topics.
The International Journal of Oral & Maxillofacial Implants, 1/2022
DOI: 10.11607/jomi.8923Pages 19-29, Language: EnglishCalderon, Ulises / Hicklin, Stefan Paul / Mojon, Philippe / Fehmer, Vincent / Nesic, Dobrila / Mekki, Mustapha / Sailer, Irena
Purpose: This in vitro study evaluated technical outcomes of monolithic zirconia implant-supported fixed dental prostheses (iFDPs) supported by different designs of titanium base abutments after aging and static load testing.
Materials and methods: Sixty three-unit monolithic zirconia (yttrium oxide partially stabilized tetragonal zirconia polycrystals; Y-TZP)iFDPs were produced and divided into four groups: group A-conical titanium base abutments for the prosthesis; group B-cylindrical titanium base abutments for the crown; group C-conical titanium base abutment for the prosthesis and cylindrical titanium base abutment for the crown; group D-cylindrical titanium base abutments for the prosthesis. The samples were subjected to an aging protocol and to continuous static loading until failure and analyzed visually and with specific software. The technical outcomes comprised the occurrence of debonding, screw loosening, deformation and fracture, abutment deformation and fracture, implant deformation and fracture, zirconia chipping and fracture, and bending moments. The Pearson chi-squared test (χ2) and Fischer exact test were used to compare the outcomes. The Kolmogorov-Smirnov test was used to evaluate data distribution of the bending moments. Analysis of variance (ANOVA) was used for the analysis of parametric data distribution, and the Kruskal-Wallis test was used for nonparametric data distribution.
Results: After aging, a higher percentage of debonding (P = .042) and micromovement (P = .034) was recorded in group C (P = .042). The conical titanium base abutments had a higher debonding (P = .049) and a higher macromovement rate (P = .05). The static load test showed higher bending moments in group D (P = .001) and lower bending moments in group A (P = .001). Debonding was highest in group C (P = .001) and lowest in group A (P = .002). Complete loss of retention rate was highest in group C (P = .001). The conical titanium base abutment had the highest debonding rate (P = .001) and complete loss of retention (P = .001). The micromovement rate was the highest for cylindrical titanium base abutments for the crown (P = .001). The lowest screw loosening, zirconia chipping, and fracture rate (P = .001) and the highest screw deformation (P = .004) were recorded in group A. The screw deformation rate was lowest in the cylindrical titanium base abutments for the crown (P = .008).
Conclusion: The mixed titanium base abutment design comprising one conical and one cylindrical abutment in Y-TZP iFDPs led to the highest debonding rate. The cylindrical titanium base abutment for the prosthesis provided a lower percentage of debonding and the highest load resistance.
Keywords: bending moments, debonding, implant-supported fixed dental prostheses, monolithic zirconia, technical complications, titanium base abutment
Purpose: To evaluate the mechanical stability and complication rates of titanium (Ti) and zirconia (Zr) abutments restored with cantilevered fixed dental prostheses (cFDPs) when supported by one or two implants.
Materials and Methods: A total of 32 specimens were fabricated. Half of the specimens received one implant, and the other half received two implants to simulate the clinical situation of two or three missing maxillary incisors, respectively. Each group was divided into two subgroups (n = 8). The Ti-1 and Ti-2 groups received Ti abutments (Anatomic Abutment, Straumann) supporting two- or three-unit metal cFDPs, respectively, while Zr-1 and Zr-2 groups received Zr abutments (IPS e.max Anatomic Abutment, Straumann). Following the cementation of cFDPs using resin cement (Multilink Automix, Ivoclar Vivadent), the specimens were subjected to thermomechanical fatigue load and then subsequently loaded until fracture in a universal testing machine. Following the static loading test, stereomicroscopic analyses (Carl Zeiss) were done to identify the weakest component of the cFDP, abutment, and implant assembly. Mann-Whitney U test was used to evaluate the effect of the number of supporting implants and abutment material on fracture strength values, and the level of statistical significance was set at 5% (α = .05).
Results: All specimens survived aging, and no screw loosening or fracture was recorded. The mean fracture strength values were 226 N (± 26.45), 551.12 N (± 82.19), 601 N (± 41.51), and 664.5 N (± 37.59) for Zr-1, Zr-2, Ti-1, and Ti-2, respectively. The difference between fracture strength values of the Ti and Zr groups was significant in favor of Ti abutments (P < .001). The number of supporting implants showed a significantly positive effect on the fracture strength of Zr abutments.
Conclusion: Zr abutments demonstrated lower fracture strength values than Ti abutments independent from the number of supporting implants when used under cFDPs. Two implant–supported cFDPs with zirconia abutments have the potential to withstand physiologic forces applied in the anterior region.
The International Journal of Prosthodontics, 5/2021
DOI: 10.11607/ijp.6999Pages 560-566d, Language: EnglishStucki, Lukas / Asgeirsson, Asgeir G / Jung, Ronald E / Sailer, Irena / Hämmerle, Christoph Hf / Thoma, Daniel S
Purpose: To assess the clinical, technical, and esthetic outcomes of directly veneered zirconia abutments cemented onto nonoriginal titanium bases over a 3-year follow-up.
Materials and Methods: A total of 24 healthy patients with a single missing tooth in the maxilla or mandible (incisors, canines, or premolars) received a two-piece implant with a screw-retained veneered zirconia restoration extraorally cemented onto a titanium base abutment. Baseline measurements and follow-up examinations were performed at 6 months, 1 year, and 3 years following loading. Radiographic, clinical, technical, and esthetic parameters were assessed. Wilcoxon signed rank test was used to analyze the data.
Results: Mean marginal bone levels measured 0.54 ± 0.39 mm (median: 0.47 mm, range: 0.07 to 1.75 mm) at baseline and 0.52 ± 0.39 mm (median: 0.39 mm, range: 0.06 to 1.33 mm) at 3 years. Mean probing depth around the implants increased from 3.0 ± 0.6 mm at baseline to 3.8 ± 0.8 mm at 3 years (P = .001). Bleeding on probing changed from 27.1% ± 20.7% at baseline to 51.5% ± 26.1% at 3 years (P = .001). The mean plaque control record amounted to 11.1% ± 21.2% at baseline and 14.4% ± 13.89% at 3 years (P = .261). Two implants were lost at 3.5 and 30 months postloading due to periimplantitis, resulting in a 91.7% implant survival rate. Patient satisfaction was high at 3 years.
Conclusion: Zirconia restorations cemented onto the tested nonoriginal titanium bases should not be recommended for daily clinical use, as they were associated with significant increases in BOP and PD values and varying marginal bone levels 3 years after placement.
Purpose: To investigate the differences in accuracy (trueness and precision) of five different optical impression systems.
Materials and methods: The accuracy of the following optical impression systems was tested: (1) CEREC Bluecam (BL; Dentsply Sirona), (2) CEREC Omnicam (OM, Dentsply Sirona); (3) PlanScan (PL; Planmeca); (4) True Definition Scanner (TD; 3M ESPE); and (5) Trios 3 (TR; 3Shape). A standard plastic study model represented a patient with a fully dentate maxilla (ANA-4 V CER, frasaco). Three clinical situations were simulated: Patient 1 (P1): fully dentate; Patient 2 (P2): anterior partial edentulism (two missing incisors); and Patient 3 (P3): posterior partial edentulism (P3) (missing premolar and molar). The models were scanned with a reference scanner (IScan D104i, Imetric), and the digitalized models were used as reference for all comparisons. Then, optical impressions were made for the three clinical scenarios (n = 10 per group).
Results: In situation P1, the TD group provided the highest trueness (180.2 ± 46.3μm). In situation P2, the highest trueness was found in the TD (97.9 ± 27.6 μm) and TR (105 ± 9.5μm) groups, and in situation P3, TR had the highest trueness (P < .05) with a median RMS value of 76.2 ± 5.6 μm. In terms of precision, TR provided the highest precision (P < .05) in all three clinical situations, with RMS values 76.7 ± 26 μm for P1, 46.8 ± 14.1 μm for P2, and 39.7 ± 9.1 μm for P3.
Conclusion: Two optical impression systems (TR and TD) were superior to the other tested systems in most of the measurements. However, none of the tested systems was clearly superior with respect to both trueness and precision.