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To investigate survival rates, technical and biologic outcomes of buccally micro-veneered all-ceramic single implant crowns.Sixty subjects randomly received immediately or early placed implants. Crowns out of lithium-disilicate (n = 30) and zirconia-ceramic (n = 30) were bonded to titanium-base-abutments. Restorations were inspected at baseline (BL) and during follow-up visits (6, 12 months). Technical and biologic parameters were recorded. Data were analysed descriptively. Differences between groups were tested with Student's t-test. Paired T-test was used when comparing data from the same implant or tooth over time. Linear model repeated measures were used to test differences between materials over time. Differences in counts were evaluated using Pearson Chi-square test. The level of significance was at p .05.After a mean observation time of 13.2 ± 2.4 months, 54 restorations were re-examined. The implant survival rate was 98.3%, and the restoration survival rate was 100%. One early implant failure occurred. Two minor chippings occurred in lithium-disilicate restorations. No chippings or fractures occurred in any zirconia restorations at 1 year (0%). The technical complication rate was 3.7%, with 7.7% complications among the lithium-disilicate restorations and no differences between the two materials (p = .558). At 1-year follow-up, mean Bleeding on Probing (BOP) was higher at implants (0.27 ± 0.3) than adjacent teeth (0.17 ± 0.18) (p = .046) with no differences between materials (p = .36). Differences in pocket probing depth (PPD) between implants and adjacent teeth were significant (p .01). Jemt Index improved significantly from BL to 1-y-follow-up (p .001).Preliminary results were good, suggesting that the ceramic type does not impact technical and biologic parameters.

The aim of the study was to identify and report outcome measures and methods of assessment on soft-tissue augmentation interventions in the context of dental implant therapy reported in clinical studies published in the last 10 years.The protocol of this PRISMA 2020-compliant systematic review was registered in PROSPERO (CRD42021252214). A literature search was conducted to identify articles that met the pre-established eligibility criteria. Data of interest, with an emphasis on outcome measures, were extracted. For each outcome, specific methods and timing of assessment were described in detail. Following a critical qualitative analysis of the data, outcome measures were categorized. Primary outcomes were identified and the frequency of reporting in the selected articles was calculated. Additionally, risk of bias assessments were performed for individual articles and primary outcomes.Ninety-two articles, of which 39 reported randomized controlled trials (RCTs), 20 reported non-RCTs, and 33 reported case series studies, were selected. Outcome measures were categorized into either investigator-evaluated outcome measures (i.e., clinical, digital imaging, esthetic, histologic, biomarker, and safety) or patient-reported outcome measures (PROMs). Clinical outcomes were the most frequently reported type of outcome. Considering all categories, the most frequently reported primary outcomes were facial mucosa thickness assessed with clinical methods (22.83%), facial keratinized mucosa width assessed with clinical methods (19.57%), facial mucosal margin position/recession assessed with clinical methods (18.48%), facial mucosa thickness assessed with digital imaging methods (11.96%), facial soft-tissue volume assessed with digital imaging methods (9.78%), and supracrestal tissue height assessed with clinical methods (9.78%). No distinguishable patterns of association between specific types or quality (level of bias) of clinical studies and the choice of primary outcomes were observed.Clinical research on peri-implant soft-tissue augmentation has progressively increased in the last 10 years. Although clinical outcome measures were the most frequently reported outcomes in the selected literature, trends in the field are indicative of a shift from traditional clinical assessment methods to the use of digital technologies. PROMs were generally underreported but should be considered an integral methodological component in future clinical studies.

6. EAO Consensus Conference 2021, online, 11 Feb 2021 - 12 Feb 2021; Clinical oral implants research 32(S21), 336-341 (2021). doi:10.1111/clr.13797 special issue: "Special Issue: The 6th EAO Consensus Conference 2021 / edited by: Irena Sailer, Björn Klinge, Henning Schliephake", Published by Wiley-Blackwell, Oxford

Objectives: To test whether early implant placement with alveolar ridge preservation (ARP) results in different esthetic, clinical and patient-reported outcome measures (PROMs) compared with early implant placement without ARP. Material and methods: Seventy-five patients requiring single tooth extraction in the anterior maxilla were recruited. Following tooth extraction, the patients were randomly allocated to three groups: (a) ARP using demineralized bovine bone mineral containing 10% collagen (DBBM-C) covered by a collagen matrix (CM) (n = 25), (b) ARP using DBBM-C covered with a palatal graft (PG) (n = 25) and (c) spontaneous healing (control) (n = 25). Eight weeks after tooth extraction, a CBCT was taken and early implant placement was performed in all patients. Esthetic, clinical and PROMs were evaluated one year post-loading. Results: A total of 70 patients were available for re-examination at one year post-loading. The median mid-facial mucosal margin change amounted to −0.02 mm (IQR −0.27–0.46) in the CM group, −0.13 mm (IQR −0.44–0.25) in the PG group and −0.14 mm (IQR −0.29–0.07) in the control group, with no significant differences between the groups. Mean PES scores amounted to 7.0 ± 1.4 in the CM group, 7.1 ± 1.5 in the PG group and 7.3 ± 1.7 in the control group without significant differences between the groups. Plaque, bleeding on probing and probing depth did not differ between treatment groups. PROMs in general revealed no significant differences between the groups. Conclusion: Early implant placement with ARP using either a collagen matrix or a palatal graft rendered similar esthetic, clinical and PROMs to early implant placement without ARP. When a failing tooth can be replaced with an implant within 2 months after tooth extraction, the added value of ARP might be clinically negligible.

STATEMENT OF PROBLEM Whether additively produced zirconia could overcome problems with conventional computer-aided design and computer-aided manufacture (CAD-CAM) such as milling inaccuracies and provide accurate occlusal veneers is unclear. PURPOSE The purpose of this in vitro study was to compare the marginal and internal fit of 3D-printed zirconia occlusal veneers with CAD-CAM-fabricated zirconia or heat-pressed lithium disilicate ceramic (LS2) restorations on molars. MATERIAL AND METHODS The occlusal enamel in 60 extracted human molars was removed, with the preparation extending into dentin. Occlusal veneers at a thickness of 0.5 mm were designed and manufactured according to their group allocation: 3DP, 3D-printed zirconia; CAM, milled zirconia; and HPR, heat-pressed LS2. The prepared teeth and restorations were scanned and superimposed, and the marginal and internal adaptation were measured 2- and 3-dimensionally; the production accuracy (trueness) was also measured. The comparisons of the group medians were performed with nonparametric methods and a pairwise group comparison (α=.05). RESULTS Three-dimensionally printed zirconia revealed median outcomes of 95 μm (margin), 252 μm (cusp), 305 μm (fossa), and 184 μm (3D internal adaptation). CAM showed median values of 65 μm (margin), 128 μm (cusp), 203 μm (fossa), and 120 μm (3D internal adaptation). The respective values for the group HPR were 118 μm (margin), 251 μm (cusp), 409 μm (fossa), and 180 μm (3D internal adaptation). Significant differences (P

To analyze changes in radiographic bone density around short implants with and without cantilevers at 5 years post-loading.Thirty-six patients with two adjacent posterior missing teeth participated in this randomized controlled clinical trial. All patients were randomly allocated to receive either two short implants (6 mm) with single-unit restorations (group TWO) or one single short implant (6 mm) with a cantilever restoration (group ONE-C). Patients were followed up at 6 months, 1, 3, and 5 years. Radiographic analysis was performed, through an arbitrary gray scale value (GSV) of the peri-implant bone, assessing the changes in radiographic density between groups and between time points. Differences in GSV between groups and over time were calculated using a generalized estimating equation to allow for adjustments for the correlation within individuals and between time points.At 5 years, 26 patients remained in the study (15 in group ONE-C; 11 in group TWO). Implant survival rates were 80.4% in group TWO and 84.2% in group ONE-C (p = 0.894). The radiographic analysis revealed that GSVs increased in both groups over time (p 0.001). The overall radiographic density was higher in group ONE-C than in group TWO in the maxilla (p = 0.030). Conversely, in the mandible, these significant differences between the groups were not found (p 0.05). Compared to the implants that survived, the implants that failed demonstrated a distinct radiographic density pattern (p 0.05).Within the limitations of the present study, the radiographic bone density in the maxilla appears to increase distinctly around short implants when cantilevers are used. In contrast, the radiographic density in the mandible appears to be unaffected by the use of a cantilever, suggesting a lower threshold of adaptation to occlusal forces and thus a higher susceptibility to overload and implant loss at earlier time points.

Clinical evidence is sparse on whether dentures fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) methods afford superior fit and retention when compared with those fabricated conventionally.The purpose of this clinical controlled crossover study was to evaluate the peak retention force and fit of CAD-CAM manufactured (3D-printed and milled) maxillary complete denture bases and conventional heat-polymerized bases (control).Twenty participants with edentulous maxillary arches were recruited. Impressions were made with a border-molded custom tray, and the resulting definitive cast was scanned. The conventional base was manufactured on the definitive cast with a hook and a 45-degree platform with a central notch and 2 lateral notches. The scan of the definitive cast was used for the fabrication of a milled and a printed base. The platform and hook position on the conventional base were transferred digitally to the milled and printed bases. All bases were scanned. A traction dynamometer was orientated into the notches, and retention was evaluated in the post dam and tuberosity areas. Scans were imported into a comparison software program which matched scans to their corresponding reference and performed a 3-dimensional comparison. The Friedman and Wilcoxon tests were used to compare between groups (confidence interval: 95%, α=.05).Nineteen participants with a mean ±standard deviation age of 64.1 ±14.7 years completed all clinical sessions. No significant difference in peak retention was measured between milled (MB1), printed (PB1), and conventional (CB) bases in the post dam (CB: 12.44 ±9.62 N, PB1: 16.08 ±15.28 N, MB1: 14.52 ±17.07 N) and right tuberosity area (CB: 8.99 ±7.82 N, PB1: 11.28 ±9.57 N, MB1: 11.99 ±12.10 N). In the left tuberosity area, peak retention was lower for CB (10.03 ±8.39 N) than PB1 (14.98 ±14.72 N) and MB1 (13.55 ±15.53 N; P=.05). Compared with the definitive cast, the fit of the conventional base (0.18 ±0.01 mm) was closer than the printed (0.21 ±0.03 mm) and milled bases (0.21 ±0.02 mm) (P.001).The CD bases manufactured by CAD-CAM techniques provided retention and fit similar to that of conventionally manufactured bases and can therefore be considered suitable techniques.

Statement of problem The use of computer-aided design and computer-aided manufacturing (CAD-CAM) technologies is widely established, with single restorations or short fixed partial dentures having similar accuracy when generated from digital scans or conventional impressions. However, research on complete-arch scanning of edentulous jaws is sparse. Purpose The purpose of this pilot in vitro study was to compare the accuracy of a digital scan with the conventional method in a workflow generating implant-supported complete-arch prostheses and to establish whether interference from flexible soft tissue segments affects accuracy. Material and methods An edentulous maxillary master cast containing 6 angled implant analogs was used and digitized with mounted scan bodies by using a high-precision laboratory scanner. The master cast was then scanned 10 times with 4 different intraoral scanners: TRIOS 3 with a complete-arch scanning strategy (TRI1) or implant-scanning strategy (TRI2), TRIOS Color (TRC), CEREC Omnicam (CER), and CEREC Primescan (PS). The same procedure was repeated with 4 different levels of free gingiva (G0–G3). Ten conventional impressions were obtained. Differences in implant position and direction were evaluated at the implant shoulder as mean values for trueness and interquartile range (IQR) for precision. Statistical analysis was performed by using the Kruskal–Wallis and post hoc Conover tests (α=.05). Results At G0, position deviations ranged from 34.8 μm (IQR 23.0 μm) (TRC) to 68.3 μm (12.2 μm) (CER). Direction deviations ranged from 0.34 degrees (IQR 0.18 degrees) (conventional) to 0.57 degrees (IQR 0.37 degrees) (TRI2). For digital systems, the position deviation ranged from 48.4 μm (IQR 5.9 μm) (PS) to 76.6 μm (IQR 8.1 μm) (TRC) at G1, from 36.3 μm (IQR 9.3 μm) (PS) to 79.9 μm (IQR 36.1 μm) (TRI1) at G2, and from 51.8 μm (IQR 14.3 μm) (PS) to 257.5 μm (IQR 106.3 μm) (TRC) at G3. The direction deviation ranged from 0.45 degrees (IQR 0.15 degrees) (CER) to 0.64 degrees (IQR 0.20 degrees) (TRC) at G1, from 0.38 degrees (IQR 0.05 degrees) (PS) to 0.925 degrees (IQR 0.09 degrees) (TRI) at G2, and from 0.44 degrees (IQR 0.07 degrees) (PS) to 1.634 degrees (IQR 1.08 degrees) (TRI) at G3. Statistical analysis revealed significant differences among the test groups for position (G0: P Conclusions Without soft tissue interference, the accuracy of certain digital scanning systems was comparable with that of the conventional impression technique. The amount of flexible soft tissue interference affected the accuracy of the digital scans.

Adequate control of the vertical dimension is of great importance in orthodontic treatment. Although existing evidence is very limited, extraction of four premolars is thought to contribute towards improved control of anterior facial height compared with non-extraction treatment protocols. Thus, the aim of this retrospective cohort study was to compare the effect of fixed-appliance treatment with extraction of four premolars to non-extraction treatment on the skeletal vertical dimension.A consecutive sample of 76 children with skeletal hyperdivergence (49% male; mean age 11.9 years) was divided into two groups for treatment with either non-extraction (n = 31) or extraction of four premolars (n = 45). Baseline characteristics were comparable: overjet 5.1 ± 2.5 mm, overbite 2.4 ± 1.9 mm, ANB angle 4.6 ± 2.3°, and SN-ML angle 40.2 ± 3.5°. Patients were treated with standard edgewise fixed appliances with closing loops/sliding mechanics. Vertical skeletal and dental outcomes were measured on lateral cephalograms before and after treatment. Data were analyzed with linear regression at 5%.Compared to non-extraction treatment, treatment with premolar extractions had no significant effect on the SN-ML angle (difference (Δ) = 0.07°; 95% confidence interval -0.90 to 1.01°; P = 0.88). Statistically significant changes between the extraction and non-extraction groups were only found for the parameters SNA (Δ -1.47°; P = 0.003), ANB (Δ -1.17°; P = 0.004), SN-OP (Δ -1.48°; P = 0.04), and L1-ML (Δ -6.39°; P 0.001).Orthodontic treatment of children with skeletal hyperdivergence using systematic extraction of four premolars had minimal effects on the vertical facial dimension compared to non-extraction treatment.ZIELSETZUNG: Eine adäquate Kontrolle der vertikalen Dimension ist in der kieferorthopädischen Behandlung von großer Bedeutung. Auch wenn die Evidenzlage sehr begrenzt ist, geht man davon aus, dass die Extraktion von 4 Prämolaren im Vergleich zu nichtextraktiven Behandlungsprotokollen zu einer besseren Kontrolle der anterioren Gesichtshöhe beiträgt. Ziel dieser retrospektiven Kohortenstudie war es daher, die Auswirkung einer festsitzenden Behandlung mit Extraktion von 4 Prämolaren mit einer nichtextraktiven Behandlung auf die vertikale Dimension des Skeletts zu vergleichen.Eine konsekutive Stichprobe von 76 Kindern mit skelettaler Hyperdivergenz (49% männlich; Durchschnittsalter 11,9 Jahre) wurde in 2 Gruppen aufgeteilt, die entweder mit einer Nichtextraktionsbehandlung (n = 31) oder einer Extraktion von 4 Prämolaren (n = 45) behandelt wurden. Die Ausgangsdaten waren vergleichbar: Sagittale Frontzahnstufe 5,1 ± 2,5 mm, vertikale Frontzahnstufe 2,4 ± 1,9 mm, ANB-Winkel 4,6 ± 2,3° und SN-ML-Winkel 40,2 ± 3,5°. Die Patienten wurden mit festsitzenden Standardapparaturen mit „closing loops“ /Gleitmechanik behandelt. Die vertikalen skelettalen und die dentalen Resultate wurden auf lateralen Kephalogrammen vor und nach der Behandlung ermittelt. Die Ergebnisse wurden mit einer linearen Regression von 5% ausgewertet.Im Vergleich zu einer Behandlung ohne Extraktion hatte die Behandlung mit Prämolarenextraktionen keine signifikante Auswirkung auf den SN-ML-Winkel (Differenz [Δ] = 0,07°; 95%-Konfidenzintervall [KI] -0,90 bis 1,01°; p 0,88). Statistisch signifikante Veränderungen zwischen der Extraktions- und der Nichtextraktionsgruppe wurden nur für die Parameter SNA (Δ −1,47°; p = 0,003), ANB (Δ −1,17°; p = 0,004), SN-OP (Δ −1,48°; p = 0,04) und L1-ML (Δ −6,39°; p 0,001) festgestellt.Die kieferorthopädische Behandlung von Kindern mit skelettaler Hyperdivergenz durch systematische Extraktion von 4 Prämolaren hatte minimale Auswirkungen auf die vertikale Gesichtsdimension im Vergleich zu einer Behandlung ohne Extraktion.

Purpose Orthodontic fixed appliances have been proven to be effective in treating a wide variety of malocclusions, and different types of appliances have emerged during recent decades. However, the comparative effects of different appliances have not been adequately assessed. Thus, the aim was to assess the occlusal outcome of orthodontic treatment with preadjusted straight-wire (SWIRE) and standard edgewise (SEDGE) appliances. Methods In all, 56 patients (mean age: 13.5 years; 45% male) receiving extraction-based treatment with either SWIRE or SEDGE appliances were included. Between-group differences in the occlusal outcome assessed with the American Board of Orthodontists Objective Grading System (ABO-OGS) and treatment duration were analyzed statistically at the 5% level. Results The average ABO-OGS score was 31.3 ± 7.2 points and 34.0 ± 10.4 points in the SWIRE and SEDGE groups with no statistically significant difference between groups (P = 0.26). Treatment duration was significantly shorter in the SWIRE group compared to the SEDGE group, with an average difference of −6.8 months (95% confidence interval [95% CI] = −9.6 to −4.0 months; P P Conclusion Similar treatment outcomes were observed after premolar extraction treatment with SWIRE and SEDGE appliances. On the other hand, SEDGE appliances were associated with prolonged treatment duration and more visits needed to complete treatment compared to SWIRE appliances.

Purpose: To investigate marginal integrity of restorations applied with preheated and non- preheated composite, flowable composite, sonically activated composite, and a new thermo-viscous bulk-fill composite using near-infrared technology for preheating, in class V cavities of human molars. Materials and Methods: Standardized cavities were prepared on the buccal surfaces of 60 human mandibular molars and restored with one of the following resin composite materials after application of an etch-and-rinse adhesive (OptiBond FL, Kerr): non-preheated or preheated conventional composite (Filtek Supreme XTE, 3M Oral Care), preheated thermo-viscous composite (VisCalor bulk, V oco), soncially activated composite (SonicFill 3, Kerr), or flowable composite (Filtek Supreme XTE Flowable, 3M Oral Care) applied in bulk or as a lining material using the snow-plow technique. After light curing and polishing, the percentage of continuous margins (PCM) of the restorations in enamel and dentin was assessed using SEM both before and after thermomechanical loading (TML). TML was carried out with 3000 thermal cycles (5°C–50°C) and a simultaneous mechanical stress application with 1.2 million load-cycles (1.7 Hz, 49 N) in a computer-controlled masticator. Non-parametric statistical analysis was performed using Wilcoxon, Kruskal-Wallis, and Mann-Whitney U-tests (α = 0.05). Results: All groups revealed a significant decline in marginal integrity after TML in both enamel and dentin. Although the flowable group in enamel and the snow-plow group in dentin showed the highest PCM before TML, the differences between the groups were compensated after TML. Conclusion: All of the tested composites and application methods showed similar marginal integrities after thermomechanical loading and can be recommended for clinical implementation.

Selective laser melting has been increasingly used in the fabrication of metal-ceramic prostheses. The longevity of the prostheses depends on the strength of the metal-ceramic bond, which may differ with the framework manufacturing technique.The purpose of this in vitro study was to compare the bond strength of ceramic to cobalt-chromium (Co-Cr) alloys fabricated by different manufacturing methods.Sixty Ø15×2-mm disk-shaped specimens were prepared and assigned to 3 groups (n=20) with different manufacturing methods: milled Co-Cr (M), selective laser melted Co-Cr (SLM), and cast Co-Cr (C). The disks were ceramic layered with a 2-mm thickness. Half of the specimens from each group were thermocycled. The shear bond strength (SBS) test was applied to all specimens. The microstructure changes after ceramic layering were evaluated by X-ray diffraction (XRD). The specimens' surface morphology was analyzed by using scanning electron microscopy (SEM).Thermocycling had a significant effect on SBS values in the SLM group (P=.017). Considering the registered FThe adhesion strength of ceramic to Co-Cr differed with alloy composition and manufacturing technique. The aging process influenced the results in the SLM group.

Purpose The close topographic relationship between vascular and osseous structures in the condylar and subcondylar region and marked variability in the arterial course has been revealed by both imaging and cadaveric studies. This study aimed to verify the previously published information in a large sample and to determine a safe surgical region. Methods We analyzed the three-dimensional time-of-flight magnetic resonance angiography images of 300 individuals. Results The mean distance between the middle meningeal artery and the apex of the condyle or the most medial point of the condyle was 18.8 mm (range: 11.2–25.9 mm) or 14.5 mm (range: 8.8–22.9 mm) respectively. The course of the maxillary artery relative to the lateral pterygoid muscle was medial in 45.7% of cases and lateral in 54.3%. An asymmetric course was evident in 66 patients (22%). The mean distance between the maxillary artery and condylar process at the deepest point of the mandibular notch was 6.2 mm in sides exhibiting a medial course (range: 3.7–9.8 mm) and 6.6 mm in sides exhibiting a lateral course (range: 3.9–10.4 mm). The distances were significantly influenced by age, gender, and the course of the maxillary artery. Conclusion Our study emphasizes the marked inter- and intra-individual variability of the maxillary and middle meningeal arterial courses. We confirmed the proximity of the arteries to the condylar process. Extensive surgical experience and thorough preparation for each individual case are essential to prevent iatrogenic vascular injury.

Purpose The aim of the present study was to assess the perceptibility and acceptability threshold values for color differentiation at the restoration and mucosa levels. Materials and methods One restored single-tooth implant and the contralateral reference tooth were spectrophotometrically assessed in 20 patients. Perceptibility and acceptability were evaluated by dentists, dental technicians, and laypeople. Results Dental technicians had the highest sensitivity in the perception of tooth color differences (ΔE = 2.7), followed by dentists (ΔE = 3.3) and laypeople (ΔE = 4.4). Acceptability threshold values were generally higher than perceptibility threshold in all groups. Dental technicians exhibited the highest sensitivity in the perception of mucosa color differences (50% perceptibility at ΔE = 2.65), followed by dentists (ΔE > 3.7) and laypeople (ΔE > 6). Conclusion Color differences were tolerated with varying degrees among the three groups. Laypeople accepted higher color differences at the mucosa level.

Prosthetic rehabilitation in patients undergoing reconstructive surgery using vascularized free flaps is challenging, and functional rehabilitation of the patient with a fixed prosthesis is rare. Virtually planned maxillofacial reconstruction including simultaneous dental implantation according to the prosthodontic ideal position of the implants could further enhance dental rehabilitation. The data of 21 patients undergoing fibula free flap reconstructive surgery with CAD/CAM patient-specific reconstruction plates during the years 2015-2018 were analysed, including the applicability of the virtual plan, flap survival, duration of surgery, ischemia time, simultaneous dental implantation, implant exposure, and postoperative complications. The virtual plan could be translated to surgery in all cases. In total, 76 dental implants were simultaneously placed during primary reconstruction in the 21 patients. For 38.1% of these patients, the implants could be uncovered in secondary surgery; the mean duration until exposure was 7.6 months. The implant survival rate was 97.4% (74/76). Wound infection requiring a secondary intervention occurred in 23.8% of patients during follow-up. Virtually planned reconstruction with a fibula free flap, simultaneous dental implantation, and CAD/CAM plates allows early and functional dental rehabilitation. A dental workflow should be integrated into the virtual planning, and prosthetically favourable implant positions should determine the position of the fibula segments.

Purpose This study analyzed the radiologic outcomes of patients with unilateral mandibular condylar fractures treated with open reduction–internal fixation (ORIF) through a transoral approach. Patients and Methods In this retrospective study, the radiologic images of 40 patients who underwent open reduction–internal fixation through a transoral approach were presented to 2 independent examiners. All patients underwent the surgical procedure between January 2015 and December 2016 at the Department of Cranio-Maxillofacial Surgery at UniversitatsSpital Zurich and were included in a previous functional outcome study. The surgical results were analyzed and graded as poor, acceptable, or good. The examiners declared whether they would have made any intraoperative revisions if the radiologic information had been available. Finally, the examiners estimated the required duration of elastic intermaxillary fixation (IMF) from the radiologic images, which was compared with the actual duration. Results Fracture reduction was classified as good in 33 cases (82.5%), acceptable in 5 cases, and poor in 2 cases by one examiner and as good in 32 cases (80%), acceptable in 6 cases, and poor in 2 cases by the other examiner. The inter-rater reliability was determined to be good (Cohen κ = 0.92). Correct osteosynthesis placement was found in 19 cases by one examiner and in 21 cases by the other examiner, with good inter-rater reliability (κ = 0.8). Moderate inter-rater reliability (κ = 0.4) was found for the required duration of elastic IMF. Furthermore, the estimated elastic IMF duration matched the actual duration in fewer than half of the cases. Conclusions It is feasible to achieve reliably good radiologic results when operating on condylar process fractures by a transoral approach with endoscopic assistance and angled instruments. Intraoperative 3-dimensional imaging enables instant quality control and prompts surgical revision if needed.

OBJECTIVES: To observe the sequential healing of lateral onlay grafts in terms of volumetric and histological changes when using different combinations of synthetic soft-type block bone and resorbable collagen membranes. MATERIALS AND METHODS: A lateral onlay graft procedure was applied at the chronic narrow alveolar ridge of the mandible in 15 beagle dogs. The groups were allocated as follows: (a) empty control; (b) onlay graft using soft-type block bone 1 (hydroxyapatite [HA]: β-tricalcium phosphate [β-TCP] = 15:85) and a non-cross-linked collagen membrane (MP-BG group); (c) onlay graft using soft-type block bone 2 (HA:β-TCP = 60:40) and a non-cross-linked collagen membrane (OC-BG group); and (d) onlay graft using soft-type block bone 1 (HA:β-TCP = 15:85) and a cross-linked collagen membrane (MP-CM group). Volumetric and histomorphometric analyses were performed at 4, 8 and 16 weeks postoperatively. RESULTS: No clinical complications occurred in any of the groups. The OC-BG group showed significantly larger total augmented volumes than the control and MP-BG groups after 8 and 16 weeks. The areas of new bone were significantly larger in the OC-BG group than the other groups at 16 weeks. The horizontal thickness of the augmented ridge was significantly larger in the OC-BG group than in the control group at 16 weeks. CONCLUSION: The OC-BG group showed superior volume maintenance and osteogenic potential for up to 16 weeks compared to the other groups in an onlay graft model of the dog mandible despite the displacement of the bone graft.

Aim: To test whether or not buccal vertical bone dehiscences (≤5 mm) around posterior implants left for spontaneous healing (SH) result in the same clinical and radiologic outcome as dehiscences treated with guided bone regeneration (GBR) at 7.5 years after implant placement (IMPL). Materials and methods: Twenty-two patients receiving 28 posterior implants with a small non-contained buccal bone dehiscence (≤5 mm) were randomly assigned to the SH or the GBR group. Implants were loaded at 6 months. Clinical parameters (probing depths, sulcus bleeding index, plaque index) and approximal marginal radiographic bone levels were assessed regularly up to at least 6.8 years. The vertical extension of the dehiscences was measured clinically at IMPL and abutment connection and radiographically on cone beam computed tomographys at a mean follow-up time of 7.5 years. Results: Twenty patients with a total of 26 implants were recalled at 7.5 years (9.1% dropout). The implant/crown survival rates were 100% in both groups. Stable peri-implant tissues were observed in both groups showing only minimal signs of inflammation. During the entire study period (IMPL-7.5-year follow-up), the median buccal vertical bone gain measured 1.61 mm for the GBR group and 0.62 for the SH group showing no significant difference between the groups. Also, at 7.5 years, the median approximal marginal bone levels (GBR: 0.53; SH: 0.68) were not significantly different between the two groups (p = .61) while the remaining median buccal vertical dehiscences were larger in the SH group (2.51 mm) compared to the GBR group (1.66 mm; p = .02). Conclusions: Implants with small non-contained buccal bone dehiscences exhibited high implant survival rates and healthy peri-implant tissues at 7.5 years. In the GBR group, the buccal vertical bone levels were higher compared to the SH group but remained stable over the entire study period for both treatments. Keywords: bone substitute; dental implant; guided bone regeneration; small buccal defects; spontaneous healing. © 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The functionality of a new overdenture attachment (LOCATOR R-Tx) was described for different clinical situations: a conventional mandibular implant overdenture (IOD) retained by 2 implants, a straightforward chairside maintenance procedure for replacing a worn LOCATOR (Legacy) attachment with the new LOCATOR R-Tx, and a complex clinical situation with nonideal implant positions with compromised parallelism. The LOCATOR R-Tx is an advance on the existing LOCATOR Legacy attachment and has an improved abutment head design with a more durable surface coating to prevent attachment wear and thereby reduce frequency of maintenance.

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.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 (χAfter 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).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.

PURPOSE To evaluate image quality and diagnostic accuracy of buccal bone thickness assessment in maxillary and mandibular anterior region using cone-beam computed tomography (CBCT) and 3-dimensional double-echo steady-state (DESS) MRI for preoperative planning of immediate dental implants in healthy individuals. METHODS One hundred and twenty teeth in 10 volunteers were retrospectively evaluated for image quality and artifacts using Likert scale (4 = excellent to 0 = decreased). Buccal bone thickness was measured at three measurement points (M1 = 2 mm from the cementoenamel junction, M2 = middle of the root, and M3 = at the root apex) for each tooth in the maxillary (13-23) and the mandibular anterior region (33-43). Descriptive statistics and two-way ANOVA with Tukey's Post-hoc test were performed to evaluate the significant differences (α = 0.05) between both imaging modalities. RESULTS Image quality showed little to no artifacts and enabled confident diagnostic interpretation (CBCT (3.72 ± 0.46); MRI (3.65 ± 0.49)), with no significant differences between both imaging modalities (p > 0.05). Regarding the assessment of buccal bone thickness at M1-M3 for the teeth 13-23 and 33-43, no significant differences were noted (p > 0.05). MRI demonstrated slight, nonsignificant overestimation of thickness with the canines having mainly a thick buccal bone wall, where thin buccal wall was evident for the central incisors. CONCLUSION Black bone MRI sequences, such as 3D-DESS MRI, for immediate implant planning provided confidential diagnostic accuracy in bone thickness assessment without significant disadvantages compared to CBCT. Thus, the implementation of no-dose protocols for dental rehabilitation using an immediate loading approach seems promising and could further improve the treatment strategy for dental rehabilitation.

OBJECTIVE The aim of this study was to compare the mechanical properties of orthodontic aligners among different commercially available 3D printing devices. MATERIALS AND METHODS Five 3D printers (Ka:rv LP 550, Swinwon; "KAR"), (L120, Dazz 3D; "L12"), (MiiCraft 125, Miicraft Jena; "MIC"), (Slash 2, Uniz; "SLS") and (Pro 95, SprintRay; "PRO") were used to prepare orthodontic aligners with dental resin (Tera Harz TC-85DAW, Graphy). The central incisors of each aligner were cut, prepared and evaluated in terms of Martens-Hardness (HM), indentation-modulus (EIT ) and elastic-index (ηIT ) as per ISO14577-1:2002. Force-indentation curves were recorded and differences among printers were checked with generalized linear regressions (alpha=5%). RESULTS Statistically significant differences were seen for all mechanical properties (P

Abstract Purpose of Review Graphene is introduced in dentistry as a material to be used in the fabrication or coating of dental implants due to its biocompatibility, ability to physically interact with biomolecules and very high surface area. This review highlights the current knowledge on the general properties of graphene, potential benefits especially when used in zirconia-based implants, as composite materials and coatings. Recent Findings The literature reviewed showed a growing body of evidence supporting the use of graphene-based material, associated with titanium or zirconia as a coating or composite material that helps in cell viability, differentiation and proliferation, improving the bioactivity, osseointegration, physical, chemical and mechanical properties particularly zirconia. Graphene-based materials present great potential for biomedical applications especially when used in the form of nanostructured biological coatings that can be obtained through reproducible and economical processes. Summary The use of graphene as a composite implant material or coating may have great potential for osseointegration and bone regeneration, providing that, features including hydrophilicity, protein adsorption capacity, oxygen content and effect of external parameters such as temperature, pH and ionic strength need further elucidations before they can be implemented as a coating or composite material for dental implants.

Although the intraoral scanning of edentulous ridges is feasible, clinical evidence that the resulting denture retention is equivalent to that achieved with conventional impressions is lacking.The purpose of this clinical study was to determine the retention of complete denture bases fabricated from digital intraoral scans versus conventional impressions by using border molding and posterior palatal seal compression.Twenty volunteers with an edentulous maxilla were recruited. An intraoral scan of the maxilla and a conventionally border-molded impression with a custom tray were made. The conventional impression was poured; the definitive cast was scanned. Three-dimensionally (3D) printed (PB1) and milled bases (MB1) were fabricated based on the scan of the definitive cast. Based on the intraoral scan, a 3D-printed (PB2) and a milled base (MB2) were fabricated. On each base, a platform with a hook consisting of a central notch orienting the force against the post dam (PD) and 2 lateral notches orienting the forces against the left (LT) and right (RT) tuberosities was set in the center of the outer surface of the base. A traction dynamometer was inserted in the hook and oriented into the corresponding notch by applying force until dislodgement. All bases were subsequently stored in artificial saliva for 2 weeks and scanned. Retention testing was repeated by using the same procedure. To evaluate trueness and to visualize the differences on a color map, the scan of the definitive cast and the intraoral scans were matched and compared in 3 dimensions. The Wilcoxon tests were used to compare the retention of the different bases (95% confidence interval, α=.05).Nineteen participants with a mean ±standard deviation age of 64.1 ±14.7 years completed the 4 study sessions. The retention of printed bases (PD: 16.08 ±15.28 N; LT: 14.98 ±14.72 N; RT: 11.28 ±9.57 N) and milled bases (PD:14.52 ±17.07 N; RT: 11.99 ±12.10 N; LT: 13.55 ±15.53 N) fabricated from conventional impressions presented significantly higher retentive forces than those printed (PD: 6.21 ±4.72 N; RT:5.12 ±2.78 N; LT: 4.45 ±2.77 N) and milled (PD: 6.58 ±4.92 N; RT: 4.65 ±2.63 N; LT: 5.02 ±3.58 N) from the intraoral scans (P.05). The differences were significant in all directions of dislodgement, as well as after storage in artificial saliva for 2 weeks. Comparison of the 3D distances between the intraoral scan and the definitive cast revealed a mean deviation of 0.45 ±0.11 mm.Conventional impressions of the edentulous maxilla, including the clinical steps of border molding and posterior palatal seal compression, provide better retention than digital intraoral scans with both milled and 3D-printed denture bases.

The purpose of this investigation of untreated monozygotic and dizygotic twins was to identify the genetic and environmental components to the facial soft tissue growth.The sample consisted of 52 untreated monozygotic twins (36 male and 16 female) and 46 untreated dizygotic twins (23 male and 23 female) from the Forsyth Moorrees Twin Study (1959-1975).Lateral cephalograms were taken at 12 and 17 years of age and traced to analyse facial convexity, nasolabial angle, upper and lower lip thickness, upper and lower lip profile and nose prominence. The genetic and environmental components of variance were analysed with structural equation modelling for multilevel mixed-effects model.At 12 years of age, strong additive genetic influence was seen for facial convexity (70%), upper lip profile (66%) and nose prominence (65%), whereas strong dominant genetic components were found for upper lip thickness (56%). Nevertheless, under unique environment influence were nasolabial angle (58%), lower lip profile (51%) and lower lip thickness (64%). At 17 years of age, only upper lip thickness (55%) and nose prominence (84%) were under strong additive genetic control, while the rest of the variables were under strong dominant genetic control. The only exception was lower lip thickness (61%), which is still influenced by the unique environment.Although monozygotic/dizygotic twins share at least part of their genome, at both times either additive, dominant or environmental components were found. Nevertheless, at 17 years of age most of the variables are either under additive or dominant genetic influence.

OBJECTIVES To identify the 10 most numerically prolific authors publishing in the field of orthodontics for each year over the last decade (2011-2020), describe the characteristics of these outputs and identify trends in the types of study being published. MATERIALS AND METHODS A Scopus literature search was conducted to identify the 10 most numerically prolific publishing authors in orthodontics for each year during this decade. Number and characteristics of all publications for each author were analysed with descriptive and inferential statistics. RESULTS Forty-nine different individual authors were identified who were collectively prolific for between 1-8 years within the assessment decade. These authors published a total of 2025 papers, with a median annual output of 18 papers per year; however, half of these authors published between 15-24 papers per year (range 5-200). Amongst authors, 2 or more collaborated on only 7% of the identified papers. The median number of authors per paper was 5 (range 1-27) with significant variation according to study design (P

The aim of thisFive IOSs (Medit i500, Omnicam, Primescan, Trios 3, Trios 4) were used to digitize the reference model, which represented a simplified full-arch situation with four abutment teeth. Each IOS was used five times by an experienced operator, resulting in 25 STL (Standard Tessellation Language) files. STL data were imported into 3D software (Final SurfacePrimescan (matching error value: 0.015), Trios 3 (0.016), and Trios 4 (0.018) revealed comparable results with significantly higher accuracy compared to Medit i500 (0.035) and Omnicam (0.028) (The novel reference model investigated in this study can be used to assess the performance of dental scanning technologies in the daily routine setting and in research settings.

To assess long-term outcomes of implants placed in conjunction with guided bone regeneration (GBR) with or without recombinant human bone morphogenetic protein-2 (rhBMP-2).Eleven patients with at least two lateral bone defects (split-mouth design) received a total of 34 implants. The defects were treated with a xenogenic bone substitute with (test) or without (control) rhBMP-2 and covered with a collagen membrane. Eight patients could be reexamined after at least 17 years. Wilcoxon signed-rank tests were performed to assess differences between test and control groups.The implant survival rate was 100% for all test and control sites. Mean marginal bone levels were 2.51 mm (SD ±1.64) (mesial test), 1.83 mm (SD ±0.93) (mesial control) (p = .055), 2.36 mm (SD ±1.70) (distal test), and 2.13 mm (SD ±0.84) (distal control) (p = 1.000). Compared with the mean values at baseline, a mean bone loss of 1.16 mm (SD ±1.60) (test) and 0.70 mm (SD ±1.02) (control) was found. The mean buccal bone gain after 17 years was 5.38 mm (test) and 3.14 mm (control) based on the comparison between the measurements at the cone beam CT after 17 years and the data from the intraoperative measurements at baseline. Further, mean values for (i) bone thickness ranged from 1.36 to 3.09 mm (test) and 1.18 to 3.39 mm (control) and for (ii) mucosal thickness of 1.24 mm (test) and 1.26 mm (control).Implants placed in conjunction with GBR applying a xenogenic bone substitute and a collagen membrane with and without the addition of rhBMP-2 demonstrate excellent clinical and radiographic results after at least 17 years.

Objectives: Mandibular anterior crowding can be treated by expanding the dental arch or by extracting teeth, usually premolars. The aim of this study was to assess long-term outcomes of extraction versus non-extraction therapies in terms of gingival recession. Methods: Fifty consecutive patients were selected, including 26non-extraction and 24extraction cases. All had been treated with fixed appliances because of well-defined comparable moderate crowding and Angle ClassI malocclusion. Patient age was documented before treatment, upon debonding, and during retention, thus, allowing the calculation of the duration of active treatment and retention. The records available for these three points in time included casts and cephalograms. The casts were used to quantify mandibular anterior crowding and the associated clinical crown lengths. Based on the cephalograms, a number of symphyseal variables were measured. Data analysis included descriptive statistics, correlation tests, and multiple regressions. Results: For accurate comparison of the extraction and non-extraction treatment groups, we required and verified that no significant intergroup differences were present with regard to initial crowding, duration of retention, and age at final record-taking. Both groups revealed increases in crown length, which fell short of statistical significance but were twice as large for canines than for incisors. The treatment decisions to extract premolars did result in significantly different topographic positions of the lower incisors, but they made no difference in the recession outcomes. None of the variables in our regression analysis was found to predict gingival recession. Conclusion: Findings of gingival recession in patients having undergone orthodontic treatment do not seem to be related to extraction/non-extraction treatment decisions.

OBJECTIVES: The task of working Group 2 at the 6th Consensus Meeting of the European Association for Osseointegration was to comprehensively assess the effects of soft tissue augmentation procedures at dental implant sites on clinical, radiographic and patient-reported outcome measures (PROMs) including an overview on available outcome measures and methods of assessment.MATERIALS AND METHODS: Three systematic reviews and one critical review were performed in advance on (i) the effects of soft tissue augmentation procedures on clinical, radiographic and aesthetic outcomes, (ii) reliability and validity of outcome measures and methods of assessment and (iii) PROMs applied in clinical studies for soft tissue augmentation procedures at dental implant sites. Major findings, consensus statements, clinical recommendations and implications for future research were discussed in the group and approved during the plenary sessions.RESULTS: The four reviews predominantly revealed: Soft tissue augmentation procedures in conjunction with immediate and delayed implant placement result in superior aesthetic outcomes compared to no soft tissue augmentation in the zone of aesthetic priority. Soft tissue augmentation procedures have a limited effect on marginal bone level changes compared to implant sites without soft tissue augmentation. Clinically relevant parameters (gingival index, mucosal recession) and plaque control improve at implant sites when the width of keratinised mucosa is increased. A variety of aesthetic indices have been described with good reliability. Pink Esthetic Score and Complex Esthetic Index are the most validated aesthetic indices for single implants, though. Superimposed digital surface scans are most accurate to assess profilometric tissue changes. PROMs following soft tissue augmentation procedures have been assessed using various forms of questionnaires. Soft tissue augmentation had a limited effect on PROMs.CONCLUSIONS: Soft tissue augmentation procedures are widely applied in conjunction with implant therapy. Depending on the indication of these interventions, clinical, radiographic and aesthetic outcomes may improve, whereas the effect on PROMs is limited.

PURPOSE To assess the clinical outcomes of single-retainer resin-bonded fixed dental prostheses (RBFDPs) and the profilometric changes of pontic sites after a mean of 10 years in function. MATERIALS AND METHODS Ten patients (mean age 32.4 years) who had received an RBFDP replacing a single anterior tooth were recalled after 10 years. Five patients had received a subepithelial connective tissue graft (SCTG) at the pontic site. The clinical assessment comprised the following parameters: probing depth, bleeding on probing, modified plaque control record, gingival recession, measurement of the width of keratinized mucosa, and intraoral photographs and radiographs. The modified criteria of the United States Public Health Services evaluation system were applied. Additionally, patient satisfaction was recorded. Data were analyzed descriptively, and the 10-year RBFDP survival rates were calculated using Kaplan-Meier analysis. RESULTS The RBFDP survival rate after a mean follow-up of 10.0 years (range 7.4 to 13.3 years) was 100%. Neither technical failures nor biologic complications were observed. All abutment teeth remained vital, and no secondary caries were detected. Between baseline and follow-up examinations, the profilometric changes at the pontic sites were minimal, exhibiting a loss of -0.03 ± 0.10 mm (no SCTG) and 0.00 ± 0.37 mm (SCTG). CONCLUSION The present study exhibited high survival rates and low complication rates of the restorations, as well as excellent profilometric stability of the pontic sites over 10 years. The use of an RBFDP is a viable long-term treatment option for replacing a single anterior tooth.

Statement of problem: Studies on the microhardness of novel additively manufactured polymers compared with well-established low- and high-viscosity composite resins with regard to chemical composition are lacking. Purpose: The purpose of this in vitro study was to evaluate the effect of hydrothermal aging on the microhardness of various conventional and additively manufactured polymers. Material and methods: Cylindrically shaped specimens (N=240, n=10 per group) (Ø10×2 mm) were either additively manufactured (6 groups) or conventionally (6 groups) manufactured by using 3D (Optiprint Temp [OP; Dentona]; C&B MFH [ND; NextDent]; Saremco print CROWNTEC [SA; Saremco Dental AG]; Temp Print [TP; GC]; 3DELTA ETEMP [DM; Deltamed]; MED690 [ST; Stratasys, Ltd]) or conventional low (Gradia Direct [GR; GC]; Clearfil Majesty [CM; Kuraray Noritake]; Tetric EvoCeram [TE; Ivoclar Vivadent AG]) and high (Gradia Direct Flo [GR-F; GC]; Clearfil Majesty Flow [CM-F; Kuraray Noritake]; Tetric EvoFlow [TE-F; Ivoclar Vivadent AG]) viscous materials. All specimens were randomly allotted to 2 different aging methods (no-aging [dry] or aging by thermocycling [TC], ×6000, 5 °C-55 °C) and Vickers hardness (VH) tested (ZHV30; Zwick). Three indentations were made on each specimen (0.98-N load, duration 15 seconds). The calculated average microhardness value of each specimen was statistically analyzed by using 2-way ANOVA and Tukey post hoc tests (α=.05). Two-parameter Weibull distribution was calculated to predict the reliability of material type and aging method on VH. Results: The mean ±standard deviation VH ranged between 17 ±0.5 VHN and 68 ±0.5 VHN in the following ascending order: group STab, NDbc, TPcd, GR-Fde, TE-Fefgh. The groups with the same superscript were not significantly different from each other (P>.05). The mean ±standard deviation of HV for aged (37 ±1 VHN) and nonaged (35 ±1 VHN) specimens were statistically similar (P>.05). The Weibull distribution values presented the highest shape for the aged group SA (37.81). Conclusions: The choice of the material had a significant effect and resulted in lower hardness for the 3-dimensionally printed materials than for the conventional composite resins. Under fatigue conditions, the choice of the material showed no significant difference when the Vickers microhardness was evaluated.

STATEMENT OF PROBLEM Interim dental restorations can be fabricated from additively manufactured ingots. However, the flexural strength and surface roughness of restorations fabricated by using this technique are unknown. PURPOSE The purpose of this in vitro study was to assess the influence of the manufacturing method (milling, additive manufacturing, or a combination of subtractive and additive methods) and accelerating aging on the flexural strength and surface roughness of interim dental materials. MATERIAL AND METHODS A bar design (25×2×2 mm) was used to fabricate the specimens by using 3 methods: milling (M group), additive manufacturing (AM group), and a combination of subtractive and additive methods (AM+M group). In the M group, an interim material (CopraTemp PMMA) was used to fabricate the milled (350i imes-icore) specimens. In the AM group, specimens were fabricated by using a printer (Form3B+) and an interim resin (Temporary CB) according to the manufacturer's protocol. In the AM+M group, specimens were milled from AM ingots (Temporary CB) and with the same milling machine as in the M group. Two subgroups were created based on the artificial aging (thermocycling): nonaged and aged (n=10). Flexural strength was calculated by using a universal testing machine, followed by determination of the Weibull distribution. Surface roughness was measured by using a digital microscope. The Shapiro-Wilk test revealed that the flexural strength and surface roughness (Ra) data were normally distributed (P>.05). Two-way ANOVA followed by post hoc multiple comparison Tukey tests were used to examine the data (α=.05). The Shapiro-Wilk test revealed that the surface roughness area data were not normally distributed (P

AIM The aim was to evaluate the performance of implants placed with simultaneous guided bone regeneration (GBR) using resorbable or nonresorbable membranes compared to implants placed in pristine bone without bone regeneration after an observation period of 22-24 years. MATERIAL AND METHODS The patient cohort of this clinical trial was treated from 1994 to 1996. Dehiscence defects were treated with GBR by either using resorbable collagen membranes (BG) or nonresorbable ePTFE membranes (GT). Implants placed in pristine bone served as a control (CT). Clinical parameters, marginal bone levels, and technical outcomes were evaluated following restoration placement and at the present follow-up. A 3D radiographic analysis was conducted in order to assess buccal and oral bone dimensions. Implant survival was assessed with Kaplan-Meier analysis and a frailty model (level of significance 5%). RESULTS Out of the originally 72 patients (mean age 75.4 ± 15.70 years) with 265 implants, 39 patients with 147 implants were included in the study after a median period of 23.5 years. Implant survival was 89.3% in group BG (n = 100), 90.2% in group GT (n = 37), and 93.8% in group CT (n = 105), without significant differences (Frailty proportional hazard model p = .79). Smoking had a negative effect on survival (p = .0122). Mean vertical marginal bone levels were -2.3 ± 1.4 mm (BG, n = 59), -3.0 ± 1.5 mm (GT, n = 21), and -2.3 ± 1.6 mm (CT, n = 52). The vertical buccal bone levels were -3.0 ± 1.9 mm (BG, n = 57), -3.5 ± 2.2 mm (GT, n = 21), and -2.6 ± 1.8 mm (CT, n = 49), without significant differences. CONCLUSION Implant placement with GBR procedures provides treatment outcomes with favorable implant survival rates (89.3%-93.8%) after 23.5 years. Smoking, however, affected implant survival negatively.