Prospective clinical-radiological study of the survival and behavior of short implants.

STATEMENT OF PROBLEM: Short implants are a therapeutic alternative for edentulous patients with severe bone resorption. Differences in peri-implant bone loss and complications of short implants depending on the type of connection are unclear. PURPOSE: The main purpose of this clinical study was to evaluate the survival rate after 2 years of the short implants in the Oxtein system (Proclinic). Secondary objectives were to compare implant survival, peri-implant bone loss, peri-implant mucosal status, and associated complications in internal hexagonal connection versus external hexagonal connection implants. MATERIAL AND METHODS: A randomized clinical trial was carried out in 14 patients with a mean age of 62.7 ±8.5 years, with a total of 61 Oxtein L35 and L6 Proclinic implants being placed at the Faculty of Dentistry. A descriptive analysis, simple binary logistic regression model using generalized estimating equations. and Kaplan-Meier survival analysis were carried out (α=.05). RESULTS: Implant survival was 85.2% (52/61). Failure of all implants occurred before prosthetic loading; bleeding after probing occurred in 28 implants, being greater among external connection implants (57.6%) P=.025. The presence of plaque appeared in 36 of the implants, without statistically significant differences between external connection (72.8%) and internal connection (60.0%) (P>.05). A total of 28 implants had at least 2 mm of keratinized mucosa, without statistically significant differences between external connection (63.6%) and internal connection (35.0%) P=.200. A total of 8 complications (13.1%) were recorded, including connection fractures, screw fracture, framework fracture, and buccal fenestrations. CONCLUSIONS: Short implants are a therapeutic solution to more complex surgical techniques. However, as lower survival has been reported, the characteristics of the implants and operator experience are important factors for their success.

Outcome measurements and quality of randomized controlled clinical trials of tooth-supported fixed dental prostheses: A systematic review and qualitative analysis.

STATEMENT OF PROBLEM: The lack of consensus regarding a standardized set of outcome measurements and noncompliance with current reporting guidelines in clinical trials of tooth-supported fixed dental prostheses (FDPs) hamper interstudy comparability, compromise scientific evidence, and waste research effort and resources in prosthetic dentistry. PURPOSE: The primary objective of this systematic review was to identify all primary and secondary outcome measurements assessed in randomized controlled trials (RCTs) of tooth-supported FDPs. Secondary objectives were to assess their methodological quality by using the Cochrane Collaboration's risk of bias tool (RoB, v2.0) and their reporting quality by means of a standardized 16-item CONSORT assessment tool through published reports. MATERIAL AND METHODS: An electronic search was conducted in MEDLINE, EMBASE, and Cochrane library to identify all RCT-related articles published in the past 10 years. Differences in RoB were tested with the Pearson chi-square test, and those in CONSORT score with the Student t test. RESULTS: A total of 64 RCTs from 79 publications were deemed eligible. The diversity of outcome measures used in the field is apparent. Twenty percent of the included studies had a low RoB, 79% showed some concerns, and 1% had a high RoB. The mean ±standard deviation CONSORT compliance score was 22.56 ±3.17. Trials adhered to the CONSORT statement reported lower RoB than those that did not adhere (P<.001). RCTs with a low RoB reported more comprehensive adherence to CONSORT guidelines than those with some concerns (MD 4 [95% CI 1.52-6.48]; P=.004). CONCLUSIONS: A standardized core outcome reporting set in clinical research on tooth-supported FDPs remains evident. Adherence to the CONSORT statement continues to be low, with some RoB concerns that can be improved.

Changes in the teaching of prosthodontics adopted in the last academic course of the degree in dentistry in Spain during the first period of the COVID-19 pandemic.

OBJECTIVES: To investigate the impact of the COVID-19 pandemic in the teaching of prosthodontics, on the 5th course of the Bachelor's degree in Dentistry in Spain. METHODS: In June 2021, a two-section survey was submitted to the coordinators of prosthodontics of the 23 Spanish faculties of Dentistry. The first section was focused on the theoretical lessons, seminars, and clinical discussion sessions. The second part relied on the clinical teaching and the implemented preventive measures. RESULTS: The response rate was 100%. By the end of the 2020-21 course, both the theoretical and practical teaching were replaced by online activities, returning to face-to face in 2021-22. While most participants preferred in-person seminars and clinical discussion sessions, concerning the theory, comparable percentages of professors chose either face-to-face or blended learning (BL). The students' satisfaction with BL is high, but they seem more attentive in-person. At the beginning of the pandemic, the most common emergency in prosthodontics was debonding. Overall, a low concern about cross-infection was noticed. The barrier measures were the mainly adopted for prevention. CONCLUSIONS: Although the BL is appreciated in prosthodontics for theoretical lessons, face-to-face teaching appears to be the best option for seminars and clinical case discussions. The students are satisfied with BL. CLINICAL SIGNIFICANCE: In the face of the COVID-19 pandemic, the Spanish faculties of Dentistry responded quickly to continuing offering quality education through an accelerated digitization process that has created a new paradigm. Detailed analyses of these changes may help establish plans to respond systematically to unforeseen emergencies.

'Thermo-mechanical behavior of alternative material combinations for full-arch implant-supported hybrid prostheses with short cantilevers'.

OBJECTIVES: To compare the fracture resistance (FR) of three combinations of materials for full-arch maxillary implant-supported hybrid prostheses (HPs) with short cantilevers (≤ 10 mm). METHODS: Maxillary HPs were fabricated and classified as follows (n = 5 each): Group-1 (CC-A, control): acrylic-resin-veneered Co-Cr frameworks; Group-2 (CF-A): acrylic-resin-veneered carbon-fiber mesostructures; and Group-3 (CF-R): composite-resin-veneered carbon-fiber frames. Specimens were thermal-cycled (5,000 cycles; 5 °C-55 °C; dwell time: 30 s). Vertical loads were applied until failure, first at the 10-mm-long cantilever (LC), and, afterwards, at the anterior region (AR), using a universal testing machine (crosshead speed: 0.05 mm/s). The fracture pattern was assessed by stereomicroscope and SEM. The one-way ANOVA, the Bonferroni, and the independent samples t tests, were run (α= 0.05). RESULTS: At LC, CF-A, and CC-A samples exhibited the highest FR values (p< 0.001), showing no differences to each other. At AR, CC-A specimens recorded the highest FR, followed by CF-A samples (p< 0.001). CF-R HPs displayed the lowest FR at both locations (p< 0.001). The only group with differences between the tested sites was the CC-A, the AR being more resistant (p< 0.001). Most CC-A and CF-A HPs failed cohesively. CF-R prostheses mainly failed adhesively. CONCLUSIONS: Maxillary HPs with short cantilevers (≤ 10 mm) made of Co-Cr or carbon-fiber veneered with acrylic resin demonstrated an adequate mechanical resistance (> 900 N). CLINICAL SIGNIFICANCE: For maxillary HPs with cantilevers up to 10 mm, acrylic-veneered carbon- fiber mesostructures may be recommended, whereas coating carbon-fiber frames with composite resin seems not suitable.

Influence of Splint Support on the Precision of Static Totally Guided Dental Implant Surgery: A Systematic Review and Network Meta-analysis.

Purpose: To assess the accuracy of totally guided implant placement with static surgical splints in relation to the different types of supporting tissues (tooth, mucosa, or bone). Materials and Methods: This review was carried out following the PRISMA guidelines. An electronic search was done of the MEDLINE (PubMed), Embase, and Cochrane Library databases, without publication year or language restrictions. Results: The literature search yielded a total of 877 articles; 18 were included in the qualitative synthesis, and 16 of these articles were included in the quantitative analysis. The included studies presented a high risk of bias, except for one randomized clinical trial. The strength of the recommendations is therefore weak. In the angular deviation treatment, statistically significant differences were observed in the accuracy of the implants with tooth vs bone support: Bone support yielded 1.31 degrees greater deviation vs tooth support (SD = 0.43; 95% CI: 0.47, 2.15, P = .002). No significant differences were observed in the linear deviations. Conclusion: Tooth support proved to be significantly more precise than bone support splints. There were no differences referring to horizontal coronal deviation, horizontal apical deviation, or vertical deviation according to the type of splint support used.

Fracture resistance of cantilevered full-arch implant-supported hybrid prostheses with carbon fiber frameworks after thermal cycling.

OBJECTIVES: This in vitro study aimed to find the best combination of mesostructure and veneering materials for full-arch implant-supported hybrid prostheses (HPs) in terms of the fracture resistance (FR) of their cantilevers. METHODS: Three groups (n = 5 each) of maxillary HPs were fabricated: Group-1 (CC-A, control): Co-Cr frameworks coated with acrylic resin; Group-2 (CF-A): carbon fiber veneered with acrylic resin; and Group-3 (CF-R): carbon fiber coated with composite resin. All specimens were submitted to 5,000 thermal cycles (5 °C - 55 °C, dwell time: 30 s), and subjected to a single cantilever bending test in a universal testing machine (crosshead speed: 0.5 mm/min) until failure. The fracture pattern was assessed using stereo microscope and SEM. The one-way ANOVA and Bonferroni tests were run (α= 0.05). RESULTS: The FR yielded significant differences among the three groups (p< 0.001). CC-A samples reached the highest FR values (p ≤ 0.001), whereas both CF-A and CF-R HPs exhibited the comparably (p = 0.107) lowest FR. CC-A specimens failed cohesively (100%): mostly without chipping (80%). CF-A mesostructures were always broken at the connections of the distal implants. CF-R prostheses often failed adhesively (80%). CONCLUSIONS: The HPs made of Co-Cr veneered with acrylic demonstrated the best mechanical behavior, being the only group whose 13-mm long cantilevers exceeded the clinically acceptable FR of 900 N. The HPs constructed with carbon fiber frameworks showed, additionally, more unfavorable fracture patterns. CLINICAL SIGNIFICANCE: For HPs with cantilevers up to 13 mm, Co-Cr mesostructures coated with acrylic may represent the optimum combination of materials.

Accuracy of a guided implant system with milled surgical templates.

PURPOSE: This in vitro study analyzed the accuracy of a computer-assisted design (CAD)/computer-assisted manufacturing (CAM) guided implant surgery system by comparing linear, angular, and coronal deviations between the planned and final implant placement. METHODS: By using a fully guided surgery workflow, 32 dental implants were placed in 16 partially edentulous models. After virtual design of the restorations, radiological and CAD files were matched and implant positions were planned by using dedicated implant planning software (Galileo Implant version 1.9.2.). Templates were designed (Cerec Omnicam) and milled (Cerec MC XL) by using chairside workflow. Galileo Implant version 1.9.2. was used to evaluate accuracy. RESULTS: Mean horizontal and angular-coronal total deviation values were 0.2 mm (SD = 0.126) and 1.1º (SD = 0.834) respectively. Multivariate analysis of variance showed significant differences in horizontal and angular-coronal total deviation in the 32 implants (P = 0.0001). Multivariate analysis with one-factor interaction showed no statistical difference in implant position or implant type (P = 0.139) between eight maxilla models and eight jaw models. CONCLUSION: Horizontal and angular-coronal deviations of implants placed with chairside digital workflow were within the recommended safety margin for fully guided surgery.

Zirconia-ceramic versus metal-ceramic posterior multiunit tooth-supported fixed dental prostheses: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The authors aimed to compare the survival and complication rates of zirconia-ceramic (ZC) versus metal-ceramic (MC) restorative material in multiunit tooth-supported posterior fixed dental prostheses (FDP). TYPES OF STUDIES REVIEWED: The authors conducted a systematic search of randomized controlled trials (RCTs), with no time or language restrictions, up to May 2019 using the MEDLINE (PubMed), Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases, followed by a manual search. RESULTS: The authors included 7 RCTs in the review and 5 RCTs in the meta-analysis. All studies had a low risk of bias. The authors included 330 participants (177 ZC and 173 MC tooth-supported FDP) in the meta-analysis, which revealed a medium-term survival rate of 95.4% (95% confidence interval [CI], 90.5% to 99.1%) for ZC FDP compared with 96.9% (95% CI, 94.3% to 99.4%) for MC FDP, with no significant differences (P = .364). The biological or technical complications did not show statistically significant differences, except in the global ceramic veneering chipping analysis (P = .023; risk difference [RD], 22.3%; 95% CI, 3.0% to 41.6%) and their subanalysis: minor chipping or chipping that can be solved with polishing (P = .044; RD, 19.5%; 95% CI, 0.5% to 38.4%), and major chipping or chipping that needs repair in the laboratory (P = .023; RD, 6.0%; 95% CI, 0.8% to 11.3%). CONCLUSIONS AND PRACTICAL IMPLICATIONS: Posterior multiunit ZC restorations are considered a predictable treatment in the medium term, although they are slightly more susceptible to chipping of the veneering ceramic than MC restorations.