Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry最新文献

A technique is described to obtain a 3D-printed custom tray for complete dentures through open-source, free software and additive manufacturing. This approach enables the production of custom trays in a cost-effective and optimized manner. A three-dimensional (3D) digital cast is obtained by photogrammetry and later used to design a digital custom tray. Then, the digital custom tray is manufactured by a 3D printer to be used in clinical procedures. This technique is a clean, rapid, and low-cost alternative to the traditional technique.

Purpose: The cement interface is particularly important for successful zirconia-titanium base (Ti-base) restorations, as retention relies primarily on adhesive bonding. The aim of this in vitro study was to assess and compare the influence of a universal resin cement used with either a self-adhesive or adhesive bonding protocol versus adhesive resin cements on the retention of zirconia to Ti-base abutments, with and without autoclaving.

Materials and methods: Zirconia buildups were cemented to titanium-base abutments using RelyX Universal (RXU) as a self-adhesive resin cement, RXU with a primer (RXU/SUP), Panavia V5 (PV5) with primer, or multilink hybrid abutment (MHA) with primer. Half of the specimens were autoclaved. Push-out testing was performed, and data were statistically evaluated using the analysis of variance (ANOVA), Tukey honest significant difference test, and family-wise error rate method.

Results: Of the nonautoclaved groups, RXU/SUP showed the highest initial mean push-out load (1576.45 ± 195.86 N), followed by MHA (1268.10 ± 160.67 N), RXU (959.66 ± 139.24 N), and PV5 (905.84 ± 298.38 N). Autoclaving did not have a significant influence on cement push-out load when compared directly within cement pairs. The push-out load of RXU used as self-adhesive cement was similar to PV5 with primer. Retention of RXU/SUP and MHA groups was significantly higher than that of RXU or PV5.

Conclusion: In this in vitro study, RXU performed as well as PV5 groups and required the fewest preparation steps, suggesting it may be a good option for improving workflow efficiency. Results indicated a marginally positive effect of autoclaving between pairs, however, it was not significant.

Purpose: The purpose of this study was to evaluate the survival outcomes of dental implants placed in the pterygoid region and assess the potential influence of multiple clinical variables on their survival.

Materials and methods: A retrospective chart review was conducted on pterygoid implants placed over a 9-year period at the University of Connecticut Department of Prosthodontics. All pterygoid implants were placed by a single board-certified prosthodontist following a standardized surgical protocol. The implants were restored by various clinicians during the 9-year period. Data collected included implant size and type, loading protocol, surgical and prosthetic complications, patient gender, presence of parafunctional habits, and type of opposing dentition. A life table was used to calculate interval survival rates (ISR) and cumulative survival rates (CSR) of pterygoid implants.

Results: A total of 102 pterygoid implants placed in 69 patients (32 males, 37 females) were eligible for this retrospective study. The mean follow-up time was 34.35 months. A total of five implant failures were observed, resulting in a cumulative survival rate of 94.74%. All implant failures occurred within the first 4 to 5 months following implant placement and prior to any functional loading, suggesting a failure to achieve osseointegration. No intraoperative complications were noted, and only one postoperative surgical complication was observed, which was successfully managed without further issue.

Conclusions: Roughened surface implants placed in the pterygoid region offer favorable implant survival of 95% with minimal complications.

Purpose: This study aimed to evaluate the inherent and after cyclic loading fracture strength of implant-supported cantilevered fixed prostheses fabricated from recently introduced additively manufactured (AM) and subtractively manufactured (SM) materials, considering variations in prosthesis height.

Materials and methods: Three cylinder-shaped master files (20 mm long and 11 mm wide) with varying heights (7, 11, and 15 mm) and a titanium-base (Ti-base) abutment space were designed. These designs were used to fabricate a total of 144 specimens with two AM resins indicated for definitive use (Crowntec; AM-CT and Flexcera Smile Ultra+; AM-FS), one high-impact polymer composite (breCAM.HIPC; SM-CR), and one SM strength gradient zirconia (IPS e.max ZirCAD Prime; SM-ZR) (N = 12). Following fabrication, all specimens and Ti-base abutments were prepared according to their respective manufacturers' recommendations prior to adhesive cementation using an autopolymerizing luting composite resin. Each set of specimens was then divided into two subgroups: control and cyclically loaded (n = 6). The specimens in the control groups were subjected to a load-to-fracture test, while the specimens in the cyclically loaded groups underwent 1.2 million loading cycles at 50 N and 1.7 Hz. The surviving specimens from cyclically loaded groups were then tested for load-to-fracture in the same manner. Data were analyzed with generalized linear model analysis and Bonferroni-corrected post hoc tests after logarithmic conversion (α = 0.05).

Results: The fracture strength of tested specimens was affected by the interaction between the material type and aging condition, material type, and prosthesis height (p ≤ 0.020). SM-ZR specimens had the highest and AM-CT specimens had the lowest fracture strength values (p < 0.001), when aged or non-aged. The fracture resistance values of the specimens significantly increased as the prosthesis height increased (p ≤ 0.001). One AM-CT specimen and two AM-FS specimens, all 7 mm in height, failed during cyclic loading.

Conclusions: AM-FS and AM-CT resins may resist masticatory forces in the molar region when the prosthetic height is not smaller than 11 and 15 mm, respectively, despite the use of a molar-size cantilever in the tested thickness.

Purpose: This study aimed to compare the dimensional and positional deviations of additively manufactured removable dies fabricated using two bio-based resins and one conventional dental cast resin, while also evaluating these outcomes over a 4-week period.

Materials and methods: A right mandibular first molar preparation on a typodont was scanned to digitally design removable dies and hollow partial arch casts. Based on a priori power analysis, a total of 30 dies (n = 10) and three hollow casts (n = 1) were fabricated using additive manufacturing (AM) from three different dental cast resins: DentaMODEL (DM), FotoDent bio-based model (CB), and soy-based resin (SB). The dies and their seated positions in casts were digitized 1 day (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4) after fabrication. Dies' dimensional deviations (crown, root, base of the root, and overall) and positional deviations in casts (crown region surface and point-based) at T0 were defined as trueness, while deviations measured over 4 weeks (T0-T4) were defined as stability. The deviations measured at T0 were analyzed either using a generalized linear model (dimensional deviations) or one-way analysis of variance (crown region and point-based deviations). The deviations measured over the 4-week period were analyzed with generalized linear model analysis and Bonferroni-corrected post hoc tests (α = 0.05).

Results: CB dies mostly had the lowest and SB dies mostly had the highest dimensional deviations (p ≤ 0.001). The crown region had the lowest dimensional deviations, while the dimensional deviations measured at T3 were higher than those at T2 and T4 (p ≤ 0.003). SB dies had the highest and CB dies had the lowest positional deviations, while crown region deviations were lower at T0 and T1 than at T4, and point-based deviations were lower at T0 than at T4 (p ≤ 0.049).

Conclusions: CB dies mostly had better dimensional and positional trueness and stability over 4 weeks. The changes in tested outcomes for all dies over time were small.

Purpose: Debonding of zirconia restorations remains a significant clinical challenge due to its glass-free microstructure, which limits micromechanical and chemical adhesion. Zircos-E, a nitric-hydrofluoric acid mixture, has been proposed as a simplified room-temperature alternative to airborne-particle abrasion (APA). This meta-analysis aimed to compare the shear bond strength (SBS) of zirconia surfaces treated with Zircos-E etching versus APA.

Methods: A systematic search of PubMed, Web of Science, and Scopus databases identified in vitro studies published from 2015 to January 2025 comparing Zircos-E etching with APA and reporting SBS values with standard deviations and sample sizes. Eight studies (308 specimens) met the inclusion criteria. Quality assessment was performed using the QUIN tool. A random-effects model was applied to calculate standardized mean differences (SMDs) with 95% confidence intervals (CIs). Subgroup analyses were conducted according to aluminum oxide particle size, and heterogeneity was assessed using the I² statistic.

Results: Overall, Zircos-E etching significantly increased SBS compared with APA (SMD = 1.54; 95% CI: 0.08-3.00; p = 0.04), with substantial heterogeneity (I² = 95%). Subgroup analysis showed no significant difference between 50 and 110 µm Al₂O₃ particle sizes (p = 0.86). Sensitivity analysis excluding the study with the largest effect size reduced the pooled effect (SMD = 1.16; 95% CI: -0.06 to 2.38) and statistical significance (p = 0.06), although the direction of effect remained consistent. In the subgroup analysis by aging protocol, Zircos-E demonstrated a statistically significant improvement in the non-thermocycled subgroup (SMD = 1.72, 95% CI: 0.23-3.21, p = 0.03), while no significant difference was found in the thermocycled subgroup (SMD = 1.38, 95% CI: -1.80 to 4.55, p = 0.30).

This clinical report presents a comprehensive digital workflow for rehabilitating a patient with maxillary terminal dentition using a full-arch, implant-supported fixed dental prosthesis (FP-1). It highlights the integration of a 3D-printed polychromatic flangeless trial denture and a customized anatomic bone reduction template, enabling prosthetically driven implant planning and optimal bone architecture modification. The workflow incorporated fully guided implant surgery using sequential templates and immediate loading with a closed-mouth pickup system. Intraoral scanning protocols were employed for definitive prosthesis fabrication. This approach addressed high esthetic risks while achieving surgical precision, efficient treatment execution, and favorable clinical outcomes.

Purpose: Stress is a significant concern in healthcare professions, impacting both physiological and psychological well-being. In the field of dentistry, stress among practitioners is well-documented; however, there is a notable gap in understanding stress levels specifically within postgraduate prosthodontic training programs. The study hypothesis aimed to assess perceived stress levels among prosthodontic residents and, secondarily, identify associated risk factors, while exploring stress management strategies.

Materials and methods: A cross-sectional, mixed-methods design was employed, utilizing a modified version of the Graduate Dental Environment Stress (GDES) survey along with qualitative open-ended questions. REDCap (Research Electronic Data Capture), a secure, web-based software platform designed to support data capture for research studies, was used for instrument design, data management, and storage. A REDCap Survey link was distributed to prosthodontic program directors across North America, with the intention of distributing it to their residents. Responses were recorded via a Likert scale for the quantitative assessment and through narrative responses for the qualitative assessment. A score of 76 was determined to be the threshold value at or above which the participants were considered stressed. Descriptive summaries were used to characterize the participants. The main study outcome was presented as a percentage of the corresponding 95% confidence interval (CI). The assessment of risk factors of stress among the study population was done by using a logistic regression model, and coping mechanisms were tagged via open coding and presented as themes. SAS statistical software package was used.

Results: A response rate of 13.2% indicated that over a third of postgraduate prosthodontic residents experienced high levels of stress, as defined by a GDES score ≥76. A risk factor for stress was identified as the year of study. Qualitative analysis revealed common themes in stress management strategies, with exercise, socializing, and spending time with family members being the most prevalent.

Conclusion: The findings of high perceived stress among prosthodontic residents included "Lack of time for leisure activities" followed by "Lack of adequate staff in the clinics" and "Neglect of personal life" being the highest reported stressors. Stress management strategies such as "Self-care," "Time management," and "Connecting with others" highlight the importance of proactive strategies to manage stress. By understanding the factors contributing to stress and effective coping mechanisms, stakeholders can better support their residents.