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

Purpose: This in vitro study aimed to evaluate the accuracy of occlusal relationships in 3D-printed dental casts, comparing two mounting methodologies.

Materials and methods: Maxillary and mandibular dental casts were scanned and digitized for virtual digital design as reference models. A total of 30 pairs of casts were printed using a digital light synthesis (DLS) 3D printer and mounted either based on hand articulation (Group HA) or using computer-aided design (CAD)-generated articulation pins (Group CAP). Accuracy was assessed by using the root mean square (RMS) values and linear measurements against the reference models.

Results: Group HA demonstrated mean RMS values of 147.9, 133.9, and 166.5 for the canine, second premolar, and second molar regions, respectively, with a mean RMS value of 149.4. Group CAP had RMS values of 398.2, 298.9, and 301.4 for the same regions, respectively, averaging at 332.8. Statistically significant differences were observed between the two groups across all sites. Linear measurements also showed notable discrepancies, especially in Group CAP, with significant differences in vertical dimension when compared to the master standard tessellation language (STL) models.

Conclusions: The mounting methodology influences the accuracy of occlusal relationships in 3D-printed dental casts. Group HA demonstrated greater accuracy and consistency in replicating occlusal relationships compared to Group CAP. These findings underscore the importance of selecting an appropriate mounting methodology for precise replication of occlusal relationships in prosthodontic treatments within digital workflows.

Electrical burns to the oral commissure are uncommon injuries that can lead to significant functional and esthetic complications if not promptly and appropriately managed. This case report details the management of a 14-year-old male with post-burn oral commissure scarring resulting from an electrical injury sustained at the age of 6. The treatment included the fabrication and application of a custom commissure splint combined with intralesional corticosteroid injections by a plastic surgeon to improve scar pliability and oral function. The report highlights the integration of dental prostheses and surgical interventions to achieve favorable outcomes.

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.