Journal of Prosthetic Dentistry最新文献

Removable partial dentures (RPDs) with flange extensions have been recommended for patients with few remaining teeth and extensive tissue loss. Conical crown-retained partial dentures (CCRPDs), a type of RPD, provide favorable clinical performance and patient satisfaction. However, the loss of inner crown retention and fractures at the soldered interface between outer crowns and frameworks remain of concern. Retention control with conventional casting techniques and differential vertical displacement between teeth and implants also present challenges. A digital workflow incorporating design modifications and selective laser melting to fabricate a tooth- and implant-supported CCRPD using a digitally defined fabrication approach is described.

Anophthalmia, resulting from trauma, carcinoma, or congenital causes, necessitates orbital rehabilitation to address both psychological and cosmetic needs. Traditional methods for positioning ocular prostheses have frequently been inaccurate because of errors caused by parallax and differences in facial symmetry. A novel technique is described for replicating the remnant iris using an optometry trial frame to improve the precision and efficiency of custom orbital prosthesis fabrication. The described technique uses a trial framework for precise iris alignment, facilitating measurement transfer from the healthy eye to the wax pattern for the prosthesis. This technique ensures accurate, symmetrical iris positioning by aligning facial midline landmarks and simplifying the clinical workflow. It is cost-effective, less time-consuming, and accessible even for the less experienced, making it advantageous for patients who cannot afford more complex or expensive treatments like surgical or implant-retained fixed prostheses. The technique has been successful in restoring esthetics and self-confidence for individuals with exenterated or enucleated eyes, addressing gaps in traditional techniques.

Accurate alignment of cone beam computed tomography (CBCT) and intraoral digital scans is essential for prosthetically driven implant planning. In patients lacking stable dental structures, existing registration methods such as radiographic templates or adhesive radiopaque markers are often complex, costly, or prone to positional errors. The present technique describes an alternative chairside procedure for fabricating and placing small custom button-shaped radiopaque composite resin fiducial markers directly onto the masticatory mucosa. Sutures ensure fixed spatial positioning throughout both CBCT and intraoral scanning, eliminating the need for dual scan protocols. This approach offers an immediate, straightforward, low-cost, and reproducible option for accurate CBCT-intraoral scan alignment in edentulous and periodontally compromised patients, enhancing the precision and efficiency of digitally guided implant planning.

Statement of problem: Additively manufactured (AM) polymethyl methacrylate (PMMA) crowns exhibit limited color stability, suboptimal surface texture, and insufficient strength. The development of effective reinforcement strategies is essential to overcome these shortcomings.

Purpose: The purpose of this in vitro study was to evaluate the effects of incorporating silica (SiO₂) and titanium dioxide (TiO₂) nanoparticles on the fabrication trueness and the optical, surface, and mechanical properties of AM PMMA crowns.

Material and methods: Mandibular first molar AM PMMA crowns (N=80) were fabricated using 4 materials (n=20 per group): unmodified PMMA (control; FREEPRINT), PMMA with 1 wt% SiO₂ (S), PMMA with 2 wt% TiO₂ (T), and PMMA with a combination of 1 wt% SiO₂ and 2 wt% TiO₂ nanoparticles (ST). Fabrication trueness was evaluated as the root mean square (RMS) surface deviation of the marginal and intaglio surfaces (µm) and their total. Color stability (ΔE₀₀) was assessed using spectrophotometry, and surface roughness (Ra) was measured via noncontact optical profilometry. Wear was assessed by occlusal RMS (µm) after thermomechanical aging; fracture resistance was recorded as peak load to failure (N) on a universal testing machine. Statistical analyses were performed using 1-way ANOVA followed by Bonferroni-adjusted post hoc tests (α=.05).

Results: Fabrication trueness differed among groups (marginal, intaglio, and total RMS; all P<.001), ranking STS>T>ST; qualitative joint evaluation technique (JET) heatmaps showed the same pattern. Fracture load differed (P<.001): T and ST were higher than Control and S, with no significant difference between T and ST.

Conclusions: Incorporating SiO₂ and TiO₂ nanoparticles into PMMA formulations synergistically enhanced the overall performance of AM crowns.

Statement of problem: Polyethylene fibers have been used in dentistry because of their favorable mechanical and esthetic properties. However, there is a need for a metrics-based review to identify publication trends.

Purpose: The purpose of this metrics-based analysis was to assess the publication profile and the social interest in the use of polyethylene fibers in dentistry through a bibliometric and altmetric review.

Material and methods: In October 2025, a search was performed in the Web of Science database. The main characteristics of the retrieved publications were extracted and analyzed, with emphasis on the clinical use and applications of this material. Social attention was evaluated in the Dimensions database using altmetric indicators. Collaboration networks were measured using VOSviewer, and the correlation between citation counts and other variables was determined using the Spearman test. Trend analysis was conducted in a spreadsheet.

Results: The selected studies were published between 1988 and 2025 (n=203). The Journal of Prosthetic Dentistry accounted for the largest number of publications (n=18). Most studies were laboratory-based (n=150), and the most investigated clinical applications were the use of polyethylene fibers for dental restorations (n=101), intracanal posts (n=32), and the reinforcement of fixed prostheses (n=26). Most studies focused on adult populations (n=190). Turkey (n=51) was the leading country in publication output, and Asia was the most represented continent (n=113). Limited social attention (n=14) was observed, mainly from readers on Mendeley and users of X and Facebook. VOSviewer indicated collaboration networks among authors. The trend analysis revealed current interest in the use of this material for dental restorations, intracanal posts, and bone reconstruction.

Conclusions: A consistent number of publications was observed over the 37-year period. The studies were predominantly laboratory-based, mainly evaluating the use of polyethylene fibers in dental restorations for adult populations. The clinical applications of this material have undergone several modifications over the years, serving primarily as reinforcement for restorative materials and dental structures. A shortage of clinical studies was identified.

Statement of problem: The computer-aided design and computer-aided manufacturing (CAD-CAM) of removable partial denture (RPD) frameworks provides a cost-effective alternative to conventional techniques. However, the accuracy of printed patterns can be influenced by printing parameters and storage conditions, leading to distortions that may compromise RPD retention and longevity.

Purpose: The purpose of this in vitro study was to evaluate the effects of printing parameters (layer thickness and support diameter) and storage conditions (storage after 7 days and light exposure) on the trueness of 3-dimensionally (3D) printed RPD frameworks by digital superimposition.

Material and methods: A Kennedy Class II modification 2 maxillary cast was scanned to design an RPD framework. Frameworks were printed in castable resin with a digital light processing printer using 25- or 50-µm layers and 200- or 600-µm supports (n=6 per group). Half of the specimens underwent 7 days of storage in a light box simulating daylight; the others were kept in a lightproof box for the same time. Frameworks were scanned immediately after printing and after storage, and deviations at 12 locations were calculated by superimposing the scans onto the original design. The 2-way ANOVA with the Tukey post hoc test was applied (α=.05).

Results: Trueness varied across framework locations and was significantly influenced by layer thickness and support diameter (P<.05). Frameworks printed with 25-µm layers and 200-µm supports showed the lowest deviation (0.098 ±0.052 mm). Support diameter had a greater effect than layer thickness. Storage by itself increased deviations at rest seats, while the light box conditioning also affected the minor connector, base, and major connector regions (P<.05).

Conclusions: Under the conditions of this study, trueness varied significantly across sites in printed RPD frameworks. Printing parameters of 25-µm layers and 200-µm supports showed the greatest dimensional accuracy. Seven-day storage in a light box introduced additional deviations.