Tooth-Supported Overdentures Revisited.

The goal of prosthodontics is to provide a functional prosthesis to restore aesthetics, functions, and masticatory efficiencies. Tooth-supported overdentures are one of the treatment options for removable dentures. This article aims to discuss the advantages and disadvantages of tooth-supported overdentures and the principles of using various overdenture attachments, including non-attachment overdentures. The common treatment options in preparing the overdenture abutment are either with or without abutment coping with or without attachment systems, which were discussed and illustrated. A range of tooth-supported overdenture systems were addressed, from low to high financial implications and treatment complexities. The clinician can choose a system that best fits the patient's condition and expectations. This allows clinicians to decide and consider tooth-supported overdentures as a treatment option before full edentulism. A well-executed tooth-supported overdenture ensures the preservation of alveolar bone, optimizes patient satisfaction in denture treatment, and eventually improves the patient's adaptation when transitioning to complete dentures.

Development and validation of a progressive web application to educate partial denture wearers.

Effective delivery of post-insertion instructions is essential for denture care and oral health. This study aimed to develop a progressive web application (PWA) to educate patients' chairside and serve as a reference material. A need analysis was conducted before prototype development. Subsequently, the prototype was subjected to content verification, design appraisal and usability testing. The results of usability testing revealed a user task success rate of 94.4%, with an adjusted Wald 95% confidence interval of 83-100%. User satisfaction assessed using the Single Ease Questionnaire and System Usability Score reported a mean score of 6.13 (95% CI: 5.69-6.55) and 85.9 (95% CI: 82.2-89.6), respectively, indicating good usability. This study highlights the systematic approach of developing an evidence-based educational PWA to meet the usability standards for mobile applications. This PWA is useful in clinical studies to explore mobile technologies' potential in educating denture wearers, especially in the older population.

Effect of training on time efficiency and marginal adaptation of computer-aided design/computer-aided manufacturing crowns among dental students.

INTRODUCTION: The computer-aided design/computer-aided manufacturing (CAD/CAM) technology has revolutionised dentistry at present. An operator's skills can affect the overall clinical duration and marginal accuracy of the prosthesis fabricated through this workflow. The aim of this study was to assess the effect of CAD/CAM hands-on training compared with that of a self-instructional video on the performance of dental students in digital impression and fabrication of a CAD/CAM crown. METHODS: In this cross-sectional study, 30 undergraduate dental students were shown a CEREC demonstration video. Each operator then captured a digital impression using the intra-oral scanner, and a crown was subsequently milled. All participants underwent a training course before repeating the process. Marginal discrepancy for each crown on its abutment tooth was measured before and after training using a stereomicroscope and was evaluated using Wilcoxon signed rank test. The duration taken for the process was recorded before and after training and evaluated using paired t-test. RESULTS: The overall mean ±standard deviation marginal adaptation for the CEREC crowns was 78.15 ± 42.83 µm before training and 52.41 ± 17.12 µm after training. The Wilcoxon signed rank test found significant difference (p < .05) in terms of marginal adaptation of crowns fabricated before and after training. Paired t-tests showed that the time efficiency after training significantly improved compared with that before training. CONCLUSIONS: Training with guided feedback is crucial to improve the time efficiency of making a digital impression and marginal adaptation of fixed prosthesis using the CAD/CAM technology.

Effect of types of resin cements on the bond strength of fiber post under simulated dives.

BACKGROUND: Changes in barometric pressure conditions that occur during flying and diving under hyperbaric oxygen conditions were found to influence the retention of dental restorations. AIM: This experimental laboratory study aimed to evaluate the bond strength of glass fiber posts after being cemented with self-adhesive resin cement (RelyX™ Unicem, 3M ESPE) and self-etch adhesive resin cement (RelyX™ Ultimate, 3M ESPE) under normal atmospheric pressure and hyperbaric pressure cycles that simulate diving conditions. METHODS: A total of 40 extracted, single-rooted mandibular premolars were treated endodontically and randomly divided into two groups according to the cements used for fiber post cementation. Each group was further randomly divided into two equal subgroups that were subjected to normal atmospheric pressure conditions and a simulated hyperbaric condition in a hyperbaric chamber. The pull-out bond strength of fiber posts was tested using a universal testing machine. Data were analyzed using one-way analysis of variance with Tukey post-hoc test (p<0.05). RESULTS: At normal atmospheric pressure the mean value of the pull-out bond strength of RelyX Ultimate cement was significantly higher than that of RelyX Unicem cement. At hyperbaric pressure condition no significant difference was found between the mean values of the pull-out bond strength of RelyX Ultimate and RelyX Unicem cement. CONCLUSION: Hyperbaric pressure cycles demonstrated improved pull-out bond strength of glass fiber posts in RelyX Unicem cement but did not have significant effect on pull-out bond strength in RelyX Ultimate cement. Both resin cements have similar pull-out bond strength of glass fibers post after simulated dives.

Effect of educational progressive web application on patient's oral and denture knowledge and hygiene: A randomised controlled trial.

This study aimed to evaluate the effect of a novel progressive web application (PWA) on the patient's oral and denture knowledge and hygiene. Fifty-two removable partial denture wearers were randomised to receive education using the PWA, or verbal instructions accompanied by demonstration of hygienic procedures. Changes in the participants' knowledge score, plaque index, gingival index and denture plaque was evaluated during a follow-up period of 3 months. The participants' acceptance of PWA was explored through usage logs and a feedback form. Both groups showed significant improvement in knowledge scores, oral and denture hygiene indices (p < 0.001) after education. The PWA group demonstrated significantly lower gingival index score than control (p = 0.008) at the third month review. In conclusion, there is potential of using mobile application in educating elderly patients and the PWA is a viable option for providing post-denture delivery instructions.

The effect of chewing simulation on surface roughness of resin composite when opposed by zirconia ceramic and lithium disilicate ceramic.

OBJECTIVE: To assess the change in surface roughness of nanohybrid resin composite (Tetric EvoCeram) after antagonist wear against monolithic zirconia and lithium disilicate ceramics through a simulated chewing test using a three-dimensional (3D) profilometer. METHODS: A total of 40 Tetric EvoCeram™ resin composite specimens against either a Lava™ Plus zirconia antagonist (n=20) or IPS e.max Press lithium disilicate antagonist (n=20) were prepared for the study. The surface roughness profiles of each resin composite before and after an in-vitro simulated chewing test were analysed using a 3D profilometer and Talymap software. After the simulated chewing, the surface profiles of representative Tetric EvoCeram specimens from each group were analysed using scanning electron microscopy. Independent t-test and paired t-test were used for statistical analysis. RESULTS: For both lithium disilicate and zirconia groups, all surface roughness parameters (Ra, Rt, Sa, Sq,) of Tetric EvoCeram were significantly higher post-chewing compared to pre-chewing (p<0.05); the post-chewing surface roughness parameters of Tetric EvoCeram for the lithium disilicate group were significantly higher (p<0.05) than in the zirconia group. SIGNIFICANCE: This chewing simulation test showed that Tetric EvoCeram composites exhibited a rougher surface when opposing lithium disilicate ceramic compared to opposing zirconia ceramic.