Clinical evaluation of complete denture fabricated using two different final impression techniques on masticatory efficiency and oral health-related quality of life.

Aim: To compare the effect of complete denture fabricated using selective pressure impression and functional impression technique on masticatory efficiency and oral health-related quality of life (OHRQoL) in patients with resorbed ridges. Settings and Design: A randomized two arm, parallel group study. Materials and Methods: Forty-eight participants with set inclusion and exclusion criteria were randomly allocated into two groups. Complete denture was fabricated in Group A and Group B using selective pressure and functional impression technique, respectively. The follow-up was done at 3 months. Masticatory efficiency was measured by color-changing chewing gum, and OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI) Hindi Version. Statistical Analysis Used: The Wilcoxon signed-rank test was applied to check the intergroup analysis for the GOHAI scores of both impression techniques. The Mann-Whitney U test was applied to compare intragroup analysis for masticatory efficiency and the GOHAI scores of both the techniques. Results: A total of 45 participants completed the follow-up. The mean age of the total participants was 62.7 ± 3.8. No statistically significant difference (P > 0.05) was observed between the masticatory efficiency and post-GOHAI scores of both the impression techniques. Conclusion: Selective pressure and functional impression techniques may be successfully used to fabricate complete dentures for patients with resorbed ridges.

Evaluation of the effect of dentin surface treatment by air abrasion and Er:YAG laser on the retention of metal crowns luted with glass ionomer cement in teeth with reduced crown height: An in vitro study.

AIM AND OBJECTIVES: The purpose of this study was to investigate the effect of dentin surface treatment with aluminum oxide air abrasion and Er:YAG laser on tensile bond strength of metal crowns. Metal crowns were luted with conventional glass ionomer cement (GIC) in the teeth with reduced crown height, where preparation geometry did not provide optimal retention form. MATERIALS AND METHODS: Forty-eight human premolars were prepared to receive metal crowns and were randomly divided into four groups for tensile bond strength testing. Group A: Untreated dentin luted with self-adhesive composite resin cement as positive control; Group B: Untreated dentin luted with GIC as negative control; Group C: Surface treatment with 50 µm aluminum oxide air abrasion and luted with GIC; Group D: Surface treatment with Er:YAG laser (λ =2.94 mm) with a total energy 84.88 J/cm2 of (60 mJ/pulse, 10 Hz, 60 pulses, and 100 µs pulse width) and luted with GIC. The cemented specimens were thermocycled and later subjected to axial load in a universal testing machine at 0.5 mm/min cross-head speed for tensile testing. Scanning electron microscopic evaluation of dentin surface treatment and cement-dentin interface was also done in representative specimens. RESULTS: One-way analysis of variance showed statistically significant difference among/within the groups (P < 0.001). Tukey's post hoc test presented significant increased tensile bond strength of Er:YAG laser group. Air abrasion group showed no significant increase in tensile bond strength values (P = 0.033). CONCLUSION: Dentin surface treatment with Er:YAG laser significantly improved the tensile bond strength of luting GIC compared to air-abraded and untreated dentin.

Comparative evaluation of the amount of the residual monomer in conventional and deep-frozen heat cure polymethylmethacrylate acrylic resin: An in vitro study.

STATEMENT OF PROBLEM: Heat cure acrylic resin material with reduced monomer content is generally recommended for clinical usage as it leads to improved mechanical, physical, and biocompatibility properties. AIMS AND OBJECTIVE: The purpose of the present study was to evaluate and compare the amount of the residual monomer in the conventional and three different groups of deep-frozen heat cure polymethylmethacrylate (PMMA) acrylic resin. MATERIALS AND METHODS: Totally 40 Specimens of heat cure PMMA acrylic resin (DPI India) (10 conventional heat cure and 30 deep frozen) were made using two disc-shaped stainless steel molds and invested into type II dental stone using compression molding technique. Each group contained 10 specimens (n = 10). Group 1: Control group of conventional polished PMMA specimen stored in water for 24 h at +37°C (10 specimens), Group 2: Deep frozen unpolished PMMA (10 specimens), Group 3: Deep frozen polished PMMA (10 specimens), and Group 4: Deep frozen polished PMMA specimen stored in water for 24 h at +37°C (10 specimens). Amount of the residual monomer content in all the specimens was measured using high-performance liquid chromatography. Data were analyzed using One-Way Analysis of Variance and multiple comparison Tukey's post hoc test (α = 0.05). RESULTS: Least residual monomer content was found in Group 4 (0.12 wt%) followed by Group 3 (0.19 wt%), Group 2 (0.23 wt%), and Group 1 (0.26 wt%). Statistically significant difference (P < 0.05) was found in residual monomer content for all the four groups tested. Post hoc test for intergroup comparison also showed a significant difference between groups. CONCLUSION: The amount of the residual monomer was found to be least in deep-frozen polished PMMA specimen stored in water for 24 h at +37°C (Group 4). Thus, it can be concluded that deep freezing, polishing, and storing in water can reduce the residual monomer content.

A Three Month Comparative Evaluation of the Effect of Different Surface Treatment Agents on the Surface Integrity and Softness of Acrylic based Soft Liner: An In vivo Study.

INTRODUCTION: Acrylic based soft liners are cost effective, yet are inferior in durability as compared to silicone based liners. Hence, this study was conducted to evaluate if the softness and surface integrity of acrylic based soft liner can be maintained by using different surface treatment agents. AIM: To comparatively evaluate the effects of Varnish, Monopoly and Kregard surface treatment agents on the surface integrity and softness of acrylic based soft liner at baseline, at one month and after three months. MATERIALS AND METHODS: A total of 37 participants who required conventional maxillary dentures were selected according to the determined inclusion and exclusion criteria of the study. In the maxillary denture on the denture bearing surface, eight palatal recesses (5 mm x 3 mm) were made and filled with acrylic based soft liner (Permasoft). The soft liners in these recesses were given surface treatment and divided as control (uncoated), Varnish, Monopoly and Kregard groups. The hardness and surface integrity were evaluated with Shore A Durometer and Scanning Electron Microscope (SEM) respectively at baseline, one month and three months interval. Surface integrity between groups was compared using Kruskal-Wallis test. Intergroup comparison for hardness was done using ANOVA and Tukey's HSD post-hoc tests. RESULTS: Amongst all the groups tested, surface integrity was maintained in the Kregard group, as compared to control, Varnish and Monopoly groups for all three time intervals (p< 0.001). Kregard treated samples also demonstrated significantly higher softness at all the time intervals (p<0.001). CONCLUSION: Surface treatment with Kregard demonstrated better surface integrity and softness at all the time intervals.

Overdenture locator attachments for atrophic mandible.

Implant-supported overdentures provide a good opportunity for dentists to improve oral health and quality-of-life of patients. Atrophic mandible poses a significant challenge to successful oral rehabilitation with dental implants. In this article, the fabrication of lower overdenture by two narrow platform implants is described with dual retentive, resilient, self-locating locator attachment system. The locator attachment system has the lowest profile in comparison with the ball and bar attachments and is versatile up to 40° of divergence between two implants. By using locators as attachments, we can meet functional, economic and social expectation of patients with ease and satisfaction.

Comparison of bond strength of auto polymerizing, heat cure soft denture liners with denture base resin - An In Vitro study.

Optimum bond strength between denture soft liner and denture base resin is very important for the success of any denture prosthesis. The tensile bond strength of two commercially available silicone-based heat cured (Molloplast B) and auto polymerizing (Mollosil) was compared with denture base material (trevalon). Molloplast B-trevalon bond in both un-polymerized (dough stage) and already polymerized forms were also compared. Lloyds Universal testing machine was used to test 60 samples. Molloplast B bond strength was greater than Mollosil soft denture liner; it was even greater when packed against trevalon in an un-polymerized form than an already polymerized trevalon using primo adhesive. Both the soft lining materials used are acceptable for clinical usage.