Comparative evaluation to study the effect of implant support on complete fixed dental prosthesis fabricated with peek framework when implants placed in all-on-4 and all-on-6 situation, by strain gauge analysis and finite element analysis - An in vitro study.

Aim: To evaluate and compare the strain development and distribution of maxillary implant-supported complete fixed dental prosthesis (ISCFDP) with computer-aided design-computer-aided manufacturing milled PEEK BIO-HPP superstructure when placed using All-on-4 and All-on-6 situation using a strain gauge and finite element analysis (FEA). Setting and Design: This is an in vitro study to evaluate and compare the stress minimization and strain developed at implant in premolar and in two clinically simulated situation of All-on-4 and All-on -6 ISCFDP. Materials and Methods: The study involved converting a human skull into. stl format to create 3D-printed stereolithography models with a modulus of elasticity closer to bone. Implants were placed in two models (M1 nad M2) in incisor, premolar, and pterygoid regions. A fixed dental prosthesis framework was fabricated on both models, and strain gauge sensors were attached. Statistical Analysis Used: Descriptive and analytical statistics were done. The normality of data was analyzed by the Shapiro-Wilk test. Results: The results obtained were tabulated and it showed strain around the neck of ISCFDP under 100N configuration in strain gauge analysis. Stress was found more in the molar region when compared to the premolar region. This design showed that the largest stress around the neck of ISFDP under 100 N load was found more in the premolar region when compared to the molar region due to the reduction of stresses in the pterygoid region in FEA. Conclusion: In the present study, strain gauge analysis at 100 N for loading at the premolar and molar region shows the reduced strain on tilted implants in All-on-6 situation due to stress dissipation to the terminal pterygoid implant using strain gauge.

Influence of Three Different Denture Cleansers on Surface Roughness and Strength of Heat-polymerizing Resin: An In Vitro Study.

AIM: The purpose of the current study was to evaluate the impact of three different denture cleansers on the strength and surface roughness of heat-polymerizing resin. MATERIALS AND METHODS: A total of 120 resin discs (10 mm in diameter and 2 mm thick) were created using a stainless steel mold for surface roughness testing and flexural strength testing (in accordance with the American Dental Association (ADA) Specification No.12). Samples were divided into one of three groups (40 samples in each group): group I: Clanden, group II: Clinsodent, group III: Fittydent. Samples were immersed in denture-cleansing solutions for 30 minutes every day, and this process was repeated over a period of 15 days. Samples were stored in distilled water at room temperature in between the immersions. A surface analyzer was utilized to compare the surface roughness of each sample before and after immersion treatments. For recording flexural strength, each sample was subjected to three-point bending test by mounting samples on Universal testing machine. Comparing mean values between groups using one-way ANOVA and the Tukeys honest significant difference (HSD) post hoc test. A significance level of 0.05 was used for all statistical calculations Results: After 15 days, the maximum change of mean surface roughness of heat-polymerizing resin was found in Clanden denture cleanser group (2.64 ± 0.12) followed by Clinsodent group (2.26 ± 0.09) and Fittydent group (1.92 ± 0.06). After 15 days, the maximum change of mean flexural strength changes of heat-polymerizing resin was found in Clanden denture cleanser group (94.78 ± 0.14), followed by Fittydent group (98.64 ± 0.03) and Clinsodent group (99.26 ± 0.21). CONCLUSION: Within the limitation, the current study concluded that changes were observed in surface roughness and flexural strength of all heat-polymerizing resin samples after immersion in all three denture cleansers; but least surface roughness and flexural strength changes were observed with the Fittydent cleanser group and Clinsodent group, respectively. CLINICAL SIGNIFICANCE: Cleaning dentures is crucial for maintaining both the prosthesis and oral health; therefore, it is necessary to select a cleanser that is effective without negatively affecting the base resin's qualities over time.