Aim: To Compare and Evaluate the Flexural Strength and Surface Roughness of Lucitone-FRS, Valplast (Flexible Denture Base Materials) and Trevalon (Heat Cure Denture Base Material).Materials and Methods: Three stainless steel master dies of dimension 65 x 20 x 3 mm were fabricated and were invested in standard metal denture flask. A total of 60 specimens were fabricated with 20 specimens of each type of denture base material. Fabrication of a Heat Cure Acrylic Denture Base Resin Specimen was Done Followed by Fabrication of Flexible Denture Base Resins Specimen. In the same manner, samples were fabricated for Lucitone-FRS, and Valplast. These specimens were further divided into two subsets; containing 10 specimens each from each group. In one subset, Flexural Strength was Measured while in the other subset, Surface Roughness was measured. The Surface Roughness values were measured using a surface testing machine Mitutoyo-SJ-Series 201 (Japan). The flexural strength of specimens was measured using a 3-point bending test device on universal testing machine. All the results were compiled and Analyzed by SPSS software.Results: Flexural strength was found maximum in the VALPLAST and minimum in LUCITONE. Surface Roughness Test was done on total 10 samples of each material, i.e. Lucitone-FRS, Valplast and Trevalon. Results for Surface Roughness Test are Valplast has maximum Surface-Roughness followed by Trevalon and minimum in Lucitone-FRS on both polished and unpolished surface. Conclusion:Trevalon can be ideal in cross-arch stabilization cases and Valplast and Lucitone FRS can be successfully used in cases of small arch complete dentures and removable partial dentures. Clinical Significance:The selection of the right denture base material is imperative as it largely affects the overall clinical outcomes and comforts. Results of the present study would aid the dentist in the selection of ideal denture base materials for specific cases like those requiring Cross Arch Stabilization, Small Arch Complete Dentures, and Removable Partial D entures.

Aim: The aim of the study is to investigate the effect of joint surface preparations and chemical surface treatment given to prepared surface on the transverse strength of repaired denture base resin. Methodology: Two hundred and twenty specimens (DPI India) were randomly allocated into eight groups (n = 10), according to the combination of joint surface preparation (Butt joint, 45° bevel, and rounded joint) and chemical surface treatment (methylene chloride, ethyl acetate, and methyl methacrylate) for 30 and 60 s each. Specimens, after surface treatment, were repaired with self-cured resin (DPI India) and then subjected to 3-point bending test to measure transverse strength. Fractured surfaces were viewed under stereomicroscope and subjected to AutoCAD analysis to determine type of failure (adhesive or cohesive) and measure their area. Measurement data were analyzed by one-way analysis of variance, paired t-test, Dunnett's D test, and multiple comparison Bonferroni t-test, with a 5% significance level. Results: Most of the comparisons between the test specimens were statistically significant. Specimens (methylene chloride for 60 s and rounded joint) show 60%–70% gain of strength. Conclusions: For providing better bond strength to a repaired specimen, the segment of fractured specimens to be provided “Rounded joint” preparation with etching by methylene chloride for 60 s.