Assessing the effect of chemical surface treatment and joint surface preparations on transverse strength of repaired denture base resin.

The present study was conducted to assess the effect of chemical surface treatment and joint surface preparations on transverse strength of repaired denture base resin. The study included 120 specimens divided into 8 groups of 15 samples each based on the combination of chemical surface treatment with either methyl methacrylate, ethyl acetate, or methylene chloride and chemical surface treatment of rounded joint, 45° bevel, and butt joint. Following surface treatment, dentures were repaired with self-cure resin. After treatment, to assess the transverse strength, they were subjected to a 3‑point bending test. Surfaces that were fractured were assessed under the microscope and were analyzed to AutoCAD for assessing cohesive or adhesive failure type and the area was measured. The study results showed that a statistically significant difference wasseen in most of the comparisons done. Specimens with rounded joints and methylene chloride used for 60 seconds showed the gain of strength of 60%-70& in the present study. The present study concludes that to attain better bond strength in a specimen repaired, the fractured segments of the specimens should be etched with methylene chloride for 60 s and should be given the rounded joints.