COMPARISON OF THE SURFACE ROUGHNESS OF REFRACTORYCAST INVESTMENT MATERIAL BEFORE AND AFTER TREATMENTWITH WAX, HARDENING AGENTS- AN IN-VITRO STUDY

Abstract

Background: Achieving a smooth surface on refractory casts is essential for the accuracy and longevity of dental prostheses. Phosphate-bonded investment materials, although thermally stable, often exhibit surface roughness during wax pattern fabrication and processing. Aim: To evaluate and compare the surface roughness of refractory cast investment material before and after treatment with hardening agents and subsequent heat treatment. Materials and Methods: Twenty rectangular specimens were fabricated using commercially available phosphatebonded investment material. Initial surface roughness was measured using a contact profilometer. Specimens were randomly divided into two groups (n=10): Group I treated with model hardener and Group II treated with beeswax. Surface roughness was re-evaluated after treatment. All specimens were then subjected to heat treatment at 875°C for 60 minutes, followed by gradual cooling, and final measurements were recorded. Statistical analysis was performed using Student’s t-test. Results: A statistically significant reduction in surface roughness was observed in both groups after hardening and heat treatment (p < 0.05).