Comparative Evaluation of Flexural Strength and Surface Roughness of Three Different Commercially Available Provisional Restorative Materials: An In-vitro Study

Introduction: Provisional restorative materials require good mechanical properties for long term restorations. Provisional restorative materials are continuously being updated and improved upon for these mechanical, biological and esthetic properties.

Aim: To determine and compare the surface roughness and the strength of three different commercially available provisional restorative materials at different periods.

Materials and Methods: This in-vitro study involved 120 samples of a stainless steel mould fabricated and equally divided. The study was carried out for one year in the Department of Prosthodontics and Crown & Bridge, School of Dental Sciences, Sharda University between June 2020 to June 2021. Materials compared were Dental Products of India (DPI) heat cure acrylic, Protemp 4 and Revotek LC. Each group was further categorised into four groups to measure the flexural strength (after 24 hours, storage in artificial saliva for seven days and 30 days) and surface roughness. A Universal Testing Machine determined the flexural strength and Perthometer for surface roughness. Statistical analysis was done using a one-way Analysis of Variance (ANOVA) test followed by a post-hoc test.

Results: In the three types of materials studied, flexural strength after 24 hours, 7 days, and 30 days was statistically significantly higher (p-value=0.001) in DPI than Protemp 4 and Revotek LC whereas, DPI exhibited a decrease in surface roughness when compared to Protemp 4 and Revotek LC (p-value=0.002).

Conclusion: Within the limitations of the study it was found that DPI demonstrated a higher flexural strength at 24 hours than Protemp 4 and Revotek LC. After storage in saliva for 7 days and 30 days, there was a decrease in the flexural strength of three commercially available provisional materials. The mean surface roughness of Revotek LC was more than DPI and Protemp 4.