Comparative Evaluation of Water Soluble Photoinitiators on the Mechanical and Physical Properties of Experimental Composite: An In Vitro Study.

Background: Composite resin restoration is technique sensitive, where there is poor control over moisture leading to incomplete polymerization of the monomers. Hence, it is imperative to study a material which improves the mechanical and physical properties of the resin composite in the moist, oral environment, which is less affected by the saliva.

Aim: The aim of this study was to synthesize composite resin by combining water soluble photoinitiator such as 2,4,6-trimethylbenzoyl phosphine oxide (TPO) (type II) and camphorquinone (CQ) photoinitiator (type I) and to investigate mechanical and physical properties with and without salivary contamination when compared to traditional composite with CQ alone.

Methodology: Experimental composite resin was synthesized by combining water soluble photoinitiator such as 2,4,6-trimethylbenzoyl phosphine oxide (TPO) with CQ photoinitiator. Samples were prepared based on ISO 4049 guidelines and divided into experimental composite with salivary contamination (n = 50), and without salivary contamination (n = 50) and traditional composite (SOLARE X-GC company) with salivary contamination (n = 50) and without salivary contamination (n = 50). Properties such as compressive strength, tensile strength, shear bond strength, degree of conversion, and depth of cure were evaluated.

Results: Experimental composite with salivary contamination had shown statistically significant difference in mechanical and physical properties when compared to traditional composite.

Conclusion: This study concluded that combining water soluble photoinitiator such as TPO (type II) with CQ (type I) provides a synergistic effect by increasing the mechanical properties under salivary conditions.