Effect of Curing Time on Physico-mechanical Properties on Dental Composite

Mayuri Gupta; A. K. Tyagi; Manoj Raula

doi:10.37591/jopc.v10i3.6607

Abstract

This study aim to investigate the influence of curing time on physical and mechanical properties of a dental composite cured by using LED light with intensity of 1500 mW/cm2 in the range of 440-480 nm. We prepared the glass ionomer powder by fusion of various inorganic components at high temperature and studied the influence of silica/alumina ratio keeping other inorganic salts such as Calcium fluoride (CaF2), Sodium Fluoride (NaF), Calcium carbonate (CaCO3), Cryolite (Na3AlF6) and Phosphorous oxide (P2O5) constant. Ratio of silica/alumina vary from 1:1, 1.5:1, 2:1 and 2:3 and study the mechanical properties i.e. compressive and flexural strength and results shows that 1.5:1 silica/alumina ratio gives highest compressive strength 130 MPa and flexural strength as 27 MPa respectively. Developed glass ionomer powder characterized by FTIR before and after fusion along with XRD and SEM-EDX which reveal that all inorganic components are completely fused and that all particles have irregular shapes with less than 20 micron size. Resultant glass ionomer powder mix with commercial polymer in recommended ratio and cured by LED with three different curing time 10 sec, 20 sec, 30 sec. and studied the physical and mechanical properties i.e. thermal stability, compressive strength and flexural strength. Thermal analysis indicate that composite cured by 10 sec have lowest thermal stability due to some uncured resin which also directly effect on compressive and flexural strength of composite. On the other hand composite cured by 20 sec shows highest thermal stability, Flexural and compressive strength while composite cured by 30 sec have no significant changes on their physico-mechanical properties.