ASSESSMENT OF POLYMERIZATION SHRINKAGE IN RESIN BASED COMPOSITE IMPREGNATED WITH VARIOUS CONCENTRATION OF CELLULOSE NANOCRYSTALS

Abstract

The aim of this research was to determine polymerization shrinkage of resin based composite impregnated with various concentrations of cellulose nanocrystals (CNC). This was an experimental laboratory based study conducted in Peshawar Dental College and Material Research Lab, University of Peshawar from 2020 to 2021. In this study, an experimental composite (EC1) was made and then modified with 0, 2, 4, 6 & 8 wt% CNC. EC1 was taken as the control group, and the interventional groups were designated as EC2, EC3, EC4 & EC5 with 2, 4, 6 & 8 wt% CNC respectively. These were also compared with a commercially available RBC, Coltene (A). For measuring polymerization shrinkage, Archimedes principal was employed. Data was analyzed using One-way ANOVA and Dunnett’s test. P value less than 0.05 was considered as significant.

EC5 exhibited lowest shrinkage (1.4%) followed by EC4 (1.7%), EC3 (2.3%), EC2 (2.7%) and EC1 (3%) respectively. EC2, EC3, EC4, EC5, showed significantly lower polymerization shrinkage when compared to EC1 (p<0.05). Similarly, polymerization shrinkage for EC4 and EC5 was significantly lower as compared to the Coltene (A) (p<0.05). Based on the results it was concluded that modification of the experimental RBC with CNC significantly decreased its polymerisation shrinkage.