12 Month Evaluation of a Dual-Cure Provisional Material

Objectives: Most dual-cure (DC) provisional material mechanical properties are reported at 24 hours, but long-term data is limited.
The purpose of this evaluation was to evaluate a DC provisional material flexural strength over 12 months stored in a physiologic solution.
Methods: Flexural strength specimens (n=20) of a DC provisional material (Integrity Multicure, Dentsply Sirona) and the conventional product (Integrity, Dentsply Sirona) were fabricated and tested following ISO#4049 and manufacturer instructions with photopolymerization provided by a multi-spectrum LED VLC unit (Valo, Ultradent). Additional DC specimens (n=20) were fabricated in a self-cure mode with all specimens stored at 37°C in 0.2M phosphate buffered saline. Materials were tested at 1hr, 24hr, 1wk, and 1, 3, 6, & 12mos on a universal testing machine at 0.5 mm/min until fallure. Shapiro-Wilk test confirmed normal distribution and mean data was compared using ANOVA/Tukey's at a 95% confidence level (p=0.05).
Results: Results are posted in the Table. The VLC-activated DC provisional material demonstrated sig greater flexure strength at 1 and 24hr (p<0.0001, p<0.02) but was similar to other materials after 1wk (p>0.05). Each individual material had overall stable flexural strength at 1wk to 3mos with all demonstrating strength increase at 6mos. Flexural strength was similar between the VLC-activated and self-cure material after 24hr with no difference from the conventional product at 1mo and beyond.
Conclusions: Under this study’s conditions, the VLC-activated DC provisional material flexural strength advantage was observed only at 1 & 24 hours.