Evaluation of Flexural Strength and Degree of Conversion of Temporary Crown Materials at Different Ageing Periods in Artificial saliva

Abstract

Objective: Evaluate the effects of different storage periods on flexural strength (FS) and degree of conversion (DC) of four bis-acryl resin provisional restorative materials. Materials and method: A total of 60 specimens were prepared from four temporary crown materials available commercially, and assigned into the four tested groups (n = 15): Group A (Prevision Temp), Group B (B&E CROWN), Group C (Primma art), and Group D (Charm temp). The specimens were stored in artificial saliva, and FS was tested after 24 h, 7 d, and 14 d. A standard three-point bending test was conducted using a universal testing machine. Additionally,  the DC was determined using a Fourier-transform infrared spectroscopy (FTIR) device. The data were statistically analyzed by two-way ANOVA, Tukey HSD multiple comparison, and Bonferroni test at a significance level of 5 %. For each  group, Paired Samples Test was applied to cmpare the DC of immediate and 24 h. Results: The highest FS value was found for Prevision Temp material, while the Charm Temp material showed the lowest FS, with no statisttiCal significant difference between the mean values of the groups at 24 h, while there were significant differences at 7 and 14 d of storage. Prevision Temp had the highest mean DC value, which was significantly different from other materials. Conclusion: Prevision Temp showed higher FS and DC than the other tested materials. The FS of provisional restorative materials is not significantly influenced by storage at first 24 h.