The effect of adding silica nano particles on the diametral tensile strength properties of type4 dental Stone

Abstract

Introduction:Dental stone (gypsum) is a mineral product in the form of hemihydrate (calcium sulfate hemihydrate, CaSO4•1/2H2O), which is used in the process of making all kinds of dental prosthesis. Dental stones must have enough strength and resistance so that they do not break, wear and do not change shape and dimensions in the laboratory stages and during wax-up and pouring. Various methods have been studied to increase the properties of dental stone, one of which is adding nanoparticles to dental stone. In this study, the effect of adding different percentages of silica nanoparticles (0.5, 1, 2, and 5) on the diametral tensile strength (DTS) of dental stone type 4 was investigated, which is a continuation of previous researches and studies. If the desired results are achieved, these particles can be used to improve the properties of dental acetone.

Materials and methods: In this study, silica nanoparticles (silicon dioxide) with percentages of 0.5, 1, 2 and 5 were added to dental stone type 4. 100 specimens were prepared in the form of disks with dimensions of 3 mm height and 6 mm diameter in 4 groups containing the various percentages of nanoparticles and one control group that was dental stone without nanoparticles. Diametral tensile strength was measured using a Universal Testing Machine. Then Diametral Tensile Strength was calculated using an equation in megapascals (MPa). The obtained quantitive data were reported as mean and standard deviation. In order to compare the diametral tensile strength in different groups, the statistical test of ONE WAY ANOVA or its non-parametric equivalent Kruskal Wallis and SPSS.26 software was used. The normality of the data eascheked using the Kolmogorov Smironov test. A significance level of 0.05 was considered.

Results: According to the limitations of this study and the results of statistical tests, it seems that the addition of silica nanoparticles to dental stone type 4 plaster increases the diametral tensile strength of this material, but this increase is not statistically significant (P value < 0.05), also between the groups The highest amount of diametral tensile strength was related to the 5% group and the lowest amount was related to the 2% group, although this difference is not significant (P value < 0.05).

Conclusion: Considering the positive effect of adding nanoparticles on the improvement of surface hardness and dimensional accuracy, also considering the lack of negative effect of adding nanoparticles on the diametral tensile strength, it can be concluded that adding nanoparticles to dental stone type 4 plaster can be used in dentistry.