Formulation of Optimized Regression Model for Flexural Strength of Experimental Dental Composite Resins with Nanohydroxyapatite Filler Particles

Abstract

Ab s t r ac t Aims: The study was conducted with the aim of evaluating the mechanical properties of experimental dental composite resins (EDCR) containing nanohydroxyapatite, zirconia, and glass filler particles. Materials and methods: The experimental dental composite resin’s organic matrix was a combination of urethane dimethacrylate (UDMA) and triethylene glycol dimethacrylate (TEGDMA). Camphorquinone (CQ) and dimethylaminoethyl methacrylate (DMAEM) were added as photoinitiators. Ethyl-4-(dimethylamino) benzoate (EDMAB) was added as an accelerator, and butylated hydroxytoluene (BHT) was added as an inhibitor to the organic matrix. A combination of barium aluminum fluoride glass (5–20 nm), zirconia (4–11 nm), and hydroxyapatite (20–80 nm) were added as fillers in varying percentages. The Taguchi method of optimization was used to obtain a composite with optimum flexural strength (FS). A regression model was developed. American Society for Testing and Materials (ASTM) Standard D 790–03 was used to prepare the specimen for testing the FS. Results: Experimental dental composite resin with 23.7% of zirconia, 27.5% of nanohydroxyapatite, and 20% of glass filler particles gave the optimum FS of 164.44 MPa. The confirmatory experimental test of EDCR gave an FS of 168 MPa. The model developed with a regression equation for the FS was FS =2205-339Z+25.6H+353. ZH-194. G+241. Z2-158. H2 The difference between the R-square (99.9) and adjusted R-square values (99.8) is <0.2; this shows that the model is acceptable. Conclusion: The EDCR developed after Taguchi’s method of optimization had FS superior to that of the commercially available composite resins. The regression model obtained for the FS can be used globally to develop a composite resin with zirconia, hydroxyapatite, and glass nanofiller particles. Clinical significance: Restoration of lost tooth structure with a biomimetic material is the need of the hour. Our experimental dental composite incorporates nanohydroxyapatite filler particles, which provide FS similar to that of a natural tooth.