IADR Abstract Archives
Mechanical Aspects of Camphorquinone-amine Filler Coating in Dental Resin Composites
Objectives: Camphorquinone (CQ) accompanied with tertiary amine has been used for a long time to excite and activate in dimethacrylate resin composites (RC). Commonly, only a small portion of CQ and amine compounds are added into the resin, followed by the addition of silanized glass fillers. However, some fillers, e.g. Zircon (ZrSiO4) and Zirconia (ZrO2), could be silanized only by some special silanes e.g. 3-acryloxypropyltrimethoxysilane (ACPS) or its bis-1,2-(triethoxysilyl)ethane (BTSE) blended version due to the chemical inertness. Thus, in this study, we aim at studying the mechanical effects of experimental RC activated by CQ-amine coating on Zircon filler.
Methods: For experimental RC, 30.0wt-% ACPS+BTSE-silanized and sieved Zircon (<1.2 microns), coated with 0.7wt-%CQ and 0.7wt-% N,N-dimethyl-p-toluidine (NPT) was prepared in acetone solution. After the overnight-drying, the fillers were added into a resin base (49.0wt-% Urethane dimethacrylate (UEMA) + 19.6wt-% Hydroxypropyl methylacrylate (HPMA)) by hand. For the control RC, same amount of CQ, amine and silanized-Zircon were directly hand-mixed into the resin base without any filler surface pretreatment. After the RCs preparation, they were moulded and light-cured for 40s in cylindrical (Φ6.8×1.3mm, N=24) and rectangular (25.0×2.0×1.0mm, N=36) forms for indentation and three-point bending tests to calculate the Vickers Hardness and Strain Energy, respectively. Before the test, 16 cylindrical and 24 rectangular specimens were separately stored 37oC water for 7 and 14 days, whilst remaining was tested immediately. One-way ANOVA and paired t-tests were used to statistically analyze the data at α=0.05.
Results: One-way ANOVA revealed that both Vickers Hardness (p~2.615×10-35) and Strain Energy (p~7.790×10-9) are significantly different between groups. Paired t-tests showed the CQ-amine coating could significantly improve the Hardness (p<0.05) under the same water storage duration. However, for the Strain Energy, only significant improvement was found initially (p<0.05).
Conclusions: CQ-amine coating could be coated on filler that could improve the resin composites’ mechanical properties.
Methods: For experimental RC, 30.0wt-% ACPS+BTSE-silanized and sieved Zircon (<1.2 microns), coated with 0.7wt-%CQ and 0.7wt-% N,N-dimethyl-p-toluidine (NPT) was prepared in acetone solution. After the overnight-drying, the fillers were added into a resin base (49.0wt-% Urethane dimethacrylate (UEMA) + 19.6wt-% Hydroxypropyl methylacrylate (HPMA)) by hand. For the control RC, same amount of CQ, amine and silanized-Zircon were directly hand-mixed into the resin base without any filler surface pretreatment. After the RCs preparation, they were moulded and light-cured for 40s in cylindrical (Φ6.8×1.3mm, N=24) and rectangular (25.0×2.0×1.0mm, N=36) forms for indentation and three-point bending tests to calculate the Vickers Hardness and Strain Energy, respectively. Before the test, 16 cylindrical and 24 rectangular specimens were separately stored 37oC water for 7 and 14 days, whilst remaining was tested immediately. One-way ANOVA and paired t-tests were used to statistically analyze the data at α=0.05.
Results: One-way ANOVA revealed that both Vickers Hardness (p~2.615×10-35) and Strain Energy (p~7.790×10-9) are significantly different between groups. Paired t-tests showed the CQ-amine coating could significantly improve the Hardness (p<0.05) under the same water storage duration. However, for the Strain Energy, only significant improvement was found initially (p<0.05).
Conclusions: CQ-amine coating could be coated on filler that could improve the resin composites’ mechanical properties.