Evaluation of Chitosan on the Properties of Resins Containing Different Photoinitiators

Objectives: The objective was to evaluate the degree of conversion (DC) and hardness Knoop (HK) of experimental resins containing chitosan (CH) and the photoinitiators bisacylphosphine oxide (BAPO) and camphorquinone (CQ).
Methods: An experimental resin was prepared with a blend of BisGMA and TEGDMA (50/50wt %). To this mixture the photoinitiators systems CQ or an alternative photoinitiator system BAPO were incorporated. The co-initiator used was the amine dimethylamylamine methylmethacrylate. After, four different concentrations of CH (0.0 wt%, 0.5 wt%, 1wt% and 2wt%) were added, producing eight groups for analysis. The photoactivation was made for 20s with LED BluePhase (Ivoclar) in a matrix with 7x2x1 mm (length x width x height). Then, the DC was analyzed in Fourier transform infrared spectroscopy - FTIR (Spectrum100). HK was tested in a microhardness (Shimadzu). The means were evaluated by two-way ANOVA and Tukey’s test (5%).
Results: According to the results of DC (%) and HK (KHN) resins containing BAPO showed higher values than resins containing CQ: BAPO (78.4) > CQ (52.3) and BAPO (22.6) > CQ (1.4), respectively. The addition of CH increased the DC of the resins containing CQ, regardlles of the CH concentration used, while not influenced in HK values. The addition of CH did not influence the results of resins containing BAPO.
Conclusions: The addition of CH does not reduce the properties of the resins analyzed, and may even increase them. BAPO showed to be a more effective photoinitiator that CQ.