Influence of alternative photoinitiators on bond durability, marginal adaptation and chemical-physical-mechanical properties of experimental dental adhesives photoactivated by LED

Abstract

The aim of this study was to evaluate the effect of LED curing units on chemical, mechanical and physical properties, bond strength durability, dental permeability and marginal adaptation of experimental adhesive blends formulated with different photoinitiators. A model adhesive containing a mixture of BisGMA and HEMA, dimethyl amino ethyl methacrilate (co-initiator) will be formulated with different photoinitiators: CQ (Camphorquinone), PPD (1-Phenyl-1,2-Propanedione) and BAPO (Bys-alquil phosphine oxide) and their associations. Specimens will be photoactivated by two LED curing units; one 2° generation (Radii Cal, SDI) and another 3° generation LED (Bluephase C8, Ivoclar Vivadent). The irradiance will be measured by a power meter and the energy dose will be standardized. The physical-mechanical properties of the material Fourier Transformed Infrared Spectroscopy for the degree of conversion (DC) and curing kinetics (CK), dentin permeability (DP), water sorption and solubility (SO ans SL), flexural strength and flexural modulus (FS and FM). For the Bond strength test, the microtensile test will be performed on the planned dentin of 70 human molars, evaluated after 24 h or after one year of water storage. For the marginal adaptation, replicas will be made from the superficial and internal margins of 70 human molars, evaluated by SEM. Then, the data will be submitted to two-way ANOVA and Tukey test, with a pre-set alpha of 0.05. (AU)