Evaluation of bond strength to dentin of experimental adhesives containing diphenyl iodonium hexafluorophosphate (DPHIF) and 10-metacriloiloxidecil dihidrogeniofosfato (10-MDP)

• Grant number: 18/12812-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2018
• End date: October 31, 2019
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Adilson Yoshio Furuse
• Grantee: Karla Druzian Oliveira
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The incorporation of the diphenyl iodonium hexafluorophosphate (DPHIF) in adhesive systems that have camphorquinone/amine as photoinitiator/catalyst has been related to improvements in the mechanical properties of dental adhesives, mainly regarding the increase of polymerization rate, but there is a few information about the influence of the addition of this salt to the adhesives to the bond strength of restorative materials to the dentin substrate. The aim of this work is to characterize experimental adhesives containing CQ/amine or CQ/amine/DPIHP as photoinitiators and different concentrations of 10-MDP (0%, 3% and 12%) and photocured with two types of a standard LED device with an irradiance of 1000 mW/ cm2 (Dabi Atlante, Ribeirão Preto, SP, Brazil) and a multi-wavelength LED with irradiance of 1100 mW/cm2 (VALO Cordless, Ultradent Products Inc., South Jordan, UT, USA). For the analysis of bond strength, one hundred and twenty healthy human third molars will be sectioned for dentin exposure and submitted to adhesive procedures with different experimental adhesives and two increments (2 mm each) of composite resin (Filtek Z350, 3M ESPE, St. Paul, MN, USA) will be inserted into the dentin and photocured for 20 seconds each. Subsequently, the dentin-adhesive-resin assembly will be taken to an Isomet Low Speed Saw cutting machine (Buelher Ltd. Lake Bluff, IL, USA), to obtain 0.8 mm thick sticks and, in sequence, to the Instron machine (Model 3342, Instron Corp., Canton, MA, USA) for microtensile bond strength test perpendicular to the adhesive interface at a rate of 0.5 mm/min until specimen rupture. After the rupture of the specimens, the specimens will be evaluated for failure mode in adhesive, cohesive, or mixed failure. The three criteria Variance Analysis test and Tukey multiple comparisons analysis will be applied, with a significance level of 0.05.