Bond Strength of Methacrylate-based Blends Containing Elastomeric Monomers and Alternative Initiators after Thermomechanical Cycling

Author(s)

Ely, Caroline ^[1] ; Ottoboni, Thiago Dias ^[1] ; Kumagai, Rose Yakushijin ^[1] ; de Souza, Natalia Alves ^[1] ; Ramos, Tatiana da Silva ^[2] ; Galvao Arrais, Cesar Augusto ^[3] ; Piva, Evandro ^[2] ; Reis, Andre Figueiredo ^[4]

Affiliation

^[1] Univ Guarulhos, Dent Res & Grad Studies Div, Dept Restorat Dent, Guarulhos, SP - Brazil

^[2] Univ Fed Pelotas, Biomat Dev & Control Ctr, Pelotas, RS - Brazil

^[3] State Univ Ponta Grosse, Dept Dent, Ponta Grossa, PR - Brazil

^[4] Univ Florida, Dept Restorat Dent Sci, Div Operat Dent, Coll Dent, Gainseville, FL - USA

• Document type: Journal article
• Source: Journal of Adhesive Dentistry; v. 21, n. 3, p. 281-286, MAY-JUN 2019.
• Web of Science Citations: 0

Abstract

Purpose: To evaluate the bond strength to dentin produced by experimental adhesives formulated with an elasto-meric methacrylate monomer (EMM) and an alternative initiator system based on a Thioxanthone derivative (QTX). Materials and Methods: A self-etching primer was used. For the bonding resin, a model adhesive (G1) was formulated containing bis-GMA/TEG-DMA/HEMA (co-monomeric blend) + CQ/EDAB (initiator system). The other groups were formulated by adding to this formulation: EMM only (G2), QTX (G3), or EMM and QTX (G4). Clearfil SE Bond was used as the commercial control group. Fifty bovine teeth (n = 5) were restored with each one of the five adhesives. After restorative procedures, half of the specimens were stored in distilled water at 37 degrees C for 24 h. The other half was fixed on a metal stub and subjected to 200,000 mechanical (50 N loading at 2 Hz frequency) and 1000 thermal cycles (5 degrees C and 55 degrees C). Afterwards, specimens were serially sectioned into beams and tested in tension until fracture. Bond strengths were statistically analyzed by two-way ANOVA and Tukey's test (alpha = 5%). Results: After 24 h, significantly higher mu TBS was observed for the formulation containing EMM and QTX (G4) when compared to Clearfil SE Bond (p < 0.05). No significant differences in mu TBS were detected among the experimental groups after 24 h (p>0.05). After thermomechanical cycling, no significant differences were observed among groups. Conclusion: The addition of EMM and QTX can be considered as possible alternative in dental adhesive formulations. (AU)

• FAPESP's process: 14/23401-3 - Development of monomeric blends containing methacrylates with elastomeric behavior in association with photoinitiated alternative systems for application in dental materials
• Grantee: André Figueiredo Reis
• Support Opportunities: Regular Research Grants