Iodonium salt incorporation in dental adhesives and its relation with degree of conversion, ultimate tensile strength, cell viability, and oxidative stress

• Published in: Clinical oral investigations Vol. 23; no. 3; pp. 1143 - 1151
• Main Authors: Ferrúa, Camila Perelló, Leal, Fernanda Barbosa, de Oliveira Gazal, Marta, Ghisleni, Gabriele Cordenonzi, de Carvalho, Rodrigo Varella, Demarco, Flávio Fernando, Ogliari, Fabrício Aulo, Nedel, Fernanda
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2019; Springer Nature B.V
• Subjects: Adhesives; Cell adhesion; Cytotoxicity; Dentistry; Fourier transforms; Infrared spectroscopy; Medicine; Original Article; Oxidation; Oxidative stress; Polymerization; Superoxide dismutase; Tensile strength; Thiobarbituric acid; Ultimate tensile strength; Polymerization; Degree of conversion; Oxidative stress; Cell viability; Diphenyleneiodonium
• ISSN: 1432-6981; 1436-3771
• DOI: 10.1007/s00784-018-2527-6

Objective The aim of this study was to evaluate the degree of conversion, ultimate tensile strength, cell viability, and oxidative stress of two different ternary initiation systems, using two photoinitiation polymerization times. Methods The groups investigated were camphorquinone (CQ); CQ and diphenyleneiodonium hexafluorophosphate (DPI); CQ and ethyl 4-dimethylamine benzoate (EDAB); and CQ, EDAB, and DPI, with EDAB in high and low concentration. To assess the degree of conversion (DC) and the ultimate tensile strength (UTS), a real-time Fourier transform infrared spectroscopy and a universal test machine Emic DL-500 were used, respectively. Cell viability and oxidative stress were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), superoxide dismutase (SOD), total sulfhydryl (SH) content, and thiobarbituric acid reactive species (TBARS) formation assays. Results Slight lower cell viability was shown when DPI was associated with high concentrations of EDAB; this reduction seemed to be attenuated when lower concentrations of EDAB were used. When EDAB and DPI were associated, no oxidative damage was shown. The degree of conversion was increased in the ternary systems (CQ + EDAB lower concentration + DPI) group, which did not affect the UTS, cytotoxicity, and oxidative stress parameters. The polymerization time did not affect cell viability, total SH, and TBARS; however, a slight increase was shown in SOD levels. Clinical relevance Our study emphasizes the relevance of incorporating the third element—iodonium salt—in a binary adhesive systems composed exclusively of CQ and EDAB.