Bonding orthodontics brackets to enamel using experimental composites with an iodonium salt

• Published in: European journal of orthodontics Vol. 36; no. 3; pp. 297 - 302
• Main Authors: Costa, Ana R, Vedovello-Filho, Mário, Correr, Américo B, Vedovello, Silvia A S, Puppin-Rontani, Regina M, Ogliari, Fabricio A, Moraes, Rafael R, Correr-Sobrinho, Lourenço
• Format: Journal Article
• Language: English
• Published: England 01-06-2014
• Subjects: Adhesives; Animals; Biphenyl Compounds - chemistry; Cattle; Dental Bonding - methods; Dental Enamel; Dental Stress Analysis - methods; Dentistry; Light-Curing of Dental Adhesives - methods; Onium Compounds - chemistry; Orthodontic Brackets; Orthodontics; Resin Cements - chemistry; Shear Strength; Surface Properties
• ISSN: 0141-5387; 1460-2210
• DOI: 10.1093/ejo/cjt051

This study investigated whether the addition of diphenyliodonium chloride (DPC) to experimental resin bonding agents would allow fixation of brackets to enamel using shorter light exposure times.
Photoactivated dimethacrylate-based composites were prepared containing DPC molar concentrations of 0 (control), 0.5 (R05), or 1 per cent (R1). Metallic brackets were bonded to bovine incisors and the bond strengths were evaluated using a shear test. In total, 18 groups were tested (n = 15 per group) defined by three bonding materials (control, R05, or R1), three light-activation time (8, 20, or 40 seconds), and two storage periods (10 minutes or 24 hours). The adhesive remnant index (ARI) was scored under magnification. Data were statistically analysed at a 5 per cent significance level.
At 10 minutes, the control composite showed lower bond strengths than the DPC-modified bonding agents for all light-activation times. Differences in bond strengths between both DPC-modified agents were not significant. Lower bond strengths at 10 minutes were generally observed for groups light activated for 8 seconds compared with groups light activated for 20 and 40 seconds. At 24 hours, no significant differences were observed among the light-activation times. The bond strengths at 24 hours were higher than the bond strengths at 10 minutes for all groups. A predominance of ARI scores 2 and 3 was generally observed.
The use of a ternary photoactivation system containing an iodonium salt in bonding composites may allow bonding brackets to enamel using reduced light exposure times.