Effect of different bonding agents on prevention of enamel demineralization around orthodontic brackets

Abstract

Demineralization around the bracket is an undesired side effect of orthodontic treatment. The aim of this in-vitro study was to evaluate the efficacy of 5 bonding agents to prevent enamel demineralization. Two quantification methods were used. Eighty-five extracted teeth were randomly allocated to 5 groups: (1) Transbond Plus SEP and Transbond XT (both, 3M Unitek, Seefeld, Germany), (2) 37% phosphoric acid, Pro Seal (Reliance Orthodontic Products, Itasca, Ill) and Transbond XT, (3) Clearfil Protect Bond (Kuraray Medical, Okayama, Japan) and Transbond XT, (4) 37% phosphoric acid and Light Bond (Reliance Orthodontic Products), and (5) Ortho Conditioner and Fuji Ortho LC (both, GC, Tokyo, Japan). In-vitro caries was created by pH cycling for 30 days. After demineralization, the teeth were scanned with a commercial cone-beam microtomographic system. Then the teeth were examined by polarized light microscopy. The 2 methods of examination showed significant differences among the 5 groups according to lesion depth and mineral loss (P < 0.01). The resin-modified glass ionomer cement (group 5) had the lowest values for lesion depth and mineral loss. Fuji Ortho LC showed a significantly smaller lesion depth and less mineral loss compared with the other materials. The cone-beam microtomographic system is suitable for evaluation of subsurface lesions and has considerable advantages.