A comparative clinical trial of a compomer and a resin adhesive for orthodontic bonding

The study aimed to compare the survival time and cariostatic potential of a compomer to that of a resin adhesive when used to bond stainless steel ort hodontic brackets to labial segment teeth only. The effect of the patients' sex, age at the start of treatment and presenting malocclusion on bracket survival time was assessed also. Forty-five consecutive patients who attend ed for tired appliance therapy were randomly selected. Four hundred twenty- six brackets were bonded (213 with compomer and 213 with resin adhesive) wi th a split mouth design; the right or left side allocation of compomer in e ither arch was alternated. Color transparencies of the maxillary incisors, mandibular incisors, or both, and transparencies of the canines, were taken before treatment. At the debond stage, the transparencies were projected ( 20X) and assessed by an experienced examiner, who used a caries index. The survival time distributions for brackets bonded with each bonding agent wer e not significantly different (P = .74, paired Prentice-Wilcoxon test; P = .75, Akritas test), with bracket failure rates of 17% and 20% recorded for compomer and resin adhesive, respectively. Neither the patients' sex (P = . 85) nor malocclusion (P = .26) appear to affect significantly bracket survi val, but patient age was identified as a useful prognostic indicator of bra cket survival (P < .001). On average, there was more decalcification relate d to brackets bonded with resin adhesive than with compomer (P = .0075). Su rvival time distributions of brackets bonded with compomer or resin adhesiv e appear comparable, but decalcification was reduced significantly by bondi ng with compomer.