Eighteen-month bracket survival rate: conventional versus self-etch adhesive

Abstract

The aim of this study was to evaluate, over an 18-month period, the clinical performance of a self-etch adhesive [Transbond Plus Self Etching Primer (SEP), 3M Unitek] compared with a conventional adhesive that employs the etch-and-rinse approach (Transbond XT, 3M Unitek). One operator, using the straight-wire technique, bonded 567 metallic brackets to the teeth of 30 patients (age range 12-18 years) in a way that patients acted as self-control. The brackets were bonded following the manufacturers' instructions except for the fact that the self-etch system was brushed for a longer time than recommended (10-15 seconds) since previous investigations have reported that prolonged application times can improve the bonding efficacy of self-etch systems to enamel. The failure modes were visually classified into: adhesive-enamel, adhesive-bracket, and cohesive failure. The survival rates of the brackets were estimated by Kaplan-Meier and log-rank test (P < 0.05). The failure rates of the self-etch and conventional adhesives were 15.6 and 17.6 per cent, respectively. No significant differences in the survival rate were observed between the materials (P > 0.05). Most of the failures were cohesive and at the adhesive-enamel interface. There was no difference in the fracture debonding mode. These findings indicate that Transbond Plus SEP can be safely used for orthodontic brackets since the survival rates are similar to the conventional Transbond XT.

A comparative clinical study of the failure rate of orthodontic brackets bonded with two adhesive systems: conventional and self-etching primer (SEP)

“…Finally, there may be excessive occlusal forces during the initial stage of treatment. 8,11 Some authors have reported a failure rate of up to 82% during this time. 10 Other studies confirmed the efficacy of SEP systems during the first 6 months of treatment when compared with conventional systems.…”

“…13 Several authors conducted shorter studies to compare SEP and conventional systems, from 6 to 12 or 18 months. [8][9][10][11][12][13][14] Our follow-up lasted longer, from 36 to 48 months.…”

“…Some authors found that the failure rate for SEP ranged from 0.6%10 to 15.6% 8 and that the SEP performance was equal to or better than that of conventional systems. Of the 240 brackets bonded with each of the two bonding systems, 11 in the SEP group and 13 in the conventional system group failed, which indicates failure rates of 4.58% and 5.41% (Table 3).…”

“…Moreover, masticatory forces vary according to facial patterns, and diet is associated with cultural factors. 8 original article Dominguez GC, Tortamano A, Lopes LVM, Catharino PCC, Morea C resented failures at the end of the treatment. The fact that most failures occurred in the first 6 months may be assigned to one of three causes.…”

“…Reis et al, 8 who followed up 30 patients for 18 months, found a failure rate of 15.6% for SEP and 17.6% for the conventional system, a difference that was not statistically significant. Pandis et al 9 conducted a study to compare SEP with the Orthosolo and Enlight conventional systems in 62 patients for 12 months and found that the risk of failure in the SEP group was not any greater than in the conventional system group.…”