A retrospective survey of the causes of bracket- and tube-bonding failures

Abstract

Objective: To investigate the causes of bonding failures of orthodontic brackets and tubes and the effect of premedicating for saliva reduction.

Materials and methods: Premedication with atropine sulfate was administered randomly. Failure rate of brackets and tubes placed in a group of 158 consecutive patients was evaluated after a mean period of 67 weeks after bonding.

Results: The failure rate in the group without atropine sulfate premedication was 2.4%. In the group with premedication, the failure rate was 2.7%. The Cox regression analysis of these groups showed that atropine application did not lead to a reduction in bond failures. Statistically significant differences in the hazard ratio were found for the bracket regions and for the dental assistants who prepared for the bonding procedure.

Conclusions: Premedication did not lead to fewer bracket failures. The roles of the dental assistant and patient in preventing failures was relevant. A significantly higher failure rate for orthodontic appliances was found in the posterior regions.

Keywords: Atropine sulfate; Bonding; Bonding failure; Brackets; Tubes.

Figures

Figure 1.

Failure rate (%) per tooth. *Indicates tubes per tooth.

Figure 2.

Kaplan-Meier survival curves for the atropine group and control group. Y-axis indicates the cumulative survival percentage of the brackets. X-axis indicates the follow-up period in weeks.

Figure 3.

Kaplan-Meier survival curves for dental assistants. Y-axis indicates the cumulative survival percentages of the brackets. X-axis indicates follow-up period in weeks.

Figure 4.

Kaplan-Meier survival curves for the maxillary anteriors, maxillary premolars, maxillary molars, mandibular anteriors, mandibular premolars, and mandibular molars. Y-axis indicates cumulative survival percentages of the brackets. X-axis indicates follow-up period in weeks.