Failure patterns of different bracket systems and their influence on treatment duration: A retrospective cohort study

ABSTRACT Objectives: To compare the failure pattern of four different bracket types and to assess its effect on treatment duration. Materials and Methods: A total of 78 white patients (28 male, 50 female) with a mean age of 12.6 years were included in this retrospective cohort study and treated for a mean period of 30.6 months. The patients were treated in a private practice with stainless steel conventionally ligated brackets, ceramic conventionally ligated brackets, stainless steel self-ligating brackets, or nickel-free self-ligating brackets. The loss of at least one bracket during the course of treatment was analyzed with Cox proportional hazards survival analyses and generalized linear regression. Results: The overall bracket failure rate at the tooth level was 14.1% (217 brackets), with significant differences according to tooth type (between 8.0%–23.4%) and bracket type (between 11.2%–20.0%). After taking confounders into account, patients treated with ceramic brackets lost more brackets (hazard ra...