RESUMO
OBJECTIVE: The objective of this split-mouth clinical trial was to compare bonding failure rates of metal brackets bonded with two different light-emitting diode (LED) light-curing lamps with different high-intensity power outputs. MATERIALS AND METHODS: Forty patients were included for a total of 800 brackets that were randomly bonded (left and right sides in a 1:1 ratio) in maxillary and mandibular arches using two different LED devices. An LED of 3200 mW/cm2 and an LED of 5000 mW/cm2 were used in this split-mouth clinical trial. Bonding failures during the initial 6 months of orthodontic treatment were recorded as maxillary versus mandibular, anterior teeth versus posterior teeth, and left side versus right side. RESULTS: Five dropouts were recorded for discontinuing orthodontic treatment and 700 brackets were analysed in total. The bonding failure rates for 3200 and 5000 mW/cm2 LEDs were 6.0 and 7.4 per cent, respectively (P = 0.450), which were not statistically significantly different. There were no significant differences in bracket survival rates between the LEDs used (P = 0.866). The posterior teeth presented a higher index of bond failures (odds ratio, 3.14; 95% confidence interval, 1.68-5.87; P < 0.001). LIMITATIONS: Direct comparison was only done between two high-intensity LED lights rather than against conventionally used halogen lights. CONCLUSION: Similar bonding failures were recorded using both LED devices (3200 and 5000 mW/cm2). Significantly more bonding failures occurred in premolar teeth than in anterior teeth.