Abstract: Aim This was to compare shear bond strength (SBS) of brackets bonded to deciduous teeth with that of permanent teeth, to evaluate the effect of increasing etching time on the SBS of brackets bonded to deciduous teeth and to evaluate the modes of bond failure after de-bonding. Study design: ex vivo study.
Materials and Methods A total of 120 freshly extracted human maxillary teeth were divided into six groups of 20 teeth each as follows: Group 1, permanent canines with 15-second etching time; Group 2, first premolars with 15-second etching time; Group 3, deciduous canines with 15-second etching time; Group 4, deciduous first molars with 15-second etching time; Group 5, deciduous canines with 30-second etching time; Group 6, deciduous first molars with 30-second etching time. After bonding, all specimens were thermocycled from 5 șC to 55 șC and back to 5 șC 500 times. The modified ARI was used to determine the mode of bond failure. Statistics: Comparison between groups was performed using Univariate General Linear Model (UGLM) and chi-squared tests.
Results SBS for permanent and deciduous teeth etched for 15 seconds averaged 106.60 ± 34.69 N and 96.90 ± 28.51 N, respectively. SBS for deciduous teeth etched for 15 seconds (91.90 ± 32.90 N and 101.80 ± 23.12 N for canines and molars respectively) and 30 seconds (110.40 ± 30.11 N and 94.20 ± 25.74 N for canines and molars, respectively). No significant differences were recorded between the different groups. Bond failure at the enamel-adhesive interface occurred more frequently in the deciduous teeth groups, while failure at bracket-adhesive interface occurred more frequently in the permanent teeth group.
Conclusion SBS of brackets bonded to deciduous teeth was comparable to that of permanent teeth.