Comparisons of debonding forces between different tooth types.
S.E Bishara, M.E. Olsen, A. Sulieman
Hellenic Orthodontic Review 1999;2:9-16.
Following the introduction of the direct bonding of orthodontic brackets to enamel, numerous studies were designed to investigate the bonding characteristics of various adhesive systems. In these studies, different tooth types were used for testing including, incisors, premolars and molars. A confounding factor was related to the effect of using different tooth types on bond strength. The purpose of the present study was to compare the shear bond strength of orthodontic brackets to the enamel surface of various tooth types, while eliminating the influence of other extraneous variables such as differences in the adhesive system used and variation in the bracket base design.
Sixty freshly extracted human teeth including 20 molars, 20 premolars, and 20 incisors were similarly prepared for bonding. The same orthodontic bonding system was used to bond the same type of metal brackets to all the teeth. The teeth were then stored in distilled water for 48 hours. An Instron Testing Machine was used to measure shear bond strength in Megapascals. The Analysis of Variance was used to compare the three groups.
The comparisons of the shear bond strength for incisors (x=12.4+6.5 MPa), premolars (x=11.9+5.2 MPa) and third molars (x=13.1+6.2 MPa) indicted that they were not significantly different (p=0.84). In conclusion, the findings indicate that in vitro testing of bond strength is not significantly agecte.9y the use of various tooth types namely, incisors, premolars and molars. This finding suggests that investigators can use teeth that are more readily available e.g. third molars to test bond strength.
Request for reprints:Dr. S.E Bishara, Dept. of Orthodontics, 220 Dental Science 5, Iowa City, Iowa 52242-1001, U.S.A.