| The application of a silicon composite to the base of orthodontic brackets has been studied. The effects of the silicon on bond strength and adhesive retention to the bracket upon debonding were evaluated. Thirty extracted mandibular first premolars were randomly divided into two groups. Group I consisted of teeth bonded with Ormco Mini DiamondTM (Camden, MA) brackets with a stainless steel, mesh base, (control), and Group 2 consisting of teeth bonded with the TP Nu-edgeTM line of brackets with the silicon composite base.;The brackets were debonded with a shear force in the occlusogingival direction using an InstronTM Universal Testing Machine (Instron, Canton, MA) at a crosshead speed of .5mm/minute. The results were recorded in kilograms and converted to megapascals for comparison. Each bracket was also observed under magnification to evaluate the amount of adhesive remaining on the bracket after debond.;No significant difference was found between the two groups for bond strength when using a independent groups West for analysis. There was however, a clinically significant difference between the two groups when comparing the amount of adhesive remaining on the tooth after debond. The TP brackets clearly retain a larger amount of the adhesive on the bracket after debonding compared to the Ormco bracket. |
