Different Adhesives On The Braces Off Tooth Surface And The Influence Of The Bonding Strength

ObjectiveTo compare the effects of different adhesives on shear bond strength of orthodontic brackets with rebonded teeth which were bonded with different different adhesives.MethodsOne hundred and eighty extracted human premolars were randomly divided into9groups (n=20). For group Al, A2and A3, the premolar brackets were bonded with Jingjin enamel adhesive system; for group B1, B2and B3, the premolar brackets were bonded with GC Fuji ORTHO LC adhesive system; for group C1, C2and C3, the premolar brackets were bonded with3M Transbond XT adhesive system. After being exposed to artificial saliva for24h, all of the brackets were removed by shear bond strength. The largest shear bond strength was measured, and the adhensive remnant index was recorded. Then, for group Al, B1and C1, the brand new premolar brackets were bonded with Jingjin enamel adhesive system; for group A2, B2and C2, the brand new premolar brackets were bonded with GC Fuji ORTHO LC adhesive system; for group C1, C2and C3, the brand new premolar brackets were bonded with3M Transbond XT adhesive system. Finally, after being exposed to artificial saliva for24h, the brackets were removed by shear bond strength. The largest shear bond strength was measured, and the adhensive remnant index was recorded.Results①The mean shear bond strength for the group Al, A2and A3were:(9.16±2.48)MPa,(11.84±4.51)MPa and (14.56±3.80)MPa. There were significant differences between the three groups in shear bond strength (P<0.05), and for the pairwise comparisons, there were significant differences for each pair (P<0.05). There were significant differences between the three groups in the adhensive remnant index (P<0.05), and the index in group A3was significantly greater than group A1and A2. for the pairwise comparisons, there were significant differences for each pair (P<0.05).②The mean shear bond strength for the group B1, B2and B3were:(12.81±4.42)MPa,(8.28±3.06)MPa and (13.22±3.17)MPa. There were significant differences between the three groups in shear bond strength (P<0.05). For the pairwise comparisons, there were significant differences for group B1and B2(P<0.05), B2and B3(P<0.05); there were no significant differences for group B1and B3(P>0.05). There were significant differences between the three groups in the adhensive remnant index (P<0.05), and the index in group B2was significantly less than group B1and B3.③The mean shear bond strength for the group C1, C2and C3were:(6.90±2.50)MPa,(10.57±3.23)MPa and (13.52±5.14)MPa. There were significant differences between the three groups in shear bond strength (P<0.05), and for the pairwise comparisons, there were significant differences for each pair (P<0.05). There were significant differences between the three groups in the adhensive remnant index (P<0.05), and the index in group C3was significantly greater than group C1and C2..Conclusion①For the rebounded teeth which were bonded with Jingjin enamel adhesive system before,3M Transbond XT system can offer the largest shear bond strength, and it should be the preferred.②For the rebounded teeth which were bonded with GC Fuji ORTHO LC adhesive system before, Jingjin enamel adhesive system and3M Transbond XT adhesive system can both offer a larg shear bond strength.③For the rebounded teeth which were bonded with3M Transbond XT adhesive system before,3M Transbond XT adhesive system can offer the largest shear bond strength, and it should be the preferred.④Either adhesive systems were used for the first time bonding, when rebonding on the teeth surface brackets off,3M Transbond XT adhesive system can offer the largest shear bond strength.