DOI: 10.36347/sjams.2018.v06i10.024

Pages: 3787-3794

In an attempt to minimize bond failures, orthodontists have sought out ways to ensure adequate bond strengths while still maintaining an efficient procedure with the least invasive method of bonding. Enamel loss with acid etching ranges from 3-10µ. These limitations have led to the search for newer, enamel friendly technique for surface preparations. To evaluate & compare the effects of different concentrations of phosphoric acid, self-etch primer and air abrasion on the surface characteristics of enamel and shear bond strength .100 extracted premolar teeth were divided in to 5 groups (20 teeth in each group) and etched with different etchants (Group I -2%H3PO4, Group II-15% H3PO4, Group III -37% H3PO4, Group IV- Sand blasting and Group V- Self etching Primer) .After etching tooth surface was studied under SEM. Then the brackets were bonded and shear bond strength was measured by universal testing machine. Group III (37% phosphoric acid) & Group V(Self-etching primer) showed less destruction to the enamel surface as compared to other groups during SEM study. Maximum SBS was found for group III (13.73+0.25 MPa) followed by Group II (11.74+0.27 MPa), Group V (10.29+0.24 MPa), GroupI (8.31+0.26 MPa) and Group IV (7.40+0.26 MPa). 37% phosphoric acid and Self- Etching primer were found more favorable etching agent. 37% phosphoric acid and 15% phosphoric acid can be used for etching the enamel surface to get maximum shear bond strength as compared to other surface treatment methods.