Self-etching primers with and without pre-etching : comparison with conventional acid etching technique

الملخص EN

Objectives: To compare the bond strength between brackets bonded with conventional and self-etching primers (SEPs) with and without pre-etching and to evaluate the mode of bracket/tooth bond failure.

Methods: A total of 125 freshly extracted premolar teeth were randomly assigned into equal 5 groups at which enamel surfaces were prepared for brackets bonding.

2 main groups were compared against 3 experimental groups for shear bonding strength (SBS) testing.

The first group (Control); consisted of the conventional bonding protocol while the second group (SEP) included enamel conditioning with SEP.

The experimental groups; (10-SEP), (20-SEP) and (30-SEP), involved preceded steps of different pre-etching times.

Upper incisor brackets were bonded for all teeth.

A shear force at the bracket-tooth interface was applied to debond the brackets.

The enamel surface of each tooth was examined to determine the amount of residual adhesive on each tooth.

All statistical tests were performed at P <0.05.

Results: There were no significant differences between SBS values of the 2 main groups and between these 2 groups and the 10-and 20-SEP groups.

The 30-SEP group showed statistically higher mean values compared to the main groups.

The risk of leaving the adhesive at the tooth surface was increasing with the increase in the pre-etching time with the group 30-SEP having the highest percentage.

Conclusion: There were no differences in the bond strength between the conventional and the SEP bonding protocols.

The addition of 30 seconds as a pre-etching SEP step maximized the bond strength with more resin remained at the tooth surface after debonding