Effect of Removal of Enamel on Rebonding Strength of Resin Composite to Enamel

Table 3

Bond strengths (MPa) of the composite to enamel after the first bonding and rebonding. Enamel substrate has been ground for 0, 10, 20, and 30 seconds (s) and the corresponding removal of enamel is given in micrometers (μm). Surface roughness after acid etching of the ground enamel substrate is given as value of average surface roughness (R_a).

	G0	G1	G2	G3
Grinding time	0	10	20	30
Thickness of removed enamel	—	7 (±2)	12 (±1)	16 (±3)
Surface roughness (one specimen)	0.301	1.945	0.857	0.343
Bond strength (1st bonding)	19.4 (±5.2)	15.7 (±5.2)	17.5 (±4.9)	20.3 (±5.9)
Bond strength (rebonding)	14.3 (±3.6)	16.1 (±3.3)	16.3 (±4.8)	18.0 (±4.3)

An asterisk indicates statistical difference () between values.