Comparing the tensile strength of brackets adhered to laser-etched enamel vs. acid-etched enamel.

This study compared the tensile bond strength of brackets adhered to laser-etched enamel with that of brackets adhered to acid-etched enamel. Forty extracted, intact bovine teeth were treated with either 37 percent phosphoric acid for 15 seconds or neodymium:yttrium-aluminumgarnet laser on black-ink-coated enamel. After thermocycling, tensile stress was applied to the bonded specimens at a 0.1 millimeter/minute orosshead speed. A t-test comparison of means showed a significant difference between the laser-etched and acid-etched teeth, with the acid-etched teeth demonstrating significantly more tensile bond strength at a 95 percent level of significance.