The objective of this experiment was to compare the shear bond strengths of a self-limiting etchant to a standard etchant system at 15-, 30-, 60-, 90-, and 120-second enamel etching time intervals.The facial surfaces of 150 bovine maxillary incisors were mounted and etched with one of two different etchants (Dentsply 34% Phosphoric Acid or Opal Orthodontics Opal Etch 35%, a self-limiting phosphoric acid) at varying timed intervals of 15, 30, 60, 90, and 120 seconds. The teeth were then primed, cured, and bonded with resin rods. Shear bond strength and fracture mode were recorded.The results of the two-way ANOVA found that Opal Etch had significantly greater bond strengths to enamel compared with the control etchant (P < 0.001). Ninety seconds of etching time resulted in the greatest bond strength for both groups, but was not significantly different from 30 seconds; 120 seconds had the lowest bond strength to enamel in both groups, but was not significantly different from 15 seconds. A one-way ANOVA was performed per etchant. A Bonferroni correction was applied because multiple comparisons were completed (α = 0.025). For the Opal Etch, a significant difference was found based on time (P = 0.007).The shear bond strength of Opal Etch consistently tested higher than the Dentsply etchant, but was not found to be self-limiting.