EFFECT OF PUMICE PROPHYLAXIS ON THE BOND STRENGTH OF ORTHODONTIC BRACKETS

Pumice prophylaxis has long been accepted as a prerequisite for achiev ing adequate enamel etching during orthodontic bonding procedures. Thr ee methods were used in this study to examine the effects of pumice pr ophylaxis on the bond strength of orthodontic brackets: (1) shear bond strength of brackets that were bonded to extracted premolars after su rface preparation procedures, which either included or did not include prior pumice prophylaxis, was evaluated; (2) scanning electron micros copy (SEM) was used to examine the surface characteristics of teeth th at had been etched with and without prior pumice prophylaxis; and (3) rate of bracket failure in patients who had had brackets bonded with a nd without prior pumice prophylaxis was recorded during an average tre atment time of 18 months. No significant differences were noted in bon d strength, general etched enamel surface characteristics, or bracket retention rates. Some specific differences, however, were noted on SEM in localized areas of the etched enamel surfaces, although these did not appear to affect the bond strength or bracket retention rates ulti mately attained.