A Study of the Effectiveness of Topical Fluoride Treatment Following the Removal of Direct Bonded Brackets

Abstract

In this investigation an attempt was made to determine what effect direct bonded attachments have on the posttreatment uptake of topically applied fluoride. Thirty-two freshly extracted mandibular central and lateral incisors were used. The teeth were cleaned, labeled and an adhesive tape window applied to the crown exposing a circular area one quarter inch in diameter on the labial surface. An initial enamel biopsy was performed to determine the fluoride content of the labial surface. Fifty percent phosphoric acid was applied for one minute to condition the teeth for bonding. A polycarbonate orthodontic bracket was then bonded with Sevriton resin and each tooth was stored for one week in water. After storage, the brackets were then removed and residual resin was cleaned off with a dental scaler. Half of the teeth were pumiced with flour of pumice for ten seconds. The teeth were observed microscopically to determine the condition of the labial surface. A 2% solution of sodium fluoride was applied to the teeth for eight minutes and the samples were then individually stored in water for one week. An enamel biopsy was performed and analyzed for fluoride, calcium, and phosphorus. A great deal of fluoride was taken up by the enamel surface on all the specimens. It was found that pumicing the teeth prior to the application of topical fluoride results in a significantly greater uptake of fluoride by the enamel surface. The results of this investigation indicate that a pumice wash following bracket removal facilitates a greater and more uniform uptake of topically applied fluoride on the surface of the teeth.