Orthodontic microabrasive reproximation.

Reproximation (enamel stripping) is described in the literature as a clinical procedure for correction of tooth size deviations. The objective of this study was to qualitatively assess, by means of scanning electron microscopy, (1) the differences exhibited on enamel with mechanical and chemical methods of stripping, and (2) the effect of a synthetic calcifying solution on the etched enamel. Part 1. Sixty human anterior teeth (10 complete sets) that were previously stored in 70% ethanol were subdivided into groups I and II. The teeth in group I were divided into five sets of six teeth mounted in a plaster block in the anterior arch form. Each set was stripped with one of the following mechanical abrasive methods: garnet disks, tungsten carbide and fine diamonds burs, coarse and fine diamond burs, diamond wheel and 3M strips, diamond-coated metal and 3M strips. The teeth in group II were similarly treated, except each set was subjected to a further microabrasive chemical stripping with 37% phosphoric acid used in conjunction with 3M strips. The teeth were then prepared for scanning electron microscopy, viewed, and photographed under magnification. Part 2. Ten human central incisor teeth were etched and used to study the effect of remineralization solutions at various time intervals. The results showed that teeth stripped by routine mechanical abrasive methods exhibited deep furrows and roughness. The teeth that received mechanical and chemical abrasive treatments showed a flattened, etched surface free of furrows. These etched surfaces showed marked crystal growth at 5 and 10 hours after remineralization suggesting the possibility of repair of the chemically altered enamel surface.