Quantitative changes in fissure sealant six months after placement.

Earlier studies have reported extensive volumetric loss of fissure sealant shortly after placement. To determine the volume of fissure sealant lost at six months, we used a servohydraulic profilometric apparatus in combination with computer graphics. Twenty-two premolar teeth were selected, and baseline silicone impressions were made of each tooth. The teeth were sealed and the occlusion adjusted where necessary. Impressions were made immediately of sealed teeth and again at six months. Epoxy replicas were made from all impressions, and their surfaces digitized by sequential profilometry. Using a three-dimensional root mean square (RMS) goodness-of-fit computer program, before sealant, after sealant, and six months after sealant computer-graphic images were superimposed. The volume of sealant lost after six months for all premolar teeth was X = 0.23 mm3 (maxillary second premolar: N = 9, X = 0.29 mm3; maxillary first premolar: N = 5, X = 0.27 mm3; mandibular second premolar: N = 4, X = 0.20 mm3; mandibular first premolar: N = 4, X = 0.08 mm3). The volume differences between tooth groups were not significant as measured by analysis of variance (ANOVA). These volumes represented a 13.99% loss of applied sealant for all premolars (maxillary second premolar: 19.72%; maxillary first premolar: 15.37%; mandibular second premolar: 8.46%; mandibular first premolar: 6.37%). The area of wear and the depth of wear also were measured.