Scanning electron microscopy study of the fitting surface of fissure sealants.

The bond strength between enamel and resin depends on achieving an etching pattern on the enamel surface which allows the resin to penetrate into the enamel and form tags. Silverstone et al. (1975) have described three basic etching patterns of human dental enamel using phosphoric acid solution. Type I etching pattern is related to the removal of the prism core material with the prism peripheries remaining relatively unaffected. In the Type 2 etching pattern, the peripheral regions of prism are removed, leaving prism cores relatively intact. The Type 3 etching pattern corresponds to a generalized enamel surface roughening. Failures in sealant retention have been attributed to the following: contamination of the etched enamel with saliva and/or oil, residual organic or inorganic substances on the enamel surface, inherent properties of the sealant, improper handling of resin material, and/ or excessive occlusal load on the sealant. In addition, fissure morphology (Galil and Gwinnett 1975a; Juhl 1983) and failure of etching liquid to reach enamel because of debris in the fissure have been postulated (Taylor and G winnett 1973; Burrow and Makinson 1990) and may help to explain a large number of sealant failures. The purpose of the present study was to observe enamel resin tags in teeth with sealed fissures using a replication technique.