Improving fissure sealant quality: mechanical preparation and filling level

To assess the effect of different modes of fissure preparation and filling level on the quality of pits and fissure sealants.

Various modes of fissure preparation in combination with two filling levels were examined. A total of 90 caries-free extracted human molar teeth were divided into three groups according to fissure preparation: (a) no mechanical preparation; (b) mechanical preparation with a round carbide bur; and (c) mechanical preparation with a tapered fissure diamond bur. All fissures were acid-etched and each group was subdivided according to filling level, either to the border or overfilled, using Helioseal (Vivadent, Schaan, Lichtenstein) as a sealant material. A modified microleakage assay was performed, combining occlusal loading and thermocycling, prior to staining with 0.5% Basic Fuchsin. After sectioning, teeth were examined and photographed in a reflected light microscope, sealant retention was observed and recorded. Microleakage and sealant penetration depths were measured for each section. Two-way ANOVA was used for statistical analysis.

Sealant penetration and retention were significantly improved by mechanical preparation compared to non-prepared fissures (p<0.0001), and preparation with a tapered fissure diamond bur was superior to the round carbide bur. Overfilled fissures caused significantly higher levels of microleakage (p<0.004).

Based on the results of this in vitro study, it is suggested that fissure sealant quality may be improved by mechanical preparation, preferably with a tapered diamond bur, and filling just to the border. Overfilling of fissures should be avoided.