Purpose: To assess quantitatively the influence of salivary contamination in vitro on marginal microleakage of pit and fissure sealants.
Methods: Forty-eight sound human third molars were selected and assigned to three groups: 1) Fluroshield (F), 2) Single Bond + Fluroshield (SBF) and 3) Ketac-fil (KF). Each group was divided into two subgroups: control (C) and with salivary contamination (SC). The occlusal surfaces were etched with 40% polyacrylic acid for 10 seconds or 37% phosphoric acid for 30 seconds, for either glass-ionomer or resin-based sealants, respectively. Specimens were contaminated with 0.25 mL of fresh human saliva for 20 seconds and dried afterwards. The sealants were placed and samples were thermocycled, immersed in a 0.2% Rhodamine B solution for 24 hours, embedded in acrylic resin and serially sectioned. The sections were viewed under an optical microscope connected to a computer and a video camera, and the images obtained were digitized. The extent of dye penetration along buccal and lingual slopes was measured in millimeters, using specific computer software, and converted into percentage, according to the fissures extension.
Results: The microleakage means (%) were: F/C:0 (+/- 0); F/SC: 31.71 (+/- 31.69); SBF/C: 0 (+/- 0); SBF/SC: 0 (+/- 0); KF/C: 0.98 (+/- 2.79) and KF/SC: 11.82 (+/- 15.45). ANOVA and Tukey test showed that salivary contamination provided significant increase in microleakage. Under salivary contamination, only SBF provided complete marginal sealing. When F and KF were compared, the glass-ionomer cement yielded the best sealing.