Microleakage of a universal adhesive used as a fissure sealant

To evaluate the microleakage of a universal hydrophilic adhesive (OptiBond dual-cure) by itself as a pit and fissure sealant compared to that of an ionomeric product (VariGlass) and two hydrophobic sealants (Delton and Fluroshield).

Sixty-four extracted human third molars were sealed with one of these four materials under either a conventional procedure (free of humidity) or after contamination of the etched surfaces with 3 microliters of human plasma. The sealed teeth were subjected to 1,500 thermocycles (1 min/5-55 degrees C) and to 450,000 mechanical cycles under an 8.5 kgf average load at 37 degrees C. The tooth crowns were partially coated with nail varnish, immersed in a 50% aqueous solution of AgNO3 for 2 h in darkness, washed and then developed for 8 h under fluorescent light. The teeth were sectioned and dye penetration was scored according to a 4-point scale by four trained professionals.

An ANOVA suggested that under no humidity conditions, the average score for VariGlass (1.92 +/- 0.36) was significantly higher (P = 0.0006) than that corresponding to the three remaining materials (1.28 +/- 0.20) which were considered equivalent. Under humid (plasma contaminated) conditions, there was complete loss of Delton and Fluroshield in all cases, whereas the average score for VariGlass (1.98 +/- 0.36) was slightly higher (P = 0.0444) than that for OptiBond (1.62 +/- 0.36). These results suggest that OptiBond may be used by itself as a pit and fissure sealant instead of the combination of adhesive plus sealant.