Microleakage and SEM evaluation of fissure sealants placed by use of self-etching priming agents

Objectives. This study evaluated the microleakage and internal seal of fissure sealants placed by use of self-etching priming agents in comparison to phosphoric acid etching of enamel. Methods. Seventy-two caries-free extracted human molars were divided into six groups with 12 teeth each. Occlusal surfaces were cleansed by either pumicing (Groups I, III, V) or by 15-s air-abrasion treatment with 25 μm aluminum oxide particles (Groups II, IV, VI). Fissures were sealed with the self-etching priming systems, Clearfil Liner Bond 2 (Groups I, II) or Resulcin AquaPrime (Groups III, IV). In Groups V and VI, sealants were placed after phosphoric acid etching. Half of the teeth in each group were thermocycled. After staining with 0.5% methylene blue, the teeth were sectioned for evaluation of microleakage. Internal adaptation of the fissure sealants was analyzed by SEM on replicas of cross sections. Results. Independent of the methods used for cleansing of the occlusal surfaces, fissure sealants in Groups I and II showed significantly more microleakage and less sufficient internal seal as compared to sealants placed in Groups III to VI. Sealants placed by Resulcin AquaPrime (Groups III, IV) leaked significantly more than sealants applied after phosphoric acid etching (Groups V, VI) of the enamel. However, statistical analysis (H-test) did not reveal significant differences concerning the internal adaptation of sealants placed in Groups III, IV, V and VI. Conclusions. Concerning the microleakage data, use of the self-etching bonding systems, Clearfil Liner Bond 2 and Resulcin AquaPrime, cannot be recommended for fissure sealing, since the sealing ability is less effective as compared to the conventional acid-etching technique.