The Tensile Bond Strength of Fissure Sealant to Enamel Treated by Nd-YAG Laser Irradiation with TiO2 Suspension

Abstract

In pediatric dentistry, treatment is performed mainly for oral health care and prevention of caries. Fissure sealants are often used in clinical practice for prevention of dental caries. The prevention of caries in occlusal fissures is of practical importance, since pits and fissures are more susceptible to caries than any area. It is possible to debride pits and fissures using laser irradiation in order to remove the fissure contents without altering the shape and structure of the fissures. Although the adhesive strength of fissure sealant to enamel may grow weak when a laser is used, there have been no reports regarding the adhesive strength of enamel to fissure sealant after Nd-YAG laser irradiation with 1% TiO2 suspension. Therefore, the authors investigated the tensile bond strength of a commercial fissure sealant applied after Nd-YAG laser irradiation in contact mode with a fiber diameter of 400 μm, 5 pps, laser tip output power of 300 mJ, and with the use of 1% TiO2 suspension. It was revealed that lasers could react to an enamel surface without any special treatment like application of a black pigment to the surface of the tooth when Nd-YAG laser irradiation was performed. Also, the tensile bond strength of TeethmateF1® to the enamel was lower after laser irradiation with 1% TiO2 suspension, whereas that of Fuji III LC® was stable. From the SEM images of the interfaces between the fissure sealant and enamel, it was found that the enamel surface was affected to a depth of approximately 20-30 μm by laser irradiation. It was revealed that when the fissure sealant was applied with laser irradiation, the laser should be precisely irradiated and the use of a glass-ionomer fissure sealant was more effective.