RESUMEN
The purpose of this investigation was to study by scanning electron microscope the effect of strontium chloride [Sensodyne toothpaste] and Nd:YAG laser on exposed dentinal tubules of human sensitive extracted teeth. The teeth were sectioned longitudinally into two halves and classified into three groups. Group I was treated with Sensodyne, group II was laser-treated and the third group was used as control group. The specimens were mounted on a stab, sputtder coated by gold and examined by scanning electron microscope. SEM observation of the dentin showed that the orifices of the dentinal tubules in hypersensitive areas [control] were open and wide and its lumens were empty. In the Sensodyne-treated teeth [group I], most of the dentinal tubules were occluded with crystals of all sizes. The observable effects of laser irradiation occurred to be as actual melting and recrystallization at the dentin which appeared to be non-porous and continuous in nature. The analysis of the data indicated the use of Sensodyne [strontium chloride] as a desensitizing agent which provides an excellent example of how drugs or chemicals can work in treating dentin sensitivity. The data also indicated how Nd:YAG laser works to modify the dentin surface and occlude the openings of the dentinal tubules. Such a dentin surface modification may be accepted in the future as treatment modality, since the melting and resolidification of the dentin and the closure of the tubules may be permanent and not short-lived