Background: Acid etching results in an unintentional demineralization of the enamel surface, while laser conditioning might provide microspaces which then remineralize by trapping free ions; thus enhancing resistance to caries. Since, Systemp desensitizer was very successful in reducing the incidence of post-operative pain; consequently, this in-vitro study was designed to evaluate the effect of Systemp on the surface micro roughness and permeability of enamel following two different techniques of enamel etching; acid and laser etching; in premolar teeth.
Methodology: Fifty freshly extracted non-carious premolar teeth were used. The teeth were divided into 5 groups each containing 10 teeth. Group I: control group, group II: teeth exposed to phosphoric acid etching. Group III: teeth exposed to low level laser (LLL) etching. Group IV: Systemp applied to acid etched enamel. Group V: Systemp applied to teeth etched by LLL. The extent of dye penetration was measured using stereo-microscopy and the obtained data were statistically analyzed. The surfaces of the specimens were examined using scanning electron microscopy.
Results: scanning electron microscopic (SEM) examination of group II revealed an obviously porous enamel surface with type III enamel etching pattern. On the other hand, following laser etching, enamel surface showed areas of non removed prismless enamel while most enamel presented type I enamel etching pattern. Systemp application rendered the surface more homogenous especially in the acid etched group. Statistical analysis revealed that the distance travelled by the dye was significantly greater in group II (acid etched group) (mean±SD=1,406.06±0.721), than group III (laser etched group) (mean±SD=1,235.35±0.771). However, group IV (Systemp applied to acid etched enamel) (mean±SD=1,078.47±0.634) showed significant reduction than group V (Systemp applied to LLL etched enaamel) (mean±SD=1,198.44±0.583) as the p-value was less than 0.05.
Conclusion and recommendations: despite laser advantages, laser-etching applications should be improved. Besides, desensitizing agents, like Systemp, could be efficient in sealing etched enamel surface, which could reduce sensitivity resulting from leakage through enamel into the underlying dentin.