Physical Properties of the Dentin of Deciduous and Permanent Teeth

Objectives: There is still little research and information on the precise composition and the micromorphology of the dentin of deciduous teeth, and the existing literature reveals controversial findings. The results of studies in permanent teeth are frequently extrapolated to deciduous teeth, and the majority of works explores these substrates alone. It is thus necessary to know the composition and structure of the dentin of deciduous teeth and determine in which ways this tissue actually differs from the dentin of permanent teeth. Comparison of these substrates under different aspects is fundamental to establish preventive and restorative protocols, as well as materials and techniques that are specific and effective for deciduous and permanent teeth. Therefore, the aim of the present in vitro study was to perform a comparative analysis of the dentin of deciduous and permanent teeth.

Methods: The physical properties were evaluated by the tests: Permeability (n=15), Radiodensity (n=10) and Ultimate Tensile Strength (n=15). Data distribution and homogeneity were analyzed. Thus, one-way analysis of variance (type of substrate) was used for the Permeability and Radiodensity tests (p<0.05); two-way analysis of variance (type of substrate and depth) was used for the Microtensile Bond Strength test (p<0.05).

Results: Considering the limitations of an in vitro investigation, the findings revealed that with respect to the physical properties, the dentin of deciduous teeth presented greater permeability, lower radiodensity and lower ultimate bond strength of substrate when compared with the dentin of permanent teeth.

Conclusions: Therefore, the dentin of deciduous teeth presented different physical properties compared to the permanent teeth.