Avaliação in vitro da microdureza de dentina bovina normal e esclerosada In vitro evaluation of the microhardness of normal and sclerotic bovine dentin

Introduction: The literature shows different characteristics between normal and sclerotic dentin. Hardness is a property that has been very used to compare restorative materials and biological tissues. Objective: The aim of this study was to compare the hardness clinical characteristics between the normal and the sclerotic bovine dentin, through the microhardness test. Material and methods: 20 bovine teeth were divided in two groups: GI (normal) and GII (with characteristics of sclerosis). The teeth were mounted in acrylic resin cylinders with exposure of dentin along the incisal edges. The specimens received finishing and polishing following by storage in distilled water at ambient temperature for 7 days. Microhardness measurements were made using a Vickers indenter microhardness tester under a load of 50 gf for 45 s. In this study 3 areas per specimen were selected and each area received 5 indentations, resulting in 15 indentations per specimen. Results: The data were statistically processed using the Student’s t-test. The level of significance was 5%. The results showed no significant differences between the mean values of the two groups (GI: 36.82±9.45; GII:32.4±12.2) (p = 0.383). Conclusion: The normal bovine dentin presented similar microhardness Vickers values to the sclerotic bovine dentin.