Comparative study of tubular diameter and quantity for human and bovine dentin at different depths

This study compared the tubular dimensions and distribution of human and bovine dentin. Ten human molars and 10 bovine incisors were ground with a high-speed handpiece to obtain 3 sections at different dentin depths (superficial, middle and deep). The specimens were sputter-coated with gold to be examined under scanning electron microscopy (SEM). Three SEM micrographs were recorded randomly for each dentin depth. The number of tubules was counted and the diameter of 5 tubules selected at random was measured in each SEM micrograph. Data were analyzed statistically by ANOVA and Tukey's test (a=0.05). In bovine teeth, superficial dentin (4.21 μm) and middle dentin (3.98 μm) had a significantly greater (p<0.05) diameter than deep dentin (3.14 μm) tubules. In human teeth, superficial dentin tubule diameter (2.42 μm) was significantly smaller (p<0.05) than deep dentin (2.99 μm) and middle dentin (2.94 μm) tubule diameters, which did not differ significantly from each other (p>0.05). The number of tubules per square millimiter, regardless of the region, was significantly greater in human dentin (22,329) than in bovine dentin (15,964). There was a clear difference in tubule structure and morphology between human and bovine dentin.

Este estudo comparou a dimensão e a distribuição tubular da dentina humana e bovina. Dez molares humanos e 10 incisivos bovinos foram desgastados com alta rotação para se obter 3 secções de diferentes profundidades de dentina (superficial, média e profunda). As amostras foram cobertas com ouro em um metalizador para a observavação em MEV. Três micrografias foram tiradas aleatoriamente para cada profundidade de dentina. O número de túbulos foi contado e o diâmetro de 5 túbulos selecionados aleatoriamente foi medido para cada micrografia. Os resultados foram submetidos à análise de variância e ao teste de Tukey (a=0.05). Em dente bovino, a dentina superficial (4,21 μm) e a dentina média (3,98 μm) apresentaram diâmetro estatisticamente superior (p<0,05) à dentina profunda (3,14 μm). Em dente humano, o diâmetro dos túbulos da dentina superficial (2,42 μm) mostrou-se significativamente menor que a dentina profunda (2,99 μm) e média, (2,94 μm) as quais não diferiram entre si. O numero de túbulos por mm2, independente da região, foi significativamente maior para a dentina humana (22,329) que para dentina bovina (15,964). Houve uma clara diferença na estrutura tubular e morfológica entre dentina humana e bovina.

The effect of miswak and tooth brush filaments end-surface texture on enamel. A SEM pilot study.

OBJECTIVE: The aim of the study was to compare the abrasive effect of miswak and toothbrush filaments on enamel tooth surface. MATERIAL AND METHODS: Ten maxillary central incisors were obtained from Division of Maxillofacial Surgery, King Saud University, College of Dentistry. Twenty specimen were prepared, they were divided into 4 groups (1) Butler toothbrush; (2) Aquafresh toothbrush; (3) Miswak; (4) Control group. Miswak, Aquafresh 311 and Butler 311 tooth brush were used with light pressure in one direction motion for 60 seconds on enamel surface. The specimens were prepared for Scanning Electron Microscopy (SEM) examination. The middle filament from toothbrushes and miswak were also prepared for SEM. RESULTS: Showed that filaments end-surface texture play a major role in abrasive active activity and enamel tooth surface loss. CONCLUSION: The Butler 311 toothbrush and miswak showed lesser effect on enamel as compared to Aquafresh 311 toothbrush.