Morphology and microhardness of dentin at the furcation area of mandibular molars
| Autor: | Jesus Djalma Pécora, Antônio Miranda Cruz-Filho, Luis Eduardo Souza Flamini |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Molar
Materials science Morphology (linguistics) Scanning electron microscope Dentistry Mandible stomatognathic system Hardness Dentin medicine Humans Cementum Tooth Root General Dentistry Dental Cementum Orthodontics MOLAR business.industry stomatognathic diseases medicine.anatomical_structure Dentinal Tubule Microscopy Electron Scanning Knoop hardness test Dental Pulp Cavity business Layer (electronics) |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Introduction: This study evaluated dentin morphology and microhardness at the furcation area of mandibular molars. Methods: Toothsegmentsofmandibularmolars were embedded in resin blocks and bisected longitudinally (n = 20), and the furcation area was delimited by tracing 2 orthogonal lines from the most concave point of the outer surface of the furcation toward the mesial anddistalcanalentrances.Inhalfofthespecimens,Knoop microhardness was measured in 2 directions in the furcation area: vertically, parallel to the orthogonal lines and thebisectoroftheangleformedbythem;andhorizontally, inthe outer (closeto the pulpchamberfloor),inner (close to the cementum), and middle dentin layers. Data were analyzed statistically by one-way analysis of variance and Tukey-Kramer test (a = 0.05). The other half of the specimens were examined by scanning electron microscopy to evaluate dentin morphology and trajectory of thetubules. Results: Nostatisticallysignificantdifference (P>.05)wasfoundamongthemesial(46.56.4),central (47.3 8.1),and distal (49.7 6.5)orthogonal lines. The inner dentin layer (51.7 2.5) was statistically similar to the middle (46.3 2.9) (P > .05), which was similar to the outer layer (41.4 2.4) (P > .05). The inner layer was significantly harder than the outer layer (P < .05). The morphologicanalysis revealeda tendency ofcalcification of the tubules from the outer toward the inner layer. Conclusions: Dentin microhardness at the furcation area is uniform in its 3 vertical axes, but the inner dentin layer is harder than the outer layer. The dentinal tubules follow a centripetal direction toward the inner layer, in which dentin is much more mineralized. (J Endod 2014;40:129‐132) |
| Databáze: | OpenAIRE |
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