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Microhardness of superficial and deep sound human dentin
Author(s) -
Fuentes Victoria,
Toledano Manuel,
Osorio Raquel,
Carvalho Ricardo M.
Publication year - 2003
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.10064
Subject(s) - knoop hardness test , materials science , dentin , indentation hardness , indentation , vickers hardness test , composite material , molar , adhesive , dentistry , microstructure , layer (electronics) , medicine
Our purpose in this study was to determine the microhardness of superficial and deep dentin by means of two indentation methods (Knoop and Vickers) under two different applied loads. Twelve dentin discs approximately 2‐mm thick were obtained from both superficial and deep dentin by transversally sectioning the crowns of sound, extracted human third molars with a diamond blade under water irrigation. Dentin surfaces were sequentially polished, and indentations ( n = 20 per surface) were performed with either Vickers indentor at loads of 300 and 500 g, respectively, or Knoop indentor at loads of 50 and 100 g, respectively. Average Vickers hardness number (VHN) and Knoop hardness number (KHN) were calculated and treated with two‐way analysis of variance (ANOVA) and Student's t test. Microhardness of dentin was not influenced by the different loads applied for both indentation methods. Knoop hardness was significantly higher for superficial than for deep dentin ( p < 0.05). Conversely, Vickers hardness was not significantly different for both substrates ( p > 0.05). Differences in dentin hardness as a function of depth exist, but they might not be relevant, and no alteration of the distribution of stresses along the adhesive interface is expected. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 850–853, 2003