Title of article :
Nanoindentation hardness of intertubular dentin in sound, demineralized and natural caries-affected dentin
Author/Authors :
Joves، نويسنده , , Gerardo José and Inoue، نويسنده , , Go and Sadr، نويسنده , , Alireza and Nikaido، نويسنده , , Toru and Tagami، نويسنده , , Junji، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2014
Pages :
7
From page :
39
To page :
45
Abstract :
The purpose of this study was to investigate the mechanical properties of intertubular dentin in sound, natural caries-affected (NCAD) and artificial caries-affected dentin (ACAD) using nanoindentation. als and methods ries molars and caries molars with International Caries Detection and Assessment System (ICDAS II) score 5 at the occlusal site were used and caries was excavated using a spoon excavator, a round bur at low speed without water and a dye solution as guidance to detect the infected tissue. Specimens with remaining dentin thickness (RDT) >2 mm were selected. ACAD teeth were created from sound teeth over 7 days in a demineralizing solution. Specimens were embedded into plastic rings with acrylic resin and then sagittal mesial–distal sectioned from crown to the long axis of the root under cooling water using a low-speed diamond blade. The surface of interest was fine polished sequentially. Hardness measurement was performed within an axial depth of 1000 μm with at least of 320 indentations on each sample. Mann–Whitney U Test was used to compare the hardness as the variable among different dentin types (SOUND, NCAD and ACAD) at each dentin depth level. s was no significant difference in nanohardness between NCAD and ACAD up to a depth of 130 μm (p>0.05). NCAD consistently showed lower hardness. ACAD showed no significant difference in hardness with SOUND dentin beyond 190 μm (p<0.05). The lesion front in ACAD was considered to be located around the depth of 180 μm. sion l and artificial caries-affected dentin tissues were superficially comparable in intertubular nanohardness. There is a certain layer within the natural caries-affected dentin with higher hardness; however the long-term effects of caries beneath the lesion extend deeply through intertubular dentin. Sound dentin at deep areas (close to the pulp chamber) is considered to be soft.
Keywords :
nanohardness , Caries-affected dentin , Sound dentin , Remaining dentin thickness , Artificial caries-affected dentin
Journal title :
Journal of the Mechanical Behavior of Biomedical Materials
Serial Year :
2014
Journal title :
Journal of the Mechanical Behavior of Biomedical Materials
Record number :
1406445
Link To Document :
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