Relationship between Hardness, Discoloration, and Microbial Invasion in Carious Dentin

Abstract

SYNOPSIS IN INTERLINGUA LE RELATION INTER LE DURITATE, LE DISCOLORATION, E LE INVASION MICROBIAL IN DENTINA CARIOSE.-Frescamente extrahite dentes con carie esseva dissecate verticalmente. In un del partes le superficie sectional esseva examinate pro duritate secundo Knoop e discoloration. Sectiones histologic del altere parte esseva usate pro le detection de evidentia microbiotic. Le resultatos esseva le sequentes: In dentina cariose, mollification precedeva in omne casos le discoloration, e invasion microbial esseva semper le tertie stadio. Le duritate de dentina in le fronte discolorate o microbial esseva inferior in casos acute e superior in casos chronic. Le distantia inter ille frontes e le fronte de mollification esseva plus grande in casos acute e plus micre in casos chronic.

Microhardness of superficial and deep sound human dentin

“…The calculated mean value for Knoop hardness is also similar to previously reported values, ranging from 50 to 70. [15][16][17] The similarity of reported values is certainly due to the reproducible microindentation techniques employed. 1 Although a hardness-load dependence sometimes exists for brittle materials, no significant hardnessload dependence was detected for either the Vickers or Knoop tests within the test load ranges.…”

“…20 -25 KHN) for deep dentin. 16,24,25 Such differences are attributed to the mode of specimen preparation. Our values were taken as an average of indentations made on the entire surface of a disc obtained from deep dentin.…”

“…Their measurements were made on longitudinal sections. 16 Because the tubules in dentin are not randomly oriented, properties may be directionally dependent.…”

Bond Strengths of a 1-Step Self-etching System to Caries-affected and Normal Dentin

“…Microhardness of normal dentin ranged from 54-74 KHN and that of cariesaffected dentin ranged from 26-45 KHN, both of which are in accordance with previously reported studies. 1,6,10,14 Therefore, specimens that contained caries in affected dentin (<25 KHN) or both normal and cariesaffected dentin within the tested area were deleted from the study. Caries-affected dentin is known to show lower hardness values due to the loss of mineral from intertubular dentin.…”

“…Extensive cavity preparations have been replaced by more conservative techniques, with removal of the infected, permanently damaged caries tissue only, preserving the bacteria-free, cariesaffected dentin or sclerotic dentin. 1 Caries-affected dentin contains intrinsic properties that are different from normal dentin, such as reduced permeability because of formation of whitlockites within the dentinal tubules and a partially demineralized intertubular dentin. [2][3] Ideally, in order to maximally preserve the tooth substrate, the clinical bonding substrate should be caries-affected dentin.…”