TY - JOUR
T1 - Denaturation Temperatures of Dentin Matrices. I. Effect of Demineralization and Dehydration
AU - Armstrong, Steven R.
AU - Jessop, Julie L P
AU - Winn, Erik
AU - Tay, Franklin Chi Meng
AU - Pashley, David Henry
PY - 2006/7/1
Y1 - 2006/7/1
N2 - The denaturation temperature (Td) of dentin collagen in mineralized versus demineralized teeth was examined as a function of dentin age and the extent of dehydration. Using differential scanning calorimetry, Td of mineralized dentin was shown to be between 160°C to 186°C, depending on whether it was from young or old dentin that was hydrated or dehydrated, respectively. Demineralized dentin exhibited a Td of 65.6°C that increased with dehydration to 176°C. The presence of apatite crystallites or interpeptide bonding increased the Td of demineralized matrices. Interpeptide hydrogen bonding seems to stabilize collagen to thermal challenge. Water breaks interpeptide hydrogen bonds making collagen more susceptible to thermal denaturation. Rises in intracanal temperature are unlikely to cause extensive denaturation of mineralized root dentin walls. However, hydrated or partially dehydrated root canal walls that have been partially demineralized with chelating agents or mild acids may be susceptible to thermal denaturation.
AB - The denaturation temperature (Td) of dentin collagen in mineralized versus demineralized teeth was examined as a function of dentin age and the extent of dehydration. Using differential scanning calorimetry, Td of mineralized dentin was shown to be between 160°C to 186°C, depending on whether it was from young or old dentin that was hydrated or dehydrated, respectively. Demineralized dentin exhibited a Td of 65.6°C that increased with dehydration to 176°C. The presence of apatite crystallites or interpeptide bonding increased the Td of demineralized matrices. Interpeptide hydrogen bonding seems to stabilize collagen to thermal challenge. Water breaks interpeptide hydrogen bonds making collagen more susceptible to thermal denaturation. Rises in intracanal temperature are unlikely to cause extensive denaturation of mineralized root dentin walls. However, hydrated or partially dehydrated root canal walls that have been partially demineralized with chelating agents or mild acids may be susceptible to thermal denaturation.
KW - Collagen
KW - dentin
KW - differential scanning calorimetry
KW - glass transition
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U2 - 10.1016/j.joen.2005.10.062
DO - 10.1016/j.joen.2005.10.062
M3 - Article
C2 - 16793470
AN - SCOPUS:33745224529
VL - 32
SP - 638
EP - 641
JO - Journal of Endodontics
JF - Journal of Endodontics
SN - 0099-2399
IS - 7
ER -