[A study on the rate of collagenase in the degradation of human root dentin in vitro].
OBJECTIVE
The purpose of this study was to evaluate the effect of degradation of human root dentin collagen treated with collagenase after demineralization.


METHODS
The root dentin samples were demineralized by incubating with PH5.0 lactate acid at 37 degrees C. The incubation solutions were taken on days 1, 7, 14, 21 and 28, and centrifuged 10,000r/min at 4 degrees C. The supernature solutions were analyzed for Ca(2+) and hydroxyproline. The demineralized root samples were incubated with PH7.4 collagenase solution for 7 days at 37 degrees C. The incubation solutions were centrifuged 10,000r/min at 4 degrees C and analyzed for hydroxyproline.


RESULTS
The release of Ca(2+) increased and had significant differences at all observation periods within 28 days (P<0.05). There were no significant differences of the amount of degradable collagen during the nonenzymatic procedure (P>0.05). The amount of collagenase-degradable collagen was proportional to the calcium released until a plateau value at a calcium loss of about 80.01 micromol/cm(2) was reached.


CONCLUSIONS
The degradability of collagenase is in close association with calcium released. The retention of mineral is of relevance for lesion arrestment or remineralization of early root caries.
School of Dentistry, Shandong University, Jinan 250012, China.
Duo
D
Wang
Wei-shan
WS
Ding
Ai-ling
AL
Huang
Zhu-ping
ZP
Wang