根面再石灰化の初期過程におけるミネラル量の変化 単一切片法と画像定量法による評価

Abstract

Early remineralization in root surfaces with cementum was evaluated by conbining a single-section technique with videodensitometry.A total of 10 root sections 125-μm thick were cut individually from 10 samples of freshly extracted sound human premolars and coated with nail varnish leaving a window on the cementum surfaces. After demineralization by immersion in 0.01M lactate buffer (6mM Ca, 3.6mMP, 1% CMC, pH 5.1) at 37°C for 48 hours, all specimens were immersed in remineralizing solution (3mM Ca, 1.8mMP, 150mM NaCl, 2ppm F, 1% CMC, pH 7.0) at 37°C for 7 days. The changes in mineral volume were assessed quantitatively by videodensitometry for the microradiographs prepared before and after remineralization.Results were as follows:(1) Approximately half the mineral volume accumulated during the 7-day remineralization was acquired whthin the first 2days. This fact indicates that the degree of remineralization in root surfaces progresses rather rapidly.(2) From the digitized microradiographic images, initial remineralizing sited appeared to be located in the subsurface layer of cementum.(3) We suggest that the degree of in vitro remineralization should be evaluated within a short period when a seingle-section technique is used.