Hoppenbrouwers P M, Driessens F C, Borggreven J M
Dental School, University of Nijmegen, The Netherlands.
Arch Oral Biol. 1987;32(5):319-22. doi: 10.1016/0003-9969(87)90085-9.
Whole roots of molars that had never been exposed to the mouth were exposed to calcium and phosphate-containing buffer solutions with discrete values of pIOHA [i.e. -log(a10Ca2+ X a6PO4(3-) X a2OH-)] at various pH. From densitometric measurements on contact-microradiographs of transverse sections of the roots the rate of demineralization (Vdem) was calculated. Vdem changed non-linearly as a function of pIOHA and became zero at a pIOHA-value of 105.3 +/- 0.4; this is substantially lower than the corresponding value of 118 +/- 1 for enamel. Thus root mineral is more soluble than enamel mineral. The critical pH for root caries appears to be about 6.7, provided that the plaque fluid follows about the same pH-pIOHA- pathway as acidified saliva.
将从未暴露于口腔的磨牙的完整牙根，置于含有不同pIOHA值[即-log(a10Ca2+×a6PO4(3-)×a2OH-)]的钙和磷酸盐缓冲溶液中，溶液pH各不相同。通过对牙根横切面接触式显微放射照片进行密度测量，计算出脱矿速率（Vdem）。Vdem随pIOHA呈非线性变化，在pIOHA值为105.3±0.4时变为零；这一数值远低于牙釉质相应的118±1。因此，牙根矿物质比牙釉质矿物质更易溶解。如果菌斑液的pH-pIOHA途径与酸化唾液大致相同，那么牙根龋的临界pH似乎约为6.7。
