Hoppenbrouwers P M, Groenendijk E, Tewarie N R, Driessens F C
Dental School, University of Nijmegen, The Netherlands.
J Dent Res. 1988 Oct;67(10):1254-6. doi: 10.1177/00220345880670100101.
Roots of extracted human molars were treated for both 10 and 30 min with a saturated solution of dicalcium phosphate dihydrate (DCPD) of pH 2.4 and subsequently with a 5.3 mmol.L-1 solution of sodium fluoride of pH 7.0. The objective of these combined treatments was to convert the highly-soluble root mineral into the less-soluble fluoridated hydroxylapatite, with DCPD as an intermediate, to improve caries resistance. The mineral content of the surface layer was not affected in a significant way. Roots treated in this way were subjected to 50 mmol.L-1 acetate buffer solutions of pH 5.5 and with pIOHA-values of 112, 116, and 122. The proportional reduction of the rate of demineralization (Vdem) of similarly treated roots subjected to buffer solutions of pIOHA 112 and 116 appeared to be equal initially. Since fluoridated hydroxylapatite is insoluble under these conditions, these findings are in agreement with expectations. The reduction of V dem amounted to about 45 and 70% for roots treated for 10 and 30 min, respectively. When roots were treated for 10 and 30 min and then exposed to buffer solutions with a pIOHA 122, reductions of V dem of about 30 and 55%, respectively, were found. Conversion of the root mineral into fluoridated hydroxylapatite can eliminate, in principle, the existing difference in caries susceptibility of the root and of the dental enamel.
将拔除的人类磨牙牙根用pH值为2.4的二水磷酸二钙（DCPD）饱和溶液处理10分钟和30分钟，随后用pH值为7.0的5.3 mmol·L⁻¹氟化钠溶液处理。这些联合处理的目的是以DCPD作为中间体，将高溶解性的牙根矿物质转化为低溶解性的氟羟基磷灰石，以提高抗龋性。表层的矿物质含量未受到显著影响。以这种方式处理的牙根置于pH值为5.5且pIOHA值分别为112、116和122的50 mmol·L⁻¹乙酸盐缓冲溶液中。暴露于pIOHA为112和116的缓冲溶液中的经类似处理的牙根，脱矿速率（Vdem）的初始比例降低似乎相等。由于氟羟基磷灰石在这些条件下不溶，这些发现与预期相符。处理10分钟和30分钟的牙根，Vdem的降低分别约为45%和70%。当牙根分别处理10分钟和30分钟，然后暴露于pIOHA为122的缓冲溶液中时，发现Vdem的降低分别约为30%和55%。将牙根矿物质转化为氟羟基磷灰石原则上可以消除牙根和牙釉质在龋易感性方面现有的差异。
