Firestone A R, Graves C, Caufield P W, Feagin F F
J Dent Res. 1987 Oct;66(10):1583-6. doi: 10.1177/00220345870660101401.
We studied the effect of oral infection with cariogenic micro-organisms on alveolar bone loss and root surface caries subsequent to gingivectomy in rats. Thirty-six rats were fed diet MIT 200 (67% sucrose); one-half, the controls, had antibiotics added to the diet. At ages 18, 19, and 21 days, the experimental group was orally infected with streptomycin-resistant Streptococcus sobrinus (mutans) 6715 and Actinomyces viscosus M-100. At age 30 days, all animals were subjected to a gingivectomy on maxillary and mandibular left quadrants. The experimental group was re-inoculated at age 36 days. Animals were killed seven weeks after surgery. Jaws were stained, and planimetric measurements of exposed root surface area and caries on lingual/palatal surfaces of 1st and 2nd molars were made from video images with a computer/digitizer. Compared with the non-operated contralateral quadrants, gingivectomy significantly increased exposed root surface area in the maxilla and in the mandible in both the control and experimental groups. Oral inoculation significantly increased exposed root surface in mandibular (but not maxillary) quadrants which had received a gingivectomy, but had no effect on non-gingivectomized quadrants. There was no caries in the control group, whereas ten rats in the experimental group had root surface caries lesions, all in quadrants which had received a gingivectomy. This rat model should prove useful in further studies of root surface caries.
我们研究了致龋微生物经口感染对大鼠牙龈切除术后牙槽骨丧失和根面龋的影响。36只大鼠喂食MIT 200饮食（67%蔗糖）；其中一半作为对照组，在饮食中添加了抗生素。在18、19和21日龄时，实验组经口感染耐链霉素的远缘链球菌（变形链球菌）6715和黏性放线菌M - 100。在30日龄时，所有动物的上颌和下颌左象限均接受牙龈切除术。实验组在36日龄时再次接种。术后7周处死动物。对颌骨进行染色，并通过计算机/数字化仪从视频图像中对第一和第二磨牙舌侧/腭侧表面暴露的根表面积和龋损进行平面测量。与未手术的对侧象限相比，牙龈切除术显著增加了对照组和实验组上颌和下颌的暴露根表面积。经口接种显著增加了接受牙龈切除术的下颌（而非上颌）象限的暴露根表面积，但对未进行牙龈切除术的象限没有影响。对照组没有龋损，而实验组有10只大鼠出现根面龋损，均在接受牙龈切除术的象限。该大鼠模型在根面龋的进一步研究中应会证明是有用的。
