Ayanoglou C M, Lesty C
Laboratoire Biologie et Biomatériaux du Milieu Buccal et Osseux, Faculté de Chirurgie Dentaire, Université Paris V, Montrouge, France.
J Periodontal Res. 1997 Oct;32(7):614-8. doi: 10.1111/j.1600-0765.1997.tb00939.x.
The aim of the present investigation was to examine if new cementum (NC) formed during cyclosporin A (CsA) administration was maintained after suspension of the treatment. Thirty mg/kg/d of CsA were given to 3 male Sprague-Dawley rats. Three control rats received oil-based vehicle solution. Nine wk later the drug and vehicle administration were stopped and the rats continued to be fed with the same standard laboratory diet and water ad libitum for 5 months. The rats were anaesthetized, the tissues fixed by intracardiac perfusion of fixative solution and the mandibles processed for Epon inclusion. Histological, histomorphometric and ultrastructural analysis revealed that (a) NC covered extensive areas of the root surfaces; its structural characteristics were identical to those observed in the rats killed during CsA administration. (b) collagen fibres of the adjacent connective tissue were functionally inserted into the NC. (c) In the presence of cervical NC spurs the extent of the apical downgrowth of the junctional epithelium, measured parallel to the cemento-dentinal junction, was decreased (up to 64%) compared to the one occurring in areas devoid of NC deposits. These results suggest that (a) NC deposition and its functional relations with the adjacent connective tissue are not reversible after cessation of CsA treatment and (b) in the presence of cervical NC spurs the amount of connective tissue attachment on the root surfaces is increased.
本研究的目的是检测在给予环孢素A（CsA）期间形成的新牙骨质（NC）在治疗停止后是否得以维持。给3只雄性Sprague-Dawley大鼠每日给予30mg/kg的CsA。3只对照大鼠接受油基赋形剂溶液。9周后停止给药和赋形剂处理，大鼠继续随意给予相同的标准实验室饮食和水，持续5个月。将大鼠麻醉，通过心脏内灌注固定液固定组织，并将下颌骨处理后包埋于环氧树脂中。组织学、组织形态计量学和超微结构分析显示：（a）NC覆盖牙根表面的广泛区域；其结构特征与在给予CsA期间处死的大鼠中观察到的相同。（b）相邻结缔组织的胶原纤维功能性地插入NC中。（c）在存在颈部NC刺的情况下，与无NC沉积区域相比，平行于牙骨质-牙本质界测量的结合上皮根尖向下生长的程度降低（高达64%）。这些结果表明：（a）CsA治疗停止后，NC沉积及其与相邻结缔组织的功能关系不可逆；（b）在存在颈部NC刺的情况下，牙根表面结缔组织附着量增加。
