Valderhaug J, Birkeland J M
J Oral Rehabil. 1976 Jul;3(3):237-43. doi: 10.1111/j.1365-2842.1976.tb00949.x.
The oral hygiene, gingival condition, pocket depth and loss of attachment were studied during a period of 5 years in a group of patients (114) who had been treated with fixed dental protheses. Eighty-four per cent of the subjects had received periodontal therapy prior to the prosthetic treatment. During the study the subjects participated in an oral hygiene programme. Crown margins were located sub-gingivally, at the gingiva, and supra-gingivally. Initially 65% of the crown margins were sub-gingival compared to 41% 5 years later. When the crown margins were located sub-gingivally there was an increase in Gingival Index scores 2 and 3, in pocket depth, and in loss of attachment compared to a supragingival placement. However, most of the alterations were small.
在一组接受固定义齿修复治疗的114例患者中，对其口腔卫生、牙龈状况、牙周袋深度和附着丧失情况进行了为期5年的研究。84%的受试者在修复治疗前接受过牙周治疗。在研究期间，受试者参与了一项口腔卫生计划。冠边缘位于龈下、龈缘和龈上。最初，65%的冠边缘位于龈下，而5年后这一比例为41%。与冠边缘位于龈上相比，当冠边缘位于龈下时，牙龈指数2级和3级、牙周袋深度及附着丧失均有所增加。然而，大多数变化较小。
