Foster L V
Department of Conservative Dentistry, University of Bristol Dental School.
Br Dent J. 1994 Aug 6;177(3):89-93. doi: 10.1038/sj.bdj.4808518.
Eighty patients were selected, who were each deemed to require the replacement of a defective amalgam restoration. The patients had a mean age of 36.7 years and were dentally fit on average 40 months previously. The main reasons given for the replacement of the defective restorations were perceived radiographic secondary caries (31%), fracture of the restoration (20%), marginal defect (17%), and perceived secondary caries observed clinically (14%). Following the removal of the restorations, a highly significant relationship was found between the consistency and colour of the underlying dentine (P < 0.00001). Soft dentine was found underlying 36 (88%) of the 41 defective amalgam restorations which were diagnosed as having caries associated with them. However, hard dentine was found underlying only 19 (49%) of the 39 teeth where no caries had been diagnosed. The presence of soft dentine where not anticipated was mainly in association with fractured restorations (11 out of 16). Younger patients were more likely to have soft dentine underlying their defective amalgam restorations than older patients (P = 0.005). No relationship was found between the presence of corrosion products on the cavity walls associated with defects and the consistency of the underlying dentine.
选取了80名患者，他们均被认为需要更换有缺陷的汞合金修复体。这些患者的平均年龄为36.7岁，平均在40个月前牙齿状况良好。更换有缺陷修复体的主要原因是影像学检查发现继发龋（31%）、修复体折断（20%）、边缘缺损（17%）以及临床观察到的继发龋（14%）。去除修复体后，发现底层牙本质的硬度和颜色之间存在高度显著的相关性（P < 0.00001）。在41个被诊断与龋病相关的有缺陷汞合金修复体中，有36个（88%）的下方发现了软质牙本质。然而，在39颗未诊断出龋病的牙齿中，只有19个（49%）的下方发现了硬质牙本质。未预期到的软质牙本质的存在主要与修复体折断有关（16个中有11个）。年轻患者比年长患者更有可能在有缺陷的汞合金修复体下方出现软质牙本质（P = 0.005）。在与缺损相关的洞壁上存在腐蚀产物与底层牙本质的硬度之间未发现相关性。
