Schwindling Franz Sebastian, Dittmann Britta, Rammelsberg Peter
Assistant Professor, Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany.
Private practice, Mering, Germany.
J Prosthet Dent. 2014 Sep;112(3):488-93. doi: 10.1016/j.prosdent.2014.02.017. Epub 2014 May 13.
Research data are scarce on double-crown-retained removable dental prostheses. In double-crown-retained removable dental prostheses, crown-like copings are definitively cemented to the abutment teeth and serve as prosthesis attachments.
The purpose of this study was to evaluate the survival of double-crown-retained removable dental prostheses in use for 7 years and to determine their most common complications.
A retrospective analysis was conducted to investigate the clinical outcome of 117 prostheses in 86 patients with 385 abutment teeth. Thirty-two telescopic-crown-retained removable dental prostheses, 51 conical-crown-retained removable dental prostheses, and 34 resilient telescopic-crown-retained overdentures were clinically reexamined by 1 investigator. Prosthesis success was defined as survival without severe complications (abutment tooth extraction). Statistical analyses were performed with Kaplan-Meier modeling and Cox regression (α=.05).
Minor complications, for example, the decementation of primary crowns (34.2%), failure of the veneer of secondary crowns (11.1%), fracture of the denture base (17.1%), and the need for relining (12%), were common. Cumulative prosthesis survival for all types of prostheses was 93.8% after 7 years. After the same period, prosthesis success was 90% for telescopic-crown-retained removable dental prostheses and 78.5% for conical-crown-retained removable dental prostheses and resilient telescopic-crown-retained overdentures.
The medium-term double-crown-retained removable dental prosthesis survival found in this retrospective investigation appears acceptable. When bearing in mind the limits of this study, this kind of prosthesis might be a viable treatment option for patients with a reduced dentition. However, more laboratory and clinical research is necessary to reduce the incidence of minor complications and confirm the present in vivo results in larger patient groups.
关于双冠固位可摘义齿的研究数据较少。在双冠固位可摘义齿中，冠状顶盖被永久粘固于基牙上并作为义齿的附着体。
本研究的目的是评估使用7年的双冠固位可摘义齿的存留率，并确定其最常见的并发症。
进行一项回顾性分析，以调查86例患者中117件义齿和385颗基牙的临床结果。由1名研究者对32件套筒冠固位可摘义齿、51件圆锥冠固位可摘义齿和34件弹性套筒冠固位覆盖义齿进行临床复查。义齿成功定义为无严重并发症（基牙拔除）的存留。采用Kaplan-Meier模型和Cox回归进行统计分析（α=0.05）。
常见轻微并发症，如初级冠的松动（34.2%）、次级冠的饰面失败（11.1%）、义齿基托折断（17.1%）以及重衬的需求（12%）。7年后所有类型义齿的累积存留率为93.8%。同期，套筒冠固位可摘义齿的义齿成功率为90%，圆锥冠固位可摘义齿和弹性套筒冠固位覆盖义齿的成功率为78.5%。
在这项回顾性研究中发现的中期双冠固位可摘义齿存留率似乎可以接受。考虑到本研究的局限性，这种义齿可能是牙列缺损患者的一种可行治疗选择。然而，需要更多的实验室和临床研究来降低轻微并发症的发生率，并在更大的患者群体中证实目前的体内研究结果。
