Multicenter randomized trial on dental prosthetic therapies for the shortened dental arch – 15-year follow-up and evaluation of the 10- and 15-year examination time

随着预防和微创治疗策略的不断变化，人们越来越倾向于保留功能上可接受的缩短牙弓(SDA)。由于缺乏大量证据的数据，2000年开始了一项多中心随机对照临床试验--“随机缩短牙弓研究”，以比较两种治疗方案。患者接受部分可拆卸义齿(PRPD)治疗，或者通过保留或修复前磨牙而导致牙弓缩短(SDA)。从迄今所取得的10年结果来看，可拆卸和固定义齿在这组患者中没有显示出任何差异。根据目前的结果，这两种治疗方案都可以被归类为临床上合理的概念。在第一个10年结果的背景下，(1)部分可移除牙修复体--当看手头的研究中的精密附着体修复体--既不能被判断为第二选择治疗方案，也不能(2)放弃磨牙替换被判定为有缺陷。因此，科学验证的知识表明，在这个患者队列中，患者的选择在共同决策中必须特别重要。此外，牙周健康作为修复治疗成功的辅助因素的高影响可以得到证实。部分可摘牙修复体的限制因素是更高的随访努力。针对两个特定治疗概念的多中心临床试验首次在全球范围内成功地进行了如此长的时间跨度。到目前为止，关于这个主题的最热门的综述[Khan S，Musekiwa A，Chikte UM，OmarR]对于接受修复治疗和未治疗的成人患者的功能结果的差异：一项系统的综述。PLOS一号。2014年7月3日；9(7)：E101143。DOI：10.1371/Joural.pone.0101143]仍然指出，持续缺乏最高水平的研究和关于不同治疗方案存活率的陈述。这一知识差距应通过对RASDA研究患者的持续后续治疗、现有数据的补充、高级研究以及对初级和次级研究结果的全面生物测定分析来弥合。

The ongoing change in paradigm towards preventive and minimal invasive treatment strategies increasingly favors the preservation of a functionally acceptable shortened dental arch (SDA). As data on a high level of evidence were missing, in the year 2000 the “Randomized shortened dental arch study” - a multicenter randomized controlled clinical trial - was started in order to compare two treatment options.Patients were treated with either partial removable dental prostheses (PRPD) or alternatively by preserving or restoring the premolars resulting in a shortened dental arch (SDA).In the light of the 10-year results achieved so far, removable and fixed dental prostheses do not show any difference in this patient collective. Based on the present results, both treatment options can be classified as clinically sound concepts.Against the background of the first 10-year results(1) partial removable dental prostheses – when looking at the precision attachment prostheses in the study at hand – can neither be judged as second-choice therapynor can(2) renouncing molar replacement be judged as being deficient.Thus, scientifically validated knowledge shows that patients’ choice has to be of particular importance in shared decision making in this patient cohort. Furthermore, the high impact of periodontal health as co-factor for the success of prosthodontic therapy could be confirmed.Limiting factor for partial removable dental prostheses is the higher follow-up effort.A multicenter clinical trial on two specific treatment concepts with such a patient collective was successfully carried out worldwide for the first time over such a long time span.The so far most topical review on this subject [Khan S, Musekiwa A, Chikte UM, Omar R. Differences in functional outcomes for adult patients with prosthodontically-treated and -untreated shortened dental arches: a systematic review. PLoS One. 2014 Jul 3;9(7):e101143. doi: 10.1371/journal.pone.0101143] still states a persisting lack of highest evidence level studies and missing statements on the survival of the different treatment options.This knowledge gap shall be closed with the ongoing follow-up treatment of the RaSDA study patients, with complementing the existing data, with an advanced investigation, and with the comprehensive biometrical analysis of the primary and secondary study outcomes.