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

预防性和微创治疗策略的范式正在发生变化，越来越倾向于保留功能上可接受的缩短牙弓（SDA）。由于缺少高水平证据的数据，2000年开始的“随机缩短牙弓研究”--一项多中心随机对照临床试验--旨在比较两种治疗方案。患者接受部分可摘义齿（PRPD）治疗或保留或修复前磨牙导致牙弓缩短（SDA）。根据10-到目前为止，活动和固定假牙在这一患者群体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。在前10年结果的背景下，（1）部分可摘义齿-当观察手头研究中的精密附着体义齿时-既不能被判断为第二选择疗法，也不能（2）放弃磨牙替换被判断为有缺陷。因此，经科学验证的知识表明，患者的选择在该患者队列的共同决策中具有特别重要的意义。此外，牙周健康作为修复治疗成功的辅助因素的高度影响可以得到证实。部分可移除牙科修复体的限制因素是较高的随访努力。在如此长的时间跨度内，首次在全球范围内成功地进行了关于两种特定治疗概念的多中心临床试验。放大图片作者：Musekiwa A，Chikte UM，Omar R.接受修复治疗和未接受修复治疗的牙弓缩短成人患者功能结果的差异：一项系统综述。PLoS One. 2014年7月3日;9（7）：e101143。土井：10.1371/journal.pone.0101143]仍然指出持续缺乏最高证据水平的研究，并且缺少关于不同治疗方案生存率的声明。这种知识差距应通过对RaSDA研究患者的持续随访治疗，通过补充现有数据，通过先进的研究，以及主要和次要研究结果的综合生物统计学分析。

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.