Abstract：
OBJECTIVE: This 2-year prospective study reports the incidence of prosthetic complications and maintenance events after treatment with mandibular overdenture retained by four mini implants opposed to a maxillary denture.
METHODS: Implant intervention included flapless or flapped surgery combined with immediate or delayed loading, as part of a randomized clinical trial. Four one-piece titanium-zirconium mini-implants (Straumann Mini Implant System) were inserted, and the retentive PEEK elements (Optiloc) were incorporated into the overdenture using chairside procedures. Prosthodontic complications and maintenance events were recorded over a 2-year follow-up, and the final outcome was defined according to standardized criteria. Data analysis included descriptive statistics, incidence and incidence density rates, and Kaplan-Meier survival.
RESULTS: 73 out of 74 patients (64.9 % female), mean age of 64 (SD=8.2) years, completed the study follow-up (one withdrew after 9 months). Implant survival was 100 %. A total of 163 prosthodontic events occurred in 53 patients (72.6 %), and 20 patients had no clinical complaints or maintenance needs. The most common procedures were adjustment/repair of the overdenture base (47.0 %), replacement of retentive inserts (19.8 %), and laboratory relining (12.9 %). A high prosthodontic success rate was achieved (93.2 %), and all patients presented serviceable overdentures and continuous use after the resolution of prosthodontic complications. The incidences of matrix replacement and laboratory relines were low in the first year, while denture base adjustments were common within the first year, especially in the first 6 months.
CONCLUSIONS: The mini implant system showed high prosthodontic success rates. Minor adjustments/repairs during the initial follow-up were common. Relines and matrix replacements tend to occur after one year of overdenture use, and matrix replacements may occur as a consequence of the need for relining.
METHODS: Implant intervention included flapless or flapped surgery combined with immediate or delayed loading, as part of a randomized clinical trial. Four one-piece titanium-zirconium mini-implants (Straumann Mini Implant System) were inserted, and the retentive PEEK elements (Optiloc) were incorporated into the overdenture using chairside procedures. Prosthodontic complications and maintenance events were recorded over a 2-year follow-up, and the final outcome was defined according to standardized criteria. Data analysis included descriptive statistics, incidence and incidence density rates, and Kaplan-Meier survival.
RESULTS: 73 out of 74 patients (64.9 % female), mean age of 64 (SD=8.2) years, completed the study follow-up (one withdrew after 9 months). Implant survival was 100 %. A total of 163 prosthodontic events occurred in 53 patients (72.6 %), and 20 patients had no clinical complaints or maintenance needs. The most common procedures were adjustment/repair of the overdenture base (47.0 %), replacement of retentive inserts (19.8 %), and laboratory relining (12.9 %). A high prosthodontic success rate was achieved (93.2 %), and all patients presented serviceable overdentures and continuous use after the resolution of prosthodontic complications. The incidences of matrix replacement and laboratory relines were low in the first year, while denture base adjustments were common within the first year, especially in the first 6 months.
CONCLUSIONS: The mini implant system showed high prosthodontic success rates. Minor adjustments/repairs during the initial follow-up were common. Relines and matrix replacements tend to occur after one year of overdenture use, and matrix replacements may occur as a consequence of the need for relining.
摘要：
目的：这项为期2年的前瞻性研究报告了使用四个微型种植体保留的下颌覆盖义齿治疗后修复并发症和维护事件的发生率。
方法：种植体干预包括无瓣或拍打手术，同时立即或延迟负重，作为随机临床试验的一部分。插入四个一体式钛锆微型植入物（Straumann微型植入物系统），并使用椅旁程序将保留性PEEK元素（Optiloc）结合到覆盖义齿中。在2年的随访中记录了口腔修复并发症和维护事件，根据标准化标准定义最终结局.数据分析包括描述性统计，发病率和发病率密度率，和Kaplan-Meier的生存.
结果：74例患者中有73例（64.9%为女性），平均年龄64岁（SD=8.2），完成了研究随访(其中一个在9个月后退出).植入物存活率为100%。共发生163例口腔修复事件53例（72.6%），20例患者无临床主诉或维持需求.最常见的手术是调整/修复覆盖义齿基托（47.0%），保留插入件的更换(19.8%)，和实验室换层(12.9%)。达到了较高的修复成功率（93.2％），所有患者都提供了可使用的覆盖义齿，并在修复并发症解决后继续使用。第一年基质置换和实验室反应的发生率很低，虽然义齿基托调整在第一年很常见，尤其是前6个月。
结论：微型种植体系统显示出较高的修复成功率。初始随访期间的小调整/修理是常见的。在使用覆盖义齿一年后，往往会发生换牙和基质置换，由于需要重新衬砌，可能会发生矩阵替换。
方法：种植体干预包括无瓣或拍打手术，同时立即或延迟负重，作为随机临床试验的一部分。插入四个一体式钛锆微型植入物（Straumann微型植入物系统），并使用椅旁程序将保留性PEEK元素（Optiloc）结合到覆盖义齿中。在2年的随访中记录了口腔修复并发症和维护事件，根据标准化标准定义最终结局.数据分析包括描述性统计，发病率和发病率密度率，和Kaplan-Meier的生存.
结果：74例患者中有73例（64.9%为女性），平均年龄64岁（SD=8.2），完成了研究随访(其中一个在9个月后退出).植入物存活率为100%。共发生163例口腔修复事件53例（72.6%），20例患者无临床主诉或维持需求.最常见的手术是调整/修复覆盖义齿基托（47.0%），保留插入件的更换(19.8%)，和实验室换层(12.9%)。达到了较高的修复成功率（93.2％），所有患者都提供了可使用的覆盖义齿，并在修复并发症解决后继续使用。第一年基质置换和实验室反应的发生率很低，虽然义齿基托调整在第一年很常见，尤其是前6个月。
结论：微型种植体系统显示出较高的修复成功率。初始随访期间的小调整/修理是常见的。在使用覆盖义齿一年后，往往会发生换牙和基质置换，由于需要重新衬砌，可能会发生矩阵替换。
