Department of Prosthodontics and Oral Rehabilitation, Osaka University Graduate School of Dentistry, Osaka, Japan.
J Prosthet Dent. 2010 Mar;103(3):178-81. doi: 10.1016/S0022-3913(10)60026-1.
While 2 to 4 implants are preferred to retain and stabilize an implant overdenture, some reports suggest a single implant is adequate to retain an overdenture. Denture fracture is one of the common complications with overdentures; however, there is no information on the incidence of fractures when dentures are retained by 1 implant.
The purpose of this study was to compare the fracture incidence of mandibular overdentures retained by 1 and 2 implants.
The records of 85 subjects enrolled in the Vancouver Implant Prosthesis (VIP) clinical trial between 2003 and 2008 and followed up for at least 17 months were reviewed retrospectively. From the clinical records, subjects who had experienced a fractured overdenture were identified. A fracture was considered as either a visible crack in the acrylic resin or complete separation of the denture parts. The same clinical records listed 3 denture fracture sites: over the implant, elsewhere, or unknown. A chi-square test was used to compare the incidence of fracture (alpha=.05). Kaplan-Meier and log rank tests were used to compare the survival rate of overdenture or "time to fracture" (alpha=.05).
Forty-two subjects received a single implant, and 43 received 2 implants. In total, there were 17 fractures recorded for 13 subjects. Nine single-implant subjects experienced 11 denture fractures, while 4 double-implant subjects experienced 6 fractures. There was no significant difference in the incidence of denture fractures in prostheses retained by 1 or 2 implants. When denture fractures did occur, they were found most frequently in areas adjacent to the implant(s).
The incidence of denture base fractures was not significantly different between overdentures retained by 1 implant and those retained by 2 implants. When fractures did occur, they tended to be in areas adjacent to implants.
虽然 2 到 4 个种植体被认为是保留和稳定种植体覆盖义齿的理想选择,但有报道称单个种植体也足以保留覆盖义齿。义齿折断是覆盖义齿的常见并发症之一;然而,关于单个种植体保留的义齿发生折断的发生率尚无信息。
本研究旨在比较单个和两个种植体保留的下颌覆盖义齿的折断发生率。
回顾性分析了 2003 年至 2008 年期间参加温哥华种植体修复体(VIP)临床试验并至少随访 17 个月的 85 名受试者的记录。从临床记录中,确定了经历义齿折断的受试者。义齿折断被认为是丙烯酸树脂出现可见裂纹或义齿部分完全分离。同一临床记录列出了 3 个义齿折断部位:种植体上方、其他部位或未知部位。采用卡方检验比较折断发生率(α=.05)。采用 Kaplan-Meier 和对数秩检验比较覆盖义齿的存活率或“折断时间”(α=.05)。
42 名受试者接受了单个种植体,43 名受试者接受了两个种植体。共有 13 名受试者记录了 17 次义齿折断。9 名单种植体受试者发生 11 次义齿折断,4 名双种植体受试者发生 6 次折断。1 个种植体和 2 个种植体保留的义齿折断发生率无显著差异。当义齿确实发生折断时,最常见于种植体附近的区域。
1 个种植体保留的覆盖义齿和 2 个种植体保留的覆盖义齿的义齿基托折断发生率无显著差异。当发生折断时,倾向于发生在种植体附近的区域。