Takahashi Toshihito, Gonda Tomoya, Maeda Yoshinobu
Int J Oral Maxillofac Implants. 2017 November/December;32(6):1308–1314. doi: 10.11607/jomi.5737. Epub 2017 Sep 22.
Implant overdentures with attachments have been used in clinical practice and the effect of attachments on implant strain has been frequently reported. However, most studies have focused on mandibular overdentures; there are few reports on maxillary overdentures. The purpose of this study was to examine the influence of attachment type on implant strain in maxillary overdentures under various implant configurations.
A maxillary edentulous model with implants and experimental overdentures were fabricated. Four strain gauges were attached to each implant, positioned in anterior, premolar, and molar areas. Three types of unsplinted attachments-ball, locator, and magnet-were set on the implants under various implant configurations. A vertical occlusal load of 98 N was applied through the mandibular complete denture, and implant strain was compared using the Kruskal-Wallis test.
Ball attachments caused the greatest amount of strain, while magnet attachments caused the least amount under all conditions. For all attachments, two anterior implants caused significantly more strain than four implants (P < .05). No significant difference was observed between subtypes in four-implant configurations except when using locator attachments.
When using unsplinted attachments for maxillary implant overdentures, magnet attachments are recommended to reduce implant stress. Using only two implants, especially two anterior implants, is not recommended regardless of attachment type.
带有附着体的种植覆盖义齿已应用于临床实践,且附着体对种植体应变的影响已有诸多报道。然而,大多数研究集中在下颌覆盖义齿;关于上颌覆盖义齿的报道较少。本研究的目的是探讨在各种种植体配置下,附着体类型对上颌覆盖义齿种植体应变的影响。
制作带有种植体的上颌无牙颌模型及实验性覆盖义齿。在每个种植体上附着四个应变片,分别位于前部、前磨牙区和磨牙区。在各种种植体配置下,在种植体上设置三种类型的非夹板式附着体——球帽、Locator附着体和磁性附着体。通过下颌全口义齿施加98 N的垂直咬合载荷,并使用Kruskal-Wallis检验比较种植体应变。
在所有情况下,球帽附着体产生的应变最大,而磁性附着体产生的应变最小。对于所有附着体,两个前部种植体产生的应变明显大于四个种植体(P <.05)。在四种植体配置中,除使用Locator附着体时外,各亚型之间未观察到显著差异。
在上颌种植覆盖义齿使用非夹板式附着体时,建议使用磁性附着体以减轻种植体应力。无论附着体类型如何,均不建议仅使用两个种植体,尤其是两个前部种植体。