J Prosthet Dent. 2012 Jun;107(6):358-65. doi: 10.1016/S0022-3913(12)60090-0.
There is little information as to how the number and distribution of implants affect the amount of load transmitted to the palate in implant-retained maxillary overdentures.
The purpose of this study was to evaluate the effect of the number and distribution of dental implants on the load transmitted to the palate.
Eight implant analogues were placed in a replica of an average sized edentulous maxilla corresponding to the position of canines, first and second premolars, and first molars. The anteroposterior distance between the centers of implants in each quadrant was 8 mm. Fifteen denture bases were fabricated to fit the edentulous maxilla analogue. The denture bases were attached to the oral analogue using 6 different configurations of attachments (6 groups): Either no Locator attachments were used (control group), or the 2 most anterior attachments were attached, or 4 implants were engaged with a distance of 8, 16, or 24 mm between the centers of implants on left and right side, and finally, when all 8 attachments were activated. A force-measuring sensor was used to measure the force transmitted to the palate when a static force of 245 N was applied on the occlusal rims of the denture bases. Data (Newtons) were analyzed using 1-way ANOVA and Tukey's HSD test α=.05).
The mean (SD) amount of force measured on the palate when the overdentures were supported by 4 Locator attachments; [49.84 (26.52) at 8 mm spacing], [24.42 (15.05) at 16 mm spacing], [35.66 (22.94) at 24 mm spacing] was significantly lower than when no attachments [90.98 (20.20), control], or when 2 Locator attachments were used [76.07 (27.63)] (P<.001). When the overdentures were supported by 8 Locator attachments, the force measured on the palate [20.67(16.06) N] was significantly lower than that for the control group (P<.001), overdentures supported by 2 Locator attachments (P<.001), and overdentures supported by 4 Locator attachments when the distance between the anterior and posterior implants was 8 mm P=.006).
The distribution of implants had a significant effect on the force measured on the palate of the oral analogue in overdentures retained by Locator attachments. When the distance between the 4 implants was 16 or more mm, the load was not significantly lower than the 8 implant design, suggesting that the palate of a 4 implant-retained overdenture with a distance of 16 mm or more, does not contribute significantly to the load transfer to underlying hard palate in the in vitro analogue evaluated.
关于种植体的数量和分布如何影响上颌覆盖义齿传递到腭部的负荷量，相关信息较少。
本研究旨在评估种植体的数量和分布对传递到腭部的负荷量的影响。
将 8 个种植体模拟体放置在对应于犬齿、第一前磨牙和第一磨牙位置的无牙上颌模型中。每个象限中种植体中心之间的前后距离为 8mm。制作了 15 个义齿基托以适应无牙上颌模型。使用 6 种不同附着体配置（6 组）将义齿基托连接到口腔模型上：不使用Locator 附着体（对照组），或连接前 2 个附着体，或连接 4 个种植体，左侧和右侧种植体中心之间的距离为 8、16 或 24mm，最后，当所有 8 个附着体都激活时。当在义齿基托的牙合面边缘施加 245N 的静态力时，使用测力传感器测量传递到腭部的力。使用单向方差分析和 Tukey 的 HSD 检验（α=.05）对数据（牛顿）进行分析。
当 4 个 Locator 附着体支撑覆盖义齿时，测量到的腭部受力平均值（标准差）为[49.84（26.52），8mm 间距]、[24.42（15.05），16mm 间距]、[35.66（22.94），24mm 间距]，明显低于无附着体[90.98（20.20），对照组]或使用 2 个 Locator 附着体[76.07（27.63）]（P<.001）。当 8 个 Locator 附着体支撑覆盖义齿时，测量到的腭部受力[20.67（16.06）N]明显低于对照组（P<.001），低于使用 2 个 Locator 附着体（P<.001），低于使用 4 个 Locator 附着体时前、后种植体之间的距离为 8mm（P=.006）。
附着体的分布对上颌覆盖义齿中腭部受力有显著影响。当 4 个种植体之间的距离为 16mm 或更大时，负荷并不明显低于 8 个种植体设计，这表明在评估的体外模型中，距离为 16mm 或更大的 4 个种植体保留的覆盖义齿的腭部对下覆硬腭的负荷传递没有显著贡献。
