Clinical comparison of short and conventional implants placed in the posterior region of the mandible. A pilot study

Abstract Objective To evaluate and correlate the values of radiographic bone density, peri-implant bone height and resonance frequency analysis (RFA) of short or conventional implants placed in the posterior region of the mandible after installing a prosthesis. Material and method Eleven patients were selected for this prospective parallel pilot study. The prostheses were supported by two types of implants: short implants (n = 18) (5.0 x 5.5 mm and 5.0 x 7.0 mm) and conventional implants (n = 23) (4.0 x10 mm and 4.0 x 11.5 mm). The implants were evaluated by RFA, by measuring the bone height, and peri-implant bone density. The implants were evaluated at the periods T0 (immediately after installation of the prosthesis), T1 (after 90 days), and T2 (after 180 days). Result There were no statistically significant differences between groups with respect to radiographic bone density (152.50 ± 15.39 vs. 157.60 ± 28.46, for conventional and short implants, respectively at T2), stability of the implants (Conventional implants: 66.76 ± 10.39 at T0, and 61.85 ± 8.38 at T2 vs. Short implants: 57.50 ± 12.17 at T0, and 61.53 ± 7.39 at T2) and peri-implant bone loss (0.03 mm vs.-0.17 mm, for conventional and short implants, respectively at T2). Additionally, a significant correlation between the evaluated parameters was not detected. Conclusion The short and conventional implants presented similar stability, bone level and density after the activation of occlusion loading.

摘要 研究目的：本研究旨在评估并关联下颌后区植入的短种植体与常规种植体在修复体戴入后的放射学骨密度、种植体周围骨高度以及共振频率分析（resonance frequency analysis, RFA）的检测数值，并分析各指标间的相关性。
材料与方法：本前瞻性平行对照预试验共纳入11例受试者。修复体由两类种植体支持：短种植体（n=18，规格为5.0×5.5 mm及5.0×7.0 mm）与常规种植体（n=23，规格为4.0×10 mm及4.0×11.5 mm）。分别采用共振频率分析、骨高度测量及种植体周围骨密度检测三种方式对种植体进行评估，评估时间点设置为T0（修复体戴入即刻）、T1（术后90天）与T2（术后180天）。
结果：两组在放射学骨密度指标上无统计学显著性差异（T2时点，常规种植体组为152.50±15.39，短种植体组为157.60±28.46）；种植体稳定性方面，常规种植体组T0时为66.76±10.39，T2时为61.85±8.38，短种植体组T0时为57.50±12.17，T2时为61.53±7.39，两组间亦无统计学差异；种植体周围骨丢失量方面，T2时点常规种植体组为0.03 mm，短种植体组为-0.17 mm，同样无统计学显著性差异。此外，未检测到各评估参数间存在显著相关性。
结论：咬合负载激活后，短种植体与常规种植体在稳定性、骨水平及骨密度方面均表现出相似的临床效果。