Lecturer, School of Dentistry, State University of Maringá-UEM, Maringá, Brazil.
J Prosthet Dent. 2013 Nov;110(5):383-8. doi: 10.1016/j.prosdent.2013.06.007. Epub 2013 Sep 24.
The mechanical behavior of internal taper implant abutment designs needs to be evaluated.
The purpose of this study was to evaluate the effect of simulated mechanical loading on the removal torque of 1-piece and 2-piece abutments connected to internal taper oral implants.
Forty-eight internally notched taper implants were divided into 2 groups of 24. Group OP received solid (1-piece) abutments; group TP received esthetic (2-piece) abutments. Each group was further subdivided into subgroups C (control) without mechanical loading and T (test) with mechanical loading. In groups OPC and TPC, the abutments were placed and removed and the removal torque values (RTVs) registered. In groups OPT and TPT, abutments were placed, mechanically loaded (500 000 cycles), removed, and the RTVs registered. Groups TPC and TPT were further tested for the traction force necessary to dislodge the abutment from the implant. For data analysis, the Student t test (for RTVs) and the Mann-Whitney U test (for TFVs) (α=.05) were performed.
All abutments tested presented torque loss with RTVs lower than the placement torque. A statistically significant difference (P=.002) was found between groups OPC (81.6% of placement torque) and OPT mean RTVs results (85.0% of placement torque), while no statistical differences (P=.362) were found between groups TPC (63.7% of placement torque) and TPT (59.1% of placement torque). The traction force values necessary to dislodge the abutment from the implant, however, were significantly higher (P<.001) for group TPT than for group TPC.
Cold welding did not occur in any of the abutment specimens tested. Even after the mechanical loading, esthetic abutments presented similar RTVs. The traction force necessary to remove esthetic abutments from inside the implants presented a 2-fold increase after mechanical loading.
需要评估内部锥度种植体基台设计的机械性能。
本研究的目的是评估模拟机械负载对连接到内部锥度口腔种植体的 1 件式和 2 件式基台的去除扭矩的影响。
将 48 个内部有槽的锥度种植体分为 2 组，每组 24 个。OP 组接受实心（1 件式）基台；TP 组接受美学（2 件式）基台。每组进一步分为 C（对照）组和 T（测试）组，无机械加载。在 OPC 和 TPC 组中，放置和移除基台，并记录去除扭矩值（RTV）。在 OPT 和 TPT 组中，放置基台，进行机械加载（50 万次循环），移除，并记录 RTV。将 TPC 和 TPT 组进一步测试以移除基台所需的牵引力。对于数据分析，使用学生 t 检验（用于 RTV）和曼-惠特尼 U 检验（用于 TFV）（α=.05）。
所有测试的基台均出现扭矩损失，RTV 低于放置扭矩。OPC 组（放置扭矩的 81.6%）和 OPT 组的平均 RTV 结果（放置扭矩的 85.0%）之间存在统计学显著差异（P=.002），而 TPC 组（放置扭矩的 63.7%）和 TPT 组（放置扭矩的 59.1%）之间无统计学差异（P=.362）。然而，从种植体上移除基台所需的牵引力值在 TPT 组显著高于 TPC 组（P<.001）。
在测试的任何基台样本中都没有发生冷焊接。即使在机械加载后，美学基台也表现出相似的 RTV。从种植体内移除美学基台所需的牵引力在机械加载后增加了 2 倍。
