Queiroz Thallita P, Aguiar Samuel C, Margonar Rogério, de Souza Faloni Ana P, Gruber Reinhard, Luvizuto Eloá R
Department of Health Sciences, Implantology Post Graduation Course, Dental School, University Center of Araraquara - UNIARA, São Paulo, Brazil.
Laboratory of Oral Cell Biology, School of Dental Medicine, University of Bern, Bern, Switzerland.
Clin Oral Implants Res. 2015 Sep;26(9):1036-42. doi: 10.1111/clr.12394. Epub 2014 Apr 16.
Short implants are increasingly used, but there is doubt about their performance being similar to that of regular implants. The aim of this study was to compare the mechanical stability of short implants vs. regular implants placed in the edentulous posterior mandible.
Twenty-three patients received a total of 48 short implants (5 × 5.5 mm and 5 × 7 mm) and 42 regular implants (4 × 10 mm and 4 × 11.5 mm) in the posterior mandible. Patients who received short implants had <10 mm of bone height measured from the bone crest to the outer wall of the mandibular canal. Resonance frequency analysis (RFA) was performed at time intervals T0 (immediately after implant placement), T1 (after 15 days), T2 (after 30 days), T3 (after 60 days), and T4 (after 90 days).
The survival rate after 90 days was 87.5% for the short implants and 100% for regular implants (P < 0.05). There was no significant difference between the implants in time intervals T1, T2, T3, and T4. In T0, the RFA values of 5 × 5.5 implants were higher than values of 5 × 7 and 4 × 11.5 implants (P < 0.05). A total of six short implants that were placed in four patients were lost (three of 5 × 5.5 mm and three of 5 × 7 mm). Three lost implants started with high ISQ values, which progressively decreased. The other three lost implants started with a slightly lower ISQ value, which rose and then began to fall.
Survival rate of short implants after 90 days was lower than that of regular implants. However, short implants may be considered a reasonable alternative for rehabilitation of severely resorbed mandibles with reduced height, to avoid performing bone reconstruction before implant placement. Patients need to be aware of the reduced survival rate compared with regular implants before implant placement to avoid disappointments.
短种植体的使用日益增多，但人们对其性能是否与常规种植体相似存在疑问。本研究的目的是比较短种植体与放置在下颌后牙区无牙颌的常规种植体的机械稳定性。
23例患者在下颌后牙区共植入48枚短种植体（5×5.5mm和5×7mm）和42枚常规种植体（4×10mm和4×11.5mm）。接受短种植体的患者从牙槽嵴到下颌管外壁测量的骨高度<10mm。在时间间隔T0（种植体植入后立即）、T1（15天后）、T2（30天后）、T3（60天后）和T4（90天后）进行共振频率分析（RFA）。
短种植体90天后的存活率为87.5%，常规种植体为100%（P<0.05）。在时间间隔T1、T2、T3和T4时，种植体之间无显著差异。在T0时，5×5.5种植体的RFA值高于5×7和4×11.5种植体的值（P<0.05）。共有4例患者植入的6枚短种植体丢失（5×5.5mm的3枚和5×7mm的3枚）。3枚丢失的种植体起始ISQ值较高，随后逐渐下降。另外3枚丢失的种植体起始ISQ值略低，先上升然后开始下降。
短种植体90天后的存活率低于常规种植体。然而，短种植体可被视为严重吸收且高度降低的下颌骨修复的合理替代方案，以避免在种植体植入前进行骨重建。患者在种植体植入前需要了解与常规种植体相比存活率较低，以免失望。
