Bystedt Hans, Rasmusson Lars
Department of Oral and Maxillofacial Surgery, Visby County Hospital, Visby, Sweden.
Clin Implant Dent Relat Res. 2009 Jun;11(2):101-5. doi: 10.1111/j.1708-8208.2008.00100.x. Epub 2008 Jul 24.
Resorption of grafting material may lead to unpredictable long-term results when rehabilitating the resorbed posterior maxilla. Nonresorbable, osteoconductive bone substitutes may therefore be an advantage over autogenous bone grafts.
The aim of the present pilot study was to test titanium granules as bone substitute in patients planned for augmentation of the sinus floor prior to or in conjunction with placement of dental implants.
Sixteen patients with uni- or bilateral edentulism and need for augmentation of the sinus floor were included in the study. Residual bone height was 2 to 5 mm. Grafting and installation of the dental implants (18 fixtures) was carried out in the same session if primary stability of the implants could be achieved (12 patients). A staged protocol with implant placement 3 to 7 months after the augmentation procedure was used when primary implant stability was impossible to achieve (four patients). In all, 23 TiOblast (Astra Tech AB, Mölndal, Sweden) implants were installed.
The patients have been followed 12 to 36 months after prosthetic loading. Three implants were found mobile and were removed (13.0%). Two of these were in patients where grafting and implant installation were carried out in separate procedures. The implants were found mobile at abutment connection and were removed. One patient in the single-stage group had a postoperative sinus infection, which was successfully treated with antibiotics. However, one out of two implants in this patient was found mobile and was removed after 1 year in function.
In the present study, titanium granules seem to function as augmentation material in the sinus floor. It is, however, not clear if the material can be safely used for two-stage procedures. Further investigations with longer healing time before implant installation are required. Also, the possible risk of granule displacement during preparation of the fixture site should be further investigated. Additionally, biopsies from patients are requested to confirm any bone ingrowth between the granules.
在修复吸收后的上颌后牙区时，移植材料的吸收可能导致不可预测的长期效果。因此，不可吸收的骨传导性骨替代材料可能比自体骨移植更具优势。
本初步研究的目的是测试钛颗粒作为骨替代材料，用于计划在种植体植入前或同时进行上颌窦底提升的患者。
16例单侧或双侧无牙且需要进行上颌窦底提升的患者纳入本研究。剩余骨高度为2至5毫米。如果种植体能获得初期稳定性（12例患者），则在同一次手术中进行移植和种植体植入（18颗种植体）。当无法获得种植体初期稳定性时（4例患者），采用在提升手术后3至7个月植入种植体的分期方案。总共植入了23颗TiOblast（瑞典莫恩达尔阿斯特拉科技公司）种植体。
患者在修复体加载后随访了12至36个月。发现3颗种植体松动并被取出（13.0%）。其中2颗位于移植和种植体植入分阶段进行的患者。这些种植体在基台连接时发现松动并被取出。单阶段组的1例患者术后发生上颌窦感染，经抗生素治疗成功。然而，该患者的2颗种植体中有1颗在使用1年后发现松动并被取出。
在本研究中，钛颗粒似乎可作为上颌窦底的提升材料。然而，尚不清楚该材料是否可安全用于两阶段手术。需要在种植体植入前进行更长愈合时间的进一步研究。此外，还应进一步研究在种植体植入部位制备过程中颗粒移位的可能风险。另外，需要对患者进行活检以确认颗粒之间是否有骨长入。
