人工植牙在臨床運用上已有相當高的可預測性及長期成功率，然而，在上顎後牙區種植人工牙根其成功率仍低於下顎區植牙，其原因除了齒槽骨骨質在分類上屬於較差的骨質，以及無足夠的骨量對植體提供適當的支撐，上顎後牙區亦有上顎竇(maxillary sinus)的解剖限制。上顎竇提昇術(sinus floor augmentation)藉由竇膜提昇填充移植骨(bone graft)方式增加骨量，提供植體植入後較佳之支撐，在臨床應用上，有許多的手術方式與移植骨種類可供運用，但對於填充移植骨數量並無清楚的了解；本研究之目的是以有限元素的方式，針對上顎竇提昇術對人工植牙的生物力學分析，並針對移植骨數量做量化評估，同時進一步探討植入不同植體長度對周圍骨組織之力學反應，期望找出較經濟、有效的移植骨數量與植體長度，對於臨床運用上顎竇提昇術，有較清楚的生物力學認識，並對臨床醫師在手術上關於選擇補骨量與植體長度提供建議。
　　本研究之初步結果顯示，以上顎竇提昇術增加骨量對於植體提供較佳穩定度，殘餘骨應力值明顯降低；而在無填充移植骨的情況下，植體長度的增加對於降低應力效果貢獻甚低，此外，就本研究模擬情況中，發現移植骨數量之降低骨應力效應大於植體長度，因此在臨床治療上，建議增加移植骨數量會優於植體長度的效果，而移植骨完全填充竇膜下創造出的空間，對於力學反應有正面效果，可有效降低骨應力值；但以臨床角度考量移植骨新生骨重塑時間(愈多的移植骨填充需要更長的新生骨重塑時間)，以本研究之結果建議，在植體周圍填充移植骨，舌側-頰側方向若有3~4㎜厚度即具有明顯降低骨應力值的效果；而在植體長度效應方面，發現較長之植體長度，並沒有表現出預期較明顯之降低骨質應力效果，其原因可能係本研究建構之上顎骨屬於較健康的，以本研究之模擬情況下(齒槽脊至上顎竇底間高度7㎜為固定)，植體長度增加到13㎜後，其骨應力值降低的效果就不明顯。

　　Maxilla often comprised poor bone quality and insufficient bone volume, which provoked a high failure rate of dental implantation. Furthermore, the continuing pneumatization of maxillary sinus throughout life make implantation in this region be a challenging task. The maxillary sinus floor augmentation is one of the common surgery procedures to increase bone volume for implant placement. However, the sinus lifting is performed with various materials and techniques without precise knowledge of the quantity effects of bone grafting. The purpose of this study was to quantifying the biomechanical response of sinus floor augmentation on dental implant. More specifically, to investigate the effects of bone graft quantity and implant lengths on maxilla implantation with finite element analyses.
　　The results of the analyses indicated that sinus floor augmentation could reduce the peak stress on residual alveolar bone with increased bone volume. Observed from the stress distribution on the bone, the high stress was located around the implant and this phenomenon coincided with the location of initial alveolar bone loss at the dental implant. With bone graft, the occlusal load could be redistributed to reduce the peak stress at crestal cortical bone. However, with an averaged (healthy) maxilla modeled in this study, the contribution of bone graft volume has its limit. The bone grafted with 4.5 mm thickness in the mesial-distal direction and, 3 to 4 mm of packing thickness in bucco-lingual direction is sufficient. Furthermore, the additional length of dental implant projected into the maxillary sinus without bone graft surrounding provided insignificant contribution in terms of stress reduction and stability. With sufficient packing thickness, an implant length of 13mm is enough. Based on this study, the most efficient packing thickness is 3mm with 13mm of implant length.

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