比較不同錐度的鎳-鈦旋轉器械修形對根管清潔率之影響

Root Canal Cleanliness After Preparation with Different Tapers of Ni-Ti Rotary Instruments

林君姿(Chun-Tzu Lin)

指導教授 ： 洪純正

高雄醫學大學/口腔醫學院/牙醫學研究所/碩士(2004年)

摘要

根管治療的目的，在於達成根管系統的清潔與修形，並將修形過後之根管系統作良好的充填與封閉。因此，如何同時達到良好的清潔與成功的修形，一直是根管治療醫師所關心的議題。本研究之目的在於探討相同號數，不同錐度之鎳-鈦旋轉器械在根管修形上，對於其管壁清潔率在冠部、中部、及根尖三部分之比較是否具顯著差異性，以期找出最適當的錐度，達到最佳效率的根管修形與清潔。
本實驗包括四個實驗組，每組各有20個根管，利用GT 鎳-鈦旋轉根管銼（System GT® Rotary Files）配合冠端向下法（crown - down technique）加以修形。A組之最終修形號數為30/0.04，B組修形至30/0.06，C組修形至30/0.08，而D組則修形至30/0.10。在實驗過程中並配合5.25 %之次氯酸鈉溶液及17 %之EDTA溶液作沖洗。之後將牙根縱劈，並利用掃瞄式電子顯微鏡觀察縱劈後牙根根管壁之冠部、中部及根尖部，在200倍下觀察其殘屑含量，在1000倍下觀察其塗抹層含量，並加以評分。將結果使用統計軟體加以分析。
結果顯示，若以相同錐度作修形，在根尖部之殘屑及塗抹層殘留都是三個部位中最多者。而各組之間不同錐度的比較方面，殘屑分數在A組（0.04錐度）分數最高，並在根尖部與C組（0.08錐度）及D組（0.10錐度）皆具顯著差異性；塗抹層分數亦是0.04錐度之A組最高，並在根尖部與其他各組皆具顯著差異性。而分析之結果亦顯示根管位置及修形錐度都是殘屑及塗抹層殘留之顯著影響因素，其中根管位置則為較顯著之影響因子。
由以上結果可得到結論：不論使用何種修形錐度，根尖部之清潔率皆為整個根管之中最差者。若增加器械修形的錐度，的確可提高清潔率。而使用鎳-鈦旋轉器械將根管修形至0.06錐度，於根尖部可得到相較於0.04錐度較好的結果，但若將錐度增加至0.08，其成效更為顯著。

關鍵字

鎳-鈦旋轉器械 ； 根管清潔率 ； 塗抹層 ； 錐度 ； 殘屑

並列摘要

The success of root canal therapy is related with optimal root canal shaping and cleanliness. How to improve the quality of cleaning and shaping at the same time was interested by the dentists. The aim of this study was (1) to investigate the root canal cleanliness of the coronal, middle and apical levels after preparation with the same apical stop and the different tapering Ni-Ti rotary instruments, (2) to find the most appropriate taper of root canal preparation, then to achieve the best quality of root canal cleaning and shaping.
A total of 40 roots with 80 canals were divided into four groups. System GT® Rotary Files were used to prepare the root canals with crown – down technique. The four different canal groups were used the same apical stop size of 30, and shaped with Ni-Ti alloys in tapers of 0.04 (group A), 0.06 (group B), 0.08 (group C), 0.10 (group D), respectively. The 5.25% NaOCl and 17% EDTA were used to enhance the cleanliness. After the roots were split longitudinally, the scanning electron microscope (SEM) study was to compare the cleanliness of the root canal walls at low (x 200) and high (x 1000) magnifications at the coronal, middle and apical levels to calculate the amounts of debris and smear layer. One-way ANOVA was used to analyze the differences in the amounts of debris and smear layer among four groups.
The highest debris and smear layer were found in the apical third. The highest debris scores were recorded in group A, and a significant difference were between group C, group D and group A in the apical thirds of the canals. The highest smear layer scores were also found in group A, and the significant differences were found in the apical thirds compared to group B, C and D. The multiple linear regression analysis showed that the canal position change from coronal to apical and the decrease rate of taper of rotary files were both significant risk factors for debris and smear layer scores. However, the effect of the position of root canals was more significantly.
In summary, the root canal cleanliness of the apical third was the worst than the others. The cleaning efficiency could be improved by increasing the rate of taper to shape the root canals. We suggested that the root canal cleanliness with taper 0.06 mm mm-1 was minimal requirement for Ni-Ti rotary instruments to prepare the root canals.

並列關鍵字

smear layer ； rate of taper ； debris ； Ni-Ti rotary instruments ； canal cleanliness

參考文獻

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