不同之超音波設定與機頭尖端設計對根尖窩洞修形的影響

Effects of Ultrasonic Retrotip Design and Power Setting Upon Retrocavity Preparation

楊正媺(Cheng-Mei Yang) ； 陳獻仁(Hsien-Jen Chen)

《中華牙醫學雜誌（中文版）》 1卷2期 (2005/06) Pp. 123-128

https://doi.org/10.7106/CJD.200506.0123

摘要

在根尖手術過程中，藉由超音波搭配特殊設計的機頭尖端，可使得根尖根管的逆向窩洞修形步驟，能在較短的時間與破壞較少根尖齒質的情況下完成。但有研究顯示使用超音波器械會比使用鑽頭者，產生較多的裂隙，而所驅動的超音波強度越大，裂隙的產生就更多。本研究之目的即觀察塗覆鑽石顆粒的超音波機頭尖端與傳統不銹鋼者相較，是否眞能減少根尖窩洞修形後裂隙的產生，並檢視在不同超音波強度下，對裂隙產生的影響，以便對術後的預後能有更準確的評估。本實驗將40顆單牙根的人類前牙及小臼齒在以旋轉式機械做好根管修形後，以熱塑馬來膠完成根管充塡。將根尖切除後，以傳統不銹鋼或是塗覆有鑽石顆粒的機頭尖端，分別在中高或低強度超音波驅動下，進行根尖窩洞修形，並在顯微鏡下觀察裂隙的產生與否，以及窩洞邊緣破壞情形。研究結果顯示，不論是使用塗覆鑽石顆粒或傳統不銹鋼的超音波機頭尖端，或是使用中高度，都很少造成裂隙或窩洞邊緣破壞，且各組所產生的裂隙及窩洞邊緣的完整性，都沒有統計學上的明顯差異。

關鍵字

超音波機頭尖端 ； 根尖窩洞修形 ； 裂隙 ； 邊緣缺損

並列摘要

During endodontic treatment, apical surgery can be performed in a shorter time with less tissue destruction since the introduction of ultrasonic instruments. But studies have shown that ultrasonic root-end preparation produces more cracks compared to the bur method. Also, more cracks are found with higher ultrasonic power settings than with the lower power settings. New diamond-coated ultrasonic tips are believed to reduce microcrack formation for better cutting efficiencies. The purpose of this study was to compare root-end preparations made with conventional and diamond-coated ultrasonic tips under different power settings for the incidence of microcracks. Forty freshly extracted human anterior and premolar teeth were selected for this experiment. After instrumentation, obturation, and root-end resection, a retrograde cavity was prepared with conventional or diamond-coated ultrasonic tips under low or middle-high power settings. The appearance of cracks and the marginal integrity of those retrograde cavities were evaluated under a stereomicroscope. The results revealed no statistically significant differences among ultrasonic retrotip designs or power settings.

並列關鍵字

ultrasonic tip ； root-end preparation ； microcrack ； marginal chipping