臺灣博碩士論文加值系統

成功的根管治療，必須依賴充分的清創工作。一些研究發現機械清創的同時會有殘屑的堆積，並且有塗抹層的形成，Gutterrez等人建議移除此塗抹層，以利根管的充填後得到一個良好的封閉效果12。傳統的沖洗液如次氯酸鈉並不能有效的移除塗抹層，加上近年來雷射的蓬勃發展，便有研究者嘗試用於根管治療中，只可惜這方面的研究仍然有限。因此本研究的目的在於分析釹雅克雷射對根管壁牙本質的作用情形以及去除塗抹層的能力。
實驗採用70顆單根管的牙齒，隨機分成14組，每組5顆牙齒。對照組和實驗組：用K型的銼針清創，號數從#15-#40，退展到#55，過程中每換一號用1c.c.蒸餾水沖洗。處理過後的牙齒自牙釉質與牙骨質交接處橫切，牙冠捨棄不用，接著將牙根剖成兩半，固定在標本臺上。對照組不照雷射，實驗組分A-H組，模仿臨床銼修的動作。沿牙齒長軸朝牙冠三分之一的部分平行移動，每次3秒，每個根管二十次，共一分鐘。實驗組I-M組，則將時間延長至兩分鐘，將處理過後的標本以立體顯微鏡和電子顯微鏡記錄。
結果發現，在對照組方面，不見牙本質小管的開口，根管的表面被不規則的塗抹層所覆蓋。而在實驗組方面，經由雷射照射後不僅塗抹層消失並且造成表面牙本質小管的露出和表面的熔融。所有的能量組合中，150mJ/pulse×10pps照射時間一分鐘，不僅去除塗抹層並且會造成一層均勻的熔融層。
依據實驗結果得知，適當的能量作用下，釹雅克雷射對於塗抹層具有良好的清除效果，若合併傳統器械用於臨床時，應能增加根管治療的成功率。若將雷射應用於根管治療中，應注意以下幾點：(1)儘量保持根管的乾燥，並且時常注意雷射光纖的完整，(2)為了增加雷射的作用效果，最好選擇高脈衝能量如150mJ和低照射頻率如10pps為佳。

The success of endodontic treatment depended on the root canal system being thoroughly cleaned and disinfected. Studies had shown that endodontic instruments produce organic and mineral debris called the smear layer. Gutterrez et al. have postulated that the removal of the smear layer facilitates the penetration of the plastic base root canal cement materials to obtain a more hermetic seal when the root canal is obturated12. Nd:YAG laser had been shown to have sealing effect on dentinal tubules and removing effect on smear layer. However, limited information has been reported about the factors affecting the morphologic changes of canal wall dentin following Nd:YAG laser irradiation. The purpose of this study was to evaluate the efficacy of Nd:YAG laser irradiation in removing debris and smear layer from prepared root canal walls.
Seventy human extracted teeth with a single-canal root canal were used for study. The teeth were opened and prepared from #15 to #55 K-type file. Copious irrigation with distill water was performed between each file. After preparation of the teeth, the crowns were removed at the CEJ, and were bisected. The specimens were divided into fourteen groups. The control specimens that were not lased, and the teeth of group A to group M were irradiated by Nd:YAG laser at different powers. The specimens were examined under Stereoscope and scanning electron microscope.
In the control group, the canals were covered by an amorphous smear layer on the surface of the canal wall. The root canal walls irradiated by Nd:YAG laser were free of debris, with an evaporated smear layer and open dentinal tubules.These results show Nd;YAG laser is effective in removing debris and smear layer from root canal walls. The energy combination ( 150mJ/pulse, 10pps, 1min ) has the better effects on melting the root canal wall surface and removing the smear layer.
It is concluded that a proper irradiation condition would enhance the removed area of smear layer, result in melting and resolidification of the dentin, and seal the orifices of dentinal tubules. When Nd:YAG laser is used in endodontics, the followings are our recommendations: (1)Keep the canal wall as dry as possible before lasing and always check the fiberoptic tip before lasing, (2)In order to increase the lasing effects under the same energy output, it is better to adopt high power and short irradiation time.

中文摘要………………………………………………………I
英文摘要……………………………………………………III
目錄……………………………………………………………V
第一章 緒言……………………………………………1
第二章 文獻回顧………………………………………3
2-1 塗抹層的性質…………………………………3
2-2 雷射機器的原理………………………………5
2-3 雷射的醫療原理………………………………6
2-4 牙科方面雷射的應用…………………………7
2-5 雷射在根管治療方面的應用…………………9
2-6 動機和目的………………………………….11
第三章 材料和方法………………………………….12
3-1 雷射機器…………………………………….12
3-2 條件設定…………………………………….12
3-3 牙齒的保存………………………………….13
3-4 牙根的選擇………………………………….13
3-5 實驗方法…………………………………….14
3-6 實驗結果的記錄…………………………….18
第四章 結果………………………………………….21
4-1 光學影像的記錄…………………………….21
4-2 電子顯微鏡的觀察………………………….22
4-3 實驗各組去除塗抹層的定量分析………….29
第五章 討論………………………………………….31
5-1 實驗設計的探討…………………………….31
5-2 未照雷射組別的探討……………………….35
5-3 不同能量的Nd:YAG雷射對根管壁作用機制
的探討……………………………………….36
5-4 雷射照射後的牙本質形態變化…………….38
第六章 結論………………………………………….40
附圖………………………………………………………….42
附表………………………………………………………….64
參考文獻…………………………………………………….67

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