- 學位論文
馬來膠針於溫熱牙膠擠壓充填法中溫度變化之研究
The investigation of the gutta percha temperature change on vertical compaction of warm gutta percha technique
摘要
三度空間的緻密封填是成功的根管治療的關鍵之一，其主要目的為：減少經由口腔或根尖周圍組織滲透進入根管系統的通道以及將根管清創、修形過程中無法完全移除的感染物質，封閉於根管系統內，由於側方封填法的缺點是容易在根管系統中留下許多間隙。因此溫熱垂直擠壓封填法，以及經過改良的連續波封填法被提出後，漸漸成為主要的封填技術。但是，在此技術操作下馬來膠必須經過提高溫度及反覆加熱，過高的溫度雖會使馬來膠流動性較好卻也會傷害牙周組織，溫度太低則無法達到緻密封填。然而，過去實驗所探討的溫度變化，卻常常因為加熱源的不穩定或是分析儀器的限制，對於根管內溫度的連續性變化一直不明朗。本研究的目的是分析比較四種醫用馬來膠針材料組成、溫度與填壓力量的變化及根管內的熱傳導變化，並且利用口外模型來模擬實際臨床操作步驟；模型為使用上顎前牙修型為一個根尖開口大小為0.4公厘、錐度為6%的根管型狀；使用的加熱器為Elements Obturation Unit，設定在200 ˚C。操作過程使用紅外線熱像儀作分析。掃描式電子顯微鏡及能量散佈分析儀分析發現醫用馬來膠針成分依舊以氧化鋅做為基底，但Protaper Gutta Pacha 組成中含有大量鐵原子，與其他三組差異極大。熱示差分析顯示醫用熱封填專用馬來膠完全軟化溫度在47.06 ˚C ~ 64.61 ˚C度間，而填壓力量則因廠牌及溫度的不同而有差異，Autofit在四種馬來膠中所填壓的力量最小，最容易操作；體外模型模擬封填則發現Schilder所建議封填至根尖5mm~7mm則不足以使根尖溫度上升至馬來膠可操作的溫度，研究顯示封填至離根尖3mm處加熱兩次並於最終加壓10秒可以得到較好的緻密封填。
並列摘要
Traditional warm gutta-percha vertical compaction technique and a modified technique called continuous wave technique are major techniques for warm gutta-percha root canal obturation. However, the gutta-percha temperature rise pattern in these techniques is still unclear. The purpose of this study was to identify the heat transfer on gutta percha. Maxillary central incisor canal was prepared to #40 MAF with stainless files and TF file. The canals were obturated with Gutta-percha by vertical compaction technique and continuous wave technique. The heat instrument Elements Obturation Unit was set at 200 ˚C. All procedure was monitor by the infrared camera. Thermal analysis showed that melting point of the commercial gutta percha between 47.06 ˚C ~64.61˚C 。In vitro show that the temperature at last 3mm was remain at room temperature when down packing to the distance from the apical 5mm; the temperature rose to 48.27˚C , gutta percha molding temperature, when down packing to the apical 4mm. These results demonstrated that 4 mm to the apex may be the proper deepest down packing distance for the vertical compaction of warm GP technique.