MTA和DFC應用於乳牙冠髓切除術之長期臨床試驗結果與預後探討

Abstract

本研究為前瞻性隨機分派臨床長期試驗，目的為探討灰色三氧礦化聚合物(Gray Mineral Trioxide Aggregate，GMTA)是否可取代傳統的20% 稀釋甲酚甲醛(20% Diluted formocresal，DFC)成為乳臼齒冠髓切除術的理想材料，並分析兩種材料治療失敗的狀況。本研究招募自2009年12月至2013年6月30日止，於台灣大學附設醫院牙科部兒童牙科求診的健康正常孩童，有效受試者有103人(年齡介於2.8歲至9.9歲)，共249顆乳臼齒(DFC組有122顆，GMTA組有127顆)，三年內的回診率皆大於七成以上。在GMTA組，術後三年內的臨床治療成功率為100%，而DFC組有牙齒表現發生膿腫而拔除，臨床治療成功率為96~100%，兩個組別在臨床成功率並未有統計上的顯著差異。在放射線學成功率方面，GMTA組在3年內的成功率均大於九成以上（94%-99%），而DFC組的成功率則從第1年回診的88%，逐年降低至第3年回診追蹤的67%，在所有追蹤期間內，兩個組別在放射線學成功率有統計上的顯著差異(p≤0.006)。其中兩組材料在發生牙本質屏障、根管鈣化及牙根內吸收變化的分布有統計上的顯著差異。在牙齒接受治療至脫落或被拔除的存活分析，DFC組的存活曲線下降的情況比GMTA組要明顯，檢定統計值接近顯著差異(p=0.054)。而在牙齒接受治療至發生放射線學失敗的存活分析，DFC組有較多牙齒發生放射線學失敗，DFC組的存活率明顯低於GMTA組(p<0.001)。而在組織學分析結果，GMTA組可以觀察到牙本質屏障生成、根管鈣化及完整的造牙本質細胞層，而DFC組觀察到牙根內吸收造成的陷窩、發炎細胞浸潤、組織和材料接觸的表面有異物反應。綜合本研究結果，在臨床發現、放射線學檢查結果以及組織學分析結果，GMTA療效明顯優於DFC，因此GMTA應具潛力取代DFC作為乳牙冠髓切除術的治療材料。

The purpose of this study is to establish a long-term prospective clinical randomized controlled trial (CRT) for assessing the clinical, radiographic, and histological outcomes between gray mineral trioxide aggregate (GMTA) and dilute 20% formocresol (DFC) in pulpotomized human primary molars. To assess this goal, 249 primary molars from 2.8 to 9.9 year-old patients of Department of Pediatric Dentistry of National Taiwan University Hospital were randomly assigned to GMTA group or DFC group. The recall rates within 3-year follow-up period were over 70%. Clinical success was 100% in GMTA group and 96~100% in DFC group because some teeth were exacted due to abscess formation. There is no significant difference in the clinical success rate between GMTA and DFC groups. The radiographic success rate of GMTA group (94% - 99%) were significant higher than that of DFC group (1-year: 86%, 3-year: 67%) at all follow-up periods (p≤0.006). More teeth with dentinal bridge were found in the GMTA group than in the DFC group at all follow-up periods. More teeth with pulp canal obliteration were observed in the DFC group than in the GMTA group within 24-month follow-up. Teeth with internal root resoprtion were only found in DFC. Survival analysis demonstrated that teeth treated with DFC were less likely to survive than teeth treated with GMTA (p=0.054) and DFC treated teeth presented lower survival rate than the GMTA treated teeth in radiographic evaluation. In addition, GMTA demonstrated dentin bridge formation, obliteration of the pulp canal, and regeneration of odontoblasts beneath GMTA histologically. In DFC group, the findings of Howship’s lacunae due to internal root resorption, foreign body reaction to filling material, and infiltration of inflammatory cells were observed. Based on the results of this study, GMTA appears to be a better pulpotomy agent than DFC in primary dentition.