固定式矯正裝置改善咬合不正的治療過程中，有時牙齒會發生有不可逆的牙齦萎縮的現象發生。牙齦萎縮可能引起不美觀或者牙根敏感症狀，以牙根覆蓋術式覆蓋暴露牙根是解決上述問題的最佳選擇。羊膜為胎膜的最內層，除了含有許多生長因子，其胞外間質之中含有大量的膠原蛋白基質。因此羊膜適用於組織生長支架材料及傷口敷料，且被證實可以加速傷口癒合及重建受損的器官。本研究之目的為評估羊膜應用於牙根覆蓋之可能性，特別是羊膜對於組織傷口癒合的影響及對牙周組織再生的作用。 本實驗以三隻小獵犬的上下顎第三門齒、上下顎第二、第三、第四小臼齒及上顎第一小臼齒為實驗對象，在實驗牙齒上切除部份牙周組織製造5毫米之骨缺損及牙齦萎縮，一個月後進行牙根覆蓋手術。進行牙根覆蓋手術時，以實驗動物右側上下顎牙齒為實驗組，於牙根覆蓋手術多覆蓋一層羊膜；而左側同名牙齒則為對照組，雖執行牙根覆蓋手術但未加放羊膜。之後，依據實驗組不同，於牙根覆蓋手術之後的第三天、兩星期、一個月、兩個月、六個月，將動物犧牲並進行組織切片觀察。臨床評估包括牙周囊袋深度、牙齦萎縮量及邊緣牙齦發炎程度。組織切片形態分析及量化則包括牙周組織再生情況、牙齦覆蓋高度、上皮高度及厚度等等。 本研究結果發現：羊膜於傷口初期癒合時，具有降低發炎反應、增加牙根覆蓋後傷口區域的血管數量及促進組織癒合之作用，且同時有利於牙齦邊緣的表皮細胞往牙冠部移行生長。因此，組織學形態觀察顯示羊膜應用於牙根覆蓋時，應仍具有促進牙周組織再生的優勢。於牙周組織再生、牙齦覆蓋高度、上皮高度及厚度等量化分析方面，實驗組的牙周組織再生量、牙齦覆蓋量、上皮厚度等組織形態測量較未貼附羊膜的對照組為多，但二組之差異未達統計顯著性。
Gingival recession is the most common mucogingival deformity in adult orthodontic patients. Treatment of gingival recession has been an important therapeutic issue due to increasing cosmetic demand. The exposed roots could be covered by various surgical procedures including connective tissue graft, free gingival grafts, coronally positioned flaps, and the use of barrier membranes. The amniotic membrane, the innermost layer of the fetal membrane, contains growth factors and large amount of collagen matrix. Therefore, amniotic membrane has been successfully used as a scaffold for cell growth and as a physiological wound dressing. The aim of this study was to assess the effect of applying de-epithelialized amniotic membrane in root coverage surgery to promote tissue regeneration. In a split-mouth design, the maxillary and mandibular third incisors, canines, second premolars, third premolars, and maxillary first premolars of 3 adult mongrel dogs were used. The buccal osseous dehiscence and gingival recession were surgically created 1 month prior to root coverage surgery, and refined immediately before the surgery. The exposed root surfaces were covered with de-epithelialized human amniotic membrane, and followed by the coronally positioned flap (experimental group). On the contralateral side, the coronally positioned flap was conducted without coverage of amniotic membrane (control group). The clinical parameters assessed during the experimental period included the probing depth and the amount of gingival recession (n =4~5). The observation time points were the 3 days, 2 weeks, 1 months, 2 months, and 6 months after root coverage. After the animals were sacrificed, the specimens of dento-periodontal complex were processed for paraffin sections and stained with haematoxylin-eosin. Histomorphometric evaluations were conducted by analyzing the parameters including the amount of new cementum formation, new bone formation, connective tissue regeneration, root coverage, epithelium thickness and height. Our results revealed that the amniotic membrane may inhibit tissue inflammation and promote rapid epithelialization at the initial healing of the gingival wound. The histomorphometric analysis showed that the periodontal tissue regeneration and root coverage in the experimental group were better than those in the control group. However, the group differences were not statistically significant. Further studies of higher sample size are needed to clearly assess the beneficial effect of applying amniotic membrane in the periodontal surgical procedures for root coverage.