Objective To observe the difference between the self-repair of gingival tissue in retained dental root and the soft tissue healing after tooth extraction in the area of the anterior teeth of the canines. Methods Residual roots models were made in the three dogs' maxillary anterior teeth areas ( right maxillary lateral incisor and left max-illary central incisor) . Moreover, the three dogs' left mandibular lateral incisors were extracted. Then, the degrees of growth under the two different gingiva healing conditions were observed in the 1st, 3rd, 4th and 5th week after surgery. Besides, the gingival hyperplasia tissue in the left maxillary central incisor and soft tissue hyperplasia in the left mandibular lateral incisor tooth were obtained at 3rd, 4th and 5th week after surgery respectively for histo-logical observation. Results We found that the new soft tissue around residual root was overgrown on cross-section in the 4th week after surgery by the unaided eye, and the texture and color of the new soft tissue in the 5th week af-ter surgery was similar to that of the normal gingiva. Meanwhile, soft tissue which was harder in texture and lighter in color compared with the normal gingiva was fully covered on wound 3 weeks after tooth extractions. Histological observation found that the new born soft tissue hyperplasia around the residual roots mainly was squamous cell hy-perplasia, and the inflammatory cells infiltration was not obvious. On the contrary, histological observation on the soft tissue around the tooth extraction wound demonstrated obvious inflammatory cells infiltration and mild squamous cell hyperplasia. Conclusion The hyperplasia and healing of gingival tissue in reserving residual roots are slower than those in soft tissue after extracting a tooth, but it is more similar to the normal gingiva.%目的：观察残根保留情况下牙龈软组织的自我修复与拔牙后软组织愈合在犬前牙区软组织愈合中的不同。方法在A、B、C3只犬的上颌前牙区(右上颌侧切牙，左上颌中切牙)制造残根模型，将牙冠磨至龈缘下，勿损伤牙龈(将此设为残根组)；拔除3只犬的左下颌侧切牙(将此设为拔牙组)；术后第1、3、4、5周观察两种不同牙龈愈合生长的情况，并在术后第3、4、5周按照A、B、C顺序取左上颌中切牙牙龈增生组织、左下颌侧切牙拔牙创增生软组织进行组织学观察。结果术后第4周时肉眼观察到残根周围新生软组织基本长满断面，第5周时新生软组织的质地及颜色与正常牙龈基本一致；拔牙术后第3周时软组织已基本长满创面，但肉眼观察其颜色较浅，质地较硬；组织学观察残根周围新增生的软组织以增生的鳞状上皮为主，炎细胞浸润不明显；而拔牙创周围软组织则表现为明显的炎细胞浸润，鳞状上皮轻度增生。结论采用保留残根后新增生的牙龈软组织较拔牙后软组织愈合慢，但是更接近于正常牙龈组织。
展开▼
