生物分解性材料聚左乳酸對於牙周組織的非阻隔性導引作用的可能性研究

The possibility of the biodegradable PLLA in non-barrier type conductive periodontal tissue repopulation

周承澤(Cherng-Tzeh Chou)

指導教授 ： 李勝揚

臺北醫學大學/口腔學院/牙醫學系碩博士班/碩士(2004年)

摘要

藉由測試牙周組織細胞生長於聚左乳酸及鈦金屬骨釘表面的可能性，瞭解此材料對於牙周組織的生物活性，以及作為牙周組織細胞附著再生介面形成新組織再建模式的可行性，以期發展出符合組織工程理論的新用法。選用九隻體重約三公斤的成年紐西蘭白兔，分成三組，每一組兔子三隻。於下顎每側各植入壹枝聚左乳酸可吸收骨釘及鈦金屬骨釘，骨釘直接打穿牙根或與牙根周圍牙周組織直接觸為，以聚左乳酸可吸收骨釘實驗組，陽極氧化鈦金屬骨釘作為對照組。使用8 mm長x 2 mm直徑的聚左乳酸骨釘十八枝，及6 mm長x1.3mm直徑的陽極氧化鈦金屬骨釘十八枝。依據實驗不同犧牲時間四、八、十二週分為三組，組織切片以光學顯微鏡觀察比較組織生長情形。骨釘並以掃瞄式電子顯微鏡做表面觀察做比較，以期找出材料及表面粗糙度不同可能產生的影響。鈦骨釘表面經陽極氧化處理，呈現均勻細微孔性。聚左乳酸可吸收骨釘則依螺紋凸凹部位不同，而呈現不同的特性及細微裂紋。 在組織觀察的樣本中，於四週時即可觀察到牙周組織已分布在陽極氧化鈦與聚左乳酸骨釘的表面，其纖維走向受到螺紋外形與表面粗糙度不同而有所不同。聚左乳酸釘的凸紋處因為較平滑，牙周纖維走向會較平行於表面；鈦釘與聚左乳酸釘的凹紋處，牙周纖維走向則聚及集於最凹處。隨著時間增加，八週及十二週的骨釘周圍與骨直接接觸比例均有明顯增加，尤其是聚左乳酸骨釘。 本實驗驗證牙周組織細胞可以附著再生於陽極氧化鈦金屬與聚左乳骨釘表面並形成不同於非功能性平行排列新組織再建模式的可行性，未來可以依據此模式，影響細胞的外形及分布行為，不必全然受限制於過去採用組織隔離模式，從而發展出直接引導組織再生的新模式，引導新臨床材料的開發使用。

關鍵字

牙周組織 ； 組織導引再生 ； 組織隔膜 ； 聚乳酸 ； 鈦

並列摘要

By testing the possibility of growing periodontal ligament cells on the poly L-lactic acid and anionized titanium bone screw, which can help us learn about the biocompatibility of tested biomaterials. If we can use these biomaterial as medias for PDL cell repopulation and forming new attachment, perhaps we can follow our knowledge about tissue engineering and develop a new way to use these biomaterial. Nine New Zealand white rabbits ,average three kilogram, were divided into three groups. They were randomly assigned by 4,8and 12 weeks experiment period. One 8mm x 2mmPLLA and one 6mm x 1.3mm anionized titanium screw were placed on each side of lower jaw of each rabbit. The screws were implanted and perforating the root of incisor so as to touch the PDL directly. The PLLA screw was assigned as test and anionized titanium screws as control. Totally 18 PLLA and 18 anionized titanium screws were used in this experiment. At the end of each group rabbits were sacrificed and the biopsy block samples were collected and prepared with HE stain for light microscopic histomorphlogical evaluation. One of the same pack of PLLA and anionized titanium screws were also used for SEM evaluation for its surface characteristic which might affect the tissue response. The SEM showed even distributed micro-porosity of the anionized titanium screw. A wide variation on the PLLA, smooth on the convex of the screw and micro-groove and crack line on the concave of the screw. The histology showed PDL cells can repopulate on both PLLA and titanium screw at four week samples. The direction of PDL fiber does not totally parallel the screw surface but focus constricted to the most concavity of the screw. The direct bone screw contact can be seen and the density of surrounding bone and the amount of direct bone screw contact increasing by the time from four to twelve weeks period. This study shows the possibility of the repopulation and forming new attachment of PDL cell and possible functional non-paralleled fiber alignment on both PLLA and anionized titanium screw surface. With this cell and tissue conducting pattern, we might be able to develop new biomaterial or new clinical application without following the principle of guided tissue regeneration.

並列關鍵字

Periodontal tissue ； Guided tissue regeneration ； Tissue barrier ； poly-L-lactic acid(PLLA) ； Anionized titanium

參考文獻

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