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Title: | 含氟化高嶺土填料與兒茶素接枝改質之抑菌型牙科複合樹脂 Bacteriostatic Dental Composite Resin Containing Fluorinated Kaolinite Fillers and Immobilized Epigallocatechin Gallate |
Authors: | Kuan-Han Lee 李冠翰 |
Advisor: | 姜昱至 |
Keyword: | 複合樹脂,繼發性齲齒,兒茶素,氟化高嶺土,生物膜,抑菌效果, Composite resin,Secondary caries,Epigallocatechin gallate,Fluorinated kaolinite,Biofilm,Bacteriostatic effect, |
Publication Year : | 2015 |
Degree: | 碩士 |
Abstract: | 複合樹脂近年來已成為廣泛運用之牙科臨床填補材料,因其具有齒色優美外觀、直接操作與費用低廉等優點,但在光照聚合後產生的體積收縮使牙齒與填補物之間易造成邊緣性滲漏,再加上複合樹脂本身大多缺乏抗齲齒菌能力,使表面容易聚集細菌貼附而形成生物膜,最終造成繼發性齲齒的發生,也是導致複合樹脂失敗最主要的原因。 兒茶素(EGCG)為茶葉茶多酚裡主要成分,具有多樣作用如抗氧化、抗發炎、抗菌,根據研究,EGCG在15.6 µg/ml可以有效抑制90%轉糖糖鏈球菌的生物膜形成,而氟素可以幫助牙齒表面再礦化、減少去礦化、干擾與抑制微生物的生長與代謝。因此本研究目的為研發含氟化高嶺土填料與兒茶素接枝改質複合樹脂,利用高嶺土層狀結構對氟離子良好的吸附效果,合成高嶺土-丙烯醯胺含氟複合物當作複合樹脂中的部分無機填料,讓材料能穩定釋放並再吸收氟素。另外將EGCG做改質,使之在複合樹脂光固化後可接枝在有機基質上,確保材料抑菌的效果。 本研究共分為四部分進行,第一部分為實驗複合樹脂合成。包含有機基質合成、EGCG改質、氟化高嶺土填料及氧化鋁無機填料合成。第二部分為材料性質分析與測試。包含表面微硬度與直徑抗拉強度測試,並且以電子顯微鏡觀察實驗合成複合樹脂斷面及利用能量散射光譜儀分析元素比例與分布狀況。第三部分為材料抑菌效果測試,選用主要致齲齒細菌–轉糖糖鏈球菌為測定目標,以細菌直接接觸法進行複合樹脂錠片表面生物膜培養,再檢測細菌懸浮液光密度值與菌落形成單位多寡,錠片表面以電子顯微鏡觀察轉糖糖鏈球菌生物膜分部狀況,並搭配共軛焦雷射顯微鏡影分析,將死菌與活菌透過紅綠螢光訊號呈現,且量化紅綠螢光訊號強度。第四部分為材料生物相容性測試,利用人類牙髓細胞與複合樹脂進行WST-1細胞增殖測試與乳酸脫氫酶細胞毒性測試。 實驗結果顯示本實驗研發之含氟化高嶺土填料與兒茶素接枝質複合樹脂,在電子顯微鏡觀察下,有機基質與氟化高嶺土填料能夠良好結合而不易脫落,且以能量散射光譜儀分析證實有氟元素存在;物理性質部分,直徑抗拉強度與市售材料相當,但表面微硬度略低於市售材料,因此未來仍須針對此部分進行改良;抑菌效果方面,當加入1000 ppm EGCG與重量比30%氟化高嶺土後的複合樹脂,已能達到良好抑菌效果,優於市售含氟商品Beautifil II與Fuji II LC,且對人類牙髓細胞有良好之生物相容性,故本實驗研發之複合樹脂在臨床應用上對於預防繼發性齲齒具有相當的發展潛力。 Dental composite resin has been widely used as clinical restorative filling material because of its tooth-color appearance, direct filling technique and lower cost. However, the nature of polymerization shrinkage of light-curing composite resin would cause marginal leakage between tooth and restoration. The lack of anti-bacterial ability will give rise to bacteria adhesion and biofilm formation. Consequently, secondary caries take place, which contributed to the major failure reason for the composite resin. The epigallocatechin gallate (EGCG), the main component of tea polyphenols in tea leaves, which presents important physiological properties such as anti-oxidation, anti-inflammation and anti-bacterial etc. According to previous study, 15.6 µg/ml EGCG showed at least 90% inhibition of streptococcus mutans (S. mutans) biofilm formation. In addition, not only does fluoride promote tooth remineralization but it also helps to create an environment for the resistance of microbial growth and metabolism. Therefore, the objects of this study were (1) to development a novel dental composite resin containing fluorinated kaolinite fillers and epigallocatechin gallate. Kaolinite (Al2Si2O5(OH)4), a clay mineral, has been known for its ability to carry and absorption of fluoride due to the layered aluminosilicate structure; (2) to test its anti-bacterial and physical properties. By means of kaolinite, we synthesized fluoridated kaolinite-acrylamide compound as kind of inorganic filler, which will facilitate continuous fluoride release and recharge of experimental composite resin. Furthermore, the EGCG immobilized organic matrix perform significant bacteriostatic effect after light-curing polymerization. This study was carried out in four parts: Part 1:Synthesis of experimental composite resin, including organic matrix, EGCG modification, fluorinated kaolinite fillers and aluminum oxide fillers. Part 2:Material analysis and physical properties evaluation, including surface microhardness and diametral tensile strength. Fractography were examined by scanning electron microscope (SEM). Energy dispersive spectroscopy (EDS) were also conducted for analysis of element ratio and distribution. Part 3:Bacteriostatic assessment. We used S. mutans as our experimental target bacteria, the major cariogenic microorganism responses for dental caries. By means of direct contact with bacterial solution, S. mutans biofilm were formed on composite resin disk surface. We detected the bacterial suspension optical density and colony forming unit per milliliter. The distribution of S. mutans biofilm were observation by SEM. Moreover, the dead and live bacteria were convert to the red and green fluorescence signal through confocal laser microscope. Fluorescence signal intensity were quantified by computer software. Part 4:Biocompatibility test. Human dental pulp cell for WST-1 cell proliferation test and lactate dehydrogenase cytotoxicity assay were performed. The results showed that experimental composite resin can well integrate fluorinated kaolinite inorganic fillers and organic matrix without exfoliation under SEM observations. EDS element analysis confirmed the presence of fluoride. As for physical properties, diametral tensile strength is comparable to commercial products. The surface microhardness appeared slightly lower than commercial products due to its lower filler content compared to commercial filler loading. When experimental composite resin incorporating 30% weight ratio of fluorinated kaolinite and immobilized 1000 ppm EGCG, the bacteriostatic effect was prominent compared to commercial fluorinated material–Beautifil II and Fuji II LC (p<0.05). We believed that this novel dental composite resin has great potential of clinical applications in the future. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/52397 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 臨床牙醫學研究所 |
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