| 摘要: | 研究目的: 身心障礙人士受到心理或生理上的限制，常因日常口腔照護不易而引起嚴重的口腔疾病，連帶影響全身的健康。牙根齲齒是身障人士最常發生的口腔疾病之一；另一常見問題是牙齦萎縮，易造成齒質損傷並使牙本質小管暴露，引起病患牙齒敏感不適。本研究目的為研發一種嶄新的複合材料，不僅能對致齲菌轉醣鏈球菌有抑制效果，降低齲齒發生率，並減輕牙本質小管通透開口暴露所引發之疼痛。
研究方法: 轉醣鏈球菌與等量0.125%、0.25%、0.5%、1.0% (w/w)濃度之ε-聚離胺酸分別作共同培養，在特定時間點塗盤數菌，測試各濃度抗菌能力。五種不同的飽和鈣鹽溶液: 磷酸二鈣(DCPD)、一水磷酸二氫鈣(MCPM)、磷酸四鈣(TTCP)、碳酸鈣(calcium carbonate)和氯化鈣(calcium chloride)與0.125%、0.25%、0.5%、1.0% ε-聚離胺酸混合後之沉澱物以XRD及FTIR分析，上清液與等量的轉醣鏈球菌分別作共同培養，測試其抗菌能力。牙本質小管閉合試驗利用被拔除之人類臼齒製成牙本質試板，經表面處理模擬暢通的牙本質小管。五種飽和鈣鹽溶液先以牙科用小棉棒塗佈於試板表面，再塗抹0.125%、0.25%、0.5%、1.0% ε-聚離胺酸。樣本分為三組，0小時組經處理後自然風乾；72小時組浸泡在人工唾液中72小時; 酸蝕模擬組則浸泡人工唾液72小時後再經食用醋浸泡五分鐘；再以SEM作分析。
結果:實驗結果顯示共同培養一小時後，受試濃度的ε-聚離胺酸皆出現抑菌能力，十一小時後0.5% 和1.0 %濃度組達到轉醣鏈球菌的完全抑制，二十四小時後所有濃度皆達完全抑制。ε-聚離胺酸的抑菌力會受鈣源影響而降低，MCPM和氯化鈣兩組受影響最深，無法完全抑菌。XRD顯示DCPD加上0.125% ε-聚離胺酸沉澱物內含DCPD；其餘濃度組沉澱為非晶形沉澱；MCPM組則皆有MCPM的沉澱。FTIR分析顯示碳酸鈣組有碳酸鈣的沉澱，TTCP及氯化鈣組則無法辨認出沉澱物的結構。SEM分析顯示在0小時組，閉合牙本質小管開口能力較佳的組別為TTCP、DCPD和碳酸鈣；經72小時人工唾液浸泡後，DCPD組小管開口沉澱均存在。模擬酸蝕後的樣本中DCPD組仍有沉澱物存在於小管開口，顯示有良好且長效的去敏效果。
結論: ε-聚離胺酸是一種天然且安全的抗菌物質，對轉醣鏈球菌的抑制性顯露出極高的預防齲齒潛力。利用ε-聚離胺酸與富含鈣磷離子的溶液可預期能同時達到預防齲齒及再礦化修復的效果。在本次實驗中最具潛力的配方為DCPD加上0.5%及1.0%的ɛ-聚離胺酸以及碳酸鈣加上0.5%的ɛ-聚離胺酸，未來仍需進行動物與臨床人體試驗。
Objective: Oral health problem is an issue for disabled person due to the lack of ability to keep fair oral hygiene. Dental root caries is one of the most common oral problems for disabled person. Gingival recession is another common issue; it may cause exposure of open dentinal tubules and induce dentin hypersensitivity. The aim of this study is to investigate a new complex material, which may both fight against cariogenic pathogen: Streptococcus mutans and reduce the painful sensation of dentin hypersensitivity.
Method: Mixtures of equal volume of S. mutans with 0.125%, 0.25%, 0.5%, 1.0 % (w/w) ε-polylysine were incubated respectively to test the antimicrobial ability of ε-PL. Five different kinds of saturated calcium salt solutions: DCPD, MCPM, TTCP, calcium carbonate and calcium chloride were mixed with 4 different concentrations of ε-PL seperately. The precipitates of the mixtures were examined with XRD and Fourier transform IR analysis. The antimicrobial abilities of supernatants were examined. The dentinal tubule occlusion test was conducted by using dentinal discs of extracted human molars; the open tubules were simulated by etching with 1 M acetic acid for 10 seconds then rinsed with distilled water for 10 sec. Five saturated calcium salt solutions were first rubbed on the disc surface and secondly 0.125%, 0.25%, 0.5%, 1.0 % ε-PL using disposable dental resin applicators. The processed disc samples were divided into three groups, the 0 hour group was placed to air dried; the second group was immersed in artificial saliva for 72 hours; the third group was soaked in cooking vinegar for 5 minutes. All groups were analyzed with SEM.
Results: The results showed after mutual incubation for 1 hr, all ε–PL concentrations showed good antimicrobial ability. After 11 hours incubation, 0.5% and 1.0 % ε–PL showed total inhibition of S. mutans. After 24 hours incubation, all concentrations had reached total inhibition. XRD showed DCPD+0.125% ε–PL group had DCPD precipitation, other concentrations showed amorphous precipitates; MCPM groups all had MCPM precipitates. FTIR analysis showed calcium carbonate had calcium carbonate precipitation; but TTCP and calcium chloride precipitates could not be identified. SEM analysis showed in 0 hr group, TTCP, calcium carbonate and DCPD groups showed good tubules occlusion result; in 72 hrs group, DCPD had the best tubules occlusion result; in the acid-etching simulation group, DCPD group still had the dentinal tubules occluded.
Conclusion: ε–PL is a natural and safe antimicrobial product, showing great potential in caries prevention. Combine ε–PL with calcium and phosphate rich solution maybe an answer for both caries control and remineralization repair. 0.5% ε–PL + CaCO3 and 0.5, 1.0% ε–PL + DCPD groups have instant, rapid and durable effect for dentin hypersensitivity relief and still have good anti-S. mutans ability. Further antimicrobial tests and applications in vivo are needed. |
