Application of CaO-P2O5-B2O3 Glass System on the Root Canal Treatment

所謂根管治療，是將根管內受感染的牙髓組織移除，最後再使用根管封填材料放入牙根空腔使其密封，阻斷微生物再次經根管系統造成組織感染。然而根管系統的複雜程度超乎想像，相同的牙齒中也存在極大的變異性，彎曲的根管在臨床的治療也是一大挑戰，殘存的微生物便會造成持續的症狀，導致未來根管治療的失敗。目前市面尚無任何材料可以深入牙本質小管中，抑制細菌增長同時封閉牙本質小管。根據本團隊先前的研究，DP-生醫玻璃與30%磷酸調拌後，能在牙本質小管中形成結晶，有效的封閉牙本質小管。 本研究目的為開發一個新鈣磷硼系玻璃，並製作玻璃製劑使其性質產生pH值4左右的酸性環境，能夠釋放鈣離子與磷酸根離子形成再結晶沉澱，有效封閉牙本質小管。本研究第一部分為材料製備，透過高溫熔融及研磨的過程得到微米級玻璃粉末。第二部分為材料分析，目的確認玻璃系統的性質。第三部分為牙本質模型實驗，使用臨床上拔除之人類恆牙來模擬真實牙齒環境，切取牙本質試片測試玻璃製劑是否達到預期牙本質小管封閉。最後一部分進行生物相容性測試，為牙科材料上市前做基本的細胞活性與毒性試驗。 總結實驗結果，本研究以高溫熔融製程可合成出具有高P2O5含量的鈣磷硼系玻璃，BCP-G製劑可在1小時內產生pH值2以下的酸性環境，在人類牙本質模型塗抹測試中，與氫氧化鈣混合的BCP-G-0.1CH製劑可以在24小時內能有效的進入且封閉牙本質小管，並且利用材料萃取液測試結果有良好生物相容性，因此，BCP-G-0.1CH製劑在未來可針對根管治療提供更完善的對策並提高根管治療的成功率。The main objective of root canal therapy is to through mechanical and chemical cleaning of the entire pulp cavity and completes the occlusion with filling materials. It is obvious that the result of root canal therapy depends on their reduction or elimination of the microorganisms for lesions. However, total elimination of bacteria is difficult to accomplish. The complexity of the root canal system is the main challenge for any dentist undertaking root canal treatment. Nowadays, there is no commercial products can effectively seal dentin tubules. According to previous study in our laboratory, DP-bioglass has demonstrated 60μm of sealing depth in dentin tubules. The purpose of this study is to develop a CaO-B2O3-P2O5 glass system (BCP-glass) which can release more calcium ion and phosphate ion in order to seal dentin tubules. Furthermore, the glass system will be mixed with gelatin solution. Firstly, reaching the eutectic point through high temperature melting process, the BCP-glass powder is generated and mixed with 3% gelatin solution(G) and calcium hydroxide(CH) to mimic paste-like formation. Then, using the BCP-G-0.1CH paste on the human dentin disc model to observe the sealing ability. Finally, the biocompatibility of BCP-G-0.1CH paste is investigated. The results showed that BCP-glass powder with high P2O5 had been made successfully. The group of BCP-G-0.1CH paste demonstrated 70 μm of sealing depth in dentin tubules in 24 hours. Moreover, BCP-G-0.1CH paste also showed good biocompatibility in WST-1 and LDH assay. In conclusion, BCP-G-0.1CH paste has a potential of dentin tubules occlusion and provides a novel method in root canal therapy