矽酸鈣材料（Calcium silicate-based material，CS）已成功且廣泛的運用在牙科臨床上。過去研究顯示，由於CO2雷射的光熱機制，讓CO2雷射具有良好的抗菌能力。本研究的目的除了分析CO2雷射的照射對於 CS 材料特性的影響外，也同時對於人類牙周韌帶細胞（human periodontal ligament cells，hPDLs）的生物性質進行評估。本研究將hPDLs培養於CS上，並使用牙科CO2雷射且裝製 0.25 cm2 光點面積雷射光纖頭並且刺激細胞，後續再分析細胞的生長以及牙本 質分化的研究。結果顯示，CO2雷射的照射可以增加CS中鈣離子和矽離子釋放至培養液的濃度，並影響細胞的生理行為。此外，CO2雷射照射也會促進 hPDLs細胞培養於CS上的牙本質分化以及骨礦化結節的形成，並且促進牙本質生成蛋白和黏附蛋白的生成表現。三氧礦化物 (Mineral trioxide aggregate，MTA)是一種生物性材料，近年來被廣泛的應用在臨床根管治療上，這篇研究我們也將分析經由CO2雷射照射後對於MTA材料特性及細胞能力的影響進行評估，實驗的結果是與CO2雷射照射CS後的表現是相同的，並且其固化時間在經由照射CO2雷射後為118分鐘與未照射CO2雷射相比是有顯著降低，在最大徑向拉伸強度和X-光繞射的結果是與未照射CO2雷射相似的。目前的研究結果提供了新的並且重要的數據在CO2雷射在照射CS 及MTA的影響，現階段的結果可得知CO2雷射照射CS和MTA是可以增加矽離子的，並且是低於造成細胞凋亡的臨界濃度，同時可以促進hPDLs的分化行為，這些結果在未來是有機會被應用於牙本質生成和牙周組織的再生醫學治療 。
Calcium silicate-based material (CS) has been successfully used in dental clinical applications. Studies show that the anti-bacterial effects of CO2 laser irradiation are highly efficient when bacteria are embedded in biofilm, due to a photo-thermal mechanism. The purpose of this study was to confirm the effects of CO2 laser irradiation on CS, with regard to both material characterization and human periodontal ligament cell (hPDLs) viability. CS was irradiated with a dental CO2 laser using directly mounted fiber optics in wound healing mode with a spot area of 0.25 cm2, and then stored in an incubator at 100% relative humidity and 37 °C for 1 d to set. The hPDLs cultured on CS was analyzed, along with their proliferation and cementogenic/odontogenic differentiation behaviors. The results indicate that the CO2 laser irradiation increased the amount of Ca and Si ions released from the CS, and regulated cell behavior. CO2 laser-irradiated CS promoted cementogenic/odontogenic differentiation of hPDLs, with the increased formation of mineralized nodules on the substrate’s surface. It also up-regulated the protein expression of multiple markers of cementogenic and the expression of cementum attachment protein. Mineral trioxide aggregate (MTA) was a biomaterial with several clinical applications in endodontics. We also were to confirm the effects of CO2 laser irradiation on MTA with regard to both material characterization and cell viability. The results were the same the effect of CO2 laser irradiation on CS, and the setting time after irradiation by the CO2 laser was significantly reduced to 118 minutes rather than the usual 143 minutes. The maximum diametral tensile strength and x-ray diffraction patterns were similar to those obtained without CO2 laser irradiation. The current study provides new and important data about the effects of CO2 laser irradiation on CS and MTA. Taking cell functions into account, the Si concentration released from CS and MTA with laser irradiated may be lower than a critical value, and this information could lead to the development of new regenerative therapies for dentin and periodontal tissue.
