Friedman S, Liu M, Izawa T, Moynihan M, Dörscher-Kim J, Kim S
Hebrew University, Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
Proc Finn Dent Soc. 1992;88 Suppl 1:167-71.
CO2 laser may be beneficially applied to teeth in preventive and restorative dentistry, but its physiopathologic effects on the dental pulp have not been reported. To address the dynamic pulpal changes induced by CO2 laser the purpose of this study was to examine such changes in pulpal microcirculation. The enamel surfaces of 4 cat canines were irradiated by CO2 laser beam, delivered by either a handpiece or microslad with a focal spot diameter of 0.21mm and 0.33mm, respectively. Exposure powers of 2.6-20 W were used for durations of 0.05-0.2 sec, resulting in energy density range of 304-1440 J/cm2. Non-invasive measurement of pulpal blood flow (PBF) by a laser Doppler flowmeter was maintained continuously before and following CO2 laser irradiation. CO2 laser irradiation resulted in an immediate increase in PBF, which subsided after 2-3 min. Large pulps responded with a significantly higher PBF increase than small pulps. These results confirm that CO2 laser irradiation of the tooth surface has a thermal effect on the pulp, which is moderated by the insulating capability of dentin. It appears that the associated thermal damage is not extensive when laser exposure parameters are such as used herein.
二氧化碳激光可有益地应用于预防和修复牙科中的牙齿，但其对牙髓的生理病理影响尚未见报道。为了研究二氧化碳激光引起的牙髓动态变化，本研究的目的是检查牙髓微循环中的此类变化。用聚焦光斑直径分别为0.21mm和0.33mm的手持件或微型载玻片发射的二氧化碳激光束照射4只猫犬齿的釉质表面。曝光功率为2.6 - 20W，持续时间为0.05 - 0.2秒，能量密度范围为304 - 1440J/cm²。在二氧化碳激光照射前后，用激光多普勒血流仪对牙髓血流（PBF）进行连续的非侵入性测量。二氧化碳激光照射导致PBF立即增加，2 - 3分钟后恢复。大牙髓对PBF增加的反应明显高于小牙髓。这些结果证实，牙齿表面的二氧化碳激光照射对牙髓有热效应，这种效应受牙本质绝缘能力的调节。当激光暴露参数如本文所用时，相关的热损伤似乎并不广泛。
