Kohns P, Zhou P, Störmann R
Optikzentrum NRW, Bochum, Germany.
J Laser Appl. 1997 Jun;9(3):171-4. doi: 10.2351/1.4745457.
We present a feasibility study into laser treating dental materials by using femtosecond pulses generated by a titanium:sapphire laser system which consisted of an oscillator and a regenerative amplifier. The pulse duration was varied between 200 fs and 2 ps. The observed energy thresholds for the ablation process of dentine and enamel were clearly smaller than those observed when longer pulse durations were used. The consequence of this observation is a lower thermal load within the vicinity of the radiated area. Thus no thermal damage or mechanical damage, such as cracks, were produced during the laser treatment. Commercially available femtosecond laser systems can produce ablation rates in healthy and in-vitro demineralized dental material 2 mm3 per min and 6-16 mm3 per min, respectively. These values are an order of magnitude larger than those produced by picosecond laser systems at the same time pulse energy and pulse repetition rate. The brightness of the plasma spark generated by the laser treatment depended on the dimineralization of the teeth. This may allow online control of the laser treatment.
我们开展了一项可行性研究，利用由钛宝石激光系统产生的飞秒脉冲来激光处理牙科材料，该系统由一个振荡器和一个再生放大器组成。脉冲持续时间在200飞秒至2皮秒之间变化。观察到的牙本质和牙釉质消融过程的能量阈值明显低于使用较长脉冲持续时间时观察到的阈值。这一观察结果的结果是辐射区域附近的热负荷较低。因此，在激光治疗过程中不会产生热损伤或机械损伤，如裂纹。市售的飞秒激光系统在健康和体外脱矿的牙科材料中分别可产生每分钟2立方毫米和每分钟6 - 16立方毫米的消融速率。这些值比皮秒激光系统在相同脉冲能量和脉冲重复率下产生的值大一个数量级。激光治疗产生的等离子体火花的亮度取决于牙齿的脱矿情况。这可能允许对激光治疗进行在线控制。
