Stratmann U, Schaarschmidt K, Schürenberg M, Ehmer U
Institute of Anatomy, University of Münster, Germany.
Scanning Microsc. 1995 Jun;9(2):469-76; discussion 476-8.
This study investigated enamel laser conditioning as an alternative to acid etching in bracket therapy. In preliminary experiments optimal laser parameters for achieving a bond strength of 6-10 N/mm2 were defined. Enamel surface morphology was assessed and the ablation depth was measured on serial enamel sections. Thirty human molars were exposed to 193 nm ArF-excimer laser radiation (energy density: 260 mJ/cm2) by single pulse application of 23 nanoseconds. Thirty molars were etched with phosphoric acid (37%) for 60 seconds. The brackets from the treated molars and 30 untreated molars were debonded vertically for tensile bond strength measurement. Roughened enamel surfaces were attained by 450 and 900 laser pulses with a mean ablation depth of 10.13 +/- 4.84 microns. After 1-10 laser pulses, the enamel surface appeared intact. The tensile bond strength was 6.63 +/- 2.18 N/mm2 in the laser-treated group (1 pulse), 8.75 +/- 3.61 N/mm2 in the acid-etched group, and 4.61 +/- 3.15 N/mm2 in the untreated group. We conclude a laser-selective ablation of the membranous enamel pellicle. Since the irradiated area can be adapted to bracket base and the enamel surface remains morphologically intact, pulsed ArF-excimer laser treatment seems to be superior to the acid etching technique.
本研究调查了在正畸治疗中，使用激光处理牙釉质作为酸蚀替代方法的效果。在初步实验中，确定了能达到6-10N/mm2粘结强度的最佳激光参数。评估了牙釉质表面形态，并在连续的牙釉质切片上测量了消融深度。30颗人类磨牙通过单次施加23纳秒的193nm氟化氩准分子激光辐射（能量密度：260mJ/cm2）进行处理。30颗磨牙用37%的磷酸酸蚀60秒。将处理过的磨牙和30颗未处理磨牙上的托槽垂直脱粘以测量拉伸粘结强度。通过450和900次激光脉冲获得了粗糙的牙釉质表面，平均消融深度为10.13±4.84微米。在1-10次激光脉冲后，牙釉质表面看起来完好无损。激光处理组（1次脉冲）的拉伸粘结强度为6.63±2.18N/mm2，酸蚀组为8.75±3.61N/mm2，未处理组为4.61±3.15N/mm2。我们得出结论，激光可选择性消融牙釉质表面的薄膜。由于照射区域可与托槽底部适配，且牙釉质表面在形态上保持完整，因此脉冲氟化氩准分子激光治疗似乎优于酸蚀技术。
