Staninec Michal, Gardner Andrew K, Le Charles Q, Sarma Anupama V, Fried Daniel
University of California, San Francisco, California 94143-0758, USA.
J Biomed Mater Res B Appl Biomater. 2006 Oct;79(1):193-201. doi: 10.1002/jbm.b.30530.
The characteristics of laser-treated tooth surfaces depend on the laser wavelength, pulse duration, spatial and temporal laser beam quality, incident fluence, surface roughness, and the presence of water during irradiation. Ablated surfaces are most commonly restored with adhesive dental materials and the characteristics of the ablated surfaces influence adhesion of restorative materials. Previous studies suggest that high bond strengths can be achieved using shorter laser pulses that minimize peripheral thermal damage. In this study, Er:YSGG, Er:YAG, and CO(2) lasers were used at irradiation intensities sufficient to simulate efficient clinical caries removal to uniformly irradiate bovine enamel and human dentin surfaces using a motion control system with a microprocessor-controlled water spray. The degree of spatial overlap of adjacent pulses was varied so as to investigate the influence of irradiation uniformity and surface roughness on the bond strength. Composite resin was bonded to the irradiated surfaces and shear bond tests were used to obtain bond strengths in MPa. The highest results were obtained using the Er:YAG pulses with pulse durations less than 35 mus without the necessity for postirradiation acid etching. Some of these groups were not significantly different from nonirradiated, acid-etch-only positive control groups.
激光处理过的牙齿表面特征取决于激光波长、脉冲持续时间、激光束的空间和时间质量、入射能量密度、表面粗糙度以及照射过程中是否有水存在。被消融的表面通常用牙科粘结材料进行修复，而被消融表面的特征会影响修复材料的粘结。先前的研究表明，使用能将周边热损伤降至最低的较短激光脉冲可实现较高的粘结强度。在本研究中，使用铒：钇-钪-镓石榴石激光（Er:YSGG）、铒：钇铝石榴石激光（Er:YAG）和二氧化碳激光（CO₂），以足以模拟有效临床龋齿去除的照射强度，通过带有微处理器控制喷水的运动控制系统对牛牙釉质和人牙本质表面进行均匀照射。改变相邻脉冲的空间重叠程度，以研究照射均匀性和表面粗糙度对粘结强度的影响。将复合树脂粘结到照射过的表面，并使用剪切粘结试验以兆帕（MPa）为单位获得粘结强度。使用脉冲持续时间小于35微秒的Er:YAG脉冲获得了最高结果，且无需照射后酸蚀。其中一些组与未照射的仅进行酸蚀的阳性对照组没有显著差异。
