Niemz M H, Eisenmann L, Pioch T
Institut für Angewandte Physik, Universität Heidelberg.
Schweiz Monatsschr Zahnmed. 1993;103(10):1252-6.
Three different laser systems were compared according to their applicability in dentistry: a Ho:YAG laser (lambda = 2, 12 microns, pulse duration = 250 microseconds and 4 microseconds, pulse energy up to 300 mJ), an Er:YAG laser (lambda = 2,94 microns, pulse duration = 60-100 microseconds, pulse energy up to 100 mJ) and an in dentistry so far unknown picosecond Nd:YLF laser (lambda = 1,053 microns, pulse duration = 30 ps, pulse energy up to 1 mJ). The morphological changes of the enamel due to laser radiation were studied using light and scanning electron microscopy. Possible enamel fractures were visualized with dye penetration tests. Thermally caused, about 3 mm long enamel fractures were only observed using the Ho:YAG laser. Smaller fractures, up to 300 microns, were generated with the Ho:YAG and the Er:YAG laser. The Nd:YLF laser produced well defined square cavities with a high precision. No enamel fractures could be observed. The dye penetration in the cavity walls was less than 20 microns.
钬激光（波长λ = 2.12微米，脉冲持续时间 = 250微秒和4微秒，脉冲能量高达300毫焦）、铒激光（波长λ = 2.94微米，脉冲持续时间 = 60 - 100微秒，脉冲能量高达100毫焦）以及一种在牙科领域尚不为人知的皮秒钕：钇锂氟激光（波长λ = 1.053微米，脉冲持续时间 = 30皮秒，脉冲能量高达1毫焦）。利用光学显微镜和扫描电子显微镜研究了激光辐射导致的牙釉质形态变化。通过染料渗透试验观察可能出现的牙釉质骨折情况。仅在使用钬激光时观察到了热致的、约3毫米长的牙釉质骨折。钬激光和铒激光产生了长度达300微米的较小骨折。钕：钇锂氟激光产生了高精度的形状规整的方形空洞。未观察到牙釉质骨折。空洞壁上的染料渗透小于20微米。
