不同参数Er:YAG激光照射对根面形态及粗糙度的影响

目的:探讨不同脉冲能量、不同照射时间的Er:YAG激光对牙根面形态、粗糙度的影响,为Er:YAG激光用于牙周治疗提供依据和参数指导。方法:将收集的牙周病患牙在釉牙骨界质根方2 mm切割制备成5 mm×5 mm×2 mm的牙体组织块共45个,随机分为9组。一组仅进行手工刮治,其余8组在手工刮治后分别接受不同脉冲能量及不同时间的激光照射,表面粗糙度仪测治疗前后粗糙度,扫描电镜观察治疗后根面形态。结果:粗糙度:各组治疗后粗糙度显著降低(P<0.05),单纯手工刮治组的粗糙度最低为(0.58±0.06),手工刮治辅以不同参数激光的粗糙度大于单纯手工刮治组而小于治疗前(P<0.05);相同照射时间,粗糙度200 mJ/P>160 mJ/P>120 mJ/P>80 mJ/P,但80 mJ/P、120 mJ/P、 160 mJ/P 3组差异不显著;相同脉冲能量,粗糙度60 s>30 s,差异显著(P<0.05)。根面形态:单纯手工刮治组的根面光滑但有玷污层,手工刮治辅以激光照射的根面表层消融,形成层状或颗粒状粗糙外观,随脉冲能量增大和照射时间延长,表层组织消融增多。结论:手工刮治、手工刮治辅以不同参数Er:YAG激光均可降低牙周病牙根面粗糙度;Er:YAG激光辅助照射通过清除根面玷污层,消融根面表层组织,形成粗糙表面;粗糙度与照射时间呈正相关;脉冲能量小于160 mJ/P时,增大脉冲能量对根面粗糙度无显著影响。关键词] Er:YAG激光 根面形态 根面粗糙度

Effects of Er:YAG Laser Irradiation on Surface Morphology and Roughness of Tooth Roots

Objective: To investigate effects of Er:YAG laser irradiation with different radiation energies and times on the root surface morphology and roughness. Methods: Forty-five extracted teeth due to periodontitis were collected. The tooth roots below the cemento-enamel junction were cut into small pieces (5mm×5mm×2mm). They were randomly divided into 9 groups. The first group only received SRP, and other 8 groups received different parameters Er:YAG laser irridiation after SRP. Then the mean roughness (Ra) was measured and the morphology of root surfaces was observed. Results: After SRP or SRP＋Er:YAG laser, Ra was decreased obviously (P<0.05). The Er:YAG laser increased the Ra significantly than the only scaling group (P<0.05). With the increase of pulse energy and irradiation time, the root surface roughness increased. There was no significant difference among 80mJ/pulse, 120mJ/pulse, and 160mJ/pulse. The difference between 30s and 60s groups was statistically significant (P<0.05). The root surface after SRP was smoother with smear layer. Conclusion: SRP and SRP+Er:YAG can decrease the roughness of tooth root. Er:YAG laser can remove the smear layer of root surface and leave a uniform rough surface. Root surface roughness was positively correlated with the exposure time.