Er:YAG激光照射对牙体硬组织表面结构和形态学影响的实验研究

发布时间：2018-07-10 14:31

本文选题：Er:YAG激光 + 牙釉质　；参考：《第三军医大学》2017年硕士论文

【摘要】：研究背景龋病是人类的常见病与高发病,它严重影响人类的口腔健康。目前,临床常用的龋病治疗方法为充填治疗,但是涡轮机在切割牙体组织时所产生的负压会导致牙本质敏感甚至疼痛,而噪声及震动又增加了患者的牙科畏惧。1997年,美国食品药品管理局(FDA)批准掺铒钇铝石榴石(Er:YAG)激光可用于治疗牙体硬组织疾病,自此,Er:YAG激光逐渐被应用于龋病的治疗当中。Er:YAG激光切割牙体组织具有无噪声、无震动、无痛、精准切割等优点,得到了越来越多患者的接受和认可。虽然Er:YAG激光具备有上述优点,但是如何提高Er:YAG激光对牙体硬组织的切割效率也是当前研究的热点。Er:YAG激光对牙体硬组织的切割主要取决于能量、频率、照射时间、喷水量等因素。目前的实验研究和临床操作多通过改变Er:YAG激光的能量来提高切割能力,然而关于频率对牙体硬组织切割能力的影响则鲜有报道。目的本研究通过测量Er:YAG激光不同频率和照射时间下牙釉质和牙本质表面凹坑直径、深度的变化,同时观察表面形态学变化,得出Er:YAG激光切割牙体硬组织最佳的频率和时间参数,为提高Er:YAG激光备洞的效率和安全性提供依据。材料与方法1.收集离体前磨牙80颗,要求离体牙表面无龋坏、无裂纹、无釉质发育不全、非氟斑牙,制备牙釉质样本和牙本质样本各80个(4mm×4mm×2.5mm)。根据Er:YAG激光照射时间不同,将80个牙釉质样本和80个牙本质样本按随机数字表法分为照射10s和照射20s两个大组,每组40个样本,然后每大组再分为5个亚组(按Er:YAG激光频率10Hz、15Hz、20Hz、25Hz、30Hz),每组8个样本。按以上分组对每个样本进行Er:YAG激光照射,Er:YAG激光能量固定为200m J。Er:YAG激光照射后,使用体视显微镜观察样本表面的凹坑,并测量其直径和深度。2.收集离体前磨牙80颗,要求同上,制备牙釉质样本和牙本质样本各80个(4mm×4mm×2.5mm),分组同上,使用Er:YAG激光照射,然后各亚组抽取2个样本,在扫描电镜下观察表面形态学变化,选取代表性的区域进行拍照。3.选取2015年10月至2016年3月到本院口腔内科就诊的年龄为12-55周岁龋病患者30例,要求患者口内同颌或对颌至少有2颗磨牙的龋坏程度相似(以樊明文主编的《牙体牙髓病学》诊断标准为准),有牙髓炎、根尖周炎等症状患者以及不愿意接受Er:YAG激光治疗的患者排除。将30名患者分为两组:Er:YAG激光组(Er:YAG激光的能量为200m J、频率为20Hz)及高速涡轮机组,对患牙龋坏进行去除,分别记录两组去龋所用的时间,使用视觉模拟评分法(VAS)记录患者的疼痛程度,垫底后Z350复合树脂充填窝洞,调合,抛光。嘱患者1、3、6、12个月后复查,观察充填体的边缘是否着色、有无充填体脱落及继发龋。结果1.Er:YAG激光照射后,牙釉质和牙本质表面凹坑直径及深度随着激光频率增加和照射时间延长呈增加趋势。当照射时间一致时,Er:YAG激光频率为10-20Hz时,凹坑直径和深度的增加速度快,差异有统计学意义(P0.05);而频率增加到25-30Hz时,凹坑直径和深度增加则相对平缓,差异无统计学意义(P0.05);当激光频率相同时,照射10s后的牙釉质和牙本质表面凹坑直径及深度均显著小于照射20s后的凹坑直径及深度,两者差异具有统计学意义(P0.05)。2.扫描电镜下观察显示,当Er:YAG激光频率为10-20Hz时,牙釉质表面粗糙、不规则,可见鱼鳞样的釉柱结构,随着频率增加,当频率达到25-30Hz时,凹坑表面稍显平坦,鱼鳞样的釉柱结构消失,凹坑局部可见裂纹及部分熔融现象;Er:YAG激光照射后,牙本质凹坑表面清洁、无玷污层,牙本质小管开放,随着激光频率增加和照射时间延长,牙本质小管开放的数目增多,Er:YAG激光频率25Hz,照射时间为20s时,牙本质凹坑表面可见裂纹,当频率继续增加到30Hz、照射时间为10s及20s时,裂纹更深,可见局部熔融的牙本质堵塞部分牙本质小管,使牙本质小管开放的数目减少。3.Er:YAG激光组去龋的平均时间(158.4±32.8s)显著大于高速涡轮机组去龋的平均时间(93.6±42.5s),差异有统计学意义(P0.05);VAS显示患者更容易接受Er:YAG激光去龋(P0.05);充填1、3、6、12个月后患者复查,Er:YAG激光组和高速涡轮机组去龋后充填体边缘着色、充填体脱落及继发龋情况无统计学差异(P0.05)。结论1.Er:YAG激光照射牙体硬组织时,选择激光能量200m J,频率10-30Hz,照射时间10s及20s,牙体硬组织表面凹坑的直径和深度随着激光频率增加和照射时间延长呈增加趋势。2.Er:YAG激光照射牙体硬组织时,选择激光能量200m J,频率10-20Hz,照射时间10s及20s,牙釉质和牙本质表面不会出现裂纹、熔融等热损伤现象;而使用较高频率的Er:YAG激光(25-30Hz)照射牙釉质和牙本质10s及20s后,表面有裂纹、熔融等热损伤现象产生。3.Er:YAG激光频率为20Hz、照射时间为20s时,牙体硬组织表面可获得有效、安全的切割。4.和高速涡轮机去龋相比较,Er:YAG激光去龋可明显减轻患者的痛苦,而且两者去龋后充填体的疗效没有统计学差异。
[Abstract]:Background caries is a common and high incidence of human disease. It seriously affects human oral health. Currently, dental caries are commonly used in the treatment of dental caries. However, the negative pressure produced by turbine in cutting tooth tissue causes dentin sensitivity and even pain, while noise and vibration increase the patient's dental fear for.1997 years, The US Food and Drug Administration (FDA) approves that erbium - doped yttrium aluminum garnet (Er:YAG) laser can be used to treat dental hard tissue diseases. Since the Er:YAG laser is gradually applied to the treatment of dental caries, the.Er:YAG laser cutting tooth tissue has the advantages of no noise, no vibration, painless, accurate cutting and so on, which has been accepted and accepted by more and more patients. Although the Er:YAG laser has the above advantages, how to improve the cutting efficiency of Er:YAG laser for tooth hard tissue is also a hot spot of current research. The cutting of hard tissue of the tooth is mainly dependent on the factors of energy, frequency, time of irradiation, and the amount of water, and so on. The current experimental research and clinical operation are mostly by changing the Er:YAG laser. Energy is used to improve the cutting ability. However, the effect of frequency on the ability of tooth hard tissue cutting is rarely reported. Objective the purpose of this study was to measure the depth changes of the surface of the enamel and dentin surface in different frequencies and exposure time of Er:YAG laser, and to observe the changes in surface morphology, and to obtain the hard tissue of the tooth by Er:YAG laser. The optimum frequency and time parameters provide the basis for improving the efficiency and safety of Er:YAG laser cavity. Material and method 1. collect 80 premolar teeth in vitro, require no dental caries, no crack, non enamel development, non fluorosis, 80 dental enamel samples and 80 dentine samples (4mm x 2.5mm). According to Er:YAG laser The 80 dental enamel samples and 80 dentin samples were divided into two groups of irradiated 10s and 20s, each group was divided into 40 samples, and then each group was divided into 5 subgroups (10Hz, 15Hz, 20Hz, 25Hz, 30Hz) in each group (Er:YAG laser frequency 10Hz, 15Hz, 20Hz, 25Hz, 30Hz), and each group was irradiated with Er:YAG laser, Er:Y. After AG laser energy was fixed to 200m J.Er:YAG laser, a stereoscopic microscope was used to observe the pits on the surface of the sample, and the diameter and depth of.2. were measured to collect 80 premolars in vitro. It was required that the enamel samples and dentin samples were prepared with 80 (4mm * 4mm x 2.5mm) samples, with the same group, the Er:YAG laser irradiation, and then 2 subgroups. The samples were examined under scanning electron microscope, and the representative area was selected to take a photo of.3. to select 30 cases of dental caries aged 12-55 years from October 2015 to March 2016, and the degree of dental caries was similar to that of at least 2 molars in the mouth of the mouth or at the maxillary. (with Fan Mingwen's editor's "tooth tooth" 30 patients were divided into two groups: the Er:YAG laser group (the energy of 200m J, the frequency of 20Hz) and the high speed turbine unit to remove the dental caries and record the two groups of decayed caries, respectively, in the patients with pulpitis, periapical periodontitis and other patients who were not willing to receive Er:YAG laser treatment. A visual analogue scale (VAS) was used to record the degree of pain in patients with Z350 composite resin filling pit, blending, and polishing. The patients were reviewed after 1,3,6,12 months to observe whether the edge of the filling body was coloured, the filling body fell off and secondary caries. Results the diameter and depth of the enamel and dentine surface pits after the 1.Er:YAG stimulated light irradiation With the increase of laser frequency and exposure time, when the frequency of Er:YAG laser is 10-20Hz, the diameter and depth of the concave pit increase faster, and the difference is statistically significant (P0.05); while the increase of the frequency to 25-30Hz, the diameter and depth of the pits is relatively flat, and the difference is not statistically significant (P0.05). When the laser frequency is the same, the diameter and depth of the concave pit of the enamel and dentin surface after 10s irradiation are significantly less than the diameter and depth of the pits after the irradiation of 20s. The difference has statistical significance (P0.05). Under the.2. scanning electron microscope, when the Er:YAG laser frequency is 10-20Hz, the enamel surface is rough and irregular, and the scale like glaze column can be seen. As the frequency increases, when the frequency reaches 25-30Hz, the surface of the pit is slightly flat, the structure of the enamel like glaze disappears, the cracks and partial melting can be seen in the pits. After the Er:YAG laser irradiation, the surface of the dentine pit is clean, the defiling layer is untarnished, the dentinal tubule opens, and the dentine is small with the increase of the frequency of the laser and the prolongation of the time of the laser irradiation. When the number of open tubes increased, the Er:YAG laser frequency 25Hz and the irradiation time were 20s, the surface of the dentine dent was visible. When the frequency continued to increase to 30Hz, the time of irradiation was 10s and 20s, the crack was deeper, and the partially fused dentin blocked the partial dentinal tubules and reduced the number of open dentine tubules to decrease the decayed caries in the.3.Er:YAG laser group. The average time (158.4 + 32.8s) was significantly greater than the average time (93.6 + 42.5s) for high speed turbo caries, and the difference was statistically significant (P0.05); VAS showed that patients were more likely to accept Er:YAG laser decayed caries (P0.05); after filling 1,3,6,12 months, patients were rechecked, Er:YAG laser group and high speed turbine set after caries filling body edge coloring, filling body fall off There is no significant difference in the secondary caries (P0.05). Conclusion when 1.Er:YAG laser irradiated the hard tissue of the tooth, the laser energy 200m J, the frequency 10-30Hz, the irradiation time 10s and 20s, the diameter and depth of the hard tissue surface pits of the tooth body are increased with the increase of the laser frequency and the irradiation time, and the.2.Er:YAG laser irradiation on the hard tissue of the tooth body is selected. Selective laser energy 200m J, frequency 10-20Hz, irradiation time 10s and 20s, the tooth enamel and dentin surface will not appear crack, melting and other thermal damage phenomena, while the high frequency Er:YAG laser (25-30Hz) irradiate the tooth enamel and dentin 10s and 20s, the surface cracks, melting and other thermal damage phenomenon of.3.Er:YAG laser frequency is 20Hz, irradiation. At the time of 20s, the surface of the hard tissue of the tooth can be effective. The safe cutting.4. and the high speed turbine are compared. The Er:YAG laser decayed caries can obviously reduce the sufferings of the patients, and there is no statistically significant difference in the curative effect of the two cases after the decayed caries.
【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R781.1

【参考文献】