【作者】 卢礼；

【导师】 宋锦璘；

【作者基本信息】 重庆医科大学 ， 口腔临床医学， 2009， 硕士

【摘要】 低强度脉冲超声波(Low Intensity Pulsed Ultrasound,LIPUS)作为一种安全无创的治疗手段,具有促进骨和软组织修复的作用。牙周病系牙周组织的一种慢性炎症性疾病,其治疗关键是恢复已丧失牙周组织的结构和功能。基于牙周组织再生理论和LIPUS潜在的生物学效应,本研究初步探讨一定参数的LIPUS联合牙周翻瓣术或引导组织再生术对Beagle犬牙周病变组织的修复效应,为今后LIPUS辅助治疗牙周疾病提供前期参考。本实验在前期研究基础上改良LIPUS探头形态,设计新的固定方式,避免了探头固定操作中的人工误差、盲操作及探头工作时的发热问题。然后进行以下实验:一、LIPUS联合牙周翻瓣术对Beagle犬慢性牙周炎组织修复作用的初步研究4只Beagle犬建立下颌前磨牙慢性牙周炎模型,在牙周翻瓣术及根面处理术控制局部炎症和改善根面相容性的基础上,将LIPUS(频率1.5MHz、波宽200μs、重复率1KHz)以不同强度(30、60mW/cm~2)和不同处理时间(20min/d、20min/2d)分为四个LIPUS处理组(①ISATA30mW/cm~2 *20min/d组、②ISATA30mW/cm~2*20min/2d组、③ISATA60mW/cm2*20min/d组、④ISATA60mW/cm2*20min/2d组)辐照Beagle犬慢性牙周炎组织,对照组行翻瓣及根面处理术。6周后发现Beagle犬牙周炎组织炎症减轻;LIPUS处理前后影像学表现变化不明显;LIPUS处理前后牙龈组织温度平均波动在1°C内。组织学切片分析显示各LIPUS处理组新生牙槽骨中骨胶原成熟程度较对照组高,但组间主观判断差别不明显;ISATA30mW/cm2* 20min/d组成骨细胞增生较其他组明显;各组均有长结合上皮愈合。活体荧光标记提示LIPUS处理组新骨形成活跃度较对照组高。该实验结果提示:一定参数的LIPUS(频率1.5MHz、波宽200μs、重复率1KHz、ISATA30或60mW/cm2、处理时间20min/d或20min/2d)对牙周炎组织的修复可能具有潜在的促进作用,尤其在促进牙槽骨成熟方面;ISATA30mW/cm2 *20min/d的LIPUS处理方式可能对牙周成骨细胞具有较好的生物效应,需进一步研究。此外,本研究发现牙龈上皮生长速度快于牙周膜细胞,并出现长结合上皮愈合,要获得更好的牙周组织修复效应可能需要限制生长速度快于牙周膜细胞的牙龈上皮细胞和结缔组织优先接触根面。二、LIPUS联合引导组织再生术对Beagle犬牙周骨缺损组织修复的初步研究在测量不同厚度ePTFE膜超声穿透率的基础上,遴选了LIPUS衰减率达10-15%左右的ePTFE超声透声膜。5只Beagle犬建立牙周骨质缺损模型,设立:①LIPUS(强度60mW/cm2、频率1.5MHz、波宽200μs、重复率1KHz、处理时间20min/d)和GTR联合组、②LIPUS处理组、③GTR组和④空白对照组。4周后“牙体-牙周”联合标本观察发现新生组织完全充填原牙周骨缺损处,探软;各组间牙龈组织温度变化不大。组织学切片发现牙周组织缺损处由新生骨组织和结缔组织充填;LIPUS和GTR联合组新生牙周组织在量上和成熟度上优于其他组;GTR组新生牙骨质、牙槽骨较对照组多但成熟度不如LIPUS处理组;对照组新生骨胶原相对少而成熟度不高。该实验发现LIPUS联合引导组织再生术,牙周组织的新生量和牙槽骨成熟度上更优于其他组,LIPUS对新生骨成熟有一定促进效应。这提示将LIPUS与GTR等组织再生手段结合,具有潜在的促进牙周组织的修复效应。不过牙周组织再生膜可导致一定超声能量的衰减,因此LIPUS与GTR联合时需相应调整参数。综上所述,本研究发现一定参数的LIPUS在一定程度上可加快钙盐沉积,促进新生骨质结构的改建和成熟,缩短牙周组织修复时间,且LIPUS联合GTR可能具有更好的修复效应。本实验为进一步遴选合适的LIPUS参数辅助现有牙周组织治疗提供借鉴,但LIPUS促牙周组织的具体改建机制仍有待于进一步研究。更多还原

【Abstract】 Low Intensity Pulsed Ultrasound, a secure and non-invasive therapeutic method, can promote the repair process of bone and soft tissue. Periodontal disease is the chronic inflammation of periodontium, and the key to treatment is rebuilding the structure and function of periodontal tissue.Based on the periodontal tissue regeneration theory and the biological effects of LIPUS, the study of the effect of LIPUS combined with periodontal flap surgery or guided tissue regeneration on the periodontium repair in Beagle dogs was preliminarily conducted, which may provide a adjuvant therapy of the periodontal disease by LIPUS in future.At first, LIPUS transducer morphous and fixation was reformed on the base of preliminary studies, which can avoid the artificial error and blind operation in transducer fixation, avoid thermogenesis when it works.Then,two studies were performed:1. Preliminary study of the effect of LIPUS combined with periodontal flap surgery on the chronic periodontitis repair in Beagle dogsChronic periodontitis models in mandibular premolars were eatablished in 4 Beagle dogs. After inflammation control and root surface compatibility improvement with periodontal flap surgery and root conditioning, LIPUS was conducted on the periodontitis tissue in Beagle dogs, 4 LIPUS (parameter of frequency 1.5MHz, pulsed width 200μs, repeated frequency 1kHz) groups were divided as①ISATA30mW/cm2 *20min/d group,②ISATA30mW/cm2*20min/2d group,③ISATA60mW/cm2 *20min/d group,④ISATA60mW/cm2*20min/2d group, one control group designed with flap and root conditioning treatment at the same time.6 weeks later, the inflammation of the periodontitis tissue was relieved. After LIPUS treatment no significant changes were observed with X-ray examination; and the average temperature fluctuation of the gingival tissue was below 1°C. Histological analysis indicated that the neogenetic alveolar bone in LIPUS groups was more mature than that in the control group, but no significant difference was founded in the 4 LIPUS groups; the osteoblasts were more active in ISATA30mW/cm2 *20min/d group than in other groups; long-junction epithelium was founded in each group. Fluorescent markers in vivo indicated that the neogenetic alveolar bone formation in LIPUS groups was more active than in control group.All results indicated that LIPUS with certain parameters (frequency 1.5MHz, pulsed width 200μs, repeated frequency 1kHz, ISATA30mW/cm2 or 60 mW/cm2, exposure time 20min/d or 20min/2d) may have some repairtive effects on the periodontitis tissue,especially the alveolar bone; parameters of ISATA30mW/cm2 and exposure time 20min/d may have better effects on osteoblast, which needs further study.In addition, gingival epithelium cell grows quicker than periodontal ligament cell, as a result, long-junction epthilium was founded in each group, which suggests attachment of the gingival epithelium cell and the connective tissue to root surface should be confined to received better repairtive results in periodontal tissue.2. Preliminary study of the effect of LIPUS combined with guided tissue regeneration in periodontal bone defects repair in Beagle dogs.After measuring the LIPUS penetration rates of several ePTFE membranes in different thickness, the LIPUS-penetrative ePTFE membrane which can only attenuate 10-15% LIPUS energy was chosed.Periodontal bone defect model were established in 5 Beagle dogs. LIPUS(ISATA60mW/cm2 *20min/d, freqency 1.5MHz, pulsed width 200μs, repeaded frequency 1KHz, exposure time 20min/d)was applied in the study, and 4 groups of①GTR和LIPUS combination group,②LIPUS group,③GTR group and④control group were designed.4 weeks later, the“tooth-periodontium”specimens revealed that the defects were flood with neogenetic tissue; the gingival temperature had no significant change after LIPUS treatment. Histological analysis indicated that the periodontal bone defects were flooded with neogenetic bone and connective tissue; the neogenetic periodontal tissue was more in quantity and more mature in GTR and LIPUS combination group; the quantity of neogenetic cementum and alveolar bone was more in GTR group than in control group, while the maturation of the neogenetic bone was inferior to LIPUS group; the quantity of neogenetic bone was less and the maturation was inferior in control group.The result suggested that combination of LIPUS and guided tissue regeneration can have better results on periodontal tissue repair and neogenetic bone maturation, LIPUS may have some potential on the bone maturation. The combination of LIPUS and tissue regeneration method as guided tissue regeneration may have some potential to promote the rapair of the periodontal tissue, while the membrane can attenuate some of the ultrasound engergy, the LIPUS parameters should be adjusted when used with GTR. In conclusion, LIPUS with some parameter may have some effects on calcium deposition, neogenetic bone rebuilding and maturation to shorten the periodontal tissue repair process, which may be better when combined with guided tissue regeneration. Although this study provides some reference to suitable LIPUS parameters for the adjuvant therapy of periodontal disease, the mechanism of LIPUS in the repair of periodontal tissue should be further studied.更多还原