高压氧疗法对大鼠心理应激条件下的牙周炎治疗效果观察

目的:探讨心理应激对大鼠实验性牙周炎的影响,观察高压氧(hyperbaric oxygen,HBO)治疗对心理应激相关牙周炎的疗效。方法:清洁级4周龄雄性Wistar大鼠80只,随机分为4组:(1)正常对照组;(2)牙周炎组:用浸有牙龈卟啉单胞菌株的丝线结扎左侧上颌第2磨牙牙颈部,复制实验性牙周炎模型;(3)单纯应激组;(4)牙周炎+应激组。于实验后第9周停止应激刺激,对除正常对照组外其它各组大鼠每组选取4只进行HBO治疗。于实验后2、4和8周末分批处死动物,每组处死4只,于实验后10周末处死动物,每组处死8只。采血检测血糖浓度、血浆促肾上腺皮质激素(ACTH)、皮质类固醇和肾上腺素含量。测量术区的牙周附着情况,制作牙体牙周联合切片,观察牙周的组织学改变。结果:检测应激标记物的变化可见单纯应激组的血糖及血浆ACTH、皮质类固醇和肾上腺素含量在实验后第2、4周明显高于正常对照组和牙周炎组(P0.01),第8周时血糖降至正常水平,但血浆ACTH、皮质类固醇和肾上腺素含量仍高于正常对照组和牙周炎组(P0.05);牙周炎+应激组在实验后第2、4和8周血糖及血浆ACTH、皮质类固醇和肾上腺素含量均高于正常对照组和牙周炎组(P0.05);HBO治疗组牙周炎+应激组血糖明显低于非治疗组(P0.01),单纯应激组和牙周炎+应激组血浆ACTH、皮质类固醇和肾上腺素水平显著下降(P0.01)。大体观察可见正常对照组及单纯应激组牙周附着位置正常;牙周炎组出现牙龈萎缩,附着丧失明显;牙周炎+应激组附着丧失明显,根分叉暴露,HBO治疗后,牙龈水肿减轻,牙周袋变浅。单纯应激组与正常对照组在各时点的牙周附着水平的差异不显著(P0.05);牙周炎+应激组附着丧失程度在各时点均明显高于牙周炎组(P0.01);HBO治疗结束后牙周炎组及牙周炎+应激组牙周附着丧失程度减轻(P0.01)。组织学观察可见牙周炎+应激组牙周组织破坏程度在各时点均重于牙周炎组;经HBO治疗后,牙周组织炎症程度减轻,炎症细胞浸润减少。结论:心理应激可加重牙周炎进程。HBO对大鼠实验性牙周炎及心理应激相关牙周炎均有治疗效果。

Effect of hyperbaric oxygen on periodontitis with psychological stress in rats

AIM: To investigate the role of chronic psychological stress on periodontitis and the effects of hyperbaric oxygen (HBO) on periodontitis with psychological stress in rats. METHODS: Male special pathogen-free Wistar rats (n=80) were randomly divided into 4 groups: (1)normal control group; (2)experimental periodontitis group: the periodontitis model was induced by wrapping 3/0 silk ligature inoculated with Porphyromonas gingivalis around the left maxillary second molar of the rats; (3)psychological stress stimulation group; (4)periodontitis model with stress stimulation group. Psychological stress was removed at the 9th week after ligature, and 4 rats from each experimental group were randomly chosen for HBO treatment. The rats were sacrificed at the 2nd, 4th, 8th and 10th weeks after ligature. The levels of blood glucose, adrenocorticotropic hormone (ACTH), corticosterone and adrenaline were measured as the stress markers. The histological changes of periodontal tissues were observed under microscope with HE staining. RESULTS: The levels of blood glucose, ACTH, corticosterone and adrenaline in psychological stress stimulation group and periodontitis with stress group were significantly higher than those in control group and experimental periodontitis group at the 2nd and 4th weeks after ligature (P<0.05). The levels of the stress markers were significantly lower than those in untreated groups in the 10th week after HBO (P<0.01). The sites of gingival attachment were normal in control group and psychological stress stimulation group. Periodontal pocket, and periodontal attachment loss (AL) were observed in experimental periodontitis group. The tissue damage was much heavier in periodontitis model with stress stimulation group as the furcation of tooth was exposed and the tissue damage was observed on both sides of the adjacent teeth. No significant difference of AL between psychological stress stimulation group and normal control group during the experiment was observed. The AL in periodontal model with stress stimulating group was significantly higher than that in experimental periodontitis group at the 2nd, 4th and 8th weeks (P<0.01). The level of AL was attenuated at the 10th week after HBO (P<0.01). No difference of histological change in periodontal tissues was observed between control group and psychological stress stimulation group. Severer inflammatory changes and alveolar bone destruction were observed in periodontitis with stress group than those in experimental periodontitis group. The levels of inflammation reduced at the 10th week after HBO. CONCLUSION: Stress stimulation is one of the inducing factors of periodontitis in rats, which aggravates periodontitis. HBO may represent a useful way in treating psychological stress periodontitis.