Study Of Porphyromonas Gingivalis In The Rat Gingiva Groove Liquid Under The Conditions Of Chronic Intermittent Hypoxia

Objective:This study aimed at exploring the change of Porphyromonas gingivalis(P.gingivalis)in the rat gingiva groove liquid under the conditions of chronic intermittent hypoxia by simulating the patients of the obstructive sleep apnea-hypopnea syndrome(OSAHS).Methods:32 male SD rats were randomly divided into four groups: normoxia control group(group A),normoxia periodontitis group(group B),intermittent hypoxia group(group C),and intermittent hypoxia with periodontitis(group D).Using orthodontic ligation silk to ligating bilateral maxillary second molar neck and high sugar diet method to establish model of periodontitis,the rats in normoxia and hypoxia group were raised respectively under the condition of oxygen and chronic intermittent hypoxia.After 8 weeks,All rates were examined for periodontal condition,and the clinical periodontal indicators were recorded,and gingival groove fluid of each rat maxillary second molar on the right side were collected.Then the rats were executed by air embolism,and maxillary bone were removed in order to observe absorption of alveolar bone.P gingivalis in the rat gingiva groove liquid was detected using real-time fluorescent quantitative PCR method.Results:1.After 8 weeks,experiment tooth were found that food accumulation,swollen gums,bleeding on probing and periodontal pocket formation in group B and group Drats,while in group A and group C rats had gum essentially normally.Periodontitis rat model was set up successfully.2.The clinical periodontal indicators in group D was significantly higher than other groups,the difference was statistically significant(p < 0.05);The clinical periodontal indicators in group B and C were higher than group A,the difference were statistically significant(p < 0.05).3.Alveolar bone in group D was absorpted significantly than other groups.4.P.gingivalis was detected in all groups.P.gingivalis in group D was significantly higher than other groups,the difference was statistically significant(p < 0.05);Meanwhile,P.gingivalis in group B was significantly higher than group A and C group,the difference was statistically significant(p < 0.05).There was no statistically significant differences in gingiva groove liquid P.gingivalis concentration between A group and C group.Conclusion:1.The rat model of periodontitis under chronic intermittent hypoxia was set up successfully.2.P.gingivalis was one of resident bacteria in oral gingival groove liquid.3.Chronic intermittent hypoxia could aggravate the severity of periodontitis,which was associated with the change of P.gingivalis in gingival groove liquid.