Study On The Correlation Between The Ph-equilibrium Of The Oral Micro-ecological And Caries And Periodontal Disease

Oral micro-ecology is a kind of ecological environment, in which many environmental factors are constantly adjusting to keep a dynamic equilibrium. The survival ability of the bacteria in the micro-environment depends on its ability responding to the environmental change. The regulation of bacteria in the dental plaque makes the oral micro-ecological in a dynamic equilibrium to avoiding the occurrence of oral disease. The composition of urea(CO(NH2)2) in the gingival groove fluid will be hydrolyzed under the action of urease quickly into a molecule of carbon dioxide(CO2) and two molecules of ammonia(NH3). The hydrolysis equations is CO(NH2)2+H2O = CO2 + 2NH3(under urease). The alkaline material which produced by the reaction between ammonia and water, can counteract with acid produced by the fermentation of the glucose solution. Also, it can elevate the PH of the oral micro-ecological and maintain the neutral-PH environment in the plaque. In this way, the bacteria as Streptococcus Mutans can produce acidic materials to make dental decay depressed, accordingly the Ph-equilibrium will be established to prevent the enamel demineralization and promote enamel mineralization again. Therefore, the urea hydrolysis contribute to prevent dental decay.Urea enzyme(urea amidohydrolase), a kind of metal bound enzyme, exists in prokaryotes and eukaryotes. And it plays a key role in the process of urea hydrolysis, which is the essential condition of urea hydrolysis. Generally speaking,the bacteria in dental plaque such as Streptococcus, Actinomyces naeslundii,Helicobacter pylori etc, all of which have the urease activity. In this study, we focus on the actinomycetes naeslundii, and analysed DMFT(Decay Missed Filled Tooth) and CPI(Community Periodontal Index) of the patients with caries and periodontal, based on the analysis of the factors affecting the production base of actinomycetes.Objective:1. Investigate and analyses the difference of the DMFT(Decay Missed Filled Tooth) and CPI(Community periodontal Index) of patients with Caries and periodontal disease.2. Study on the PH difference in the gingival crevicular fluid of the patients with Caries and periodontal disease.3. Research On the substrate concentration and PH Influcencing Urease Activity of Actinomyces naeslundii Methods:1. The data of the patients who came from the First People’s Hospital of Jining city from August 2013 to August 2014 was selected. From which caries(DMFT ≥ 6) and periodontal(CAL acuity 2.5 mm) was selected and SPSS13.0statistical software was used for statistic processing.2. PH indicator method was used to measure and analyse the difference of the PH of the caries and periodontal disease in order to find the relationship between caries and periodontal disease.3. Cultivated actinomycetes biofilm of single bacteria using continuous chemostat model in order to detect the influencing of the Nitrogen-based material,sugar-based material and PH to urea enzyme activity.Results:1. CPI of the Caries was lower than that in periodontal disease and DMFT of periodontal disease was significantly lower than that in the Caries. The differences between two groups have significant statistical significance through which we can know there is antagonistic relations between caries and periodontal disease.2. PH in the gingival groove fluid of the caries was lower than that of the periodontal disease. PH in the gingival groove fluid of the periodontal disease was higher than that of the caries.3. The activity of the actinomycetes urea enzyme changes with the concentration of the substrate. The higher of the sugar concentration, the higher of the urea enzyme activity. The activity of urea enzyme was suppressed with the higher the concentration of nitrogen-based material. PH was also the factors influencing the activity of urease. In the case of PH 4.0, the activity of urease wasalmost completely deactivation. In the case of PH 5.0, about 40% of the normal activity can be arrived; the maximum activity of urease would reach when the PH around 6.5. After that, the urea enzyme activity would decline with the decline of PH.Conclusion:1. There are antagonistic relations between caries and periodontal disease.2. There is PH difference in the gingiva groove liquid between caries and periodontal disease.3. The concentration of the substrate and PH are important factors to influence the activity of actinomycetes naeslundii urea enzyme.