Analysis Of Dental Plaque Bacteria Associated With Caries In Aged People With Type 2 Diabetes

Background: Diabetes mellitus is a generalized metabolic disorder, characterized by hyperglycemia. Type 2 diabetes is the most common type of diabetes in aged people. It is suggested that diabetes is often associated with vascular disease, impaired immune system, and changed salivary property. Studies have approved the association between periodontal disease and diabetes. However, research reports which sought to clarify the association between dental caries and diabetes presented conflicting results. Several studies have demonstrated that factors related to diabetic, such as metabolic control, past caries experience, oral hygiene, dental self-efficacy, saliva, counts of streptococci mutans, lactobacilli, and yeast in saliva, may influence the caries process. Dental plaque is recognized as playing a major role in the etiology of caries. At present, very few details have been reported on the microbial diversity of the dental plaque in diabetic individuals related to caries.Objective: The aim of this study was: to quantify the cariogenic bacteria of dental plaque in the diabetic elders, compared with the healthy; to analyze the association between dental plaque bacteria and diabetic factors; to evaluate the caries risk of diabetic elders according to pathogenesis. Methods: The study comprised randomly sampled 82 type 2 diabetic aged inpatients from West China Hospital of Sichuan University (diabetic group), 82 age- and gender-matched healthy aged people (control group). Clinical examinations were performed, and DMFT, DI-S index was recorded. 20 subjects were sampled from each group. Saliva was tested for unstimulated flow rate (SF) and glucose concentration (SG). Dental plaque was collected for quantification of streptococcus mutans, lactobacillus, actinomyces absolutely and relatively, by TaqMan real-time PCR assay.Results: There were no significant differences in DMFT and SF between the diabetic and control group (P>0.05). The diabetic group had statistically higher DI-S index and SG than the control (P<0.05). The number of streptococcus mutans of dental plaque was higher in the diabetics than the control (P<0.05), and positively associated with SG. The percentage of this organism was positively associated with SG and GHbA)_1c.There was no significant difference between the diabetic and control group in lactobacillus quantity (P>0.05). Negative correlation was found between the number of lactobacillus and SG, also between the percentage of lactobacillus and SF. The diabetic had a little higher amounts of actinomyces than the control (P>0.05).Conclusion: The amounts of streptococcus mutans and actinomyces of dental plaque increase and the risk of caries, especially root caries increases in type 2 diabetic elder. It should be taken into account to guide and improve the aged diabetic patients' general and oral health.