Detection and comparison of spirochetes in periodontal health and disease by microscopy and polymerase chain reaction techniques: A microbiological study

Background: Periodontitis is caused by specific microorganisms or group of specific microorganisms. Spirochetes have been implicated to play a role in the pathogenesis of the periodontal disease. Objectives: The aim is to detect the prevalence of total spirochetes in patients with healthy periodontium, gingivitis, and periodontitis using microscopy and polymerase chain reaction (PCR) techniques. And to compare microscopy (silver nitrate staining) technique and PCR technique in the detection of spirochetes. Subjects and Methods: A total of 150 patients were selected and divided into healthy, gingivitis, and periodontitis groups with 50 patients in each group. Subgingival plaque samples were collected using sterile Gracey curettes. The plaque samples were analyzed for the presence of spirochetes using microscopy and PCR techniques. Statistical analysis for the prevalence of spirochetes was performed using the Chi-square test. The sensitivity and specificity of the microscopy and PCR techniques were compared. Results: The prevalence of spirochetes increased from healthy to gingivitis to periodontitis patients. The prevalence of spirochetes was statistically significantly higher in the periodontitis group as compared to the healthy and gingivitis group. PCR was more sensitive in detecting spirochetes than microscopy, but that microscopy showed slightly greater specificity than PCR. Conclusion: There is a strong association between the presence of spirochetes with periodontal disease as well as its severity. The microscopic method by silver nitrate staining can be a very useful, simple, and rapid screening method for the evaluation of oral spirochetes, but PCR technique may serve as more sensitive indicator of subjects at risk for periodontal disease, thus allowing preventive measures.