Salivary detection of periodontopathic bacteria and periodontal health status in dental students.

OBJECTIVE: Saliva may become a potential source of contamination through vertical and horizontal transmissions as well as cross-infections. This study aims to use saliva as a screening tool to detect putative periodontal pathogens in a young population with fairly good oral hygiene.
MATERIALS AND METHODS: Stimulated saliva samples were obtained from 134 dental students (20.5+/-1 years, range 18-22 years). Among those, 77 subjects also completed a periodontal examination including attachment loss, modified dental, gingival and plaque indices (AL, mDI, GI and PI). The test bacteria were identified using a 16S rRNA-based PCR detection method.
RESULTS: One or more of the test bacteria was found in 67% of the subjects. Prevotella nigrescens was detected as single bacterium in 16% of the subjects followed by Treponema denticola (4%), Porphyromonas gingivalis (2%), Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans (1%) and Tannerella forsythia (1%). Two or more pathogens were detected in 42% of the subjects. Clinical examination revealed health with no attachment loss (AL) in 84% of the students. In no AL group, 38% of the students were pathogen free while this was 25% for students in localized AL group (p>0.05). There was a statistically significant association between the detection of salivary periodontal pathogen in general and higher PI (p=0.018) and GI (p=0.043).
CONCLUSION: Within the limits of this study, it is possible to detect all six periodontal pathogens in the saliva of dental students. Although a correlation can be observed between the presence of salivary periodontal pathogen and clinical signs of inflammation such as plaque accumulation and gingival bleeding, detection of specific bacteria in saliva is not related to the presence of localized AL based on the presented study population.