Effect of Radiotherapy on Cariogenic Organism Streptococcus sobrinus in Saliva in Head and Neck Cancer: A Clinical Study.

AIM: Aim of the study was to assess salivary Streptococcus sobrinus in head and neck cancer using quantitative polymerase chain reaction (PCR).

MATERIALS AND METHODS: Unstimulated saliva samples were collected from head and neck cancer patient preradiotherapy. Unstimulated saliva samples were collected from oral and laryngeal cancer patients after 6 weeks of radiotherapy (dose 60 Gy). The subjects were explained not to consume solids or liquids or carry out any dental hygiene activity 1 hour prior to saliva collection. Accumulated unstimulated saliva was collected in cylindrical tube through funnel. The collected saliva was then transferred to Eppendorf tube containing Tris-ethylenediamine-tetraacetic acid (EDTA) (TE) buffer and was transported to lab for real-time PCR analysis.

RESULTS: Streptococcus sobrinus significantly increased post-radiotherapy as compared with preradiotherapy in head and neck cancer patients.

CONCLUSION: Within the limitation of this study, we conclude that amount of S. sobrinus increases postradiotherapy in head and neck cancer patients.

CLINICAL SIGNIFICANCE: As radiation therapy has harmful effects on hard and soft tissues of oral cavity, dentists should provide motivation for oral health care to the patients.