It may b due to 1) Pocket in gingiva where food lodgement occurs, or 2) caries ,3) attrition due to vigorous brushing ,abrasion 4) calculus deposition
Next Steps
1)Apply ketorol DT locally on that tooth
2)use vantej tooth paste as per direction if tooth is attrited from above or abrade from side
3) visit clinic for scaling if bad breath or band of calculus on that tooth
4)Senquel AD mouth rinse
these are temporary relief.. need to find exact cause
Health Tips
visit dental clinic for proper diagnosis & tx