Tooth decay occurs when acids produced by bacteria damage a tooth. Early changes may not hurt. Once a cavity develops, it may trap food, cause sensitivity or progress towards the pulp inside the tooth.
A dentist examines the tooth and may recommend an X-ray when it would help diagnosis. Early non-cavitated damage may sometimes be managed through preventive measures. A cavity may require removal of damaged tissue and a filling; more extensive damage needs a different plan.
Ask what material is proposed and why it suits the tooth’s location, remaining structure and chewing forces. A filling repairs damage but does not remove the underlying risk of future decay.
Good cleaning, fluoride use and changes to frequent sugar intake remain important after treatment. Report persistent pain or a filling that feels unusually high when you bite. Waiting until pain is severe can make treatment more complex.