Can teeth cleaning remove black lines caused by tooth decay?

If a black line on the tooth caused by dental caries has already led to structural damage, it cannot be removed by teeth cleaning. However, if it is merely surface pigmentation or early-stage caries without tissue loss, the appearance may partially improve with professional cleaning. Seek prompt medical attention if any dental abnormalities occur.

When the black line indicates that bacteria have eroded the tooth structure and formed a cavity, the lesion has typically penetrated deep into the enamel or even the dentin. Teeth cleaning primarily removes tartar and dental plaque from the tooth surfaces and gingival crevices, but cannot repair damaged tooth structure. Therefore, such black lines cannot be eliminated through cleaning alone. Professional treatment by a dentist—such as removing decayed tissue with specialized instruments followed by filling—is required.

If the black line results from a mixture of surface stains and early carious spots without structural damage, high-frequency ultrasonic vibrations during teeth cleaning may remove some surface pigments and superficial plaque, lightening or eliminating the discoloration. However, if early decay is already present, cleaning alone is insufficient for complete treatment. Additional preventive measures such as fluoride application are needed to stop progression of the decay.

Maintain good oral hygiene by brushing teeth twice daily, rinsing after meals, using fluoride toothpaste, and scheduling regular cleanings. If a black line appears on a tooth, consult a dentist promptly to determine its cause and prevent worsening decay. Additionally, reduce sugar intake to lower the risk of developing cavities.