Hello, this is Shiba Koen / Mita SACHI Dental Clinic. 🦷

Have you ever experienced a tooth that was supposed to have finished treatment in the past developing a cavity again without you noticing?
This is called “secondary caries” (recurrent cavities), and it refers to a condition where a cavity develops again around the fillings or crowns that were previously placed during treatment. In fact, it is said that many cavity treatments for adults are due to these secondary caries.

Why do treated teeth develop cavities again?

1. Deterioration of fillings and crowns over time

The inside of the mouth is a harsh environment where cold and hot things enter and biting force is constantly applied. When fillings and crowns gradually deteriorate over years of use, microscopic gaps can form between them and your own teeth. When bacteria enter those gaps, cavities tend to progress from the inside. In particular, silver teeth and resin (plastic) used in insurance-covered treatments are prone to deterioration and deformation over the years due to the characteristics of the materials, and plaque also tends to adhere to them easily.

2. Missed spots during self-care

The boundary (step) between the filling or crown and the tooth is a point where dirt inevitably tends to accumulate. If plaque remains, cavity-causing bacteria produce acid, which dissolves the tooth again.

3. Decrease in saliva, or teeth grinding and clenching

Saliva has an important self-cleaning action that washes away dirt in the mouth and protects the teeth. When the amount of saliva secretion decreases due to stress, aging, or the effects of medication, the risk of cavities increases. Additionally, the strong load from unconscious teeth grinding or clenching can cause damage to fillings or create gaps.

Be careful of these signs

* Sensitivity to cold or sweet things
* Pain or discomfort when biting
* Fillings or crowns have come off, or feel like they are floating
* The teeth around the filling have turned blackish

A characteristic of early secondary caries is that subjective symptoms such as pain are unlikely to appear. Caution is required because they have often progressed by the time you notice them.

To protect your precious teeth from secondary caries

  • In addition to careful daily brushing, make flossing and using interdental brushes a habit.
  • Use fluoride-containing toothpaste or gel to strengthen the tooth structure.
  • Review habits such as excessive intake of sweets or snacking throughout the day.
  • Receive regular checkups and professional cleanings.

In the unlikely event that you develop secondary caries, we will perform treatment to carefully remove the cavity and replace it with a new filling or crown. If it has progressed and reached the nerve, root canal treatment may be necessary.

Many people feel relieved, thinking, “Since this tooth was treated once, it’s fine now.” However, treatment is only a “restoration,” and as long as it is an artificial object, it is difficult to maintain the same condition forever.
That is why correct daily self-care and regular maintenance at a dental clinic lead to the best prevention and early detection.
To continue protecting your original beautiful teeth for a long time, please come in for a regular checkup. ✨