Cavities form when acid produced by bacteria dissolves the protective enamel layer of the tooth resulting in a hole in the structure of the tooth. The mouth has more than 6 BILLION bacteria! These bacteria eat the same foods we do. If the diet is higher in carbohydrates (sugars), the bacteria will digest the sugar and will produce the byproduct of acid. The acid will gradually dissolve the tooth structure if the teeth aren’t kept clean of bacteria, and a proper diet.
Saliva produced by the salivary glands work to buffer the saliva, and protect the teeth. Saliva neutralizes the acid, and protectively bathes the tooth. There are some conditions that will affect the quality of the saliva. Conditions that may reduce salivary flow or change the protective effect of the saliva include:
- Radiation therapy
- Sjogren’s syndrome
- Rheumatoid arthritis
- Side effects of medications
Acidic conditions of the mouth will increase the likelihood of cavities. This can occur as a result of gastro-esophageal reflux, bulimia, or sucking on lemons.
Techniques to reduce likelihood of tooth decay:
- Eat low sugar, high fiber foods
- Snack on yogurt and cheese
- Chewing on sugar-free gum after meals (naturally increases salivary production)
- Brush teeth after meals (don’t brush immediately after eating acidic or sour-tasting foods; wait 30 minutes)
- Floss nightly
- Application of sealants on teeth with deep pits and fissures
- Use high fluoride toothpaste before bedtime
The decision to fill a cavity vs. monitoring it or treat it with fluoride depends upon the extent of the cavity. Is it still within the enamel? Did it go deeper into the tooth to the dentin layer? If the caries (decay) goes into the dentin, it will have to be filled because the dentin is eight times softer than enamel, and the destruction of the tooth structure will happen much faster once the invasion of the dentin has occurred.
Pain and Cavities
Cavities usually do not hurt. In the early (incipient caries) stages, they will be completely asymptomatic. In the moderate stages (dentinal), one may experience cold sensitivity, or sweet sensitivity. The sensitivity usually lasts seconds.
Only when the destruction of the tooth structure has approached the nerve will the tooth actually start to feel symptomatic and uncomfortable. Ideally, the restoration of the tooth should occur in the early-moderate stage.
If the tooth is sensitive to hot, or has lingering pain (more than 15 seconds), it is an indication that the nerve is infected. This tooth will likely need root canal therapy (RCT).