Let's All Eat Cheese

According to a study published in the May/June 2013 issue of General Dentistry, the peer-reviewed clinical journal of the Academy of General Dentistry (AGD), consuming cheese and other dairy products may help protect teeth against cavities.

The study sampled 68 subjects ranging in age from 12 to 15, and the authors looked at the dental plaque pH in the subjects' mouths before and after they consumed cheese, milk, or sugar-free yogurt. A pH level lower than 5.5 puts a person at risk for tooth erosion, which is a process that wears away the enamel.  "The higher the pH level is above 5.5, the lower the chance of developing cavities," explains Vipul Yadav, MDS, lead author of the study.

The subjects were assigned into groups randomly. Researchers instructed the first group to eat cheddar cheese, the second group to drink milk, and the third group to eat sugar-free yogurt. Each group consumed their product for three minutes and then swished with water. Researchers measured the pH level of each subject's mouth at 10, 20, and 30 minutes after consumption.

The groups who consumed milk and sugar-free yogurt experienced no changes in the pH levels in their mouths. Subjects who ate cheese, however, showed a rapid increase in pH levels at each time interval, suggesting that cheese has anti-cavity properties.

The study indicated that the rising pH levels from eating cheese may have occurred due to increased saliva production which could be caused by the action of chewing. Additionally, various compounds found in cheese may adhere to tooth enamel and help further protect teeth from acid.

"It looks like dairy does the mouth good," says AGD spokesperson Seung-Hee Rhee, DDS, FAGD. "Not only are dairy products a healthy alternative to carb- or sugar-filled snacks, they also may be considered as a preventive measure against cavities."

Why did the anesthetic not work at my dental appointment

Listed below are a few of the most common causes of local dental anesthetic failure:

1. Delivery Technique

Placement of the local anesthetic

The most common cause of not getting numb is when the dentist has missed the spot where he/she intended to deposit the local anesthetic.

Not waiting long enough for the local to work

The tooth has not been allowed enough time to go numb.

Giving the local too fast

Some local anesthesia techniques may not work as well if the local is given too quickly.

Choice of local anesthetic

Lidocaine or Septocaine with epinephrine works best for most situations. But if for some reason it does  not work for you, a different  anesthetic can be used.
If you have certain medical problems, an epinephrine-free solution might be preferred, such as Carbocaine.

Not giving enough local anesthetic

Sometimes it just takes a greater amount of local anesthetic to achieve profound numbing.

2. Anatomical Variation

Local anesthetic is usually effective if it is given in the right spot and has enough time to take effect. It works by blocking the nerve supply to the area being treated. 

However, there is huge anatomical variation between people. Some people have such an unusual anatomy that the “standard” dental injection does not work.

3.Infection/Inflammation

Local anesthetic is very pH sensitive. It requires a basic pH in which to work properly. Any time there is an area of acute infection and/or inflammation the pH drops and the environment becomes acidic, causing the anesthetic to not work well.

4.Fear/Anxitey

When a person is fearful or anxious, the local anesthetic may not work as well as when you’re relaxed. The hormones related to anxiety can prevent local anesthetic from working properly in some people. The actual neurophysiological mechanism by which stress hormones prevent the anesthetic from working properly is still unclear.

Does Teeth Whitening Harm My Enamel?

According to the American Dental Association (ADA), both over-the-counter (OTC) and whitening products you buy from the dentist are mostly safe and effective. However, the ADA recommends a dental consultation before self-treating in order to avoid making any existing problems with teeth and gums worse.

In addition, the ADA also acknowledges that whitening agents can cause irritation to the gums and tooth and sensitivity which usually goes away shortly after treatment ends.

Another consideration before whitening is whether or not your teeth will respond to whitening strips or another method of bleaching. Dentists can look at tooth discoloration and recommend the best whitening method. Gray and brown tinged teeth won't respond well, and sometimes not at all, to whitening strips, while yellow-stained tooth surfaces likely will improve with bleaching

One other important consideration is how well consumers follow the application recommendations and instructions when using whitening strips. If applied incorrectly or pushed into the gums, extreme sensitivity and soreness may result. Using the strips too often and for too long also can damage tooth enamel and lead to underlying tissue damage below the gums.

Some dentists report that individuals can overuse whitening products  When used in excess, however, teeth can become porous and enamel can break down.  Teeth can even become almost translucent rather than white, so heeding the recommendations of a dentist and the instructions for the product is advisable.