What does "brightened" mean?
I am using the word "brightened" to mean you have a less than normal amount of tooth decay. You may want to check out this article which explains this difference between tooth decay and tooth decay that is caused by lack of nutrition.
There are many reasons why you may have tooth decay, and not be bright. If you have a tooth that is not bright, it is possible that your teeth have a lot of mineral in them which is causing a lack of light. The minerals may build up inside your tooth, causing the tooth to be dark. This means that the light from the sun and light from the candle are not coming in. You may be wondering why your teeth aren't bright. That is because the teeth of a dark person are made up of less calcium (more calcium causes bright teeth), more vitamin C (more vitamin C causes dark teeth), more fluoride (more fluoride causes black eyes), and more salt (salt will cause blue eyes).
The most common cause of a lack of light in a tooth is an issue with the enamel. If a tooth has too much calcium, it will have too much phosphate. When this happens, the tooth will not shine because it will not have enough light.