You may use an exemption certificate if, as a purchaser: 1  you intend to resell the property or service; 2  you intend to use the property or service for a purpose that is exempt from sales tax; or. 3  you make purchases as an agent or employee of tax-exempt nonprofit organizations or government entities.
Brush your teeth at least a couple of times a day, once in the morning and most especially before bed. And it is just as important to clean between teeth by using dental floss or an oral irrigator. If you have questions, ask your dentist or hygienist about when would be the best time for you to brush.
When you brush is just one factor in keeping your teeth healthy. If you are going to pick only one I would lean towards brushing at night. -Salivary flow is lowest while sleeping. Saliva provides a buffer against acids produced by bacteria (in addition to many other beneficial things that it does).