A good brushing before bed will help protect your teeth from the buildup of plaque that leads to tooth decay. Select a brush that has soft bristles and is dentist-approved. Brush gently back and forth at a 45-degree angle to the gums. Dentists are now finding that certain people are genetically predisposed to be at a greater risk for developing dental and gum diseases. Patients who are not at an especially high risk are fine to wait until bedtime to brush, but patients who are at a higher risk should brush after dinner and before bed, as well.