A custom fitted night guard (occlusal splint) is the best defense when it comes to grinding your teeth at night. The flexible guards you find at the drug store don't offer very much protection against grinding and clenching. You really need a rigid, solid guard for your teeth to slide on. Flexible guards are thicker and a little "chewy" - this makes your mouth think you should be chewing all night and can actually increase your grinding and clenching. A custom night guard may seem like a big investment, but it is significantly less than multiple root canals, crowns and bridge work. The fee also includes several follow-up visits for adjustments to ensure the guard fits properly. Depending on the dentist office, fees vary anywhere from $500-$1,300 - The less costly office may not include any follow-up visits for proper fitting. Be sure to find out exactly what is included when you make your decision on where to get your night guard. More often than not, you get what you pay for.