The Buildup of Tartar (really calculus but if I mention it people think I am going to talk about Descartes and math. Which is probably slightly more boring than Dentistry) on the back of the lower front teeth are due to a combination of factors. First there is a Salivary duct under the tongue that does nothing but squirt saliva on the backs of these teeth Then there is gravity which allows the saliva to pool on the floor of the mouth. Last but not least it is hard to reach with a toothbrush, manual or electric. Enter the Sulcabrush. It will clean the back of the bottom teeth like a charm. A couple of passes in the morning and you are set! It will make the cleaning at the dentist so much easier because you are keeping it off instead of once, twice a year.