cavities and pregnancy

Do cavities actually cause preterm labor? I've had one since before I was pregnant that my dentist said he wanted to monitor and it's been 6 months since I have seen him. I honestly hate going to the dentist and hate getting fillings so I'm worried about having to go. My tooth doesn't bother me but I also don't want something happening to my baby. There are so many do's and dont's with pregnancy and I wanted to know how serious this is. Thanks