Maybe I missed something or misunderstood.. Has your friend been diagnosed with diabetes in the past? Because those numbers aren't even close to diabetic range. A fasting sugar of 99 or below is normal - 100-115 is pre-diabetes not diabetes. If she has been diagnosed in the past, those numbers would be considered well-controlled and if she's not on meds for it would qualify as in remission. There are a lot of things that can cause bad teeth, and if she hasn't been given a diabetes diagnosis by a doctor, I would be very skeptical of a dentist who keeps mentioning that. Her numbers are will below the threshold for "well-controlled diabetes." And other than her fasting sugar not even close to pre-diabetes levels. 100 is only one point out of the normal range. That's excellent if she is diabetic. Congratulations to her on getting it that well controlled if she does have it.