Two front teeth on backside (not visible) have a small chip. My dentist recommends bonding.

How did you get the chip in the first place?  Do you know or is it something you just noticed one day? Do you clench or grind your teeth.  It may be a bite related issue.  All these factors need to be considered before deciding on fixing it or not.  If you do the bonding without addressing the factors then the bonding may not last. Find a dentist that understands bite related problems.  You can Google Pankey and find a dentist in your area that is trained in these types of issue. Hope that helps.  Good Luck!  

Like other doctors have mentioned, it is important to understand and find the root cause of these issues so that you have a good long-term prognosis on whatever treatment you have done. When teeth are chipped, exposing the softer part of your tooth (dentin) you are more susceptible to decay and damage - so from a perspective of protecting your teeth from further damage, it is beneficial. 

Many times the edges of front teeth begin to wear and chip from behind. It is best to restore and protect this from progressing. Bonding these worn areas slows this down as well.

Hello,When you have a teeth with a small chip, is good to take care of it. Once you got a chip on a teeth, it can get bigger by the time as  futher damage. I hope it help you. Good luck!. 

Ideally you would have these areas of chipping bonded.  Practically it makes little difference.  The bigger question would be, "Why are the teeth chipping?"  Chipping of front teeth is often related to chewing patterns. This can sound quite complicated, but to a dentist who really understands function of jaws (called "Occlusion") it would make perfect sense.  To be more specific, when we chew our lower teeth trace out an eliptical motion.  If the teeth fall within this eclipse, they will invariably chip; so the better solution would be to orthodontically tip the edges of these teeth out of the chewing pattern.