That doesn't look unusual or immediately harmful, but it's probably good to remove the buildup if you can. Probably the best way to go is to offer some hard shelled bugs now and then. Superworm beetles, dubia roaches, etc. can act as an abrasive as they are chewed up and that is likely to be beneficial for tooth and gum health. It's good to have some MaxiGuard gel on hand that can be used as an oral cleanser, but I really don't resort to using that unless there is a wound or other obvious buildup that should be addressed. That just consists of putting a bit on a q-tip and rubbing it along the teeth and gums. They don't tend to like having that done though, so I don't consider it part of a regular routine.