Hello dear,             Hope you are doing good. Generally our tooth has minor movements and that is completely normal. Pushing your teeth with tongue intentionally or as a habit may lead to flaring up of the front teeth. If you feel like you are doing it subconsciously, please be careful and try to avoid the habit. Otherwise pushing of teeth by tongue is not that much forceful and this will not definitely cause death of the tooth.

Hello dear Please be advised See tongue had proven to provide movements to teeth by either tongue thrusting or thumb sucking Death of tooth can't occurs. However for further details you can consult me Thanks

Yes movement of teeth due to tongue is possible provided that the force is greater which happens most of the time when patient has macroglossia. But don't worry Moving your tooth with tongue won't lead to the death of the teeth (necrosis of pulp)