Hi ... Plaque has covered your teeth . and due to it your gums start receding and this lead to root exposure .roots have nerve endings .so when dentist removes plaque these ending get expose and thus on eating cold food you have sensitivity.but it will be temporary .. Use R A thermoseal apply on sensitive area with fingure tip keep for 5 min and then do gargel . and don't drink water for 1 hr ...try this ... Hope you will be benefited ...

Thanks for your query, I have gone through your query. Usually teeth will be covered with the deposits and once you get your teeth cleaned the dentin will be exposed to oral cavity since the gums recede in gum infection. once the gums return to normal position then the sensitivity comes down. but since you are telling restoration has been fallen, the pain could be because of the secondary decay involving pulp. The pain is not because of the dentist. consult a oral physician and get a radiograph done. if the decay is involving pulp then it has to be treated with root canal treatment. if it is not involving pulp then normal filling can be done. i hope my answer will be helpful. take care.

Thanks for your query, I have gone through your query. Usually teeth will be covered with the deposits and once you get your teeth cleaned the dentin will be exposed to oral cavity since the gums recede in gum infection. once the gums return to normal position then the sensitivity comes down. but since you are telling restoration has been fallen, the pain could be because of the secondary decay involving pulp. The pain is not because of the dentist. consult a oral physician and get a radiograph done. if the decay is involving pulp then it has to be treated with root canal treatment. if it is not involving pulp then normal filling can be done. i hope my answer will be helpful. take care.