Tooth cleaning is the removal of dental plague and tartar to prevent cavities, gingivitis and gum disease.
It is not likely that the enamel of the teeth could be scratched in the process of tooth cleaning. Enamel is one of the hardest natural substances known, second only to diamond. It is also unlikely that the cleaning process caused horizontal motions across the face of the front teeth that would result in damage. Most cleaning procedure involves a rotating instrument which would rest in a circular pattern.
Tooth sensitivity is tooth discomfort after eating cold or hot foods or liquids or even breathing cold air. This problem often happens when gums recede. The gum tissue acts like a protective blanket to cover the roots of the teeth. As the gums recede the underlying tooth roots are exposed. They are not covered by hard enamel. Thousands of tiny dentinal tubules (channels) leading to the tooth’s nerve center (pulp) are than exposed. These tubules allow more stimuli like heat, cold or pressure to reach the nerve in the tooth you feel the pain.
Poor oral hygiene which leads to plaque hardens into tartar. The bacteria that live in plaque cause gum disease and recession if nor removed can lead to tooth loss.
Hence tooth cleaning is a procedure which removes this bacteria and upon removal the tooth roots are visible which is sensitive (remember sensitivity is not produced by the procedure but rather by your germs)
Overly vigorous or incorrectly performed brushing or flossing may result in injury to the gingival (gums).