Went to dentist yesterday, no infection on x-ray. still tiny bit uncomfortable. did crown then rootcanal 9 months ago on molar. does this mean ok?

Great oral care: Good oral care, brushing and flossing go a long way in making your mouth feel great. Many times minor sensitivity can be relieve just be taking better care of your mouth. If your dentist checked your tooth and everything is ok then trust your dentist and see what great oral care will do. If you do not trust your dentist then seek a second opinion.

Probably: May just need to adjust (lighten) the bite pressure on the tooth from the opposing tooth to become 100% comfortable.

Infected vs Inflamed: It is important to understand that pain does not equal infection. Often times a tooth that has been treated with a root canal can remain tender but look 'ok' on the xray. This is because the xray will not completely show areas that could have been missed so inflammation remains. It would be best to have a consultation with an endodontist for an opinion. There is probably no emergency looming.

see endodontist: If its been 9 months and still uncomfortable can get root canal reevaluated ..As long a the dentist told the crown margins are okay..And gum health is okay..