What is causing my teeth ache to ache a couple days after having them filled with composite?

Bite, nerve?: The bite could be high and the tooth becomes sore from the constant premature contact or the nerve inside the tooth is inflamed or something else. Call your dentist for advice and whether or not you need to be seen back to for an evaluation.

Many reasons: Your bite may be off not on biting down but in side to side movements (excursions) as well. Deep decay close to the nerve. Error in placing the filling: sloppy technique, moisture contamination, blood contamination, not using adhesive properly, creating stress in the filling during placement. Composite fillings are very technique sensitive. Pain can also be from injection.