Plaintiff filed a medical malpractice claim for injuries suffered following dental surgery by the defendant. The plaintiff attempted to cure a deficiency in the opinion letter by providing an affidavit after the statute of limitations period had expired. The court held that regardless of the type of procedure a plaintiff elects to employ to cure a defect in an opinion letter filed in accordance with § 52-190a, that procedure must be initiated prior to the running of the statute of limitations.