OLDWICK, N.J.--(BUSINESS WIRE)--A.M. Best has revised the outlook to positive from stable and affirmed the financial strength rating (FSR) of A- (Excellent) and the issuer credit ratings (ICR) of “a-” of Delta Dental of California (DDC) (San Francisco, CA) and its affiliate, Delta Dental Insurance Company (DDIC) (Wilmington, DE). Concurrently, A.M. Best has revised the outlook to positive from stable and affirmed the ICRs of “bbb” of Delta Dental of Pennsylvania (DDP) (Mechanicsburg, PA) and it