OLDWICK, N.J.–(BUSINESS WIRE)–A.M. Best has affirmed the Financial Strength Rating (FSR) of A- (Excellent) and the Long-Term Issuer Credit Rating (Long-Term ICR) of “a-” of the dental HMO entities acquired by Sun Life Financial Inc. (Sun Life) as part of their 2016 acquisition of the U.S. employee benefits business of Assurant, Inc. (Assurant). The outlook of these Credit Ratings (ratings) remains stable. A.M. Best has withdrawn the ratings at the request of the company to no longer participa