The main differences between MetLife and Delta Dental insurance are: Networks - Delta has larger national networks. MetLife still provides access to over 100,000 dentists. Plan types - Delta offers both PPO and HMO. MetLife has PPO plans. Brand recognition - More dentists are familiar with Delta Dental. Waiting periods - Delta waives waiting periods while MetLife may impose them. Maximum rollover - Only Delta carries over part of your unused annual maximum. Premiums - Delta tends to have slightly lower monthly premium costs. Both are reputable insurers that provide quality dental benefits at affordable rates.