As commitment is at the core of relationship programs, the latter should share similarities with prevention programs, which are key to the health sector. A field study with a dental network show that anxiety toward illness and trust toward the practitioner are key determinants to commitment to a prevention protocol. In addition, psychological reactance and relationship proneness are shown as antecedents of the commitment predictors. While reactant people may not commit to prevention programs, relational type of persons are keen to accept recommendations from the practitioner. Anxiety toward illness is viewed as an intermediate variable.