Dental HMO plans are normally a more affordable dental care insurance plan then your PPO dental insurance plans. They also have few limitations the many PPO plans. However one limitation that dental HMO plans come with is that there is no out side dental network. Under a dental HMO plan you have to choose a dentist that in the plan network of dental providers. So if trying to stay with a current dentist make sure you know a head of time if they are providers of any HMO dental insurance plans.