VPN or Virtual Private Network is a good way to create a relatively secure system for the dentist and dental team members to access the office from home via a remote log on. This allows for telecommuting which has many advantages. As dentists we eventually actually have to be in the office with an assistant to actually do the dental work however it is surprising how many administrative tasks can be done remotely once you give it a try.
The linked article talks about VPNs in general terms and makes some suggestions for various options.
VPN traditionally has been a locally-deployed client/server solution. You would build a VPN server to manage and negotiate the connections and install clients to the machines that needed remote access.