Analog: Usually called dial-up. Using a dial up connection at this time is roughly equivalent to taking a horse and buggy onto the Interstate.
ISDN: Integrated services digital network (ISDN) is a method of increasing the data speed over phone lines to roughly twice the speed of regular dial up.
DSL: Digital subscriber line is an always on not a dial up. It runs over existing phone lines and has a data transfer rate over 100 times faster than dial up.
Cable: An Internet connection that is designed to operate over cable TV lines, a cable modem can achieve extremely fast data access rates.
Wireless: Instead of using telephone or cable networks for your Internet connection, you use radio frequency bands. Also called WiMAX this is a newer connection that is not available in all areas.
T-1 Lines: A T-1 line actually consists of 24 individual phone channels, each of which can be configured to carry voice or data. T-1 speeds are similar to DSL. It is possible to bundle multiple T-1 lines for even faster rates.
Satellite: Internet over Satellite (IoS) allows a user to access the Internet via a satellite that orbits the earth. This might be a good choice if your dental clinic is in the jungles of Borneo but not a realistic choice for most of us.
What connection should a dental office use?
In order of preference depending on local availability: