Extensive clinical and basic research studies on root resorption have been conducted at the University of Sydney in Australia. The studies have covered the physical properties of root cementum, its chemical properties. The effects of types of orthodontic tooth movement, duration of force - light versus heavy forces and intermittent versus continuous forces - and upper vcersus lower jaw differences have also been investigated along with assessing genetic influence and possible prevention and interception protocols. Heavy forces were proved to cause more resorption than light forces, continuous forces caused more resorption than intermittent forces, and the amount of root resorption tended to decrease with the administration of fluoride. There is obvious repair of the resorption craters following the application of orthodontic forces. This information may help us to identify those individuals with a tendency to develop root resorption and ways to possibly prevent it.