ABSTRACT
No firm rules can be given for selecting any particular design. Bridge design is complex, poorly researched and dominated by personal opinion derived from clinical experience, or lack of it. Many of the ground rules of bridge design were laid down in the early part of the last century by teachers who were trying to rescue the subject from the purely empirical approach used until that time. Although they were a major advance on what had gone before, these ground rules were not scientifically investigated. Yet they became accepted as irrefutable and remained relatively unaltered for over 50 years, despite a growing understanding in that time of related subjects such as the supporting structures of teeth in health and disease, and of occlusion and jaw function. In the last two decades, great developments have been made in restorative materials and techniques, so that bridges now fit better, look better and are stronger. This increased understanding and technical development should affect traditional ideas of design to a considerable degree.
