[Loading and strength of single- and multi-unit fixed dental prostheses 2. Strength]

The ultimate strength of a dental prosthesis is defined as the strongest loading force applied to the prosthesis until afracture failure occurs. Important key terms are strength, hardness, toughness and fatigue. Relatively prevalent complications of single- and multi-unit fixed dental prostheses are porcelain and ceramic fractures. Afactor which also plays a role is the functional loading force from the entire orofacial system. With respect to the strength of multi-unit fixed dental prostheses, the length of the arch span between the abutment teeth, the pontic with the connectors and the possible cantilevers are the critical components. Components of the configuration ofabutment teeth of single- and multi-unit fixed dental prostheses which are relevant for its strength are the convergence angle and the design of(the area above) the (cervical) outline. Finally, the thickness of the porcelain or the ceramic (veneers) ofmetal-ceramic and all-ceramic single- and multi-unit fixed dental prostheses is of importance.