[Loading and strength of single- and multi-unit fixed dental prostheses 2. Strength]. / Op kronen en bruggen uitgeoefende krachten en het weerstaan daarvan 2. Mechanische belastbaarheid.

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.

[Loading and strength of single- and multi-unit fixed dental prostheses. 1. Retention and resistance]. / Op kronen en bruggen uitgeoefende krachten en het weerstaan daarvan. 1. Retentie en resistentie.

The degree to which single- and multi-unit fixed dental prostheses are able to withstand loading forces is dependent, among other things, on the quality of their retention and resistance. The quality of the retention and resistance of the configuration of an abutment tooth prepared for a metal and metal-ceramic single-unit fixed dental prosthesis is determined by the configuration's convergence angle, the height, the volume, the interocclusal space, the cervical outline design, the additional preparations, the quality of the (build-up) restoration, and the surface roughness. A silicate ceramic single-unit fixed dental prosthesis is attached through adhesion using a composite cement, but the retention and resistance of an oxide ceramic single-unit fixed dental prosthesis is dependent on the abutment tooth configuration. Most types of multi-unit fixed dental prosthesis have the following additional retention and resistance determining factors: the position in the occlusal system, the number of abutment teeth and their mutual configurations, and the length of (cantilever) pontics. A resin-bonded fixed partial denture's retention and resistance are determined by its bonding as well as its enamel surface coverage and its resistance preparations.