Ivoclar Vivadent IPS InLine System - Manual (Page 27)

27
InLine
® – Conventionally Layered
IPS
Framework design criteria
The framework design is key to the success of durable metal-ceramic restorations. The more attention given to the framework
design, the better the final results and the clinical success will turn out to be.
1. functional support of the veneering ceramic
The framework reflects the shape of the tooth in a reduced form. It should be designed in such a way that it supports the
cusps and incisal edges resulting in a virtually even layer thickness of the veneering ceramic in the cusp-fissure area. In this
way, the masticatory forces occurring during functional chewing are exerted on the framework rather than on the veneering
ceramic. Therefore, the framework must not show any angles and edges (see diagram) so that the masticatory forces do not
result in tension peaks, which may cause delamination and cracks. Any sharp angles or edges should be removed in the wax-
up rather than by grinding the metal framework. The wall thickness of the metal framework for single crowns must not be
less than 0.3 mm and for bridge abutments 0.5 mm after finishing (see diagram). For further information, please refer to the
Instructions for Use of the corresponding alloy.
Anterior crowns
wrong
correct wrong
correct wrong
correct
Premolar crowns
Molar crowns
IPS
InLine
– Conventionally Layered