Ivoclar Vivadent SR Chromasit - Manual (Page 14)

14
Preparing the framework
After divesting, finish and adjust the metal surfaces to be
veneered as usual.
Framework after casting and sandblasting.
Appropriate application of retention beads is essential to ensure a favourable mechanical bond.
Fitting the copings.
Finishing the framework, particularly the marginal areas.
The retention beads should neither be too close
together nor should they be too wide apart – the
retentive effect would be lost in both cases. If the
Retention Adhesive is not applied appropriately, the reten-
tion beads may become submerged and lose their retentive
effect.
Designing frameworks with pontics
It is advisable to bring large pontics (eg upper centrals,
molars) to the same level as the neighbouring crowns by
applying a wax wire in a targeted fashion. This measure
helps to create a harmonious shade effect in bridges which
involve various layer thicknesses.
Before the sprues are attached, apply a thin layer of
Retention Adhesive onto the veneering surface (‘veneering
window’) of the wax model. Let the solvent evaporate for
approximately 30 seconds. Then, carefully apply the retention
beads onto the surface where required.