Frank has shown that least displacement will occur when an impression tray
has relief space and escape holes .
Properties of the tray adhesive of an addition polymerizing silicone to impression tray
The influence of impression trays
on the accuracy of stone casts poured from irreversible hydrocolloid impressions.
7,8) Evolution of impression trays
took place during this era in order to carry the impression material.
After the tooth is prepared, the assistant will fill this impression tray
with low--viscosity VPS and the dentist will seat this relined triple tray intra--orally to take a final impression to capture the abutment details.
There are ready made impression trays
available in market to record impression of patient known as stock metal trays and usually thickness of the tray is around 4 milli meter.
Simple measures like no over loading the impression tray
, fast setting materials, ensuring sufficient aspiration, treatment in upright position, frequent cessation of treatment etc can be used.
These include overextended borders especially in the posterior palatal seal region and the distolingual flange of the lower arch or while recording maxillary impression with overloaded impression tray
, poorly retained dentures, an increased vertical dimension of occlusion has also been suggested as precipitating gagging.
With dual arch trays there is a lack of consensus about which impression tray
should be used, what viscosity of impression tray
material is needed and which side of the dual-arch impression should be poured first to minimize distortion.
3) Impression material dislodged from impression tray
Imagine you've just removed an impression tray
from a patient's mouth, only to find that there is a void in a critical area, or that the teeth have contacted the tray, requiring the impression to be taken over.
selection is an empirical step before actually recording a dental impression.