Manuals_files/CD Manual 12.pdf - Removable Prosthodontics

Final Impressions - 24
- Insert by placing one side of the tray against one of the commissures of the mouth
and rotating the tray into the mouth while pulling outward on the commisure of the
contralateral side
- Seat tray front to back - use gauze over holes in tray
- Ensure the tray is centered and properly oriented
- Manipulate cheeks, lips and move mandible to sides for maxillary impression; hold
tray in position and have patient suck cheeks together, lift and move tongue forward
and toward the corners of the mouth
- Most polyvinyl siloxane materials set within approximately 6 minutes
- Material should not be more than l mm thick over border molding (otherwise it was
not fully seated)
Post-palatal Seal
- Mark the area of the post-palatal seal intraorally with indelible stick – glandular area
and vibrating line
- Place impression in mouth, line transfers to the impression
- Disinfect, refresh the line with a new indelible stick
- Prescribe a mechanical post-palatal seal
- Pour impression in Microstone
Criteria for Final Impression - Maxillary
! Post-palatal seal area recorded (vibrating line & displaceable tissue outline)
! Peripheries covered by a thin layer of impression material (.5-1 mm)
! Tray properly vented and compound relieved
! No significant voids
! Impression is stable and retentive when moderate pressure is applied to the canine region No
significant areas of "burn through"
! Accurately records available supporting structures
Criteria for Final Impression - Mandibular
! Peripheries covered by a thin layer of impression material (.5-1 mm)
! Tray compound properly relieved
! No significant voids
! Impression is stable with tongue at rest when moderate unseating pressure is applied
! No significant areas of "burn through" (distortion of the contours of the surrounding tissue)
! Mandibular retention evident - when tongue at rest and moderate vertical force applied
! Accurately records available supporting structures