This document discusses common problems that can occur with dental impressions and how to identify and correct them. It outlines issues such as inadequate marginal detail, internal bubbles, tears, drags and pulls. Specific techniques are provided to avoid each problem, such as using an intraoral tip to flush out air when extruding light-body material to prevent tears, only placing impression material where the teeth are to prevent drags and pulls, and ensuring proper tray selection and material mixing. The overall goal is to discuss common impression complications and how they can be identified and addressed.

1. Identification & CorrectionIdentification & Correction
of common impressionof common impression
problemsproblems
Dr. M.K.PATELDr. M.K.PATEL
BDS(WALES).MFGDP(UK).RCS(Eng) DipBDS(WALES).MFGDP(UK).RCS(Eng) Dip
Implant. MSc ImplantologyImplant. MSc Implantology

2. Common ComplicationsCommon Complications
Marginal detailsMarginal details
BubblesBubbles
TearsTears
PitsPits
VoidsVoids

3. Marginal DetailMarginal Detail
Most common complaint from theMost common complaint from the
technician is inadequate marginal detailtechnician is inadequate marginal detail
Will result in open margins and inadequateWill result in open margins and inadequate
fitfit

4. Internal BubblesInternal Bubbles
As a result of fluid accumulationAs a result of fluid accumulation
Air entrapmentAir entrapment
Bubbles affect long term success ofBubbles affect long term success of
looting agentlooting agent
2 stage wash impression technique can2 stage wash impression technique can
cause difficulty in seatingcause difficulty in seating

5. How to a avoid tearHow to a avoid tear
Flushing & drying of prep prior toFlushing & drying of prep prior to
impressionimpression
Use an intra oral tip into the deepest partUse an intra oral tip into the deepest part
of the prep & extrude the light bodyof the prep & extrude the light body
material making sure the tip is in thematerial making sure the tip is in the
material, this will force air out of thematerial, this will force air out of the
impressionimpression

6. Marginal tearMarginal tear
Caused by incomplete setting of materialCaused by incomplete setting of material
Not removing all the old impressionNot removing all the old impression
material prior to impressionmaterial prior to impression
If the syringe material is to thick then youIf the syringe material is to thick then you
must retract more retraction cordmust retract more retraction cord

7. Drags & PullsDrags & Pulls
Most common complication with material i.e. putty or heavyMost common complication with material i.e. putty or heavy
body materialbody material
A pull results when a material creates a fold atA pull results when a material creates a fold at
the gingival aspectthe gingival aspect
These deformities lead to D3 bonding of the trayThese deformities lead to D3 bonding of the tray
and sliding into positionand sliding into position
Impression material beyond it’s working timeImpression material beyond it’s working time
Failure for the impression material to adapt toFailure for the impression material to adapt to
the teeththe teeth
Exceeding materials prior 2 intra-oral insertionExceeding materials prior 2 intra-oral insertion
Insertion of tray in 1 directionInsertion of tray in 1 direction

8. How to avoid Drags & PullsHow to avoid Drags & Pulls
Remove intraproximal impressionRemove intraproximal impression
material, so the impression can be re-material, so the impression can be re-
inserted without interferenceinserted without interference
Place the light body over the wholePlace the light body over the whole
impressionimpression
Impression should be filled where theImpression should be filled where the
teeth areteeth are
Drags are usually incorrect ableDrags are usually incorrect able

9. Tray SelectionTray Selection
Tray should not contact the soft tissues, only atTray should not contact the soft tissues, only at
the basethe base
If the plastic tray needs to be bent you could useIf the plastic tray needs to be bent you could use
an alcohol tort to bend the trayan alcohol tort to bend the tray
An adhesive should be usedAn adhesive should be used
Must make sure the primary putty adders wellMust make sure the primary putty adders well
prior to taking the second impressionprior to taking the second impression
Dry the putty and the teeth before second stageDry the putty and the teeth before second stage
Latex can affect the putty so an alternative isLatex can affect the putty so an alternative is
usedused

10. Inadequate material mixingInadequate material mixing
Make sure material has uniform colourMake sure material has uniform colour
and no strikingand no striking
Striking is most common with impressionsStriking is most common with impressions