Impression Techniques for Implant Prostheses

1. IMPRESSION TECHNIQUES
FOR IMPLANT PROSTHESES
AAMIR GODIL
FIRST YEAR P.G.
DEPARTMENT OF PROSTHODONTICS
M.A.R.D.C.

2. OUTLINE
• INTRODUCTION
• MATERIALS REQUIRED
• IMPRESSION TECHNIQUES
• GINGIVAL MASKING
• ERRORS
• LITERATURE REVIEW
• CONCLUSION

3. INTRODUCTION
• Accurate recording of spatial implant position is required to obtain a proper support
to definitive restoration with passive fitting.
Conrad et al (2007)
Implants V/S Crowns and Bridges
• It is more critical to record 3- dimensional position of the implants as they occur
intraorally.
• Natural teeth have a PDL to compensate for minor inaccuracies while implants have
not.
Pesun IJ (1997)

4. WHY SHOULD YOU MAKE
IMPLANT IMPRESSIONS?
Position Depth
Axis
(Angulation)
Soft Tissue Contour
(Emergence Profile)

5. WHAT ALL DO YOU NEED TO
MAKE IMPLANT IMPRESSIONS?

6. WHICH IMPRESSION MATERIAL
TO CHOOSE?
• Least stable
• Low tear strength
• Least desirable to use
due to limitations of
material
• Toxic to bone
• Very rigid
• Very Stable
• Most hydrophilic
• Toxic to bone
• Relatively Stable
• Slow set
• Unpleasant taste to
patient
• Minor bone toxicity
• Very stable
• Multiple viscosities
available POLY
VINYL
SILOXANE
POLY-
SULFIDE
OTHERS
(HYDRO-
COLLOIDS)
POLY-
ETHER

7. HOW TO MAKE AN IMPRESSION
FOR IMPLANT PROSTHESES?
Implant Level Impressions
1. Pick Up (Open Tray)
2. Transfer Type (Close Tray )
Abutment Level Impressions
1. Direct Technique
2. Indirect Technique

8. IMPLANT LEVEL IMPRESSIONS

9. Open Tray
More accurate for multi unit impressions
In cases with implant/abutment
angulations and path of insertion
withdrawal Less accurate for multi unit
cases
Closed Tray
Less accurate for multi unit impressions
IMPLANT LEVEL IMPRESSION TECHNIQUES

10. CLOSED TRAY
IMPRESSION TECHNIQUE

14. Indications
Liou Ad (1993)
• Limited inter arch space
• Tendency to gag
• Difficult access in the
posterior region of the
mouth
Advantages
Conrad H. (2007)
• Easier
• Suitable for short inter
arch distance
• Visual fastening of the
analog to the coping is
more accurate
Disadvantages
Conrad H. (2007)
• Inaccuracies with
recovery and subsequent
deformation of
impression material may
be encountered with
nonparallel implants
• Not suitable for deeply
placed implants

15. SPLINTING FOR MULTIPLE IMPLANT IMPRESSION
• The common practice of joining the direct transfer copings with acrylic resin is an
attempt to
– stabilize the copings against rotation during fixture or abutment analog fastening
– control the relationship between implants in a rigid fashion
(Spector MR, Donovan TE, Nicholls JI. An evaluation of impression techniques for osseointegrated implants.J Prosthet Dent 1990;63:444–447)
• Assif et al. and Naconecy et al. showed that splinting technique was significantly
more accurate than unsplinted techniques
(Assif D, Marshak B, Schmidt A. Accuracy of implant impression techniques. Int J Oral Maxillofac Implants 1996;11:216–222)
(Naconecy MM, Teixeira ER, Shinkai RS, Frasca LC, Cervieri A. Evaluation of the accuracy of 3 transfer techniques for implant-supported
prostheses with multiple abutments. Int J Oral Maxillofac Implants 2004;19:192–198)
OPEN TRAY
IMPRESSION TECHNIQUE

17. STEPS IN SPLINTING MULTIPLE IMPLANTS FOR IMPRESSION

18. 1. Autopolymerising resin
(sectioned and reconnected)
2. Impression Plaster (PI) and
Polyether (FI)
2. Impression Plaster
3. Autopolymersing resin at the
time of impression
3. VPS bite registration material
J Adv Prosthodont. 2011 Dec;3(4):177-85

24. ALL ON SIX

25. Indications
• Multiple implants
• Very closely located
implants
Advantages
Heather J.
• Reduces the effect of the
implant angulation
• Reduces the deformation
of the impression material
• Removes the concern for
replacing the coping back
into its respective space in
the impression.
Disadvantages
Heather J.
• Some rotational
movement of the
impression coping when
securing the implant
analog may occur
• Blind attachment of the
implant analog to the
impression coping may
result in a misfit of
components

26. ABUTMENT LEVEL IMPRESSIONS
Simple provisional
restoration
fabrication
For custom-made
abutments
Selecting
abutments in the
laboratory

27. DIRECT- ABUTMENT LEVEL
IMPRESSION TECHNIQUE

28. INDIRECT- ABUTMENT LEVEL
IMPRESSION TECHNIQUE

29. GINGIVAL MASKING

30. WHAT SHOULD YOU SEND
TO THE LAB?
Lab prescription
Detailed with all
required prosthetic
design and case
details.
Appropriate and
accurate impressions
Implant level
Abutment level
Mounted models
Preoperative
Diagnostic wax up
Necessary restorative
components for
implant
Temporary abutments
Impression analog
Implant analog
Necessary abutment
screws

31. WHAT ARE THE PROBABLE ERRORS?
HOW DO YOU MINIMIZE THEM?
VERIFY THE SEATING OF
COMPONENTS
IMPROPER INTERFACE
BETWEEN IMPRESSION
POST AND IMPLANT
ANALOGUE
ERRORS IN
IMPRESSION MAKING
• Latex gloves with PVS
impression material
• Non-uniform thickness of
material

32. LITERATURE REVIEW

34. Three-Dimensional Accuracy of Implant
and Abutment Level Impression Techniques: Effect on
Marginal Discrepancy
With comparison of different impression methods, including abutment level and
implant level (closed tray and open tray), no significant difference was noted
Journal of Oral Implantology

36. CONCLUSION

37. • Precise impression methodology would decrease the
failures related to the supra structure fabrication
Ozkane, 2006
• Imprecise superstructure fit results in mechanical and
biologic consequences that disrupt the function of
dental implants
Heather J. et al, 2007

38. Thank You