|Year : 2015 | Volume
| Issue : 1 | Page : 60-61
Two step impression technique for implant restorations
Pravinkumar G Patil1, Bipin Muley2
1 Division of Clinical Dentistry, School of Dentistry, International Medical University, Kuala Lumpur, Malaysia
2 Department of Prosthodontics, Government Dental College and Hospital, Nagpur, Maharashtra, India
|Date of Web Publication||2-Apr-2015|
Pravinkumar G Patil
School of Dentistry, International Medical University, Jalan Jalil Perkasa 19, Bukit Jalil, Kuala Lumpur, 57000
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Two-step (spacer used with the putty impression first and then the wash stage) impression technique is commonly used for making impressions in conventional fixed dental prosthesis. Impressions for implant fixed restorations are usually taken in 1-step. This article describes two-step impression technique for the implant fixed restorations. With the 2-step putty-wash impression technique described in this article, pressure developed on the impression analogues is negligible hence more accuracy and less deformation can be achieved.
Keywords: Dental implants, elastomeric impressions, impression
|How to cite this article:|
Patil PG, Muley B. Two step impression technique for implant restorations. J Dent Implant 2015;5:60-1
| Introduction|| |
Two-step (spacer used with the putty impression first and then the wash stage) impression technique is commonly used for making impressions in conventional fixed dental prosthesis. Nissan et al., studied the accuracy of 3 putty-wash impression techniques using the same impression material and concluded that 2-step putty-wash impression technique (with 2 mm wash spacer) is significantly more accurate than 1-step technique (putty and wash impression materials used simultaneously).  Impressions for implant fixed restorations are usually taken in 1-step. While two-step pick-up impression procedure for implant-retained overdentures is described by Gregory-Head and LaBarre.  This article describes two-step impression technique for the implant fixed restorations. For multiple implants, the impression analogues are usually splinted for stability to resist deformation caused due to pressure developed during impression making procedure.  Akalin et al., investigated the effect of impression technique and implant angulation on the impression accuracy and concluded that the models with implants placed parallel to each other exhibited greater accuracy than a model with implants placed at angles to each other.  With the 2-step putty-wash impression technique described in this article, pressure developed on the impression analogs is negligible hence more accuracy and less deformation can be achieved.
| Technique|| |
- At the prosthetic phase appointment for implant fixed restorations, make a custom impression tray using autopolymerizing or light polymerizing acrylic resin material (GC, GC United Kingdom Ltd., Newport Pagnell, UK) by keeping the open space for impression copings
- Remove the gingival healing abutments and place impression-analogues (preferably open-tray impression analogs) on the implants intraorally. Try in the custom tray and ensure minimum 4 mm space all around the impression analogues
- Adapt a double thickness modeling wax (Modeling wax; Deepti Dental Products, Ratnagiri, India) around the impression copings [Figure 1]. Furthermore, prepare and adapt a 2 mm thick vacuum formed polyethylene sheet spacer (Tray-Vac™ Complete, Buffalo Dental Manufacturing, NY) on remaining prepared teeth in the arch (if present) in usual manner [Figure 1]
- Make the impression with a putty elastomeric impression material (Aquasil Putty; Dentsply Austenal, York, PA). After setting, unscrew all the impression-analogs in the usual manner and remove the impression out of the mouth. Alternately polyether impression material can be used to add the stiffness
- Remove the impression-analogues, modeling wax and spacer (if present) from the putty impression [Figure 2]a
- Inject the light body impression material (Aquasil-light body; Dentsply Austenal, York, PA) on and around the gingival margins of the impression-analogs and prepared teeth. Also add the light body impression material on the spacer and wax areas of the putty impression and reseat the putty impression intraorally
- Inject light body impression material in the space between the tray and impression analogs if not filled completely. After setting, unscrew the impression-analogs and remove the impression and inspect it for the defects [Figure 2]b.
|Figure 1: Impression-analogs placed and covered with modelling wax. Note the spacer on remaining prepared teeth|
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|Figure 2: (a) Putty impression with analogs, wax and spacer removed. (b) Two-step putty-wash impression|
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| References|| |
Nissan J, Laufer BZ, Brosh T, Assif D. Accuracy of three polyvinyl siloxane putty-wash impression techniques. J Prosthet Dent 2000;83:161-5.
Gregory-Head B, LaBarre E. Two-step pick-up impression procedure for implant-retained overdentures. J Prosthet Dent 1999;82:615-6.
de Avila ED, de Matos Moraes F, Castanharo SM, Del′Acqua MA, de Assis Mollo F Jr. Effect of splinting in accuracy of two implant impression techniques. J Oral Implantol 2014;40:633-9.
Akalin ZF, Ozkan YK, Ekerim A. Effects of implant angulation, impression material, and variation in arch curvature width on implant transfer model accuracy. Int J Oral Maxillofac Implants 2013;28:149-57.
[Figure 1], [Figure 2]