1 Impression Techniques of Dental implants Dr Sabreen
1 Impression Techniques of Dental implants Dr. Sabreen Waleed Aswad
Dental implant is a prosthetic device of alloplastic material(s) inserted into the oral tissues to provide retention and support for a fixed or removable prosthesis Osseointegration : direct structural and functional connection between the living bone and the surface of implant without interposition of connective tissue 2
Implant components 1. Main components Ø implant body or fixture Ø Abutment Ø Superstructure 2. Accessories a) Surgical Ø Healing screw Ø Gingival former b) Prosthetic Ø Impression post Ø Implant analogue 3
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Impression materials The impression material used should be Ø easy to mix Ø accurate reproduction of details. Ø impression material used should be flexible Ø Enough working time Ø rapidly setting Ø And dimensionally stable following removal from the mouth. The materials that fulfil these criteria are Vinyl polysiloxanes silicones and polyether rubber base impression materials. 5
6 IMPRESSION TECHNIQUES Implant impression techniques can be classified as either direct (open tray, pick up) and indirect (closed tray, transfer).
Indirect (Closed tray, transfer) technique 7 (a)Exposed fixture head after removal of the healing Abutment (b) closed tray impression coping screwed in place
Closed tray technique 8 (c) light bodied impression material syringed around impression coping (d)impression taken in a stock tray.
Closed tray technique 9 (e) impression with details of soft tissue around the implant and adjacent teeth (f) impression coping repositioned into the impression
Snap-On Impression Technique 10
Indications 1 - Limited inter-arch space 2 - Tendency to gag 3 - Difficult to access in posterior region Advantages: 1. Time saving 2. More comfortable for both the clinician and the patient 3. Easy to manipulate 4. Does not need for especial preparation in the tray 11
Disadvantages: 1. Might be less accurate especially in multiple fixtures. 2. With the increased divergent of the posts the impression material might be distorted 12
Open tray technique 13 (a) impression copings in place, (b)open custom tray with window sealed with wax, (c)impression in place with the tips of the impression copings projecting through the wax window , (d) the completed impression with the impression copings in situ
The direct technique can be further subdivided into splinted 14 and non-splinted techniques. The splinting procedure is recommended in case of multiple implants to decrease the amount of distortion and to improve impression accuracy and implant stability.
Ø Open tray technique indicated in case of multiple implants and very closely located implants. 15 Ø The advantage of this technique is reduce the errors, more precise. Ø Disadvantages include: o Take time o Not suitable for pt. with limited inter-arch space, uncooperative pt. and gag pt.
Digital Implant Impression 16 More recently, one of the major developments in implant prosthodontics has been the adoption of engineering principles in the form of computeraided design and computer aided manufacturing (CAD/CAM) to construct implant prosthesis. This technology utilizes 3 - D intraoral scanners which alter the way we take impressions.
Requirements of a digital impression The main requirements for the CAD/CAM are (1) the digital scanner (2) software that processes the data and creates a CAD model (3) a production technology that transforms the data set into the desired product by means of CAM 17
Advantages of the digital impression are as follows: 1. Improved patient acceptance. 2. Reduced distortion of impression materials. 3. time effectiveness 18
Accuracy of impression Many factors determine the accuracy of an impression: Number of implants Position of implants Impression material Clinical training 19
20 Thank you
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