A PHYSIOLOGIC IMPRESSION TECHNIQUE FOR RESORBED MANDIBULAR RIDGES

by Manisha Herekar, Megha Sethi, A Fernandes, Harish Kulkarni

Presented byDushyant Chauhan Resident Dept of Prosthodontics and Crown & Bridge

Index

• Prelude• Impression• Aim & Objective• Resorption of ridges• Technique• Critical review• Discussion• Conclusion

Prelude

Making a definitive impression of an edentulous arch can be challenging specially with additional complications :

• Mandibular ridge• Flabby tissue• High muscle attachment

Impression

A negative likeness or copy in reverse of the surface of an object; an imprint of the teeth and adjacent structures for use in dentistry. GPT-8

A complete denture impression is a negative registration of the entire denture bearing, stabilizing, and border seal areas present in edentulous mouth.

Impression Techniques

Impression techniques• pressure • non pressure• selective pressure techniques• Other techniques

AIM & OBJECTIVE

• Emphasizes on the concept of tissue placement and determination of the extent of mucobuccal denture extension achieved by close fitting tray and a viscous impression material.

• The objective is to develop a physiologic impression with maximum support of both hard and soft tissues

Resorption of ridge

Cause• Long term edentulism • use of ill-fitting denturesChallenges• Retention• Stability• tissue support

Technique

- Make a preliminary impression of the edentulous arch using McCord's technique

• Refine the impression using irreversible hydrocolloid.

• Remove, disinfect and pour the impression with dental plaster within 12 minutes.

• Retrieve the casts and adapt spacer wax.

• Fabricate a custom impression tray on the preliminary.

• providing the required relief.

• Make final wash impression with light body Poly Vinyl Siloxane impression material

MODEL RETRIEVED

Critical review

• Retention of alginate with compound in primary impression

• Spacer design not specific• Other factor for stabilizing denture like neutral

zone concept.

Discussion

• The problems associated with class IV mandibular ridge are many, most evident being the frustration of the patient due to lack of retention of denture.

• Alternate options being:– Implants

Problems associated with implant• Cost• surgery

• Conventional dentures still remain as a viable solution for majority of the ageing population.

• Impression of the completely edentulous arch is the single most contributing factor towards achieving retention, stability and support.

• Modifications of impression techniques have been tried in the past with a view of maximizing retention, stability and support of the denture

• The focus is on primary impression, spacer design , secondary impression and the choice of impression materials

Conclusion

• This technique combines both traditional and contemporary methods and the amalgamation leads to prosthesis with better retention and stability

• Use of a viscous material in a close fitting tray allows physiological compression of tissues in the primary stress bearing areas. Elastomeric impression material helps in recording finer details of the ridge. Thus this technique helps in maximizing the functional support from the edentulous ridge

References

• Heartwell CM. Textbook of complete dentures. 5th ed. London: Lea & Febiger; 1993. p. 227-5

• Boucher CO.A critical analysis of mid-century impression techniques for full dentures. J Prosthet Dent 1951;1:472-914.

• Fernandes A, Dua N, Herekar M. Corrective primary impression technique. Open Dent J.2010;4:27-28

• McGamy TJ, Nimmo A, Skiba JF, Ahlstrom RH, Smith CR, Koumjian JH. Classification system for complete edentulism. J Prosthodont1999;8:27-39

• Krishna Prasad D. , Divya Mehra & Anupama Prasad D. prosthodontic management of compromised ridges and situations nujhs vol. 4, no.1, march 2014, issn 2249-7110

• Bhupender Yadav, Manisha Jayna, Harish Yadav, Shrey Suri, Shefali Phogat, and Reshu Madan comparison of different final impression techniques formanagement of resorbed mandibular ridge: a case report Hindawi publishing corporation case reports in dentistry volume 2014, article id 253731, 6 pages

• Tryde G, Olsson K, Jensen SA, Cantor R, Tarsetano JJ. Dynamic impression methods. J Prosthet Dent 1965;15:1023-34

Thankyou