An alternative impression technique for mobile teeth

05/03/2023Mujtaba Ashraf1

AN ALTERNATIVE IMPRESSION TECHNIQUE FOR MOBILE TEETH

Evangelia Lampraki, DDS, A Konstantinos M. Chochlidakis, DDS, B Evangelos Rossopoulos, DDS, & Carlo Ercoli, DDS

Presented by:

Mujtaba Ashraf

MDS 2nd

Department of Prosthodontics

§ JPD § Vol. 116 § Issue 2 § August 2016 §


Contents

IntroductionMaterials usedTechniqueAdvantagesDisadvantagesDiscussionConclusionReferences


Introduction

Patients presenting for immediate denture therapy might have remaining teeth that are extremely mobile and/or misaligned.

Challenges during immediate denture impression procedures in such patients include preventing accidental exfoliation of mobile teeth during the impression procedure and capturing in detail the teeth and buccal tissues adjacent to remaining teeth, which frequently have very different long axes.


Numerous immediate denture impression techniques have been described.The sectional impression technique involves the use of custom sectional trays, custom trays in combination with stock trays, or custom trays with open buccal areas adjacent to the remaining teeth.

Gardner LK, Parr GR, Rahn AO. Modification of immediate denture sectional impression technique using vinyl polysiloxane. J Prosthet Dent 1990;64: 182-4.


The custom trays are fabricated on casts obtained after a preliminary impression has been made.

A combination of impression materials, including modeling plastic impression compound, zinc oxide and eugenol paste, plaster, baseplate wax, irreversible hydrocolloid, and polyvinyl siloxane (PVS) have been used to make impressions of all hard and soft tissues.


The use of stock and custom trays with holes to fit an amalgam condenser to prevent movement of mobile teeth while removing the impression from the patient’s mouth has been described.Similar methods involve the use of copper bands placed over the mobile teeth and blocking the undercuts with wax before impression making.

Soni A. Use of loose fitting copper bands over extremely mobile teeth while making impressions for immediate dentures. J Prosthet Dent 1999.


Recently, an impression technique for mobile teeth has been described, Irreversible hydrocolloid on a modified plastic stock tray that leaves exposed the labial or buccal surfaces of the mobile teeth was used.

Lee H, Park C. A method to make a preliminary impression of mobile teeth. J Prosthet Dent 2009;102:52-3.


With this technique, the irreversible hydrocolloid material captures the nonmobile teeth, the lingual surfaces of the mobile teeth, and the edentulous areas while PVS recording material is used to capture the labial surfaces of the teeth at risk.

Lee H, Park C. A method to make a preliminary impression of mobile teeth.J Prosthet Dent 2009;102:52-3.


Materials Used

The impression is made with a stock tray and acombination of• Low viscosity Polyvinyl Siloxane (PVS) and• Polyether(PE)• Irreversible hydrocolloid impression materials.

These materials quickly polymerize and do not adhere to each other intraorally.The impression is then separated in 3 different directions to prevent any movement of the mobile teeth and reassembled extraorally before pouring.


TECHNIQUE

1. Select a stock tray and evaluate for proper fit in the patient’s mouth. Modify with utility wax if needed until appropriate extensions are achieved.

2. Inject low viscosity PVS impression material (Imprint 3M ESPE) on the buccal aspects of mobile teeth


3. Inject low viscosity PE impression material (Impregum; 3M ESPE) on the lingual aspects of the mobile teeth


4. After the polymerization of the elastomeric materials, mix irreversible hydrocolloid (Jeltrate; Dentsply Caulk) and load it into the tray. Place the tray intraorally and maintain it in position until the material sets.


5. Remove the tray from the mouth in a vertical direction. After removing the tray, the 2 pieces of PVS and PE materials will still be present intraorally, generally engaged in the proximal areas and/or undercuts.

6. Remove the polymerized PE impression material in a lingual direction.

7. Remove the polymerized PVS impression material in a buccal direction.


8. Assemble these 2 pieces in an appropriate relationship (buccal or lingual) in the tray with the irreversible hydrocolloid.

9. Pour dental stone into the tray.


10. After the dental stone sets, separate the cast from the tray. The 2 pieces of PVS and polyether materials will still be engaged on the cast in the proximal areas and/or undercuts.


11. Remove the polyether and PVS impression materials in 2 different horizontal directions.


The complete diagnostic cast


DISCUSSION

This technique addresses some of the limitations of previously described methods for obtaining an accurate impression of mobile and/or misaligned teeth.Although the sectional tray technique described in the literature captures the edentulous and dentate areas accurately, its use is limited in patients with hypermobile periodontally involved teeth where the risk of extraction during separation of either the preliminary or the secondary impression is significant.


The techniques described by Goldstein and Soni eliminate the risk of extraction of the mobile teeth during the impression procedures. However, inaccurate capturing of the teeth and anatomic structures around the teeth and patient discomfort are problems related to these methods.


Lee and Park described a technique that was modified by Çomut, in which the impression of mobile anterior teeth can be easily, accurately, and comfortably made for the patient. This technique, though, can become challenging when capturing posterior hypermobile and misaligned teeth or soft tissues under fixed dental prostheses.


1. Minimal risk of accidental tooth extraction during the impression procedure.

2. Patient discomfort due to gag reflex is minimal.

3. After the production of the stone cast, the stock tray can be easily separated without the risk of fracturing the stone.

Advantages


Disadvantages

This technique is the use of 3 different impression materials and their total setting time. Thus the total time of this impression procedure is more than when a single impression material is used.

The potential error caused by reassembling the PE and PVS pieces in the tray with the irreversible hydrocolloid material or by dislodging those 2 pieces while pouring stone using a vibrator.


This article presents a technique for making an accurate stone cast of mobile and/or misaligned teeth combining elastomers and irreversible hydrocolloid impression materials.This technique provides an alternative, easy, accurate, and safe way to make a preliminary impression of mobile, periodontally involved teeth.

Conclusion


1. Lee H, Park C. A method to make a preliminary impression of mobile teeth. J Prosthet Dent 2009;102:52-3.

2. Çomut AA. Tray modification for making impressions of mobile teeth. J Prosthet Dent 2013;109:341-2.

3. Cupero HM. Impression technique for complete maxillary immediate denture. J Prosthet Dent 1978;39:108-9.

4. Goldstein GR. An alternative immediate complete denture impression technique. J Prosthet Dent 1992;67:892-3.

5. Gardner LK, Parr GR, Rahn AO. Modification of immediate denture sectional impression technique using vinyl polysiloxane. J Prosthet Dent 1990;64:182-4.

6. Soni A. Use of loose fitting copper bands over extremely mobile teeth while making impressions for immediate dentures. J Prosthet Dent 1999;81:638-9.

References


Education

An alternative impression technique for mobile teeth