Snap set technology in the VPS impressions materials

15 Dec 2016 - 34159

Impression of the abutments is a significant procedure during the prosthodontic treatment, as it could directly affects the precision of the cast and the fit of the final restoration. The chemical and physical properties of elastomeric impressions materials may influence the accuracy of the final impressions. 

Selection of the impression material should take in consider : the consistency and flow properties, ease of handling, the setting time and dimensional stability.

The most used elastomeric impression materials for fixed and  removable prosthodontic restorations are polyvinylsiloxanes (PVS) and polyethers (PE).

Polyvinylsiloxane impression materials provide simplicity, high dimensional stability and accuracy, superior elastic recovery from undercuts and low viscoelastic properties, low distortion, adequate tear strength varying with filler rate and viscosity, high flow characteristics, short setting time, and multiple pouring from one impression.

Impression materials generally require compromises. They either exhibit good flow characteristics or stability.  The VPSbased precision impression material Honigum, however, is different. Thanks to the DMG-patented rheologically active matrix Honigum-Light, Honigum-Mono and  Honigum-Heavy yield best results in both disciplines.And the DMG Putty variants overcome the opposites at exactly the most critical point for the dentist and treatment.
With its unique Snap-Set technology the hand-mix Honigum-Putty combines a comfortable working time with a very short setting time.

Fig. 1

The chief complain of the patient was – the teeth are too big and the color was not pleasant. 

Fig. 2

The intra oral aspect of the 11, 21 oxid zirconia crowns showed, poor cervical adaptation of the crowns, inflamation of the gingiva, inadequate surface contact, high opacity of the restorations, no shape integration in the arch.

Fig. 3

The crowns were removed and the composite restorations were replaced. 

Fig. 4

Two provisionals were made in the office using the initial situation using Luxatemp composite. The shape was changed intraoraly with a direct mock-up according to the adjacent teeth.

Fig. 5

The color for the final restoration were made at the beginning of the impression, before the dehydration of the teeth that appear during this session.

Fig. 6

After the healing of the gingiva the buccal margins were placed subgingivaly because of the high chromatic color of the abutments. The final finishing of the abutments were made with Arkansas stone.

Fig. 7

Finishing of the cervical area were made using the cord retraction in order to protect the epithelial insertion.

Fig. 8

The final aspect of the preparation.

Fig. 9

After the finishing of the margins the second cord were placed to retract the the marginal gingiva in horizontal direction. The second cord after the placement should be seen totally when we look from incisal direction. 

Fig. 10

The aspect of the gingiva after the removal of the second cord. The space for the impression material we can see it very well.

Fig. 11

For this case I decide to use Honigum from DMG. The light material is very flowable and will fill all the space made by the second cord.

Fig. 12

The putty material is the most flowable material I ever used. Thanks to the DMG-developed Snap-Set technology the new Honigum-Putty offers a so far unrivaled combination of comfortable working time and short time in mouth. Its generous working time reduces the »mix stress« to a minimum. Deformations due to already set material are prevented, and micro movements are reduced by the quicker cross linking. For the patient the shorter time in mouth translates into significantly more comfort during the treatment.

 This flowable properties also prevent the high pressure of the material during the insertion that can do in some cases movements of the abutments. 

Fig. 13

Other advantages of this material are:

Exceptional detail reproduction 

Outstanding stability in the tray and intraorally

Remarkable flow properties under light pressure

Balanced hydrophilicity

Neutral taste and honey scent

A very good impression of the sulcus were obtain using one step wash technique.

Fig. 14

After the impression the color of the abutment were taken using natural die material color(ND).

Fig. 15

The aspect of the control model.

Fig. 16

The isolation before the cementation of the two crown. In this case I decided to cement one by one using Variolink Esthetic DC from Ivoclar.

Fig. 17

For this case I choose to use a feldspathic ceramic on refractory die.

Fig. 18

The final aspect of the restorations after one month from the cementation.

Fig. 19

The doctor and the patient were very happy with the final aspect.

 

Conclusions

1. A good impression material gives high precision of the ceramic restoration
2. Snap set technology gives a comfortable working time and short time in mouth

Bibliography

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2. Craig RG and Sun, Z. Trends in elastomeric impression materials. Operative Dent 1994; 138-45.
3. Chee WW and Donovan TE. Polyvinyl siloxane impression ma-terials: a review of properties and techniques. J Prosthet Dent 1992; 68: 728-32.
4. Mandikos MN. Polyvinyl siloxane impression materials: an update on clinical use. Aust Dent J 1998; 43: 428-34.
5. Lee EA. Impression material selection in contemporary ?xed prosthodontics: technique, rationale, and indications. Compend Contin Educ Dent 2005; 26: 780, 782-4, 786-9