Dr. Manuel Kalo presents a simple solution for patients prone to gagging during impression taking
A 46 year old patient required the replacement of defective composite and amalgam restorations in teeth 14 and 15 with existing distal (14) and mesial (15) approximal caries (fig. 1).
Figure 1: initial situation
The teeth were to be restored with ceramic restorations.A special challenge was the patient’s pronounced gagging reflex.
In order to take an accurate impression of any cavity prepared according to minimally-invasive principles, the impression material must exhibit specific properties.
The wash material should be applicable without bubbles, remain in situ on the preparation without slumping, have optimal flow characteristics under pressure, and provide precise detail reproduction.The tray material should support the properties of the wash material.The preferred tray material should be one with a true putty consistency and with optimal resistance when positioned, in order not to trigger the patient’s gagging reflex.Both materials should be suitable for the double-mixing technique with matching setting times.
For the double-mixing technique, DMG’s Honigum-MixStar Putty and Honigum-Light were used because these materials fulfilled all the above conditions.The materials were mixed in the MixStar-eMotion automatic mixing unit, which is programmable for working time and setting time in the mouth.
In order to guarantee stability of the impression material upon removal from the mouth, a non-perforated impression tray, coated with DMG Tray-Adhesive, was used.
After removal of the defective restorations, excavation of the caries, and preparation of the cavities (fig. 2), an impression was taken using the double-mixing technique.
Figure 2: preparing the cavities Figure 3: applying the DMG tray-adhesive
For this purpose, the impression tray was first coated with Tray-Adhesive (fig. 3).While the assistant filled the impression tray with Honigum-MixStar Putty (fig. 4), the dentist filled the cavities and covered the occlusal surfaces of the adjacent teeth with bubble-free Honigum-Light (fig. 5). During the wash material’s 1:45 minute working time the impression tray was inserted in the patient’s mouth using light pressure and left in situ for at least 3:15 minutes. The acoustic signals of the MixStar-eMotion’s timer are very helpful for the clinician’s time management. After the setting time had elapsed, the impression was removed from the patient’s mouth, which, particularly in the area of the prepared teeth, must be done parallel to the axis of the teeth. The material’s putty consistency, which remains in that state even after hardening, makes this process significantly easier. After drying the impression, the result was inspected and the impression stored at a maximum temperature of 25°C.
Figure 4: hygienic filling of the impression tray, using Honigum-MixStar Putty
Figure 5: homogeneous and bubble-free syringing of the preparation, using Honigum-Light
Figure 6: perfect impression result
The material properties of Honigum-Mixstar Putty and Honigum-Light provided optimal results.The impression was a bubble-free, finely detailed reproduction of the entire preparation, including any difficult to access areas and preparation lines.
Thanks to the rheologically active matrix of Honigum-Light, which delivers excellent stability yet very good flow characteristics, and putty-like characteristics of Honigum-Mixstar Putty, which provides patient-friendly resistance, there was no irritation of the sensitive areas in the patient’s mouth due to overflowing or running impression material. Consequently no gagging occurred.
The precise reproduction of the preparations, by means of combining the two impression materials, was demonstrated impressively by the perfect fit of the final restorations (fig. 7).
Figure 7: perfectly fitting final restorations
The complete DMG range, including Honigum, is distributed in the UK and Ireland by DMG Dental Products (UK) Ltd. For further information contact your local dealer or DMG Dental Products (UK) Ltd on 0044 1656 789401, fax 0044 1656 360100, email firstname.lastname@example.org or visit www.dmg-dental.com