Disadvantages of using a triple tray impression technique скачать в хорошем качестве

Disadvantages of using a triple tray impression technique

What are the main disadvantages of using Dual Arch "Triple-tray "impression technique : 1. Use of a partial and dual arch flexible tray: the use of the flexibility of partial plastic tray in a combination of lack of buccal-lingula support for the impression materials, makes this impression susceptible to distortion 2. Impression Technique: on this technique patient is asked to open the mouth full to allow the impression for both arches to fit in the mouth, then after we instruct the patient to bite. Often there is variability in the biting force and position that may create critical distortion during impression material setting time. 3. Dental lab Handling: pouring and handling the dual tray impression in the lab may affect the cast fabrication accuracy. The use of unilateral dental arch capture does not allow the dental lab to evaluate the contralateral teeth for shape, contour, and functional wear. 4. Occusion: Plastic articulator mounting of a quadrant arch are often unstable in comparison of full arch mounting, does not adequately replicate the patient's protrusive, laterotrusive , and mediotrusive movements and does not allow for centric relation/centric occlusion evaluation. 5. Final crown adjustment: the perception of dual arch impression techniques are time efficient, convenient and affordable in comparison with full arch technique may be wrong, if we consider the predictability of the final restoration may be compromised due to improper fit and occasion function, which creates extended chairside time for occlusal adjustments. Dual arch impression techniques may be used for single-unit posterior ( not distal tooth ) restorations. However, it is essential to acknowledge the limitation and disadvantages when selecting this technique