Trends in indirect dentistry: 5. Impression materials and techniques.

UNLABELLED: A fundamental pre-requisite for the construction of satisfactory indirect restorations is the ability to record an accurate and detailed impression of the dental structures. Knowledge of the key properties of the available impression materials and their handling behaviour is necessary if they are to be used effectively. A variety of techniques can be employed in different situations, each of which can be highly successful, but only if attention is paid to the detail of their execution and the clinician is aware of their individual limitations and pitfalls. Where imperfections occur, an appreciation of how they have been caused, and the strategies to take to prevent them will lead to greater success in impression taking. CLINICAL RELEVANCE: Current materials exceed our needs in terms of accuracy and stability, and yet the impressions produced are frequently flawed. By realizing why faults occur, being aware of the range of techniques available and having an understanding of the behaviour of materials, clinicians can achieve the quality in their impressions that is possible and necessary to provide excellence in indirect restorations.