Dental Impression Trays: Types, Sizes and How to Choose

An impression is only as good as the tray that carries it. Dental impression trays hold the impression material firmly against the arch so that an accurate, stable replica of the teeth and soft tissues can be captured. This guide covers the main types, sizes and how to choose.

Stock vs custom trays

Stock trays come in pre-formed sizes and are ready to use straight away — ideal for study models, opposing impressions and many routine cases. Custom (special) trays are made on a model for a specific patient and give the closest adaptation, often used for definitive prosthodontic impressions. Reusable stainless steel trays are the workhorse stock option in most clinics.

Perforated vs rim-lock

• Perforated trays have holes that let the material flow through and lock mechanically, helping retain alginate and similar materials.
• Rim-lock (solid) trays retain material with a beaded rim and are often used with adhesive, common for elastomeric impressions.

Upper, lower and sizing

Trays are shaped specifically for the upper (maxillary) and lower (mandibular) arches, with the lower trays relieved for the tongue. They are supplied in a range of sizes — typically from extra-small to extra-large — to match different arch widths. A well-fitting tray should cover all the teeth and extend slightly beyond them without impinging on the soft tissues.

Dentate and edentulous cases

Dentate trays are deeper to accommodate the height of the teeth, while edentulous trays are shallower and follow the residual ridge. Choosing the correct form for the case improves comfort and accuracy.

Material and care

Stainless steel trays are rigid, resist distortion and withstand repeated autoclaving, making them economical over time. Clean off all set material promptly, check for any bent edges that could affect seating, and sterilise between patients.

Dental Expert supplies stainless steel impression trays in a full range of upper and lower sizes to dentists and clinics across Italy and Europe.