What are Dental Impression Trays?

I. Dental Impression

Dental impression is the negative registration of oral structures obtained with the help of impression materials, to produce a positive replica of the structure to be used in production of a dental restoration.

To finish the making of dental impression, a stock or special dental impression tray that could roughly suit oral structures will be needed, as well as proper impression materials.

The liquid or semi-solid impression materials should be mixed in glass dappen dish first and placed on the rough surface of dental impression tray. Then the impression tray is put in patient’s mouth for few minutes (the period depends on the nature of impression materials are used). Then the imprint of a patient’s dentition and surrounding structures of oral cavity will be left.

II. Dental Impression Trays Uses

In modern dentistry, dental impression trays are common dental products and designed to carry, confine and control the impression materials and be placed into the patients' mouth for impression making. Then it supports the mouth in the correct position in the process of hardening. That’s to say, support the impression materials in the planned contact with oral tissues and when the impression materials are removed from the mouth so that a cast can be poured. They are usually perforated to easier carry the impression materials.

In the process of impression making, the dental impression tray assists in inserting and removing impression materials from patient’s mouth.

The making of dental impressions means to create a close replica of the teeth or oral tissue, or both. Metallic impression trays or non-metallic trays need to comfortably fit into your teeth and gums and inserted into the mouth during dental treatment.

The plastic dental impression trays can be molded for the top teeth, bottom teeth, or both.

The impression trays can be made of stainless steel, aluminum or plastic in various types and sizes. 

III. What are the types of impression tray?

In accordance with different classification standards, impression trays are available in a variety of types.

Classification Standards	Types
Material used to fabricate the trays	1. Metallic trays (stainless steel, aluminum) 2. Non-metallic trays (plastic trays, acrylic resin trays)
Method of fabrication of trays	1. Stock trays: - Full arch trays - Sectional trays - Quadrant trays  2. Custom trays or Special trays
The teeth present /absent in mouth	1. Edentulous trays 2. Dentulous trays
Method of interlocking of material	1. Perforated trays 2. Non-perforated trays 3. Rim-lock trays (Water-cooled; Non water-cooled)

 

IV. Comparison of Metal Impression Trays and Plastic Impression Trays

The metal trays are strong and durable, providing maximum support for impression materials. They can be suitable for the properties of all elastometric materials.

The plastic dental impression trays are disposable ones to prevent cross-contamination. But they need to keep its shape throughout the impression procedure and pouring of impression.

V. Dental Impression Trays Sizes

There’re 10 sizes that are well known to dentists or nurses.

#1 Large Upper

#2 Large Lower

#3 Medium Upper

#4 Medium Lower

#5 Small Upper

#6 Small Lower

#7 Quadrant Upper Right Lower Left

#8 Quadrant Upper Left Lower Right

#9 Anterior Upper

#10 Anterior Lower

VI. Parts of Impression Tray

6.1 Overview of Parts of Impression Tray

The impression tray is made of 2 main parts: handle and body (flanges and floor).

6.2 Functions of Handle

The design of handle of impression tray is very practical and useful. The functions of handle benefit a lot, for instance:

It can hold the lip during impression making.

When you try to load, place or orientate the custom trays in the patient’s mouth, it’s a prefect solution to many problems. In addition, it can work as finger rest, make the impression tray stable and distribute the pressure.

The handle of impression tray should be angulated for stable grip, in terms of safety during dental procedures.

VII. How do you choose an impression tray?

The purpose of impression tray determines what impression tray should be used to individually fit patient’s oral structures. It’s necessary to choose the right impression tray, as the wrong one may cause potential injuries to patients during dental impression procedures.

There’re some common features that good dental impression trays should share.

Stability: The impression tray should be rigid and strong in use.

Extension: The impression tray needs to simulate the finished denture in the right size and shape and has enough extension to meet the requirements of impression for a variety of oral structures.

Retention: The impression tray should retain its shape throughout the impression procedure and pouring of impression.

Smooth and rounded edges: The edges of impression tray should be smooth and rounded, preventing patient’s oral cavity from being injured.

Angulated handle: The handle of the impression tray should be angulated and integral.

Reusability or disposable: Metallic trays made of stainless steel or aluminum are designed for repeated uses and should withstand autoclave sterilization for many times.

Non-metallic trays like disposable plastic ones, however, are recommended to be disposed immediately after single use.

The shape of the dental impression tray will be selected in accordance with which part of patient oral cavity should be handled.

VIII. Sterilization of Impression Trays

Impression metallic trays (stainless steel or aluminum) should be cleaned and sterilized properly before use, for the sake of hygiene and safety. Sterilization can be done in different methods, like autoclaving, dry heat or chemical vapors.

For the sake of patients’ health, the sterilization procedure should be strictly done in accordance with standard dental procedures by dental professionals, which is basic but essential in dental practices.

IX. Dental Impression Trays Suppliers

For professional dental impression trays suppliers, they usually have dental impression trays of all sizes and types in stock. Moreover, they have the design and manufacturing capacity to meet the requirements from a variety of clients worldwide. Among these professional suppliers, SKYCARE is a reputed manufacturer of qualified dental impression trays, as well as other dental products, like cheek retractors, mixing accessories, evacuation products, dental dispensers, and so on.