View the CAT printer-friendly / share this CAT
Title Using Single Arch Plastic Stock Trays Results in Greater Distortion in Dental Casts than Custom Trays
Clinical Question When fabricating dental casts, do single use plastic stock trays cause more distortions in dental casts as compared to custom trays?
Clinical Bottom Line When fabricating dental casts, using single-use plastic stock trays to take impressions cause more distortion in casts than custom trays. For practitioners making impressions, the use of custom trays result in less distortion than single-use plastic stock trays. This is supported by in vitro comparative studies in which custom trays out-performed single-use stock trays significantly. Use of custom trays is within the capability of the average general dental practice and likely to be accepted by the average patient.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 12644799Burns / 200327 castsIn vitro comparative study
Key resultsAll 9 impressions were taken of an aluminum typodont using Polyether impression material. There was more discrepancy in the casts created from stock trays compared with the casts created from the custom trays. (P< 0.001)
#2) 8957875Rueda / 199690 dental castsIn vitro comparative study
Key results90 casts created from three different impression material groups that were each divided into two groups of stock tray use and custom try use. There was more discrepancy in the casts created from stock trays compared with the cast created from the custom trays, but the difference may not be clinically significant. (no reported exact p value)
#3) 9781870Millstein / 199840 dental castsIn vitro comparative study
Key results40 casts were made from 4 different types of trays, 10 impressions each using light and heavy viscosity of Reprosil. There was a statistically significance difference between the stock trays and the custom trays, with the custom trays producing more accurate casts. (P<0.001)
Evidence Search Stock Trays, Dental, Custom
Comments on
The Evidence
The studies that were evaluated were in vitro studies, which are low quality evidence due to the external validity of the results. These studies have shown that using stock trays versus custom trays will result in more discrepancy in the casts. Burns et al. and Rueda et al. poured each impression three times. Burn et al. did not, however, address whether they used adhesive on their trays; this, as well as pouring the impressions several times, could have affected the results. While it is expected that more discrepancies occurred with stock trays, it is unclear whether these are clinically significant. Although it was established that using stock trays versus custom trays can lead to more discrepancies in the cast, more research needs to be done to determine the clinical significance. I believe that the type of tray used to make impressions does matter, but there are many other factors to take into account that could potentially affect the cast.
Applicability Dental clinicians rely on the accuracy of dental casts for reasons such as diagnosis, treatment planning, treatment pre-work and fabrication of dental prostheses. It is important that dental clinicians know that they are sacrificing the opportunity to obtain more accurate casts when using stock trays instead of custom trays.
Specialty/Discipline (General Dentistry) (Prosthodontics) (Restorative Dentistry)
Keywords Stock, trays, dental, custom
ID# 3518
Date of submission: 12/05/2022spacer
E-mail dudash@livemail.uthscsa.edu
Author Alexis DuDash, DDS
Co-author(s) Thomas O’Connor, D.M.D.
Co-author(s) e-mail oconnort@livemail.uthscsa.edu
Faculty mentor/Co-author Soo Cheol Jeong, DDS, MS, FACP
Faculty mentor/Co-author e-mail Jeongs2@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
post a rationale
None available
Comments and Evidence-Based Updates on the CAT
post a comment
None available

Return to Found CATs list