# In Vitro Comparison of the Dimensional Accuracy of Implant Impressions Using Custom Acrylic Trays and Prefabricated Self-Perforating Trays: Protocol for a Comparative Evaluation Study

## TL;DR

This study compares the accuracy of two types of trays used to make dental implant impressions in a lab setting.

## Contribution

The study introduces a comparative evaluation of prefabricated self-perforating trays versus custom acrylic trays for implant impressions.

## Key findings

- The dimensional accuracy of implant impressions will be evaluated using HyperMesh software.
- Statistical analysis will determine if there is a significant difference in accuracy between the two tray types.
- Results may influence clinical practices by identifying a more practical and accurate tray option.

## Abstract

The accurate transfer of implant positions from the patient’s mouth to the laboratory is crucial for the successful fabrication of prostheses in implant-based prosthodontics. Making an implant impression is a crucial part of this procedure as it replicates the intraoral implant position and transfers it to the cast to be used in the laboratory for fabricating a passive fit prosthesis. The purpose of this study is to compare and assess the accuracy of implant impressions made with prefabricated self-perforating trays and custom acrylic trays.

The primary objective is to compare the dimensional accuracy of implant impressions made using custom acrylic trays versus prefabricated self-perforating trays in an in vitro setting. The secondary objective is to determine whether the impressions made with prefabricated self-perforating trays achieve clinically acceptable accuracy.

A partially edentulous mandibular model with implants placed at the second premolar and first molar region will function as a master model. Impressions will be made using the custom acrylic tray and prefabricated self-perforating implant impression tray. The cast obtained will be scanned, and an STL file will be generated to evaluate the accuracy of implant positions using HyperMesh software. Statistical analysis will be done with IBM SPSS Statistics at a 95% CI and 80% power.

The study aims to evaluate whether there is a statistically significant difference in the accuracy of implant casts obtained using prefabricated self-perforating trays versus custom acrylic trays. As of July 2025, the models have been prepared for further analysis. It is projected that data collection will be completed in May 2026, with results to be published in early 2027.

For the success of implant dentistry, the precise fit of the final prosthesis has become a necessity. A mismatched framework may overload the implant, endangering its durability. To achieve a precise fit of the implant framework, a precise definitive cast is necessary, which depends on several factors, one of them being the implant impression tray selection. Traditionally, custom acrylic trays have been used. However, they are impractical to use in routine clinical practice due to certain disadvantages. A newer range of trays for the open tray impression technique is being marketed, and one would be able to reduce the additional expense and laboratory time associated with using custom acrylic trays by using this newer variety of self-perforating implant impression tray.