This study aims to assess and compare the accuracy of complete arch digital implant impressions, both with and without the use of a modular E-chain for splinting scan bodies.

In contemporary prosthodontics, precise implant impressions are crucial for the long-term success of implant-supported prostheses. Digital impression techniques using intraoral scanners offer advantages over traditional methods in terms of ease and accuracy. Splinting of impression copings or scan bodies is a recognized technique to enhance stability and accuracy, especially for complete arch impressions involving four or more implants. While various materials have been used for splinting, modular chains have emerged as a promising alternative due to their ease of use, stability, and ability to improve scanning reference points, overcoming limitations of traditional resins and dental floss.

The study will involve patients visiting the Department of Oral Implantology. Patients meeting specific inclusion criteria, such as having full arch implants with an ISQ value greater than or equal to sixty, will be selected. Exclusion criteria include patients with limited mouth opening.

The methodology involves three main steps:

1. Master Reference Model Preparation: A conventional impression will be taken, and a master cast will be created. This cast will be indirectly scanned using a laboratory scanner to generate a highly accurate Standard Tessellation Language (STL) file, serving as the master reference.
2. Intraoral Scanning Procedure: Patients will undergo two intraoral scans using a Dentsply Sirona Primescan. First, scan bodies will be scanned without the modular E-chain. Second, the scan bodies will be passively connected with the modular E-chain and then scanned. Two separate STL files will be obtained from these scans.
3. Data Processing and Accuracy Assessment: All generated STL files (from scans with and without the modular E-chain) will be aligned with the master reference STL file using Geomagic Studio 12 software. The software will then be used to measure and compare the linear deviations in the x, y, and z axes (in micrometers) and angular deviations (in degrees) between the scanned models and the master reference.

The primary objective is to determine if there is a significant difference in linear and angular deviation between digital implant impressions taken with and without modular E-chain splinting. The research hypothesis anticipates a difference, while the null hypothesis states there will be no difference. An independent Student’s t-test will be used for statistical analysis, with a p-value less than 0.05 indicating statistical significance. The total sample size will be six patients, calculated based on previous research.