# Hybrid Digital Workflow for Accurate Distal Extension Reproduction in Free-End Removable Dental Prosthesis: A Technical Report

## TL;DR

This paper introduces a new digital workflow for making dental prostheses that improves accuracy and reduces the need for traditional techniques.

## Contribution

The novel hybrid workflow combines plaster-cast scanning with intraoral scanning to enhance accuracy in distal extension dental prostheses.

## Key findings

- The hybrid workflow produces more accurate models of the distal extension region compared to direct intraoral scanning.
- Digitally capturing mobile mucosa morphology eliminates the need for the traditional altered-cast technique.
- The method reduces clinical time, technical sensitivity, and material costs.

## Abstract

Background/Objectives: This technical report introduces an innovative hybrid digital workflow that integrates diagnostic plaster-cast scanning with intraoral scanning to produce an accurate 3D-printed model for fabricating distal-extension removable dental prostheses (RDPs). Methods: The technique aims to overcome the challenges of reproducing the mobile mucosa in free-end saddles, a critical factor for denture base accuracy and stability. The workflow began with conventional clinical procedures, including clinical examination, impression-making, and cast surveying. After performing the required mouth preparations according to the prosthetic design, the diagnostic cast was digitized and selectively modified to allow intraoral rescanning. The prepared teeth were then scanned intraorally and merged with the digitalized cast, producing a refined virtual model for CAD-based metal framework design. The framework was digitally designed, 3D-printed to verify adaptation, and cast in cobalt–chromium. Standard RDP fabrication steps were followed, including intraoral framework try-in, fabrication of acrylic bases, occlusal registration, tooth arrangement, and functional and esthetic try-in. The final prosthesis was installed and adjusted without the need for an additional impression. Results: This hybrid workflow enabled a highly accurate reproduction of the distal extension region, outperforming models derived solely from direct intraoral scanning. By digitally capturing the physiological morphology of the mobile mucosa, the method eliminates the need for the traditional altered-cast technique, reducing clinical time, technical sensitivity, and material costs. Conclusions: The proposed approach enhances denture base accuracy, improves adaptation, and promotes more uniform occlusal load distribution in free-end RDPs. This streamlined and reproducible digital protocol offers a clinically relevant advancement, with potential to improve prosthesis stability and long-term outcomes.