Occlusal accuracy of digitally manufactured removable dentures: a systematic review of in vitro studies

Abstract

Objective

To evaluate the occlusal accuracy of digitally manufactured removable dentures compared to conventional fabrication, and to identify key influencing factors.

Methods

A comprehensive literature search of Ovid MEDLINE(R), Scopus, and Web of Science (All Databases), was conducted up to December 2024, supplemented by manual searches in reference lists and Google Scholar. Eligible studies were peer-reviewed, published in English, available in full text, and investigated the occlusal accuracy of digitally manufactured removable dentures in vitro. Studies were excluded if they lacked a method to assess the accuracy of denture teeth, tooth sockets, or occlusal surfaces. Risk of bias was evaluated with the Quality Assessment Tool For In Vitro Studies.

Results

Twenty-one studies met inclusion criteria. Digitally manufactured removable dentures, particularly subtractively manufactured dentures, demonstrated superior occlusal accuracy compared to conventional dentures. Additive manufacturing showed promising results but was influenced by layer thickness (100 µm outperformed 50 µm in DLP, whereas 50 µm was superior in SLA), build orientation (0° outperformed 90°, which outperformed 45°), and post-processing protocols (post-curing of dentures on casts). Optimal denture base-tooth offset values (0.05–0.25 mm, tooth-type dependent), tooth basal shapes (projections/dimples), and monolithic designs enhanced accuracy, while teeth positioning keys did not improve outcomes. Methodological heterogeneity, including variations in specimen shapes and measurement techniques, was noted.

Conclusions

Digital workflows, especially subtractive manufacturing, offer significant advantages in enhancing the occlusal accuracy of removable dentures. Key factors such as design schemes, manufacturing parameters, post-processing protocols, and bonding strategies critically influence outcomes. Standardized research methodologies are needed to facilitate cross-study comparisons. Future studies should explore the impact of palatal morphology, specimen pre-treatment, post-washing parameters, and the accuracy of digitally manufactured removable partial dentures.

Clinical Significance

Digital removable dentures have superior occlusal accuracy compared to conventionally made dentures. Standardized workflow and analysis method for occlusal accuracy need further study and development to provide clinically relevant information to dental practitioners.