J Korean Acad Prosthodont.  2021 Jan;59(1):18-26. 10.4047/jkap.2021.59.1.18.

Comparative study of volumetric change in water-stored and dry-stored complete denture base

• Kim J
• Lee Y
• Hong SJ
• Paek J
• Noh K
• Pae A
• Kim HS
• Kwon KR

• KMID: 2511644
• DOI: http://doi.org/10.4047/jkap.2021.59.1.18

Abstract

Purpose
Generally, patients are noticed to store denture in water when removed from the mouth. However, few studies have reported the advantage of volumetric change in underwater storage over dry storage. To be a reference in defining the proper denture storage method, this study aims to evaluate the volumetric change and dimensional deformation in case of underwater and dry storage. Materials and
methods
Definitive casts were scanned by a model scanner, and denture bases were designed with computer-aided design (CAD) software. Twelve denture bases (upper 6, lower 6) were printed with 3D printer. Printed denture bases were invested and flasked with heat-curing method. 6 upper and 6 lower dentures were divided into group A and B, and each group contains 3 upper and 3 lower dentures. Group A was stored dry at room temperature, group B was stored underwater. Group B was scanned at every 24 hours for 28 days and scanned data was saved as stereolithography (SLA) file. These SLA files were analyzed to measure the difference in volumetric change of a month and Kruskal-Wallis test were used for statistical analysis. Best-fit algorithm was used to overlap and 3-dimensional color-coded map was used to observe the changing pattern of impression surface.
Results
No significant difference was found in volumetric changes regardless of the storage methods. In dry-stored denture base, significant changes were found in the palate of upper jaw and posterior lingual border of lower jaw in direction away from the underlying tissue, maxillary tuberosity of upper jaw and retromolar pad area of lower jaw in direction towards the underlying tissue.
Conclusion
Storing the denture underwater shows less volumetric change of impression surface than storing in the dry air.

Keyword

Computer-aided design; Denture base; Polymethyl methacrylate