A Novel in-Vitro Visualisation and Quantification Approach for Denture Adhesives

Objectives: The increasing age of the global population means that the use of removable dental prostheses is becoming more prevalent, both to maintain normal oral functionality and aesthetic appearance. Denture adhesives can be used to improve the retention, stability and function of the prostheses. The objective of this study was to use X-ray computed tomography (XCT) to visualise and quantify the functional attributes of adhesive products in supporting denture wearers.
Methods: Denture adhesive was applied as per product label instructions. Hydrated samples were obtained by placing the denture with adhesive in deionised water for 1h at room temperature in static conditions. Full dentures (upper and lower) with a simulated gum were scanned (40μm voxel size, 80kV, Xradia 520, Zeiss, USA). The adhesive and gap in the reconstructed datasets were manually segmented and their volume and thickness were computed using Avizo (Thermo Fisher Scientific).
Results: XCT imaging generated high resolution scans of the denture and adhesive in the dry and hydrated state, without the requirement of additional contrast agents. The novel method facilitated the visualisation of the gap between a well-fitting upper denture and artificial gum as well as analyse differences in gap thickness (10-600μm) across the contours of the denture-gum surfaces and an overall gap volume of 717mm³.
A higher degree of swelling was observed for Commercial Adhesive A (42%) containing a highly hydrophilic polymer, compared to Commercial Adhesive B (22%) when hydrated. The porosity of both adhesives was also seen to increase from 21% in the dry state to 24-25% when hydrated.
Conclusions: XCT represents a novel technique capable of clearly demonstrating adhesive properties which may contribute to known functional benefits of adhesive products, namely food seal and cushioning. Future work could look at changes in the gap size and behaviour of adhesive in the gap in a dynamic setup.