J Korean Acad Prosthodont.  2020 Jul;58(3):177-184. 10.4047/jkap.2020.58.3.177.

Tensile bond strength of chairside reline resin to denture bases fabricated by subtractive and additive manufacturing

• Kim HS
• Jung JH
• Bae JM
• Kim JM
• Kim YL

• KMID: 2504684
• DOI: http://doi.org/10.4047/jkap.2020.58.3.177

Abstract

Purpose
The purpose of this study was to compare and evaluate the tensile bond strength of chairside reline resin to denture base resin fabricated by different methods (subtractive manufacturing, additive manufacturing, and conventional heat-curing).
Materials and methods
Denture base specimens were fabricated as cuboid specimens with a width of 25 mm × length 25 mm × height 3 mm by subtractive manufacturing (VITA VIONIC BASE), additive manufacturing (NextDent Base) and conventional heat-curing (Lucitone 199). After storing the specimens in distilled water at 37°C for 30 days and drying them, they were relined with polyethyl methacrylate (PEMA) chairside reline resin (REBASE II Normal). The subtractive and additive manufacturing groups were set as the experimental group, and the heat-curing group was set as the control group. Ten specimens were prepared for each group. After storing all bound specimens in distilled water at 37°C for 24 hours, the tensile bond strength between denture bases and chairside reline resin was measured by a universal testing machine at a crosshead speed of 10 mm/min. The fracture pattern of each specimen was analyzed and classified into adhesive failure, cohesive failure, and mixed failure. Tensile bond strength, according to the fabrication method, was analyzed by 1-way ANOVA and Bonferroni’s method (α =.05).
Results
Mean tensile bond strength of the heat-curing group (2.45 ± 0.39 MPa) and subtractive manufacturing group (2.33 ± 0.39 MPa) had no significant difference (P>.999). The additive manufacturing group showed significantly lower tensile bond strength (1.23 ± 0.36 MPa) compared to the other groups (P<.001). Most specimens of heat-curing and subtractive manufacturing groups had mixed failure, but mixed failure and adhesive failure showed the same frequency in additive manufacturing group.
Conclusion
The mean tensile bond strength of the subtractive manufacturing group was not significantly different from the heat-curing group. The additive manufacturing group showed significantly lower mean tensile bond strength than the other two groups.

Keyword

Computer-aided design/Computer-aided manufacturing (CAD/CAM); Denture base; Denture liners; Denture rebasing; Tensile bond strength