J Adv Prosthodont.  2018 Oct;10(5):361-366. 10.4047/jap.2018.10.5.361.

Effects of relining materials on the flexural strength of relined thermoplastic denture base resins

• Sun Y
• Song SY
• Lee KS
• Park JH
• Ryu JJ
• Lee JY

• KMID: 2422872
• DOI: http://doi.org/10.4047/jap.2018.10.5.361

Abstract

PURPOSE
The aim of this study was to evaluate the effects of relining materials on the flexural strength of relined thermoplastic denture base resins (TDBRs).
MATERIALS AND METHODS
For shear bond strength testing, 120 specimens were fabricated using four TDBRs (EstheShot-Bright, Acrytone, Valplast, Weldenz) that were bonded with three autopolymerizing denture relining resins (ADRRs: Vertex Self-Curing, Tokuyama Rebase, Ufi Gel Hard) with a bond area of 6.0 mm in diameter and were assigned to each group (n=10). For flexural strength testing, 120 specimens measuring 64.0×10.0×3.3 mm (ISO-1567:1999) were fabricated using four TDBRs and three ADRRs and were assigned to each group (n=10). The thickness of the specimens measured 2.0 mm of TDBR and 1.3 mm of ADRR. Forty specimens using four TDBRs and 30 specimens using ADRRs served as the control. All specimens were tested on a universal testing machine. For statistical analysis, Analysis of variance (ANOVA) with Tukey's test as post hoc and Spearman's correlation coefficient analysis (P=.05) were performed.
RESULTS
Acry-Tone showed the highest shear bond strength, while Weldenz demonstrated the lowest bond strength between TDBR and ADRRs compared to other groups. EstheShot-Bright exhibited the highest flexural strength, while Weldenz showed the lowest flexural strength. Relined EstheShot-Bright demonstrated the highest flexural strength and relined Weldenz exhibited the lowest flexural strength (P < .05). Flexural strength of TDBRs (P=.001) and shear bond strength (P=.013) exhibited a positive correlation with the flexural strength of relined TDBRs.
CONCLUSION
The flexural strength of relined TDBRs was affected by the flexural strength of the original denture base resins and bond strength between denture base resins and relining materials.

Keyword

Thermoplastic resin; Denture bases; Denture liners; Bond strength; Flexural strength

MeSH Terms

Denture Bases*
Denture Liners
Denture Rebasing
Dentures*

Figure

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  Fig. 1 Specimen for shear bond strength testing.

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  Fig. 2 Specimens for flexural strength testing. (A) Denture base resin with dimensions of 64.0 × 10.0 × 3.3 mm. (B) Trimmed denture base resin with dimensions of 64.0 × 10.0 × 2.0 mm.

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  Fig. 3 Correlation coefficient. (A) Flexural strength of the denture base (X) / Relined denture base resins (Y). (B) Flexural strength of the relining materials (X) / Relined denture base resins (Y). (C) Bond strength (X) / Relined denture base resins (Y).

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