Shear Bond Strength of Two Chemically Different Denture Base Polymers to Reline Materials

• Published in: Journal of prosthodontics Vol. 18; no. 7; pp. 596 - 602
• Main Authors: Ahmad, Fauziah, Dent, MClin, Yunus, Norsiah
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.10.2009
• Subjects: Acrylic Resins - chemistry; Analysis of Variance; Composite Resins - chemistry; Dental Bonding - methods; Dental Stress Analysis; Dentistry; Denture Bases; Denture Liners; Denture Rebasing - methods; Humans; light polymerization; Materials Testing; Methacrylates - chemistry; methyl methacrylate; Methylmethacrylates - chemistry; reline; Shear bond; Shear Strength; urethane dimethacrylate
• ISSN: 1059-941X; 1532-849X
• DOI: 10.1111/j.1532-849X.2009.00481.x

Purpose: This study evaluated the shear bond strengths of light‐polymerized urethane dimethacrylate (Eclipse) and heat‐polymerized polymethylmethacrylate (Meliodent) denture base polymers to intraoral and laboratory‐processed reline materials. Materials and Methods: Thirty disks measuring 15 mm diameter and 2 mm thick were prepared for each denture base material following the manufacturers’ recommendation. They were relined with Meliodent RR, Kooliner, and Secure reline materials after 1 month of water immersion. Ten additional Eclipse specimens were relined using the same Eclipse resin. A shear bond test was carried out on an Instron machine at a crosshead speed of 1.0 mm/min 24 hours after relining. Data were analyzed using two‐way and one‐way ANOVAs and post hoc Dunnett's T3 test (p= 0.05). The nature of failure was analyzed under a stereomicroscope. The effect of dichloromethane adhesive on the two denture polymer surfaces and the failed interfaces of mixed and adhesive failures were analyzed under a SEM (scanning electron microscope). Results: Two‐way ANOVA showed significant differences in the shear bond strength values as a function of the denture base polymers, reline materials, and their interaction (p < 0.05). One‐way ANOVA showed significant differences in shear bond strength values among denture base‐reline combinations (p < 0.05) except for Meliodent‐Kooliner and Eclipse‐Meliodent RR relines. Meliodent showed the highest shear bond strength value when relined with Meliodent RR (14.5 ± 0.5 MPa), and Eclipse showed the highest value with Eclipse relining (11.4 ± 0.6 MPa). Meliodent denture base showed adhesive, cohesive, and mixed failure, while all Eclipse showed adhesive failure with various reline materials. Conclusion: The two chemically different denture base polymers showed different shear bond strength values to corresponding reline materials.