Resin/Resin bonding: a new adhesive technology.

Area of Science:

• Dental Materials Science
• Polymer Chemistry
• Surface Engineering

Background:

• Achieving durable bonds between dental composites and various resin substrates is crucial for restoration longevity.
• Existing surface treatment methods may have limitations in effectiveness or applicability to different resin types.

Purpose of the Study:

• To evaluate a novel surface treatment technique using flame application for enhancing bond strength.
• To assess the bond strength between a luting composite and light-cured, heat-cured, and thermoplastic resins.

Main Methods:

• Resin specimens (Targis, SR Isosit, Dental D) were prepared and subjected to flame treatment for varying durations (5, 10, 20 s/2 cm²).
• Methacryl silane was applied, followed by a luting composite, and shear bond strength was measured after thermocycling (5000 cycles, 5-55°C).
• Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and fracture analysis were performed; etched and silanized Empress II served as a control.

Main Results:

• The flame treatment method showed no significant difference in shear bond strength across tested durations or between Targis (light-cured) and SR Isosit (heat-cured) resins.
• Achieved bond strengths for Targis and SR Isosit ranged from 17 to 29 MPa, comparable to the control (27 MPa).
• Complete failure occurred for all Dental D (thermoplastic) specimens, rendering bond strength unmeasurable; FTIR confirmed silicon presence on treated surfaces.

Conclusions:

• The new flame-treatment technology is effective for surface-treating polymerized composite resins, promoting good bonding with luting composites.
• This surface treatment method demonstrates failure when applied to thermoplastic resins.