Comparative study of luting agents with composite resin cores

Area of Science:

• Dental Materials Science
• Biomaterials Engineering

Background:

• Dental cements are crucial for prosthodontic restorations, requiring durable bonds between crown and core materials.
• Understanding the mechanical properties and longevity of different cement types under various conditions is essential for clinical success.

Purpose of the Study:

• To compare the tensile bond strengths of zinc phosphate and polycarboxylate cements used for cementing gold crowns to composite resin cores.
• To evaluate the impact of thermocycling and varied storage durations on the bond strengths of these dental cements.

Main Methods:

• Sixty composite resin cores were prepared, and gold alloy crowns were cemented using either zinc phosphate or polycarboxylate cement.
• Samples underwent storage for 1 day or 1 month, followed by thermocycling (5-55°C, 60-second dwell time) for 5, 100, or 1000 cycles, or served as non-cycled controls.

Main Results:

• Zinc phosphate cement exhibited significantly higher bond strengths than polycarboxylate cement across all conditions.
• Increased storage time prior to thermocycling led to a significant enhancement in bond strength for both cement types.
• No significant differences in bond strength were observed between varying thermocycling durations or between cycled and non-cycled control groups.

Conclusions:

• Zinc phosphate cement offers superior bonding performance compared to polycarboxylate cement for gold crowns bonded to composite resin cores.
• Extended pre-test storage duration positively influences the bond strength of both zinc phosphate and polycarboxylate cements.
• Thermocycling, within the tested parameters, did not significantly degrade the bond strength of either cement type in this study.