Resin-infiltrated-dentine--a FE-ESEM microscopy investigation.

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• The hybrid layer is crucial for durable bonding between dental composites and dentine.
• Understanding the interaction of bonding systems with dentine is vital for clinical success.

Purpose of the Study:

• To evaluate the efficacy of different etchants/conditioners and dentine bonding systems in forming hybrid layers.
• To observe resin infiltration and hybrid layer formation on dentine surfaces under near-physiological conditions.

Main Methods:

• Utilized Field Emission Environmental Scanning Electron Microscopy (FE-ESEM) for high-resolution imaging.
• Examined dentine surfaces (fractured, smear layer present, smear layer removed) before and after application of four dentine bonding systems: Scotchbond 1, Optibond Solo, Prime & Bond NT, and Prompt L-Pop.
• Observed specimens under both wet and dry conditions to simulate intraoral environments.

Main Results:

• Scotchbond 1, Optibond Solo, and Prime & Bond NT demonstrated successful resin penetration into dentine tubules, forming hybrid layers.
• Prime & Bond NT occasionally resulted in a partially filled hybrid layer.
• Prompt L-Pop failed to produce a polymerised resin or observable hybrid layer.
• FE-ESEM enabled visualization of dentine-resin interactions under near-physiological wet conditions.

Conclusions:

• The choice of dentine bonding system significantly impacts hybrid layer formation.
• Scotchbond 1, Optibond Solo, and Prime & Bond NT show promise for effective dentine bonding.
• Prompt L-Pop appears inadequate for forming a hybrid layer, suggesting limitations in its application for composite bonding.