Evaluation of the F2000 bonding procedure: a high resolution SEM study

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• Dental restorative systems require effective bonding to tooth structure for longevity.
• Understanding the morphological characteristics of adhesive interfaces is crucial for predicting clinical performance.
• The F2000 Restorative System utilizes a one-step approach, while Scotchbond 1 (SB1) employs a multi-step total-etch technique.

Purpose of the Study:

• To evaluate the morphological bonding of the F2000 Restorative System to enamel and dentin using high-resolution scanning electron microscopy (SEM).
• To correlate SEM findings with tensile bond strength analysis.
• To compare the bonding performance of F2000 with a control adhesive system, Scotchbond 1 (SB1).

Main Methods:

• Teeth were prepared using F2000 PA (15s and 30s) or 35% phosphoric acid with SB1 (15s and 30s).
• Restored teeth were extracted, sectioned, and analyzed via field emission in-lens SEM (FEISEM).
• In vitro evaluation of conditioning/etching patterns on dentin disks was performed.

Main Results:

• FEISEM revealed microporosities and good resin adaptation on enamel after 30s F2000 PA application.
• F2000 PA application on dentin showed residual smear plugs, unlike the complete absence after phosphoric acid etching.
• SB1 demonstrated open tubules and resin tag formation, indicating effective etching.

Conclusions:

• The F2000 PA one-step procedure showed favorable ultra-structural bonding to enamel and dentin at 30s.
• The SB1 adhesive system, following phosphoric acid etching, yielded significantly higher bond strength values (19.0+/-4.4MPa) compared to F2000 PA (7.7+/-2.2MPa).
• While morphologically adequate, the F2000 system's bond strength was surpassed by the SB1 system.