Dentin bond strength after air drying and rewetting

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Adhesive Dentistry

Background:

• Dentin bonding is critical for the longevity of dental restorations.
• The integrity of the dentin surface, particularly its collagenous network, influences interfacial strength.
• Understanding the effects of surface moisture on bond strength is essential for optimizing clinical procedures.

Purpose of the Study:

• To evaluate the impact of air drying and subsequent remoistening of dentin on resin composite bond strength.
• To assess the contribution of the outermost collagenous network and surface area of chemically conditioned dentin to interfacial strength.

Main Methods:

• Twelve experimental groups of caries-free human molar teeth were used.
• Shear bond strength was measured for dentin treated with All-Bond 2 and BisFil.
• Dentin surfaces were subjected to various conditions: wet control, air drying (10 and 30 seconds), and remoistening (5 seconds) after drying, with and without prior chemical conditioning (10% phosphoric acid or 5% NaOCl).

Main Results:

• Air drying dentin, especially for 30 seconds, significantly reduced shear bond strength compared to wet controls.
• Remoistening dried dentin surfaces for 5 seconds restored bond strength to levels comparable to wet controls.
• Chemical conditioning with phosphoric acid generally yielded higher bond strengths than non-conditioned surfaces, with remoistening mitigating drying effects.

Conclusions:

• Air drying dentin negatively impacts resin composite bond strength.
• Remoistening the dentin surface after drying can effectively recover lost bond strength.
• Maintaining optimal dentin moisture is vital for achieving reliable and durable adhesive interfaces in restorative dentistry.