Author: Asst. Lecturer Basim Kareem Nasir

Introduction:
Adhesion is the process by which two different surfaces stick together through physical or chemical forces. In dentistry, adhesion plays a critical role in restorative treatments, especially in bonding dental materials to tooth structures.

Definition:
Adhesion in dentistry refers to the chemical and micromechanical attachment between restorative materials (such as composites, sealants, or cements) and the natural tooth structure (enamel and dentin).

Mechanism:

1. Micromechanical Retention: Adhesive penetrates into the rough surface of etched enamel or dentin, creating micro-tags that hold the material.


2. Chemical Bonding: Some adhesives form chemical bonds with hydroxyapatite or collagen in dentin.



Steps in Adhesive Dentistry:

Tooth surface preparation (etching with acid).

Application of primer to improve wetting.

Placement of adhesive resin.

Bonding of restorative material.


Advantages of Adhesion:

Preserves tooth structure (less need for mechanical retention).

Provides strong bond and reduces microleakage.

Improves esthetics and longevity of restorations.

Enhances patient comfort by sealing dentin tubules, reducing sensitivity.


Applications:

Composite restorations.

Veneers and crowns.

Orthodontic brackets.

Pit and fissure sealants.


Conclusion:
Adhesion in dentistry revolutionized modern restorative techniques by allowing conservative, esthetic, and durable treatments. Continuous advancements in adhesive systems are improving the strength and reliability of dental restorations.