Non-carious cervical lesions (NCCLs) are among the most challenging cases in operative dentistry. Unlike conventional cavities caused by bacterial activity, NCCLs are primarily the result of mechanical and chemical factors. This means the cavity often appears clean and free of decay, with no need for conventional caries removal.

However, the absence of carious dentin also means there is no inherent cavity geometry for mechanical retention. In such cases, the success of the restoration depends almost entirely on the adhesive system used. Any weakness in bonding can quickly lead to restoration failure, making NCCLs a real test of your bonding protocol.

Why Bonding Is Difficult?

NCCLs typically involve dentin surfaces covered by:

1- Sclerotic dentin

2- Hypermineralized dentinal tubules

These factors significantly reduce bond strength because the adhesive cannot penetrate efficiently.
It’s important to remember:

1- Bond strength is weaker in sclerotic dentin and primary teeth.

Surface Preparation: The Key to Successful Bonding

To enhance bond strength and overcome these challenges, surface roughening is essential.
Recommended methods include:

1- Diamond bur

2- Abrasive disk

Benefits of roughening:

1- Exposes fresh dentin for better adhesive penetration.

2- Removes the sclerotic surface layer.

3- Increases micromechanical retention.

Sandblasting: Pros and Cons

While sandblasting can increase surface roughness, it may also block dentinal tubules with abrasive particles, reducing retention in some cases.
A 2008 micro-CT study found that sandblasting particles could occlude tubules, requiring a subsequent acid etch to reopen them.

Diamond bur preparation, on the other hand, roughens the surface safely and effectively without the risk of particle blockage.

Outdated Retention Grooves: A Controversial Practice

In the past, creating retention grooves in NCCLs was common to increase retention.
While effective mechanically, this approach sacrifices tooth structure unnecessarily, especially when we now have better bonding techniques that preserve enamel and dentin.

The Importance of Beveling

Beveling is highly recommended in NCCL restorations because it:

1- Improves aesthetics by blending composite margins.

2- Increases the adhesive surface area.

Don’t Forget the Cause

Restoration alone is not enough.
Identify and address the underlying cause to prevent recurrence:

1- Occlusal overload (check for high spots, bruxism)

2- Parafunctional habits (nail biting, pen chewing)

3- Stress-related abfraction

A clinical case of  Non-Carious Cervical Lesions (NCCLs)

Conclusion

NCCLs demand a precise and informed approach.
By understanding the substrate challenges, using proper surface preparation, and applying effective adhesive techniques, you can significantly improve restoration longevity. Always remember to address the causative factor to ensure lasting success.

References:

• Composite restoration placed in non-carious cervical lesion: which cavity preparation is clinically reliable?

• Non-carious cervical lesions: morphology and progression, prevalence, etiology, pathophysiology, and clinical guidelines for restoration.