Cervical (abfraction) defects: why a notch appears at the gumline

Key points

• A cervical defect is tissue loss at the neck of the tooth, wedge- or step-shaped.
• It is a non-carious lesion: bacteria are not the cause, so a filling placed without addressing the cause does not solve it.
• The common complaint is sensitivity to cold, to acid and to brushing.
• Contributing factors include occlusal overload, a hard brush with abrasive paste, and gum recession.
• Surface preparation before restoration matters particularly here: a filling at the neck carries a bending load.

How to use this guide

• First distinguish a cervical defect from decay, erosion and gum recession during an examination.
• Ask for the bite, brushing technique, toothpaste and gum condition to be assessed separately; several factors often act together.
• Compare monitoring, sensitivity control, load correction and restoration according to the depth of the defect and your symptoms.

What it looks like and what it feels like

A notch with fairly sharp edges appears at the neck of the tooth, at the gum margin — wedge- or step-shaped. It is most often seen on canines and premolars.

What patients usually notice first is not the defect but the sensitivity: a reaction to cold, to acid, or to the touch of a brush. In the exposed area dentine lies closer to the surface than it does under enamel.

Why this is not decay

In caries, bacteria destroy tissue. A cervical defect is classed as non-carious: the tissue is not softened but lost, and the surface stays firm and smooth.

The difference matters for treatment. With caries it is enough to remove the affected tissue and rebuild the tooth. Here, if the cause of the loss is not identified, the restoration will chip and the defect will reappear beside it.

What is considered as the cause

Occlusal overload: where bite forces are distributed unevenly, bending stresses arise at the neck — the thinnest part of the enamel.

Mechanical wear: a hard brush, heavy pressure and abrasive pastes accelerate loss in an already weakened area.

Gum recession: as the gum margin drops, the neck is exposed to both load and brushing.

Usually more than one factor is at work, so the bite, brushing technique and gum condition are assessed together.

How it is treated

A small defect without marked sensitivity may be monitored, with brushing technique corrected and a suitable paste chosen — sometimes that is enough for the loss to stop.

A pronounced defect is restored. A filling at the neck works in awkward conditions: it carries bending forces and sits close to the gum, so the quality of its bond to the tissue is critical.

Surface preparation before bonding matters especially. Cervical defects are one of the situations where preparation without a bur is possible: the tissue is firm and does not need removing, only cleaning and conditioning so the adhesive can grip.

Where overload is the cause, adjusting the bite is considered separately. Without it, the restoration works against the same force that created the defect.

Questions to ask at your consultation

• Which findings show that this is a cervical defect rather than decay?
• Does the defect need restoring now, or are monitoring and care changes enough?
• What may be overloading this tooth and how can the risk of another restoration fracture be reduced?

Frequently asked questions

Will a cervical defect heal by itself?

No. Lost tooth tissue does not regenerate. But the loss can be stopped if what causes it is addressed.

Why do fillings at the neck keep chipping?

That area carries bending forces when the teeth meet. If the cause of the overload remains, the same force acts on the restoration. This is why the bite is assessed alongside the filling.

Can this be treated without drilling?

With cervical defects, often yes. The tissue is firm and does not need removing; what is needed is surface preparation before bonding, which air abrasion can provide.

Does toothpaste for sensitive teeth help?

It may reduce sensitivity, but it does not restore lost tissue or remove the cause of the loss. It is support, not treatment.

Sources used to prepare this guide

Content updated: 2026-08-01

• Tooth wear and non-carious cervical lesions — American Dental Association, Oral Health Topics