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Class V fillings address cavities at the cervical region of the tooth — the neck area at and just below the gumline. These lesions are clinically distinct from decay on biting surfaces (Class I) or between teeth (Class II) in their causes, the tissue they affect, the challenges of placing the restoration, and the materials best suited to them. Understanding these differences helps patients make sense of why their dentist recommends specific materials and techniques for this type of decay.
Why Cervical Lesions Are Different
The cervical region of the tooth is where enamel transitions to cementum — a softer, less mineralised covering on the root surface. Cementum is only 20–50 micrometres thick compared to up to 2.5mm of enamel on the crown. When gum recession exposes the cementum, it is highly vulnerable to: bacterial acid attack from plaque that accumulates readily at the gumline; mechanical wear from toothbrushing (particularly with medium or hard bristles and high pressure); and chemical erosion from acidic foods, drinks, or gastric acid reflux.
The result is that cervical lesions often involve a combination of mechanisms — erosion thinning the cementum, bacteria exploiting the weakened surface, and abrasion contributing to tissue loss. Managing only the cavity without addressing the contributing factors (brushing technique, diet, reflux) leads to recurrence at the margins of the restoration. For patients whose Class V lesions are accompanied by exposed root surfaces or gum disease, the periodontal assessment should precede the restorative appointment.
The Moisture Control Challenge
Composite resin achieves its strength through adhesive bonding to the tooth surface. Bonding requires a clean, dry surface — even a thin film of saliva or sulcular fluid contaminating the preparation before the composite is placed significantly reduces bond strength. Cervical lesions sit at and below the gumline, where gingival crevicular fluid seeps out constantly and saliva pooling is difficult to control, even with the best isolation technique.
This is why material choice matters as much as technique for Class V restorations. Composite resin in ideal conditions (excellent isolation, rubber dam) provides excellent aesthetics and acceptable longevity. Glass ionomer cement (GIC) and resin-modified glass ionomer (RMGI) bond chemically to the tooth structure through an ionic mechanism that is less disrupted by moisture — making them more reliable in the wet cervical environment, and releasing fluoride that provides ongoing protection at the restoration margin.
Material Selection at Dazzle
Nanofill composite resin: Used where isolation is achievable, the lesion is on the facial aspect of an aesthetic tooth, and colour match is the priority. Bonded with a three-step adhesive protocol (phosphoric acid etch, primer, bond) under rubber dam isolation where feasible. Provides superior aesthetics but is more technique-sensitive than GIC options.
Glass ionomer cement (GIC): Used for non-aesthetic posterior cervical lesions, patients with high caries risk (the fluoride release provides margin protection), root surface lesions where enamel is entirely absent, and elderly patients or those where moisture control is particularly difficult. Less translucent than composite but more forgiving in challenging moisture conditions.
Resin-modified glass ionomer (RMGI): Combines the moisture tolerance and fluoride release of GIC with improved aesthetics and wear resistance from the added resin component. A good compromise material for cervical lesions where both moisture control difficulty and some aesthetic requirement exist. Used frequently at Dazzle for posterior Class V restorations in patients with active caries or exposed root surfaces.
The Procedure
Cervical lesion preparation at Dazzle follows a minimally invasive approach: no more tooth structure is removed than is necessary to access the decayed tissue and create a cleanable surface for the restoration. The affected area is cleaned and the decay removed. For composite, the surface is etched and bonded in stages. For GIC or RMGI, conditioning with polyacrylic acid prepares the surface for chemical bonding.
The restoration is placed in increments, contoured to the natural tooth shape, and finished. The gingival margin is the most critical area to finish well — excess material at the margin causes gum irritation and plaque accumulation. Post-placement bite check and polishing complete the procedure.
Addressing the Cause
At the same appointment, technique review is conducted: how is the patient brushing, with what pressure, and with which brush. Toothbrushing technique modification — using the Bass technique, a soft-bristled brush, and reduced lateral scrubbing force — significantly reduces the abrasive component of cervical lesion development. Dietary counselling for patients with high acidic intake or GERD referral where gastric acid is contributing are part of the clinical discussion. A restoration placed without addressing the cause is a restoration that will need to be replaced.
FAQs
Q1: Will the filling be visible at the gumline?
For anterior and premolar Class V restorations, nanofill composite shade-matched to the tooth is used where isolation permits. The restoration is typically not visible in normal conversation. For posterior molars, aesthetics are less critical and GIC or RMGI may be selected for their functional advantages.
Q2: Why did my Class V filling fall out?
The most common causes are: moisture contamination during placement reducing bond strength; the ongoing mechanical forces (brushing, clenching) at the site exceeding the restoration’s resistance; and marginal gap formation when the original lesion cause was not addressed. At Dazzle, we assess why previous restorations failed before placing a new one, to avoid repeating the same outcome.
Q3: Is fluoride from glass ionomer significant?
Yes, clinically. GIC releases fluoride into the tooth structure and surrounding saliva, increasing enamel and dentine resistance to bacterial acid attack. This is particularly valuable at the restoration margin — the area where recurrent decay is most likely to develop. For high-caries-risk patients, the fluoride release from GIC provides meaningful long-term protection beyond the restoration itself.
Q4: Do I need an injection for a Class V filling?
Often, topical anaesthetic alone is adequate for shallow cervical lesions. Where dentine exposure is significant or the lesion is deep, local infiltration anaesthesia provides complete comfort during preparation. The cervical region is less sensitive than the pulp chamber area, so anaesthesia requirements are typically lower than for deeper restorations.
