Root Caries Treatment: Approaches for Healthier Teeth

Tooth decay affecting the roots, known as root caries, is a growing concern, especially among older adults and those with gum recession. Unlike cavities on the crown of the tooth, root caries progress quickly due to the softer nature of exposed root surfaces. Left untreated, they can lead to pain, infection, and tooth loss.

Addressing root caries requires early detection, professional intervention, and preventive strategies.

Factors Contributing To Root Lesions

Root caries develop due to biological, behavioral, and environmental factors that accelerate the breakdown of exposed root surfaces. Gingival recession is a primary contributor, exposing the root dentin, which is less mineralized and more vulnerable to acid dissolution. Studies show that once the cementum layer is lost, the underlying dentin is nearly twice as susceptible to demineralization as enamel (Featherstone, 2021). Maintaining healthy gum tissue is essential to prevent unnecessary root exposure.

Salivary composition and flow rate significantly impact root caries progression. Saliva neutralizes acids and aids remineralization through calcium and phosphate ions. Xerostomia, often caused by medications like antihypertensives, antidepressants, and antihistamines, reduces salivary flow, creating conditions favorable for acid-producing bacteria. A systematic review in the Journal of Dental Research (2022) found that individuals with chronic dry mouth had a 2.5-fold increased risk of developing root caries. This underscores the importance of interventions such as saliva substitutes or stimulants for at-risk individuals.

The microbial composition of dental plaque also plays a role. Streptococcus mutans and Lactobacillus produce lactic acid, accelerating dentin breakdown. Research indicates that root caries lesions harbor a higher proportion of acid-tolerant bacteria than coronal caries, making them harder to halt without targeted antimicrobial strategies (Takahashi & Nyvad, 2023).

Dietary habits further influence root caries risk. Frequent consumption of fermentable carbohydrates fuels acid-producing bacteria, leading to prolonged low pH levels in the oral cavity. A longitudinal study in Caries Research (2023) found that individuals consuming sugary snacks more than three times per day had a significantly higher incidence of root caries. Acidic beverages like sodas and citrus juices contribute to both direct dentin erosion and bacterial acid production, highlighting the need for dietary modifications.

Recognizing And Assessing Damage

Detecting root caries early is challenging due to their subtle presentation. Unlike coronal cavities, which often appear as dark pits, root caries typically begin as softened, discolored areas along the exposed root surface. Initially, lesions may appear yellow, brown, or black, gradually developing a leathery or tacky texture as demineralization progresses. A Journal of Clinical Dentistry (2023) study found that tactile examination with a dental explorer can distinguish active lesions, which feel soft, from arrested lesions that have a firmer consistency due to remineralization.

Advanced diagnostic tools enhance detection accuracy. Traditional bitewing radiographs help assess interproximal root caries, but lesions may not be visible until significant mineral loss occurs. Digital imaging techniques like near-infrared transillumination (NIRI) and optical coherence tomography (OCT) offer improved sensitivity. A Caries Research (2022) study found that NIRI was more effective at detecting early-stage root caries than conventional radiographs. Fluorescence-based detection systems, such as DIAGNOdent, can also identify active lesions by measuring bacterial byproducts that fluoresce under specific wavelengths.

Patient-reported symptoms provide additional clues. Early-stage lesions may not cause noticeable discomfort, but as decay progresses, sensitivity to temperature changes, particularly cold stimuli, increases. This occurs due to fluid movement within dentinal tubules, stimulating nerve endings in the underlying pulp. A clinical review in the International Journal of Oral Science (2023) suggests that persistent sensitivity or spontaneous pain may indicate lesion advancement toward the pulp chamber, requiring more aggressive intervention. If decay extends subgingivally, patients may experience localized gum tenderness or mild bleeding, complicating treatment.

Noninvasive Professional Treatments

Early-stage root caries can often be managed with noninvasive treatments that halt demineralization and promote remineralization. Fluoride application is a widely used approach, strengthening dentin and reducing bacterial acid production. High-concentration fluoride varnishes, typically containing 5% sodium fluoride (NaF), coat exposed root surfaces, forming fluorapatite, which resists acid dissolution. Clinical studies show that biannual applications of 5% NaF varnish can reduce root caries progression by up to 67% in high-risk populations.

Silver diamine fluoride (SDF) is another effective option for more advanced lesions that have not yet cavitated. This antimicrobial solution combines silver ions, which inhibit bacteria, with fluoride for remineralization. A randomized controlled trial in the Journal of the American Dental Association (2023) found that annual applications of 38% SDF halted progression in 90% of treated root lesions over two years. However, SDF permanently stains treated areas black, which may be a cosmetic concern.

Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) formulations support remineralization by acting as a reservoir for calcium and phosphate ions. CPP-ACP pastes, such as MI Paste, can be applied professionally or used at home. Research suggests that combining CPP-ACP with fluoride enhances its effectiveness. Additionally, biomimetic remineralization agents like hydroxyapatite nanoparticles show promise in filling microscopic defects in demineralized dentin.

Restorative Treatment Options

When root caries progress beyond noninvasive management, restorative interventions are necessary. The choice of restorative material is critical, as root surfaces present unique challenges. Glass ionomer cements (GICs) are preferred for root caries restorations due to their ability to chemically bond to dentin while releasing fluoride for ongoing protection. A Operative Dentistry (2023) study found that high-viscosity GIC restorations had superior retention rates in root caries lesions compared to composite resins, particularly in patients with high salivary acidity.

Composite resins offer better aesthetics but require strict moisture control during placement, as excess saliva can compromise adhesion. Advances in self-etching adhesive systems have improved composite bonding to dentin. For deep root lesions near the pulp, resin-modified glass ionomers (RMGIs) provide a balance of fluoride release and durability. RMGIs also exhibit lower polymerization shrinkage than conventional composites, reducing the risk of restoration failure in areas under occlusal stress.

Preventive Measures To Reduce Recurrence

Preventing root caries recurrence requires oral hygiene modifications, professional maintenance, and lifestyle adjustments. Since exposed root surfaces lack protective enamel, they remain vulnerable to further demineralization. Patients with a history of root caries are at higher risk for future lesions, making long-term preventive care essential.

Optimizing daily oral hygiene minimizes bacterial biofilm on vulnerable root surfaces. Using a soft-bristled toothbrush with gentle pressure helps prevent further gum recession while effectively removing plaque. Fluoride toothpaste with at least 5,000 ppm fluoride, available by prescription, significantly reduces root caries progression. Antibacterial mouth rinses containing chlorhexidine or essential oils help suppress cariogenic bacteria, particularly for individuals with recurrent lesions. Interdental cleaning with floss or interdental brushes is crucial, as root caries often develop in areas with high plaque retention.

Regular professional dental visits enable early detection of new lesions and reinforcement of protective measures. Professional fluoride applications, including varnishes or gels, provide additional defense against demineralization, particularly for patients with reduced salivary flow. High-risk individuals, such as those with chronic dry mouth or extensive restorations, may benefit from customized preventive plans incorporating salivary stimulants or dietary counseling. Maintaining consistent preventive efforts significantly lowers the likelihood of future root caries and preserves long-term oral health.