AlQranei M S, Balhaddad A A, Melo M A S. The burden of root caries: Updated perspectives and advances on management strategies. Gerodontology 2021; 38: 136-153.

An ongoing worldwide problem.

Root caries is any carious lesion which occurs on the root surface of the tooth and is more prevalent in older people. Lesions are discoloured, softened and ill defined but may or may not be cavitated. Dentine has a higher percentage of organic material than enamel and demineralises at a higher pH (6-6.8) than enamel (5.4). Additional risk factors for root caries, in addition to the presence of carbohydrates and bacteria, include reduced ability to maintain oral hygiene and reduced salivary flow. Diagnosis is made on visual criteria and radiographically. Gentle tactile examination with an explorer may also be used with care because of the potential for damage to early lesions, thus inducing cavitation.

Restorative treatments for root caries lesions have poor prognosis due to the close proximity of the gingival margin, the difficulties of isolation and problems associated with bonding to dentine. Lesions tend to spread laterally making them shallow but extensive, and proximally, difficult to access. When necessary, resin modified glass ionomer cements are the restorative materials of choice. Composite resins and calcium silicate cements have lower survival rates. Non-invasive and preventive strategies are preferable.

Successful prevention depends on changing dietary habits, disturbing the biofilm, reducing the presence of plaque, promoting remineralisation and inhibiting demineralisation. Early intervention to prevent loss of periodontal attachment and consequent exposure of the root to the oral environment is important. As with coronal caries, reduction in the frequency of the consumption of food and snacks that are high in sugar is important. Plaque removal techniques should focus on high risk areas such as proximally and surfaces abutting a denture. Patients with xerostomia should be recommended to use xylitol containing products and saliva-inducing medications.

Fluoride has been shown to be effective in preventing root caries, either in toothpaste, in rinses or by professional topical application. Higher concentration 5000 ppm NaF dentifrices are more effective than lower concentrations. Topically applied fluoride both prevents and arrests existing lesions. The application of chlorhexidine varnish may be beneficial. The application of silver diamine fluoride has also been shown to arrest root caries lesions.

With the anticipated increase in the worldwide population of people aged over 65 from 12% to 22% by 2050, many of whom are retaining their natural dentition into old age, root caries is expected to be one of the main challenges in dentistry in the next decades.