Managing early childhood caries with silver diamine fluoride in the COVID-19 context: case report

The global pandemic caused by the novel coronavirus, SARS-CoV-2, and its disease, COVID-19, is accompanied by some of the most difficult challenges in modern dentistry, and has brought along with it a need for adaptation and resiliency in clinical practice.¹ Dentistry is positioned as one of the professions with the highest risk of infection and transmission (dentist to patient and vice versa) due to the necessary use of instruments that emit aerosols in certain procedures, therefore, options that allow providing the necessary care in a safe way for all involved should be sought.^2,3 Although children are potentially asymptomatic carriers of the virus, it is our duty to continue servicing them.^4,5 As always, paediatric dentistry needs to be efficient, providing care that ensures all patients' oral health needs are met in a safe manner for all involved.^1,5

The World Health Organization (WHO) reported that early childhood caries (ECC) burdens approximately 530 million pre-school children worldwide.^6,7 This condition often progresses quickly, resulting in significative destruction of the primary dentition, therefore negatively impacting the quality of life of those affected.^8,9

The high prevalence of caries, along with and the new concerns over the potential postponement of seeking dental treatment for fear of COVID-19 infection, has obliged us to seek out efficient tools in paediatric dental care.¹⁰

Current minimally invasive techniques provide the benefit of practising with equipment that generates little or no aerosol. Silver diamine fluoride (SDF; Ag(NH₃)₂F) was introduced to the Japanese market at the end of the 1960s, and has gradually found its place as an effective cariostatic and dentine desensitizer, garnering approval by different governmental health organizations worldwide.^11,12,13 However, despite its antimicrobial, remineralizing, and disinfecting properties, the darkening effect of the silver compound on the treated surface has been a cause of concern, especially among dentists, thus potentially limiting the use of the material.¹⁴ However, modern technologies such as Riva Star (SDI Limited Australia) limit the aesthetic impact that characterize regular SDF systems.

Case report

A 3 years and 4 month old female patient attended a private care dental office in Morelia, Mexico due to the presence of spontaneous, acute pain, with a 3-day evolution in the upper right first primary molar that had been controlled with the use of analgesics by the parent. The patient's mother reported that there had been limitations in the child's feeding, so despite the Mexican health recommendations to remain in confinement due to the COVID-19 pandemic, she decided to request urgent care. During the clinical examination, the presence of multiple carious lesions of different degrees was evident, as well as the presence of abscesses and destruction of the crowns of the upper incisors (Figure 1). The clinical and radiographic findings confirmed the diagnosis of severe early childhood caries, with the urgency relating to an irreversible pulpitis diagnosis of the upper right first primary molar (Figure 2).

At the time of presentation, the Mexican Secretariat of Health through the Subsecretariat for the Prevention and Promotion of Health recommended dental care to cover treatments of an urgent nature, but to avoid aerosol-generating procedures during treatment as much as possible. Therefore, after applying local anaesthesia and ensuring absolute isolation of the operative field, a slow-speed handpiece (without irrigation) was used to access the pulp chamber and perform the pulpectomy of the affected molar. At the end of the procedure, the cavity was sealed with Riva Light Cure resin-modified glass-ionomer cement (SDI Limited, Australia) (Figure 3).

The child's mother was informed that it would be advisable to care for as many as possible of the carious lesions in a timely manner. Although other minimally invasive and non-aerosol generating options, such as the Hall technique and atraumatic restorative techniques, could have been used, they may have required additional appointments. Due to the global uncertainty about the pandemic at the time, it was instead decided to apply 38% SDF (Riva Star). As long as its use is accompanied by adequate oral hygiene and dietary habits, this option offered the patient immediate control over the disease process. The objective of the therapy was to avoid the generation of aerosols that are normally necessary when carrying out conventional restorative treatment with composites or crowns, as well as to avoid the need for additional urgent care during the global pandemic.

After a detailed explanation of the side effects from SDF (pigmentation) and a signed informed consent from the parent, carious lesion inactivation was carried out with SDF before resolving the pulpal emergency. The decision to use SDF prior to the pulp therapy was to avoid a change in the patient's behaviour that local anaesthesia could potentially trigger, and therefore complicate the SDF application. It was thoroughly explained to the guardian that the protocol chosen for this procedure did not include immediate restoration. It was agreed that, depending on the evolution of the pandemic situation and once greater aerosol use in the dental office was possible, an aesthetic restorative option could be sought.

After placing cotton roll isolation, the inactivation of carious lesions was carried out, starting with the Riva Star system Step 1 (application of 38% SDF) for 60 seconds in the upper and lower posterior teeth and the left upper and lower canine with subsequent washing with water (Figure 4).

Considering the advantages reported in the literature regarding minimizing pigmentation in the demineralized tissue with the application of potassium iodide with the Riva Star system, it was decided to carry out the complete system protocol on the lower anterior teeth and the right upper canine by applying the Step 1 (38% SDF) for 60 seconds and immediately, without washing, Step 2 potassium iodide application. The manufacturer's recommended ratio of 2:1 potassium iodide to SDF 38% was applied to remove as much of the whitish creamy paste (the chemical reaction that both compounds produce), until finishing with a transparent coat and ending the treatment with a final wash (Figures 5 and 6).

A subsequent appointment was scheduled to carry out the extractions of the upper anterior teeth and provide a solution to the remaining infectious processes (Figure 7). Subsequent 1-, 3- and 6-month follow-ups were carried out based on caries risk (high for this patient). Tactile and visual characteristics of caries activity were carried out based ICDAS-II classifications, verifying inactivity in enamel by observing it to be shiny and smooth to the tactile test and observing dentine with a darker appearance free of biofilm¹⁵.