Caries management, Post-COVID
Will new protocols that have been developed and refined be incorporated, long-term, into paediatric care?
When COVID-19 emerged, dentistry was flagged as a “high-risk” healthcare profession, observed Dr John Walsh in a presentation to the RCSI Faculty of Dentistry Charter Day last month. “However,” he added, “probably because of the existing excellent infection control procedures that dentists routinely use, in addition to them rapidly incorporating the new enhanced protocols, to date there have been no reported cases of COVID-19 transmission from dentist to patient or vice versa.”
In fact, said Dr Walsh, the most recent survey by the American Dental Association showed that less than one per cent of dentists in the United States had tested positive and none from patient transmission1, possibly indicating that dentists carry infection control knowledge into their private lives as well.
Dr Walsh is a specialist in paediatric dentistry and orthodontics, a past Dean of the Faculty of Dentistry, RCSI, and is Director of the specialty programme in paediatric dentistry at Hamad Medical Corporation (HMC), Qatar, developed by RCSI in collaboration with HMC.
In his presentation, Dr Walsh explored the peculiarities of COVID-19 infection and children; initial research suggests that COVID-19 disease in children is less severe than in adults, with only five per cent developing dyspnea and only 0.6 per cent developing more acute respiratory distress syndrome or, more rarely, multisystem inflammatory syndrome, for example Kawasaki disease2.
It was felt, he said, that dentists were at less risk of transmission of COVID from children than adults. “However,” he added, “some early trends have been detected that the new virus strains in children may have increased transmissibility. So, all of the precautions still have to be maintained and we have to be conscious that children can be transmitters.”
We have to be vigilant that the attractive simplicity does not become an excuse for compromise in the standards of treatment that children deserve
The strong, initial advice when COVID was first revealed as a threat, said Dr Walsh, was that when treating children all aerosol generating procedures should be avoided. In effect, this meant that many of the routine procedures previously carried out, for example rubber cup prophylaxis, scaling, restorative procedures involving high speed handpieces, three-in-one syringes, amongst many others, were no longer advised. As a result, said Dr Walsh, the choice was to either cease treatment until the virus was eliminated, or to find an alternative way to treat children that decreased aerosol generating procedures.
Dr Walsh noted that early childhood caries (ECC) is defined as the presence of one or more decayed, missing or filled teeth in any child under the age of six. It represents one of the most common chronic infectious diseases in the world with very high social costs. Children present with masticatory or spontaneous pain and difficulty in chewing and speaking, as well as the psychological effects such as a reduction in personal and self-esteem (Figure 1).
Pre-COVID, the treatment of the ECC involved the instigation of a strong individual preventive programme, allied to a comprehensive restorative phase. “The aims were simply to treat the decay present and to prevent its recurrence,” said Dr Walsh. “Of course, procedures such as gross caries removal, pulpotomy, and stainless-steel crowns all involved aerosol generating procedures. So initially, treatment was postponed under the revised COVID guidelines.
“Over the previous 10 years, some new treatments had evolved for the management of ECC in developing countries, where the cost of comprehensive care was an obstacle to treatment. The realisation dawned that these treatments still might have a role to play in the resumption of treating children within the COVID restraints.
“The newer treatments that have evolved that can be used in the treatment of early childhood caries are known as minimally invasive treatments. Their attraction lies in the fact that to a large extent, they are non-aerosol generating procedures, and local anesthesia is not required.”
There are two broad categories of treatment, noted Dr Walsh: non-invasive and micro- invasive treatments. The non-invasive treatments are those that fall into the preventive spectrum, including the use of Duraphat, known as fluoride varnish3, containing 22,600 parts per million. It’s applied with a micro brush to any areas of the teeth that may be thought to be susceptible to decay.
The second substance that can be used is silver diamine fluoride; a clear or tinted liquid that combines the antibacterial effects of silver and the remineralising effects of fluoride. Multiple in vitro studies document its effectiveness in reducing specific cariogenic bacteria and its remineralising potential on enamel and dentine4. Silver diamine fluoride is applied to cavitated lesions with a micro brush but, noted Dr Walsh, “great care has to be taken not to make contact with any soft tissue as it causes a temporary tattoo-like stain on the soft tissue. Of course, the fact that the arrested lesions turn black has to be carefully explained to the child’s parents and consent obtained.”
Dr Walsh explained that on application, a reaction takes place; calcium fluoride and fluorohydroxyapatite are produced – both having a remineralising effect – and the silver ions that are also present have an antimicrobial effect by inhibiting the mobility of the bacteria, rupturing the cell membrane and altering the DNA within the bacteria, resulting in its death.
Another material that can be used is casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); a bioactive agent derived from milk protein casein and commonly known as ‘tooth mousse’5. “It has a remarkable ability to stabilise calcium phosphate in solution and to substantially increase the level of calcium phosphate in dental plaque,” said Dr Walsh. “It buffers the free calcium and phosphate ion activities, thereby helping to maintain a state of super-saturation with respect to tooth enamel, reducing demineralisation and promoting remineralisation.”
Micro-invasive treatments consist of interim therapeutic restoration (IRT), atraumatic restorative treatment (ART), and silver diamine modified atraumatic restorative treatment (SMART). “They are essentially three different variations of the same procedure with an increasing level of intervention,” said Dr Walsh.
“For IRT, no attempt is made to remove decay, but high-viscosity glass ionomer cement (GIC) is placed on the isolated teeth in an effort to use the fluoride releasing, stabilising properties of the glass ionomer material. In simple terms, it ‘buys the dentist time’.
“ART goes a little further; decay is carefully removed with a spoon excavator and then high viscosity glass ionomer cement is placed over the carious lesions. To achieve restoration of both aesthetics and caries control, the caries is excavated and then the GIC is placed using a paediatric crown form. The SMART technique uses the ART, [but] precedes it with the use of silver diamine application – so you get the immediate cariostatic effect, which is then supplemented by the GIC restoration of form and contour. Hall crowns are the final restorative procedure that can be used to maintain a primary tooth in-situ. The stated advantage is the absence of any need for tooth preparation, although frequently separators have to be placed and they can be quite painful for a child. In addition, the inevitable over-extension of the crown can sometimes result in potential problems, as evidenced by gingival blanching (Figure 2). The other problem that you encounter with them frequently is that because of the overextension, the poor adaptation can result in leakage and recurrent decay (Figure 3).”
Walsh concluded: “So, we now have additional treatments in our repertoire that can significantly help in the treatment of children during the COVID era. But the question is, which of these will still be used post-COVID. While the evidence suggests that many of them are successful, albeit in short term studies, we nevertheless have to be vigilant that the attractive simplicity of the techniques does not become an excuse for compromise in the standards of treatment that children deserve.
“My opinion is that when you look at the excellent protocol that is currently outlined by Stefano Ciannetti6 and then consider which of these techniques will be continued to be used post-COVID, I would predict that we will continue to use the preventive techniques that he clearly outlines. But the micro-abrasive techniques that are proposed at the present time will be rationalised to the use of SMART techniques going forward. Conventional stainless-steel crowns with appropriate local anesthesia will continue to be the gold standard. Silver diamine will completely take over the realm of prevention.”
1. Estimating COVID-19 prevalence and infection control practices among US dentists doi: https://doi.org/10.1016/j.adaj.2020.09.005
2. Clinical characteristics of children and young people admitted to hospital with covid-19 in United Kingdom: prospective multicentre observational cohort study BMJ 2020; 370 doi: https://doi.org/10.1136/bmj.m3249
3. Fluoride varnishes for preventing dental caries in children and adolescents. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD002279. DOI: https://doi.org/10.1002/14651858.CD002279.pub2
4. Antibacterial effects of silver diamine fluoride on multi-species cariogenic biofilm on caries. Annals of clinical microbiology and antimicrobials, 12, 4. https://doi.org/10.1186/1476-0711-12-4
5. Evaluation of the efficacy of casein phosphopeptide-amorphous calcium phosphate on remineralization of white spot lesions in vitro and clinical research: a systematic review and meta-analysis. BMC Oral Health 19, 295 (2019). https://doi.org/10.1186/s12903-019-0977-0
6. Model for Taking Care of Patients with Early Childhood Caries during the SARS-Cov-2 Pandemic. Int. J. Environ. Res. Public Health 2020, 17(11), 3751; https://doi.org/10.3390/ijerph17113751