A Multi-methods Approach to Build Evidence-Based Practice for Using Silver Diamine Fluoride for Managing Carious Lesions in Children

  • Nassar Seifo

Student thesis: Doctoral ThesisDoctor of Philosophy

Abstract

Introduction: In recent years, as a result of a better understanding of the pathology of dental caries, there has been a shift from traditional ‘drill-and-fill’ techniques towards more minimal-intervention, evidence-supported treatment options. Silver diamine fluoride (SDF) was first explored as a treatment option for managing carious lesions in Japan in 1969. SDF is a clear, odourless liquid containing silver and fluoride, which act synergistically to arrest carious lesions through a variety of mechanisms. It was cleared by the Food and Drug Administration in the United States in 2014 for managing dentine hypersensitivity. Since then, there has been growing global interest in its “off-label” use for managing carious lesions.

SDF became available for use in the United Kingdom in 2016, however, its use remains limited here. One reason for this may be that evidence alone does not provide clinicians with enough information to inform decisions, especially in relation to the adoption of new treatments or technologies. Ensuring that healthcare is not only underpinned by the best available evidence, but also includes the values and preferences of individual patients and clinicians, is the basis of Evidence-Based Practice. Although the three components make up EBP, research often focus on the best research evidence only and misses the latter two components.

Aim: To explore the use of SDF for managing carious lesions in children within the framework of the three components of Evidence-Based Practice; Best Research Evidence, Clinical Expertise and Patients’ Values and Preferences.

Methods: This study comprised three arms, which directly align with the three components of Evidence-Based Practice:

(1)An umbrella review to explore the evidence for SDF’s effectiveness for managing carious lesions. Five electronic databases were searched for Systematic Reviews investigating SDF for carious lesions prevention or arrest (1970-2018) without language restrictions. Systematic reviews were selected, data extracted, and risk of bias assessed using (Risk Of Bias In Systematic reviews) ROBIS tool, by two independent reviewers, in duplicate. Corrected covered area was calculated to quantify studies' overlap across systematic reviews.

(2)An exploration of Dental Professionals’ views and acceptability of SDF. Semi-structured interviews with 14 dental professionals from National Health Service (NHS) Tayside and NHS Grampian were conducted. Interviews investigated dental professionals’ existing knowledge and experience of SDF, if applicable, in addition to their perceived advantages, disadvantages, barriers and enablers to its use.

(3)An exploration of parents’ and children’s views and acceptability of SDF. A multi-method study with parents and children aged (4-12) years old was undertaken. The study comprised semi-structured interviews and a questionnaire-based survey to investigate parents’ and children’s acceptability of SDF treatment, including the barriers and enablers to its use, as well as their preferences.

Results:

Best Research Evidence

Eleven systematic reviews were included in the umbrella review; four focussing on SDF for root caries in adults and seven on coronal caries in children. These cited 30 studies (four root caries; 26 coronal caries) appearing 63 times. Five systematic reviews were judged to be "low", one "unclear" and five "high" risk of bias. Overlap of studies included across the systematic reviews was very high. SDF had a positive effect on prevention and arrest of coronal and root caries, consistently outperforming comparators. For root caries prevention, the prevented fraction was 25-71% higher for SDF compared to placebo (two systematic reviews with three studies) and prevented fraction 100-725% for root caries arrest (one systematic with two studies). For coronal caries prevention, prevented fraction = 70-78% (two systematic reviews with two studies) and prevented fraction = 55-96% for coronal caries arrest (one systematic review with two studies) with arrest rates of 65-91% (four systematic reviews with six studies). Eight systematic reviews reported adverse events, seven of which reported arrested lesions black staining.

Clinical Expertise

Thirteen of the 14 Dental Professionals interviewed were familiar with, or had some existing knowledge of, SDF. Four had used it to treat patients. Most Dental Professionals thought that the main advantage of SDF was that it required minimal patient cooperation. SDF was perceived as a simple, pain-free and non-invasive treatment approach that could help children acclimatise to the dental environment. However, the black staining of arrested carious lesions was reported as the main disadvantage and the greatest barrier to its use in practice. Dental Professional participants believed that this discolouration may concern some parents fearing that the black appearance may instigate bullying at school or that others may judge parents as neglecting their child’s oral health. They also thought that education of clinicians about SDF use and information sheets for parents would enhance the uptake of SDF in dental practice. Dental Professional participants believed that younger children might not be as bothered by the discolouration as older ones and anticipated greater acceptance of SDF for back primary teeth by both parents and children.

Patients’ values and preferences

Parents’ views did not differ from those of the Dental Professionals. Parent participants believed that SDF would be particularly useful for anxious or uncooperative children and the simplicity of the application procedure could make SDF an entry point to more complex procedures. They however expressed similar concerns to those of Dental Professionals that SDF-induced black staining could trigger bullying at schools or nurseries, if applied on front teeth, and suggested that this could subject them to judgment by others and accusations of being neglecting of their child’s oral health. The children who were interviewed also expressed concerns about being picked on by their peers if they had discoloured front teeth. As a result, parents and children were more accepting of the SDF on non-visible back teeth. Parents’ acceptance of SDF also increased if their child was less cooperative with the dentist or if SDF treatment avoided extractions under a general anaesthetic. In agreement with Dental Professionals’ preconceived ideas, younger children appeared less concerned about the discolouration and the gender of the child did not seem to influence parents’ decision-making nor the child’s preferences regarding using SDF.

Conclusions: Despite the consistent supportive evidence reported in the systematic reviews included in the umbrella review for the use of SDF for arresting carious lesions in the primary dentition and Dental Professionals’ awareness of it, uptake is still limited. Nevertheless, the potential advantages offered by SDF were acknowledged by both Dental Professionals and parents’ who believed that SDF could be particularly advantageous for less cooperative and anxious children. Dental Professionals and parents agreed that SDF-induced black staining could be the main potential barrier to its use, with a concern raised that this could instigate bullying at schools or nurseries, especially for more self-conscious older children who showed a higher reluctance for receiving SDF on front teeth in their interviews. Dental Professionals suggested actions, such as developing SDF information leaflets or running courses to familiarize Dental Professionals with SDF that could help overcome some barriers they highlighted. 

In conclusion, having explored the evidence available around using SDF, Dental Professionals’ clinical expertise with SDF and patients’ preferences regarding the child’s dental treatment, SDF could be a valuable treatment regimen to manage dental caries in children.
Date of Award2021
Original languageEnglish
SupervisorNicola Innes (Supervisor), John Radford (Supervisor) & Heather Cassie (Supervisor)

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