Effect of application time of 38% silver diamine fluoride solution on arresting early childhood caries in preschool children: a randomised double-blinded controlled trial protocol

Abstract

Background To study the caries lesion activity response to topical 38% silver diamine fluoride (SDF) therapy with increasing treatment application time. Methods/design The design is a stratified-randomised, double-blind, active-controlled, parallel-group clinical trial with nine treatment arms. The trial will involve recruiting at least 414 3- to 5-year-old kindergarten children with caries, who will receive approximately 0.004 mL of 38% SDF (the typical amount applied per the manufacturer’s instructions) to treat each caries lesion. The children will be stratified by caries status, randomised by blocks, and allocated to nine groups of SDF application times: 3, 5, 10, 15, 30, 45, 60, 120, and 180 s. The outcome measure is caries lesion activity (active/arrest) at the tooth-surface level at 6 months post-initial treatment. A calibrated dentist will conduct the blinded clinical examinations at baseline and at the 6-month follow-up. In addition, the parents will be surveyed to examine the effects of the moderating variables, such as oral hygiene, on caries lesion activity. The hypothesis is that a monotonically increasing trend can be found between the SDF application time and the proportion of caries lesions that are arrested. The Cochran-Armitage test for trends in proportions, corrected for clustering within children, will be used to determine the relationship between the exposure to SDF (the SDF application time) and the response (proportion of lesions arrested) in children, taking into consideration the effect of the moderating variables as well as the nesting of multiple caries lesions within an individual child. An EC 80 analysis (an 80% maximal concentration) will be used to determine the exposure (the SDF application time) for 80% caries lesion arrest. Bootstrap methods will be used for clustered data and will be resampled by clustering to determine the 95% confidence interval. Discussion This study will help with determining the optimal application time for SDF treatment. It will provide an evidence-based protocol for the use of SDF to arrest tooth decay in the primary teeth of young children. The results will inform an evidence-based SDF protocol to arrest caries, which affects 573 million children with tooth decay worldwide. Trial registration ClinicalTrials.gov NCT04655430. Registered on 7th December 2020.

A Review of the Protocol of SDF Therapy for Arresting Caries

“…A lack of cooperation often compromises treatment or renders SDF treatment impossible or ineffective. 9 The 60-second application is too long to be applied with young children, older adults, and people with special needs. In these situations, the arrest statuses of the lesions should be reevaluated during recall visits, and the possibility of reapplication should be considered.…”

“…The optimal SDF application time remains unknown and requires further validation. 9 A trial protocol for studying the carious lesion activity response to topical SDF therapy with increasing treatment application times was recently published. 9 The work investigated the rate of caries arrest on children's carious teeth with an application time of 3 seconds to 180 seconds.…”

“…It can also be used to treat young children who are too young to receive conventional restorative treatment in a dental chair. 9 It can furthermore be used to treat older adults who have limited access to dental clinics, as well as people with special needs who are unable to cooperate with dental treatment.…”

“…The United States Food and Drug Administration has cleared SDF as a Class II medical device for professional use to manage dentine hypersensitivity. 9 In 2017, Health Canada approved SDF for dental care. Several manufacturers developed an SDF solution with a concentration at 3.8% to 38% for dental use.…”

“…However, based on their clinical experience, dentists often use SDF to arrest caries with different SDF application times. 9 This study's objective is to review the SDF application time that provides the best practice of SDF therapy for arresting caries.…”