Silver diamine fluoride solution for prevention of occlusal surface caries in primary molars

Abstract

This thesis consists of two systematic reviews and two original studies related to caries prevention and management in preschool children. The first systematic review aimed to describe and evaluate the caries patterns among the 21st century preschool children globally and found that cavitated caries lesions were common in the primary maxillary incisors and the molars in both dental arches. Occlusal surfaces of the mandibular molars were the most frequently affected surfaces. The second systematic review was combined with a network meta-analysis. The review aimed to summarize and rank the effectiveness of clinical interventions using different agents for primary prevention of early childhood caries (ECC). The included trials that used a single or combination of many different agents. Results show that compared to the control, fluoride foam, fluoride salt, probiotic milk plus low fluoride toothpaste, fluoride varnish, and fluoride varnish plus high fluoride toothpaste are effective in reducing caries increment or incidence in preschool children. However, the certainty of evidence is low.

The first original study was an online questionnaire survey to describe the extent to which SDF had been introduced into the education of undergraduate students in the dental schools in Southeast Asia (SEA). The questions were about the duration, method, contents, and barriers regarding the teaching of silver diamine fluoride (SDF). A total of 81 responses from 49 schools were received, giving a school-level response rate of 54%. SDF was taught in the undergraduate program in 86% of the respondent schools. The use of SDF for arresting cavitated caries lesions was the most commonly covered. Regarding preventing new caries development, only 66-79% of the responses were positive. The teaching contents were inconsistent regarding the use of SDF for primary prevention of caries. The last section is a clinical study conducted to investigate the effectiveness of SDF in preventing caries on the occlusal surface in the primary molars. This was a parallel 3-arm, double-blind, randomized controlled trial. A total of 791 children were recruited and randomly allocated to one of the three study groups - Group 1: 38% SDF, Group 2: 5% NaF varnish, and Group 3: tonic water (placebo). After 30 months, the child-level caries incidence rates were 25.5%, 24.4% and 30.1% in Groups 1, 2 and 3, respectively (p=0.295). At the tooth-level, the caries incidence rates were 7.5%, 7.6% and 9.1%, respectively (p=0.527). In the final multi-variable model, gender, oral hygiene status, baseline caries experience and surface status, tooth type and location, snack-taking frequency and family income significantly influenced the 30-month caries incidence. Similar results were detected in the generalized estimating equation models and the Cox regression model that the development of cavitated caries in the study primary molars in the SDF group was significantly lower than that of the placebo group. It is concluded that semi-annual application of 38% SDF is effective in preventing cavitated caries in occlusal surfaces of primary molars, and the effectiveness of SDF and NaF varnish is not significantly different.