However, a recent meta-analysis found that among primary teeth in young children, “the caries-preventive effect from the low-fluoride formulas (<1,000ppm) was statistically non-significant.” There was high quality evidence that “tooth brushing with fluoride toothpaste was more effective when carried out twice a day than irregular, and when supervised by a custodian during childhood.”¹²

The meta-analysis also found that fluoride varnishes may offer a PF of 43 per cent with two to four professional applications a year, with most benefit among the vulnerable. Low-quality evidence suggests a PF of 29 per cent for fluoride mouth rinses, and while fluoride tablets, drops, lozenges, gums have a combined PF of 24 per cent, there is “very low” quality evidence to support this.¹²

Among other self-care non-fluoride approaches, the quality of evidence varies: while xylitol chewing gums may offer a PF of 59 per cent, their evidence base is considered low; while a high-evidence base for the antibacterial triclosan in a copolymer toothpaste suggests a PF of 5 per cent. Interdental cleaning (brushing and flossing) may have a PF of 24 per cent, but this is based on very low-grade evidence.¹²

Among professional care, there was moderate evidence supporting a PF of 84 per cent for fissure sealants using resin-based materials, but the process requires regular check-ups and repair.¹² Researchers have been looking at nano-technology, such as nano-hydroxyapatite in combination with fluoride as a varnish. While such an approach in vitro was found to significantly remineralise tooth enamel damaged by acid erosion, full restoration was not possible.¹⁷