The dental profession has experienced a dramatic acceleration in the use of communication systems and information-based technologies over recent years, originating new paradigms for the prevention and promotion of oral health. The purpose of this systematic review was to determine the effect of teledentistry-based (telematic) strategies, reported in randomized controlled trials and quasi-randomized trials, with a focus on oral health prevention and promotion–related outcomes in patients of all ages. We searched Medline via PubMed, SCOPUS, and Web of Science from inception until August 2020, regardless of the language of publication. We selected studies for inclusion and conducted data extraction, assessed risk of bias (Cochrane tool), and evaluated the certainty of the evidence (GRADE approach) in duplicate and independently. Out of 898 potentially eligible references, we selected 43 for full-text screening, of which 19 studies proved eligible: 18 randomized controlled trials and 1 quasi-randomized study. Virtual interventions were mostly asynchronous via apps ( n = 9), text messages ( n = 9), or computer-aided learning ( n = 1). The use of teledentistry as compared with conventional strategies may result in a large reduction in the plaque index (standardized mean difference, −1.18; 95% CI, −1.54 to −0.82; I² = 92%; low certainty) and will likely result in a large reduction in the gingival index (standardized mean difference, −2.17; 95% CI, −3.15 to −1.19; I² = 97%; moderate certainty) and in the incidence of white spot lesions (risk ratio, 0.48; 95% CI, 0.35 to 0.66; I² = 0%; moderate certainty), with an increased effect over time. Evidence suggests that teledentistry, particularly mHealth (messages and apps), is a promising clinical tool for preventing and promoting oral health, especially under the accelerated virtualization of dentistry. Future studies should include a broader spectrum of the population, including adults and elders, to better inform policy and implementation of teledentistry (PROSPERO: CRD42020192685).

Remineralization of caries lesions is naturally achieved by salivary ions, and it can be enhanced by external factors or elements such as fluoride. Numerous studies have demonstrated the remineralizing efficacy of fluoride therapies as well as the limitations with some groups of the population. Consequently, developing new remineralization therapies to close this gap in efficacy has been a priority for the last 2 decades. In this review, we summarize and briefly discuss some of the latest advances in remineralization therapies. Most new therapies try to enhance the effect of fluoride by adding other potentially active ingredients to the formulation, such as calcium, phosphate, stannous, xylitol, and arginine. Other remineralization strategies have focused on creating remineralizing scaffolds within the lesions (e.g., self-assembling peptides). While several of the new remineralization strategies have progressed significantly in recent years, for most of them, the evidence is still insufficient to assess their true clinical potential.

Due to gingival recession both enamel and root dentine are at risk of developing caries. Both tissues are exposed to a similar environment, however there is not a validated model to evaluate the effect of fluoride on these dental substrates simultaneously. Hence, this study aimed to validate a caries model to evaluate the effect of fluoride to prevent demineralization on enamel and root-dentine. Streptococcus mutans UA159 biofilms were formed on saliva-coated bovine enamel and root dentine slabs (n = 12 per group) mounted in the same well of culture plates. The biofilms were exposed 8×/day to 10% sucrose and treated 2×/day with fluoridated solutions containing 0, 150, 450, or 1,350 ppm F; thus, simulating the use of low to high fluoride concentration toothpastes. The pH values of the culture medium was monitored 2×/day as a biofilm acidogenicity indicator. After 96 h, biofilms were collected for fluoride concentration analysis. The percentage of surface hardness loss (%SHL) was calculated for slabs. The fluoride uptake by the enamel and dentine was also determined. The model showed a dose-response because the biofilm and fluoride uptake increased and %SHL decreased at increasing fluoride concentrations (p < 0.05). Fluoride in the biofilm formed on dentine and fluoride uptake by dentine were higher than those for enamel. With the same fluoride concentration treatment, the percentage of reduction of demineralization was lower for dentine than for enamel. In conclusion, the model was validated in terms of a dose-response effect of fluoride on enamel and root dentine. Furthermore, the findings support the clinical data, suggesting that higher fluoride concentrations are necessary to control caries of root dentine than of enamel.

A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH^- to reach pH 5.5, respectively). Eight volunteers with a normal salivary flow rate and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

High fluoride dentifrice (FD; 5,000 ppm F) has been recommended to arrest root dentine lesions and to control enamel caries in high-risk patients. Also, standard FD (1,100 ppm F) in combination with professional fluoride application has been recommended to control dentine caries, but the effect of this combination on enamel has been considered modest. Considering the lack of evaluation comparing the use of 5,000 ppm FD (5,000-FD) versus acidulated phosphate fluoride (APF) application combined with 1,100 ppm FD (1,100-FD) on the inhibition and repair of caries lesions in both enamel and dentine, we conducted this in situ, double-blind, crossover study of 3 phases of 14 days. In each phase, 18 volunteers wore palatal appliances containing enamel and root dentine specimens, either sound or carious, to evaluate the effect of the treatments on the inhibition or repair of caries lesions, respectively. The treatments were non-FD (negative control), 5,000-FD, or 1 APF gel application on dental specimens combined with 1,100-FD used twice per day (APF + 1,100-FD). The reduction of demineralization and enhancement of remineralization were assessed by surface and cross-sectional hardness. Fluoride concentration was determined on dental specimens and on the formed biofilm. For enamel, APF + 1,100-FD and 5,000-FD did not differ regarding the inhibition of demineralization and repair of caries lesions. However, for dentine the difference between these treatments was inconclusive because while APF + 1,100-FD was more effective than 5,000-FD in caries lesion reduction and repair, 5,000-FD was more effective than APF + 1,100-FD in the reduction of surface demineralization. Therefore, the findings show that the combination of APF + 1,100-FD is as effective as 5,000-FD in enamel inhibition of demineralization and enhancement of remineralization.

There is no consensus about the clinical recommendation of the time that Duraphat^® varnish should be maintained on enamel surfaces without suffering mechanical disturbance by the patient. Considering the importance of calcium fluoride (CaF₂)-like reservoirs on the anticaries effect of professional fluoride application, an in vitro study was designed to test the reactivity of Duraphat^® varnish with enamel forming these reservoirs as a function of time. Since most fluoride in Duraphat^® varnish is insoluble to react and form products on enamel, the relative contribution of the varnish soluble and insoluble fluoride fractions to the reactivity was also evaluated. For this, whole-varnish, containing soluble and insoluble fluoride (total fluoride concentration of 23699±384 µg F/g), or centrifuged varnish, containing only soluble fluoride (fluoride concentration of 258±97 µg F/g), were applied in a standardized manner on enamel slabs (n=8/varnish group/time), which were immersed in continuously renewed artificial saliva for up to 36 h. CaF₂-like reservoirs formed on enamel by varnish application were extracted using 1 M KOH and fluoride concentration was measured with ion specific electrode. The results were expressed as µg F/cm² of enamel area. Whole varnish formed significantly higher fluoride concentration on enamel than centrifuged varnish, reaching maximum concentration at 24 h (22.0±4.5 µg F/cm²). Centrifuged varnish reached maximum concentration at 6 h (3.20±0.81 µg F/cm²). In conclusion, a longer varnish retention time than the usually recommended could improve the anticaries effect of Duraphat^® varnish, allowing that NaF particles, initially insoluble in the varnish matrix, prolong the reactivity with enamel.