Biphasic Functions of Sodium Fluoride (NaF) in Soft and in Hard Periodontal Tissues

Sodium fluoride (NaF) is widely used in clinical dentistry. However, the administration of high or low concentrations of NaF has various functions in different tissues. Understanding the mechanisms of the different effects of NaF will help to optimize its use in clinical applications. Studies of NaF and epithelial cells, osteoblasts, osteoclasts, and periodontal cells have suggested the significant roles of fluoride treatment. In this review, we summarize recent studies on the biphasic functions of NaF that are related to both soft and hard periodontal tissues, multiple diseases, and clinical dentistry.

Efficacy of Probiotic, Chlorhexidine, and Sodium Fluoride Mouthrinses on Mutans Streptococci in 8- to 12-Year-Old Children: A Crossover Randomized Trial

<b><i>Introduction:</i></b> The oral cavity is home to a diverse and distinct microbiome. While the role of oral bacteria in cariogenic and other dental diseases is irrefutable, their beneficial effects in the form of probiotics (PB) has been less studied, especially pertaining to oral diseases in children. This study compares the efficacy of a PB mouthrinse with 0.12% chlorhexidine (CHX) and 0.05% sodium fluoride (NaF) mouthrinse on the colony counts of mutans streptococci (MS) in children. <b><i>Methods:</i></b> A triple-blind crossover randomized trial between interventional groups was planned. Fifty-one children between 8 to 12 years of age were divided into three groups (I, II, and III) and were exposed to all three mouthrinses (A, B, and C) by randomized allocation for a period of two weeks with an inter-phase washout period of four weeks. Pre- and post-interventional MS counts (CFU/mL) were assessed, and the mean change was analysed using the <i>t</i> test (intragroup) and ANOVA (intergroup and crossover). <b><i>Results:</i></b> The mean changes in the colony counts obtained with the use of PB, CHX, and NaF mouthrinses were −1.0223 (−1.2201 to −0.8246), −0.9564 (−1.1503 to −0.7626), and −0.9511 (−1.1554 to −0.7467), respectively, which were statistically significant (<i>p</i> &#x3c; 0.0001). However, the intergroup comparison for the mean change in colony counts revealed no statistically significant differences (<i>p</i> &#x3e; 0.05). <b><i>Conclusion:</i></b> The study concluded that the PB mouthrinse was equally efficacious as compared to CHX and NaF mouthrinses against MS in 8- to 12-year-old children. However, further studies are recommended to strengthen the evidence.

Effects of Homemade Nano-Hydroxyapatite and Olive Oil Paste on Remineralization of Early Caries Lesions

Nano-hydroxyapatite (nHAP) particles are a new generation of materials reported to remineralize enamel lesions. The purpose we aimed was to compare the in vitro effects of fluoride gel, sodium fluoride toothpaste, and homemade nHAP paste on remineralizing artificial early enamel caries. Methods: Incipient caries were induced in 21 extracted, sound premolar teeth by storing each specimen in a demineralization solution for 72 hours, followed by pH cycling. The samples (n= 7, each) were then treated with 2% neutral fluoride gel, 0.25% sodium fluoride toothpaste, or homemade nHAP paste, comprising a mixture of nHAP powder and olive oil. After demineralization and remineralization, the results were compared using the DIAGNOdent pen (KaVo, Germany). The data were statistically analyzed using paired t-tests and a one-way ANOVA test. Outcomes: The degree of demineralization in each of the three groups (fluoride gel group, 15.71; sodium fluoride dentifrice group, 15.28; nHAP paste group, 16.71) was significantly elevated compared to baseline (3, 2.5, 2.28, respectively); however, no significant difference was observed between the remineralization readings in each of the three groups (6, 7, 5.5, respectively) (p > 0.05). In conclusion, we concluded that the homemade nHAP paste had a beneficial effect on the remineralization of initial enamel caries lesions.

Luteolin Reduces Blood Pressure via Down-regulation of Renal Angiotensin II Receptor and Mineralocorticoid Receptor Expressions in Rats Co-exposed to Diclofenac and Sodium Fluoride

This study was designed to investigate the modulatory role of Luteolin (Lut) on haemodynamic parameters and the potential mechanisms involving renal Angiotensin II (AT2R) and Mineralocorticoid (MCR) receptors in renal toxicity induced by co-exposure to Diclofenac (Dcf) and sodium fluoride (NaF) in rats. Male Wistar rats were administered with either vehicle (control), Dcf only (9 mg/kg orally) or concurrently with NaF (300 ppm in drinking water). Other groups were treated with LutA (100 mg/kg) or LutB (200 mg/kg) along with Dcf and NaF exposures. All treatments lasted 8 days, following which blood pressure indices were measured using tail-cuff plethysmography. Renal expressions of AT2R and MCR were studied with immunohistochemistry, while biomarkers of oxidative and antioxidant status were also measured in the kidneys. Systolic, diastolic and mean arterial pressures were significantly (p<0.05) reduced in Dcf-treated rats, compared to control values. However, co-treatment with NaF or Lut restored these parameters. While the expression of AT2R and MCR was high in the Dcf and Dcf+NaF groups, treatment with Lut caused obvious reduction in the renal expression of these receptors. Increased lipid peroxidation (Malondialdehyde) and protein oxidation (protein carbonyls) with a lowering of reduced glutathione levels contributed to the renal toxicity of Dcf, which was significantly ameliorated in Lut-treated rats. The protective effect of Lut on blood pressure was probably mediated by stimulation of renal expressions of AT2R and MCR, reduction of oxidative stress and an improvement of renal antioxidant status.