Simultaneous assessment of acidogenesis-mitigation and specific bacterial growth-inhibition by dentifrices

Dentifrices can augment oral hygiene by inactivating bacteria and at sub-lethal concentrations may affect bacterial metabolism, potentially inhibiting acidogenesis, the main cause of caries. Reported herein is the development of a rapid method to simultaneously measure group-specific bactericidal and acidogenesis-mitigation effects of dentifrices on oral bacteria. Saliva was incubated aerobically and anaerobically in Tryptone Soya Broth, Wilkins-Chalgren Broth with mucin, or artificial saliva and was exposed to dentifrices containing triclosan/copolymer (TD); sodium fluoride (FD); stannous fluoride and zinc lactate (SFD1); or stannous fluoride, zinc lactate and stannous chloride (SFD2). Minimum inhibitory concentrations (MIC) were determined turbidometrically whilst group-specific minimum bactericidal concentrations (MBC) were assessed using growth media and conditions selective for total aerobes, total anaerobes, streptococci and Gram-negative anaerobes. Minimum acid neutralization concentration (MNC) was defined as the lowest concentration of dentifrice at which acidification was inhibited. Differences between MIC and MNC were calculated and normalized with respect to MIC to derive the combined inhibitory and neutralizing capacity (CINC), a cumulative measure of acidogenesis-mitigation and growth inhibition. The overall rank order for growth inhibition potency (MIC) under aerobic and anaerobic conditions was: TD> SFD2> SFD1> FD. Acidogenesis-mitigation (MNC) was ordered; TD> FD> SFD2> SFD1. CINC was ordered TD> FD> SFD2> SFD1 aerobically and TD> FD> SFD1> SFD2 anaerobically. With respect to group-specific bactericidal activity, TD generally exhibited the greatest potency, particularly against total aerobes, total anaerobes and streptococci. This approach enables the rapid simultaneous evaluation of acidity mitigation, growth inhibition and specific antimicrobial activity by dentifrices

The efficacy of baking soda dentifrice in controlling plaque and gingivitis: A systematic review

Objective: To test the efficacy of a dentifrice containing baking soda (BS), compared with dentifrice without BS for controlling plaque and gingivitis.Materials and methods: MEDLINE‐PubMed and Cochrane‐CENTRAL were searched. The inclusion criteria were randomized controlled clinical trials including healthy participants aged 18 years or older. Studies were selected that compared the effect of toothbrushing with a dentifrice with and without BS on the clinical parameters of plaque and gingivitis. Data were extracted from the selected studies, and a meta‐analysis was performed.Results: The search retrieved 21 eligible publications. Among these papers, 43 comparisons were provided, with 23 involving a single‐use design and 20 being evaluations with a follow‐up. Negative controls were found, or positive controls for which various active ingredients had been used. The included studies showed a moderate overall potential risk of bias and considerable heterogeneity. The meta‐analysis of plaque scores from the single‐brushing experiments showed that BS dentifrice (BS‐DF) was associated with significantly better outcomes than the negative control dentifrices (DiffM −0.20; P < 0.0001; 95% CI: [−0.27; −0.12]) or the positive control dentifrices (DiffM −0.18; P < 0.0001; 95% CI: [−0.24; −0.12]). This finding was only confirmed in studies that used a follow‐up design as compared to a negative control (DiffM −0.19; P = 0.01; 95% CI: [−0.34; −0.04]). The indices of gingival bleeding also improved when the comparison was a negative control (DiffM −0.08; P = 0.02; 95% CI: [−0.16; −0.01] and (DiffM −0.13; P < 0.001; 95% CI: [−0.18; −0.08]. However, for the gingival index scores, the meta‐analysis did not reveal any significant differences.Conclusion: BS‐DF showed promising results with respect to plaque removal in single‐use studies. However, the finding was partially substantiated in follow‐up studies. Studies that assessed bleeding scores indicated that a small reduction can be expected from BS, relative to a control product