Introduction: We aimed to compare the antimicrobial efficacy of chlorhexidine (CHX) and sodium hypochlorite (NaOCl), 2 irrigants routinely used in root canal therapy of permanent teeth. Methods: Electronic databases, including PubMed, EMBASE, Web of Science, and Cochrane Library, were searched for randomized controlled trials published until March 2020. The meta-analysis of relative risk (RR) and standardized mean difference (SMD) was performed using a random effects model with a 95% confidence interval (CI). Subgroup analysis was performed for culture and molecular methods of bacterial detection. Results: The literature search yielded 2110 records without duplicates. Eight studies were eligible for a systematic review. No significant differences in the incidence of samples with positive bacterial growth after irrigation (RR 5 1.003; 95% CI, 0.729-1.380; P 5 .987) and mean bacterial number changes (SMD 5 0.311; 95% CI, 20.368 to 0.991; P 5 .369) were observed between CHX and NaOCl in the culture and molecular subgroups. Heterogeneity in RR (I 2 5 0.000%, P 5 .673) was low among studies, whereas considerable heterogeneity was observed in the analysis of SMD (I 2 5 76.336%, P 5 .005). Conclusions: Our findings suggest that both CHX and NaOCl irrigation can reduce bacterial infections without any significant difference in antimicrobial efficacy between them, despite their difference in molecular mechanisms. Therefore, each can be used as the main antibacterial root canal irrigant. However, our results were limited by inconsistencies among retrieved articles and a lack of clinically relevant outcomes. Further well-designed clinical studies are warranted to supplement our results.

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Introduction: At the initial part of the gastrointestinal tract, multiple tissues serve the normal function of food delivery. Periodontal structures are integral elements of these. When they deteriorate, it is extremely challenging to regenerate and reconstruct them. The conventional intervention for periodontal disease is scaling and root planning with the aim of reducing pathogenic bacteria. However, periodontal pathogens can rapidly recolonize treated areas. Probiotics have been proposed as novel tools for managing oral health by suppressing pathogenic bacteria through their anti-inflammatory effect, but the available data are controversial.Aim: Therefore, we performed a meta-analysis to study the effect of probiotics on periodontal pathogenic bacteria.Methods: The study was registered in PROSPERO under registration number CRD42018094903. A comprehensive literature search from four electronic databases (PubMed, Cochrane CENTRAL, Embase, and Web of Science) yielded nine eligible records for statistical analysis. Studies measuring bacterial counts in saliva and supra- and subgingival plaque were included. Bacterial counts were analyzed using standard mean difference (SMD) and by a random effects model with the DerSimonian–Laird estimation.Results: The results showed a significant decrease in the overall count of Aggregatibacter actinomycetemcomitans in the probiotic-treated group compared to the control at 4 weeks (SMD: −0.28; 95% CI: −0.56–−0.01; p = 0.045) but not later. Analyzing the bacterial counts in subgroups, namely, in saliva and supra- and subgingival plaque, separately, yielded no significant difference. Probiotics had no significant effect on the overall count of Porphyromonas gingivalis at 4 weeks (SMD: −0.02; 95% CI: −0.35−0.31; p = 0.914) or later. Subgroup analysis also revealed no significant difference between treatment and control groups nor did probiotics significantly decrease the overall and subgroup bacterial counts of Prevotella intermedia, Tannerella forsythia, and Fusobacterium nucleatum.Conclusion: Our data support the beneficial effect of probiotics in reducing A. actinomycetemcomitans counts, but not of other key periodontal pathogenic bacteria in periodontal disease patients. However, due to the complex mechanism associated with periodontal disease and the limitations of the available studies, there is a further need for well-designed randomized clinical trials to assess the efficacy of probiotics.

Background: Amelogenesis, the formation of dental enamel, is well understood at the histomorphological level but the underlying molecular mechanisms are poorly characterized. Ameloblasts secrete enamel matrix proteins and Ca2+, and also regulate extracellular pH as the formation of hydroxyapatite crystals generates large quantities of protons. Genetic or environmental impairment of transport and regulatory processes (e.g. dental fluorosis) leads to the development of enamel defects such as hypomineralization.Aims: Our aims were to optimize the culture conditions for the three-dimensional growth of ameloblast-derived HAT-7 cells and to test the effects of fluoride exposure on HAT-7 spheroid formation.Methods: To generate 3D HAT-7 structures, cells were dispersed and plated within a Matrigel extracellular matrix scaffold and incubated in three different culture media. Spheroid formation was then monitored over a two-week period. Ion transporter and tight-junction protein expression was investigated by RT-qPCR. Intracellular Ca2+ and pH changes were measured by microfluorometry using the fluorescent dyes fura-2 and BCECF.Results: A combination of Hepato-STIM epithelial cell differentiation medium and Matrigel induced the expansion and formation of 3D HAT-7 spheroids. The cells retained their epithelial cell morphology and continued to express both ameloblast-specific and ion transport-specific marker genes. Furthermore, like two-dimensional HAT-7 monolayers, the HAT-7 spheroids were able to regulate their intracellular pH and to show intracellular calcium responses to extracellular stimulation. Finally, we demonstrated that HAT-7 spheroids may serve as a disease model for studying the effects of fluoride exposure during amelogenesis.Conclusion: In conclusion, HAT-7 cells cultivated within a Matrigel extracellular matrix form three-dimensional, multi-cellular, spheroidal structures that retain their functional capacity for pH regulation and intracellular Ca2+ signaling. This new 3D model will allow us to gain a better understanding of the molecular mechanisms involved in amelogenesis, not only in health but also in disorders of enamel formation, such as those resulting from fluoride exposure.

Background: A fixed combination of hawthorn and camphor (Korodin Herz-Kreislauf-Tropfen ® ) has been used in the therapy of hypotension for decades. Although its efficacy was evaluated in clinical trials, these studies have not been critically assessed in meta-analyses. Purpose: To systematically evaluate the efficacy of a fix combination of camphor and hawthorn extract (Korodin ® ) on blood pressure and cognition compared to placebo, in a meta-analysis based on randomized controlled trials (RCTs). Study design: The meta-analysis was carried out following the PRISMA guidelines, using the PICO format, and it was registered in the PROSPERO register. Methods: The Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of Science databases were searched for relevant studies. Placebo-controlled clinical studies involving adult patients receiving a fix combination of hawthorn extract and camphor were included. No language or publication year restrictions were applied. Results: Four randomized trials including a total of 221 patients were pooled for statistical analysis. According to the present meta-analysis, the fixed combination of hawthorn and camphor significantly increases systolic and diastolic blood pressure compared to placebo (p-values: 0.017 and 0.049, respectively) and had a beneficial, but not statistically significant effect on the cognitive performance in the connect-the-numbers test (p-value: 0.071). Conclusion: Korodin ® is an effective and presumably safe complementary therapy for the treatment of hypotension. Its blood pressure increasing effect is confirmed; however, the evidence supporting its use is very limited. The optimum dose and duration of treatment is still unclear. The comprehensive evaluation of efficacy and safety is required in further, high-quality clinical studies, involving larger patient populations and comparable endpoints.