scholarly journals The Assessment Of The Antibacterial Effect Of Diode Laser Versus Nanosilver Fluoride On Streptococcus Mutans Count Of Oral Biofilm Of Primary Teeth

Author(s):  
Radwa Yehia Khater ◽  
2017 ◽  
Vol 8 (4) ◽  
pp. 197-200 ◽  
Author(s):  
Zahra Bahrololoomi ◽  
Reza Fekrazad ◽  
Shiva Zamaninejad

2019 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Dr. Maha Abdul- Kareem Mahmood ◽  
Dr. Huda Elias Ali ◽  
Dr. Haraa Khairi Abdul-Kadher

Microbes are considered as the primary etiologic agents in endodontic diseases.Disinfection of the root canal is obtained by the combined effect of biomechanicalpreparation, irrigation and intra canal medicament. The aim of the present study wasto assess the antimicrobial activity of intracanal medicaments (formocresol andEndosepton) against two micro organisms (Streptococcus mutans and staphylococcusaureus) isolated from 15 necrotic pulps of primary molars indicated for pulpectomyprocedure. The samples were cultured, and purified using microbiological evaluation.Broth dilution test was performed in our study by preparing test tubes containing10 ml of BHI broth (pH. 7) which then inoculated with strains of the tested bacteriaand incubated at 37 C° for 24 h. After over night incubaction, ten fold dilution weremade in test tubes containing 9 ml of normal saline by adding 1 ml of the inoculum tothe first tube . Then from dilution 10-1 , 0.1 ml of cell suspension was added to 9.9 mlof formocresol and endosepton, then 0.1 ml was taken and spread on duplicates ofBHI agar plates at different intervals and incubated aerobically for 24 h. at 37 C°.Colonies on the plates were counted after incubation and CFU/mL (colony formingunit) was calculated. Our results indicating that there were no significant differencesbetween the intracanal medicaments, but there were high significant differencesbetween the intervals time of the study. We concluded that both materials had greatantibacterial effect against the pathogens commonly isolated from necrotic pulpaltissue of primary teeth.


2021 ◽  
Vol 11 (7) ◽  
pp. 3232
Author(s):  
Jingyang Zhang ◽  
Sofiya-Roksolana Got ◽  
Iris Xiaoxue Yin ◽  
Edward Chin-Man Lo ◽  
Chun-Hung Chu

Studies have shown that silver diamine fluoride (SDF) is an effective agent to arrest and prevent dental caries due to its mineralizing and antibacterial properties. While plenty of studies have investigated the mineralizing properties, there are few papers that have examined its antibacterial effect on oral biofilm. The objective of this study was to identify the effect of silver diamine fluoride on oral biofilm. Method: The keywords used were (silver diamine fluoride OR silver diammine fluoride OR SDF OR silver fluoride OR AgF AND biofilm OR plaque). Two reviewers screened the titles and abstracts and then retrieved the full text of the potentially eligible publications. Publications of original research investigating the effect of SDF on oral biofilm were selected for this review. Results: This review included 15 laboratory studies and six clinical studies among the 540 papers identified. The laboratory studies found that SDF could prevent bacterial adhesion to the tooth surface. SDF also inhibited the growth of cariogenic bacteria, including Streptococcus mutans, Lactobacillus acidophilus, Streptococcus sobrinus, Lactobacillus rhamnosus, Actinomyces naeslundii, and Enterococcus faecalis, thus contributing to its success in caries arrest. One clinical study reported a decrease in Streptococcus mutans and Lactobacillus sp. in arrested caries after SDF treatment, and another clinical study found that SDF inhibited the growth of periodontitis microbiota, including Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia/nigrescens. However, three clinical studies reported no significant change in the microbial diversity of the plaque on the tooth after SDF treatment. Moreover, one laboratory study and one clinical research study reported that SDF inhibited the growth of Candida albicans. Conclusion: Not many research studies have investigated the effects of SDF on oral biofilm, although SDF has been used as a caries-arresting agent with antibacterial properties. However, a few publications have reported that SDF prevented bacterial adhesion to the teeth, inhibited the growth of cariogenic and periodontal bacteria, and possessed antifungal properties.


2017 ◽  
Vol 83 (22) ◽  
Author(s):  
Matthew De Furio ◽  
Sang Joon Ahn ◽  
Robert A. Burne ◽  
Stephen J. Hagen

ABSTRACTThe dental caries pathogenStreptococcus mutansis continually exposed to several types of stress in the oral biofilm environment. Oxidative stress generated by reactive oxygen species has a major impact on the establishment, persistence, and virulence ofS. mutans. Here, we combined fluorescent reporter-promoter fusions with single-cell imaging to study the effects of reactive oxygen species on activation of genetic competence inS. mutans. Exposure to paraquat, which generates superoxide anion, produced a qualitatively different effect on activation of expression of the gene for the master competence regulator, ComX, than did treatment with hydrogen peroxide (H2O2), which can yield hydroxyl radical. Paraquat suppressed peptide-mediated induction ofcomXin a progressive and cumulative fashion, whereas the response to H2O2displayed a strong threshold behavior. Low concentrations of H2O2had little effect on induction ofcomXor the bacteriocin genecipB, but expression of these genes declined sharply if extracellular H2O2exceeded a threshold concentration. These effects were not due to decreased reporter gene fluorescence. Two different threshold concentrations were observed in the response to H2O2, depending on the gene promoter that was analyzed and the pathway by which the competence regulon was stimulated. The results show that paraquat and H2O2affect theS. mutanscompetence signaling pathway differently, and that some portions of the competence signaling pathway are more sensitive to oxidative stress than others.IMPORTANCEStreptococcus mutansinhabits the oral biofilm, where it plays an important role in the development of dental caries. Environmental stresses such as oxidative stress influence the growth ofS. mutansand its important virulence-associated behaviors, such as genetic competence.S. mutanscompetence development is a complex behavior that involves two different signaling peptides and can exhibit cell-to-cell heterogeneity. Although oxidative stress is known to influenceS. mutanscompetence, it is not understood how oxidative stress interacts with the peptide signaling or affects heterogeneity. In this study, we used fluorescent reporters to probe the effect of reactive oxygen species on competence signaling at the single-cell level. Our data show that different reactive oxygen species have different effects onS. mutanscompetence, and that some portions of the signaling pathway are more acutely sensitive to oxidative stress than others.


2021 ◽  
Vol 18 (10) ◽  
pp. 105601
Author(s):  
Priscila Borges Gobbo De Melo ◽  
João Felipe Besegato ◽  
Adilson César Abreu Bernardi ◽  
Vanderlei Salvador Bagnato ◽  
Alessandra Nara de Souza Rastelli

2020 ◽  
Vol 23 (11) ◽  
pp. 1578
Author(s):  
TS Vinothkumar ◽  
R Apathsakayan ◽  
FM M El-shamy ◽  
HE Homeida ◽  
AIM Hommedi ◽  
...  

2016 ◽  
Vol 82 (7) ◽  
pp. 2187-2201 ◽  
Author(s):  
Xuelian Huang ◽  
Sara R. Palmer ◽  
Sang-Joon Ahn ◽  
Vincent P. Richards ◽  
Matthew L. Williams ◽  
...  

ABSTRACTThe ability of certain oral biofilm bacteria to moderate pH through arginine metabolism by the arginine deiminase system (ADS) is a deterrent to the development of dental caries. Here, we characterize a novelStreptococcusstrain, designated strain A12, isolated from supragingival dental plaque of a caries-free individual. A12 not only expressed the ADS pathway at high levels under a variety of conditions but also effectively inhibited growth and two intercellular signaling pathways of the dental caries pathogenStreptococcus mutans. A12 produced copious amounts of H2O2via the pyruvate oxidase enzyme that were sufficient to arrest the growth ofS. mutans. A12 also produced a protease similar to challisin (Sgc) ofStreptococcus gordoniithat was able to block the competence-stimulating peptide (CSP)–ComDE signaling system, which is essential for bacteriocin production byS. mutans. Wild-type A12, but not ansgcmutant derivative, could protect the sensitive indicator strainStreptococcus sanguinisSK150 from killing by the bacteriocins ofS. mutans. A12, but notS. gordonii, could also block the XIP (comX-inducingpeptide) signaling pathway, which is the proximal regulator of genetic competence inS. mutans, but Sgc was not required for this activity. The complete genome sequence of A12 was determined, and phylogenomic analyses compared A12 to streptococcal reference genomes. A12 was most similar toStreptococcus australisandStreptococcus parasanguinisbut sufficiently different that it may represent a new species. A12-like organisms may play crucial roles in the promotion of stable, health-associated oral biofilm communities by moderating plaque pH and interfering with the growth and virulence of caries pathogens.


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