Chemical Characterization and Cytotoxic/Antibacterial Effects of Nine Iranian Propolis Extracts on Human Fibroblast Cells and Oral Bacteria.

Multimicrobial infections caused by pathobionts are called dysbiotic multimicrobial illnesses. Commercial mouthwashes, such as chlorhexidine, have negative side effects that can prevent tooth decay and infection. The present study aimed to determine the antifungal, antibacterial, and cytotoxicity characteristics of the propolis extracts from different areas (Iran). The ethanolic extract of propolis was prepared. GC/MS carried out the characterization to determine the thymol, carvacrol, and menthol extracts, and also, total phenol and flavonoid were assed for all samples. The antimicrobial and antibiofilm effects were evaluated against S. mutans, S. mitis, S. salivarius, L. acidophilus, E. coli, S. aureus, and C. albicans. The cytotoxic effect of extracts was measured on human fibroblast cells by MTT test. The MIC values in mg mL-1 were ranged as follows: S. salivarius (0.003 to 0.048), S. mutans (0.003 to 0.029), S. mitis (0.007 to 0.058), L. acidophilus (0.007 to 0.117), C. albicans (0.014 to 0.234), E. coli (0.007 to 0.058), and S. aureus (0.007 to 0.058), while MBC were, respectively, S. mutans (0.007 to 0.058), S. salivarius (0.007 to 0.117), S. mitis (0.007 to 0.117), L. acidophilus (0.014 to 0.234), C. albicans (0.029 to 0.468), E. coli (0.014 to 0.234), and S. aureus (0.007 to 0.117). Cariogenic bacteria and Candida albicans were demonstrated to be resistant to propolis extracts. Therefore, propolis extracts may make good mouthwashes.

Evaluation of Cytotoxic and Antimicrobial Properties of Iranian Sea Salts: An In Vitro Study.

BACKGROUND: Dental caries is known as a multimicrobial disease. Caries are very prevalent in numerous countries, and the incidence is higher in underdeveloped countries than in developed countries. Dental caries is a major public health problem, and it is the most prevalent health problem across the world, affecting 2.4 billion people. Natural mouthwashes can be beneficial in the prevention of dental caries and oral infections without the side effects of synthetic mouthwashes. AIM: The aim of the present study was to investigate the antibacterial, antifungal, and cytotoxicity properties of sea salt from different areas of Iran. METHODS AND MATERIALS: Sea salts from different areas (Urmia, Qom, and Jarquyeh) of Iran were collected. In order to define the elemental and mineralogical features of different salt samples, X-ray powder diffraction (XRD) was employed. Different concentrations (0.19-50 mg/mL) of sea salt were used in the antimicrobial and antibiofilm tests. The antimicrobial (MIC, MBC, MFC, and DAD tests) and antibiofilm (formation and degradation tests) effects were evaluated against L. acidophilus, S. aureus, E. coli, S. mitis, S. mutans, S. salivarius, and C. albicans. The cytotoxic effect of salts was evaluated on human gingival fibroblasts by the MTT test. RESULTS: The range of MIC values in mg ml-1 was as follows: S. salivarius (50), S. mutans (50), S. mitis (50), L. acidophilus (12.5 to >50), C. albicans (50), E. coli (12.5 to 25), and S. aureus (12.5 to 25), while MBC values were, S. mutans (>50), S. salivarius (>50), S. mitis (>50), L. acidophilus (50 to >50), C. albicans (>50), E. coli (50), and S. aureus (50). MTT results showed that more than 50% of cell viability depends on decreasing the salt concentration (<1.56 mg/ml). CONCLUSION: Sea salts had significant antimicrobial effects on cariogenic bacteria and C. albicans. Therefore, sea salts can be a suitable candidate for mouthwash.

The Current Strategies in Controlling Oral Diseases by Herbal and Chemical Materials.

Dental plaque is a biofilm composed of complex microbial communities. It is the main cause of major dental diseases such as caries and periodontal diseases. In a healthy state, there is a delicate balance between the dental biofilm and host tissues. Nevertheless, due to the oral cavity changes, this biofilm can become pathogenic. The pathogenic biofilm shifts the balance from demineralization-remineralization to demineralization and results in dental caries. Dentists should consider caries as a result of biological processes of dental plaque and seek treatments for the etiologic factors, not merely look for the treatment of the outcome caused by biofilm, i.e., dental caries. Caries prevention strategies can be classified into three groups based on the role and responsibility of the individuals doing them: (1) community-based strategy, (2) dental professionals-based strategy, and (3) individual-based strategy. The community-based methods include fluoridation of water, salt, and milk. The dental professionals-based methods include professional tooth cleaning and use of varnish, fluoride gel and foam, fissure sealant, and antimicrobial agents. The individual-based (self-care) methods include the use of fluoride toothpaste, fluoride supplements, fluoride mouthwashes, fluoride gels, chlorhexidine gels and mouthwashes, slow-release fluoride devices, oral hygiene, diet control, and noncariogenic sweeteners such as xylitol. This study aimed to study the research in the recent five years (2015-2020) to identify the characteristics of dental biofilm and its role in dental caries and explore the employed approaches to prevent the related infections.

Comparison of antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times.

INTRODUCTION: Plaque accumulation can cause white spot lesions. Adding nanoparticles to composites can be effective in reducing the number and function of microorganisms. OBJECTIVE: The aim of this study was to evaluate the antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times. METHODS: Hydroxyapatite, titanium oxides, zinc oxide, copper oxide and silver oxide nanoparticles were prepared at 0.5% and 1% weight concentrations. Accordingly, ten study groups and one control group were obtained. Then, 26 composite discs were prepared from each group. Strain of Streptococcus mutans was cultured, and colonies of Streptococcus mutans were counted. Further bacterial culture was swapped onto enriched Mueller-Hinton agar. The composites were placed on the culture medium, and after incubation the diameter of growth inhibition was measured. To investigate the long-term effect of nanoparticles, the colonies were counted at days 3, 15 and 30. RESULTS: The results showed that 1% copper oxide and 1% silver oxide significantly reduced the number of bacteria (p< 0.05), but there was no significant difference between the other groups and control group (p> 0.05). At day three, there was a significant difference between control group and 0.5% silver oxide, 1% silver oxide and 1% copper oxide groups (p< 0.05). However, colonies had grown in all groups at day 30 but showed no significant difference with control group (p> 0.05). CONCLUSION: Addition of 1% copper oxide and 1% silver oxide has short-term antibacterial effects, so the clinical use of these nanoparticles cannot be justified.

Comparison of antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times

ABSTRACT Introduction: Plaque accumulation can cause white spot lesions. Adding nanoparticles to composites can be effective in reducing the number and function of microorganisms. Objective: The aim of this study was to evaluate the antibacterial effects of orthodontic composites containing different nanoparticles on Streptococcus mutans at different times. Methods: Hydroxyapatite, titanium oxides, zinc oxide, copper oxide and silver oxide nanoparticles were prepared at 0.5% and 1% weight concentrations. Accordingly, ten study groups and one control group were obtained. Then, 26 composite discs were prepared from each group. Strain of Streptococcus mutans was cultured, and colonies of Streptococcus mutans were counted. Further bacterial culture was swapped onto enriched Mueller-Hinton agar. The composites were placed on the culture medium, and after incubation the diameter of growth inhibition was measured. To investigate the long-term effect of nanoparticles, the colonies were counted at days 3, 15 and 30. Results: The results showed that 1% copper oxide and 1% silver oxide significantly reduced the number of bacteria (p< 0.05), but there was no significant difference between the other groups and control group (p> 0.05). At day three, there was a significant difference between control group and 0.5% silver oxide, 1% silver oxide and 1% copper oxide groups (p< 0.05). However, colonies had grown in all groups at day 30 but showed no significant difference with control group (p> 0.05). Conclusion: Addition of 1% copper oxide and 1% silver oxide has short-term antibacterial effects, so the clinical use of these nanoparticles cannot be justified.

RESUMO Introdução: O acúmulo de placa bacteriana pode causar lesões de mancha branca. A adição de nanopartículas nas resinas ortodônticas pode ser eficaz para reduzir o número e a função dos microrganismos. Objetivo: O objetivo do presente estudo foi avaliar os efeitos antibacterianos contra o Streptococcus mutans, em diferentes intervalos de tempo, de resinas ortodônticas contendo diferentes tipos de nanopartículas. Métodos: Foram criados dez grupos experimentais e um grupo controle contendo nanopartículas de hidroxiapatita, óxido de titânio, óxido de zinco, óxido de cobre e óxido de prata em concentrações de 0,5% e 1%. Em seguida, foram preparados 26 discos de resina para cada grupo. Colônias de Streptococcus mutans foram cultivadas e contadas. Posteriormente, as culturas bacterianas foram colocadas em solução de ágar Mueller-Hinton. Os discos de resina foram colocados no meio de cultura e, depois da incubação, mediu-se o diâmetro de inibição do crescimento. Para avaliar os efeitos em longo prazo das nanopartículas, as colônias foram analisadas após 3, 15 e 30 dias. Resultados: Os resultados mostraram que o óxido de cobre a 1% e o óxido de prata a 1% reduziram significativamente o número de bactérias (p< 0,05), mas não houve diferença estatisticamente significativa entre os outros grupos e o grupo controle (p> 0,05). Após 3 dias, houve uma diferença significativa entre o grupo controle e os grupos óxido de prata a 0,5%, óxido de prata a 1% e óxido de cobre a 1% (p< 0,05). Porém, após 30 dias, as colônias haviam crescido em todos os grupos, sem diferença com o grupo controle (p> 0,05). Conclusão: A adição de óxido de cobre a 1% e óxido de prata a 1% apresenta efeitos antibacterianos apenas no curto prazo; portanto, o uso clínico dessas nanopartículas não se justifica.

The Effect of the Er:YAG Laser and MI Paste Plus on the Treatment of White Spot Lesions.

Introduction: White spot lesions (WSLs) occurring after orthodontic treatment lead to patient dissatisfaction and aesthetic problems. The role of calcium-phosphate demineralization systems and the Er:YAG laser in the treatment of these lesions has recently been taken into account. This study aimed to investigate the effect of the Er:YAG laser and MI Paste Plus on the treatment of WSLs. Methods: A total of 65 premolars extracted due to orthodontic treatment were studied in this research. To create enamel lesions, the teeth were placed in a demineralizing solution. The teeth were then randomly divided into five groups (n=13) as follows: first group, control; second group, saliva; third group, MI Paste Plus; fourth group, Er:YAG laser; and fifth group, MI Paste Plus together with the Er:YAG laser. The teeth were kept in artificial saliva between treatment processes. Artificial saliva was replaced daily with fresh artificial saliva. The teeth were sectioned longitudinally by a disc from the middle of the exposed enamel and each section was mounted in polyester resin. The surface of the samples was serially polished and the microhardness of the teeth was measured at depths of 0, 50, 100, and 150 µm. Results: The microhardness was significantly higher in the fifth group than other groups at depths of 50 and 150 µm (P <0.005). Using the laser or MI Paste Plus alone did not significantly increase the microhardness. Conclusions: The combined application of the Er:YAG laser and MI Paste Plus is effective in the treatment of WSLs.