جستجوی مقالات مرتبط با کلیدواژه « استرپتوکوک موتانس » در نشریات گروه « پزشکی »

Prescribing Chlorhexidine mouthwash is currently considered the standard anti-plaque treatment. One of the active antimicrobial compounds in the Iranian shallot extract is a flavonoid called Shalomin II. The purpose of this study was to compare the antibacterial effect of Shalomine II and Chlorhexidine on Lactobacillus acidophilus and Streptococcus mutans bacteria in human saliva.

Methods and Materials:

 In this in-vivo study, about 300 grams of white shallots were collected from Zagros Mountains. Then the aqueous extract was mixed with ethyl acetate (Razi, Iran) at a ratio of 50:50 and mixed for 10 minutes. Microbial resistance and antimicrobial sensitivity of microorganisms were determined using E-test. The bacteria investigated in this study were Lactobacillus acidophilus and Streptococcus mutans. A combination of 0.5% Shalomin II and 2 % chlorhexidine was prepared and diluted at eight different concentrations. The different mixtures were then cultured on the bacteria plate. This experiment was repeated three times. Then the plates were incubated at 37°C for 24 hours and examined for halo radius size. The location of the closed region indicated the minimum inhibitory concentration (MIC).

The MIC values associated with chlorhexidine against Streptococcus mutans and Lactobacillus acidophilus strains was 0.31 mg/mL and 0.16 mg/mL, respectively, and the MIC associated with Shalomin II against Streptococcus mutans and Lactobacillus acidophilus was 1.95 mg/ml. This difference was statistically significant (p=0.002). It was also found that the antibacterial effect of chlorhexidine was greater against Lactobacillus acidophilus compared to Streptococcus mutans.

Shalomin II had antimicrobial effects against both bacterial strains, and displayed a relatively similar inhibitory effect on Lactobacillus acidophilus and Streptococcus mutans. However, its inhibitory effect was not as strong as 0.2% chlorhexidine.

The thyroid gland is involved in the body's endocrine system and the synthesis of thyroid hormones (mainly triiodothyronine (T3) and thyroxine (T4)). These hormones play a vital role in regulating the basal metabolic rate and facilitating multiple metabolic processes in different organ systems. Stimulation of thyroid hormones refers to the fact that conditions such as hyperthyroidism often appear as a disorder of metabolic activity in various body systems, and its purpose is to meet the increased needs caused by excessive secretion of this hormone. The prevalence of thyroid disease in the world has a different situation and is influenced by environmental factors, especially iodine consumption. Iodine deficiency or excess in the body can cause a range of thyroid damage (from goiter and swelling of the thyroid gland to more serious conditions such as hyperthyroidism and hypothyroidism). Hyperthyroidism or thyrotoxicosis is characterized by an increase in the level of T3 or T4 in the bloodstream, and the occurrence of Grave's disease in these conditions often causes hyperthyroidism. On the other hand, hypothyroidism stems from insufficient hormone production, which causes symptoms such as fatigue, weight gain, and cold intolerance. This situation shows a decrease in the speed of the body's metabolism. In addition to the role of the thyroid gland, the oral microbiome (including billions of microorganisms such as bacteria, fungi, and viruses) plays an important role in local and systemic health. This complex microbial colony is responsible for the regulation of nutrient absorption, substance metabolism, and regulation of immune responses. Among a wide range of microorganisms, Streptococcus mutans and Streptococcus sobrinus stand out due to their serious participation in tooth decay through their acidogenic ability and biomembrane formation. The relationship between oral health and thyroid diseases, such as infectious thyroiditis, emphasizes the relationship between oral and systemic health. Infectious thyroiditis can be caused by bacterial infections of the oropharynx. This situation shows how oral microbial imbalance can have systemic consequences. Also, the accumulation of some bacteria in the oral cavity, such as Streptococcus mutans and Streptococcus sobrinus bacteria, is effective not only in local tooth decay but also in the aggravation or potential impact of systemic conditions. Saliva contains organic and inorganic ions and has essential functions in the oral cavity, such as maintaining the moisture of the oral mucosa, neutralizing acids or bases, and protecting against demineralization. The ability of these bacteria to metabolize sugars into organic acids demineralize tooth enamel cause tooth decay, and contribute to inflammatory processes that affect the body in a wide way. Streptococcus mutans is a remarkable case for the synthesis of extracellular glucan polymers with the help of sucrose due to its role in the formation of biomembranes on tooth surfaces. This process can facilitate the adhesion of bacteria to dental surfaces and its persistence in the oral cavity the transmission of Streptococcus mutans from mother to infant, which is mainly through saliva, shows the importance of oral hygiene. The resilience of these bacteria is characterized by their ability to grow in acidic environments, and this feature allows them to be stronger than other microbial species and dominate the biological membrane. Diagnosis of Streptococcus mutans usually depends on selective media, growth on Mitis salivarius agar, colony morphology, and biochemical characteristics. Also, the SB-20M medium is a selective medium for direct morphological identification and detection of Streptococcus mutans and Streptococcus sobrinus and has the necessary efficiency. The pathogenesis of Streptococcus mutans involves complex mechanisms for sensing environmental conditions and regulating gene expression to adapt to fluctuations in pH, nutrient availability, and host immune responses. This adaptive capacity emphasizes the role of bacteria in oral health and its potential implications for systemic health conditions such as thyroid disorders. Similarly, although less studied, Streptococcus sobrinus shares many of the virulent features of Streptococcus mutans that exacerbate dental caries.Thyroid hormones play an important role in maintaining oral and dental health, and their imbalance can cause various oral injuries. This study aims to evaluate the relationship between the serum levels of thyroid hormone (FT3, FT4 and TSH) and the number of live pathogens in oral saliva (Streptococcus mutans and Streptococcus sobrinus) in patients with thyroid disorders (hypothyroidism and hyperthyroidism) compared to the control group.

A "case-experimental" study was conducted on 58 patients with thyroid disorders (29 with hypothyroidism and 29 with hyperthyroidism) and 29 healthy people as a control group. The subjects were between 30 and 60 years old, and saliva samples were collected for microbial count and serum samples were also collected to determine the concentration of FT3, FT4, and TSH.

The results of the comparison between the hyperthyroid and control groups show that there is a significant difference at the P>0.01 level in terms of the studied thyroid hormones, and for the comparison between the hypothyroid and control groups, it was also determined that there is a significant difference at the P>0.01 level regarding the TSH hormones. While there was no significant difference at the level of P>0.05 with other comparisons. For the comparison between the hyperthyroid and hypothyroid groups, the results show that there is a significant difference at the P<0.01 level according to the studied thyroid hormones. These results are consistent with the observations of previous researchers. This situation showed that there is a significant difference in fT4 and TSH levels between the control group and hypothyroid patients. Various research studies have been able to express the relationship between salivary function and numerous systemic diseases. There is a strong connection between salivary function and joint diseases (such as thyroid dysfunction, which is one of the most common endocrine disorders). The results of this study show that there is a significant difference at the P<0.01 level between hyperthyroid patients and the control groups regarding SFR and also among the patient groups, while there was no significant difference at the P>0.05 level between the hypothyroid patients and the control groups. . This indicator is too sensitive due to hyperthyroidism. This study showed a decrease in SFR in the study group compared to the control group. Decreased salivary flow is associated with decreased buffering capacity and causes disturbances in the clearance of oral sugar and increases the risk of severe dental caries in people with thyroid dysfunction. According to the results obtained by Al-Naif and El-Soud (2013), there is a decrease in SFR among patients with hyperthyroidism. This study showed that patients with hyperthyroidism had lower salivary flow rate (SFR) compared to the control group, and patients with hypothyroidism also had higher SFR levels compared to the control group (P<0.05). The number of viable salivary Streptococcus mutans and Streptococcus sobrinus had a significant difference in patients with hypothyroidism and hyperthyroidism compared to the control group.

This study concluded that although thyroid disorders greatly alter hormone levels, they have no effect on salivary levels of Streptococcus mutans and Streptococcus sobrinus, and this means that there is a complex relationship between thyroid health and the oral microbiome that needs to be further evaluated.

Polish and glaze are 2 methods to decrease roughness and bacterial adhesion to the ceramic surfaces. This in vitro study assessed the effect of polish and glaze on the bacterial adhesion of 3 ceramics.

In this in vitro trial, samples of zirconia-reinforced lithium silicate, lithium disilicate and monolithic zirconia ceramic specimens were milled by CAD/CAM device from the blocks and sintered in the oven. The specimens were polished, glazed or remained intact with no preparations as a control group. The specimens' surface roughness were assessed by a profilometer followed by exposing to streptococcus mutans bacterium. The bacterium suspension were inoculated in wells containing tryptic soy broth + 0.2% glucose and ceramic specimens were placed into the wells. The plates were incubated for 48 hours at 37C° to form biofilms on the specimens. After washing, biofilm fix and ethanol removal, 1ml 0.4% crystal violet dye were added. The dye was removed and after washing, 1mm 30% acetic acid was added and 200 µl of the wells containing were transferred to a 96-well plate.The observations of streptococcus mutans adhesion to ceramic specimens were done by SEM.  Two-way analysis of variance was used for evaluation of ceramic type and preparation effects and one-way variance and tukey tests were used for intragroup evaluations.

In the Zolid ceramics, significantly higher bacterial adhesion were noted in the glazed than polished specimens (p=0.005). In the glazed specimens, significantly higher bacterial adhesion were noted in the Zolid ceramic than Suprinity (p=0.01) or IPS.Emax (p=0.009) ceramics.

Then, the surface preparation method showed significant effect on the bacterial adhesion only in Zolid ceramic. Except to polished Zolid ceramics, all ceramics and preparation techniques showed bacterial adhesion.

Dental caries is an infections disease leading as dynmic process with attack (demineralization and compensation (remineralization) of dental material.The aim of this study to evaluate the antibacterial effect of two dentin desensitizers, Vocco Bifluoride 10 and MI paste, on the cariogenic bacteria Streptococcus mutans, Streptococcus sabrinus and Lactobacillus acidophilus.

In this experimental laboratory study, samples of Streptococcus mutans, Streptococcus sabrinus and Lactobacillus acidophilus were used. From each of the compounds of Bifluoride 10 and MI paste 3 discs and 6 culture media for each bacterium were prepared. After drying and sterilizing the disks, the quality control operations of the disks were performed and cultured in culture media at 37 ° C for 48 hour. According to the antimicrobial halo around each disk, its measurement the growth or non-growth of bacteria was examined. Data were analyzed using t-test and two-way ANOVA

In inhibition of streptococcus mutans, Biflooride 10 was more effective, significant. (P=0.029) and in line with streptococcus sabrinus, poste ml was more effective (P=0.003).

The use of Bifluoride and MI paste is effective on diameter of the non-growth halo of cariogenic bacteria Streptococcus mutans, Streptococcus sabrinus and Lactobacillus acidophilus and therefore but MI paste had more effect in elimination of carigenic bacteria.

Due to the increased demineralization risk of enamel adjacent to fixed orthodontic attachments by cariogenic bacterias (e.g. Streptpcoccus mutans, Streptpcoccus sobrinus) and lack of adequate data about commonly used orthodontic cements, we decided to evaluation the antibacterial effects of three common domestic and foreign orthodontic cements (Glass ionomer, Zinc phosphate, and polycarboxylate) on two cariogenic pathogens (S.mutans and S.sobrinus).

In this in vitro study, direct contact test was utilized for evaluating cementschr('39') antibacterial effect after biphasic culturing and concentration adjustment of S.mutans and S.sobrinus. Groups (n = 5) included: three types of glass ionomer resilience cements, Hoffman’s zinc phosphate and Hoffman’s polycarboxylate and three glass ionomer cements, zinc phosphate and carboxylate from Aria Dent factory in Iran. Acquired data were analyzed using SPSS 20.

Ethical Considerations:

 MUBABOL.REC.1391.7.

Regarding to zone of inhibition, there was statistically significant difference between three tested cements in both S.mutans and S.sobrinus culturing media (p<0.001). The mean diameter of inhibition zone was greater for Iranian polycarboxylate compared to its foreign counterpart (p<0.001).

Glass ionomer cement demonstrated better antibacterial effect compared to zinc phosphate and polycarboxylate cements. There was also greater antibacterial effect of three tested cements on S.sobrinus than S.mutans. Iranian polycarboxylate showed stronger inhibition on both mentioned bacterias compared to the foreign one.

Since orthodontic removable appliances might be infected with fungi and bacteria, they need to be cleaned using natural disinfectants and chemicals. This study aimed to compare the clinical impact of thyme essence and Fluconazole solution on the amount of Candida albicans colonies and Streptococcus mutans accumulated on the removable appliances in orthodontic patients.

In this descriptive-analytical study, 21 patients were selected who used the wear Hawley’s retainer for 24-hours. Patients were divided into three groups of seven. One group first washed the plaque with soap and water and then spray thyme essence all over it at a 5-centimeter distance (4 times on each side). In the other group, as before, the plaque was washed and from the same distance as before, the fluconazole solution (10 mg/ml) was sprayed on all surfaces 4 times. In the control group, the retainer was washed every night only with soap and water. After one month, the retainers were delivered form patients. The two samples were then separated from the Kami platelets and sent to a laboratory for microbial culture. Data were analyzed by Mann-Whitney, T-test (α = 0.05).

The use of thyme essence increases the mean area of Candida albicans inhibition, which was significantly higher than that in the control group (p value = 0.03). The effect of Fluconazole solution on this mean area) Candida albicans inhibition zone( was not significant compared to that observed in the control group (p value = 0.5). In the group in which thyme essence was used, the mean area of Streptococcus mutans inhibition, which was significantly higher than that in the control group (p value = 0.05). When Fluconazole solution was used, the mean area of Streptococcus mutans inhibition, was not significant compared to that observed in the control group (p value = 0.071).

Compared to Fluconazole solution, thyme essence functions more effectively in increasing Candida and Streptococcus mutans inhibition zones.

Nowadays, new techniques are used to control dental caries that have the ability to kill cariogenic bacteria. Recently, the addition of antibiotics to glass ionomers has been proposed to reduce the overall number of saliva bacteria. The aim of this study was to compare the antimicrobial effect and compressive strength of resin- modified glass ionomer (RMGI) containing different antibiotics on Streptococcus mutans.

A total of 120 specimens were prepared in 3 groups (n=40) including RMGI containing doxycycline with a concentration of 1.5%, RMGI containing a combination of ciprofloxacin, metronidazole and minocycline with a concentration of 1.5%, and RMGI without antibiotics as control group. To measure the antibacterial effect, the disk diffusion method and counting of Streptococcus mutans bacterial colonies were used and then the compressive strength test was performed. Data were collected into SPSS25 and analyzed by ANOVA and Kruskal-Wallis tests and the significance level was considered α=0.05.

The mean number of bacterial colonies in the RMGI group containing doxycycline in all three time intervals 1, 24 hours and 7 days was significantly lower than the specimens in the RMGI group containing the triple antibiotic (P<0.001). The mean compressive strength of the two experimental groups was lower than the control group but was not statistically significant (P=0.326).

The addition of antibiotics at a concentration of 1.5% to RMGI resulted in a favorable antibacterial property with no significantly change in the compressive strength.

Resistance of oral pathogenic bacteria to chlorhexidine mouthwash is increasing; therefore, researchers are looking for a replacement of chlorhexidine with suitable herbal mouthwash. This study aimed to investigate the antimicrobial effect of hydroalcoholic extract of Plantago major (a native strain of Khorasan, Iran) with and without zinc oxide nanoparticles on Streptococcus mutans.

In this in vitro study, the samples were tested in two groups of hydroalcoholic extract of Plantago major leaves with and without zinc oxide nanoparticles. To determine the minimum bactericidal concentration and minimal inhibitory concentration, agar diffusion and broth dilution methods were applied, respectively. A concentration of 500 ppm zinc oxide nanoparticles with a 0.4 nm diameter was used continuously in all stages of the experiment. The materials used in this study consisted of a standard strain of Streptococcus mutans (ATCC 25175), chlorhexidine 0.2% as a positive control, and distilled water as a negative control.

The mean diameter of the growth inhibition zone was obtained as 15±1 mm for the hydroalcoholic extract of Plantago major leaves with zinc oxide nanoparticles at a concentration of 1.56 mg/ml. The same extract at the same concentration, however without zinc oxide nanoparticles, showed the mean diameter of growth inhibition zone of 7.67±0.57 mm. The results of the t-test were indicative of a significant difference between the two groups (P-value<0.001).

In this study, the antimicrobial effect of Plantago major leaves extract with or without zinc oxide nanoparticles was well established. This research is peculiar since it revealed the effectiveness of low concentrations of this plant in killing Streptococcus mutans.

Increased bacterial (streptococcal) biofilm aggregation on the surface of resin composite restorations in comparison with amalgam and glass ionomer restorations makes the composite restorations susceptible to secondary caries next to the restorations.  In this study, the anti-Streptococcus mutans properties of resin composites containing silver nanoparticles were investigated.

In this experimental - laboratory study, using turbidity (spectrophotometry) test, the anti-streptococcus mutans properties of resin composites containing 0, 0.02, 0.03, 0.04, 0.05% w/w of nanosilver particles, were investigated. the composites were adapted on the wall surfaces of 400µl microplates, and after curing or stiffening (by light curing apparatus), they were exposed to the bacterial suspension in broth medium. After 3, 24, and 48 hours, the optical density of the broth was read by spectrophotometer.

The results of the one-way analysis of variance showed that optical density (index of bacterial proliferation) in the composites containing silver nanoparticles with concentration of 0.03% w/w significantly decreased at times of 3 h (0.080±0.0009), 24h (0.079±0.0013), and 48 h (0.079±0.008) in comparison with composites without silver nanoparticles (0.089±0.005, 0.094±0.005, and 0.101±0.009, respectively), which is indicative of significant decrease in bacterial proliferation. This antibacterial effects did not increase in composites containing 0.04 and 0.05 % w/w concentrations of silver nanoparticles.

The results of this study revealed that all groups of the composite containing silver nanoparticles have antibacterial effect. Furthermore, optimal antibacterial effect exists in groups containing silver nanoparticles with concentration of 0.03% w/w.

Polymerization shrinkage causes a gap between the composite resin and the tooth edge which leads to bacterial invasion, secondary caries, recurrent caries, and the final failure of restoration. It seems that the addition of nanoparticles to composites can be effective in the reduction of the number and function of microorganisms. The aim of the present study was to compare the antibacterial properties of composite resins containing zinc-oxide with copper-oxide nanoparticles against Streptococcus mutans.

A number of 490 discoid tablets containing 0.05%,0.5%, 0.1% nano-copper and nano zinc-oxide particles were prepared from composite resin GC (n=70). Diluted solutions of Streptococcus mutans (ATCC 35668) were prepared and 1 mL of bacterial species was placed on the discs. The discs were transferred to liquid culture media and were incubated at 37℃ for 8 hr. Thereafter, 1 mm of serum was cultured at 37° C for 24 hours on a blood agar containing sheep blood and the total number of bacteria was obtained by colony counting of all bacteria detected on each disk. The data were analyzed in SPSS software (version 17) using Kolmogorov-Smirnov test (k-s), Kruskal-Wallis, and Dunn's test. The significance level was considered as α = 0.5.

Based on the obtained results, the composites containing 0.1% and 0.5% Nano zinc oxide particles and copper oxide nanoparticles significantly decreased the number of bacteria in 15 and 30 days, as compared to the control group (P-value=0.001). Nonetheless, other groups did not demonstrate any significant difference with the control group (P-value=1).

Composite resins containing 0.5% zinc oxide nanoparticles demonstrated the highest antibacterial activity against Streptococcus mutans. On the other hand, both nano-copper and zinc-oxide particles revealed the least antimicrobial activity in the concentration of 0.05%.

With spreading orthodontic treatments and mouth flora change during orthodontic treatment and increasing of white lesions around orthodontic appliances in patients undergone orthodontic treatments and also controversial reports about the different brackets types and their effect on adhesion of streptococcus mutans, this study aimed to compare the effect of different orthodontic bracket (metal, ceramic, self -ligating) on growth and adherence of streptococcus mutans.

This experimental Invitro study was accomplished on 60 samples. Three types of brackets (metallic, ceramic and self ligating) related to premolars were used for comparison of streptococcus mutans adhesion. Each of the brackets were placed into tubes containing 15cc of sterile Nutrient broth with %20 sucrose. Then 5cc of bacterial suspension were added to each plates. Plates were incubated for 5 days at 37°C. Then, after removal of the nutrient broth liquid from plates, plates upside down and the number of colonies attached to the plate was counted by eye according to Colony forming unit (CFU) and. Data were analyzed by ANOVA test.

The study was done by 60 samples including three types of metal, ceramic and self ligating brackets. The results of the study showed that the maximum streptococcus mutans adhesion was belonged to self ligating brackets (51.25±15.01), metal brackets (21.8±7.1) and ceramic brackets (15.5±3.6), respectively and the difference between three gourps was significant (P<0.001).
 

The growth and adhesion of Streptococcus mutans is different in the presence of various orthodontics bracket material and bracket designs.  The most and the least  Adhesion of streptococcus mutans was in self ligating and the ceramic  brackets adhesion had least streptococcus mutans, respectively

Many bacteria are involved in dental plaque formation and caries. Streptococcus mutans is one of the most important bacteria involved in this case. One of the ways to control plaque is the use of mouthwash on the side of toothbrushes and toothbrushes. Although chlorhexidine is the most effective mouthwash against oral microorganisms, the side effects of long-term use suggest the need for an alternative. The purpose of this study was to compare the antibacterial effect of nanosilver and chlorhexidine mouthwash on Streptococcus mutans in pediatric ward of Dental School of Islamic Azad University of Tehran and Laboratory of Veterinary School of Tehran University in 1397-1398.

This experimental study was performed in vitro on Streptococcus mutans. Experiments were performed on two groups of case (nanosilver mouthwash) and control (chlorhexidine mouthwash) in three parts. Antimicrobial potency was measured by Disk diffusion assay by measuring inhibitory zone diameter. Then both micro and macro dilution methods were used to measure MIC (Minimum bacterial growth Inhibitor Concentration) and finally for measure MBC (Minimum Bactericidal Concentration) using Blood agar dilution method.

Statistical analysis showed that the nanosilver mouthwash has no inhibitory zone and MBC. Also its MIC was higher than chlorhexine and this difference was statistically significant (P <0.001).

According to the results of the in vitro study of nanosilver mouthwash compared to chlorhexidine, it has minor bacteriostatic properties and no bactericidal effect. It is recommended to repeat this study by changing the mouthwash formulation in terms of particle concentration and diameter.

Mouthwashes are one of the tools used to reduce decay. Fluorin total mouthwash is a new mouthwash, so far no research has been done on its effect on streptococcus mutans.
In this study, the diameter of growth inhibition zone for streptococcus mutans bacteria was compared between fluorin total and chlorhexidine mouthwash. First, we cultured the bacteria on blood agar and incubated for 24 hours at 37° C. Then, we cultivated it on 21 blood agar plates. We randomly put one chlorhexidine disk on 10 plates and one fluorin total disk on other 10 plates. We also placed antibiogram disk and a blank disk without mouthwash on 1 plate. We placed the plates at 37° C for 24 to 48 hours into the incubator and then measured the growth inhibition zone.
The growth inhibition zone in the chlorhexidine and fluorin total group was 15.4 mm and 11.4 mm, respectively, which was 4mm higher in the chlorhexidine group,which is statistically significant.
Due to the complications of chlorhexidine mouthwash, this mouthwash cannot be used on a daily basis. It seems that fluorin total mouthwash can be used as an auxiliary method for those who are at high risk of decay.

Consumption of food causes changes in oral flora. Foods that create an appropriate media for Streptococcus mutans and other cariogenic microflora, cause increase the rate of tooth caries. The aim of this study was the assessment of short-term consumption of probiotic cake (contain Bacillus coagulans) on salivary streptococcus mutans count and comparison with ordinary cake. A cross over blind study was conducted on 30 healthy adult volunteers in two groups (16 males and 14 females). The first group ate probiotic cake (75 grams daily) for 1 week and after 2 weeks wash out period, they ate ordinary cake. The second group first ate ordinary cake and after 2 weeks wash out period, they ate probiotic cake (75 grams daily). Non-stimulating salivary samples, before (as baseline) and after eating probiotic and ordinary cake, were collected. Then counting of streptococcus mutans was done with colony counter. FINDINGS: Of the 30 patients, 16 (53.33%) were male and 14 (46.67%) were female with an average age of 40.86±17.15 years. Number of Streptococcus mutans in baseline saliva samples was (7.872±1.430)106 CFU/ml and in the saliva samples after consumption of probiotic cake was (4.652±0.841)106 CFU/ml and in saliva samples after consumption of ordinary cake was (21.386±3.895)106 CFU/ml. There was no significantly difference between mutants count before and after eating probiotic cake (p=0.769) but after consumption of ordinary cake than probiotic cake the count of streptococcus increased significantly (21.3±39.9 compared with 4.65±0.84) (p=0.032). Based on the results of this study, the addition of probiotic bacteria to sweet and high-consumption foods can reduce the adverse effects of foods such as cakes on oral health.

Several studies have reported the antibacterial effect of Teucrium polium extract. In this study, we sought to determine the effect of a chewing gum containing the aqueous extract of Teucrium polium on the level of salivary Streptococcus mutans.
In this double-blind clinical trial, 20 dental students were randomly assigned to two groups of intervention and control. The intervention group received a chewing gum containing the aqueous extract of Teucrium polium, and the control group received a chewing gum without any plant extract. Each person chewed the gum for 20 minutes three times a day (after each meal) for three weeks. Unstimulated saliva samples were collected at the beginning of the experiment before the use of the gums and one day after the final gum consumption. The quantitative polymerase chain reaction (qPCR) technique was employed to determine the bacterial level. The colonization rate of Streptococcus mutans was compared between the two groups by using t-test in SPSS, version 21.
There was no significant difference between the two groups in terms of Streptococcus mutans counts before the intervention (P>0.05). The consumption of Teucrium polium extract-containing chewing gum in comparison with the placebo gum significantly diminished the number of Streptococcus mutans colonies (P=0.002).
The results of this study showed that the chewing gum containing the aqueous extract of Teucrium polium significantly lowered the colonization rate of Streptococcus mutans in human saliva.

Background and Improvement of anti-bacterial properties of restorative materials to deal with microbes causing secondary caries of tooth has attracted interest of many researchers. Thus, in this study the antibacterial effect of zinc phosphate nanoparticles, synthesized with biological method, was investigated by adding it to glass ionomer cement against the Streptococcus mutans.
Synthesis of the nanoparticles was carried out using two main sources of zinc nitrate and diammonium hydrogen phosphate in presence of Enterobacter aerogenes. Furthermore, their antimicrobial effect was investigated by adding different concentrations of nanoparticles (0, 1, 2, 3, and 5%) to glass ionomer. In addition, bacterial cultures of 0.5 McFarland and its medium were added to the above mixture and were incubated in 37ºC. After 3, 6, and 24 hr they were cultured on agar plates to grow. In the end, the number of bacterial colonies grown on the plates was counted and compared.
Adding nanoparticles to glass ionomer improved its antibacterial effect and this effect enhanced when the concentrations of nanoparticles increased.
Synthesized nanoparticles are appropriate to be added to the glass ionomer cements because of their impressive effect on inhibiting the growth of bacteria and sharing same coloring with teeth.

Dental caries is an infectious disease transmitted by multiple factors in the mouth and one of the most common chronic diseases in the world that requires a lot of treatment expenses. The aim of this study was to evaluate the effect of fluoride 0.2% and Fuchs mouthwash (a combination of xylitol and fluoride 920 ppm) against two bacterial growths (Streptococcus mutans and Lactobacillus acidophilus).
In this in vitro study, first the well diffusion method and then MIC method (minimum inhibitory concentration) were used. Data were analyzed with Excell (2016).
The results of the MIC method showed inhibitory effect of both mouthwashes in pure concentration (128 μg/ml). However, fluoride was effective in concentration higher than 32 μg/ml for Streptococcus mutans and higher than 2 μg/ml for lactobacillus acidophilus. Fuchs was effective for both bacteria at concentration higher than 64 μg/ml and in lower concentration it was ineffective. The results of the well diffusion test showed the inhibition of fluoride mouthwash in pure concentration on the Streptococcus mutans was (17 mm) and on the lactobacillus acidophilus 24 mm was obtained. In Fuchs mouthwash was zero and it represented effectiveness of fluoride on bacteria and ineffectiveness of Fuchs.
The fluoride mouthrinse in different concentrations, because of having a good inhibitory effect in both methods on Streptococcus mutans and Lactobacillus acidophilus was more effective compared with that of Fuchs mouthrinse.

Early childhood caries (ECC) is one of the most common problems in children worldwide which is seen in 3-45% preschool children population. Bacterial factor is one of the main four components (time, microorganism, diet, host) to create caries. Streptococcus mutans is one of the most important cariogenic microorganisms. The objective of this study is evaluating Streptococcus mutans count in children with ECC and caries free children considering other factors. The aim of this study was to find the CFU of Streptococcus mutans in saliva of children with ECC versus caries free ones. In addition environmental factors affecting CFU of this micro organism.
Salivary Streptococcus mutans count in 76 3-5 year old children was done in two groups (ECC and caries free). Non stimulated saliva was collected and cultured on Streptococcus mutans specific growth medium. Data was analyzed with Chi-Square, spearman, Kruskal–Wallis,Mann–Whitney tests.
Differences in colony count in study groups were statistically significant and was less in caries free children (p value In the current study, a statistically significant difference was seen in colony count in two groups. Sugar consumption frequency and feeding method had a significant impact on colony count. Micro organisms are still the most important factors in creating caries but feeding pattern and sugar consumption frequency also have an important role. The results also showed that parents educational level does not influence reducing caries which should be noted.