ABSTRACT
Objective To investigate the effect of Iranian honey, cinnamon and their combination against Streptococcus mutans bacteria. Methods Nine experimental solutions were examined in this study, including two types of honey (pasteurized and sterilized), two types of cinnamon extract (dissolved in distilled water or dimethyl sulfoxide) and five different mixtures of cinnamon in honey (prepared by admixing 1%–5% w/w of cinnamon extract into 99%–95% w/w of honey, respectively). Meanwhile, each of mentioned agent was considered as the first solution while it was diluted into seven serially two-fold dilutions (from 1:2 to 1:128 v/v). Therefore, eight different concentrations of each agent were tested. The antibacterial tests were performed through blood agar well diffusion method, and the minimum inhibitory concentration (MIC) was determined. Ultimately, the data were subjected to statistical analysis incorporating Two-way ANOVA and Bonferroni post hoc tests (α = 0.01). Results The highest zone of inhibition was recorded for the mixtures of honey and cinnamon while all the subgroups containing 95%–99% v/v of honey were in the same range (P < 0.01). The MIC for both honey solutions were obtained as 500 mg/mL whereas it was 50 mg/mL for both cinnamon solutions. Moreover, the MIC related to all honey/cinnamon mixtures were 200 mg/mL. Conclusions A profound synergistic effect of honey and cinnamon was observed against Streptococcus mutans while there was no significant difference among extracts containing 99%–95% v/v of honey admixing with 1%–5% v/v of cinnamon, respectively.
ABSTRACT
Objectives: the aim of this study was to compare the microtensile bond strengths [micro TBS] of three core materials with one lithium disilicate reinforced ceramic using two resin cements
Methods: three core materials [Nulite F[registered sign] [Biodental Technologies], Filtek Z250[registered sign] [3M-ESPE], Prettau-Anterior[registered sign] [Zirkonzhan, Germany]] were prepared as blocks [10×10×4 mm3] according to the manufacturer's instructions. Lithium disilicate ceramic blocks were also constructed and bonded to core specimens with two dual curing luting resin cements [Duo-Link[registered sign] [Schaumburg, IL], Bifix QM[registered sign] [VOCO, Cuxhaven, Germany]]. Micro-bar specimens were prepared and loaded in tension to determine the micro TBS Failure modes were classified by scanning electron microscope [SEM]. Data were analysed using two-way ANOVA and Tukey HSD test
Results: the micro TBS varied significantly depending on the core materials and resin cements used [P< 0.05]. The micro TBS of Bifix QM was significantly higher than of Duo-Link in all core materials. The micro TBS of zirconia core was significantly higher than of both composite cores with both resin cements. There were no statistically significant differences among Nulite F and Filtek Z250 [P> 0.05]. The highest bond strength was obtained between zirconia core and Bifix QM [45.3 +/- 6.7 MPa]
Conclusion: in vitro micro TBS of glass ceramic blocks bonded to zirconia core material showed higher bond strength values than resin-based core material, regardless of the resin cement type used
ABSTRACT
Statement of the Problem: With the recent focus of researches on the development of non-invasive treatment modalities, the non-invasive treatment of early carious lesions by remineralization would bring a major advance in the clinical management of these dental defects. Casein phosphopeptide-amorphous calcium phosphate [CPP-ACP] is considered to be effective in tooth remineralization
Purpose: The aim of this in-vitro study was to compare the effects of whey and CPP-ACP in increasing the enamel microhardness
Materials and Method: Microhardness of 30 sound human permanent premolars was measured before and after 8-minute immersion of samples in Coca-Cola. The teeth were then randomly divided into 3 groups and were immersed in artificial saliva, whey, and tooth mousse for 10 minutes. The changes of microhardness within each group and among the groups were recorded and analyzed using paired t-test
Results: The microhardness increased in each group and between the groups; this increase was statistically significant [p= 0.009]
Conclusion: The effect of whey on increasing the enamel microhardness was more than that of tooth mousse
ABSTRACT
Objective: Nanosilver has numerous applications in medicine due to its potent antibacterial activity. However, data regarding the bio-safety of its effective concentrations is scarce. This study aims to assess the toxicity of silver nanoparticles on human gingival epithelial cells under in-vitro conditions
Methods: This in vitro study evaluated the toxic effects of filtered and unfiltered nanosilver solution on human gingival epithelial cells obtained from the Pasteur Institute of Iran using the methylthiazol tetrazolium bromide [MTT] assay [mitochondrial function]and membrane leakage of lactate dehydrogenase [LDH] at 24, 48 and 72h time points. The concentrations of silver nanoparticle solution used were 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 20 and 50micro g/ml
Results: The MTT assay showed that nanosilver solution at high concentrations [20 and 50micro g/ml] significantly decreased the viability of cells at all time points. The lower non-fatal concentrations at 24 and 48h were capable of causing cell death or significantly inhibit cell growth at 72h. The LDH assay demonstrated that death of epithelial cells only occurs at high concentrations of nanosilver [20 and 50micro g] and no significant toxicity was seen at lower concentrations
Conclusion: Based on the results, silver nanoparticles have toxic effects on human gingival epithelial cells and this effect is time and dose-dependent
ABSTRACT
The purpose of this study was research on a new herbal compound [Seidlitzia Rosmarinus] made by Traditional Medicine Research Group, University of Shahed to find a safer alternative to HCL-Pumice compound technique. In this randomized clinical trial seventy two anterior teeth from 9 patients were divided in to three groups according to fluorosis severity: mild [34 teeth], moderate [14 teeth], and sever [24 teeth]. In each patient, half of the teeth were treated with "Shahed" compound and other half treated with HCL-Pumice compound. Before and after treatment, photographs were taken in both groups. HCL-Pumice treatment compound was applied for 30 seconds periods and continued for 10 minutes if necessary. In case of herbal Shahed compound the time was determined by clinical symptoms or when labial contour was dismissed, If the result was not esthetistically acceptabale for the patient, HCL-Pumice compound was applied on teeth. NaF was applied after mouth washing. The photographs of the teeth before and after treatment were reviewed by two experienced observer unaware of the treatment modality. The results were analyzed using willcoxon's, kruskal-wallis and scheffe test. There was over 81.3% acceptance between two observers and no significant differences in intraobservers evaluation [P>0.05]. Improvement in beauty indexes were observed in all degrees of dental fluorosis by 18% with HCL-Pumice compound application, but "Shahed" herbal compound induced significant reduction in the amount of white spots in mild fluorosis and stain intensity of moderate fluorosis [P<0.05], while the reduction in the severity of discoloration in group 2, these two techniques were statistically equivalent but in the remainder, HCL-Pumice compound was more significantly effective [P<0.05]. HCL-Pumice compound reduces the severity of the discoloration of the teeth. Shahed herbal compound cannot reduces the discoloration like as HCL-Pumice compound
Subject(s)
Humans , Tooth Discoloration , Rosmarinus , Herbal MedicineABSTRACT
Metallic nano-particles show exclusive biological, chemical and physical characteristic. The purpose of this research was to evaluate the effect of various amounts of nanosilver incorporation [0 [as control], 20, 40, 80, 120, 200 ppm] on the mechanical Properties [compressive and flexural strength] of resin modified Glass ionomer Cement. Based on ISO 4049 and ISO 9971 for polyalkenoid cements, 90 cases in each group were prepared for the flexural and compressive strength. Specimens in 6 groups with different amounts of nanosilver [20, 40, 80, 120 and 200 ppm] and control [Fuji II LC improved], stored in distilled water at 37[degree sign] C for 1 day and 30 days. Flexural strength, using a three-point bending method, Modulus of elasticity and the compressive strength were measured by universal testing machine [Zwick] with crosshead speed of 0.5 mm/min. Data were analyzed using two-way ANOVA and Tukey post HOC test. The flexural strength and modulus of various amounts of nanosilver incorporation of resin modified glass-ionomer cement were not significantly different [P>0.05]. The compressive strength of incorporating of 20 ppm compared with control [P=0.01], 40 ppm [P=0.02] and 80 ppm compared with control [P<0.001] were increased. The flexural strength and compressive strength of Fuji II LC, containing nanosilver particles were increased after 1 day and 1 month significantly [P<0.001]. Incorporation of 20 to 80 ppm nanosilver into Fuji II LC had increased mechanical properties compared to the original cement
Subject(s)
Silver , Metal Nanoparticles , Compressive StrengthABSTRACT
The aim of this study was to evaluate the effect of dental surface treatment with Erbium-Doped Yttrium Aluminum Garnet[Er: YAG], Neodymium-Doped Yttrium Aluminium Garnet[Nd: YAG] and Carbon Dioxide Laser [CO[2]] lasers and sodium ascorbate to recently home bleached enamel by scanning electron microscope [SEM]. Thirty extracted human third molars were selected for this in vitro study. The teeth were randomly divided in two groups including home bleached group and control group [non-bleached]. In group 1, the samples were bleached by home bleach technique. No bleaching procedure was done in second the group which served as control group. Then, the samples of two groups were divided to five subgroups as follow: Subgroup 1: treated using Nd:YAG laser with output power of 1 W, Subgroup 2: treated using Er:YAG laser with output power of 0.5 W, Subgroup 3: treated using CO[2] laser with output power of 0.5 W, Subgroup 4: sodium ascorbate 10%, Subgroup 5: no treatment. After treatments, the surfaces were evaluated using Scanning Electron Microscope [SEM] analysis. The surfaces treated by Nd:YAG laser showed some melting and recrystallized areas and in some area droplet pattern was observed. But the surface treated by Er:YAG laser showed irregular and micro porous surface with flake pattern. CO[2] laser treatment of home-bleached surfaces resulted in melting area and cracks. Sodium ascorbate did not change the home-bleached surface. Among different surface treatments used in this study, it seems that Er:YAG laser can best interact with home-bleached teeth.
Subject(s)
Lasers, Solid-State , Lasers, Gas , Ascorbic AcidABSTRACT
Nano-sized hydroxyapatite nano particles [nHA] have optimal biological properties and by incorporating them into the restorative materials, we can benefit from these properties. The present study sought to assess the effect of incorporation of various amounts of nHA on the mechanical properties [compressive and flexural strengths] of a resin modified glass ionomer. In this experimental study, a total of 252Fuji II LC improved GI samples were divided into 6 groups including a control group [0%] and the nHA groups [1%, 2%, 5%, 7% and 10% based on mass percent]. Of the samples, 108 were fabricated for the flexural strength testing using a two-piece aluminum mold [2x2x25 mm] according to ISO standard 4049. In each group, a total of 18 samples in 3 subgroups [6 samples each] were fabricated. All samples were removed from the mold after 80 seconds of light irradiation. A total of 144 samples made for compressive strength testing using a two-piece brass mold [4x6 mm] according to ISO standard 9917. Thus, in each group, a total of 24 samples in three subgroups [8 samples each] were fabricated and removed from the mold after 80 seconds of light irradiation. After removal from the mold, all samples were stored in an incubator at 37°C and 100% moisture and underwent flexural and compressive strength testing with the primary load of 2 N and crosshead speed of 0.5 mm/min[-1] in a Zwick testing machine after one day, one week and one month. Data were analyzed using normal statistical tests of one-way ANOVA and Tukey's HSD [Post Hoc]. In order to assess the correlation of time [in groups with various mass percentages of HAP] with understudy outcomes, one way ANOVA was employed and P<0.05 was considered statistically significant. Study results showed that incorporation of 5% nHA resulted in a significant increase in flexural strength after 30 days [17.4 MPa increase][P<0.05]. Also, if the nHA weight percent exceeded 5%, flexural strength suffered a dramatic drop after one month[28.9 MPa reduction]. This study also showed that addition of 5% NHAP significantly increased flexural elastic modulus after one month [2.2 GPa increase]. Addition of NHAP to resin modified glass ionomer caused a small increase in compressive strength and compressive elastic modulus which was not statistically significant [about 1MPa increase]. Addition of nHA to resin modified glass ionomers [Fuji II LC improved] not only does not reduce compressive strength, but also can increase flexural strength which would be the greatest if nHA is added in an amount of 5%