ABSTRACT
Objective: Bioactive glass 45S5 is a surface reactive glass-ceramic biomaterial, developed in 1969. BAG 45S5 with particle size of 20-60 nm has the ability of bone regeneration, broad spectrum antibacterial effect, repairs and replaces diseased or damaged bone. The aim of this study was to evaluate the antibacterial activity and determine MIC and MBC values of nano-BAG45S5 on Streptococcus mutans
Methods: In this study the in vitro Antibacterial activity of polycrystalline and glass forms of nano- BAG 45S5 was evaluated. Bacterial susceptibility to test materials was examined by antibiogram test. Afterwards MIC and MBC assays were conducted via broth dilution, disc diffusion and colony count methods
Results: Despite amorphous nano-BAG 45S5, poly-crystalline form had antibiogram negative test result. In broth dilution test, the optical absorbance of test dilution of 50mcg/ml and higher concentrations were equal to negative control's optical absorbance and their inhibitory zone diameter were measured 10.0mm in disc diffusion test. No colony was observed on the culture media of test dilution of 200mcg/ml and higher concentrations
Conclusion: Streptococcus mutans [ATCC 35668] is not susceptible to poly-crystalline nano- BAG45S5. Amorphous nano-BAG45S5 is bacteriostatic against Streptococcus mutans. MIC and MBC values for amorphous nano-BAG45S5 were 50 ppm and 200 ppm, respectively
ABSTRACT
Discovery, purification and synthesis of Bone Morphogenetic Proteins [BMP] were an important turning point in understanding of bone physiology for repair of bone defects. The present study aimed at eliminating the limitations caused by the application of bone auto-grafts and finding a proper substitute for bone grafts. This study was the first to evaluate the effect of BMP7 and nanosilver particles on the permeability of muscle cells for ectopic bone formation in Rat gluteofemoral muscle. This experimental double blind study was conducted on 42 rats divided into 6 groups of 7 each. The first 3 groups received an injection of 200 ng BMP7 with 0.1 mg nanosilver particles and the remaining 3 groups received 200 ng BMP7 in 0.4 mg normal saline. Rats were euthanized 7, 14 and 21 days post-operation and evaluated in terms of presence of tissue changes like necrosis, inflammation, and formation of fibrous or calcified tissue under a light microscope with X40, X100, and X400 magnification. The obtained results were analyzed with Hosmer-Lemeshow, chi square and Wilcoxon tests. Results of the 2 groups were analyzed and compared using Mann Whitney U and Kruskal-Wallis tests. No statistically significant differences were detected between the subgroups of our 2 main understudy groups in terms of bone formation, distribution of inflammation [P=0.439], the amount of inflammation [P=0.743] and presence or absence of foreign body [P=0.381] over time. However, the two groups of BMP7 + nanosilver and BMP7 alone showed significant differences over time. Rats do not have sufficient number of efficient receptors for BMP7 in muscle tissue. Even by using nanosilver particles for increasing the permeability of cells, BMP7 was not able to induce muscle cell differentiation to initiate calcification process
ABSTRACT
Hydroxyapatite [Ca[10][PO][4][6][OH][2] is the major inorganic component of hard tissues, the best bio-active materials, which is compatible with the bone tissue. In addition, hydroxyapatite nanoparticles [Nano-HA] have received enormous national attention in medical and dental applications recently; but the ultimate fate of the Nano-HA within the body is still unknown. Degradation products of nanomaterials are potentially cytotoxic. Thus, it is essential to assess biocompatibility before their usage in clinical applications. Purpose of this research is to evaluate toxicity of hydroxyapatite nano particles on the human peripheral blood mononuclear cells. In this experimental study, nano sized, rod-like hydroxyapatite particles sterilizalied then HPBMCs were cultured on 96-well plate. Cells were exposed to Nano-HA at the following concentrations: 15.5, 32, 65, 125, 250, 500, 1000, 2000, 4000, 8000 ppm. Later, For measuring the cell vitality, MTT method was utilized .Measuring the photo absorption was done by ELISA READER system at 570 nm, which evaluated the vitality of cell by the value of MTT absorption cells. The statistical ANOVA test was used in this study. All of drug concentration were effective in Loweriy cellular biologic ectivity but none of them were statis fically significant. Therefore as a conclusion we can adjudicate that [Nano-HA] biomaterial is the material which is compatibility with the human blood mononuclear cells
ABSTRACT
Background and Aim: Antimicrobial effects of nano silver particles have received enormous attention in medical and dental applications. Despite of wide spread use of nanosilver there is not enough studies about its side effects on human. Some studies have exhibited cytotoxicity of nano-silver particles. This research was designed to investigate the cytotoxic effect of nano silver particles on L929 fibroblasts cells, by MTT assay
Materials and Methods: In this experimental study, nano silver particles with 5,10,20,30,40 and 50 ppm concentration were exposed to 10.000 L929 fibroblast cells then cell vitality was assessed after 2,24,48 and 72 hours by MTT method. The light absorption was evaluated by Elisa Reader and recorded. Data was subjected to ANOVA test for statistical analysis
Results: In all concentration groups, vitality of cells were the least after 24 hours, but the vitality of cells increased after 48 hours. The increase after 48H was statistically significant [p<0.05]. Also concentrations more than 20 ppm in 2,24 and 48 H were significantly cytotoxic for fibroblasts
Conclusion: Nano silver particles at concentrations less than 20 ppm after 72 hours did not have toxic effects
ABSTRACT
One of the asymptomatic lesions associated with an impacted mandibular third molar is localized periodontal pocket on the distal surface of mandibular second molar. In this study, relationship between periodontal pocket on the distal surface of mandibular second molars and pattern and depth of impaction is evaluated. The study was performed experimentally. A group of 100 patients, referring to surgical department of shahed dental school and shahid montazeri clinic [1386-87], were selected sequentially for the purpose. Pattern and depth of mandibular third molar impaction were recorded in studying form according to O.P.G radiograph. The impacted third molars were extracted by means of a clinical indication and depth of periodontal pocket was measured 4-24 months after surgical extraction. Statistical software of SPSS for windows was used for data analysis, using Kruskal-Wallis and Mann-Whitney tests for assessing relationship between periodontal pocket depth and pattern and depth of mandibular third molar impaction. The age of the patients was 24.S +/- 7, 55 individuals [55%] were females while the next 45 individuals [45%] were males. There was statistically significant difference between periodontal pocket depth and pattern and depth of mandibular third molar impaction. [p<0.001] Based on the findings of this study, deep periodontal pockets on the distal surface of a mandibular second molar, is mostly associated with horizontal, mesioangular and class C impacted third molar. So, more attention should be given to the detection of signs of periodontal pockets on the distal aspects of mandibular second molars when assessing the clinical state of the adjacent impacted third molars, because pattern and depth of impaction could be very determinative