The comparison of the salivary concentration of interleukin-17 and interleukin-18 in patients with chronic periodontitis and healthy individuals.

BACKGROUND: Regarding the prevalence and importance of periodontal disease and the potential of salivary biomarkers for the early diagnosis of these diseases, this study was conducted to compare salivary concentrations of Interleukin-17 (IL-17) and Interleukin-18 (IL-18) in patients with chronic periodontitis and healthy individuals. MATERIALS AND METHODS: The present research was a descriptive-analytical and also a cross-sectional study. Unstimulated saliva with full-mouth clinical periodontal recordings were obtained from 20 healthy individuals and 20 individuals with chronic periodontitis. The concentrations of salivary IL-17 and IL-18 were determined using the enzyme-linked immunosorbent assays. The nonparametric Mann-Whitney U-test was used for statistical analysis of the findings. Alpha level was set at 0.05. RESULTS: The mean salivary concentration of IL-18 in patients with chronic periodontitis was 143.10 pg/mL, which was higher than the same concentration in healthy controls (78.33 pg/mL), (P = 0.035). The mean salivary concentration of IL-17 in patients with chronic periodontitis and healthy controls was 3.51 and 4.57 pg/mL, respectively, and there was no difference between the two groups (P = 0.283). CONCLUSION: Within the limitations of the present study, it may be suggested that an elevated salivary IL-18 level in chronic periodontitis patients has the potential to be a biomarker for periodontal tissue destruction.

Effects of Electrolyzed Water on the Growth of Oral Pathologic Bacteria Species and its Cytotoxic Effects on Fibroblast and Epithelial Cells at Different pH Values.

BACKGROUND: Microbial plaque-induced oral diseases are among the most common diseases worldwide. The present study aimed to compare the antimicrobial effect of electrolyzed water (EW), (acidic, mildly basic, and basic) on the growth of bacterial species producing dental plaque and to assess their cytotoxicity on fibroblasts and epithelial cells. METHODS: The study was performed at Shahid Beheshti University of Medical Sciences in 2019. Several bacterial species (Streptococcus salivarius, Staphylococcus aureus, Lactobacillus casei, and Aggregatibacter actinomycetemcomitans) were treated with different EW types at three pH values (3, 9, and 11) for 30 seconds and subsequently, the colonies were counted. The cytotoxic effect of these EW types was evaluated on HeLa and L929 cell lines at 30 seconds, 1 minute, and 5 minutes. GraphPad Prism 6.0 was used for statistical analysis. The Kruskal-Wallis test followed by Mann-Whitney U and one-way analysis of variance followed by Tukey's test were used to analyze bacterial activity and cell cytotoxicity, respectively. P<0.05 was considered statistically significant. RESULTS: EW types significantly inhibited bacterial growth at all pH values. The strongest antibacterial activity of EW was against A. actinomycetemcomitans (P<0.001) and the least significant antibacterial activity was against S. aureus (P<0.001). The EW types showed increased cytotoxic activity against L929 cells as the treatment time increased. The most cytotoxic effect was seen at 5 minutes of treatment in all EW types compared with the negative control group (P<0.0001). This negative cytotoxic effect on HeLa cells was shown just after 30 seconds and viable cell counts increased over time, reaching its highest value at 5 minutes of treatment with basic EW (P<0.0001). CONCLUSION: The contradictory effects of the EW types on both HeLa and fibroblasts, in addition to variable results at different exposure times, indicated that the effect of EW could vary depending on cell types and treatment periods.

Evaluating the adhesion of human gingival fibroblasts and MG-63 osteoblast-like cells to activated PRP-coated membranes.

Regeneration of periodontal tissues is affected by the biological and morphological characteristics of the membrane surface. The current study evaluated the adhesion of human gingival fibroblasts (HGF) and MG-63 osteoblast-like cells to Membranes, with and without activated PRP. The line of human gingival fibroblast cells and MG-63 osteoblast-like cells were first prepared and cultured on three types of membranes, including Jason, CenoMembrane and TXT-200 in three groups (FBS 10%, FBS 0.5% and activated PRP). Cell viability was investigated by MTT assay and electron microscopy (SEM) was used to evaluate the cell morphology and adhesion on these membranes after 24 and 72 h. Two-way ANOVA was carried out at the significance level of 0.05. The highest adhesion in the 10% FBS group for HGF and The MG-63 osteoblast-like cells was observed to the Jason membrane during 24 h and 72 h (p < 0.05). However, there were no significant differences among the three membranes in PRP and FBS groups for HGF during 24 h and for MG-63 cells during 72 h (p > 0.05). Activated PRP had a positive effect on the viability and adhesion of both human gingival fibroblasts and osteoblast-like cells as compared to the FBS 0.5% group, but these effects were not as 10% FBS group. The results also showed that Jason membrane had the highest amount of cell viability and adhesion.

In vitro Antibacterial Effect of Hydroalcoholic Extract of Lawsonia inermis, Malva sylvestris, and Boswellia serrata on Aggregatibacter actinomycetemcomitans.

BACKGROUND: Considering the increased rate of microbial resistance to antibiotics and chemical side effects of antibiotics and antiseptics used for the treatment of periodontal disease, there is a need for an alternative antimicrobial agent with fewer complications. Medicinal herbs have recently become popular as novel antimicrobial agents. This study aimed to assess the antibacterial effects of hydroalcoholic extracts of Lawsonia inermis, Malva sylvestris, and Boswellia serrata on Aggregatibacter actinomycetemcomitans. MATERIALS AND METHODS: Hydroalcoholic extracts of the three medicinal plants were obtained by the maceration technique and A. actinomycetemcomitans was cultured. Antimicrobial efficacy of the three medicinal plants was compared with that of 0.2% chlorhexidine (CHX) according to the Clinical and Laboratory Standards Institute protocol using agar disc diffusion and broth microdilution techniques. All tests were repeated three times. RESULTS: Hydroalcoholic extracts of all three plants had antimicrobial activity against A. actinomycetemcomitans. The minimum inhibitory concentration (MIC) of L. inermis, M. sylvestris, and B. serrata was 78.1, 156.2, and 1666 µg/mL with no significant difference between them. The MIC of CHX was 3.33 µg/mL, which was significantly higher than that of B. serrata extract. CONCLUSION: Given that further in vivo studies confirm other properties of these extracts and their safety in terms of cytotoxicity and mutagenicity, hydroalcoholic extracts of L. inermis and M. sylvestris may be used in mouthwashes or local delivery systems to affect periodontal biofilm.

Evaluation of inductive effects of different concentrations of cyclosporine A on MMP-1, MMP-2, MMP-3, TIMP-1, and TIMP-2 in fetal and adult human gingival fibroblasts.

Background The etiology of gingival overgrowth due to cyclosporine A (CsA) is still unknown. The aim of this study was to determine the possible role of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) on extra-cellular matrix (ECM) homeostasis when treated with different levels of CsA and its difference between fetal and adult human gingival fibroblasts (HGFs). Methods Each group of cells (adult and fetal) was cultured in 40 wells that consisted of four different CsA treatment concentrations. Every 10 wells were treated with 0, 50, 100, and 150 ng/mL of CsA which makes a total of 80 wells. Supernatants of every well were used to determine the concentration of MMPs and TIMPs using the Elisa kits from Boster, CA, USA. Results MMP-1 level increased with the treatment of CsA when treated with 50 and 150 ng/mL of CsA (p = 0.02 and p = 0.04) as TIMP-1 decreased (p < 0.0001) in adult group; while in the fetal group, TIMP-1 level increased with treatment of 150 ng/mL (p < 0.0001). MMP-2 level increased in both adult and fetal groups (p < 0.0001). MMP-3 level decreased in adult group (p < 0.0001) but went up in fetal HGFs (p = 0.01) when treated with 150 ng/mL CsA. TIMP-2 level increased in all wells significantly when treated with CsA (p < 0.0001). The study showed that CsA affects secretion of MMPs and TIMPs. MMP-1 increment and TIMP-1 decrement were observed, which indicate more degradation of ECM. This may be due to single donor use in this study. TIMP-2 and MMP-2 were both more active when treated with CsA which may be due to the gelatinase activity of them and that in CsA gingival overgrowth. There was more inflammation rather than fibrosis.

Association of vitamin D binding protein and vitamin D receptor gene polymorphisms in Iranian patients with chronic periodontitis.

Chronic periodontitis (CP) is a multifactorial disease and the most common type of periodontitis mainly caused by microbial plaque. Insufficient oral hygiene may initiate CP and it can be further modified and progressed by environmental and genetic susceptibilities. The aim of the present study was to investigate the association between VDBP (rs7041 and rs4588) and (Taq 1-rs7975232 and Apa1-rs731236) SNPs of VDR gene receptor and susceptibility to CP in an Iranian population. Sixty nine cases with diagnosis of CP and 78 matched healthy controls engaged in this study. Three-milliliter peripheral blood samples were obtained for DNA isolation. Genotype analysis was performed using restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). Chi-squared test was used for distribution of genotypes analysis. 95% confidence interval (CI) was used to calculate the odds ratio (OR). Deviation from Hardy-Weinberg equilibrium, multiple inheritance models, linkage disequilibrium and haplotype analysis were done. There was no significant association between genotype/phenotype of VDBP's SNPs (rs7041 and rs4588) and occurrence of chronic periodontitis (p value = 0.401) Moreover, no statistically significant association was found between chronic periodontitis and Taq1 (rs731236) (p value = 0.401) and Apa1 (rs7975232) (p value = 0.248). The analysis of alleles and genotypes' distribution between different severities of chronic periodontitis and healthy controls indicated a significant association between various severities of chronic periodontitis and Apa1 (rs7975232) (p value = 0.011) and VDBP's SNPs (rs7041 and rs4588) (p value = 0.038), whereas no statistically significant association was observed between various severities of chronic periodontitis and Taq1 (rs731236) (p value = 0.278). Our results suggest a significant association between severity of chronic periodontitis and Apa1 (rs7975232) and VDBP SNPs (rs7041 and rs4588). Sequencing studies on different populations may release other results due to the genetic and racial diversity.

Comparison of antimicrobial effect of Ziziphora tenuior, Dracocephalum moldavica, Ferula gummosa, and Prangos ferulacea essential oil with chlorhexidine on Enterococcus faecalis: An in vitro study.

BACKGROUND: Different irrigating solutions with high antimicrobial activity have been introduced for cleaning of the root canal system. However, effects of Prangos ferulacea (PF), Ziziphora tenuior (ZT), Dracocephalum moldavica (DM), and Ferula gummosa (FG) on oral and dental pathogens have not been extensively evaluated due to their optimal biocompatibility and insignificant side effects. The aim of this study was to evaluate the antibacterial effects of essential oils of mentioned plants on Enterococcus faecalis. MATERIALS AND METHODS: In this in vitro study the plants were collected from Zanjan Province, Iran. Analysis of the essential oil was carried out by gas chromatography/mass chromatography. Micro-broth dilution and disc diffusion methods were used for assessment of the antimicrobial activity, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. RESULTS: All the four essential oils had antibacterial effects on E. faecalis, and ZT had the greatest antibacterial activity. Assessment of the mean diameter of the growth inhibition zone showed higher antibacterial activity of PF and ZT than that of chlorhexidine. The MIC and MBC of ZT showed that the antimicrobial activity of ZT against E. faecalis was greater than that of other plants evaluated in this study. CONCLUSION: The results of this study indicated significant antibacterial effects of the mentioned plants on E. faecalis. The greatest antimicrobial activity belonged to ZT. The current study suggests extraction of effective compounds in these medicinal plants to use them in the clinical setting.

Interleukin-2, -16, and -17 gene polymorphisms in Iranian patients with chronic periodontitis.

AIM: Chronic periodontitis (CP) is a multifactorial disease and the most common type of periodontitis mainly caused by microbial plaque. CP can be brought on by, and progresses with, insufficient oral hygiene, and environmental and genetic susceptibilities. The aim of the present study was to investigate the association between interleukin (IL)-2 (T-330G), IL-16 (T-295C), and IL-17 (A-7383G) gene polymorphisms and the susceptibility to CP in an Iranian population. METHODS: Ninety-nine cases diagnosed with CP and 75 matched healthy controls engaged in the present study. 3 cc peripheral blood samples were obtained for DNA isolation. Genotype analysis was performed using restriction fragment length polymorphism polymerase chain reaction. Genotype distribution and allele frequencies within groups were compared using χ2 -test, and logistic regression analysis was used to recognize the independent relation between the disease and the absence or presence of alleles. RESULTS: There was no polymorphism in IL-2 (T-330G) among our patients, and the TT genotype was present in both study groups. Moreover, none of the studied genotypes and alleles of IL-16 (T-295C) and IL-17 (A-7383G) was significantly associated with CP. CONCLUSION: The present study demonstrated no association between IL-2 (T-330G), IL-16 (T-295C), and IL-17 (A-7383G) genotypes and CP in an Iranian population.

Correction to: Comparison of the effect of activated or non-activated PRP in various concentrations on osteoblast and fibroblast cell line proliferation.

In the original publication of this article, the affiliation of the corresponding author has been published incorrectly. Now the correct affiliation has been provided in this erratum.

Comparison of the effect of activated or non-activated PRP in various concentrations on osteoblast and fibroblast cell line proliferation.

Platelet-rich plasma (PRP) contains growth factors which positively affect cell proliferation, cell differentiation, chemotaxis and intracellular matrix synthesis. All these processes are involved in wound healing and tissue regeneration; thus, PRP as a source of growth factors can be used in periodontal regenerative therapies. The purpose of the present study was to assess the effect of various concentrations of activated and non-activated PRP on proliferation of osteoblasts and fibroblasts in vitro. PRP was obtained from three healthy volunteers. 75, 50, 25, and 10% concentrations of f PRP were prepared by dilution in Dulbecco's modified Eagle's medium. In activated PRP groups, PRP concentrations were activated by adding calcium gluconate. Human gingival fibroblast (HGF) cell line and MG-63 (osteosarcoma) human osteoblast-like cell line were used in the study. The MTT proliferation assay was used to assess the effect of different types of PRP concentrates on proliferation of HGF and MG-63 cells, in 24, 48 and 72 h. After 24, 48, and 72 h, the proliferation rate of both cell lines was higher in the positive control group, except in 72 h in HGF cell lines, that 10% non-activated PRP group and 10 and 25% activated PRP groups has higher proliferation rate than the positive control group, which it was not significant. Proliferation rate in cells with 10% activated PRP was highest among samples containing PRP. The current study failed to show the significant effect of activated or non-activated PRP on proliferation of HGFs or MG-63 osteoblast-like cells. However, our results showed that activated PRP had a greater effect than non-activated PRP.

In vitro comparison of the efficacy of TGF-ß1 and PDGF-BB in combination with freeze-dried bone allografts for induction of osteogenic differentiation in MG-63 osteoblast-like cells.

Predictable regeneration of alveolar bone defects has always been a challenge in implant dentistry. Bone allografts are widely used bone substitutes with controversial osteoinductive activity. This in vitro study aimed to assess the osteogenic potential of some commercially available freeze-dried bone allografts supplemented with human recombinant platelet-derived growth factor-BB and transforming growth factor beta-1. Cell viability, mineralization, and osteogenic gene expression of MG-63 osteoblast-like cells were compared among the allograft alone, allograft/platelet-derived growth factor-BB, allograft/transforming growth factor beta-1, and allograft/platelet-derived growth factor-BB/transforming growth factor beta-1 groups. The methyl thiazol tetrazolium assay, real-time quantitative reverse transcription polymerase chain reaction and alizarin red staining were performed, respectively, for assessment of cell viability, differentiation, and mineralization at 24-72 h post treatment. The allograft with greater cytotoxic effect on MG-63 cells caused the lowest differentiation among the groups. In comparison with allograft alone, allograft/transforming growth factor beta-1, and allograft/transforming growth factor beta-1/platelet-derived growth factor-BB caused significant upregulation of bone sialoprotein and osteocalcin osteogenic mid-late marker genes, and resulted in significantly higher amounts of calcified nodules especially in mineralized non-cytotoxic allograft group. Supplementation of platelet-derived growth factor-BB alone in 5 ng/mL concentration had no significant effect on differentiation or mineralization markers. According to the results, transforming growth factor beta-1 acts synergistically with bone allografts to enhance the osteogenic differentiation potential. Therefore, this combination may be useful for rapid transformation of undifferentiated cells into bone-forming cells for bone regeneration. However, platelet-derived growth factor-BB supplementation did not support this synergistic ability to enhance osteogenic differentiation and thus, further investigations are required.

Correlation of interleukin-6-174 GC and interleukin-6-572 GC gene polymorphisms with periodontal disease in an Iranian population.

BACKGROUND: Periodontal disease has a multifactorial etiology. A combination of microbial agents and environmental, habitual, systemic, and genetic risk factors is responsible for the development of periodontal disease. Host immune response causes the destruction of tooth-supporting structure and eventual tooth loss. This study aimed to assess the correlation of interleukin 6 (IL-6) -174-GC and IL-6-572-GC gene polymorphisms with periodontal disease in an Iranian population. MATERIALS AND METHODS: This case-control analytical study was conducted on 129 subjects presenting to the laboratory of Taleghani Hospital. Subjects underwent clinical and periodontal examinations and divided into five groups of healthy, gingivitis and mild, moderate and severe periodontitis. Blood samples (2 ml) were obtained. Genomic DNA was extracted manually using the salting-out method. IL-6 sequence amplification was performed using polymerase chain reaction with three thermal protocols. Digested products were analyzed by electrophoresis through 2% agarose gel using Gel Red staining. Data were analyzed using Chi-square, Kruskal-Wallis, and Mann-Whitney tests, and P < 0.05 was considered significant. RESULTS: The frequency of GG polymorphism at IL-6-174 and IL-6-572 genomic regions was 51.2% and 71.3%, respectively. The frequency of IL-6-572-GG polymorphism was significantly greater than that of IL-6-572-GC polymorphism (P < 0.001). Comparison of the mean and maximum pocket depth and clinical attachment level, as well as bleeding on probing percentage, revealed significant differences between the healthy controls and periodontitis patients (P < 0.001). The frequency percentages of GC and GG polymorphisms were almost equal in the healthy, gingivitis, and periodontitis groups. In other words, the frequency of the two polymorphisms was not significantly different between the health and disease states (P = 0.065 for IL-6-572 and P = 0.63 for IL-6-174). CONCLUSION: This study found no association between IL-6-174 and IL-6-572 gene polymorphisms and periodontitis in the studied population.

Osteoinductive Activity of DFDBA Materials versus Growth Factors on Gene Expression of MG-63 Cells: An In Vitro Study.

Guided bone regeneration using demineralized freeze-dried bone allograft (DFDBA) and growth factors (GFs) is a current goal in implant dentistry because of their potential osteoinductive abilities. Regarding controversial results, the purpose of this study was to compare the osteoinductivity of three different DFDBAs from two different banks with two different GFs: transforming growth factor-beta (TGF-ß) and platelet-derived growth factor (PDGF). MG-63 osteoblast-like cells were exposed to two different concentration of commercial DFDBAs (10 and 20 mg/mL) and growth factors (5 and 10 ng/mL). Cell viability and proliferation were evaluated using a quantitative MTT assay (24 and 72 hours after treatment). For the assessment of cell differentiation, the expression of osteogenic marker genes was evaluated using quantitative real-time polymerase chain reaction 72 hours after treatment. Cell viability and proliferation in different concentrations of GFs was similar but significantly different in the DFDBA groups. Although water-soluble materials released from DFDBAs reduced viability and even caused cytotoxicity (viability <70%) in first 24 hours after treatment, increased viability and proliferation were seen after 72 hours. Dose-dependent up-regulation of osteocalcin (OC) was seen in the two DFDBA groups and in TGF-ß-treated cells. In contrast, dose-dependent down-regulation of OC was seen in PDGF-treated cells. The results show that induction of osteogenic differentiation (osteoinduction) at higher concentrations of DFDBAs (with the exception of one group) is more rapid than in the GF groups. In addition, TGF-ß at higher concentrations but PDGF at lower concentrations were associated with better results.

In vitro effect of mineralized and demineralized bone allografts on proliferation and differentiation of MG-63 osteoblast-like cells.

Due to the extensive use of bone allografts in bone reconstruction and periodontal therapy as suitable alternatives to autografts, they are now marketed under different commercial brands. Considering the controversial reports regarding the osteoinductive properties of bone allografts, this study sought to assess the effect of type (mineralized/demineralized), amount and particle size of several allografts on the proliferation and differentiation of MG-63 osteoblast-like cells. MG-63 cells (24-h culture) were exposed to 20 and 40 mg amounts of nine different commercially available freeze-dried bone allografts. After 24 and 72 h of incubation, the effect of water-soluble allograft released materials on cell viability and proliferation was assessed using methyl thiazol tetrazolium (MTT) assay after 24 and 72 h of exposure. Cell differentiation and mineralization was assessed by real-time quantitative reverse transcription PCR and alizarin red staining after 72 h of exposure. The amount and particle size of understudy allografts had significant effects on cell viability after 24 h of exposure (in contrast to 72 h). Higher rate of proliferation was seen in non-differentiated or slow-differentiated groups. The amount and particle size factors had no significant effect on the amount of calcified nodules or the expression of osteogenic marker genes in most groups. Faster and more distinct differentiation and mineralization was noted in mineralized compared to demineralized groups during the 3-day study period. Based on the results, the understudy mineralized (non-demineralized) bone allografts had greater effect on osteogenic differentiation of the MG-63 cells and showed more in vitro osteoinductive activity compared to partially demineralized and fully demineralized types.

Characteristics and relationship of periodontal disease with juvenile idiopathic and rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is the most prevalent chronic inflammatory disease of the joints. It is correlated with periodontal disease due to similar factors that exist in both diseases. The present study assessed the relationship of periodontal disease with RA and juvenile idiopathic arthritis (JIA). MATERIALS AND METHODS: In this case-control study, 30 RA and 30 JIA patients along with similar number of matched controls were selected among patients referred to Imam Khomeini Hospital, Tehran, Iran. Periodontal parameters including pocket depth (PD), clinical attachment level (CAL), O'Leary and Bay plaque index (PI) and bleeding on probing (BOP) were determined in cases and controls. Erythrocyte sedimentation rate, number of painful and inflamed joints and severity of disease were evaluated in RA and JIA patients. Mann-Whitney U-test nonparametric, Spearman and Pearson's correlation coefficients, and Chi-square tests were used as statistical analysis (α = 0.05). RESULTS: PD (4.17 vs. 3.6 mm; P < 0.0001), CAL (4.89 vs. 4.18 mm; P < 0.002), percentage of sites with PD >4 mm (58.83% vs. 44.33%; P < 0.002), percentage of sites with CAL >3 mm (74.13% vs. 64.4%; P < 0.001), percentage of sites with BOP (9.67% vs. 6.87%; P < 0.0001) and PI index (85.73% vs. 80.63%; P < 0.0001) were significantly higher in RA patients than controls. In this group, direct and significant correlations were found between serologic findings, disease severity and number of painful and inflamed joints with periodontal factors. In JIA patients, no significant relationships were found between JIA findings and periodontal parameters. CONCLUSION: Considering the limitations of this study, there was a relationship between RA and periodontal disease. Severity of periodontal disease increases in patients with RA, while no increased risk of periodontal disease or its severity was observed among JIA patients.

Effects of Plasma Rich in Growth Factors and Platelet-Rich Fibrin on Proliferation and Viability of Human Gingival Fibroblasts.

OBJECTIVES: Platelet preparations are commonly used to enhance bone and soft tissue regeneration. Considering the existing controversies on the efficacy of platelet products for tissue regeneration, more in vitro studies are required. The aim of the present study was to compare the in vitro effects of plasma rich in growth factors (PRGF) and platelet-rich fibrin (PRF) on proliferation and viability of human gingival fibroblasts (HGFs). MATERIALS AND METHODS: Anitua's PRGF and Choukran's PRF were prepared according to the standard protocols. After culture periods of 24, 48 and 72 hours, proliferation of HGFs was evaluated by the methyl thiazol tetrazolium assay. Statistical analysis was performed using one-way ANOVA followed by Tukey-Kramer's multiple comparisons and P-values<0.05 were considered statistically significant. RESULTS: PRGF treatment induced statistically significant (P<0.001) proliferation of HGF cells compared to the negative control (100% viability) at 24, 48 and 72 hours in values of 123%±2.25%, 102%±2.8% and 101%±3.92%, respectively. The PRF membrane treatment of HGF cells had a statistically significant effect on cell proliferation (21%±1.73%, P<0.001) at 24 hours compared to the negative control. However, at 48 and 72 hours after treatment, PRF had a negative effect on HGF cell proliferation and caused 38% and 60% decrease in viability and proliferation compared to the negative control, respectively. The HGF cell proliferation was significantly higher in PRGF than in PRF group (P< 0.001). CONCLUSION: This study demonstrated that PRGF had a strong stimulatory effect on HGF cell viability and proliferation compared to PRF.

Effect of phenytoin and age on gingival fibroblast enzymes.

OBJECTIVE: The alteration of cytokine balance is stated to exert greater influence on gingival overgrowth compared to the direct effect of the drug on the regulation of extracellular matrix metabolism. The current study evaluated the effect of phenytoin on the regulation of collagen, lysyl oxidase and elastin in gingival fibroblasts. MATERIALS AND METHODS: Normal human gingival fibroblasts (HGFs) were obtained from 4 healthy children and 4 adults. Samples were cultured with phenytoin. MTT test was used to evaluate the proliferation and ELISA was performed to determine the level of IL1ß and PGE2 production by HGFs. Total RNA of gingival fibroblasts was extracted and RT-PCR was performed on samples. Mann-Whitney U test was used to analyze the data with an alpha error level less than 0.05. RESULTS: There was a significant difference in the expression of elastin between the controls and treated samples in both adult and pediatric groups and also in the lysyl oxidase expression of adult controls and treated adults. No significant difference was found between collagen expression in adults. CONCLUSION: The significant difference in elastin and lysyl oxidase expression between adult and pediatric samples indicates the significant effect of age on their production.

Effects of cyclosporine and phenytoin on biomarker expressions in gingival fibroblasts of children and adults: an in vitro study.

BACKGROUND: Both phenytoin (PhT) and cyclosporine (CsA) have been related to gingival overgrowth, but the presence and incidence of cytokines in gingival tissues are associated with different mechanisms. On the basis of a few epidemiologic data, children are more prone to have gingival overgrowth than adults and there is no obvious plausibility to justify this difference. The aim of this study was to investigate the effect of PhT and CsA on the some biological marker expression and compare it among adults and children. METHODS: Gingival fibroblasts that had been harvested from adults and children with normal gingiva were incubated with CsA and PhT and then cultured for 48 h. Matrix metalloproteinases (MMP-1 and MMP-2), tissue inhibitor of metalloproteinases (TIMP), collagen (CoL), elastin (Eln), lysyl oxidase (Lysyl), cathepsin (Cat) L and B, and mRNA levels in culture were determined by reverse transcription polymerase chain reaction. The amounts of transforming growth factor-ß (TGF-ß) and epidermal growth factor (EGF) were assessed by enzyme-linked immunosorbent assay. RESULTS: CsA and PhT stimulated TGF-ß and Cat B production and inhibited expression of MMP-1 by fibroblasts. CsA suppressed TIMP in children, but PhT stimulated its expression. In adults, both CSA and PHT increased TGF-ß, Lysyl, and EGF levels. CsA reduced Eln level, whereas PhT increased it. CONCLUSIONS: The results suggest that CsA and PhT have different effects on biogene marker expression in adults and children, or drug-induced gingival overgrowth is affected by different cellular pathways in children in contrast to that in adults. It seems that in children the MMP-1/TIMP system, and in adults the Lysyl/Eln pathway, plays an important role in impaired CoL metabolism.

Proliferative and inductive effects of Cyclosporine a on gingival fibroblast of child and adult.

BACKGROUND: Gingival overgrowth is a serious side-effect that accompanies the use of Cyclosporin A (CsA). Up to 97% of the transplant recipient children, who were submitted to CsA therapy, have been reported to suffer from this side-effect. Several conflicting theories have been proposed to explain the fibroblast's function in CsA-induced gingival overgrowth. The aim of this study is to assess the proliferation of gingival fibroblasts and levels of released cytokines after being exposed to CsA, in both adults and pediatric groups, and to make a comparison between the results of the two groups. MATERIALS AND METHODS: The adult fibroblast samples were derived from four healthy adults, aged 35 to 42 years and pediatric samples were obtained from four healthy children, age between four and eleven years. Tissue samples were plated in Dulbecco's Modified Eagle Medium (DMEM) containing 10% fetal bovine serum (FBS), Streptomycin and Penicillin. The samples were cultured in 25 cm(2) plates containing 5% CO2, and incubated at 37°C. The cells used for all the experiments were at the fourth passage. The concentration of PGE2, IL-1ß, IL-6, IL-8, TNF-α, and TGF-ß1 was determined by the enzyme-linked immunosorbent assay (ELISA) and the proliferation rate was assessed by the MTT assay. Alpha error levels were set as 0.05. RESULTS: CsA stimulated significantly higher levels of IL-6, IL-8 and TGF-ß1 in adult gingival fibroblasts than it did in the control group; whereas, the expression of IL-1ß and PGE2 in the fibroblasts exposed to CsA was significantly weaker (P < 0.05). The fibroblasts in the two groups did not reveal any noticeable difference in the production of TNF-α. Furthermore, cell proliferation in the CsA group was not significantly higher than that in the control group. No significant differences in cytokines TNF-α and IL-1ß were noted between the two groups. The results indicated that CsA stimulated cell proliferation in the pediatric fibroblast cell line. Comparison between the results in the adult and pediatric groups demonstrated that the levels of IL-1ß, IL-6, IL-8, and PGE2 were significantly higher in the pediatric group than in the adult group; however, statistics showed no significant difference in the levels of TNF-α and TGF-ß1 and CsA-induced proliferation between these two groups. CONCLUSIONS: The mechanism of a CsA-induced fibroblast overgrowth may converge on the steps involving fibroblast proliferation and cytokine network including IL-6, IL-8, IL-1ß, TGF-ß1, and PGE2, in both adults and pediatrics. As the prevalence and intensity of drug-induced gingival overgrowth is more serious in the pediatrics. As group than in adults, we suggest that more studies be conducted on the pediatric group.

Atomic force microscopy application in biological research: a review study.

Atomic force microscopy (AFM) is a three-dimensional topographic technique with a high atomic resolution to measure surface roughness. AFM is a kind of scanning probe microscope, and its near-field technique is based on the interaction between a sharp tip and the atoms of the sample surface. There are several methods and many ways to modify the tip of the AFM to investigate surface properties, including measuring friction, adhesion forces and viscoelastic properties as well as determining the Young modulus and imaging magnetic or electrostatic properties. The AFM technique can analyze any kind of samples such as polymers, adsorbed molecules, films or fibers, and powders in the air whether in a controlled atmosphere or in a liquid medium. In the past decade, the AFM has emerged as a powerful tool to obtain the nanostructural details and biomechanical properties of biological samples, including biomolecules and cells. The AFM applications, techniques, and -in particular- its ability to measure forces, are not still familiar to most clinicians. This paper reviews the literature on the main principles of the AFM modality and highlights the advantages of this technique in biology, medicine, and- especially- dentistry. This literature review was performed through E-resources, including Science Direct, PubMed, Blackwell Synergy, Embase, Elsevier, and Scholar Google for the references published between 1985 and 2010.