azadeh esmaeil nejad

Statement of the Problem:

 Currently, the reconstruction of bone defects with new platelet concentrates is considered a significant challenge in periodontics.

This study aimed to evaluate advanced- platelet rich fibrin (A-PRF) and leukocyte- and platelet rich fibrin’s (L-PRF) effects on the proliferation and differentiation of MG-63 cells.

In this in vitro study, blood samples of five healthy non-smoking volunteers were collected and immediately centrifuged according to the two protocols of Choukroun and Ghanaati, without adding any anticoagulants, to prepare L-PRF and A-PRF. After freezing the clots for one hour, they were crushed and centrifuged once more. After culturing MG-63 cells, the effects of 20%, 10%, 1%, and 0.5% concentrations of A-PRF and L-PRF extracts on cell proliferation and mineralization were evaluated by methyl thiazolyl tetrazolium (MTT) assay and Alizarin Red staining, respectively.

Generally, survival and proliferation in the L-PRF group at both time intervals were higher than the A-PRF group and increased with increasing the extract concentration. However, in the A-PRF group, there were no significant differences between the different concentrations, and only the number of cells increased over time. After three days, in the study on mineralization, nodule formation was observed only in the positive control group (osteogenic). In seven days, mineralized nodules were formed in all groups with different concentrations of A-PRF, but not in any of the L-PRF groups.

According to the results, L-PRF increased proliferation, and A-PRF exerted a positive effect on the differentiation of MG-63 cells.

Aggregatibacter actinomycetemcomitans (Aa) plays a vital role in some destructive forms of periodontitis. While mechanical and chemical plaque control is the first step in periodontitis treatment, side effects of adjunctive chemical agents such as chlorhexidine (CHX) mouthwash have led to the application of natural alternatives with minimal side effects. Therefore, this study evaluated the antibacterial effect of the hydroalcoholic extract of Quercus infectoria (Qi) galls on Aa in vitro.

The hydroalcoholic extract of Qi was obtained by the maceration method, and Aa bacterial strain was cultured. The inhibition zone diameter was measured through the agar well diffusion method. Also, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined by the broth microdilution method. All the experiments were repeated three times. 0.2% CHX was used as a control.

The inhibition zone diameter of Aa increased with increasing concentration of Qi extract. While MIC and MBC values for CHX were 0.0039 and 0.0078 mg/mL, respectively, both MIC and MBC values of the Qi extract for this bacterium were similar, i.e., 2.5 mg/mL, which was significantly higherd.

Since other in vivo studies have confirmed the other properties of this extract and its safety in terms of cytotoxicity and mutagenicity, hydroalcoholic extract of Qi may be used in mouthwashes or local delivery systems to affect periodontal biofilm.

The enhancement of osteogenesis by tissue engineering is a challenge in periodontal therapy. Several graft materials in conjunction with carriers, such as blood or saline, are used for this purpose. This study aimed to assess the effect of phosphate buffered saline (PBS), Hank's balanced salt solution (HBSS) and saline on the activity of MG-63 osteoblast-like cells in the presence and absence of beta-tricalcium phosphate (β-TCP).

In this in vitro experimental study, MG-63 osteoblast-like cells were cultured in 10% PBS, HBSS and saline (10%) with and without β-TCP granules for 24 and 72 h and five days. At 24 and 72 h, cell viability and proliferation were assessed. Alkaline phosphatase (ALP) activity test was used to assess bone activity. The data were analyzed using SPSS version 20 (IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp) via one-way and two-way ANOVA (P<0.05).

Pairwise comparisons showed no significant difference in the viability of MG-63 cells at 24 h in the three solutions (with equal β-TCP content) or with the negative control group (complete culture). At 72 h, significant differences were only observed in the reduction of cell proliferation between 10% saline without β-TCP and 10% saline with β-TCP , and also between HBSS without β-TCP and HBSS with β-TCP (P<0.05).

The three solutions did not induce ALP activity at 24 or 72 h and did not cause the formation of any calcified nodule at three or five days in MG-63 cells.

 Zeolite is an aluminosilicate biomaterial which has been used widely in medicine, tissue engineering, drug delivery systems, wound dressing, as an antibacterial agent and also it has been taken into consideration in dental sciences. So the aim of this study is reviewing the application of this amazing substance in dental sciences.
Materials and 

In recent years there are many investigations on application of Zeolite. This review has been done on the application of this agent in dentistry. According to investigations from 1980, zeolites applications in dentistry were classified to the application in tissue engineering, root canal therapy, prosthodontics, periodontics and implant, restorative dentistry and oral medicine.

zeolite is a porous, biocompatible and antibacterial agent and according to its suitable properties it has been used as tissue engineering scaffold, wound dressing and so on. Zeolite is an antibacterial agent that can be used in root canal disinfection and in soft liner dentures. It can inhibit pathogens of dental caries and periodontal disease. According to biocompatibility of Zeolite, it also can be used as implant coating to improve osteointegration. It has also been used to detect squamous cell carcinoma.

It seems that Zeolite can be considered as an amazing substance in dental sciences.

 Atherosclerosis is known as one of the chronic diseases with high prevalence in the human species. Many studies have elucidated the relationship between this disease and chronic periodontitis caused by Porphyromonas gingivalis (P.g). The aim of this study was to investigate the prevalence of P.g fimbriae A (fimA) genotypes II and IV in patients with periodontitis and atherosclerosis.

This cross-sectional study investigated the frequency of P.g II and IV genotypes in the subgingival plaque specimens of 42 subjects in three experimental groups: periodontitis (A), atherosclerosis (B), periodontitis + atherosclerosis (C) and aortic wall specimens obtained from 30 patients (groups B and C) by the PCR technique.

P.g bacterium was seen in 46.6% of patients with chronic periodontitis. The same bacterium was not found in aortic wall specimens of patients with chronic periodontitis (group C) and there was only one P.g-positive aortic wall specimen (7.7%) among the patients with healthy periodontium (group B). Genotypes II and IV were not observed in any specimen.

The results of statistical analysis showed no significant correlation between the prevalence of P.g and genotypes II and IV in the subgingival plaques and the incidence and severity of atherosclerosis

The aim of this study was to evaluate the intra and inter-examiner reliability and reproducibility of linear measurements in cone-beam tomography (CBCT) images taken by calibrated radiologists and periodontists. The alveolar ridge dimensions in selected CBCT images were measured by two calibrated radiologists and two periodontists. Intra and inter-examiner reliability was evaluated by intra-rater and intra-class correlation coefficients (ICCs). ICCs between the intra-and inter-examiners obtained with the different methods showed almost perfect matches. The results demonstrated high examiner reproducibility for linear parameters of alveolar ridges in CBCT images in presurgical implant site assessment. The alveolar ridge dimensions provided by the radiologists might be useful for the periodontists. The measurement in small differences in is related to the experience and skills of the examiner, inclination measurement, selection of the exact level of the alveolar crest and the ability to detect the exact anatomic borders in CBCT images.