Lymphangiogenesis in Odontogenic Keratocysts Compared with Dentigerous Cysts.

Statment of the Problem: Podoplanin can indicate the lymphangiogenesis. On the other hand, lymphangiogenesis affects the biological behavior of lesions. The clinical behavior of odontogenic keratocysts (OKC) and dentigerous cysts (DC) is different. Purpose: This study aimed to evaluate the immunohistochemical expression of podoplanin and to investigate lymphangiogenesis in OKCs as compared to DCs. Materials and Method: In this experimental laboratory study, sixty paraffined blocks, including 30 OKC and 30 DC samples, were examined in this study, all of which were histopathologically non-inflamed. To evaluate lymphangiogenesis, the immunohistochemical reaction of D2-40 was evaluated via cytoplasmic and membrane staining of lymphatic endothelial cells. The expression of podoplanin in the epithelial cells of two cyst groups was also examined. To analyze the collected data and compare the results between the two groups of cysts, independent samples t-test, Mann-Whitney U test, and Chi-square test were performed in SPSS version 22. The significance level was set at 0.05. Results: The mean lymph node count and podoplanin expression were significantly higher in the OKC epithelium as compared to DC (p< 0.001). Based on the results, 90% of OKC samples and 43.3% of DC samples showed grade 3 staining. Conclusion: The rate of lymphangiogenesis and podoplanin expression in the epithelium were higher in OKCs compared to DCs. According to the results, the expression of podoplanin may be a useful marker for determining the invasiveness and proliferation of OKC.

Genotoxic and Cytotoxic Effects of Cone Beam Computed Tomography and Multidetector Computed Tomography on Exfoliated Buccal Epithelial Cells.

Background: Cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) are frequently used in dental and maxillofacial problems. This study aimed to assess the genotoxicity and cytotoxicity effects of CBCT and MDCT radiographies on exfoliated buccal epithelial cells during dental examinations. Methods: This prospective experimental study was conducted at Babol University of Medical Sciences (Babol, Iran) from March 2021 to April 2021. Buccal mucosa smears were collected bilaterally pre-exposure and 12 days after CBCT or MDCT examinations. To compare the frequency of micronuclei and other cytotoxic cellular changes such as pyknosis, karyolysis, and karyorrhexis, the paired sample t test and Wilcoxon test were used. In addition, independent sample t test, Mann-Whitney, and Chi square tests were used to investigate the differences between the imaging methods and between men and women. All statistical analyses were performed using the SPSS software, and P≤0.05 was considered statistically significant. Results: The current study included 60 adult patients (30 patients in each group), ranging in age from 21 to 50 years. The micronuclei and the other cytotoxic cellular changes increased significantly after CBCT and MDCT radiographic examinations on the 12th day compared to the pre-exposure results (P<0.001). MDCT had statistically higher cytotoxic and genotoxic effects than CBCT (9.4%, 23.1%, and 40% higher values in micronucleus frequency, the mean frequency of micronuclei, and other cytotoxic changes, respectively). There were no significant differences between men and women in the two examination methods (P=0.46 and P=0.49, respectively). Conclusion: Dental examinations with CBCT and MDCT can increase cytotoxicity and chromosomal damage in both men and women. Due to its lower radiation toxicities, CBCT can be recommended as an alternative to MDCT for dental examinations.

The effect of eliminating sintering during the synthesis of 3D scaffolds using the gel-casting method on their biological characteristics:in vivoandin vitroevaluations.

The possibility of making shapeable three-dimensional scaffolds along with suitable mechanical properties is one of the most challenging points in tissue engineering. This study investigated the effect of the eliminating sintering during the synthesis of Hydroxyapatite/Agarose nanocomposite foam produced by gel-casting method, as bone tissue cellular scaffold, on its biological characteristics. The Hydroxyapatite/Agarose nanocomposite foam was synthesized by gel-casting, and samples were divided into two groups: group S, in which half of the samples were sintered, and group C, which the other half of the samples were left unsintered. To assessin vitrocytotoxicity, the supernatant culture medium was extracted from 100 mg ml-1foam suspension in complete culture medium after 72 h incubation and diluted into various concentrations. SaOs-II cells were incubated with extracts of each scaffold at different concentrations and analyzed using the MTT assay. Additionally,in vivocharacteristics were evaluated by implanting the scaffolds in rat tibia. Overall, the number of living cells was higher in group S than in group C, except for concentrations of 25% and 75% after 24 and 48 h of incubation, respectively. MTT assay results indicated that concentrations below 50% for group S and 25% for group C could be considered non-toxic. Allin vivovariables exhibited significant changes over time, with most changes occurring faster in group S than in group C. There was a statistically significant difference between the two groups in terms of inflammation rate, osteocyte, osteoblast, and osteoclast count, as well as remaining biomaterial percentage only on day 30. Despite the delay in the tissue regeneration process observed by eliminating sintering during the gel-casting method, it is recommended as a means of producing reversible polymeric scaffolds with proper handling, cutting, and shaping capabilities that can be easily applied by clinicians during surgery according to the specific defect site.

Clinical, histological, and histomorphometrical comparison of CenoBone® with and without plasma rich in growth factor for edentulous ridge preservation in the dental sockets.

Background: The aim of this study was to compare the clinical, histological, and histomorphometrical outcomes of CenoBone® allograft with and without plasma rich in growth factor (PRGF) for the preservation of edentulous ridge in the dental sockets. Materials and Methods: This study is experimental clinical trial that 14 dental sockets were included the sockets required ridge preservation followed by implant placement in the premolar and molar of the mandible. After extraction of the teeth, the CenoBone® allograft and PRGF were used in the test group and CenoBone® allograft was used alone in the control group. During the first stage of surgery and 5 months later, in the second stage of surgery (implant placement), the vertical changes of the ridge were measured. Furthermore, using Core-Biopsy in the second stage of surgery, criteria of histologic and histomorphometric were determined. Data were analyzed with t-test, Mann-Whitney U-test, and Fisher's exact test at the level of significance of P < 0.05. Results: The mean trabecular thickness in the test group (52.18 ± 5.53) was significantly higher than that in the control group (41.53 ± 10.40) (P = 0.344). However, there were no significant differences in the mean values of vertical bone absorption, bone percentage, remaining biomaterials, inflammation, and blood vessels between the two groups. There was no case of foreign body reaction and the bone was vital in all the cases and in direct contact with the biomaterial. Conclusion: Although CenoBone® allograft with PRGF was effective in some histomorphometric factors such as trabecular thickness, it did not lead to significant clinical changes.

Genotoxicity and cytotoxicity effects of x-rays on the oral mucosa epithelium at different fields of view: A cone beam computed tomography technique.

Background: Cone beam computed tomography (CBCT) is considered a common examination for dentistry problems. Cellular biology can be affected by exposure to ionizing radiations procedures. In this study, we aimed to assess the genotoxicity and cytotoxicity effects of CBCT dental examinations at two different fields of view (FOVs) in exfoliated buccal epithelial cells. Methods: Sixty healthy adults participated in the current study. They were divided into two identical groups; CBCT with FOV of 6*6 cm2 and 8*11 cm2. Exfoliated oral mucosa cells were prepared immediately before and after 10-12 days of CBCT exposure. The cytological smears were stained with the Papanicolaou technique. The amounts of micronuclei and other cytotoxicity cellular changes (Pyknosis, Karyolysis, and Karyorrhexis) were evaluated. The variables of the parameters before and after CBCT examination in the two investigated FOVs were performed using Wilcoxon test and paired-samples t-test in SPSS software. Results: The micronuclei and other cytotoxic changes parameters before and after CBCT exposure for both FOVs (6*6 and 8*11 cm2) increased significantly (p<0.001). Furthermore, a significant difference (p<0.05) was observed between the investigated parameters at the two FOVs. Notably, the FOV of 8*11 cm2 had more side effects than that of 6*6 cm2. There were no statistically significant among males and females for both FOVs. Conclusion: CBCT examinations of dental disorders would increase the risks of inducing genetic damage. The cytotoxicity and chromosomal damage were considered in males and females in both investigated FOVs (6*6 and 8*11 cm2). In this regard, the use of CBCT must be following the ALARA principle.

Optimization of Fluorapatite/Bioactive Glass Nanocomposite Foams as Bone Tissue Scaffold: An in Vivo Study.

The present study investigated the suitability of nanocomposite foams of fluorapatite and bioactive glass (FA /BG) in different weight ratios as scaffolds for bone tissue in rat tibia regeneration to determine the optimal composition. FA and BG nano powders with a weight ratio of 25% FA/75% BG (compound 1) and 75% FA/25% BG (compound 2) were used as precursors for gel casting to produce nanocomposite foams. Thirty rats were randomly divided into two equal groups. Disk-shaped samples of each compound were implanted into the tibias of 15 rats. After 15, 30, or 60 days, five rats from each group were sacrificed and subjected to radiological, histopathological, and histomorphometrical examination. Data were analyzed using SPSS software. No foreign body reaction was observed in either group at all intervals, and the bone-biomaterial junction was direct. Overall, the inflammation rate, and the number of blood vessels, osteoblasts, and osteoclasts decreased over time in both groups. However, the number of osteocytes, trabecular bone thickness, and the percentage of new bone formation increased, in contrast to the remaining biomaterial percentage. Most of the changes in the group implanted with compound 2 were significantly more significant and faster than in the other group. Although the composite with the higher percentage of FA was superior to the composite with the higher percentage of BG, considering the results of our previous similar studies, the composite with the same percentage of FA and BG is more favorable to be used as a substitute for bone tissue in the body.

Anti-Cancer Effect of Bromelain and Its Combination with Cisplatin on HN5 Cell Line (Squamous Cell Carcinoma).

Statement of the Problem: Squamous cell carcinoma (SCC) comprises over 90% of oral malignancies. Cisplatin, as a selective chemotherapy agent to treat SCC, has many side effects despite its high effectiveness. There are some studies on the effects of bromelain derived from pineapple stems on different malignancies. Purpose: The aim of this study was to investigate the effect of bromelain alone and in combination with Cisplatin on oral squamous cell carcinoma (OSCC) and fibroblast cell lines. Materials and Method: In this interventional study, the HN5 cell line of OSCC and fibroblast cell line were treated with different concentrations of bromelain alone and in combination with cisplatin. Cell viability test was performed after 24, 48 and 72 hours using MTT (3-)4,5-dimethylthiazol-2-yl(-2,5 diphenyl tetrazolium bromide) assay. In the final stage, the drug-treated cells underwent flow cytometry to assess apoptosis patterns. Data were analyzed using SPSS 17, ANOVA (for general comparison of groups) and LSD post hoc tests (for comparison two groups). p< 0.05 was considered statistically significant. Results: The findings suggested that although bromelain showed toxic effects on HN5 cancer cells, its combination with Cisplatin resulted in little improvement in its effectiveness. Bromelain alone and in combination with Cisplatin presented cytotoxic effects against fibroblasts, which depended on the dosage and time exposure (p< 0.05). The flow cytometry results did not support the superior effect of the combination of two medications over Cisplatin alone (p> 0.05). Conclusion: According to the findings, although adding bromelain to Cisplatin reduced toxicity on normal tissues, the combination of these two drugs did not increase the anticancer effect of Cisplatin. Thus, bromelain in combination with Cisplatin is not recommended as an adjuvant drug for OSCC.

Prevalence of Co-infection by Human Papillomavirus, Epstein- Barr Virus and Merkel Cell Polyomavirus in Iranian Oral Cavity Cancer and Pre-malignant Lesions.

Human papillomavirus (HPV) is recognized as the most important risk factor in oral cavity cancer and pre-malignant lesions; however, the etiological association of concomitant infection with other oncogenic viruses as a co-factor has not been definitively proven. The present study aimed to determine the prevalence of co-infection with HPV, Epstein-Barr virus (EBV) and Merkel Cell PolyomaVirus (MCPyV) in oral cavity lesions in Iranian patients. One hundred and fourteen oral cavity samples, including 33 oral squamous cell carcinoma, 28 oral lichen planus, 16 oral epithelial dysplasia and 37 oral irritation fibromas were analyzed for the HPV, EBV and MCPyV infection by quantitative real-time PCR. According to histological features 32.5% and 28.9% of cases were oral irritation fibroma and oral squamous cell carcinoma, respectively. Infection with at least two viruses was detected in 21.1% of patients. In this group, co-infection with HPV/EBV was identified in 37.5% of cases, HPV/MCPyV in 29.2%, EBV/MCPyV in 12.5%, and HPV/EBV/MCPyV in 20.8%. There was no statistically significant difference between multiple infections and anatomical locations of cancer. The prevalence of triple viral infection (HPV/EBV/MCPyV) in well differentiated tumors was higher than EBV or MCPyV single infection. This study revealed that co-infection of HPV, EBV and MCPyV can be detected in both malignant and non-malignant oral cavity tissues, and co-infection with all three viruses in well differentiated tumors can be shown as a synergistic hypothesis of the pathogenic role of these viruses in oral malignant transformation.

Evaluation of apoptotic effect of crocin, cisplatin, and their combination in human oral squamous cell carcinoma cell line HN5.

BACKGROUND: Squamous cell carcinoma (SCC) is the most common oral malignancy with high rate of mortality. Cisplatin, as the most effective chemotherapy drug, has side effects. Considering the studies on the use of crocin in saffron in the treatment of various malignancies, this study aimed at investigating the effects of crocin and cisplatin and their combination on SCC and fibroblast cell lines. MATERIALS AND METHODS: In this interventional study, HN5 and fibroblast cell lines were treated with different concentrations of crocin (12.5-50 µg/mL) and cisplatin (2, 4, 8, 16, and 32 µg/mL), and the cells were counted after 24, 48, and 72 h by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Data were analyzed with SPSS Version 17, and P < 0.05 was considered the level of significance. In the final stage, flow cytometry after 24 h in terms of the pattern of cell death was done. RESULTS: Both drugs had a toxic effect on malignant cells. One point was the high toxic effect of 8 µg/mL cisplatin not only on cancer cells (P < 0.001) but also on fibroblasts. However, combination with 12.5 µg/mL of crocin had the same effect on HN5 cell line, despite the less toxic effect in fibroblasts in comparison with cisplatin alone (P = 0.012). Apoptosis was the pattern of cell death showed by flow cytometry. CONCLUSION: Crocin in high concentrations can have not only significant toxicity in cancer cells but also side effects in healthy tissue. It seems that lower doses of crocin, in combination with cisplatin, besides having anticancer effect, can reduce the toxicity of cisplatin in healthy tissue.

Oral mucosa and Streptococcus mutans count in the saliva. Does graphene oxide nanoparticle mouthwash have a good effect?

BACKGROUND: This study aimed to assess the effect of graphene oxide (GO) nanoparticles mouthwash on oral mucosa, Streptococcus mutans (S. mutans) count in the saliva of rats, and human enamel surface microhardness, in comparison with fluoride mouthwash. METHODS: This study was conducted in two phases namely an animal study, and an in vitro experimental study. GO mouthwash (0.005%), sodium fluoride (NaF) mouthwash (0.05%), and a combination of both (0.05% NaF-0.005% GO) were prepared. The oral cavity of 36 rats was inoculated with S. mutans, and they were randomly divided into 4 groups according to the type of mouthwash. The control group received saline mouthwash. Fourteen days after using the mouthwashes, all rats were sacrificed, and the salivary S. mutans count was measured. The buccal and tongue mucosa were also histologically examined for the type and severity of inflammation, number of blood vessels, epithelial thickness, and epithelial keratinization. For microhardness testing, 40 sound extracted human premolars were randomly assigned to four groups (n=10) of culture medium with S. mutans and different mouthwashes. The enamel microhardness was measured at 7 and 14 days, and compared with the baseline value. RESULTS: The mean S. mutans count in the saliva of rats in GO and NaF-GO groups was significantly lower than that in other groups (p<0.001). Enamel microhardness in NaF and NaF-GO groups significantly increased at 7 and 14 days, compared with baseline. CONCLUSION: Addition of GO nanoparticles improved the antibacterial properties without causing adverse mucosal effects such as ulceration, acute inflammation or atrophy of the epithelium of the oral mucosa, but had no effect on surface hardness of the enamel.

Angiogenesis and Lymphangiogenesis in Salivary Gland Adenoid Cystic Carcinoma and Mucoepidermoid Carcinoma.

BACKGROUND AND PURPOSE: This study aimed to investigate the immunohistochemical expression of CD31 and podoplanin in order to examine angiogenesis and lymphangiogenesis, respectively in common malignant tumors of salivary glands. MATERIALS AND METHODS: Forty formalin-fixed, paraffinated blocks (20 adenoid cystic carcinoma and 20 mucoepidermoid carcinoma blocks) were selected from the medical archives of Amir A'lam Hospital of Tehran, Iran. Sections from the blocks were stained by CD31 and D2-40 markers via immunohistochemistry. Clinical and demographic information was extracted from the patients' records. FINDINGS: There was a significant difference between tumors in terms of intratumoral microvessel density (MVD) (P< 0.001), total MVD (P< 0.001), and intratumoral lymphatic vessel density (LVD) (P= 0.011). In mucoepidermoid carcinoma, intratumoral MVD and LVD were greater than peritumoral MVD and LVD (P= 0.001 and P< 0.001, respectively). In mucoepidermoid carcinoma, there was no relationship between histological grade with MVD (total, intratumoral or peritumoral) or LVD (total, intratumoral or peritumoral) (P> 0.05). A similar finding was reported with respect to the histopathological grade of adenoid cystic carcinoma (P> 0.05). CONCLUSION: The higher level of angiogenesis and lymphangiogenesis in mucoepidermoid carcinoma, specifically at the center of tumor, compared to adenoid cystic carcinoma, may be attributed to differences in the clinical behaviors and metastasis of tumors. Moreover, considering the high LVD at the center of tumor in mucoepidermoid carcinoma and infrequency of metastasis to regional lymph nodes in adenoid cystic carcinoma, it can play a significant role in metastasis to regional lymph nodes.

Comparison of Salivary and Serum Soluble CD44 Levels between Patients with Oral SCC and Healthy Controls

Background: The most common type of oral cancer is oral squamous cell carcinoma. If it is diagnosed in the early stages; the success of the treatment can be increased. It seems that ELISA-based techniques as a screening tool for society are the most cost-effective methods for early diagnosis. CD44 is a key marker for the detection of SCC stem cells. The aim of this study was to compare the level of soluble CD44 in saliva and serum between patients with oral SCC and healthy controls. Materials and Methods: Saliva and serum were collected from 20 patients with primary OSCC and 20 healthy persons as control group. The samples were evaluated by an ELISA test kit. Data were analyzed by SPSS software version 22, chi-square, ANOVA, T-test and Spearman correlation test. Results: The mean of soluble CD44 level in serum and saliva of the patient and control groups are 531.51±228.95 and 453.3±113.74 (for serum) and 48.53±59.02 and 17.76±39.14 (for saliva) respectively. There was no statistically significant difference in serum and saliva solCD44 level between the patient and control groups (P value = 0.182 and P value = 0.061 respectively). Also, there was no significant correlation between the solCD44 level in each patient and control group in serum (P value = 0.61) and in saliva (P value = 0.445). Conclusions: Determination of solCD44 level in saliva and serum can be a useful method for diagnosis the person's involvement with cancer cells and the cancer in the early stages. But according to the controversial outcomes of past studies, larger and more accurate studies are needed in groups with more cases of oral cancer.

Immunohistochemical expression of TWIST in oral squamous cell carcinoma and its correlation with clinicopathologic factors.

BACKGROUND AND OBJECTIVES: TWIST is a transcription factor that plays a key role in the development of primary tumor to metastatic stage of cancer. It is an inhibitor of E-cadherin in epithelial-to-mesenchymal transformation process (epithelial-mesenchymal transition). Few studies are available on the use of TWIST as a goal in molecular-targeted therapy. The aim of this study was to evaluate of TWIST expression in oral squamous cell carcinoma (OSCC) and its correlation with clinicopathologic factors. MATERIALS AND METHODS: In this cross-sectional study, immunohistochemical staining was for TWIST performed on 30 paraffin-embedded blocks of OSCC. Furthermore, thirty paraffin-embedded blocks of normal oral mucosa with minimum inflammation from the clinical and histopathologic aspects were selected. Staining intensity and percentage of stained cells from nuclear and cytoplasmic aspects were ranked in epithelial cells. TWIST expression and correlation with clinicopathologic factors were analyzed using Cox regression and Chi-square tests. RESULTS: TWIST expression in OSCC was significantly increased compared to oral normal mucosa. Nuclear expression of TWIST in OSCC was significantly associated with clinical stage (P = 0.01) and lymph node metastasis (P = 0.007). Cytoplasmic expression of TWIST in OSCC was not associated with any clinicopathological factors. CONCLUSION: The results support the role of TWIST in carcinogenesis, development of OSCC, and its metastasis to lymph nodes.

HLA-G Expression is Associated with an Unfavorable Prognosis of Oral Squamous Cell Carcinoma

Background: HLA-G, a major histocompatibility complex of non-classical class Ib, plays a key role in the development of the primary tumors to metastatic stages. The aim of this study was to investigate HLA-G expression in oral squamous cell carcinomas and its relationship with clinicopathological factors. Methods: After immunohistochemical staining for HLA-G with 63 formalin fixed and paraffin embedded blocks (33 oral squamous cell carcinoma and 30 normal oral mucosa samples), staining intensity, percentage of stained cells and final immunoreactivity score were evaluated, along with other variables. Results: Staining intensity, percentage of stained cells and final immunoreactivity scores in oral squamous cell carcinomas were higher than those in normal oral mucosa (all P=0.001). The staining intensity in the parenchyma of squamous cell carcinoma cells was significantly associated with the clinical tumor stage (P=0.022) and the group with lymphatic metastasis exhibited a higher staining percentage (P=0.026). Staining intensity and immunoreactivity score (IRS) exhibited a significant but inverse correlation with survival rate (P=0.004 and P=0.018, respectively) and a significant direct relationship with clinical stage (P=0.001 and P=0.001). Conclusion: The results supported a role of HLA-G in development of oral squamous cell carcinomas and metastasis to lymph nodes. It might be useful in molecular-targeted therapy.

Evaluation of antibacterial properties of hydroxyapatite/bioactive glass and fluorapatite/bioactive glass nanocomposite foams as a cellular scaffold of bone tissue.

AIMS AND OBJECTIVES: Infection is a serious problem for patients after implantation surgery, which is difficult to treat with antibiotic therapy. The present study was developed to evaluate and compare the antibacterial properties of hydroxyapatite/bioactive glass (HA/BG) and fluorapatite/bioactive glass (FA/BG) nanocomposite foams as a cellular scaffold for use in bone defects by two macrodilution and disk diffusion methods. MATERIALS AND METHODS: Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans were cultured in brain heart infusion broth medium with nanocomposite powder for 5 days, and their bioactivity levels were evaluated by daily culturing on solid agar medium plates. To carry out the disk diffusion test, a disc form of nanocomposite foams was used on agar medium with 48 h incubation. RESULTS: None of two nanocomposites even at their highest concentration (200 mg/mL) did not prevent the growth of two Staphylococcus aureus and Enterococcus faecalis microorganisms. However, HA/BG nanocomposite on the 3rd day at a concentration of 200 mg/mL and on 4th and 5th day at a concentration of 100 mg/mL and FA/BG nanocomposite on the 4th day at a concentration of 100 mg/mL and on the 5th day at a concentration of 50 mg/mL could be able to kill Streptococcus mutans microorganism. In the disc diffusion test, none of the nanocomposites could create a nongrowth zone. Both tested biomaterials showed increased antibacterial properties over time and concentration increase. CONCLUSION: HA/BG and FA/BG nanocomposites, due to their biocompatibility and antimicrobial properties, are good choices for implantation instead of damaged bone tissue in tissue engineering.

A comparative study on cytotoxicity and genotoxicity of the hydroxyapatite-bioactive glass and fluorapatite-bioactive glass nanocomposite foams as tissue scaffold for bone repair.

Considering to the possibility of cellular and genetic damage by the implant materials in the patient and the clinician, the safety of the biomaterials should be evaluated. The purpose of this study was to compare the cytotoxicity and genotoxicity induced by two nanocomposites, hydroxyapatite/bioactive glass (HA/BG) and fluorapatite/bioactive glass (FA/BG) in vitro. Biomaterial extracts (BMEX, 100%) were prepared by incubating 100 mg/mL of each biomaterial powder in complete culture medium (RPMI1640 + 10% FBS) for 72 h. Saos-II cells were exposed to different concentrations of BMEXs for different periods of time and evaluated at the end of each period. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay results, both BMEXs at low concentrations (<25%) has no inhibitory effects on the cells growth. After 24 h of exposure, only HA/BG BMEX at 100% concentration showed significant cytotoxic effect. After 48 and 72 h, both HA/BG and FA/BG BMEXs showed similar cytotoxic effect at concentration higher than 75 and 50%, respectively. The results of the comet assay showed that the tail elongation, and proportionally DNA damage, increased in a dose/time dependently fashion with BMEXs exposure. Based on low and similar cytotoxicity and genotoxicity profiles on the Saos-II cell line, it could be concluded that FA/BG, like HA/BG, could be a good candidate for further in vivo biocompatibility studies to be used in bone tissue repair. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2605-2612, 2018.

Histopathological, histomorphometrical, and radiological evaluations of hydroxyapatite/bioactive glass and fluorapatite/bioactive glass nanocomposite foams as cell scaffolds in rat tibia: an in vivo study.

Bone defects are common and persistent problems in clinical orthopedics and dentistry. The development of synthetic reconstruction materials is essential owing to the restricted access to natural bone grafts, disease transmission risks, surgical costs, donor-site morbidity, infections, and immune response-related complications. The present study was done to evaluate the histopathological, histomorphometrical, and radiological characteristics of composite foams containing hydroxyapatite/bioactive glass (HA/BG) and fluorapatite/bioactive glass (FA/BG) as cell scaffolds in rat tibia reconstruction. A total of 60 rats were divided into four equal groups, of which three groups were implanted with HA/BG, FA/BG, and CenoBone® biomaterials, and the fourth group served as the implant-free controls. Five rats from each group were sacrificed at 15, 30, or 60 days after implantation, and radiological, histopathological, and histomorphometrical assessments were carried out. Based on the findings, no foreign body reaction was present in the rats. Additionally, bone-biomaterial contact occurred directly without the involvement of connective tissues. The number of osteoblasts was reduced in the implant groups, whereas the trabecular thickness and rate of new bone formation were increased in all groups, where the increase in the FA/BG group was the most prominent. The mean percentage difference in bone density between the implant site and the host bone was greater in the FA/BG group at all three time points of the study. Based on the results of the present study and the positive characteristics of these nanocomposite foams, they can be suitable options for implantation in damaged tissues in tissue engineering.

Astrocyte Elevated Gene 1 (AEG-1): A Promising Candidate for Molecular Targeted Therapy in Oral Squamous Cell Carcinomas

Background: Astrocyte elevated gene 1 (AEG-1), also known as metadherin, is an oncogene which is overexpressed in various types of cancer, playing important roles in invasion, metastasis, angiogenesis and chemotherapy resistance. Hence it might be used as a therapeutic target. The aim of this study was to evaluate the expression of AEG-1 as a novel molecular marker in oral squamous cell carcinomas and establish correlations with clinicopathologic factors. Materials and Methods: Thirty formalin fixed paraffin-embedded blocks of OSCC cases and 30 samples of normal oral mucosa with minimal inflammation were selected and stained immunohistochemically for AEG-1. Staining intensity and percentage of stained cells were scored according to nuclear and cytoplasmic staining of epithelial cells. Relationship between immunoreactivity and clinicopathologic factors were examined by T-test and Mann-Whitney. Results: AEG-1 expression in OSCCs was greater than in normal oral mucosa (P<0.05). However, nuclear and cytoplasmic expression of AEG-1 was not associated with any of the clinicopathologic factors, age and gender of patients, tumor location, smoking history, tumor staging and grading, metastasis to lymph nodes and distant metastasis ( P>0.05). Conclusion: The current results support some role of AEG-1 in genesis of oral squamous cell carcinomas.

Histological and histomorphometric evaluation of the synthetic biomaterial Natix® in horizontal reconstruction of alveolar ridge.

BACKGROUND: Following loss of teeth, atrophy of alveolar ridge of the jaws is a substantial problem and unintended outcome that compels clinicians to perform bone reconstruction ahead of implant placement. Although autogenous bone is recommended as the gold standard in bone reconstruction, aninvasive second surgery harvestinga limited volume of bone (from intraoral source) has led a significant approachingthe use of synthetic bone substitute materials. The aim of this study was to evaluate the histologic and histomorphometric properties of porous titanium granules (Natix®) used in horizontal reconstruction of alveolar ridge before implant placement. MATERIALS AND METHODS: In the present quasi-experimental clinical trial, four patients (three females and one male) needed horizontal bone augmentation on ten areas of edentulous mandibular ridge before implant treatment. During surgery, the buccal aspect of edentulous ridge was augmented by Natix®, covered by resorbable membrane (Cytoplast®). After 8 months, 10 core biopsies were obtained. RESULTS: In histological study, no foreign body reaction at the site of the newly formed bone or around the biomaterial residue was observed. Newly formed bone was fully vital with large lacunae containing osteocytes. In 60% of cases, connective tissue was observed at the biomaterial - new bone interface. In histomorphometric study, mean percentage of bone formation was 40.56% ± 19.83% and mean bone trabecular thickness was 39.98 ± 17.54 µ. CONCLUSION: Despite acceptable histological and histomorphometric bone formation findings, in clinical terms, no increase was created in the horizontal dimension. Thus, it seems that application of this biomaterial in horizontal reconstruction of alveolar ridges with noncontained defects is inappropriate.

VEGFR-3 Expression in Oral Lichen Planus

Background and objective: Given the postulated the role of inflammation and possible contribution of lymphangiogenesis in oral lichen planus, this study aimed to assess any associated presence of VEGFR-3. Material and Methods: This cross-sectional study was performed on 52 formalin fixed and paraffin embedded blocks of oral lichen planus (pathological diagnosis based on Modified WHO criteria), comprising 25 of erosive and 27 of reticular type, along with 60 samples of normal mucosa (with minimal inflammation from clinical and histopathological aspects) obtained at crown lengthening surgery. Four micron sections were cut from paraffin blocks and stained with H and E for confirmation of diagnosis and by immunohistochemistry with primary antibodies against VEGFR-3. Negative controls were provided by omission of primary antibody and placenta was considered as a positive control. Data were analyzed by Chi-square, Mann-Whitney and Kruskal-wallis tests and P <0.05 was considered statistically significant. Findings: VEGFR-3 expression was apparent in 61.5% of lichen planus specimens and 5% of those from normal mucosa (p<0.001). Also, the average number of stained vessels was significantly higher in oral lichen planus than in normal mucosa (p<0.001). VEGFR-3 expression in oral lichen planus (p=0.262) and the average number of stained vessels (p=0.092) demonstrated no significant difference according to the type. Conclusion: It appears that VEGFR-3 expression might be involved in the pathogenesis of the oral lichen planus through increasing lymphatic vessels and lymphangiogenesis.