Purpose: This study was carried out to evaluate the effect of biostimulation on the regenerative response of immature teeth with necrotic pulp and apical periodontitis in dogs. Materials and Methods: Seventy-two root canals were employed in the present study as follows: Sixty root canals for experimental groups and twelve as positive and negative controls. After the induction of pulp necrosis and apical periodontitis, roots were divided into two groups, group I: Regenerative Endodontic Therapy (RET) with subsequent biostimulation (seven sessions at 808 nm diode laser at output power of 300 mW for 90 seconds) and group II: RET without biostimulation. The groups were followed up for 1, 2 and 3 months (subgroups A, B&C). The maturation of the roots was assessed both radiographically and histologically. All data were statistically analyzed.Results: the application of biostimulation in group I demonstrated marked increase in root length, thickness and decrease in apical diameter compared to group II however, it was statistically significant only in subgroup C (12.43% versus 7.66%, 33.09% versus 17.81% and 38.12% versus 23.35 % at third month) respectively (p<0.05). Furthermore, it showed histologically the highest score of vital tissue infiltration and least inflammatory scores which was statistically significant. Conclusion: Biostimulation enhanced the response of immature teeth with necrotic pulp and apical periodontitis to regenerative endodontic therapy improving root maturation.

Review: Benign Fibro-osseous lesions is a generic term that includes a group of diseases affecting jaw and facial bones. Myofibroblasts (MFs) are cells that share properties of fibroblasts and smooth muscle cells. They have a main role in tissue growth, development and healing, and during organ fibrosis and cancers. Alpha smooth muscle actin (α-SMA) is recognized to be present in smooth muscle cells, myoepithelial cells and pericytes. So it used to identify soft tissue neoplasms of smooth muscle, myoepithelial and myofibroblastic origin. Ki67 is one of the markers which is used to detect cellular proliferation in growing cells. Aim of study:The present study aimed to examine the immunohistochemical labeling of α-SMA in juvenile ossifying fibromas (JOFs), central ossifying fibromas (COFs) and peripheral ossifying fibromas (POFs) and to correlate its expression with their proliferative ability through Ki67 expression.Material and Methods: Immunohistochemical expression of α-SMA and Ki67 was evaluated in 10 samples of each of JOF, COF, and POF.Results: JOFs showed the highest mean value of α-SMA and Ki67 expression (16.69±5.25) (17.04±2.75) followed by COFs group (5.93±1.94) (8.33±1.23) while POFs showed the lowest mean value (1.54±0.64) (3.14±0.95), respectively, with a statistically significant positive correlation between α-SMA and Ki67 in all groups together (P-value ≤0.05). Conclusion:Overexpression and significant positive correlation between α-SMA and Ki67 expression in JOFs, COFs, and POFs indicate the important role of MFs in the aggressive behavior of JOFs when compared with COFs and POFs through enhancing cellular proliferation, cellular migration, angiogenesis, and extracellular proteolytic activity and influencing matrix formation.

BACKGROUND: Photochemotherapy is thought to be a novel therapeutic modality for cancer. The photobiomodulation (PBM), applied through high fluence low-level laser irradiation (HF-LLLI), can be combined with the chemotherapeutic drug cisplatin to gain the benefit of potentiating its cytotoxic effect at possibly lower doses. AIM: The study aimed at investigation of the apoptotic effect of PBM, through LLLI (at HF), alone and in combination with cisplatin on cultured laryngeal cancer (HEp-2) cells. MATERIALS AND METHODS: In the current experimental in vitro research, cultured laryngeal cancer cell line (HEp-2) was treated with the half maximal inhibitory concentration of cisplatin, with and without LLLI. The study design consisted of four groups: Control (untreated), cisplatin-alone-treated, PBM-alone-treated, and combination cisplatin + PBM treated groups. Cells were irradiated once with diode laser (wavelength 808 nm, energy output 350 mW, 3 min, fluence 190.91 J/cm2, and continuous wave mode). Cytotoxicity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay and the potential apoptotic effect was evaluated by cytochrome c (CYC) release through enzyme-linked immunosorbent assay (ELISA), in conjunction with visualization of cytomorphologic alterations by light microscopic examination, followed by digital morphometric analysis of nuclear changes through estimation of nuclear area factor (NAF). Analysis of variance and post hoc multiple-comparison tests were used for statistical analysis of the data of cytotoxicity assay, ELISA, and nuclear morphometric analysis. RESULTS: PBM alone had a neutral effect on viability of HEp-2 cells, but it induced CYC release and lowered NAF mean value, significantly. When PBM was combined with cisplatin, more conspicuous deterioration in bioavailability of HEp-2 cells was observed, a higher amount of CYC was liberated and NAF value dropped in HEp-2 cells, compared to those which received separate treatments with cisplatin alone or PBM alone. CONCLUSION: Based on the current findings, low-level laser photochemotherapy might be a promising adjunctive anticancer treatment for laryngeal cancer, as PBM at HF was able to augment the apoptotic effect of cisplatin on HEp-2 cancer cells.

Review: Ameloblastoma (AM), the most frequently reported tumor originating from odontogenic epithelium, is characterized by a benign but locally invasive behavior with a high risk of recurrence. Hybrid odontogenic tumors (HOTs) consist of two distinct and separable entities growing into single mass clinically as well as microscopically. The exact cause for such an occurrence is not clarified. Epithelial mesenchymal transition (EMT) plays a pivotal role in facilitating the migratory and invasive capabilities of many tumor cell types. E-cadherin functions as an invasion suppressor gene and its expression is decreased in most neoplasms while high osteopontin (OPN) expression is correlated with poor prognosis in different tumors. Aim of study:The current study aimed to examine the expression of E-Cadherin and OPN in conventional multicystic ameloblastoma (CMAM) and hybrid ameloblastoma (HAM) and correlate their expression with local invasion and aggressive behavior in both lesions.Material and Methods: Immunohistochemical expression of E cadherin and OPN was evaluated in 7 samples of CMAM cases and 7 samples of HAM.Results: CMAM expression for E-cadherin and OPN, was significantly different from HAM (P-value ≤ 0.05), the CMAM showed the highest mean value for OPN (17.14±5.11) while HAM showed the higher mean value for E-cadherin expression (13.08±2.15) with statistically nonsignificant negative relation between E-cadherin and OPN (P-value >0.05) in both lesions. Conclusion:The higher expression of OPN and lower expression of E-cadherin in CMAM in comparison with HAM indicate that CMAM has local invasion and more aggressive behavior than HAM.

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