Periodontal diseases are infectious diseases, but the specific mechanism by which the tooth-supportive tissue is destroyed is not clearly understood. Viral infection impairs periodontal defenses, thereby permitting subgingival overgrowth of periodontopathic bacteria. The role of viruses is significant, as they may induce abnormalities in the adhesion, chemotaxis, phagocytosis, and bactericidal activities of polymorphonuclear leukocytes. When associated with one another, viruses and bacteria have stronger periodontopathogenic potential than individually. Therefore, it is significant to know all etiologic factors and such an insight would lead to the better treatment of the disease.

Aim: The aim of this study was to evaluate surface and mechanical properties of bulk fill composite compared to conventional incremental composites. Materials and methods: The bulk fill composites were Filtek Bulk Fill, Sonic Fill, SDR Smart Dentin Replacement and Tetric-N-Ceram Bulk Fill while the incremental ones were Filtek Z350 × T and Herculite XRV Ultra. Surface roughness and wettability was measured using profilometer (Bruker) and drop shape analyzer (Kruss), respectively. Surface hardness of the top and bottom surface was measured using Micromet 6040 (Buehler). For mechanical test, the universal testing machine was used under the three-point bending test. Results: There was no statistical significant difference in wettability and surface roughness between bulk fill and incremental composites, except the SDR that showed statistically significance higher roughness than incremental composites. All composites showed significantly lower hardness than Filtek Z350; the lowest hardness was recorded for SDR. There was no significant difference between bulk fill and incremental composites in flexure strength and modulus. SDR showed the lowest flexure strength and modulus but the highest strain% (P < 0.05) compared to all tested materials. Sonic fill system showed significantly higher flexure strength and modulus when compared to other bulk fill materials (P < 0.05). Conclusion: The difference between bulk fill and incremental composite is mainly material dependent.

Context: Oral squamous cell carcinoma (OSCC) is the most common form of head and neck cancer, and over the last decade its incidence has increased by 50%. The tendency of OSCC for local and regional metastasis is high and this is thought to be the greatest contributor to the morbidity and mortality associated with OSCC. Aim: The aim of this study was directed to evaluate the role of both cluster of differentiation 44 (CD44) and cortactin (CTTN) in lymph node (LN) metastasis of OSCC. Materials and methods: The study groups comprised blocks of OSCC with LN metastasis (n = 20) and blocks of OSCC without LN metastasis (n = 20). The blocks were prepared for immunohistochemical staining for CD44 and CTTN. Results: The result of this study revealed significant correlation between expression of both CD44 and CTTN and LN metastasis. Conclusion: From the present study, it can be concluded that assessment of CD44 and CTTN in OSCC represent an important tool for prediction of risk of metastasis for each case and the significant correlation between CD44 and CTTN could provide insights of their critical role in metastasis.

Objective: The purpose of this in-vitro study was to investigate the effect of glow discharge and dielectric barrier discharge (DBD) plasma on repaired acrylic denture base resin as regard to shear bond strength and transverse strength. Materials and methods: Eighty specimens were prepared in this study, 30 for shear bond strength and 50 for transverse strength. Shear bond strength specimens are double fused discs. One disc prepared from heat-cured acrylic resin 15 mm × 3 mm. Glow discharge and DBD plasma with consumed energy of 360 and 720 J were used to treat the specimens. The surface of specimen was wetted with methylmethacrylate. The other disc, prepared from self-cured acrylic resin 6 mm × 2 mm, was attached to that surface as a repair material. Shear bond strength was determined using a universal testing machine. Transverse strength specimens were prepared in dimensions of 65 mm × 10 mm × 2.5 mm. Specimens were fractured, treated with plasma, wetted with methylmethacrylate then repaired. Transverse strength was measured by three-point bending test. Data were analyzed using one-way analysis of variance and Tukey's multiple comparison test interval at 0.05 level of significance. Results: There was a significant difference between the mean values of shear bond strength (MPa) and between the mean values of transverse strength (MPa) of repaired acrylic denture base resin (P < 0.05%). The highest shear bond strength was recorded with glow discharge at 720 J while the highest transverse strength was obtained with DBD plasma at 360 J. Conclusion: Using glow discharge plasma at 720 J as a surface treatment could increase the shear bond strength. Also, using DBD plasma treatment at 360 J could increase the transverse strength.

Purpose: To evaluate the remaining filling material (gutta-percha/EndoSequence bioceramic sealer) on root canal walls after retreatment using ProTaper universal retreatment (PTUR) system with and without chloroform solvent. Materials and methods: Thirty extracted human premolars with type I root canal system were used. After crown removal and working length determination, all root canals were prepared using nickel–titanium rotary ProTaper system and obturated using gutta-percha as a core filling material with EndoSequence bioceramic sealer. All roots were randomly divided into two equal main groups (n = 15) according to retreatment technique. Group I: filling materials was removed using PTUR system and chloroform as a solvent; while group II: filling materials was removed using PTUR system without solvent. Both groups were cleaved longitudinally and examined under scanning electron microscope to evaluate root canal filling remnants. Results: PTUR system with the aid of chloroform recorded highest values of score percentage of remaining filling material at all tested root canal levels. The values of score percentage of remaining filling materials were significantly lower at coronal level compared to other tested levels. Conclusion: Using chloroform during removal of root canal filling material using rotary instruments was associated with larger amount of residual root canal filling material compared to using rotary instruments only.

Background and objective: Recent findings have suggested that osteoclastogenesis is directly regulated by receptor activator of nuclear factor-κB ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG). Aim: Evaluate and compare the level of RANKL and OPG and its ratio (RANKL/OPG ratio) in saliva and gingival crevicular fluid (GCF) of patients with chronic periodontitis and clinically healthy individuals. Patients and methods: Ninety patients were selected and divided into group 1: 45 patients with clinically healthy gingiva as a control group. Group 2: 45 patients with moderate to severe chronic periodontitis probing pocket depth, bleeding on probing, plaque index and attachment level were measured, unstimulated whole saliva and GCF samples were collected from four deepest sites in different quadrants, both analyzed by enzyme-linked immunosorbent assays. Results: All periodontal indices (pocket depth, bleeding on probing, plaque index and attachment level) were significantly higher in the test groups than in the control group, it was found that RANKL and RANKL/OPG ratio significantly increased while OPG level significantly decreased in GCF and saliva in the chronic periodontitis group compared with the controlled group. Conclusion: Both GCF and saliva collection are a noninvasive approaches as a diagnostic markers for RANKL, OPG and RANKL/OPG ratio.

Purpose: The purpose of this study was to assess and compare wettability, dimensional changes, flexibility and tear resistance of two recent elastomeric impression materials, vinyl polyether silicone (VPES) hybrid material and polyvinyl siloxane (PVS) containing nanofillers with conventional PVS and polyether (PE) impression materials. Materials and methods: The elastomeric impression materials are divided into four groups, two experimental: VPES (EXA'lence) and PVS containing nanofillers (Elite HD+) and two control groups: PVS (Imprint II) and PE (Impregum Soft). The properties that were investigated are wettability, dimensional changes%, flexibility and tear resistance. Ten specimens were made for each property of all groups. Results: The results indicated that VPES (EXA'lence) and PE (Impregum Soft) showed the highest wettability. PVS containing nanofillers (Elite HD+) showed the lowest dimensional changes%. The strain in compression % (flexibility) of PE, VPES and PVS were not significantly different from each other and they were significantly different from PVS containing nanofillers which showed the lowest strain in compression%. The tear resistance (N/mm) of PVS containing nanofillers (Elite HD+) and VPES (EXA'lence) were significantly higher than PE (Impregum Soft) and PVS (Imprint II) which were not significantly different from each other. Conclusion: All tested materials were hydrophilic specially VPES and PE which recorded the highest wettability. All tested mterials showed accepted dimensional changes according to ANSI/ADA No. 19 and PVS containing nanofillers showed the greatest dimensional stability. All materials recorded accepted flexibility according to ANSI/ADA No. 19. As related to flexibility; PE, VPES and PVS recorded higher flexibility than PVS containing nanofillers while PVS containing nanofillers and VPES showed the highest tear resistance.

Aim: This study aimed to evaluate the fracture resistance of the rehabilitated overflared canals with anatomically adjustable everStick post. Patients and methods: Thirty extracted human maxillary central incisors with close similarity were selected. The specimens were coronally horizontally sectioned, endodontically treated and randomly divided into three groups (n = 10). Twenty of specimens were overflared, leaving 5 mm gutta percha seal. Group I: overflared specimens were rehabilitated with everStick post. Group II: overflared specimens were rehabilitated with EasyPost/composite. Group III (control group): specimens had normal unflared canals and were restored with EasyPost/core system. Composite resin was used to complete the core building-up for all groups. Fracture resistance of all specimens was measured using Instron testing machine. Statistical analyses were submitted to one-way analysis of variance and a post-hoc test. The level of significance was adopted atP value less than 0.05. Results: The results showed that the control group recorded the highest fracture resistance values, followed by everStick and EasyPost/composite group and the difference was significant among them (P < 0.05). Mode of failures showed 76.7% of specimens exhibited a repairable mode of failure while 23.3% displayed nonrepairable mode. Root fracture was recorded in one specimen of everStick group and in two specimens of EasyPost/composite group, however, four specimens in the control group displayed EasyPost fracture. Conclusion: The use of anatomically adjustable everStick post in rehabilitation of compromised teeth with flared canals seems to be significantly effective, promising in the improvement of fracture resistance, and increase the favorable mode of failure.