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1.
Eur J Dent ; 2024 May 22.
Article in English | MEDLINE | ID: mdl-38776980

ABSTRACT

OBJECTIVE: The aim of this study was to determine the effect of two acidic beverages (orange juice and H3PO4-containing fizzy drink) on the surface topography and color stability of two commonly used computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic materials. MATERIALS AND METHODS: Sixty samples of two CAD/CAM ceramic materials, lithium disilicate (IPS e-max CAD) and zirconia reinforced lithium silicate (Vita Suprinity), were prepared according to the manufacturer's instructions. The samples were immersed in one of three media (artificial saliva, orange juice and H3PO4-containing fizzy drink) and then stored in an incubator at 37 °C for 24 hours). Before and after immersion in different media, the surface roughness (Ra) of the samples was assessed using profilometer (JITAI8101 Surface Roughness Tester-Beijing Jitai Tech Detection Device Co. Ltd, China) and the color parameters were measured using VITA Easyshade Advance 4.01 (VITA shade, VITA made, VITA). Surface topography was observed using scanning electron microscope (SEM) and surface mineral content was compared before and after immersion. Paired sample t-test was used to determine the change in Ra before and after immersion. Two-way analysis of variance was used to determine the effect of different CAD/CAM materials and immersion media on the mean ∆Ra and mean ∆E of the studied groups. Tukey's honest significant difference posthoc test was used for multiple comparisons at a level of significance (α = 0.05). RESULTS: A significant increase in Ra and a decrease in the color stability of the two investigated ceramic materials were detected after immersion in the acidic media than in artificial saliva. SEM and energy-dispersive X-ray results revealed the dissolution of the glassy matrix and the exposure of silicate crystals. CONCLUSION: The surface topography and color stability of glass ceramics are affected by the pH of different acidic media.

2.
Eur J Dent ; 2024 May 24.
Article in English | MEDLINE | ID: mdl-38788769

ABSTRACT

OBJECTIVES: This study aimed to examine the suppressive effect of the natural antioxidant vitamin C (VC) against submandibular gland toxicity induced by copper oxide nanoparticles (CuO-NPs). MATERIALS AND METHODS: Three groups of 30 mature male albino rats (4 weeks old) weighing between 150 and 200 g were selected. The rats were randomly assigned for 6 weeks to receive: intraperitoneal injection (IP) of vehicle (control group); IP of 2.5 mg/kg body weight (bw) of CuO-NPs (CuO-NPs group); and IP of 2.5 mg/kg bw of CuO-NPs, combined with a daily oral dose of 100 mg/kg bw of VC in drinking water via gavage (CuO-NPs/VC group). The rats were euthanized, and their submandibular glands were dissected for histological evaluation, including hematoxylin and eosin staining and immunohistochemistry for Ki-67 and caspase-3. STATISTICAL ANALYSIS: The area expression for Ki-67 and caspase-3 was statistically analyzed using GraphPad Prism. Following analysis of variance analysis, Tukey's post hoc was used for multiple comparisons. The significance level was set at p < 0.05. RESULTS: CuO-NPs caused significant cytotoxic effects on submandibular salivary gland cells in albino rats. This led to an increase in Ki-67 and caspase-3 levels compared with the control group. VC administration improved tissue histology and reduced Ki-67 and caspase-3 levels in the VC/CuO-NPs group compared with rats treated with CuO-NPs alone. CONCLUSION: The study revealed significant cytotoxic effects of CuO-NPs on the submandibular salivary gland of albino rats. VC effectively mitigated these toxic effects, suggesting its potential as a readily available antioxidant.

3.
Int J Biol Macromol ; 264(Pt 1): 130448, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38428756

ABSTRACT

As lignocellulose recalcitrance principally restricts for a cost-effective conversion into biofuels and bioproducts, this study re-selected the brittle stalk of corn mutant by MuDR-transposon insertion, and detected much reduced cellulose polymerization and crystallinity. Using recyclable CaO chemical for biomass pretreatment, we determined a consistently enhanced enzymatic saccharification of pretreated corn brittle stalk for higher-yield bioethanol conversion. Furthermore, the enzyme-undigestible lignocellulose was treated with two-step thermal-chemical processes via FeCl2 catalysis and KOH activation to generate the biochar with significantly raised adsorption capacities with two industry dyes (methylene blue and Congo red). However, the desirable biochar was attained from one-step KOH treatment with the entire brittle stalk, which was characterized as the highly-porous nanocarbon that is of the largest specific surface area at 1697.34 m2/g and 2-fold higher dyes adsorption. Notably, this nanocarbon enabled to eliminate the most toxic compounds released from CaO pretreatment and enzymatic hydrolysis, and also showed much improved electrochemical performance with specific capacitance at 205 F/g. Hence, this work has raised a mechanism model to interpret how the recalcitrance-reduced lignocellulose is convertible for high-yield bioethanol and multiple-function biochar with high performance.


Subject(s)
Cellulose , Charcoal , Zea mays , Cellulose/chemistry , Zea mays/chemistry , Polymerization , Coloring Agents
4.
Eur J Dent ; 2024 Mar 31.
Article in English | MEDLINE | ID: mdl-38555644

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the effects of two intraoral polishing methods on zirconia-reinforced lithium silicate ceramic after ultrasonic scaling. MATERIALS AND METHODS: Thirty disc-shaped samples of zirconia-reinforced lithium silicate were constructed. Freshly extracted bovine teeth were collected and cleaned then the discs were cemented into a cavity prepared onto their labial surface. The samples were divided into three groups (10 samples per group); S: Scaling only, SE: Scaling followed by polishing using Eve Diapro lithium disilicate polishers, SD: Scaling followed by polishing using Diatech ShapeGuard ceramic polishing plus kit. The surface roughness was evaluated after scaling and polishing the samples. For color stability, the samples were stored for 12 days at 37°C in an incubator to simulate 1-year consumption of coffee. L*a*b* color parameters were assessed using VITA Easyshade Advance 4.0 before and after the staining procedure and the color difference was measured. Finally, bacterial accumulation was evaluated by incubating the samples with a suspension of Streptococcus mutans ( S. mutans), after that the S. mutans colonies were counted to obtain the values of colony-forming units (CFU). The final overall roughness, change in color and bacterial count were compared between all groups using one-way ANOVA and Tukey's post-hoc analysis. The Pearson correlation coefficient was used to determine the correlation between continuous variables. The cutoff for significance was chosen at p ≤ 0.05. RESULTS: Scaling induced surface roughness of the zirconia-reinforced lithium silicate ceramic was significantly decreased after using both intraoral polishing systems and this was accompanied by a significant decrease in color change and bacterial count. CONCLUSION: Intraoral polishing techniques can reduce the roughness of the surface of zirconia reinforced lithium silicate restorations induced due to scaling and subsequently reduce the stainability and bacterial accumulation.

5.
Heliyon ; 10(1): e23792, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38223712

ABSTRACT

Statement of problem: There are very few studies using Benzalkonium Chloride (BAC) as an active disinfection agent for immersion techniques and there are no studies investigating the efficacy of repeated use of a disinfectant solution. Purpose: This study evaluated an impression disinfectant by testing bacterial contamination of disinfectant batches used in a clinical setting after repeated use. Materials and methods: Liquid samples were collected from impression disinfectant solutions used to disinfect dental impressions taken at a university dental clinic. The experimental samples (500 ml from 1 L of solution) were collected from teaching and professional clinics and the in-house commercial processing laboratory and stored at room temperature each day of clinic operation over five weeks. To determine to what extent the disinfectant efficacy of the active product decreased over time, the following tests were carried out: a. Inoculation b. Gram staining technique c. Matrix Assisted Laser Desorption/Ionization Mass spectrometry (MALDI- MS). Microbial growth was monitored and photographed. A culture revival was made from colonies grown on sheep blood agar, to isolate pure colonies incubated for 24 h at 37 °C. Each morphologically distinct type of colony was gram stained and MALDI spectrometry analysis was performed using the VITEK MS (BioMerieux Inc.). Results: Evidence of growth of bacteria was detected in teaching clinics' samples, and no growth from the professional clinic or the commercial laboratory. Conclusions: The study demonstrated that the impression disinfectant solution tested is effective against common oral bacteria, despite some rare species such as Bacillus circulans, Bacillus horneckiae, Bacillus altitudinis/pumilus and Bacillus cereus showing evidence of survival in solutions used for disinfection of impressions. However, in a high use teaching clinic environment its efficacy deteriorated. Though a second level disinfection protocol in the commercial laboratory-maintained impression disinfection.

6.
Clin Exp Dent Res ; 10(1): e816, 2024 02.
Article in English | MEDLINE | ID: mdl-38053499

ABSTRACT

OBJECTIVES: Migration and differentiation of human dental pulp stem cells (hDPSCs) is a vital and key factor in the success of reparative dentin formation for maintenance of pulp vitality. Pulp capping materials are used to stimulate DPSCs to induce new dentin formation. Thus, the aim of the present study was to compare the response of DPSCs to four commercially available pulp capping materials: a bioactive bioceramic (Material 1), a nonresinous ready-to-use bioceramic cement (Material 2), a bioactive composite (Material 3), and a biocompatible, dual-cured, resin-modified calcium silicate (Material 4). MATERIALS AND METHODS: hDPSCs were isolated and cultured from freshly extracted teeth and were then characterized by flow cytometry and multilineage differentiation. Discs prepared from pulp capping materials were tested with hDPSCs and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, cell migration assay and odontogenic differentiation assay was performed. Expression of osteogenic markers (osteopontin, RUNX family transcription factor 2, osteocalcin) and the odontogenic marker (dentin sialophosphoprotein) was detected using reverse transcription-polymerase chain reaction. RESULTS: Materials 1, 2, and 3 generated more cell viability than Material 4. Furthermore, Material 4 showed the least wound exposure percentage, while Material 3 showed the highest percentage. Enhanced mineralization was found in hDSCPs cultured with Material 3, followed by Material 1, and then Material 2, while Material 4 revealed the least calcified mineralization. CONCLUSIONS: The results of this study were inconclusive regards contemporary bioceramic materials designed for vital pulp therapy as they have different effects on hDPSC. Further testing for cytotoxicity using live-dead staining, animal experiments, clinical trials, and independent analyses of these biomaterials is necessary for clinicians to make an informed decision for their use.


Subject(s)
Dental Pulp Capping , Dental Pulp , Animals , Humans , Odontogenesis , Cell Differentiation , Stem Cells
7.
Iran Endod J ; 18(4): 224-232, 2023.
Article in English | MEDLINE | ID: mdl-37829828

ABSTRACT

Introduction: This in vitro study aimed to evaluate the effect of different irrigation regimens on the chemical composition and cleanliness of root canal dentin. Materials and Methods: Forty-eight extracted single-rooted permanent human teeth were collected. Root canals were instrumented using step-back technique up to master apical file size 60. Samples were divided into 3 groups (n=16) based on the type of the irrigant used. The irrigation solutions were 5.25% sodium hypochlorite, 2% chlorhexidine gluconate, and saline solution as a control. Root canal cleanliness was assessed using stereomicroscope and scanning electron microscope. Scanning electron microscope energy dispersive X-ray was used for the inorganic analysis. Fourier transform infrared spectrometer was used for the organic analysis. One-way analysis of variance (ANOVA) and multiple comparison post hoc test were used for comparison between the three groups. Results: The highest mean percentage of remaining debris was in saline group followed by chlorhexidine gluconate group. Sodium hypochlorite group showed the lowest mean value of remaining debris. Furthermore, our results showed that canal irrigation with sodium hypochlorite affected the chemical structure of root canal dentin more than chlorhexidine gluconate. Conclusions: Based on the results, 5.25% sodium hypochlorite emerges as the preferred irrigant for root canal treatment. This research sheds light on the significance of irrigation regimens in endodontics and emphasizes the need for careful consideration of irrigant selection in clinical practice.

8.
Cleft Palate Craniofac J ; 60(11): 1426-1441, 2023 11.
Article in English | MEDLINE | ID: mdl-35642284

ABSTRACT

The aim of the study was to investigate the microbial colonization (by Candida species, anaerobic and facultative anaerobic bacteria) of maxillary obturators used for the restoration of maxillary defects, including during radiotherapy.Retrospective cohort study.Fifteen patients requiring a maxillary obturator prosthesis had swabs of their obturators and adjacent tissues taken at different stages of their treatment over a period of 8 years.Identification of microbial species from the swabs was carried out using randomly amplified polymorphic DNA polymerase chain reaction (RAPD PCR) analysis, checkerboard DNA-DNA hybridization, CHROMagar Candida chromogenic agar, and DNA sequencing.Candida species were detected in all patients and all patients developed mucositis and candidiasis during radiotherapy which was associated with an increase in colonization of surfaces with Candida spp., particularly C albicans. Microbial colonization increased during radiotherapy and as an obturator aged, and decreased following a reline, delivery of a new prosthesis, or antifungal treatment during radiotherapy.Microbial colonization of maxillary obturators was related to the stage of treatment, age of the obturator material, radiotherapy and antifungal medications, and antifungal treatment may be recommended if C albicans colonization of palatal tissues is greater than 105 colony-forming units per cm2 following the first week of radiotherapy.


Subject(s)
Antifungal Agents , Prosthodontics , Aged , Humans , Candida/genetics , Palatal Obturators , Random Amplified Polymorphic DNA Technique , Retrospective Studies
9.
Bioengineering (Basel) ; 8(12)2021 Dec 16.
Article in English | MEDLINE | ID: mdl-34940372

ABSTRACT

Silver nanoparticles (AgNPs) are extensively used in many industries due to their superior antimicrobial properties. However, it is evident from many studies that AgNPs has cytotoxic potential through its effect on excessive formation of reactive oxygen species (ROS). The aim of this study was to examine the toxic effect of AgNPs on the submandibular salivary glands and the attenuating effect of vitamin E, as a natural antioxidant, against this toxicity. Thirty Albino rats were divided into 3 groups (n = 10): control group, AgNPs group receiving 2 mg/kg daily for 28 days, and AgNPs and vitamin E group receiving AgNPs the same as the previous group in addition to vitamin E at a dose of 100 mg/kg. Microscopic, ultrastructural, and cytokeratin immune-reactivity examination of the glands were performed. The AgNPs group showed noticeable degeneration in all structures of the gland as evident in the histological and ultrastructural examination. The AgNPs and vitamin E group revealed an improvement of the glandular elements. A significant increase in cytokeratin immune expression was found after comparison of both groups (p = 0.01). This current study shows that vitamin E has powerful antioxidant properties, which can combat the cytotoxic effect caused by AgNPs. Further studies are deemed necessary to confirm this finding using other immunohistochemical markers, such as myosin and E-cadherin.

10.
JBMR Plus ; 4(9): e10387, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32995690

ABSTRACT

Parathyroid hormone (PTH) and bisphosphonates (BPs), including alendronate (ALN), have opposing effects on bone dynamics. The extent to which PTH remains effective in the treatment of stress fracture (SFx) in the presence of an ongoing BP treatment has not been tested. SFx was induced in 150 female Wistar rats, divided into five equal groups (n = 30). All rats were pretreated with ALN (1 µg/kg-1/day-1) for 14 days prior to SFx induction, followed by ALN cessation or continuation for the duration of the experiment; this was combined with daily PTH (8 µg/100 g-1/day-1) on SFx induction for 14 days, followed by cessation or continuation of ALN after SFx induction or an equivalent vehicle as a control. Ulnas were examined 2 weeks or 6 weeks following SFx. Two toluidine blue- and two tartrate-resistant acid phosphatase-stained sections were examined for histomorphometric analysis using Osteomeasure software. There was a significant interaction between the effects of time and treatment type on the woven bone width and apposition rate, as well as an improvement in the woven bone architecture. However, woven bone variables remained unaffected by the cessation or continuation of ALN. Cessation of ALN increased osteoclast number when compared with the ALN-PTH continuation group (p = 0.006), and vehicle (p = 0.024) after 2 weeks. There was a significant interaction between the effects of time and treatment type on the number of osteoclasts per unit BMU area and length. The number of osteoclasts per unit BMU area and length was significantly greater in ALN cessation groups. It was concluded that intermittent short-duration iPTH treatment effectively increased remodeling of SFx with a concurrent BP treatment, provided that BP was ceased at the time of SFx. Our results could help develop shorter iPTH treatment protocols for the clinical management of SFxs and guide clinical decision-making to cease BP treatment in cases of SFx. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

11.
Bioengineering (Basel) ; 7(3)2020 Aug 11.
Article in English | MEDLINE | ID: mdl-32796620

ABSTRACT

The aim of the study was to investigate the effects of neodymium: yttrium aluminium garnet (Nd:YAG) (1064 nm) and erbium: yttrium aluminium garnet (Er:YAG) (2940 nm) laser energy on titanium when delivered with conventional optics (focusing handpieces or plain ended optical fibres) or with a conical tip. Machined and micro-roughened implant discs were subjected to laser irradiation under a variety of energy settings either dry (without water) or wet (with water). Samples were scanned using a 3D non-contact laser profilometer and analysed for surface roughness, volume of peaks and the maximum diameter of the ablated area. Conical tip designs when used with both lasers showed no surface effect at any power setting on both machined and micro-roughened implant surfaces, regardless of the irrigation condition. When used with conventional delivery systems, laser effects on titanium were dose related, and were more profound with the Nd:YAG than with the Er:YAG laser. High laser pulse energies caused surface fusion which reduced the roughness of micro-roughened titanium surfaces. Likewise, repeated pulses and higher power densities also caused greater surface modifications. The presence of water reduced the influence of laser irradiation on titanium. It may be concluded that conical fibres can reduce unwanted surface modification, and this may be relevant to clinical protocols for debridement or disinfection of titanium dental implants.

12.
Br Dent J ; 228(11): 886-892, 2020 06.
Article in English | MEDLINE | ID: mdl-32541753

ABSTRACT

In the past, osteonecrosis of the jaw (ONJ) was generally reported with bisphosphonate drugs; hence, the term BRONJ (bisphosphonate-related osteonecrosis of the jaw) was initially proposed. This was followed by the term ARONJ (antiresorptive osteonecrosis of the jaw). More recently, other novel medications such as vascular endothelial growth factor (VEGF) inhibitors, tyrosine kinase inhibitors and humanised antibodies that affect osteoclastic action have been reported to initiate ONJ in several cases. For this reason, in 2014, the American Association of Oral and Maxillofacial Surgeons (AAOMS) changed the term to MRONJ - medication-related osteonecrosis of the jaw. The review primarily focuses on ONJ associated with emerging therapies for the management of bone disorders. This article sheds some light on the risk factors that predispose dental patients to the development of osteonecrosis, the mechanisms of drug therapies associated with MRONJ, and potential treatment and management regimes for MRONJ patients. The current review noted that the incidence and associated risk of MRONJ is significant with the new therapeutic agents discussed. Therefore, for optimised patient care, pharmacovigilance with the new medications is essential for dental professionals.


Subject(s)
Bisphosphonate-Associated Osteonecrosis of the Jaw , Bone Density Conservation Agents , Medicine , Osteonecrosis , Bisphosphonate-Associated Osteonecrosis of the Jaw/epidemiology , Bisphosphonate-Associated Osteonecrosis of the Jaw/etiology , Bisphosphonate-Associated Osteonecrosis of the Jaw/therapy , Bone Density Conservation Agents/adverse effects , Diphosphonates/adverse effects , Humans , Osteonecrosis/chemically induced , Vascular Endothelial Growth Factor A
13.
Cleft Palate Craniofac J ; 57(4): 487-498, 2020 04.
Article in English | MEDLINE | ID: mdl-31665902

ABSTRACT

BACKGROUND: Maxillofacial prosthetics includes restoration of maxillary defects resulting from resection of palate and nasosinus neoplasms with obturator prostheses which may be colonized by microorganisms and function as a reservoir of infection. Patients with neoplasms commonly also require radiotherapy that can result in changes in saliva quality and quantity and changes in the oral microbial flora. The altered flora, in individuals immunocompromised from cancer therapy, increases their risk of prosthesis-related infections. OBJECTIVES: In this review article, we explore microbial biofilms, their main components, mechanisms of microbial adhesion, and stages of biofilm development. We also discuss the different materials that are used for manufacturing maxillary obturators, their characteristic features, and how these can affect microbial adhesion. Furthermore, we shed some light on the factors that affect microbial adhesion to the surface of maxillary obturators including tissue proteins, protein adsorption, and the acquired enamel pellicle. CONCLUSIONS: The conclusions drawn from this literature review are that it is imperative to minimize the risk of local and systemic infections in immunocompromised patients with cancer having maxillary defects. It is also important to determine the role of saliva in microbial adhesion to obturator materials as well as develop materials that have a longer life span with surface characteristics that promote less microbial adhesion than current materials.


Subject(s)
Dental Implants , Maxillary Neoplasms , Biofilms , Humans , Maxilla , Palatal Obturators
14.
F1000Res ; 8: 1764, 2019.
Article in English | MEDLINE | ID: mdl-31839926

ABSTRACT

Background: Tooth whitening usually includes the direct use of gels containing carbamide or hydrogen peroxide on the tooth enamel surface through a wide variety of products formulas. A generally new advancement in whitening of teeth uses the significant importance of the tooth color shift from yellow to blue in delivering a general enhancement in the observation of tooth whiteness. The aim of the current work was to measure the tooth whitening effects, surface roughness and enamel morphology of six different types of blue covarine-containing and blue covarine-free toothpastes using in vitro models. Methods: A total of 70 sound extracted human premolars were randomly and equally divided into seven groups, and each subjected to tooth brushing using different toothpastes. Tooth color and enamel surface roughness were measured before and after the brushing procedure using a white light interferometer, and scanning electron microscopy (SEM) was used to assess tooth surface after the procedure. Results: Toothpaste containing blue covarine resulted in the greatest improvement in tooth color amongst all groups as well as a statistically significant color difference when compared to blue covarine-free toothpaste.  Furthermore, blue covarine-containing toothpaste resulted in fewer morphological changes to the enamel surface. This was confirmed with SEM images that showed smooth enamel surfaces with fine scratches.   Conclusions: The results from the present study show that blue covarine containing toothpastes are reliable, effective in tooth whitening and produce less surface abrasion when compared to blue covarine-free toothpastes.


Subject(s)
Tooth , Coloring Agents , Dental Enamel , Humans , Tooth Bleaching , Toothpastes
15.
J Orthop Res ; 37(5): 1172-1182, 2019 05.
Article in English | MEDLINE | ID: mdl-30816593

ABSTRACT

Stress fractures (SFx) result from repetitive cyclical loading of bone. They are frequent athletic injuries and underlie atypical femoral fractures following long-term bisphosphonate (BP) therapy. We investigated the effect of a single PTH injection on the healing of SFx in the rat ulna. SFx was induced in 120 female Wistar rats (300 ± 15 g) during a single loading session. A single PTH (8 µg.100g-1 ) or vehicle (VEH) saline injection was administered 24 h after loading. Rats were divided into four groups (n = 15) and ulnae were examined 1, 2, 6, or 10 weeks following SFx. Two Toluidine Blue and TRAP-stained sections of the SFx were examined for histomorphometric analysis using Osteomeasure™ software. An increase in osteoclast number (N.Oc) and perimeter (Oc.Pm) was observed two weeks following PTH treatment (p < 0.01). At 6 weeks, bone formation was the main activity in BMUs. At 10 weeks, the proportion of healing along the SFx line remained 50% greater in PTH groups (p = 0.839), leading to a 43% reduction in the porosity area of BMU (p = 0.703). The main effect of time was a significant variable along the entire SFx remodeling cycle, with significant interactions between time and treatment type affecting (N.Oc) (p = 0.047) and (Oc.Pm) (p = 0.002). We conclude that a single PTH injection increases osteoclastogenesis by the second week of the remodeling cycle in a SFx in vivo. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.


Subject(s)
Bone Remodeling/drug effects , Calcium-Regulating Hormones and Agents/administration & dosage , Fracture Healing/drug effects , Fractures, Stress/drug therapy , Parathyroid Hormone/administration & dosage , Ulna Fractures/drug therapy , Animals , Drug Evaluation, Preclinical , Female , Osteoclasts , Porosity , Rats, Wistar
16.
Article in English | MEDLINE | ID: mdl-29550080

ABSTRACT

OBJECTIVES: The aim of this study was to identify an association or link between cyclin D1 and p27KIP1 protein expression and dysplastic changes or progression. STUDY DESIGN: Oral mucosal biopsies with a diagnosis of non-neoplastic tissue (gingivitis) (n = 10), mild to moderate oral epithelial dysplasia (n = 12), and oral squamous cell carcinoma (n = 11) were evaluated by using immunohistochemistry. Scanning software was used to determine cyclin D1 and p27KIP1 intensity of expression, location, and pattern. RESULTS: A significant increase in expression of cyclin D1 and a decrease in expression of p27KIP1 proteins were identified in oral epithelial dysplasia and less differentiated oral squamous cell carcinoma (OSCC). There was a more diffuse distribution of cyclin D1 protein expression extending from the basal cell layer into the prickle cell layers in epithelial dysplasia and extending within all epithelial layers in OSCC. Cases of oral epithelial dysplasia had moderate infrequent expression of p27KIP1. There were no p27KIP1-positive cells in OSCC. The percentage of cells with both nuclear and cytoplasmic cyclin D1 staining was higher in OSCC specimens than control groups and oral epithelial dysplasia. CONCLUSIONS: The expression of both cyclin D1 and p27KIP1 correlated with the grade of oral epithelial dysplasia and degree of OSCC differentiation. The results obtained will be verified through a basic follow-up of the cases to determine the prognosis/progression of oral dysplasia.


Subject(s)
Carcinoma, Squamous Cell/metabolism , Cyclin D1/metabolism , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Mouth Neoplasms/metabolism , Precancerous Conditions/metabolism , Biopsy , Cell Differentiation , Cell Transformation, Neoplastic , Humans , Immunohistochemistry
17.
F1000Res ; 7: 1819, 2018.
Article in English | MEDLINE | ID: mdl-30631444

ABSTRACT

Background: Toll-like receptor-2 (TLR2) is highly important within the immune system. Characterization of the expression of TLR2 within inflammatory cells in periapical lesions could help in diagnosis and management of refractory cases. The aim of the study is identification of Toll-like receptor (TLR2) through immunohistochemical and immunofluroscence expression in inflammatory cells within refractory periapical granuloma cases. Methods: Eight cases of refractory periapical granuloma were selected out of 772 cases. Histological examination and immunohistochemical staining with polyclonal rabbit antihuman TLR2, monoclonal mouse antihuman CD38, CD68 and CD83 primary antibodies, as well as immunofluorescence staining with goat anti-rabbit TLR2, donkey anti-mouse CD38, CD68 and CD83 primary antibodies was conducted. Positive controls, negative controls and experimental sections with no primary antibody were included in the study. Qualitative analysis and double immunofluorescence technique was used to characterize the TLR + cells. Results: In periapical granuloma, lymphocytes (CD38 cells) expressed the most amount of TLR reactivity followed by macrophages (CD68 cells), and odontogenic epithelial cells. Neutrophils, red blood cells (RBCs) and collagen ground substance were negative to TLR2.  Conclusion: TLR2 was highly expressed by lymphocytes and plasma cells indicative of their major role in the inflammatory process and antigen recognition in refractory periapical granuloma. Dendritic cells expressing TLR2 were low in number suggesting a minor role in sustaining these lesions.


Subject(s)
Inflammation/metabolism , Inflammation/pathology , Periapical Granuloma/metabolism , Toll-Like Receptor 2/metabolism , Antigens, CD/metabolism , Germinal Center/metabolism , Humans , Periapical Granuloma/pathology
18.
Saudi Dent J ; 29(2): 41-47, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28490842

ABSTRACT

Virtual reality simulators are becoming an essential part of modern education. The benefits of Virtual reality in dentistry is constantly being assessed as a method or an adjunct to improve fine motor skills, hand-eye coordination in pre-clinical settings and overcome the monetary and intellectual challenges involved with such training. This article, while providing an overview of the virtual reality dental simulators, also looks at the link between virtual reality simulation and current pedagogical knowledge.

19.
Anat Sci Educ ; 10(4): 395-404, 2017 Jul.
Article in English | MEDLINE | ID: mdl-27585370

ABSTRACT

Basic science courses are extremely important as a foundation for scaffolding knowledge and then applying it in future courses, clinical situations as well as in a professional career. Anatomical sciences, which include tooth morphology, oral histology, oral embryology, and head and neck anatomy form a core part of the preclinical courses in dental technology programs. In this article, the importance and relevance of anatomical sciences to dental personnel with no direct contact with patients (dental technicians) and limited discipline related contact with patients (dental prosthetists) is highlighted. Some light is shed on the role of anatomical sciences in the pedagogical framework and its significance in the educational process and interprofessional learning of dental technicians and prosthetists using oral biology as an example in the dental curriculum. To conclude, anatomical sciences allow dental technicians and prosthetists to a gain a better insight of how tissues function, leading to a better understanding of diagnosis, comprehensive treatment planning and referrals if needed. Patient communication and satisfaction also increases as a result of this deep understanding of oral tissues. Anatomical sciences bridge the gap between basic science, preclinical, and clinical courses, which leads to a holistic approach in patient management. Finally, treatment outcomes are positively affected due to the appreciation of the macro and micro structure of oral tissues. Anat Sci Educ 10: 395-404. © 2016 American Association of Anatomists.


Subject(s)
Anatomy, Regional/education , Education, Dental/methods , Problem-Based Learning/methods , Students, Dental/psychology , Technology, Dental/education , American Dental Association , Curriculum , Dental Prosthesis , Dental Prosthesis Design , Dental Technicians/education , Histology/education , Humans , Learning , Mouth/anatomy & histology , United States
20.
Oral Health Prev Dent ; 14(5): 403-411, 2016.
Article in English | MEDLINE | ID: mdl-27351736

ABSTRACT

PURPOSE: To evaluate the knowledge of signs, symptoms and risk factors associated with oral cancer amongst undergraduate dental students and members of the general public. MATERIALS AND METHODS: This study was open for a period of six months (Jan-June, 2013) to all undergraduate dental students in the 4th and 5th year of the dental science programme and dental patients attending the School of Dentistry, Griffith University, Australia. The survey evaluated the knowledge and awareness of clinical signs and symptoms and risk factors of oral cancers. RESULTS: A total of 100 undergraduate students and 150 patients provided informed consent and participated in this survey study. Both patients and dental students were aware of the importance of early detection of oral cancer. With the exception of smoking and persistent ulceration, this study indicated that the knowledge about oral cancer, its signs, symptoms and risk factors was limited amongst participants. CONCLUSION: This study highlights the need to raise awareness and knowledge pertaining to oral cancer, not only in the general community but also amongst those in the dental field. Specific points of concern were the common intraoral sites for oral cancer, erythroplakia as a risk factor, the synergistic action of smoking and alcohol, and HPV (human papilloma virus) as risk factors for oral cancer.


Subject(s)
Education, Dental , Health Knowledge, Attitudes, Practice , Mouth Neoplasms , Public Opinion , Students, Dental , Alcohol Drinking/adverse effects , Early Detection of Cancer , Erythroplasia/complications , Health Literacy , Humans , Mouth Neoplasms/diagnosis , Mouth Neoplasms/etiology , Oral Ulcer/complications , Papillomaviridae/physiology , Papillomavirus Infections/virology , Risk Factors , Smoking/adverse effects
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