Hasil untuk "Dentistry"

J. Geng, K. Tan, Guihong Liu

N. Olea, R. Pulgar, P. Perez et al.

We tested some resin-based composites used in dentistry for their estrogenic activity. A sealant based on bisphenol-A diglycidylether methacrylate (bis-GMA) increased cell yields, progesterone receptor expression, and pS2 secretion in human estrogen-target, serum-sensitive MCF7 breast cancer cells. Estrogenicity was due to bisphenol-A and bisphenol-A dimethacrylate, monomers found in the base paste of the dental sealant and identified by mass spectrometry. Samples of saliva from 18 subjects treated with 50 mg of a bis-GMA-based sealant applied on their molars were collected 1 hr before and after treatment. Bisphenol-A (range 90-931 micrograms) was identified only in saliva collected during a 1-hr period after treatment. The use of bis-GMA-based resins in dentistry, and particularly the use of sealants in children, appears to contribute to human exposure to xenoestrogens. ImagesFigure 1. AFigure 1. BFigure 2.Figure 3. AFigure 3. BFigure 4. AFigure 4. BFigure 5. AFigure 5. BFigure 6. AFigure 6. BFigure 7. AFigure 7. BFigure 8.Figure 9.Figure 10.

F. Beuer, J. Schweiger, D. Edelhoff

A. Peutzfeldt

K. Konopka, T. Gośliński

E. J. S. J. D. Ms, Harald O. Heymann Dds MEd, Andreeva Ms

Feel lonely? What about reading books? Book is one of the greatest friends to accompany while in your lonely time. When you have no friends and activities somewhere and sometimes, reading book can be a great choice. This is not only for spending the time, it will increase the knowledge. Of course the b=benefits to take will relate to what kind of book that you are reading. And now, we will concern you to try reading sturdevants art and science of operative dentistry as one of the reading material to finish quickly.

C. Lung, J. Matinlinna

Isabelle Denry, J. R. Kelly

André Guaraci DeVito-Moraes, Isabela Souza Vardasca, Miguel Peñarrocha-Diago et al.

This study investigates the mechanical and optical properties of monolithic zirconia used in dentistry, focusing on how different concentrations of yttrium oxide and varied sintering times affect the material. A critical trade-off in ceramics has been reported in the literature, in which increased crystalline content (like in zirconia) leads to higher mechanical strength but lower aesthetic translucency. However, detailed information on this trade-off process for different types of zirconia is lacking. A total of seven types of zirconia varying in yttria content (3 mol% to 5 mol%) were tested across four sintering protocols available in a laboratory zirconia sintering device: Slow (12 h), Standard (8 h), Fast (3.5 h), and Ultrafast (1.15 h). The primary findings indicate that while a higher yttria concentration correlates with lower flexural strength and high translucency, the sintering time generally did not compromise mechanical strength or color variation across most samples. Nevertheless, the Fast and Ultrafast protocols did significantly reduce the translucency of zirconia with a high concentration of yttrium oxide.

Yuto Takada, Hiroshi Doi, Yuko Kinoshita et al.

A case of a patient who developed a radiation recall reaction (RRR) triggered by coronavirus disease 2019 (COVID-19) infection following surgery and chemoradiotherapy for carcinoma of the buccal mucosa is reported. A 75-year-old woman presented in October 2023 with pyrexia and erythema extending from the left cheek to the anterior chest area. In December 2021, she had undergone surgery to remove a carcinoma of the left buccal mucosa (pT2N0M0), followed by left comprehensive neck dissection for delayed cervical lymph node metastasis in June 2022, with subsequent adjuvant chemoradiotherapy. Her course was uneventful until September 2023, when she developed COVID-19. Twenty-three days after COVID-19 infection had been confirmed, she developed systemic pyrexia with erythema and a heat sensation from her left cheek to the left anterior chest. On presentation, her temperature was 39 ºC, and she had a mild sore throat. Erythema and a heat sensation were apparent from the left cheek to the neck and anterior chest, corresponding to the previously irradiated area. Laboratory tests showed a white blood cell count of 11,760/μl, and C-reactive protein of 16.0 mg/dl. Computed tomography did not show any obvious abscess formation or infection source. An RRR was diagnosed, and she was admitted for treatment with intravenous sulbactam/ampicillin and intravenous hydrocortisone sodium succinate. Five days after admission, the inflammatory reaction had improved, and she was discharged. Her subsequent course has been uneventful, with no flareup of the RRR. This case is presented along with a review of relevant literature.

Gokhan Canko, Ozge Doganay Ozyilmaz

Abstract Statement of problem Recent advancements in digital technology have revolutionized implant dentistry, particularly with additively manufactured subperiosteal jaw implants (AMSJIs). These implants allow patient-specific designs that adapt to anatomical requirements. However, optimizing stress distribution remains a challenge. Purpose This study evaluated the stress distribution in AMSJIs and surrounding bone by analyzing different framework materials (PEEK and Co-Cr), anterior wing designs (I- and Y-shaped), and cantilever extensions using three-dimensional finite element analysis. Methods A model was created from a patient with an atrophic, edentulous maxilla. Biomechanical evaluation of eight maxillary implant scenarios was performed under a 200 N force applied at a 45° oblique angle. Stress distribution in the bone, implants, screws, and prosthetic frameworks, as well as prosthetic displacement, was analyzed. Results The lowest implant stress (444.5 MPa) was observed in the Co-Cr group without a cantilever using an I-shaped design, whereas the highest stress (623.0 MPa) occurred in the Co-Cr group with a cantilever using a Y-shaped design. Prosthetic displacement was greater in cantilevered groups, with PEEK exhibiting more displacement than Co-Cr. Conclusions The optimal stress distribution was achieved with the I-shaped design without a cantilever, using Co-Cr. Stress levels were significantly influenced by framework material, wing design, and cantilever presence, underscoring the importance of design and material selection. Clinical significance While stress remained within physiological limits in all cases, avoiding cantilevers and selecting a rigid material can optimize Y-shaped designs. PEEK demonstrated favorable properties in cantilevered designs, but its long-term effects on soft tissue and implants warrant further clinical trials.

S. M. Balaji

Muhammad Zubair Ahmad

Objectives. Rotary single-file endodontic systems are commonly used for root canal treatment. However, very few studies have evaluated the apical extrusion of debris generated by these systems during canal preparation at normal body temperature in laboratory conditions. The aim of this study was to evaluate the amount of apically extruded debris caused by seven different single-file endodontic instrumentation systems at body temperature in mandibular molar teeth with curved root canals. Methods. One hundred forty mandibular first permanent molars were randomly divided into seven groups (n = 20) to be prepared by one of the following systems at 35°C: Reciproc Blue (REC Blue), WaveOne Gold (WOG), One Reci (OR), Neoniti, HyFlex EDM (HEDM), One Curve (OC), or XP Shaper (XPS). Debris was collected into preweighted Eppendorf tubes. The weight of the extruded debris was recorded by subtracting the weight of the tooth-free apparatus from the post-procedure weight. Data were analyzed by one-way ANOVA and Tukey’s tests (p <5%). Results. REC Blue, WOG, and OR groups extruded significantly more debris from the apex than XPS, OC, and Neoniti groups (p <0.05). No significant difference was observed among the XPS, OC, Neoniti, and HEDM groups (p >0.05). Conclusion. All the instruments were associated with debris extrusion. However, REC Blue, WOG, and OR extrude significantly more debris than other instruments. The amount of debris with different files was REC Blue > OR > WOG > HEDM > OC > Neoniti > XPS. XPS, Neoniti, and OC caused significantly less extrusion of debris than REC Blue, WOG, and OR.

Dandan Wang, Yaru Guo, Boon Chin Heng et al.

Abstract Bone tissue renewal can be enhanced through co-transplantation of bone mesenchymal stem cells (BMSCs) and vascular endothelial cells (ECs). However, there are apparent limitations in stem cell-based therapy which hinder its clinic translation. Hence, we investigated the potential of alternative stem cell substitutes for facilitating bone regeneration. In this study, we successfully prepared cell membrane vesicles (CMVs) from BMSCs and ECs. The results showed that BMSC-derived cell membrane vesicles (BMSC-CMVs) possessed membrane receptors involved in juxtacrine signaling and growth factors derived from their parental cells. EC-derived cell membrane vesicles (EC-CMVs) also contained BMP2 and VEGF derived from their parental cells. BMSC-CMVs enhanced tube formation and migration ability of hUVECs, while EC-CMVs promoted the osteogenic differentiation of hBMSCs in vitro. Using a rat skull defect model, we found that co-transplantation of BMSC-CMVs and EC-CMVs could stimulate angiogenesis and bone formation in vivo. Therefore, our research might provide an innovative and feasible approach for cell-free therapy in bone tissue regeneration.

Abdelfattah Amari, Ahmad Ismael Saber, Haitham Osman et al.

Abstract Water pollution is a pressing global concern, with per- and polyfluoroalkyl substances (PFAS) being considered as “forever contaminants.” Among them, perfluorooctanesulfonic acid (PFOS) has received significant attention for its adverse effects on human health and aquatic ecosystems. This study aimed to design an innovative adsorbent for effective PFOS removal with exceptional water stability, improving its cost-performance trade-off. The current work simultaneously improved the stability of water of Cu-based metal–organic framework (CMOF) and increased its PFOS removal capacity by modifying it with amine-functionalized SiO2 nanoparticles (AF-CMOF). AF-CMOF presented a lower specific surface area of 999 m2 g−1 compared to CMOF with a surface area of 1098 m2 g−1. AF-CMOF showed remarkable PFOS uptake performance of 670 mg/g compared to the performance of the Cu-based MOF which exhibited a PFOS uptake capacity of only 22 mg/g. The most suitable pH for PFOS removal using both adsorbents was determined to be 3. In addition, AF-CMOF demonstrated excellent water stability, retaining its structural integrity even after seven days of water contact, while CMOF structure collapsed rapidly after four days of water exposure. Moreover, the study identified the significant pH influence on the PFOS uptake process, with electrostatic interactions between protonated amine functionalities and PFOS molecules identified as the dominant mechanism. The study’s findings present the potential of synthesized adsorbent as a superior candidate for PFOS uptake and contribute to the development of effective water treatment technologies.

Maryam Alsadat Hashemipour, Parsa Behnam, Fatemeh Ghasemzadeh

Background: The present work deals with examine the awareness and attitudes of specialists of oral diseases, pathology and maxillofacial surgery in 2022 in oral exfoliative cytology.Methods: This study was an analytical and cross-sectional research. The statistical population of the present study was Iranian oral diseases specialists, pathologists and maxillofacial surgeons. A researcher-made questionnaire was given to the specialists by senior student and then they were asked to complete it . The questionnaire was given to people by the final year student. The obtained results were analyzed using the T-test, Chi-Square and SPSS-18 Software. The significance level in data analysis was considered by P <0.05 level.Results: A total of 210 questionnaires were distributed in the study, of which 192 were examined (Response Rate = 91.4%). The study revealed that only 18 participants used exfoliative cytology technique. Moreover, 62% of people had a positive attitude towards the application and performance of cytology. There was a significant relationship between the positive attitude, field of study, graduation year and age. The mean scores of awareness in men and women were 32.38 ± 4.21 and 34.42 ± 3.89 , respectively. The participants had a high level of awareness and attitude towards this technique.Additionally, the mean score of awareness in oral specialists, surgeons and pathologists was 33.12±4.23, 33.65±5.12 and 33.45±5.34, respectively. The study revealed no significant relationship between awareness score, field of study and gender. Nonetheless, there was a significant relationship between graduation year, age and awareness score.Conclusion: The study revealed that only 9.4 percent of participants used exfoliative cytology technique. However, they had a high level of awareness and attitude towards this technique.Keywords: Awareness, Attitude, Exfoliative Cytology, Dentistry

N. Shah, N. Bansal, A. Logani

Dentistry has witnessed tremendous advances in all its branches over the past three decades. With these advances, the need for more precise diagnostic tools, specially imaging methods, have become mandatory. From the simple intra-oral periapical X-rays, advanced imaging techniques like computed tomography, cone beam computed tomography, magnetic resonance imaging and ultrasound have also found place in modern dentistry. Changing from analogue to digital radiography has not only made the process simpler and faster but also made image storage, manipulation (brightness/contrast, image cropping, etc.) and retrieval easier. The three-dimensional imaging has made the complex cranio-facial structures more accessible for examination and early and accurate diagnosis of deep seated lesions. This paper is to review current advances in imaging technology and their uses in different disciplines of dentistry.

Ameet Vaman Revankar, Sagar S Bhat, Joe E Rozario

OBJECTIVES: The study aimed to compare the effects of quadhelix and nickel-titanium (NiTi) expander appliances on lower facial height, to quantify, and evaluate dentoalveolar and orthopedic changes in transverse plane, respectively, to estimate the difference in changes between these two appliances. MATERIALS AND METHODS: Twenty patients, ten for the quadhelix and NiTi expander in the two-appliance group, respectively, participated in this study. A total of 8 readings, 1 for clinical facial height, 2 for model analysis, and 5 for posteroanterior cephalometric analysis were recorded. The statistical tests used were, Student's unpaired and paired t-tests. RESULTS: Both appliances individually, produced statistically highly significant (p < 0.01) expansion every month in both premolar and molar areas with more uniform expansion for quadhelix and less expansion in NiTi palatal expander in the premolar region initially. The skeletal to dental change ratio showed that there was more dental change than skeletal with no inter-appliance differences statistically while assessing the PA cephalometric readings. CONCLUSIONS: This study infers that both appliances are equally efficacious maxillary expanders, which are primarily dentoalveolar and not skeletal (p < 0.05).

Mohammad DN, Ibraheem BF, Khudair HH et al.

Dena Nadhim Mohammad,1 Ban Falih Ibraheem,1 Hassanain Hafidh Khudair,2 Darya Khalid Mahmood1 1Oral Pathology, Oral Diagnosis Department, College of Dentistry, University of Sulaimani, Sulaimani, Iraq; 2General Pathology, Pathology Department, College of Medicine, University of Sulaimani, Sulaimani, IraqCorrespondence: Darya Khalid Mahmood, Tel +9647701934628, Email darya.mahmood@univsul.edu.iqBackground: Salivary tumors have various morphological features and might share some histopathological findings. They are considered a problematic area in diagnosis due to complex clinicopathological features and different biological behavior.Objective: To identify the pathological behavior of salivary tumors immunohistochemically.Methodology: This retrospective study involved thirty formalin-fixed paraffin-embedded blocks of salivary gland tumors. These tumors were stained immunohistochemically with syndecan-1 and cyclin D1. Chi-Square test was used to relate immunoscoring, intracellular localization, intensity, and invasion to different salivary tumors. The correlation of these two markers was done by spearman‘s rho test. P-value < 0.05 was considered statistically significant.Results: The mean age of the patients was 48.69 ± 17.7. The parotid gland was the most commonly reported site in benign tumors, and regarding malignant tumors, maxilla was the most prevalent site. Syndecan-1 in benign tumors showed a predominate score 3, most widely detected in pleomorphic adenoma. Malignant salivary tumors showed 89.4% positive expression with a more frequent score 3, most commonly found in adenocystic carcinoma. Cyclin D1 expressed in all benign salivary tumors, with prominent diffuse mixed intracellular localization in pleomorphic adenoma. Malignant tumors revealed an expression of 94.7%. Moderate scoring with mixed intracellular localization was recorded in adenocystic carcinoma, followed by mucoepidermoid carcinoma. There was a significant correlation between the two markers in response to the distribution of immunostaining in different cell compartments.Conclusion: Syndecan-1 and cyclin D1 showed a significant combined role in salivary tumor progression. Interestingly notable ductal-myoepithelial cells affect epithelial morphogenesis, and growth of pleomorphic adenoma was observed. Furthermore, basophilic cells of cribriform adenocystic carcinomas might control the aggressiveness and proliferation rate of these tumors.Keywords: syndecan-1, cyclin D1, pleomorphic adenoma, adenocystic carcinoma

Erlind Pepla, L. K. Besharat, G. Palaia et al.

This study aims to critically summarize the literature about nano-hydroxyapatite. The purpose of this work is to analyze the benefits of using nano-hydroxyapatite in dentistry, especially for its preventive, restorative and regenerative applications. We also provide an overview of new dental materials, still experimental, which contain the nano-hydroxyapatite in its nano-crystalline form. Hydroxyapatite is one of the most studied biomaterials in the medical field for its proven biocompatibility and for being the main constituent of the mineral part of bone and teeth. In terms of restorative and preventive dentistry, nano-hydroxyapatite has significant remineralizing effects on initial enamel lesions, certainly superior to conventional fluoride, and good results on the sensitivity of the teeth. The nano-HA has also been used as an additive material, in order to improve already existing and widely used dental materials, in the restorative field (experimental addition to conventional glass ionomer cements, that has led to significant improvements in their mechanical properties). Because of its unique properties, such as the ability to chemically bond to bone, to not induce toxicity or inflammation and to stimulate bone growth through a direct action on osteoblasts, nano-HA has been widely used in periodontology and in oral and maxillofacial surgery. Its use in oral implantology, however, is a widely used practice established for years, as this substance has excellent osteoinductive capacity and improves bone-to-implant integration.