Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
1.
Biomimetics (Basel) ; 9(6)2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38921228

RESUMO

BACKGROUND AND OBJECTIVES: Two of the most exciting new technologies are biotechnology and nanotechnology. The science of nanostructures, or nanotechnology, is concerned with the development, testing, and use of structures and molecules with nanoscale dimensions ranging from 1 to 100 nm. The development of materials and tools with high specificity that interact directly at the subcellular level is what makes nanotechnology valuable in the medical sciences. At the cellular or tissue level, this might be converted into focused clinical applications with the greatest possible therapeutic benefits and the fewest possible side effects. The purpose of the present study was to review the literature and explore the applicability of the nanostructured materials in the process of the regeneration of the soft and hard tissues of the oral cavity. MATERIALS AND METHODS: An electronic search of articles was conducted in several databases, such as PubMed, Embase, and Web of Science, to conduct this study, and the 183 articles that were discovered were chosen and examined, and only 22 articles met the inclusion criteria in this review. RESULTS: The findings of this study demonstrate that using nanoparticles can improve the mechanical properties, biocompatibility, and osteoinductivity of biomaterials. CONCLUSIONS: Most recently, breakthroughs in tissue engineering and nanotechnology have led to significant advancements in the design and production of bone graft substitutes and hold tremendous promise for the treatment of bone abnormalities. The creation of intelligent nanostructured materials is essential for various applications and therapies, as it allows for the precise and long-term delivery of medication, which yields better results.

2.
Heliyon ; 10(10): e30836, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38803980

RESUMO

Background: Dental cavities are common oral diseases that can lead to pain, discomfort, and eventually, tooth loss. Early detection and treatment of cavities can prevent these negative consequences. We propose CariSeg, an intelligent system composed of four neural networks that result in the detection of cavities in dental X-rays with 99.42% accuracy. Method: The first model of CariSeg, trained using the U-Net architecture, segments the area of interest, the teeth, and crops the radiograph around it. The next component segments the carious lesions and it is an ensemble composed of three architectures: U-Net, Feature Pyramid Network, and DeeplabV3. For tooth identification two merged datasets were used: The Tufts Dental Database consisting of 1000 panoramic radiography images and another dataset of 116 anonymized panoramic X-rays, taken at Noor Medical Imaging Center, Qom. For carious lesion segmentation, a dataset consisting of 150 panoramic X-ray images was acquired from the Department of Oral and Maxillofacial Surgery and Radiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca. Results: The experiments demonstrate that our approach results in 99.42% accuracy and a mean 68.2% Dice coefficient. Conclusions: AI helps in detecting carious lesions by analyzing dental X-rays and identifying cavities that might be missed by human observers, leading to earlier detection and treatment of cavities and resulting in better oral health outcomes.

3.
Exp Ther Med ; 25(1): 28, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36561612

RESUMO

Temporomandibular disorders (TMDs) are characterized by numerous pain manifestations. Their treatment often involves the use of an oral splint. Recent research has found a relationship between migraines, nociceptive pain and TMDs. The aim of the present study was to perform a scoping review of studies in order to evaluate the effectiveness of the various types of oral splint in the treatment of migraine or nociceptive pain. Publications were retrieved from seven databases (PubMed, Web of Science, EMBASE, Scopus, ProQuest, SpringerLink and Ovid). Out of the 15 included publications, three studies were before and after studies, with no control group, whereas the other twelve studies were clinical trials, among which two publications were crossover studies. A clear, single distinction of pain was difficult to describe. Therefore, numerous publications focused on a combination of various types of pains, including myofascial, temporomandibular joint, headaches and migraine-like symptoms, all of which mimicked TMD pain. Overall, six studies used the stabilization splint (SS), three explored the comparison between the SS and the nociceptive trigeminal inhibition splint (NTIS) and two the NTIS. The majority of publications reported a positive outcome of splint therapy. Regarding the type of oral splint usage, the most commonly used one was the SS, followed by the NTIS. The definition and assessment of pain were heterogenous in the identified articles. The findings of the current study showed that occlusal splints may help with pain management, and that effective treatment of TMD-related pain at an early stage can enhance the quality of life of patients.

4.
Medicines (Basel) ; 9(12)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36547996

RESUMO

Background: This study aimed at identifying errors encountered in orthopantomography (OPG) in post-traumatic patients caused by limitations in performing a correct technique. Methods: A retrospective observational study was performed. Diagnosis, exposure/processing mistakes, positioning-related errors, and bimaxillary immobilization were evaluated. Results: Thirty panoramic radiographs with mandible fractures were examined. Twelve error types were encountered: errors in exposure or processing, air radiolucency in the palatoglossal space, errors in the alignment of the Frankfort horizontal plane: head in flexion, with a joyful expression or head extended, with a somber appearance, errors towards the mid-sagittal plane (lateral head inclination, deviation, or rotation), errors caused by the non-use of the bite-block or inappropriate position on the device, errors caused by positioning outside the focal plane, artifacts/shadow images produced by post-operative metal plates, and bimaxillary immobilization errors. The number of errors per radiograph ranged from two to a maximum of five. The most dominant ones were inappropriate alignment in the focal plane and lateral rotation of the head in over 70% of cases. Lateral deviation and palatoglossal air were present in more than 50% of images. Conclusions: In trauma cases, technical difficulties in obtaining a proper OPG image are common and often insurmountable, limiting the diagnosis.

5.
Medicina (Kaunas) ; 58(10)2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36295498

RESUMO

Background and Objectives: Vitamin D (Vit. D) is known for its role in the skeletal system. Vit. D deficiency is also widely researched for its effects on the healing of fractures, bone defects, and osseointegration of implants. In the literature, there are studies that investigated the effects of dietary supplementation with Vit. D to reduce Vit. D deficiency, but increasing the serum level of this vitamin takes time. Therefore, an attempt has been made to combat the effect of Vit. D deficiency through topical applications. The aim of this article was to conduct a review of the existing bibliographic data that investigate the effect of Vit. D on bone regeneration. Materials and Methods: In order to carry out this review, an electronic search was made in several databases and the articles found were selected and analyzed. Results: The in vitro studies' results demonstrated that Vit. D has a high therapeutic potential by enhancing the differentiation of stem cells in osteoblasts. Human and animal studies were conducting using various methods, but most of them revealed that Vit. D has a positive influence on the process of bone regeneration. Conclusions: The overall results of the research showed that, indeed, Vit. D is beneficial for bone regeneration; however, most of the studies imply that a thorough research is still needed for finding the most effective mode of administration and the dose needed in order to achieve the desired effect.


Assuntos
Fraturas Ósseas , Deficiência de Vitamina D , Animais , Humanos , Vitamina D/farmacologia , Vitamina D/uso terapêutico , Vitaminas/uso terapêutico , Regeneração Óssea
6.
Artigo em Inglês | MEDLINE | ID: mdl-36078792

RESUMO

The temporomandibular joint disorder (TMD) is a syndrome that affects the masticatory muscles and temporomandibular joint (TMJ). Its pathophysiology is not yet fully known. Cephalometric analysis is used for routine evaluation regarding orthodontic treatment and other purposes. The aim of this study was to assess if using cephalometric analysis and TMJ conservative therapy to evaluate the hyoid bone position and the cervical posture reduced symptoms in adults with TMDs compared to no intervention. The authors conducted a systematic review of the literature (PubMed, Cochrane, Web of Science, Scopus, and Embase) for clinical studies of TMDs with conservative treatment and lateral cephalometric analysis of the hyoid and cervical posture. To assess the risk of bias for non-randomized clinical trials ROBINS-I tool was used. Out of 137 studies found, 6 remained to be included. Most of them found a link between TMD and lateral cephalometric analysis, but there was a high risk of bias. This review found a possible link between TMDs, the neck and cervical posture. There is a benefit reported regarding the use of the lateral cephalometry as a treatment, but more extensive prospective randomized clinical trials are necessary to be able to draw definitive conclusions.


Assuntos
Osso Hioide , Transtornos da Articulação Temporomandibular , Adulto , Cefalometria , Humanos , Osso Hioide/diagnóstico por imagem , Postura/fisiologia , Estudos Prospectivos , Transtornos da Articulação Temporomandibular/diagnóstico por imagem
7.
Dent J (Basel) ; 10(2)2022 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-35200248

RESUMO

Introduction: Assessment of maxillary transverse discrepancy requires an accurate tool in order to implement the appropriate treatment plan. Aim: To evaluate the accuracy of Pont's Index in confirming a transverse maxillary deficiency by comparing its results with the corresponding results yielded by the University of Pennsylvania CBCT analysis. Material and methods: The study was performed on dental casts and CBCT's of 60 randomly selected patients by adopting a cluster sampling method. The results of Pont's Index and University of Pennsylvania CBCT analysis were analyzed through McNemar's test using Excel Data Analysis, and the accuracy indicators for Pont's Index were computed using MedCalc Ltd. Results: Mc Nemar's test revealed a p-value of 0.85. The accuracy indicators of Pont's Index were: sensitivity: 69%; specificity: 16.6%; positive predictive value: 65%; negative predictive value: 18.75%; positive likelihood ratio: 0.83; negative likelihood ratio: 1.86; and accuracy: 53.28%. Conclusion: Due to the fact that CBCT is not used on a daily basis and Pont's Index has a relatively high sensitivity (69%) making it suitable to detect patients with a narrow maxilla, assessment of the maxillary deficiency on CBCT can be recommended for cases were the midpalatal suture maturation should be evaluated.

8.
Bosn J Basic Med Sci ; 22(1): 22-38, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34255618

RESUMO

Perineural spread (PNS) represents the tumor's ability to disseminate along nerves. The aim of this article is to review the relevant literature about the PNS in head and neck tumors (HN). The important information for imaging analysis is summarized in a diagnostic flow-chart. The pathogenesis, clinical signs, prognostic importance, and technical considerations for computer tomography and magnetic resonance imaging are briefly discussed. The anatomical pathways of the cranial nerves (CNs) and the main check-points are synthesized. Most commonly affected nerves are the trigeminal and facial, although any of the CNs may be involved. The described imaging features represent important clues for an optimal differential diagnosis. PNS worsens the prognosis and significantly changes the treatment, thus radiologists should be aware of this entity and be able to find it on imaging in the appropriate clinical context.


Assuntos
Neoplasias dos Nervos Cranianos , Neoplasias de Cabeça e Pescoço , Neoplasias dos Nervos Cranianos/diagnóstico por imagem , Neoplasias dos Nervos Cranianos/patologia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Invasividade Neoplásica , Tomografia Computadorizada por Raios X
9.
J Med Life ; 14(2): 181-197, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34104241

RESUMO

The present study investigated the capacity of Suprathel® (a copolymer membrane, so far validated for skin regeneration) to also regenerate oral tissue - mucosa and bone, by comparing this biomaterial, in a split-mouth rabbit model, to Mucoderm®, a xenogeneic collagen matrix certified for keratinized oral mucosa healing. The clinical reason behind this experimental animal model was to determine whether the benefits of this advanced skin regeneration product (Suprathel®) could be conveyed for future evaluation in clinical trials of oral tissue regeneration in humans. The outcomes of this study validated the use of Suprathel®, a terpolymer of polylactide with trimethylene carbonate and ε-caprolactone, for stimulation of oral epithelium and alveolar bone regeneration in rabbits. Both Suprathel® and Mucoderm® exhibited comparable results and the null hypothesis stating a comparable regenerating effect of these two materials could not be rejected.


Assuntos
Osso e Ossos/patologia , Epitélio/patologia , Boca/fisiologia , Poliésteres/química , Regeneração , Cicatrização , Animais , Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Osso Esponjoso/patologia , Regeneração Tecidual Guiada , Masculino , Mucosa Bucal/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Coelhos , Cicatrização/efeitos dos fármacos
10.
Maxillofac Plast Reconstr Surg ; 43(1): 19, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34191144

RESUMO

BACKGROUND: MicroRNAs (miRs) are small, non-coding mRNA molecules which regulate cellular processes in tumorigenesis. miRs were discovered in extracellular environment and biological fluids, carrying marks of head and neck squamous cell carcinoma (HNSCC). They were also identified in abundance in salivary exosomes, in which they are protected by exosome lipid barrier against enzymatic injuries and therefore, the accuracy of exosomal miR-based cancer detection increase. This systematic review aimed to reveal and inventorize the most reliable exosomal miRNAs in saliva samples which can be used as novel biomarkers for early detection of HNSCC. MATERIALS AND METHODS: A systematic literature search, according to PRISMA guideline, was performed on Pubmed and Google Academic libraries, based on specific keywords. Original articles published between 2010 and 2021 were selected. The quality of each paper was assessed using the Quality Evaluation Scoring Tool. RESULTS: At the end of selection process, five studies met the inclusion criteria. These studies analyzed twelve salivary exosomal miRs, presenting different methods of exosome and miR identification for HNSCC detection. A comprehensive explanation of the miR pathways of action was drawn and illustrated in this review. CONCLUSION: Exosomal miRs are promising biomarkers for oral cavity and oropharyngeal cancer detection. miR-10b-5p, miR-486-5p, miR-24-3p and miR-200a stand as the most useful ones in saliva sample examination.

11.
Oral Radiol ; 37(4): 625-630, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33420944

RESUMO

OBJECTIVES: The aim of the study is to evaluate the ultrasonographic dimensional changes of the anterior belly of the digastric muscle (ABDM), occurring after intramuscular botulinum toxin A (BTX-A) injection during orthognathic surgery, in a series of five Class II malocclusion patients. METHODS: All the patients received 20 units of BTX-A, into both ABDM, intraoperatively. The length, width and cross-sectional area (CSA) of the ABDM were ultrasonographically measured at three different time points: T0 (preoperatively), T1 (postoperatively at 2 weeks after the surgical intervention), and T2 (postoperatively at 6-9 months). RESULTS: A statistically significant higher length of the ABDM was noted postoperatively, at T1 and T2 compared to T0. The patients showed an increased length by 12.2% at 2 weeks postoperatively and continued to increase, reaching 24.6% at 6 months. A decreased width of ABDM by 6.5% at T1 compared with T0 was also found. CONCLUSIONS: Postoperative ultrasound (US) follow-up measurements in patients with Class II malocclusion, orthognathic surgery and intraoperative BTX-A injection in the ABDM, showed dimensional changes of the muscle, with elongation and thinning. The muscular modifications were more pronounced at 6 months postoperatively, indicating consistency and potential benefit of using BTX-A in reducing the risk of surgical relapse. Further data on longer-term follow-up and larger number of cases are necessary.


Assuntos
Toxinas Botulínicas Tipo A , Má Oclusão Classe II de Angle , Cirurgia Ortognática , Humanos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/cirurgia , Músculos , Ultrassonografia
12.
Maedica (Bucur) ; 15(2): 258-265, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32952693

RESUMO

Objectives: To review the main clinical, radiological and treatment aspects of patients with post-traumatic bifid mandibular condyles (BMC), to report a new case of BMC in a patient with history of trauma and to discuss the long term adaptive changes of the opposite condylar head. Methods: An electronic search in major medical databases was accomplished. Case series and case reports, prospective or retrospective cohort studies of patients with characteristics of traumatic BMC were included. Extracted data included demographic variables, clinical aspects, imagining examinations and treatment methods performed. Results: The systematic review included 60 patients with 72 post-traumatic BMC. The unilateral involvement (73.3%) and mediolateral condylar orientation (75%) were the most common types of post-traumatic BMC described. Most of the patients were symptomatic, with ankylosis (60%), limitation in mandibular movements (55%) and facial asymmetry (41.6%) being the most common clinical signs. Conclusion: The presence of the post-traumatic BMC is accompanied by important clinical signs, a correct and an early evaluation being essential for an optimal treatment.

13.
Med Pharm Rep ; 93(2): 200-209, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32478328

RESUMO

BACKGROUND AND AIMS: Considering nowadays trend among dentists to install a radiology laboratory beside their current practice, we proposed to investigate the aspect of financial efficiency related to such investment. METHODS: We evaluate two existing options: simple investment, consisting of intra-oral equipment and accessories, or investment in a radiology center that includes panoramic and CBCT equipment. The initial investment includes equipment acquisition, fitting out of the location, radiology accreditation and other miscellaneous expenses. Costs were estimated based on current quotations on the specific market available in Romania. We also described a financial model to estimate the financial risk. RESULTS: The analysis was made under the assumptions that the laboratory is operated by the dentist who made the investment in the form of a legal person and paying corporate tax like all Romanian entities. The analysis took into account current fees for different types of X-rays, usual expenses of such a laboratory, and describes the approach to this analysis, starting with the initial investment estimation and forecast of revenues and expenses. Based on these projections and assessment of the working capital, we have built the cash flows forecast. Following a risk analysis we could assess the financial efficiency of the two investment alternatives. CONCLUSIONS: Our study reveals that the radiology center represents a more profitable investment due to the higher economic return rate.

14.
Sci Rep ; 10(1): 2113, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034200

RESUMO

Assessing the possible biological effects of exposure to low doses of ionizing radiation (IR) is one of the prime challenges in radiation protection, especially in medical imaging. Today, radiobiological data on cone beam CT (CBCT) related biological effects are scarce. In children and adults, the induction of DNA double strand breaks (DSBs) in buccal mucosa cells and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and antioxidant capacity in saliva samples after CBCT examination were examined. No DNA DSBs induction was observed in children nor adults. In children only, an increase in 8-oxo-dG levels was observed 30 minutes after CBCT. At the same time an increase in antioxidant capacity was observed in children, whereas a decrease was observed in adults. Our data indicate that children and adults react differently to IR doses associated with CBCT. Fully understanding these differences could lead to an optimal use of CBCT in different age categories as well as improved radiation protection guidelines.


Assuntos
Tomografia Computadorizada de Feixe Cônico/efeitos adversos , Quebras de DNA de Cadeia Dupla/efeitos da radiação , DNA/efeitos da radiação , Oxirredução/efeitos da radiação , Tomografia Computadorizada de Feixe Cônico Espiral/efeitos adversos , Adulto , Criança , Feminino , Humanos , Masculino , Mucosa Bucal/efeitos da radiação , Estudos Prospectivos , Proteção Radiológica , Radiação Ionizante
15.
Maedica (Bucur) ; 14(3): 213-219, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31798735

RESUMO

Objectives:The aim of this CBCT study was to evaluate the postoperative volume changes of the rhinosinusal airway space, maxillary sinuses and nasal fossa, that occur after Le Fort I osteotomy, using individual segmentation of 3D virtual models. Material and methods:A number of 16 patients (with Class II and Class III malocclusions) who underwent a CBCT examination for orthognathic surgery at six month-interval between preoperative and postoperative evaluations were included. Patients with thickening of the sinus mucosa, craniofacial syndromes, maxillofacial trauma, rhinoplasty or other maxillofacial pathological conditions were excluded from the study. Individual segmentation of airway volumes was performed by the ITK-SNAP 2.0 software. Paired student t-test was used for the statistical examination of volume changes and Pearson's test for the assessment of intra-rate correlation. Outcomes:A statistically significant decrease in the rhinosinusal volume in Class II (9.36±3.43 cm3) and Class III malocclusions (3.65±2.96 cm3) was found after Le Fort I osteotomy. A decrease in volume was also found for maxillary sinuses (5.63±1.52 cm3 for Class II and 6.72±4.5 cm3 for Class III malocclusion). Nasal fossa decreased in volume (3.79±3.8 cm3) in Class II malocclusion patients and increased (3.07±2.39 cm3) in Class III malocclusion patients. The Pearson correlation revealed a high intra-rate agreement of measurements. Conclusion:Le Fort I osteotomy modifies the postoperative volume of rhinosinusal aerial spaces and individual segmentation on CBCT images is a useful tool to analyze the changes.

16.
Med Pharm Rep ; 92(4): 346-351, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31750433

RESUMO

Cone beam computed tomography can be used in pediatric population when a tridimensional analysis of dental and maxillofacial bone structures is required. Even though CBCT is considered a low dose radiological examination, ionizing radiation is a known human carcinogenic factor. Furthermore, biological effects are more important in young patients because of their higher radiosensitivity. Orthodontic treatment is typically initiated at young ages and the most common radiographs at this age are dental. This makes it important to quantify the effects of diagnostic radiographs, in particular of CBCT, due to the fact that the radiation doses are higher compared to conventional radiological methods. So far, the carcinogenic response after low dose radiation exposure is not fully understood in the scientific literature. The aim of our review was to emphasize the main indications of CBCT in orthodontics and to evaluate the radiation doses and potential risks of CBCT irradiation of pediatric patients.

17.
Clin Oral Investig ; 23(9): 3437-3444, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31352516

RESUMO

OBJECTIVES: The aim of the present study is to evaluate the early and long-term postoperative dimensional changes of the muscles of the mandible in patients with orthognathic surgery for class II and class III malocclusions by using ultrasonography (US). MATERIAL AND METHODS: Twenty-six patients who underwent bimaxillary orthognathic surgery for class II or class III malocclusions (14 and 12 patients, respectively) were ultrasonographically examined. The length, width, and cross-sectional area of the masseter and suprahyoid muscles were measured at three different time points: T0 (preoperatively), T1 (early postoperatively at 1 month after the surgery), and T2 (late postoperatively at 9 months). A repeated measures ANOVA was used to calculate statistically significant dimensional changes of the mandibular muscles. RESULTS: Statistically significant dimensional changes were found postoperatively in class II malocclusion patients only. The digastric muscle showed higher values for the length and lower values for the width (p < .05) at T1. The geniohyoid muscles were higher in length at T1 and lower in cross-sectional area (CSA) (p < .05) at T2. A decreased measured length and an increased measured width were found in case of the mylohyoid muscle (p < .05) at T2. The early and long-term postoperative dimensional changes of the masseter muscle were not statistically significant. CONCLUSIONS: The mandibular muscles showed a variable adaptive response to the orthognathic surgery. US should be considered for the long-term follow-up of muscular dimensional changes in class II malocclusion patients. CLINICAL RELEVANCE: From a clinical perspective, US is a reliable, non-invasive, and widely available method, which allows monitoring the postoperative muscular changes occurring in class II malocclusion patients.


Assuntos
Má Oclusão Classe III de Angle , Má Oclusão Classe II de Angle , Músculo Esquelético , Procedimentos Cirúrgicos Ortognáticos , Cefalometria , Seguimentos , Humanos , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/cirurgia , Má Oclusão Classe III de Angle/diagnóstico por imagem , Má Oclusão Classe III de Angle/cirurgia , Mandíbula/cirurgia , Maxila , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Osteotomia de Le Fort
18.
Drug Metab Rev ; 51(4): 570-588, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296117

RESUMO

This review intended to comparatively explain and present the most important medical use and biological impact of poly-lactides and lactide-based composites. The utilization and degradation of compounds based on lactic acid and polylactides is described in detail. Understanding the metabolism and degradation phenomenon and the factors that potentially influence it is key to modulating their properties as well as their characteristics driven from the fabrication procedures and the fields of use. All these are commented according to the clinician's criteria. The current debate on the advantages and shortcomings of various resorbable polymeric materials categories is also analyzed, from the perspective of the users of resorbable polylactide-based biomaterials. The scientific literature comprises either distinct chemical and physical or specific animal or medical description of resorbable materials; so that in compensation, the present review covers all topics for the most appropriate comprehensive update of the reader.


Assuntos
Implantes Absorvíveis , Poliésteres/administração & dosagem , Poliésteres/química , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo , Humanos , Ácido Láctico/química , Poliésteres/metabolismo
19.
Dentomaxillofac Radiol ; 48(6): 20180428, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30912976

RESUMO

OBJECTIVES: Cone-beam CT (CBCT) is a medical imaging technique used in dental medicine. However, there are no conclusive data available indicating that exposure to X-ray doses used by CBCT are harmless. We aim, for the first time, to characterize the potential age-dependent cellular and subcellular effects related to exposure to CBCT imaging. Current objective is to describe and validate the protocol for characterization of cellular and subcellular changes after diagnostic CBCT. METHODS: Development and validation of a dedicated two-part protocol: 1) assessing DNA double strand breaks (DSBs) in buccal mucosal (BM) cells and 2) oxidative stress measurements in saliva samples. BM cells and saliva samples are collected prior to and 0.5 h after CBCT examination. BM cells are also collected 24 h after CBCT examination. DNA DSBs are monitored in BM cells via immunocytochemical staining for γH2AX and 53BP1. 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) and total antioxidant capacity are measured in saliva to assess oxidative damage. RESULTS: Validation experiments show that sufficient BM cells are collected (97.1 ± 1.4 %) and that γH2AX/53BP1 foci can be detected before and after CBCT examination. Collection and analysis of saliva samples, either sham exposed or exposed to IR, show that changes in 8-oxo-dG and total antioxidant capacity can be detected in saliva samples after CBCT examination. CONCLUSION: The DIMITRA Research Group presents a two-part protocol to analyze potential age-related biological differences following CBCT examinations. This protocol was validated for collecting BM cells and saliva and for analyzing these samples for DNA DSBs and oxidative stress markers, respectively.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Mucosa Bucal , Saliva , Tomografia Computadorizada de Feixe Cônico Espiral , Feminino , Humanos , Masculino , Mucosa Bucal/citologia , Raios X
20.
Dentomaxillofac Radiol ; 48(1): 20170462, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30168750

RESUMO

OBJECTIVES: Cone-beam CT (CBCT), a radiographic tool for diagnosis, treatment, and follow-up in dental practice, was introduced also in pediatric radiology, especially orthodontics. Such patients subjected to repetitive X-rays examinations may receive substantial levels of radiation doses. Ionizing radiation (IR), a recognized carcinogenic factor causing DNA double-strand breaks (DSBs) could be harmful to undifferentiated cells such as dental pulp stem cells (DPSCs) since inaccurately repaired or unrepaired DSBs may lead to malignant transformation. The H2AX and MRE11 proteins generated following DSBs formation and pro-inflammatory cytokines (CKs) secreted after irradiation are relevant candidates to monitor the cellular responses induced by CBCT. METHODS: DPSCs were extracted from human exfoliated deciduous teeth and their phenotype was assessed by immunocytochemistry and flow-cytometry. Cells were exposed to IR doses: 5.4-107.7 mGy, corresponding to 0.5-8 consecutive skull exposures, respectively. H2AX and MRE11 were detected in whole cells, while IL-1α, IL-6, IL-8, TNFα in supernatants, using enzyme-linked immunosorbent assay (ELISA) at different time points after exposure. RESULTS: The phosphorylation level of H2AX in DPSCs increased considerably at 0.5 h after exposure (p < 0.001 for 3, 5, 8 skull exposures and p < 0.05 for 1 skull exposure, respectively). MRE11 response could only be detected for the highest IR dose (p < 0.001) in the same interval. CKs secretion increased upon CBCT exposure according to doses and time. CONCLUSIONS: The DPSCs exposure to CBCT induces transient DNA damage and persistent inflammatory reaction in DPSCs drawing the attention on the potential risks of IR exposures and on the importance of dose monitoring in pediatric population.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Dano ao DNA , Células-Tronco , Dente Decíduo , Criança , Tomografia Computadorizada de Feixe Cônico/efeitos adversos , Humanos , Inflamação , Fosforilação , Células-Tronco/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...