564,260 research outputs found

    Prevalence and distribution of endodontic treatments and apical periodontitis in an Italian population sample

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    This study was undertaken to investigate for the first time the distribution and prevalence of apical periodontitis and its determinants in an Italian population. A total of 312 participants (191 women, 121 men) received free clinical examination and full-mouth digital X-ray. Data regarding the oral health status of the patients were collected such as the reason for the visit and the incidence of lesions. We examined 8101 teeth, 6.59% of which had been submitted to endodontic treatment and 15.02% of which were lower molars. Lower molars were reported missing more frequently, in detail 16.24%. Moreover 3.89% of the lower molars had developed an apical lesion, whereas only 0.08% of the lower incisors. Periapical lesions were present in 0.29% of not endodontically treated teeth, while in endodontically treated teeth lesions were present in 17.04%. Additionally, 15.65% of the endodontically treated teeth showed incongruous (long or short) seals. A prevalence of women (61.21%) over men (38.78%) was reported indicating that women attend to their oral health more. Endodontic treatment success and failure in over- or under-filled teeth was evaluated with success being verified in 97% of appropriately treated teeth; the success rate decreases in inappropriately treated teeth (by 72.73% in over-filled and 77.71% under-filled teeth). The prevalence of teeth with periapical lesions amounted to 1.35%. Finally, endodontically treated teeth with periapical lesions amounted to 17.04%. Successful treatment can be achieved when disease is intercepted at an early stage while prevention still remains better than cur

    Zebrafish teeth as a model for repetitive epithelial morphogenesis: dynamics of E-cadherin expression

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    Background: The development of teeth is the result of interactions between competent mesenchyme and epithelium, both of which undergo extensive morphogenesis. The importance of cell adhesion molecules in morphogenesis has long been acknowledged but remarkably few studies have focused on the distribution and function of these molecules in tooth development. Results: We analyzed the expression pattern of an important epithelial cadherin, E-cadherin, during the formation of first-generation teeth as well as replacement teeth in the zebrafish, using in situ hybridization and whole mount immunostaining to reveal mRNA expression and protein distribution. E-cadherin was detected in every layer of the enamel organ during the different stages of tooth development, but there were slight differences between first-generation and replacement teeth in the strength and distribution of the signal. The dental papilla, which is derived from the mesenchyme, did not show any expression. Remarkably, the crypts surrounding the functional teeth showed an uneven distribution of E-cadherin throughout the pharyngeal region. Conclusions: The slight differences between E-cadherin expression in zebrafish teeth and developing mouse and human teeth are discussed in the light of fundamental differences in structural and developmental features of the dentition between zebrafish and mammals. Importantly, the uninterrupted expression of E-cadherin indicates that down-regulation of E-cadherin is not required for formation of an epithelial tooth bud. Further research is needed to understand the role of other cell adhesion systems during the development of teeth and the formation of replacement teeth

    Self-locking telescoping manipulator arm

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    A telescoping manipulator arm and pivotable finger assembly are disclosed. The telescoping arm assembly includes a generally T-shaped arm having three outwardly extending fingers guided on grooved roller guides to compensate for environmental variations. The pivotable finger assembly includes four pivoting fingers. Arcuate teeth are formed on the ends of the fingers. A rack having teeth on four sides meshes with each one of the fingers. One surface of the rack includes teeth along its entire surface which mesh with teeth of one of the fingers. The teeth at the remote end of the rack engage teeth of a gear wheel. The wheel includes a worm which meshes with a worn drive shaft of the drive motor providing a ninety degree self-locking drive for locking the fingers in a desired position. A similar drive provides a self-locking drive for positioning the telescoping arm

    Quality of Root Canal Obturation Performed by Senior Undergraduate Dental Students

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    The aim of the present study was to assess the quality of canal obturation performed by undergraduate denal students at Saveetha Dental College and Hospitals, Chennai. Records of 200 endodontically treated teeth from patients who were visited by undergraduate students between month of November 2014 to May 2015. Periapical radiographs of all treated teeth were assessed in terms of canal obturation quality (adequate density and length). Forty-five percent of teeth fulfilled the criteria of an acceptable root canal obturation. Adequate length and density of root filling was found in 89% and 34% of teeth, respectively. There was a significant difference between maxillary and mandibular teeth regarding the length of root canal obturation. A significant difference was observed between molars and other tooth types. The frequency of root canals with an acceptable filling was significantly greater in the anterior teeth compared to premolars or molars. The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal

    Belt for transmitting power from a cogged driving member to a cogged driven member

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    A belt for transmitting power from a cogged driving member to a cogged driven member such as a pair of wheel sprockets is described. The belt has inflexible teeth spaced along the direction of its travel. Each of the teeth has a longitudinal axis transverse to the direction of belt travel. The belt also includes substantially inextensible fasts spaced transversely to the direction of belt travel. The fasts extend in the direction of belt travel adjacent to the teeth and are looped around preselected numbers of the teeth

    Relationship of Nutritional Status with Oral Health Status in Visual Impairment

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    To analyze the relationship of nutritional status with oral health status among visual impairment. The subjects were 146 elderly people (70 males and 76 females) aged 20-72 years (mean 48.8±6.2 years), Phitsanulok, Thailand. Mini Nutritional Assessment (MNA) questionnaires were administered. Oral examinations investigated the number of present teeth, DMFT and Functional Tooth Units (FTUs). According to the MNA score, 44.5% of subjects were categorized as normal nutrition, 47.3% as questionable, and 8.2 % as malnutrition. The mean numbers of present teeth and FTUs were 17.8±6.9 and 6.9±3.2, respectively. Subjects with malnutrition had lower numbers of present teeth (10.7±1.4) and FTUs (4.3±1.7) than those with normal nutrition (20.2±0.7 and 12.3±0.5) (p≤0.05). Nutritional status of visual impaired Thai was associated with mean numbers of present teeth and FTUs. Keeping many natural teeth or having appropriate numbers of FTUs by replacing missing teeth with dentures would prevention malnutrition

    The use of pulse oximetry in evaluation of pulp vitality in immature permanent teeth

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    Background and aim: The current methods of pulp vitality assessment, either electric or thermal, are of limited use in children. Recently, traumatized and immature teeth may not respond to such methods and because such methods require subjective responses, it may not provide accurate results particularly in children. Pulse oximetry, an atraumatic approach, is used to measure oxygen saturation in vascular system. The aim of this study was to investigate the use of pulse oximetry to evaluate pulp vitality status in immature permanent teeth. Methods and materials: The study was conducted on 329 maxillary central and lateral incisors in children. The negative control group consisted of 10 root filled teeth. Systemic oxygen saturation was first measured on the thumb of the individual using a custom-made sensor. Oxygen saturation values of the teeth were then evaluated. The correlation between oxygen saturation measurement obtained from finger and tooth, and the correlation between oxygen saturation values and stage of root development were analyzed. A further comparison was made between the teeth with open and closed apex. Results: Mean oxygen values recorded in the patient's finger were 97.17, and mean oxygen values in the maxillary central and lateral incisors were 86.77 and 83/92, respectively. There was no significant correlation between blood oxygen levels in the finger and in the teeth. (P > 0.05) There was a significant negative correlation between the stage of root development and the blood oxygen levels in the patients' teeth. (P < 0.05) Mean oxygen values in the teeth with open apex were significantly higher than the teeth with closed apex. (P < 0.001). Conclusion: Vital teeth provided consistent oxygen saturation readings, and non-vital teeth recorded no oxygen saturation values. During tooth development, the oxygen saturation values decreased. These findings confirm that the pulse oximetry is capable of detecting the pulpal blood flow and oxygen saturation. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

    Congenital Adrenal Hyperplasia: A Case Report with Premature Teeth Exfoliation and Bone Resorption

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    Congenital adrenal hyperplasia (CAH) is an inherited autosomal recessive disorder characterized by insufficient production of cortisol. The aim of this case report was to present a child with CAH, premature exfoliation of primary teeth and accelerated eruption of his permanent teeth related to bone resorption. A 4.5-year-old Caucasian boy with CAH and long-term administration of glucocorticoids was referred for dental restoration. Clinical examination revealed primary molars with worn stainless steel crowns, severe attrition of the upper canines, and absence of the upper incisors. Before the completion of treatment, abnormal mobility of the first upper primary molars and the lower incisors was detected, and a few days later the teeth exfoliated prematurely. Histologic examination revealed normal tooth structure. Alkaline phosphatase and blood cells values were normal. Eruption of the permanent dentition was also accelerated. Tooth mobility was noticed in the permanent teeth as soon as they erupted, along with bone destruction. Examination revealed an elevated level of receptor activator of nuclear factor-kB ligand and lower-than-normal osteoprotegerin and vitamin D levels. The patient was treated with vitamin D supplements, and his teeth have been stable ever since. CAH is a serious chronic disorder appearing in children with accelerated dental development and possibly premature loss of primary teeth

    Consequences of Tooth Loss on Oral Function and need for Replacement of Missing Teeth Among Patients Attending Muhimbili Dental Clinic

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    Tanzanian oral health services constitute mainly of tooth extractions. Consequently, individuals susceptible to dental caries and periodontal diseases will have a substantial number of missing teeth, which can affect oral function. The main objective of this study was to determine the consequences of tooth loss on the oral function and need for replacement of lost teeth among patients seeking treatment at the School of Dentistry MUHAS. During a period of three months, patients seeking dental treatment at the School of Dentistry were recruited for the study. Criteria included age of 20 years and above with one or more missing teeth except for third molars. Participants were interviewed for demographic information, chewing ability, symptoms of temporomandibular disorder and perceived need for replacement of missing teeth. Afterwards the subjects were examined to asses: caries status, tooth mobility, occlusal tooth wear, over eruption of unopposed teeth, and signs of temporomandibular disorders. Data was analyzed using Statistical Package for Social Sciences SPSS 16. For comparison of proportions, chi-square analysis and t test were used. A linear regression analysis was performed, with the chewing ability score as the dependent variable and number of POP as the independent variable A total of 361 subjects with mean age of 40.2 years (s.d. = 14.2, range = 20-93 years) were recruited into the study. About half 175 (48.5%) of the subjects reported some difficulty with chewing. Generally the fewer the occluding pairs present the greater the difficulty in chewing observed. Subjects with more than 6 posterior occlusal pairs appeared to have little problem in chewing across the whole range of foods. The frequency of signs and symptoms of TMD and excessive tooth wear increased with decreasing number of posterior occluding pairs, being more evident in subjects with less than 3 posterior occlusal pairs remaining. Over a third of the participants had one or more teeth with severe overeruption but none reported impairment of oral function. More than half of the subjects needed replacement for missing teeth. From this study, it is concluded that tooth loss leading to a dentition of 5 to 6 occlusal pairs impairs chewing of hard foods but not soft foods. Extensive loss of teeth leading to less than 3 POP is associated with increased symptoms of TMD and excessive vii tooth wear of occluding teeth. Need for replacement of missing teeth is high for both anterior and posterior regions with the cost of dentures being the main barrier to replacement of missing teeth. Dental personnel should make an effort to identify individuals with risk of tooth loss in order to retain at least 6 well-distributed posterior occlusal pairs. Dental laboratory services need improvement in order to be able to provide quality replacement of missing teeth at affordable costs. Further long-term multicenter studies to evaluate the consequence of tooth loss and assist in giving a more accurate projection needs for dentures nationwide are required

    Diagnostics Of Supernumerary Teeth In Orthodontic Relapse

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    Aim: increasing the effectiveness of diagnosis and further orthodontic-surgical treatment of various clinical forms of hyperdontia (supernumerary teeth) and preventing recurrence with the use of cone-ray computer tomography data in orthodontic practice.Materials and methods. The clinical case of patient (born in 2004) treatment is presented, with severe hyperdontia and retention of teeth that had little effect on the formation of the general configuration of occlusion. The patient's examination and treatment was carried out with the assistance of clinical, anthropometric and radiological data. The clinical method was to examine the patient and formulate a plan for further orthodontic therapy. The radiological method consisted of data analysis of cefalometry by Bjork, Steiner using a computer program and conducting a survey using a cone-ray computer tomography, followed by the use of these data in diagnosis and orthodontic treatment.Results. Following the clinical and radiological methods of examination and subsequent orthodontic surgery, the corresponding end results were obtained:1. The localization and topography of supernumerary teeth as the causes of relapse of pathology with the help of data obtained with the help of CBCT.2. Radiographic picture reflected on the sagital and axial re-formats of tomograms for the diagnosis of supernumerary teeth, is more informative than diagnostics by standard diagnostic protocols.3. After analysis of the study data, a more meaningful protocol of surgical intervention is prescribed.4. Implementation of the results of modern diagnostics significantly influenced on the final result of orthodontic treatment.Conclusions. Thus, in the process of corresponding work installed:– the availability of computer tomography data is crucial for objective and qualitative diagnosis and treatment of hypertension.– the general level of diagnostics during the intervention is significantly increased
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