288 research outputs found

    Multifaceted Access Scheme Using I-Button

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    In Present Scenario the advancement in technology is enormous and therefore the Human working efficiency is increasing day by day. But as there are advantages, there are some disadvantages also like misuse of these technologies. For example if some unauthorized person can get access to the system then we have to suffer a lot. Therefore to overcome this above mentioned problem of security, a Control system can be built to prevent unauthorized access. It is called Access control, which is a system which enables an authority to control access to areas and resources in a given physical facility or computer-based information system. An access control system, within the field of physical security, is generally seen as the second layer in the security of physical structure of such systems. And the advantage of it is that this system contains very high end verification technology which is difficult to be intruded by such unauthorized element. One of the latest, next generation and very advanced technologies which is “I-Button” has all the above mentioned features. In this work a multi-access system has been designed using “i-button” for payment of toll tax, petrol filling and recharge. This system will save time of consumers as well as it will provide secure transaction

    Revitalisation endodontic treatment of traumatised immature teeth: a prospective long-term clinical study

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    Purpose Continuation of root development following revitalisation endodontics (RET) has been shown to be unpredictable with lower success rates in traumatised teeth. This study reports the outcomes for RET in traumatised teeth over a review period of 4 years. Methods A prospective uncontrolled study, where RET was performed on traumatised upper immature anterior teeth with necrotic pulps in 15 children (mean age = 8.3 years), was conducted. Patients were reviewed at 3, 9, 12, 24, and 48 months, where clinical and radiographic assessments were performed. At the last review appointment, patients and parents answered questions assessing their perception and acceptance of tooth colour change over time. McNemar’s Exact test and linear mixed model assessment were used to assess changes in pulpal electrical response and radiographic evidence of continuation of root development over time, respectively. Results There was 83.3% healing with no significant changes in EPT responses, and no significant changes in root lengths, while significant changes in root widths (p < 0.05) and root apex widths (p < 0.001) were found over time. Twenty-five percent of patients and 33% of parents felt that there were changes in tooth colour following RET over time. Conclusion Within the limitations of this study, traumatised teeth treated using RET showed no significant root lengthening, however, acceptable periapical healing, slow thickening of root dentinal walls, and rapid development of apical closure were evident over a period of 43 months. Using Portland cement and omitting minocycline, did not eliminate crown colour change following RET

    Regenerative endodontic therapy (RET) for managing immature non-vital teeth: a national survey of UK paediatric dental specialists and trainees

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    Background: Several guidelines have been published advocating the use of regenerative endodontic therapy (RET) in managing non-vital immature permanent teeth. It is unclear, however, how many UK paediatric dental specialists routinely use this technique and their opinion of its outcomes, and barriers to its use. Aim: To assess the knowledge, experience and the opinion of UK based paediatric dental specialists/trainees (UKPDS/T) and practitioners working in the capacity of paediatric dental specialists on the use of RET. Design: A cross-sectional study using a 22-item questionnaire was developed using the Bristol Online Survey tool and circulated electronically to members of the British Society of Paediatric Dentistry between August and November 2016. Results: Ninety-eight UKPDS/T completed the survey. A quarter of respondents (N = 24, 24.5%) reported using RET. Reasons cited for not using RET included lack of: training (N = 48, 45%), materials (N = 28, 26%), evidence (N = 17, 16%) and suitable cases (N = 6, 6%). Different protocols in terms of disinfection, medicaments, scaffolds, and obturation material were identified. Conclusions: This survey highlights a low uptake of RET by current UKPDS and trainees with several barriers identified. Deviations from the current RET guidelines were identified. Recommendations addressing the use of RET in light of the findings of this survey were made

    Microstructural characterization of laser sintered synthetic calcium phosphate-natural dentine interface for the restoration of enamel surface

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    Tooth sensitivity is a common occurrence and it is caused by acid induced erosion of enamel surface. In this investigation we report the results of calcium phosphate based minerals which are irradiated with lasers ex vivo for the analysis of photo activated densification of minerals. The photo-activation in these minerals may primarily arise from the absorption centres, namely OH- and rare-earth (RE)3+ ion dopants (e.g. Er3 ions) incorporated during synthesis. The loss of hydroxyl group from mineral is characterized using the thermogravimetric technique. The microstructural changes under the conditions of continuous wave (CW) and pulsed laser irradiation are reported together with the measured temperature rise. The preliminary data on surface hardness of occluded dentine with photo-activated calcium phosphate minerals are also reported, for aiming an eventual hardness value of 3300 MPa which is known for natural enamels

    The effect of premature extraction of primary teeth on the subsequent need for orthodontic treatment.

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    Aim: This was primarily to examine the effect of premature extraction of primary teeth (PEPT) on subsequent malocclusion and need for orthodontic treatment in the permanent dentition. The secondary aim was to correlate the effect of PEPT with loss of space in the primary and mixed dentitions. Methods: A predefined protocol was developed and registered prospectively with PROSPERO database. The electronic databases, searched, were MEDLINE, EMBASE, PubMed, and Cochrane Central Register of Controlled Trials. The study designs considered for inclusion were controlled trials, cohort, and case-control studies. Risk of bias was assessed using a validated quality assessment tool. Results: 513 studies were identified. Sixteen studies were included in the systematic review, one study reported on malocclusion, and 15 studies reported on space changes. Narrative synthesis was undertaken owing to the heterogeneity of the included studies. No study examined the effect of PEPT on orthodontic need. Most studies reported on space dimensions used a split-mouth design and were at a high risk of bias. Conclusions: The included literature identified that PEPT led to various features of malocclusion and space loss in the mixed and permanent dentitions. No studies, that met the inclusion criteria, described the effect of PEPT on the subsequent need for orthodontic treatment

    Regenerative Endodontic Technique using a combination of Amoxicillin and Metronidazole. A review and report of two cases

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    The management of non vital anterior permanent teeth in children is a challenge for the clinicians. Once the tooth becomes non vital, the root development ceases, which renders the tooth weak and unable to withstand the physiological forces of mastication. This results in a high fracture rate, and therefore a poor prognosis in the medium to long term. Recently there has been a paradigm shift in the approach to this clinical problem through the use of regenerative endodontics. Despite many case reports, and a few case series that have been reported, the procedure is still shrouded in uncertainty as differing interventions have been used, though broadly based on similar principles. In the Department of Paediatric Dentistry at the Leeds Dental Institute we have used a particular regenerative endodontic technique (RET), using a mixture of two antibiotics (Amoxicillin and Metronidazole). In this paper, we aim to present the rationale for this technique and present two cases successfully treated and followed for up to two years

    A prospective clinical study of regenerative endodontic treatment of traumatized immature teeth with necrotic pulps using bi-antibiotic paste

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    Aim: To evaluate the treatment outcomes of a revitalization endodontic technique (RET) for the management of traumatized immature teeth with necrotic pulps in children. Methodology: Fifteen healthy children (age range = 7–10 years) with traumatized immature maxillary incisors with necrotic pulps treated with bi-antibiotic revitalization endodontic technique were prospectively assessed over approximately two years (mean = 22 months). One operator undertook all treatments, clinical reviews and standardized radiographic exposures with radiographic analysis being carried out by two calibrated experienced clinicians. Crown colour change was assessed using an objective published methodology. Wilcoxon signed-rank test was used to compare root lengths, root dentinal widths and apical foramen widths over time. Results: Interoperator measurement reliability was consistently strong for all measurements. There was no significant difference in root lengths or root dentinal wall widths following RET. A significant difference in apical foramen widths was observed after 2 years (P = 0.013) with resolution of clinical signs of infection in all cases. Despite omitting minocycline and using Portland cement (nonbismuth containing cement), a noticeable crown colour change (yellower, redder and lighter), as measured by an objective colour measurement system with ΔE = 7.39, was recorded. Most patients, however, were satisfied with the aesthetic outcome. Conclusion: Traumatized immature teeth with necrotic pulps treated with revitalization endodontic technique did not demonstrate continuation of root development or dentine formation when assessed by periapical radiographs. However, apical closure and periodontal healing were observed. A measurable change in crown colour (yellower, redder and lighter), with mostly no aesthetic concern to the patients/parents, was also observed

    Antibacterial properties and regenerative potential of Sr²+ and Ce³+ doped fluorapatites; a potential solution for peri-implantitis

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    Scaffolds and implants in orthopaedics and regenerative dentistry usually fail because of bacterial infections. A promising solution would be the development of biomaterials with both significant regenerative potential and enhanced antibacterial activity. Working towards this direction, fluorapatite was synthesised and doped with Sr²+ and Ce³+ ions in order to tailor its properties. After experiments with four common bacteria (i.e. E. Coli, S. Aureus, B. Subtilis, B. Cereus), it was found that the undoped and the Ce³+ doped fluorapatites present better antibacterial response than the Sr²+ doped material. The synthesised minerals were incorporated into chitosan scaffolds and tested with Dental Pulp Stem Cells (DPSCs) to check their regenerative potential. As was expected, the scaffolds containing Sr²+-doped fluorapatite, presented high osteoconductivity leading to the differentiation of the DPSCs into osteoblasts. Similar results were obtained for the Ce³+-doped material, since both the concentration of osteocalcin and the RUNX2 gene expression were considerably higher than that for the un-doped mineral. Overall, it was shown that doping with Ce³+ retains the good antibacterial profile of fluorapatite and enhances its regenerative potential, which makes it a promising option for dealing with conditions where healing of hard tissues is compromised by bacterial contamination

    β-pyrophosphate: A potential biomaterial for dental applications

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    Tooth hypersensitivity is a growing problem affecting both the young and ageing population worldwide. Since an effective and permanent solution is not yet available, we propose a new methodology for the restoration of dental enamel using femtosecond lasers and novel calcium phosphate biomaterials. During this procedure the irradiated mineral transforms into a densified layer of acid resistant iron doped β-pyrophosphate, bonded with the surface of eroded enamel. Our aim therefore is to evaluate this densified mineral as a potential replacement material for dental hard tissue. To this end, we have tested the hardness of β-pyrophosphate pellets (sintered at 1000 °C) and its mineral precursor (brushite), the wear rate during simulated tooth-brushing trials and the cytocompatibility of these minerals in powder form. It was found that the hardness of the β-pyrophosphate pellets is comparable with that of dental enamel and significantly higher than dentine while, the brushing trials prove that the wear rate of β-pyrophosphate is much slower than that of natural enamel. Finally, cytotoxicity and genotoxicity tests suggest that iron doped β-pyrophosphate is cytocompatible and therefore could be used in dental applications. Taken together and with the previously reported results on laser irradiation of these materials we conclude that iron doped β-pyrophosphate may be a promising material for restoring acid eroded and worn enamel

    2-D Electronic Spectroscopy on the light-dependent enzyme protochlorophyllide oxidoreductase

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    In photosynthesis, quantum coherence in light harvesting complexes could form the basis for the highly efficient propagation of excited states within the photosynthetic membranes of bacteria and plants. Recent studies on Photosystem II reaction centres extends the possible relevance of electronic coherence to the photochemical steps of photosynthesis; it was shown that coherent states are sufficiently long-lived, at room temperature, to persist during the initial steps of electron transfer. This extension of quantum coherence, from the energy transfer to the energy trapping steps of photosynthesis, made it timely to investigate if quantum coherence also plays a role in the formation of product states in enzyme catalysis. Given the short timescales involved it was necessary to study an enzyme where the catalytic cycle can be triggered by femtosecond light pulses, so protochlorophyllide oxidoreductase (POR) was selected as an ideal model system. 2-dimensional electronic spectroscopy (2DES) was used to investigate the presence of quantum coherence in the intermediates of the light-dependent reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide) catalysed by POR
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