891 research outputs found
Microabrasion In Tooth Enamel Discoloration Defects: Three Cases With Long-term Follow-ups
Superficial irregularities and certain intrinsic stains on the dental enamel surfaces can be resolved by enamel microabrasion, however, treatment for such defects need to be confined to the outermost regions of the enamel surface. Dental bleaching and resin-based composite repair are also often useful for certain situations for tooth color corrections. This article presented and discussed the indications and limitations of enamel microabrasion treatment. Three case reports treated by enamel microabrasion were also presented after 11, 20 and 23 years of follow-ups.224347354Akin, M., Basciftci, F.A., Can white spot lesions be treated effectively? (2012) Angle Orthodontist, 82, pp. 770-775Ardu, S., Benbachir, N., Stavridakis, M., Dietschi, D., Krejci, I., Feilzer, A., A combined chemo-mechanical approach for aesthetic management of superficial enamel defects (2009) Br Dent J, 206, pp. 205-208Bailey, R.W., Christen, A.G., Effects of a bleaching technic on the labial enamel of human teeth stained with endemic dental fluorosis (1970) J Dent Res, 49, pp. 168-170Bassir, M.M., Bagheri, G., Comparison between phosphoric acid and hydrochloric acid in microabrasion technique for the treatment of dental fluorosis (2013) J Conserv Dent, 16, pp. 41-44Briso, A., Lima, A., Goncalves, R., Gallinari, M., Santos, P.D., Transenamel and transdentinal penetration of hydrogen peroxide applied to cracked or microabrasioned enamel (2014) Oper Dent, 39, pp. 166-173Castro, K.S., Araújo, F.A.C., Duarte, R.M., Sampaio, F.C., Meireles, S.S., Acceptability, efficacy and safety of two treatment protocols for dental fluorosis: A randomized clinical trial (2014) J Dent, , doi: 10.1016/j.jdent.2014.01.011. Epub ahead of printCelik, E.U., Yildiz, G., Yazkan, B., Clinical evaluation of enamel microabrasion for the aesthetic management of mild-to-severe dental fluorosis (2013) J Esthet Restor Dent, 25, pp. 422-430Celik, E.U., Yildiz, G., Yazkan, B., Comparison of enamel microabrasion with a combined approach to the esthetic management of fluorosed teeth (2013) Oper Dent, 38, pp. 134-143Chhabra, N., Singbal, K.P., Viable approach to manage superficial enamel discoloration (2010) Contemp Clin Dent, 1, pp. 284-287Croll, T.P., Enamel microabrasion for removal of superficial dysmineralization and decalcification defects (1990) J Am Dent Assoc, 120, pp. 411-415Croll, T.P., (1991) Enamel Microabrasion, , Chicago: QuintessenceCroll, T.P., Hastening the enamel microabrasion procedure eliminating defects, cutting treatment time (1993) J Am Dent Assoc, 124, pp. 87-90Croll, T.P., Bullock, G.A., Enamel microabrasion for removal of smooth surface decalcification lesions (1994) J Clin Orthod, 28 (365), p. 70Croll, T.P., Cavanaugh, R.R., Enamel color modification by controlled hydrochloric acid-pumice abrasion. I. technique and examples (1986) Quintessence Int, 17, pp. 81-87Croll, T.P., Segura, A., Donly, K.J., Enamel microabrasion: New considerations in 1993 (1993) Pract Periodontics Aesthet Dent, 5, pp. 19-28. , quiz 29Dixit, U.B., Shetty, R.M., Comparison of soft-tissue, dental, and skeletal characteristics in children with and without tongue thrusting habit (2013) Contemp Clin Dent, 4, pp. 2-6Donly, K.J., O'Neill, M., Croll, T.P., Enamel microabrasion: A microscopic evaluation of the abrosion effect (1992) Quintessence Int, 23, pp. 175-179Fragoso, L.S., Lima, D.A., Alexandre, R.S., Bertoldo, C.E., Aguiar, F.H., Lovadino, J.R., Evaluation of physical properties of enamel after microabrasion, polishing, and storage in artificial saliva (2011) Biomed Mater, 6 (3), p. 035001. , doi: 10.1088/1748-6041/6/3/035001Fujimoto, S., Yamaguchi, K., Gunjigake, K., Clinical estimation of mouth breathing (2009) Am J Orthod Dentofacial Orthop, 136 (630), p. 7Haywood, V.B., Heymann, H.O., Nightguard vital bleaching: How safe is it? (1991) Quintessence Int, 22, pp. 515-523Kendell, R.L., Hydrochloric acid removal of brown fluorosis stains: Clinical and scanning electron micrographic observations (1989) Quintessence Int, 20, pp. 837-839Killian, C.M., Conservative color improvement for teeth with fluorosis-type stain (1993) J Am Dent Assoc, 124, pp. 72-74Killian, C.M., Croll, T.P., Enamel microabrasion to improve enamel surface texture (1990) J Esthet Dent, 2, pp. 125-128Limeback, H., Vieira, A.P., Lawrence, H., Improving esthetically objectionable human enamel fluorosis with a simple microabrasion technique (2006) Eur J Oral Sci, 114, pp. 123-129Machado, L.S., Sundfeld, N.D., Oliveira, G.B., Carvalho, T.C., Oliveira, F.G., Sundfeld, R.H., Combining enamel microabrasion and dental bleaching: Recovering smile aesthetics (2013) Dent Today, 32, pp. 110-111McCloskey, R.J., A technique for removal of fluorosis stains (1984) J Am Dent Assoc, 109, pp. 63-64Murphy, T.C., Willmot, D.R., Rodd, H.D., Management of postorthodontic demineralized white lesions with microabrasion: A quantitative assessment (2007) Am J Orthod Dentofacial Orthop, 131, pp. 27-33Nahsan, F.P., Silva, L.M., Baseggio, W., Franco, E.B., Francisconi, P.A., Mondelli, R.F., Conservative approach for a clinical resolution of enamel white spot lesions (2011) Quintessence Int, 42, pp. 423-426Paula, A., Santos, P.H., Oliveira, F.G., Machado, L.S., Neto, D.S., Sundfeld, R.H., Integrating techniques to restore an adolescent's smile (2012) Dent Today, 31 (88), pp. 90-91Price, R.B., Loney, R.W., Doyle, M.G., Moulding, M.B., An evaluation of a technique to remove stains from teeth using microabrasion (2003) J Am Dent Assoc, 134, pp. 1066-1071Reston, E.G., Corba, D.V., Ruschel, K., Tovo, M.F., Barbosa, A.N., Conservative approach for esthetic treatment of enamel hypoplasia (2011) Oper Dent, 36, pp. 340-343Rodrigues, M.C., Mondelli, R.F., Oliveira, G.U., Franco, E.B., Baseggio, W., Wang, L., Minimal alterations on the enamel surface by micro-abrasion: In vitro roughness and wear assessments (2013) J Appl Oral Sci, 21, pp. 112-117Segura, A., Donly, K.J., Wefel, J.S., Drake, D., Effect of enamel microabrasion on bacterial colonization (1997) Am J Dent, 10 (272), p. 4Sheoran, N., Garg, S., Damle, S.G., Dhindsa, A., Opal, S., Gupta, S., Esthetic management of developmental enamel opacities in young permanent maxillary incisors with two microabrasion techniques a split mouth study (2014) J Esthet Restor Dent, , doi: 10.1111/jerd.12096. Epub ahead of printSundfeld, R.H., Croll, T.P., Briso, A.L., Alexandre, R.S., Sundfeld, N.D., Considerations about enamel microabrasion after 18 years (2007) Am J Dent, 20, pp. 67-72Sundfeld, R.H., Rahal, V., Croll, T.P., de Alexandre, R.S., Briso, A.L., Enamel microabrasion followed by dental bleaching for patients after orthodontic treatment case reports (2007) J Esthet Restor Dent, 19, pp. 71-77Yamaguchi, K., Morimoto, Y., Nanda, R.S., Ghosh, J., Tanne, K., Morphological differences in individuals with lip competence and incompetence based on electromyographic diagnosis (2000) J Oral Rehabil, 27, pp. 893-90
Electron transport in the dye sensitized nanocrystalline cell
Dye sensitised nanocrystalline solar cells (Gr\"{a}tzel cells) have achieved
solar-to-electrical energy conversion efficiencies of 12% in diffuse daylight.
The cell is based on a thin film of dye-sensitised nanocrystalline TiO
interpenetrated by a redox electrolyte. The high surface area of the TiO
and the spectral characteristics of the dye allow the device to harvest 46% of
the solar energy flux. One of the puzzling features of dye-sensitised
nano-crystalline solar cells is the slow electron transport in the titanium
dioxide phase. The available experimental evidence as well as theoretical
considerations suggest that the driving force for electron collection at the
substrate contact arises primarily from the concentration gradient, ie the
contribution of drift is negligible. The transport of electrons has been
characterised by small amplitude pulse or intensity modulated illumination.
Here, we show how the transport of electrons in the Gr\"{a}tzel cell can be
described quantitatively using trap distributions obtained from a novel charge
extraction method with a one-dimensional model based on solving the continuity
equation for the electron density. For the first time in such a model, a back
reaction with the I ions in the electrolyte that is second order in the
electron density has been included.Comment: 6 pages, 5 figures, invited talk at the workshop 'Nanostructures in
Photovoltaics' to appear in Physica
Longitudinal association between preschool fussy eating and body composition at 6 years of age: The Generation R Study
Background: Children's fussy eating behavior has been related to both underweight and overweight in cross-sectional studies, but the direction of these associations and the relation with more detailed measures of body composition remains unclear. We aimed to examine whether fussy eating at age 4 years is longitudinally related to body mass index (BMI), fat mass index (FMI) and fat-free mass index (FFMI) at 6 years of age. Methods: This study was embedded in Generation R, a population-based, prospective cohort. Data were available for 4191 children. The Children's Eating Behaviour Questionnaire (CEBQ), administered at age 4 years, was used to derive a fussy eating profile. This profile is characterized by high scores on food avoidant scales and low scores on food approach scales. At age 6 years, height and weight were measured at our research center. Body fat and fat-free mass were measured using Dual-energy-X-ray absorptiometry. We used age- and sex-specific standard deviation scores (SDS) for all outcomes. Results: After adjustment for confounders, the fussy eating profile was related to lower BMI-SDS (B=-0.37, 95 % CI: -0.47;-0.26), lower FMI-SDS (B=-0.22, 95 % CI: -0.33;-0.12) and lower FFMI-SDS (B=-0.41, 95 % CI: -0.54;-0.29). When adjusting for baseline BMI at 4 years, the fussy eating profile predicted a 0.11 lower BMI-SDS at age 6 (95 % CI: -0.19;-0.04). This change in BMI was mainly due to a decrease in FFMI (B=-0.19, 95 % CI: -0.29;-0.09). Fussy eaters also had a higher risk of becoming underweight than non-fussy eaters (OR=2.28, 95 % CI: 1.34;3.87). Conclusions: Our findings suggest that young fussy eaters are at risk of having a lower fat free mass and of becoming underweight over a 2-year period. This implies that fussy eaters may benefit from careful monitoring to prevent an adverse growth development
Modelling the impact of school reopening and contact tracing strategies on Covid-19 dynamics in different epidemiologic settings in Brazil
This study was funded by the Brazilian National Council for Scientific and Technological Development (CNPq) [grant number 402834/2020-8]. MEB received a technological and industrial scholarship from CNPq [grant number 315854/2020-0]. LSF received a master's scholarship from Coordination for the Improvement of Higher Education Personnel (CAPES) [finance code 001]. SP was supported by São Paulo Research Foundation (FAPESP) [grant number 2018/24037-4]. AMB received a technological and industrial scholarship from CNPq [grant number 402834/2020-8]. CF was supported by FAPESP [grant numbers 2019/26310-2 and 2017/26770-8]. MQMR received a postdoctoral scholarship from CAPES [grant number 305269/2020-8]. LMS received a technological and industrial scholarship from CNPq [grant number 315866/2020-9]. RSK has been supported by CNPq [grant number 312378/2019-0]. PIP has been supported by CNPq [grant number 313055/2020-3]. JAFD-F has been supported by CNPq productivity fellowship and the National Institutes for Science and Technology in Ecology, Evolution and Biodiversity Conservation (INCT-EEC), supported by MCTIC/CNPq [grant number 465610/2014-5] and Goiás Research Foundation (FAPEG) [grant number 201810267000023]. RAK has been supported by CNPq [grant number 311832/2017-2] and FAPESP [grant number 2016/01343-7]. CMT has been supported by CNPq productivity fellowship and the National Institute for Health Technology Assessment (IATS) [grant number 465518/2014-1].Peer reviewedPublisher PD
State transfer in dissipative and dephasing environments
By diagonalization of a generalized superoperator for solving the master
equation, we investigated effects of dissipative and dephasing environments on
quantum state transfer, as well as entanglement distribution and creation in
spin networks. Our results revealed that under the condition of the same
decoherence rate , the detrimental effects of the dissipative
environment are more severe than that of the dephasing environment. Beside
this, the critical time at which the transfer fidelity and the
concurrence attain their maxima arrives at the asymptotic value
quickly as the spin chain length increases. The transfer
fidelity of an excitation at time is independent of when the system
subjects to dissipative environment, while it decreases as increases when
the system subjects to dephasing environment. The average fidelity displays
three different patterns corresponding to , and . For
each pattern, the average fidelity at time is independent of when the
system subjects to dissipative environment, and decreases as increases when
the system subjects to dephasing environment. The maximum concurrence also
decreases as increases, and when , it arrives at an
asymptotic value determined by the decoherence rate and the structure
of the spin network.Comment: 12 pages, 6 figure
Recent glitches detected in the Crab pulsar
From 2000 to 2010, monitoring of radio emission from the Crab pulsar at
Xinjiang Observatory detected a total of nine glitches. The occurrence of
glitches appears to be a random process as described by previous researches. A
persistent change in pulse frequency and pulse frequency derivative after each
glitch was found. There is no obvious correlation between glitch sizes and the
time since last glitch. For these glitches and
span two orders of magnitude. The pulsar suffered the
largest frequency jump ever seen on MJD 53067.1. The size of the glitch is
6.8 Hz, 3.5 times that of the glitch occured in
1989 glitch, with a very large permanent changes in frequency and pulse
frequency derivative and followed by a decay with time constant 21 days.
The braking index presents significant changes. We attribute this variation to
a varying particle wind strength which may be caused by glitch activities. We
discuss the properties of detected glitches in Crab pulsar and compare them
with glitches in the Vela pulsar.Comment: Accepted for publication in Astrophysics & Space Scienc
PDGF-B gene therapy accelerates bone engineering and oral implant osseointegration
Platelet-derived growth factor-BB (PDGF-BB) stimulates repair of healing-impaired chronic wounds such as diabetic ulcers and periodontal lesions. However, limitations in predictability of tissue regeneration occur due, in part, to transient growth factor bioavailability in vivo. Here, we report that gene delivery of PDGF-B stimulates repair of oral implant extraction socket defects. Alveolar ridge defects were created in rats and were treated at the time of titanium implant installation with a collagen matrix containing an adenoviral (Ad) vector encoding PDGF-B (5.5 x 10(8) or 5.5 x 10(9) pfu ml(-1)), Ad encoding luciferase (Ad-Luc; 5.5 x 10(9) pfu ml(-1); control) or recombinant human PDGF-BB protein (rhPDGF-BB, 0.3 mg ml(-1)). Bone repair and osseointegration were measured through backscattered scanning electron microscopy, histomorphometry, micro-computed tomography and biomechanical assessments. Furthermore, a panel of local and systemic safety assessments was performed. Results indicated that bone repair was accelerated by Ad-PDGF-B and rhPDGF-BB delivery compared with Ad-Luc, with the high dose of Ad-PDGF-B more effective than the low dose. No significant dissemination of the vector construct or alteration of systemic parameters was noted. In summary, gene delivery of Ad-PDGF-B shows regenerative and safety capabilities for bone tissue engineering and osseointegration in alveolar bone defects comparable with rhPDGF-BB protein delivery in vivo
Antibody response in patients admitted to the hospital with suspected SARS-CoV-2 infection: results from a multicenter study across Spain
Aim: To evaluate the serological response against SARS-CoV-2 in a multicenter study representative of the Spanish COVID pandemic.
Methods: IgG and IgM + IgA responses were measured on 1466 samples from 1236 Spanish COVID-19 patients admitted to the hospital, two commercial ELISA kits (Vircell SL, Spain) based on the detection of antibodies against the viral spike protein and nucleoprotein, were used.
Results: Approximately half of the patients presented antibodies (56.8% were IgM + IgA positive and 43.0% were IgG positive) as soon as 2 days after the first positive PCR result. Serological test positivity increased with time from the PCR test, and 10 days after the first PCR result, 91.5% and 88.0% of the patients presented IgM + IgA and IgG antibodies, respectively.
Conclusion: The high values of sensitivity attained in the present study from a relatively early period of time after hospitalization support the use of the evaluated serological assays as supplementary diagnostic tests for the clinical management of COVID-19
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