scholarly journals Light intensity of the light-curing units in private clinics in the city of Cuenca, Ecuador

2020 ◽  
Vol 8 (2) ◽  
pp. 124-130
Author(s):  
Fernando Mauricio Villalta Mendoza ◽  
Anabel Priscila Rodas Jaramillo ◽  
Joe Javier Lalangui Matamoros ◽  
Ana Mischell Ajila Bohórquez ◽  
Iván Andrés Palacios Astudillo
Keyword(s):  
Light Intensity ◽  
Dental Treatment ◽  
Fiber Fracture ◽  
Cross Sectional ◽  
Light Intensities ◽  
Light Curing ◽  
Treatment Objective ◽  
Dental Offices ◽  
The City ◽  
Halogen Lamps

Introduction: Light intensity emitted by the curing lamps represents an essential factor in the activation of photosensitive materials. The adequate supply of intensity, as well as the correct functioning of the device, it ensures a correct dental treatment. Objective: To know the light intensity, type, and fiber state of the curing lamps used in private dental offices in the city of Cuenca - Ecuador. Materials and methods: The cross-sectional descriptive study assessed the light intensity of 366 light-curing lamps from private clinics with the use of a Bluephase Meter II radiometer, besides the Likert-scale based evaluation of its type and condition. Data analysis was done with the software R v.3.2 and its interface R-Studio v.1.2. Results: Inadequate light intensities were observed in 18% of the total analyzed units. Inadequate light intensities corresponded at 46% of Halogen lamps, and 12% of LED units. Likewise, 17% of units presented fiber fracture, while 52% showed residues of biomaterials on it. The predominant diameter in the units was 8mm, representing 65% of the total of light-curing lamps analyzed. Conclusions: LED lamps presented adequate light intensities in higher proportion in comparison to halogen lamps. It was shown that the presence of fractures and residues decrease the intensity of the photocuring units. Furthermore, we indicate that a periodic control of the light-curing units is necessary to prevent future problems in oral treatments.

Battery Charge Affects the Stability of Light Intensity from Light-emitting Diode Light-curing Units

2017 ◽  
Vol 42 (5) ◽  
pp. 497-504 ◽  
Author(s):  
A Tongtaksin ◽  
C Leevailoj
Keyword(s):  
Light Intensity ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Bottom Surface ◽  
Light Emitting ◽  
Led Light ◽  
Battery Charge ◽  
Light Intensities ◽  
Light Curing ◽  
The Stability

SUMMARY This study investigated the influence of battery charge levels on the stability of light-emitting diode (LED) curing-light intensity by measuring the intensity from fully charged through fully discharged batteries. The microhardness of resin composites polymerized by the light-curing units at various battery charge levels was measured. The light intensities of seven fully charged battery LED light-curing units—1) LY-A180, 2) Bluephase, 3) Woodpecker, 4) Demi Plus, 5) Saab II, 6) Elipar S10, and 7) MiniLED—were measured with a radiometer (Kerr) after every 10 uses (20 seconds per use) until the battery was discharged. Ten 2-mm-thick cylindrical specimens of A3 shade nanofilled resin composite (PREMISE, Kerr) were prepared per LED light-curing unit group. Each specimen was irradiated by the fully charged light-curing unit for 20 seconds. The LED light-curing units were then used until the battery charge fell to 50%. Specimens were prepared again as described above. This was repeated again when the light-curing units' battery charge fell to 25% and when the light intensity had decreased to 400 mW/cm2. The top/bottom surface Knoop hardness ratios of the specimens were determined. The microhardness data were analyzed by one-way analysis of variance with Tukey test at a significance level of 0.05. The Pearson correlation coefficient was used to determine significant correlations between surface hardness and light intensity. We found that the light intensities of the Bluephase, Demi Plus, and Elipar S10 units were stable. The intensity of the MiniLED unit decreased slightly; however, it remained above 400 mW/cm2. In contrast, the intensities of the LY-A180, Woodpecker, and Saab II units decreased below 400 mW/cm2. There was also a significant decrease in the surface microhardnesses of the resin composite specimens treated with MiniLED, LY-A180, Woodpecker, and Saab II. In conclusion, the light intensity of several LED light-curing units decreased as the battery was discharged, with a coincident reduction in the units' ability to polymerize resin composite. Therefore, the intensity of an LED light-curing unit should be evaluated during the life of its battery charge to ensure that sufficient light intensity is being generated.

scholarly journals Optimization of Photopolymerization Process of Dental Composites

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 779
Author(s):  
Tsanka Dikova ◽  
Jordan Maximov ◽  
Vladimir Todorov ◽  
Georgi Georgiev ◽  
Vladimir Panov
Keyword(s):  
Light Intensity ◽  
Regression Models ◽  
Irradiation Time ◽  
Composite Layer ◽  
High Hardness ◽  
Dental Composites ◽  
Light Curing ◽  
Dental Offices ◽  
Curing Regimes ◽  
Composite Restoration

The aim of this paper is to perform optimization of photopolymerization process of dental composites in order to obtain maximum hardness. Samples (5 mm diameter; 2, 3 and 4 mm thickness) were made of Universal Composite (UC), Bulk fill Composite (BC) and Flowable Composite (FC). Light curing of specimens was performed with 600, 1000 and 1500 mW/cm2 light intensity and an irradiation time of 20, 40 and 60 s. Vickers microhardness on the top and bottom surfaces of samples was measured. Optimization was carried out via regression analysis using QStatLab software. Photopolymerization process parameters were calculated using a specially designed MatLab software-based algorithm. For all composites, regression models for hardness on top and bottom surfaces of composite layer were established. Layer thickness as well as hardness on top and bottom surfaces of each composite was calculated for 21 curing modes varying with light intensity and irradiation time. It was established that photopolymerization guidelines only of FC manufacturer guarantee the required hardness, while recommended regimes for UC and BC did not satisfy this requirement. Tables, containing recommended light curing regimes, were developed for three composite types, guaranteeing high hardness of composite restoration. They were designed to facilitate work of dentists in dental offices.

scholarly journals To Determine The Functional Efficacy of Led Units in Various Clinical Offices

2015 ◽  
Vol 03 (01) ◽  
pp. 034-038
Author(s):  
Kamal Nabhi ◽  
Ajay Chhabra ◽  
Varun Jindal ◽  
Keyword(s):  
Standard Deviation ◽  
Light Intensity ◽  
Linear Relationship ◽  
Selection Criteria ◽  
Resin Composites ◽  
Positive Linear Relationship ◽  
Light Intensities ◽  
Composites Materials ◽  
Dental Offices ◽  
The Individual

Abstract Aim: Light units used for polymerization of resin composites are subject to deterioration with age, and frequent maintenance is required to maintain optimal efficacy. The aim of this study was to examine the efficacy of LED units in private dental offices in Baddi (H.P) for polymerization of resin composites. Materials and Methods: Twenty dental offices met all selection criteria and agreedto participate in the study. To measure light intensity, an analogue radiometer was used. The probe of each LED unit was placed and then measurements of light intensities were recorded for each light unit and the data was statistically analysed. Results: The light intensity of the individual units varied widely. The results revealed that there was error of 35% and a standard deviation of 155.76 among the intensities of various LED Units checked in the study. Conclusions: Light polymerization units in private dental offices displayed a wide rangein light intensity, and many had below-recommended levels. A positive linear relationship was found between light intensity and photoactivation effectiveness. Dentists should regularly monitor the condition of light units and replace deteriorating parts.

Iranians' Attitudes About Possible Human Immunodeficiency Virus Transmission in Dental Settings

2007 ◽  
Vol 28 (2) ◽  
pp. 234-237 ◽  
Author(s):  
Mehrdad Askarian ◽  
Kamran Mirzaei ◽  
Ojan Assadian
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dental Treatment ◽  
Virus Transmission ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Immunodeficiency Virus ◽  
Dental Offices ◽  
Immunodeficiency Syndrome ◽  
Dental Assistants ◽  
Hiv Aids

We conducted a cross-sectional survey from October through December 2004 of 8,312 residents of Shiraz, Iran, to investigate Iranians' perceptions about undergoing dental treatment in dental offices where other patients or the dentist and/or dental assistants are infected with human immunodeficiency virus (HIV). Most survey respondents (83%) had acceptable general knowledge about the mode of transmission of HIV and about acquired immunodeficiency syndrome (AIDS); however, many misconceptions were observed. A negative association was detected between the level of concern about contracting HIV/AIDS and the intention to continue treatment in services where patients with HIV/AIDS were also treated or where the dentist and/or dental assistants had HIV/AIDS.

scholarly journals Residual monomer in a composite resin after light-curing with different sources, light intensities and spectra of radiation

2006 ◽  
Vol 17 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Ivan A. Filipov ◽  
Stoyan B. Vladimirov
Keyword(s):  
Light Intensity ◽  
Composite Resin ◽  
Halogen Lamp ◽  
Light Spectrum ◽  
Residual Monomer ◽  
Spectral Radiation ◽  
Significance Level ◽  
Light Intensities ◽  
Light Curing ◽  
Different Sources

The purpose of this study was to investigate the amount of residual monomer in a composite resin after light-curing with different sources, light intensities and spectra of radiation. The resin specimens (4 mm in diameter; 2 mm thick) (n=5) were inserted in Plexglass matrixes and light-cured with a halogen lamp, LED and PAC units for 40, 40 and 5 s, respectively. The polymerized specimens were ground and 25 mg of each specimen were immersed in 8 mL 96% ethanol for 24 h to extract the residual monomer. The amount of residual monomer was determined by the standard straight line method. The light spectrum of the different LCUs was shot and processed through researches of the absorbation of the standard solutions at a level of lambda= 275 nm and their extracts. Data were analyzed statistically by variational dispersion analysis and Tukey-Kramer test at 5% significance level. It was observed that, the halogen lamp produced the smallest amount of monomer under sufficient light intensity. The spectrum of light radiation of PAC was within the limits of 450- 490 nm and was of extremely high intensity. This imposes the use of short-limited light impulses, but also might lead to deterioration quality of polymerization. The LED unit had the best spectral radiation. An increase of light intensity was proved necessary.

Perfil da Linguagem em Pacientes com Acidente Vascular Encefálico Atendidos pelo Serviço Assistencial Domiciliar Multidisciplinar em Porto Velho – Rondônia

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (1) ◽  
pp. 34-42
Author(s):  
Amanda Leite Silva Cabral ◽  
Flávia Peres Lima ◽  
Jéssica Iara Costa Bessa Paraguassú
Keyword(s):  
Communication Skills ◽  
Oral Language ◽  
Care Service ◽  
Oral Communication ◽  
Etiologic Factor ◽  
Test Protocol ◽  
Cross Sectional ◽  
One Year ◽  
The City ◽  
Porto Velho

Introdução: A afasia é uma das sequelas mais importantes que ocorrem após lesão cerebral de acidente vascular encefálico (AVE). Objetivos: Identificar o perfil da linguagem oral de pacientes com AVE, atendidos pelo Serviço Assistencial Multidisciplinar Domiciliar (SAMD) na cidade de Porto Velho – RO. Materiais e Métodos: Trata-se de um estudo transversal e quantitativo, realizado na residência dos pacientes que estavam sendo atendidos pelo SAMD. Onde foi utilizado o protocolo de Teste de Reabilitação das Afasias composto inicialmente de um questionário que foi aplicados com os familiares dos pacientes para coletar dados quanto ao AVE e os Testes de Comunicação Oral para avaliar dos pacientes. Resultados: Foram avaliados 11 sujeitos com AVE e oito sujeitos apresentaram afasia emissiva do tipo Broca (100%) com presença de agramatismo e anomia (87,5%), e déficit na organização da comunicação e na memória (100%). Referente à etiologia do AVE, verificou-se que 62,5% dos sujeitos apresentaram etiologia decorrente de hipertensão, com tempo de sequelas com tempo entre um ano menos e a três anos (37,5%). Todos os sujeitos (100%) eram muito falantes antes do AVE, porem 50% continuaram muito falantes após o AVE e os outros 50% se tornaram pouco falantes. Conclusão: Os resultados evidenciam que a maioria dos sujeitos apresentaram afasia emissiva do tipo Broca, em decorrência de Acidente Vascular Encefálico Isquêmico tendo como fator etiológico a hipertensão. Desencadeando alterações de linguagem como anomia e agramatismo, afetando ainda suas habilidades de comunicação como a memória e a organização da linguagem. Introduction: Aphasia is one of the most important sequels that occur after brain injury from stroke. Objectives: To identify the oral language profile of patients with stroke, assisted by the Multidisciplinary Home Care Service (SAMD) in the city of Porto Velho - RO. Materials and Methods: This was a cross-sectional and quantitative study carried out at the residence of the patients who were being treated by the SAMD. Where the Aphasia Rehabilitation Test protocol was used, composed initially of a questionnaire that was applied with the relatives of the patients to collect data regarding the AVE and the Oral Communication Tests to evaluate the patients. Results: Eleven subjects with EVA were evaluated, and eight subjects presented Embryonic Emphasis of Broca type (100%) with presence of agramatism and anomia (87.5%), and deficits in the organization of communication and memory (100%). Regarding the etiology of the AVE, 62.5% of the subjects presented etiology due to hypertension, with sequelae time between one year less and three years (37.5%). All subjects (100%) were very talented before the AVE, but 50% remained very talented after the AVE and the other 50% became less talkative. Conclusion: The results show that most of the subjects presented Embryonic Emphasis of the Broca type, due to Ischemic Stroke, having as etiologic factor hypertension. Unleashing language changes such as anomie and agramatism, still affecting his communication skills as memory and the organization of language.

Skull and Face Injuries and Associated Factors in Pedestrian Victims of Traffic Accidents: A Single Trauma Center Analysis

2020 ◽  
Vol 2 (1) ◽  
pp. 53-59
Author(s):  
Josimara A. de Araújo Varela ◽  
Tatiana F.T. Palitot ◽  
Smyrna L.X. de Souza ◽  
Alidianne F.C. Cavalcanti ◽  
Alessandro L. Cavalcanti
Keyword(s):  
Medical Records ◽  
Associated Factors ◽  
Traffic Accidents ◽  
Age Group ◽  
Chi Square ◽  
Cross Sectional ◽  
Significance Level ◽  
The Face ◽  
Chi Square Test ◽  
The City

Objective: This study aimed to analyze the presence of lesions in the skull and face and the associated factors in pedestrian victims of traffic accidents. Methods: A cross-sectional, descriptive-analytical study carried out through the analysis of medical records of pedestrian victims of traffic accidents in an emergency service in the city of Campina Grande, Brazil, during the year of 2016. Information was collected regarding gender, age group, day of the week, time of the accident, type of vehicle involved, presence of trauma to the skull and face, and outcomes. The Chi-square and Fisher's Exact tests were used, with a significance level of 5%. Results: A total of 1,884 medical records were evaluated, out of which 7.1% (n = 133) involved pedestrians. Men were the most frequent victims (68.4%), and victims of age 60 years old or over (30.5%) predominated. Almost one-third of the cases were recorded during the weekends (30.5%), and the most prevalent time was at night (52.7%). Regarding the type of vehicle involved, motorcycles predominated (47.4%). Head trauma was present in 37.6% of victims, while facial injuries corresponded to 8.2%. In 12% of cases, the victims died. The variables of gender, age group, occurrence on weekends, and trauma to the face showed a statistically significant association with the occurrence of traffic accidents (Chi-square test; p<0.05). Conclusion: Among pedestrian victims of traffic accidents, there is a predominance of men aged 65 years or over. Accidents are frequent at night, and motorcycles are the main vehicles involved. The presence of trauma to the skull and face regions is high.

scholarly journals Effect of chlorophyll biosynthesis-related genes on the leaf color in Hosta (Hosta plantaginea Aschers) and tobacco (Nicotiana tabacum L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingying Zhang ◽  
Changhai Sui ◽  
Huimin Liu ◽  
Jinjiao Chen ◽  
Zhilin Han ◽  
...  
Keyword(s):  
Light Intensity ◽  
Antioxidant Capacity ◽  
Aminolevulinic Acid ◽  
Chlorophyll Biosynthesis ◽  
Expression Level ◽  
Virus Induced Gene Silencing ◽  
Leaf Color ◽  
Color Changes ◽  
Light Intensities ◽  
Structure Changes

Abstract Background ‘Regal Splendour’ (Hosta variety) is famous for its multi-color leaves, which are useful resources for exploring chloroplast development and color changes. The expressions of chlorophyll biosynthesis-related genes (HrHEMA, HrPOR and HrCAO) in Hosta have been demonstrated to be associated with leaf color. Herein, we isolated, sequenced, and analyzed HrHEMA, HrPOR and HrCAO genes. Subcellular localization was also performed to determine the location of the corresponding enzymes. After plasmid construction, virus-induced gene silencing (VIGS) was carried out to reduce the expressions of those genes. In addition, HrHEMA-, HrPOR- and HrCAO-overexpressing tobacco plants were made to verify the genes function. Changes of transgenic tobacco were recorded under 2000 lx, 6000 lx and 10,000 lx light intensity. Additionally, the contents of enzyme 5-aminolevulinic acid (5-ALA), porphobilinogen (PBG), chlorophyll a and b (Chla and Chlb), carotenoid (Cxc), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and catalase (CAT) under different light intensities were evaluated. Results The silencing of HrHEMA, HrPOR and HrCAO genes can induce leaf yellowing and chloroplast structure changes in Hosta. Specifically, leaves of Hosta with HrCAO silencing were the most affected, while those with HrPOR silencing were the least affected. Moreover, all three genes in tobacco were highly expressed, whereas no expression was detected in wild-type (WT). However, the sensitivities of the three genes to different light intensities were different. The highest expression level of HrHEMA and HrPOR was detected under 10,000 lx of illumination, while HrCAO showed the highest expression level under 6000 lx. Lastly, the 5-ALA, Chla, Cxc, SOD, POD, MDA, Pro and CAT contents in different transgenic tobaccos changed significantly under different light intensities. Conclusion The overexpression of these three genes in tobacco enhanced photosynthesis by accumulating chlorophyll content, but the influential level varied under different light intensities. Furthermore, HrHEMA-, HrPOR- and HrCAO- overexpressing in tobacco can enhance the antioxidant capacity of plants to cope with stress under higher light intensity. However, under lower light intensity, the antioxidant capacity was declined in HrHEMA-, HrPOR- and HrCAO- overexpressing tobaccos.

scholarly journals A cross-sectional study to assess knowledge of women about cervical cancer: an urban and rural comparison

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Małgorzata Lesińska-Sawicka
Keyword(s):  
Cervical Cancer ◽  
Life Expectancy ◽  
Correct Answer ◽  
Rural Areas ◽  
Urban Areas ◽  
Statistical Significance ◽  
Average Life Expectancy ◽  
Cross Sectional ◽  
Awareness Campaigns ◽  
The City

Abstract Introduction Cervical cancer and its etiopathogenesis, the age of women in whom it is diagnosed, average life expectancy, and prognosis are information widely covered in scientific reports. However, there is no coherent information regarding which regions—urban or rural—it may occur more often. This is important because the literature on the subject reports that people living in rural areas have a worse prognosis when it comes to detection, treatment, and life expectancy than city dwellers. Material and methods The subjects of the study were women and their knowledge about cervical cancer. The research was carried out using a survey directly distributed among respondents and via the Internet, portals, and discussion groups for women from Poland. Three hundred twenty-nine women took part in the study, including 164 from rural and 165 from urban areas. The collected data enabled the following: (1) an analysis of the studied groups, (2) assessment of the respondents’ knowledge about cervical cancer, and (3) comparison of women’s knowledge depending on where they live. Results The average assessment of all respondents’ knowledge was 3.59, with women living in rural areas scoring 3.18 and respondents from the city—4.01. Statistical significance (p < 0.001) between the level of knowledge and place of residence was determined. The results indicate that an increase in the level of education in the subjects significantly increases the chance of getting the correct answer. In the case of age analysis, the coefficients indicate a decrease in the chance of obtaining the correct answer in older subjects despite the fact that a statistically significant level was reached in individual questions. Conclusions Women living in rural areas have less knowledge of cervical cancer than female respondents from the city. There is a need for more awareness campaigns to provide comprehensive information about cervical cancer to women in rural areas. A holistic approach to the presented issue can solve existing difficulties and barriers to maintaining health regardless of the place of life and residence. Implication for cancer survivors They need intensive care for women’s groups most burdened with risk factors.

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