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1.
Dent Mater ; 36(9): 1201-1213, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32576408

RESUMO

OBJECTIVE: To evaluate the influence of light emitted from two Polywave®, LED light-curing units (LCU) on in vivo pulp temperature (PT) rise and signs of acute inflammatory response in pulps of human premolar having deep Class V preparations. METHODS: Sixty intact, first premolars from 15 volunteers requiring extraction received infiltrative anesthesia. A sterile thermocouple probe was inserted within the pulp tissue through a minute occlusal pulp exposure in only 45 teeth (n = 9) to continuously monitor PT (°C). A deep buccal Class V preparation was created, and the surface was exposed to light from a commercial Polywave LCU (Bluephase 20i (20i), Ivoclar Vivadent) or from an experimental LCU (Exp) using the exposure modes (EM): 1s/Exp and 2s/Exp, 10s/20i, 20s/20i, and 60s/20i. Peak PT and PT rise values above baseline (ΔT) data were evaluated using a one-way ANOVA followed by Tukey's post-hoc test (α = 5%). Teeth used for histological and immunohistochemical analyses (n = 3) were extracted approximately 2 h after exposure to the LCU. RESULTS: No significant difference in peak PT and ΔT values was noted between 2s/Exp and 20s/20i groups, which both exhibited higher values than 1s/Exp and 10s/20i groups (p < 0.001). Dilated and congested blood vessels were seen after exposure to 1s/Exp, 2s/Exp, or 60s/20i EMs. The expression of IL-1ß and TNF-α tended to be more intense when higher irradiance was delivered. SIGNIFICANCE: Although higher irradiance delivered over a short exposure caused lower PT rise than 5.5 °C, such EMs should be used with caution, as they have more potential to harm the pulp tissue.


Assuntos
Luzes de Cura Dentária , Cura Luminosa de Adesivos Dentários , Dente Pré-Molar , Resinas Compostas , Polpa Dentária , Humanos , Temperatura
2.
Dent Mater ; 34(6): 901-909, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29606368

RESUMO

OBJECTIVE: This in vivo study evaluated pulp temperature (PT) rise in human premolars having deep Class V preparations during exposure to a light curing unit (LCU) using selected exposure modes (EMs). METHODS: After local Ethics Committee approval, intact first premolars (n=8) requiring extraction for orthodontic reasons, from 8 volunteers, received infiltrative and intraligamental anesthesia and were isolated using rubber dam. A minute pulp exposure was attained and sterile probe from a wireless, NIST-traceable, temperature acquisition system was inserted into the coronal pulp chamber to continuously monitor PT (°C). A deep buccal Class V preparation was prepared using a high speed diamond bur under air-water spray cooling. The surface was exposed to a Polywave® LED LCU (Bluephase 20i, Ivoclar Vivadent) using selected EMs, allowing 7-min span between each exposure: 10-s in low (10-s/L), 10-s (10-s/H), 30-s (30-s/H), or 60-s (60-s/H) in high mode; and 5-s-Turbo (5-s/T). Peak PT values and PT increases over physiologic baseline levels (ΔT) were subjected to 1-way, repeated measures ANOVAs, and Bonferroni's post-hoc tests (α=0.05). Linear regression analysis was performed to establish the relationship between applied radiant exposure and ΔT. RESULTS: All EMs produced higher peak PT than the baseline temperature (p<0.001). Only 60-s/H mode generated an average ΔT of 5.5°C (p<0.001). A significant, positive relationship was noted between applied radiant exposure and ΔT (r2=0.8962; p<0.001). SIGNIFICANCE: In vivo exposure of deep Class V preparation to Polywave® LED LCU increases PT to values considered safe for the pulp, for most EMs. Only the longest evaluated EM caused higher PT increase than the critical ΔT, thought to be associated with pulpal necrosis.


Assuntos
Luzes de Cura Dentária , Preparo da Cavidade Dentária/métodos , Polpa Dentária/efeitos da radiação , Dente Pré-Molar , Temperatura Alta , Humanos , Extração Dentária
3.
Dent Mater ; 33(11): 1266-1273, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28826611

RESUMO

OBJECTIVE: This study evaluated the temperature increase in swine gingival temperature after exposure to light emitted by a Polywave® LED light curing unit (LCU, Bluephase 20i, Ivoclar Vivadent). METHODS: After local Ethics Committee approval (protocol 711/2015), 40 pigs were subjected to general anesthesia and the LCU tip was placed 5mm from the buccal gingival tissue (GT) close to lower lateral incisors. A thermocouple probe (Thermes WFI, Physitemp) was inserted into the gingival sulcus before and immediately after exposure to light. Real-time temperature (°C) was measured after the following exposure modes were applied: High Power (20s-H, 40s-H, and 60s-H) or Turbo mode (5s-T), either with or without the presence of rubber dam (RD) interposed between the LCU tip and GT (n=10). The presence of gingival lesions after the exposures was also evaluated. Peak temperature (°C) and the temperature increase during exposure over that of the pre-exposure baseline value (ΔT) data were analyzed using 2-way ANOVA followed by Bonferroni's post-hoc test (α=5%). A binary logistic regression analysis determined the risk of gingival lesion development. RESULTS: Without RD, no significant difference in ΔT was observed among 20s-H, 40s-H, and 60s-H groups, which showed the highest temperature values, while the 5s-T exposure showed the lowest ΔT, regardless of RD. RD reduced ΔT only for the 20s-H group (p=0.004). Gingival lesions were predominantly observed using 40s-H, with RD, and 60s-H, with and without RD. SIGNIFICANCE: Exposure to a LCU light might be harmful to swine gingiva only when high radiant exposure values are delivered, regardless of the use of RD.


Assuntos
Luzes de Cura Dentária , Gengiva/efeitos da radiação , Temperatura , Animais , Lesões por Radiação/prevenção & controle , Suínos
4.
J Appl Oral Sci ; 25(2): 140-146, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28403354

RESUMO

Objective: Using Fourier transform infrared analysis (FTIR) in vitro, the effects of varying radiant exposure (RE) values generated by second and third generation LED LCUs on the degree of conversion (DC) and maximum rate of polymerization (Rpmax) of an experimental Lucirin TPO-based RC were evaluated. Material and Methods: 1 mm or 2 mm thick silicon molds were positioned on a horizontal attenuated total reflectance (ATR) unit attached to an infrared spectroscope. The RC was inserted into the molds and exposed to varying REs (18, 36 and 56 J/cm2) using second (Radii Plus, SDI) and third generation LED LCUs (Bluephase G2/Ivoclar Vivadent) or a quartz tungsten based LCU (Optilux 501/SDS Kerr). FTIR spectra (n=7) were recorded for 10 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm-1) immediately after their application to the ATR. The DC was calculated using standard techniques for observing changes in aliphatic to aromatic peak ratios both prior to, and 10 min after curing, as well as during each 1 second interval. DC and Rpmax data were analyzed using 3-way ANOVA and Tukey's post-hoc test (p=0.05). Results: No significant difference in DC or Rpmax was observed between the 1 mm or 2 mm thick specimens when RE values were delivered by Optilux 501 or when the 1 mm thick composites were exposed to light emitted by Bluephase G2, which in turn promoted a lower DC when 18 J/cm2 (13 s) were delivered to the 2 mm thick specimens. Radii Plus promoted DC and Rpmax values close to zero under most conditions, while the delivery of 56 J/cm2 (40 s) resulted in low DC values. Conclusions: The third generation LCU provided an optimal polymerization of Lucirin TPO-based RC under most tested conditions, whereas the second generation LED-curing unit was useless regardless of the RE.


Assuntos
Resinas Compostas/efeitos da radiação , Luzes de Cura Dentária , Cura Luminosa de Adesivos Dentários/métodos , Fosfinas/efeitos da radiação , Análise de Variância , Teste de Materiais , Transição de Fase , Fotoiniciadores Dentários/química , Polimerização/efeitos da radiação , Doses de Radiação , Valores de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo
5.
J. appl. oral sci ; 25(2): 140-146, Mar.-Apr. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-841182

RESUMO

Abstract Alternative photoinitiators with different absorption wavelengths have been used in resin composites (RCs), so it is crucial to evaluate the effectiveness of light-curing units (LCUs) on these products. Objective Using Fourier transform infrared analysis (FTIR) in vitro, the effects of varying radiant exposure (RE) values generated by second and third generation LED LCUs on the degree of conversion (DC) and maximum rate of polymerization (Rpmax) of an experimental Lucirin TPO-based RC were evaluated. Material and Methods 1 mm or 2 mm thick silicon molds were positioned on a horizontal attenuated total reflectance (ATR) unit attached to an infrared spectroscope. The RC was inserted into the molds and exposed to varying REs (18, 36 and 56 J/cm2) using second (Radii Plus, SDI) and third generation LED LCUs (Bluephase G2/Ivoclar Vivadent) or a quartz tungsten based LCU (Optilux 501/SDS Kerr). FTIR spectra (n=7) were recorded for 10 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm-1) immediately after their application to the ATR. The DC was calculated using standard techniques for observing changes in aliphatic to aromatic peak ratios both prior to, and 10 min after curing, as well as during each 1 second interval. DC and Rpmax data were analyzed using 3-way ANOVA and Tukey’s post-hoc test (p=0.05). Results No significant difference in DC or Rpmax was observed between the 1 mm or 2 mm thick specimens when RE values were delivered by Optilux 501 or when the 1 mm thick composites were exposed to light emitted by Bluephase G2, which in turn promoted a lower DC when 18 J/cm2 (13 s) were delivered to the 2 mm thick specimens. Radii Plus promoted DC and Rpmax values close to zero under most conditions, while the delivery of 56 J/cm2 (40 s) resulted in low DC values. Conclusions The third generation LCU provided an optimal polymerization of Lucirin TPO-based RC under most tested conditions, whereas the second generation LED-curing unit was useless regardless of the RE.


Assuntos
Fosfinas/efeitos da radiação , Resinas Compostas/efeitos da radiação , Cura Luminosa de Adesivos Dentários/métodos , Luzes de Cura Dentária , Doses de Radiação , Valores de Referência , Fatores de Tempo , Teste de Materiais , Reprodutibilidade dos Testes , Análise de Variância , Espectroscopia de Infravermelho com Transformada de Fourier , Transição de Fase , Fotoiniciadores Dentários/química , Polimerização/efeitos da radiação
6.
Rev. ABENO ; 9(1): 34-38, 2009. ilus, tab
Artigo em Português | LILACS, BBO - Odontologia | ID: biblio-875011

RESUMO

O avanço científico que vem ocorrendo no Brasil elevou a necessitada de discussão sobre ética em pesquisa envolvendo seres humanos dentro das instituições de ensino superior. Para isso, a associação entre a arte persuasiva do cinema e a ética em pesquisa tem sido uma metodologia eficaz no que diz respeito ao processo de ensino-aprendizagem de alunos de graduação e pós-graduação. Assim, o objetivo deste projeto de extensão foi promover a discussão e o conhecimento sobre a ética em pesquisa envolvendo seres humanos com graduandos, pós-graduandos, professores e servidores públicos da Universidade Estadual de Ponta Grossa. Os resultados mostraram a efetividade do método, concluindo que os filmes contribuíram satisfatoriamente para o aprendizado e posicionamento ético de todos os participantes (AU).


The scientific advance that has occurred in Brazil increases the need to discuss ethics in human research within universities and research institutes. With this in mind, the association between the persuasive art of cinema and ethics research has been an effective methodology regarding the teaching and learning of undergraduate and graduate students. The aim of this extramural education project was to promote the discussion and understanding of ethics in human clinical research among undergraduate and graduate students, professors and public servants at Ponta Grossa State University. The results showed the effectiveness of this method. In conclusion, movies can contribute satisfactorily to the ethical learning and positioning of all participants (AU).


Assuntos
Humanos , Bioética/educação , Educação Superior , Ética em Pesquisa/educação , /estatística & dados numéricos , Brasil , Inquéritos e Questionários/estatística & dados numéricos
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