Knoop microhardness and FT-Raman evaluation of composite resins: influence of opacity and photoactivation source

Albino, Luis Gustavo Barrotte; Rodrigues, José Augusto; Kawano, Yoshio; Cassoni, Alessandra

doi:10.1590/s1806-83242011000300013

Cited by 18 publications

(8 citation statements)

References 20 publications

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“…The spectra were processed with FORAM PC‐software. The DC calculations were performed by comparing the relative change of the band at 1640 cm −1 , representing the C = C stretch to the aromatic C = C reference band peak height at 1610 cm −1 , which remained unchanged during the reaction as described in the following equation:

normalD normalC % = (|, 1 - \frac{normalc normalu normalr normale normald (|, normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1640 / normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1610)}{normalu normaln normalc normalu normalr normale normald true(normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1640 / normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1610 true)}) \times 100

…”

Section: Methodssupporting

confidence: 79%

Degree of conversion and cross‐link density within a resin‐matrix composite

et al. 2017

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The aims of this study were to profile light radiated from two light-curing units (LCUs) and evaluate profile relationship to polymerization patterns within a resin-matrix composite (RMC). Beam profiles of one multiple emission peak light-emitting-diode and one quartz-tungsten-halogen curing-unit were measured using a beam profiler/spectrometer system. A camera-based profiler and an integrating sphere/spectrometer assembly were used to evaluate each LCU beam. Polymerization patterns within a nano-hybrid RMC were investigated using a mapping approach by assessing the degree of conversion utilizing micro-Raman spectroscopy and indirectly estimating cross-link-density by repeated microhardness testing before and after exposure to ethanol (%KH reduction, n = 3). The irradiance received on the top and bottom specimen surfaces from both LCUs was measured using a MARC-RC system. The investigated beam profile area from both LCUs was non-uniform and yielded localized discrepancies in DC (55.7-74.9%) and %KH reduction (26.7-54.1%). The LCU irradiance received at the bottom of the specimens was ∼10% of the top value. This study demonstrated that LCU beam profiles were non-uniform in the area explored. Localized differences in DC and %KH reduction existed throughout the RMC specimens but did not follow a specific pattern. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1496-1504, 2018.

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normalD normalC % = (|, 1 - \frac{normalc normalu normalr normale normald (|, normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1640 / normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1610)}{normalu normaln normalc normalu normalr normale normald true(normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1640 / normalp normale normala normalk normalh normale normali normalg normalh normalt normalu normaln normald normale normalr 1610 true)}) \times 100

…”

Section: Methodssupporting

confidence: 79%

Degree of conversion and cross‐link density within a resin‐matrix composite

et al. 2017

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“…The rate of cure of RBCs is affected by their shade and translucency, because these optical properties interfere with light transmission. For example, Filtek Supreme XT Translucent showed a higher rate of cure than the Dentin and Enamel shades 17) . Other factors that affect the rate of cure of RBCs include the type of light curing unit used (with different light intensity outputs and spectral distributions [18][19][20][21] ), irradiation time 21) , and distance from the curing light tip 19) .…”

Section: Introductionmentioning

confidence: 98%

Effects of aging and irradiation time on the properties of a highly translucent resin-based composite

Bauer

Ilie

2013

Dent. Mater. J.

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This study investigated the effects of aging and irradiation time on the macro-and micro-mechanical properties of a highly translucent nanohybrid composite (IPS Empress Direct, Trans Opal shade, Ivoclar Vivadent). Flexural strength, flexural modulus, indentation modulus, Vickers hardness, and creep were measured after being irradiated with different durations (5, 10, 20, and 40 s) and aged under different conditions (24 h at 37°C in water; 5,000 times of thermocycling between 5°C and 55°C followed by 4-week storage in artificial saliva or alcohol). Rate of cure was also measured for these four irradiation times at composite specimen surface and at 2 mm depth. Effects of aging and irradiation time were statistically analyzed using one-way ANOVA with Tukey's HSD post hoc test (α=0.05), partial eta-squared statistic, and Weibull analysis. Alcohol aging significantly reduced the mechanical properties. Aging in saliva produced a positive effect on micro-mechanical properties. Irradiation time should be at least 20 s to yield favorable mechanical properties.

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“…Um maior grau de conversão de um material resinoso estaria associado a um maior valor de dureza. Apesar dessa relação ser mais precisa em materiais de mesma composição monomérica e de carga, parece pertinente associar os resultados encontrados a diferenças no processo de polimerização das resinas compostas 10,12,13 . Exceção feita à Filtek P-90 ® , os compósitos avaliados apresentam semelhança de componentes monoméricos, que seriam um dos fatores importantes no processo de polimerização.…”

Section: Discussionunclassified

“…A resina escolhida deve apresentar opções de cores, facilidade de manipulação e de polimento, e adequadas propriedades mecânicas. Esse último fator é dependente do tipo de monômero resinoso utilizado 4,5 , da quantidade, do tipo de carga 6,7 , e do processo de polimerização 8,9 que deve proporcionar alto grau de conversão 10,11 , permitindo que a estrutura polimérica formada apresente uma adequada quantidade de ligações cruzadas 12,13 . A partir do desenvolvimento do monômero resinoso Bis-GMA (Bis-Fenol A di-Glicidil Metacrilato) por Bowen na década de 1960, foi possível a incorporação de carga aos compósitos odontológicos.…”

Section: Introductionunclassified

Avaliação da microdureza knoop e tração diametral de resinas compostas de uso direto

Marques

2014

Rev. da Fac. de Odontologia, UPF

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IntroduçãoO sucesso das restaurações de resina composta está associado, dentre outros fatores, à escolha adequada do material restaurador [1][2][3] . A resina escolhida deve apresentar opções de cores, facilidade de manipulação e de polimento, e adequadas propriedades mecânicas. Esse último fator é dependente do tipo de monômero resinoso utilizado 4,5 , da quantidade, do tipo de carga 6,7 , e do processo de polimerização 8,9 que deve proporcionar alto grau de conversão 10,11 , permitindo que a estrutura polimérica formada apresente uma adequada quantidade de ligações cruzadas 12,13 . A partir do desenvolvimento do monômero resinoso Bis-GMA (Bis-Fenol A di-Glicidil Metacrilato) por Bowen na década de 1960, foi possível a incorporação de carga aos compósitos odontológicos. Com isso houve grande avanço no desenvolvimento desses materiais e crescente aumento na sua utilização 14 . Diversos avanços foram realizados desde então, tanto na alteração dos monômeros como no desenvolvimento de cargas cada vez menores [14][15] . Das cargas de quartzo de grande tamanho utilizadas nos primeiros compósitos comerciais, evoluiu-se para cargas de tamanho nanométrico em resinas compostas atuais, melhorando a distribuição e a

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Knoop microhardness and FT-Raman evaluation of composite resins: influence of opacity and photoactivation source

Cited by 18 publications

References 20 publications

Degree of conversion and cross‐link density within a resin‐matrix composite

Degree of conversion and cross‐link density within a resin‐matrix composite

Effects of aging and irradiation time on the properties of a highly translucent resin-based composite

Avaliação da microdureza knoop e tração diametral de resinas compostas de uso direto

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