Comparison of primary human gingival fibroblasts from an older and a young donor on the evaluation of cytotoxicity of denture adhesives

Abstract Denture adhesives (DA) improve the retention and stability of ill-fitting dentures, especially for older adults. These materials should be biocompatible, i.e., they cannot cause undesired biological responses and be non-cytotoxic to oral tissues. However, in vitro testing of DA biocompatibility employing primary cell culture may possibly be affected by other factors, such as the donor age. Objective To compare the cytotoxicity of three different denture adhesives when assessed in primary gingival fibroblasts from a young donor or from an older donor, as well as the release of the basic fibroblast growth factor (bFGF), and the inflammatory response marker interleukin-6 (IL-6). Material and Methods Gingival fibroblasts isolated from a 30- and a 62-year-old donor were assayed for proliferation (1-7 days) and sensitivity to latex (positive control). Fibroblasts were indirectly exposed to Corega Ultra (cream), Corega powder and Fixodent Original for a 24 h period and assayed by XTT and Crystal Violet tests. The release of IL-6 and bFGF by exposed cells was determined by ELISA. Results While cells from the young donor presented higher cell growth after 7 days, the sensitivity to increasing concentrations of latex extracts was very similar between young and older cells. Both XTT and CVDE detected no difference between the DA and the control group. All materials induced higher levels of IL-6 and bFGF compared to control. Cells from the older donor exposed to Corega Ultra released lower levels of cytokine and growth factor. Conclusions All materials were considered non-cytotoxic, but affected cytokine and growth factor release. The biological differences found between fibroblasts from both donors could be due to individual or age-related factors. The authors suggest the use of cells from older donors on studies of dental products aimed at older patients, to better simulate their physiological response.

Influence of Photoinitiator System on Physical-Chemical Properties of Experimental Self-Adhesive Composites

Abstract The aim of this study was to determine the influence of photoinitiator systems on physical-chemical properties of flowable composites. Conventional (CFC), composed by bisphenol-glycidyl dimethacrylate (BisGMA)+triethyleneglycol dimethacrylate (TEGDMA), and self-adhesive (SAFC), composed by BisGMA+TEDGMA+bis{2-(methacryloyloxy) ethyl} phosphate (2MP), flowable composites were developed. Five photoinitiator systems were tested: camphorquinone (CQ), ethyl-4-dimethylaminobenzoate (EDMAB), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), phenylbis (2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), CQ+EDMAB+TPO and CQ+EDMAB+BAPO. A two-peak LED was used; degree of conversion (DC) and the maximum polymerization rate (RPmax) were determined by near infrared spectroscopy. For the yellowing degree a spectrophotometer was used. Water sorption (Wsp) was obtained after 30 days of water storage (n=5). Data were submitted to two-way analysis of variance and Tukey’s test (a=0.05). BAPO presented the highest DC and RPmax values for both series. SAFCs presented lower DC and RPmax for CQ+EDMAB-based materials. Greater yellowing was observed for SAFCs compared with CFCs, except for BAPO. Greater Wsp was observed for SAFCs compared with CFCs. The photoinitiator did not influence Wsp for CFCs, but TPO and BAPO presented the highest Wsp in SAFCs. The photoinitiator system affected differently the physical-chemical properties of CFCs and SAFCs.

Resumo O objetivo do estudo foi determinar a influência do sistema fotoiniciador sobre as propriedades físico-químicas de compósitos fluidos. Os compósitos convencionais foram compostos por bisfenol-glicidil dimetacrilato (BisGMA) + trietilenoglicol dimetacrilato (TEGDMA), e os autoadesivos, apresentavam BisGMA +TEGDMA+ Bis2(metacriloiloxi)etil fosfato (2 MP). Cinco sistemas fotoiniciadores foram testados: canforquinona + etil-4- dimetilamino benzoato (CQ+EDMAB), óxido mono-alquil fosfínico (TPO) e óxido bis-alquil fosfínico (BAPO), CQ+EDMAB+TPO e CQ+EDMAB+BAPO. LED de amplo espectro foi usado; o grau de conversão (GC) e a taxa de polimerização (TP) foram determinados por espectroscopia próximo ao infravermelho; o grau de amarelo foi mensurado por um espectrofotômetro e absorção de água foi obtida após 30 dias de armazenamento em água (n=5). Os dados foram submetidos a análise de variância de dois fatores e teste de Tukey (?=0,05). BAPO apresentou os maiores valores de GC e TP nos compósitos convencionais e autoadesivos. Compósitos autoadesivos apresentaram menor GC e TP quando CQ+EDMAB foi usado. Maior amarelecimento foi observado nos compósitos autoadesivos em relação aos convencionais, exceto para BAPO. Compósitos autoadesivos promoveram maior absorção de água. Não houve influência dos fotoiniciadores nos compósitos convencionais, no entanto TPO e BAPO apresentaram os maiores valores de absorção de água nos compósitos autoadesivos. Os sistemas fotoiniciadores influenciaram de maneira diferente as propriedades físico-químicas dos compósitos convencionais e autoadesivos.

Análise da passagem de luz visível através do cerômero e porcelana / Analysis of the transpiercing of the visible light thought resin composites and porcelain

Objetivo: analisar a quantidade de energia luminosa que chega ao material cimentante durante a polimerização de uma peça protética. Metodologia: Foram confeccionados corpos de prova padronizados de cerômero e de porcelana, que mediam 1,4 cm de diâmetro cada. Os corpos de prova foram divididos em grupos conforme a sua espessura (1mm ou 1,5mm) e o tipo de material. Foi utilizado um radiômetro para analisar a intensidade luminosa que atravessou a peça e os resultados obtidos foram expressos em mw/cm². Para todos os grupos, foi utilizada a distância de 3mm entre o aparelho fotopolimerizador e os corpos de prova. A padronização desta distância foi baseada nos resultados obtidos quando o aparelho fotopolimerizador foi apoiado diretamente sobre a célula fotossensível do radiômetro (distância 0mm) e obteve-se um resultado médio de 852,13 ± 18,022mw/cm² e quando o aparelho fotopolimerizador foi afastado a uma distância de 3mm e a média obtida foi de 671,37±37,869 mw/cm². Resultados: Os resultados mostraram que a média do grupo de porcelana, com 1mm de espessura, foi de 222,20 ± 22,048 mw/cm². O grupo do cerômero com 1mm de espessura apresentou uma média de 156,70 ± 12,009 mw/cm², a porcelana com 1,5mm de espessura, apresentou uma média de 139,03 ± 8,385 mw/cm². Já, o grupo cerômero com 1,5mm, absorveu completamente a luz. Conclusão: o grupo da porcelana, com 1 mm de espessura, permitiu que parte da energia luminosa chegasse ao material cimentante durante a polimerização e que a intensidade do aparelho fotopolimerizador e o tempo de exposição durante a cimentação protética devem ser ajustados conforme o tipo e a espessura do material utilizado.

Objective: this study to analyze the amount of luminous energy that arrived at the cimentante material during the polymerization of a prosthetic part. Methods: Standardized bodies of test of resin composites and porcelain had been confectioned and measured 1,4 cm of diameter each. The test bodies had been divided in groups in agreement its thickness (1mm and 1,5mm) and the type of material. A radiometer was used to analyze the luminous intensity that crossed the part and the gotten results had been express in mw/cm². Were used in the distance of 3mm between the photopolimerizer device and the bodies of test. The standardization of this distance was based on the gotten results when the photopolimerizer device was supported directly on the photosensitive cell of the radiometer (distance 0mm) and got 852.13 ± 18.022 mw/cm² an average result of and when the photopolimerizer device was moved away to a distance from 3mm, the average lowered for 671,37 ± 37,869 mw/cm². Results: The results had shown that the average of the group of porcelain, with 1mm of thickness, was of 222,20 ± 22,048 mw/cm². The group of resin composite of 1mm of thickness presented a average of 156,70 ± 12,009 mw/cm², the porcelain with 1,5mm presented a average of 139,03 ± 8,385 mw/cm². Already, the resin composite group of 1,5mm, absorbed the light completely. Conclusion: the group of the porcelain, with 1 mm of thickness, allowed that it has left of the luminous energy arrived at the cimentated material during the polymerization and that the intensity of the photopolimerizer device and the time of exposition during the prosthetic face-hardenings must be adjusted in agreement to the type and the thickness of the used material.

Principais técnicas de controle de comportamento em odontopediatria / Main techniques of behavior control in pediatric dentistry

Para lançar mão das principais técnicas de controle de comportamento na clínica odontopediátrica os profissionais devem ter conhecimento e embasamento suficientes para discernir dentre as técnicas, qual é a mais importante para cada paciente. O objetivo deste trabalho foi, por meio de uma revisão da literatura, descrever e discutir as principais técnicas para controle de comportamento, destacando as técnicas: controle pela voz, falar-mostrar-fazer, e mão sobre a boca.