Roselaine Terezinha Pozzobon

Intensidade de fluorescência em resina composta: influência do polimento superficial e dos meios de armazenagem

INTRODUCTION: Resin composite is a versatile material in cosmetic dentistry due mainly to its optical properties, fluorescence among them. There are a few studies which assessed such property and a comparison of results becomes difficult due to the lack of a pattern in the specimens storage and confection methodologies. OBJECTIVE: Verify the influence of superficial polishing and means of storage in in vitro studies that assess the optical property of fluorescence in dental resin composites. MATERIAL AND METHOD: 70 circular specimens (10 mm × 2 mm) were prepared with microhybrid composite resin (Opallis, - A2E - FGM). The means of storage were: deionized water, tap water and artificial saliva. The superficial polishing protocols used 600, 1200 and 2500 sandpaper grit sizes, accomplished with polisher after specimens were obtained. The fluorescence intensity values were assessed using Cary Eclipse Fluorescence Spectrophotometer after 1, 7 and 21 days. RESULT: There was not a statistically significant difference in Fluorescence Intensity among the groups submitted to the different polishing protocols. Concerning the means of storage, from the seventh day on the fluorescence variation was significantly bigger in tap and deionized water, compared to artificial saliva, such result kept on after 21 days. CONCLUSION: the superficial polishing protocol did not promote significant changes in the assessed resin composite fluorescence. Regarding the means of storage, the fluorescence intensity was less affected when in artificial saliva.

Avaliação do potencial cariogênico de medicamentos pediátricos

O objetivo desta pesquisa foi avaliar o potencial cariogenico de seis medicamentos pediatricos atraves da verificacao dos edulcorantes presentes na formula, do potencial de causar xerostomia e da frequencia de ingestao, pesquisados na bula dos medicamentos. Foi tambem verificado o pH endogeno das medicacoes atraves do pHmetro Quimis, modelo Q 400-A. As medicacoes selecionadas para avaliacao foram aquelas mais citadas em pesquisa previa realizada nas Clinicas de Odontopediatria da UFSM. Foi verificado que a maior parte das medicacoes avaliadas continham sacarose em sua composicao e o pH endogeno de todos os medicamentos foi acido, sendo inferior ao pH critico para desmineralizacao do esmalte em 2/3 deles. O unico medicamento encontrado com potencial de causar xerostomia foi o Claritin.

Ion release from a composite resin after exposure to different 10% carbamide peroxide bleaching agents

Objective This in vitro study evaluated the influence of two 10% carbamide peroxide bleaching agents - a commercial product (Opalescence PF; Ultradent Products, Inc.) and a bleaching agent prepared in a compounding pharmacy - on the chemical degradation of a light-activated composite resin by determining its release of ions before and after exposure to the agents. Material and Methods Thirty composite resin (Filtek Z250; 3M/ESPE) samples were divided into three groups: group I (exposed to Opalescence PF commercial bleaching agent), group II (exposed to a compounded bleaching agent) and group III (control - Milli-Q water). After 14 days of exposure, with a protocol of 8 h of daily exposure to the bleaching agents and 16 h of immersion in Milli-Q water, the analysis of ion release was carried out using a HP 8453 spectrophotometer. The values were analyzed statistically by ANOVA, Tukeys test and the paired t-tests. The significance level was set at 5%. Results After 14 days of the experiment, statistically significant difference was found between group II and groups I and III, with greater ion release from the composite resin in group II. Conclusions The compounded bleaching agent had a more aggressive effect on the composite resin after 14 days of exposure than the commercial product and the control (no bleaching).

Evaluation of the surface roughness of a nanofilled composite resin submitted to different smoothing and finishing techniques

Introduction: Controlling the surface smoothness characteristics of the composite resin when performing a direct restorative technique is one of the factors involved in achieving restorative success. Objective: The purpose of this study was to evaluate the surface roughness of a nanofilled composite resin submitted to different smoothing and finishing techniques. Material and method: Fifty test specimens were made with the Z350 XT composite resin (3M ESPE) and then divided into five study groups according to the smoothing and finishing method applied, as follows: G1 (control), polyester strip; G2, composite spatula; G3, brush cleaned with absolute alcohol and dried; G4, brush cleaned with absolute alcohol, dried and moistened with Single Bond (3M ESPE); and G5, brush cleaned with absolute alcohol, dried and moistened with Natural Glaze surface sealant (DFL). After fabrication, the specimens were stored for 24 h in deionized water. The surface roughness of the specimens was measured using a profilometer. Surface roughness means were compared by analysis of variance followed by Tukey’s test at a level of significance of 5%. Result: The lowest surface roughness was observed in G1 (control group) and the highest, in G3. G5 had lower surface roughness values compared to the other test groups, and presented values similar to those of the control group. Conclusion: The smoothing and finishing techniques influenced the surface roughness of the composite resin. Application of the surface sealant by the copolymerization technique resulted in lower roughness values. The use of a clean, dry brush promoted roughness values beyond the acceptable limit, and is therefore liable to compromise the performance of composite resin restorations.

AVALIAÇÃO DO PH DE REFRIGERANTES DO TIPO NORMAL E LIGHT

O objetivo foi determinar o pH de refrigerantes e comparar os valores do grupo normal com os valores do grupo light. Para a comparacao foi realizada a medicao do pH dos refrigerantes atraves de um pHmetro calibrado. Cada liquido teve seu pH medido 05 vezes consecutivas com um intervalo de tres minutos entre cada medicao, os valores encontrados foram submetidos a analise estatistica. Os valores encontrados foram: Coca-cola pH= 1,78, Coca-cola Light pH= 2,36, Guarana Kuat pH= 1,82, guarana Kuat Light pH= 1,87, Sprite pH= 1,92, Sprite Zero pH= 1,86, Fanta Laranja pH= 2,22, Fanta laranja light pH=2,62. A Coca-cola, guarana, Sprite, Sprite zero e guarana light apresentaram maior potencial erosivo, Coca-cola light e Fanta laranja light apresentaram menor potencial erosivo e Fanta laranja apresentou potencial erosivo intermediario. Dentro da amostra a coca - cola e a fanta laranja apresentaram maior potenci al erosivo do que seus correspondentes light. Palavras-Chave: Erosao dentaria, bebidas gasosas, esmalte dentario