The effect of storage temperature and application temperature on the properties of adhesives and resin composites / 口腔疾病防治

@#The properties of adhesives and light-cured resin composites are closely related to the repair of dental defects. Therefore, improving the properties of adhesives and resins composite to increase the success rate of filling has been the focus of research in the field of prosthodontics in recent years. Current studies have confirmed that temperature can change the properties of adhesives and light-cured resin composites, affecting their repair effect. A proper storage temperature ensures the good performance of materials: the self-etching adhesive system should be refrigerated, and the light-cured resin composite should be refrigerated or stored at room temperature according to its composition, proportion and other properties; however, the appropriate storage temperature for the etch-and-rinse adhesive system is not clear. The appropriate application temperature could improve the fluidity, monomer conversion, bonding strength, compressive strength and other properties of the materials to improve the quality of filling restoration. However, there is a wide variety of adhesives and resin composites, and the effect of temperature on each material is different. Thus, it is still necessary to explore the temperature range for material storage, precooling and preheating. Few studies have been performed in vivo, and the clinical restorative effects of adhesives and resin composites stored and used at different temperatures need to be further studied.

Translucency,opalescence and fluorescence properties of six light-cured resin composites / 实用口腔医学杂志

Objective:To evaluate the translucency,opalescence and fluorescence reflection of 6 light-cured resin composites. Methods:Disks of 6 resin composites including Filtek Supreme XT-YT(XT),Filtek Supreme XT-A3B(3M),Clearfil Majesty-A3 (MJ),Gradia Direct-A3(GC),Venus-A3(VE)and Charisma Diamond-A3(CA)were prepared in the diameter of 9 mm with the thickness 2.0 mm.PR-650 spectral scanning colorimeter was used to measure and caculate translucency parameters(TP),opal-escence parameter(OP)and fluorescence reflection(FL)and to draw the fluorescence reflection curves.Results:Except XT and MJ,TP value of other resin composites were in the range of natural tooth.Only OP value of XT was in the range of natural tooth en-amel.FL value of XT was close to that of natural tooth dentin.Fluorescent peak wavelength of GC,MJ,VE and CA were in the range of natural tooth,but fluorescent peak height was higher than that of natual tooth.TP was positively correlated with OP(r =0.85,P <0.05).There was no statistic correlation between TP and FL,between OP and FL.Conclusion:The 6 resin composites can simulate optical property of natual tooth,but the opalescence of resin composites is defective.

Effect of four-handed technique in light cured resin veneer in the treatment of dental fluorosis / 现代临床护理

Objective To observe the effect of four-handed technique in light cured resin veneer in the treatment of dental fluorosis. Methods Eighty outpatients with dental fluorosis in our hospital from January 2011 to January 2014 were randomly divided into two groups: 40 in the study group were treated with four-handed technique and another 40 in the control group with one-doctor manual operation. The two groups were compared in terms of treatment duration and curative effect. Result The treatment duration in the study was significantly shorter than that of the control group and the curative effect was significantly better than that of the control group (all P<0.05). Conclusion As for the light cured resin veneer in the treatment of patients with dentalfluorosis in the process , the four-handed technique is better than one-doctor manual operation.

Degree of Conversion of a Resin Cement Light-Cured Through Ceramic Veneers of Different Thicknesses and Types

During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (high translucency) - Ivoclar Vivadent] of four thicknesses (0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm). As control, the cement was light-cured without interposition of ceramics. The degree of conversion was evaluated by FTIR spectroscopy (n=5). Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). Significant differences were observed among groups (p<0.001). The degree of conversion was similar to the control for all light-cured groups with interposition of ceramics of 0.5 mm and 1.0 mm (p>0.05). Among 1.5-mm-thick veneers, IPS e.max LT was the only one that showed different results from the control (p<0.05). At the thickness of 2.0 mm, only the IPS e.max LT and HT veneers were able to produce cements with degrees of conversion similar to the control (p>0.05). The degree of conversion of the evaluated light-cured resin cement depends on the thickness and type of ceramics employed when veneers thicker than 1.5 mm are cemented.

Durante a cimentação de facetas cerâmicas, a polimerização de cimentos resinosos pode ser comprometida se a cerâmica atenuar a irradiância do aparelho fotopolimerizador. O objetivo deste estudo foi avaliar o efeito de diferentes tipos e espessuras de facetas cerâmicas sobre o grau de conversão de um cimento resinoso fotopolimerizável (RelyX Veneer). O cimento foi fotoativado após a interposição de facetas cerâmicas [IPS InLine, IPS Empress Esthetic, IPS e.max LT (baixa translucidez) e IPS e.max HT (alta translucidez) - Ivoclar Vivadent] de quatro espessuras (0,5 mm; 1,0 mm; 1,5 mm e 2,0 mm). Como controle, o cimento foi polimerizado sem interposição de cerâmica. O grau de conversão foi avaliado por espectroscopia FTIR (n=5). Os dados foram analisados através de ANOVA a um critério e teste de Tukey (α=0,05). Foram observadas diferenças significativas entre os grupos (p<0,001). O grau de conversão foi semelhante ao do controle para todos os grupos polimerizados com interposição de cerâmicas de 0,5 mm e 1,0 mm (p>0,05). Entre as facetas de 1,5 mm de espessura, IPS e.max LT foi a única que apresentou resultados diferentes do controle (p<0,05). Com a espessura de 2,0 mm, apenas IPS e.max LT e HT foram capazes de produzir cimentos com grau de conversão semelhantes aos do controle (p>0,05). O grau de conversão do cimento resinoso fotopolimerizável avaliado depende da espessura e do tipo de cerâmica utilizados quando facetas mais espessas do que 1,5 mm são cimentadas.

Use of light-cured resin to manufacture occlusal splints: report of two cases

This article presents selected cases of patients with functional disorders of the stomatognathic system. This group of patients had a need to made different types of removable occlusal splints. In the past, occlusal appliances were made mostly using self-cured acrylate materials, which for many years had no replacements. The rapid development of dental materials technology led to creation of thermo-formable materials and resins, which can successfully replace traditional acrylic materials in daily clinical practice. A practical application of light-cured resin in the fabrication of the occlusal splints in two clinical cases is reported and discussed herein.

Este artigo apresenta casos selecionados de pacientes com distúrbios funcionais do sistema estomatognático, que necessitavam de diferentes tipos de placas oclusais removíveis. No passado, as placas oclusais eram fabricadas, em sua maioria, utilizando-se materiais acrílicos autopolimerizáveis, sem que houvesse substituto por muitos anos. O rápido desenvolvimento da tecnologia dos materiais odontológicos levou ao desenvolvimento de materiais termo-moldáveis e resinas, os quais podem substituir os tradicionais materiais acrílicos com sucesso na prática clínica diária. A aplicação prática da resina fotopolimerizável na fabricação de placas oclusais em dois casos clínicos é relatada e discutida neste trabalho.

Shear bond strength and failure patterns according to the material of resin base in indirect racket bonding / 대한치과교정학회지

The purpose of this study was to evaluate the propriety of making use of the light-cured resin base in indirect bracket bonding technique by study of shear bond strength and failure patterns according to the material of resin base. Metal brackets were bonded to the stone models of specimens involving bovine lower incisor with chemical-cured(Excel), light-cured(Light-Bond) and thermal-cured(Therma-Cure) resin. They were transferred to the specimens and bonded using sealant. The shear bond strength was tested on Instron. After bracket removal, the bracket base was examined and assessed with the adhesive remnant index(ARI). The results were as follows: 1. No significant differences in shear bond strength were found among the three groups (P>0.05). 2. No significant differences in Alts score were found among the three groups (P>0.05). The above results suggest that light-cured resin base in addition to chemical-cured and thermal-cured resin bases is useful in the indirect bonding technique.

Effects of chemically cured resin and light cured resin on shear bond strength of metal bracket and ceramic bracket / 대한치과교정학회지

This study was designed for comparison of shear bond strengths and failure patterns of four experimental groups which combinated mesh-backed metal brackets and texture based ceramic brackets (Transcend series 2000((TM))) with chemically cured resin (Mono Lok2((TM))) and visible light cured resin (Transbond((TM))). Brackets were bonded on the extracted human bicuspids, after etching them by manufacturer's recommand, and the shear bond strengths were measured on the Instron machine after 24 hrs passed in the 37degrees C water bath. The results were as follows. 1. Ceramic brackets, transcend series 2000((TM)), bonded with MonoLok2((TM)) showed statistically higher shear bond strength than mesh-backed metal brackets bonded with MonoLok2((TM)). 2. There was no significant difference in shear bond strengths between metal and ceramic brackets bonded with Transbond((TM)). 3. Ceramic brackets bonded with both Transbond((TM)) and MonoLok2((TM)) showed primarily fractures bet?ween brackets adhesive interface. 4. Enamel crack was not found in anyone specimen.