Academic literature on the topic 'Bevel cavosurface angle composite resins'

<p><span>he aim of this In Vivo study was to evaluate the influence of the cavosurface angle (with bevel, and no preparation), of direct composite resin restorations in previous fractured teeth after 4 years of clinical performance. The restorations were performed by a single operator, following a restorative standardized protocol. For the study were selected 24 upper central incisors with fracture or with class IV restorations with an indication of replacement. According to the restorative technique, the teeth were divided into 2 groups: group I (n = 12) Class IV Restorations with a bevel preparation technique; and group II (n = 12) Class IV Restorations performed with no preparation. The restorations were evaluated at 7 days and 4 years, by two examiners, previously calibrated using modified USPHS criteria. After 4 years, two restorations were excluded, representing 22 restorations (11 with bevel preparation, and 11 without). The Fisher test demonstrates no significant differences between groups (p &gt; 0.05). This study presents clinical evidence that the cavosurface angle configuration does not influence the clinical performance of direct composite resin restorations in fractured teeth. Thus, we recommend no preparation of the cavosurface angle to preserve sound dental tissue based on a Minimally Invasive Dentistry approach. </span></p>

SUMMARY Objective This study evaluated the effect of quantity of resin composite, C-factor, and geometry in Class V restorations on shrinkage stress after bulk fill insertion of resin using two-dimensional finite element analysis. Methods An image of a buccolingual longitudinal plane in the middle of an upper first premolar and supporting tissues was used for modeling 10 groups: cylindrical cavity, erosion, and abfraction lesions with the same C-factor (1.57), a second cylindrical cavity and abfraction lesion with the same quantity of resin (QR) as the erosion lesion, and then all repeated with a bevel on the occlusal cavosurface angle. The 10 groups were imported into Ansys 13.0 for two-dimensional finite element analysis. The mesh was built with 30,000 triangle and square elements of 0.1 mm in length for all the models. All materials were considered isotropic, homogeneous, elastic, and linear, and the resin composite shrinkage was simulated by thermal analogy. The maximum principal (MPS) and von Mises stresses (VMS) were analyzed for comparing the behavior of the groups. Results Different values of angles for the cavosurface margin in enamel and dentin were obtained for all groups and the higher the angle, the lower the stress concentration. When the groups with the same C-factor and QR were compared, the erosion shape cavity showed the highest MPS and VMS values, and abfraction shape, the lowest. A cavosurface bevel decreased the stress values on the occlusal margin. The geometry factor overcame the effects of C-factor and QR in some situations. Conclusion Within the limitations of the current methodology, it is possible to conclude that the combination of all variables studied influences the stress, but the geometry is the most important factor to be considered by the operator.

This study was carried out to study a restorative technique of 2 mm thickness of composite resin filling material that bonded, by adhesive (4-META), to MOD cavities (Mesial, Occlusal and Distal surfaces of a tooth) partially filled with amalgam filling materials in upper premolars on the fracture resistance when compared to a sound tooth. Forty freshly sound extracted upper premolars were divided into four groups: the first group of ten sound premolars is subjected to fracture resistance test, the second group of ten premolars with a MOD of half intercuspal distance cavities, which was prepared with long bevel at the cavosurface angle and the teeth were filled with composite resin following incremental technique. The third group of ten teeth were prepared with a box form and butt joint of the same MOD cavities dimension and filled with non-gamma II amalgam. The fourth group of ten premolars with the same MOD cavities dimension are filled with amalgam, a 2 mm thickness of amalgam was removed of the occlusal surface after 24 hours, extended proximally mesially and distally, etch of the exposed enamel, dentin and amalgam was performed, and 4-META adhesive was applied to amalgam and exposed dentin and enamel followed by posterior composite bonded to tooth and amalgam, and cured with light for 40 seconds. The teeth of all groups were tested for fracture resistance. The group I showed the highest resistance to fracture followed by group IV followed by group II and lastly, group III. This study concluded that the use of combined bonded amalgam-composite and tooth structure provided the best technique for filling than cavity only filled with composite or amalgam.

Abstract Introduction To prevent the shrinkage stresses produced during polymerization, composite resins of low polymerization shrinkage were developed. Objective To evaluate the microtensile bond strength in class I cavities restored by acid-etching the cavosurface angle and with composite resins indicated for posterior teeth. Material and method 48 healthy molars were selected and divided into six groups (n = 8), considering that the cavosurface enamel of three groups was etched with 35% phosphoric acid. The teeth were restored with the Clearfil SE Bond adhesive system and Filtek Z350 XT, Empress Direct, and Charisma Diamond composite resins, which were light-cured for 40 seconds. After 24 hours, the teeth were taken to a cutting machine, which produced sections in the buccolingual and mesiodistal directions. This resulted in toothpicks of 0.9×0.9 mm that were taken to the universal testing machine for the microtensile bond strength test. Statistical analysis was performed with ANOVA and Tukey’s test (p < 0.05). Result There was no statistically significant difference between the groups evaluated. Conclusion Acid-etching the cavosurface angle did not affect the performance of restorations, probably due to the adhesive system used.

A estética dentária é um tema complexo, dependente de múltiplos fatores e aumenta cada vez mais a importância dada quer pelos pacientes quer pelos profissionais na tentativa de satisfazer ou superar as expectativas. O presente estudo pretende avaliar a importância do bisel do ângulo cavo-superficial no preparo cavitário de cavidades de classe IV em restaurações estéticas com resinas compostas. Mais especificamente, objetiva-se: i) avaliar quantitativamente as propriedades óticas de restaurações em compósito em que o ângulo cavo-superficial foi biselado durante o preparo cavitário; ii) avaliar quantitativamente as propriedades óticas de restaurações em compósito em que o ângulo cavo-superficial não foi biselado durante o preparo cavitário; iii) comparar os resultados obtidos nos objetivos anteriores para determinar quantitativamente qual a relevância do bisel no ângulo cavo-superficial de restaurações em compósito de cavidades de classe IV. Trata-se de um estudo observacional e prospetivo de resultados obtidos em peças dentárias através do Espectrofotómetro Jasco V-560 (500 a 300 nm, resolução até 0,1 nm) com monocromador duplo e esfera integradora para análise de sólidos através de reflexão difusa (300-500 nm), disponibilizado pelo Departamento de Química da Universidade de Aveiro. Em estudos anteriores aponta-se para que o bisel confira uma vantagem estética quando executado em cavidades de classe IV em dentes anteriores. Todavia, não foi possível com este estudo, definir qual o tipo de vantagem estética que o bisel confere, uma vez que quando analisado, este mostrou evidências significativas apenas na zona ultravioleta do espectro de reflexão. As características estéticas até hoje estudadas, foram apenas evidenciadas na zona visível do espectro de reflexão, deixando assim uma incógnita relativamente ao modo de interpretação dos resultados obtidos no presente estudo, no campo das características estéticas. A Medicina Dentária Restauradora, visa garantir o aspeto mais natural possível à restauração efetuada, no entanto, as vantagens estéticas são muito complexas de ser quantificadas e o presente estudo objetivava exatamente isso, no entanto não foi possível quantificar essa diferença, porquanto se trata de um tema significativamente subjetivo.
The dentistry aesthetic is a complex issue that depends on multiple factors and increasingly increases the importance given either by patients or by professionals in an attempt to meet or exceed expectations. The aim of this study was to evaluate the importance of the bezel cavosurface angle in the cavity preparation of class IV cavities in esthetic restorations with composite resins. More specifically, the objective is to: i) quantitatively evaluate the optical properties of composite restorations in the cavosurface angle was beveled during cavity preparation; ii) quantitatively assess the optical properties of composite restorations in the cavosurface angle was left intact during cavity preparation; iii) to compare the results obtained in previous objectives to quantitatively determine the relevance of the bevel on cavosurface angle restorations of class IV cavities composite; iv) make a review of current literature on the subject under discussion. This is an observational and prospective study results of dental pieces by Jasco V-560 spectrophotometer 500-300 nm to 0.1 nm resolution) with double monochromator, integrating sphere for analysis by diffuse reflection solid (300-500 nm) of the Department of Chemistry at the University of Aveiro. It was concluded that the bezel provides an aesthetic advantage when running in class IV cavities in anterior teeth. However, it was not possible to define the type of aesthetic advantage, which can be seen in the reflection spectrum in the ultraviolet region, which is the area where you can check the actual existence and the advantage of cavosurface beveled angle. The aesthetic advantages are too complex to be defined, because it is a significantly subjective topic. Taking into account that objective in Restorative Dentistry, ensure the most natural look possible the restoration done, it can be stated that, based on the results obtained, the bevel gives the advantage to that level.