Influence of the Light Source and Curing Parameters on Microhardness of a Silorane-Based Dental Composite Material

Archives of Materials Science and Engineering

Paluch

Sobolewska

et al. 2016

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Purpose: The aim of the study was to examine the connection between the zirconia substructure and the porcelain in the dental crowns subjected to simulated occlusal forces. Design/methodology/approach: All-ceramic dental crowns were subjected to Vickers hardness examination, testing of compressive strength and observations of breakthroughs on the SEM. Findings: Based on the research, it was found that the compressive force at which ceramic crowns brake down, are in the range of maximum occlusal loads exerted by man. There is a mechanical connection between zirconia and porcelain. All-ceramic crowns of premolars showed the highest resistance to compressive force, while the crowns of canines are characterized by the lowest resistance to the loading force. In addition, through the research we found that ceramic crowns under static compressive loads brake down and the fracture line runs through the entire thickness of the wall, because zirconium oxide has more than twice the hardness of the porcelain. There is a difference of stresses between the materials, causing fracture of the restoration. Practical implications: The research work shows that the porcelain crowns on the substructure of zirconia (all-ceramic restoration) are a very good option of the restorative treatment in dentistry, rebuilding missing teeth. Originality/value: The article presents a study on the compressive strength of manufactured crowns, followed by a comparison to the natural forces of occlussion in human. The exact mapped tooth geometry and the appropriate veneering porcelain foundation of zirconium allows the use of prosthetic crowns in the patient's mouth without fear that porcelain will be broken.

Section: Discussionmentioning

confidence: 99%

The study of the connection between the zirconia substructure and veneering porcelain in dental crowns subjected to occlusal forces

Archives of Materials Science and Engineering

Paluch

Sobolewska

et al. 2016

Self Cite

“…These newer LED lights have been shown to have produced material properties similar to QTH lights [7,8]. Moreover, several publications have highlighted the potential of these lights as reducing irradiation time without a significant loss of mechanical properties [7,[9][10][11][12][13][14]. In contrast with QTHs, LEDs do not need filters to diminish the infrared energy flux.…”

Section: Introductionmentioning

confidence: 99%

Temperature changes influenced by different types of light curing units during polymerization of resin-based dental composite materials

Archives of Materials Science and Engineering

Świderski²,

Świderska³

2016

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Purpose: of this study was to evaluate the influence of LCU type on temperature changes during polymerization of two resin-based composites with different matrices (silorane-based and methacrylate-based).Design/methodology/approach: The light-curing units (LCUs) selected for this study included three various LEDs (LED 55, LED 10W and Radii Plus) and a QTH (Elipar Highlight). Two different resin-based composites (RBCs) were used in this study. The silorane-based composite Filtek Silorane and methacrylate-based composite Filtek P60. Temperature changes were measured during polymerization with LCUs working in various curing modes. Empty mold, Filtek Silorane RBC and Filtek P60 RBC were cured from a distance of 0 mm, 2.5 mm and 5 mm. Research limitations/implications: The research was carried out for two groups of composite materials used for teeth restoration in modern dentistry. The experiment should be repeated on a broader group of resin-based composite dental materials and should take into account more light-curing units. The study could be also done in situ on a real tooth model. Practical implications:This research gives an insight into the range of temperatures that are generated during polymerization process of dental composite materials. The results of the study are of a great value during choosing the restorative composite material for particular application in the oral cavity, selecting the right light-curing-unit and adjusting the curing parameters Originality/value: The results of the study allow to conclude that the temperature values vary for each resin-based material, according to light-curing-unit type and the distance of curing seemed to have least influence on temperature changes during polymerization.----- 65READING DIRECT: www.archivesmse.org

Assessment of the compressive strength of the metal-ceramic connections in fixed dental restorations

Journal of Achievements in Materials and Manufacturing Engineering

Paluch

Sobolewska

et al. 2016

Purpose: The purpose of the work was to evaluate the compressive strength of metalceramicconnections in the fixed dental restorations.Design/methodology/approach: Restorations were made on a model of the naturalpatient's dentition which was developed specifically for this study. The study included 10metal - porcelain crowns, for each group of teeth. Their production used Remanium 2000+alloy and porcelain Vita VMK Master. A static compression test was carried out on the finalcrowns and Vicker's hardness test was performed. Visual observations were carried out ona scanning electron microscope.Findings: On the basis of the research and the discussion it was possible to concludethat metal-porcelain crowns have a greater compressive strength than natural human teeth.Thus, they are more resistant to occlusal forces and the crowns for the first molars are thestrongest restorations.Practical implications: The metal-porcelain crowns are a very good option for teethrestoration and they can be used even in the areas of the mouth where the occlusal forcesreach the maximum values.Originality/value: The article focuses on testing of compressive strength of metal-ceramiccrowns. The comparison with natural human occlusal forces shows the sufficient mechanicalproperties of metal-ceramic crowns for application in humans. The artificial tooth geometryallows applying prosthetic crowns in the patient's mouth without the risk of ceramic breakdown.