Dental restorative composites

Adhesion, filler/matrix adhesion, dimensional stability, reinforcement, and wear resistance are the most important concerns in the development of dental compos-ites. These requirements are shared with composites used for many other purposes. So much as the methods of testing, mathematical models, methods of interpretation, and remedies developed in other applications may be applied to dental composites. 

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Ultraviolet radiation-curable filled urethane dlmethacylate cements have been used as dental restorative compositions. ... 

Uses in dental restorative composite materials reactive monomer in adhesive products A... 

Synonyms BIS-MA 2-methyl-2-propenoic acid (i-methylethylidene)di-4,i-phenylene ester Bisphenol A dimethacrylate 4,4 -isopropylidenediphenol dimethacrylate Bisphenol a dimethacrylate, ethoxylated Uses in dental restorative composite and adhesive materials A... 

The major components of the adhesive compositions were stated to be three parts by weight of the BisGMA and one part by weight of methylmethacrylate monomer. In the foregoing BisGMA dental restorative compositions, the low molecular weight methylmethacrylate serves essentially as a reactive extender or diluent to reduce the viscosity of the compositions, whereby they can be conveniently used in dental applications. The benzoyl methyl ether is employed in these compositions as a photosensitizer. Another substance typically used in the dental restorative compositions is benzoyl peroxide, or a similar compound, which serve as a free radical initiator. 

Fong, H., 2004. Electrospun nylon 6 nanofiber reinforced BIS-GMA/TEGDMA dental restorative composite resins. Polymer (Guildford) 45, 2427-2432. 

Fig. 19.8 Results of MTT (a) and LDH (b) assays of MG-63 cells on the extracts of cured dental restorative composite resins for 7 days. Asterisk denotes a significant difference (p < 0.05) is achieved as compared to the extracts of cured nanocomposite resin containing no liquid crystalline resin (E-BP00ZL6O) (Hsu et al. 2012a)...

Sun W, Cai Q, Li P, Deng X, Wei Y, Xu M, Yang X (2010) Post-draw PAN-PMMA nanofiber reinforced and toughened bis-GMA dental restorative composite. Dent Mater 26 873-880... 

Wear of dimethacrylate resins used as the matrix phase in dental restorative composites was characterized by single-pass sliding (4). 

Processing Waxes. The extensive amount of handwork and craftsmanship necessary in the fabrication of most dental restorations and apphances has created a need for several types of wax compositions. These are known as boxing, sticky, utihty, or study waxes. 

Goldman, M. (1985). Fracture properties of composite and glass ionomer dental restorative materials. Journal of Biomedical Materials Research, 19, 771-83. 

Ansetk, K. S., Newman, S. AL and Bowman, C. N.i Polymeric Dental Composites Properties and Reaction Behavior of Multimethacrylate Dental Restorations. VoL 122, pp. 177-218. 

Dental Materials. One very practical application of photopolymer materials is in dental restoratives. Photopolymer chemistry has been adapted for use in composite fillings (67), surface coatings (68) and in the formation of impressions (69). 

Compomers are properly called polyacid-modified composite resins and are a group of aesthetic materials chemically similar to the well-established composite resins [266], They were introduced to the dental profession in the early 1990s [267], and were intended to combine the benefits of traditional composite resins and glass-ionomer cements, and their trivial name reflects this, being derived from the names of these two parent materials, the comp coming from composite, and omer from ionomer [268], These materials are now considered a distinct class of dental restorative, with well established uses in clinical restoration, particularly in children s dentistry [269],... 

Lack of adhesion of a dental restoration to tooth structure results in microleakage at tooth-restoration interface. This occurrence can result in discoloration at the margin of the restoration, or in the formation of caries. Occlusal forces on the restoration and differences between the coeffidents of thermal expansion of the cement and tooth material can lead to leakage. In addition, oral fluids and moisture may affect the adhesion. Microleakage of composite resin restorations has been reviewed by Ben-Amar [233]. Microleakage is not as serious a problem with glass-ionomer cements as it is with resin-based restorative materials, due to reduced polymerization shrinkage [234]. 

Polymeric Dental Composites Properties and Reaction Behavior of Multimethacrylate Dental Restorations... 

With over 200 million dental restorations performed each year, the importance of developing a restorative material with tooth-like appearance and properties cannot be underestimated. In this article, the use of poly (multimethacrylates) as dental composites is summarized from both fundamental and practical sides. Detail is provided regarding the utilization, procedures, and problems with polymeric composite restoratives, and a complete discussion of the polymerization kinetics and the polymer structural evolution is presented, fn the final sections, properties of current composite materials and suggestions for what areas of research would prove most promising are presented. 

With more than 200 million dental restorations performed each year, the importance of using a restorative material which is both safe and durable should not be underestimated. Currently, dental amalgam is used in the vast majority of these restorations however, recent scrutiny of mercury levels in dental amalgam and the desire for tooth colored restorations have led to increasing demand for polymeric dental composites. Polymeric composites, generally composed of a multimethacrylate and a ceramic glass filler, have primarily been used for anterior tooth restorations in which color matching is imperative for aesthetic purposes. 

Composite resins allow for color matching, conservative cavity preparation, and simple preparation through intraoral photopolymerization. These advantages have made composites an increasingly popular substitute for amalgam in dental restorations, especially when aesthetics are of concern. In this article, we will focus on the actual process of forming dental composites, the properties of the composites that are formed, and a complete description of the photopolymerization of the multimethacrylates that produce the dental composite. We will only be focusing on the use of polymers as dental restorations. Other dental applications of polymers, e.g. dentures and ionomer cements (reviewed elsewhere by Scranton and Klier) will not be addressed. 

The demand for aesthetic dental restorative materials continues to increase and may be the most important criterion for the promising future of the aesthetic polymeric composite resins. As the physical, mechanical, and wear properties of these materials improve, their use in dentistry will expand. The acid-etching of dental enamel [20] and dentin bonding procedures [21] will allow for conservative cavity preparation and the preservation of healthy tooth structure. 

Though these may provide a standard for screening production quality, they are merely representative. The flexural properties will be a consistent test of the many possible mechanical property testing modalities. Other areas of physical properties that are important to the success of a composite dental restorative are radiopacity, polymerization shrinkage and thermal interactions, e.g., thermal expansion and thermal diffusivity. 

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