Academic literature on the topic 'Methacrylate embedding'

Modern restorative materials can be classified in several ways, in terms of their retention (chemically adhesive, macro-, micro- or even nanomechanical), their chemistry (e.g. resin-based vs. acid–base reaction, filler particles), or their clinical properties (e.g. aesthetics, strength, handling). It is essential that these materials are considered closely with the histological substrate to which they will adhere or with which they will interact, in order to understand the complexities of each system and their potential clinical uses. This chapter will outline and discuss aspects of dental materials science to enable the reader to understand and appreciate the links with relevant histology and relate this to the clinical aspects of minimally invasive operative dentistry. Also discussed is dental amalgam, still a popular restorative material among many dentists worldwide, although clinical indications for its use are becoming more limited as treatment rationales change and adhesive materials improve. This text will require supplementation from suitable dental histology and detailed dental material science texts. Dental resin composites are aesthetic, plastic adhesive restorative materials that consist of co-polymerized methacrylate-based resin chains embedding inert filler particles (conferring strength and wear resistance) and requiring a separate adhesive (bonding agent) to micro-/ nano-mechanically bond them to either enamel or dentine, respectively. However, not all modern dental composites are based purely on this methacrylate resin chemistry (see Section 7.2.6). Therefore the term ‘composite resin’ is inappropriate and should not be used. Resin composites have developed over the past 50 years, after the introduction of the acid-etch technique (Buonocore, 1955) and methacrylate monomers (Bowen’s resin—Bis-GMA (1971); see Section 7.2.2). The unset (or uncured) material consists of a mixture of several different types of resin methacrylate monomers, most of which are hydrophobic (water-hating) in nature (see Figure 7.1). The monomer chain length affects certain properties of the resin composite:… • Viscosity (or flowability) of the material. This is important in order to minimize voids trapped within the uncured composite during placement and packing within the depths of a cavity (the stiffer the consistency, the greater the risk of trapping air voids). The shorter the uncured monomer length (and therefore the lower the molecular weight), the lower is its viscosity. Often shorter-length, lower-molecular- weight methacrylate monomers form the basis of the resin chemistry of flowable resin composites, and other diluent molecules may be added.

Native tissues are composed of functional three-dimensional (3D) units on the scale of 100–1000μm. The 3D architecture of these repeating units underlies the coordination of multicellular processes such as proliferation, differentiation, migration and apoptosis[1]. The requirement for 3D biomimetic matrices to mimic in vitro the ECM microarchitecture found in vivo becomes relevant in complex and vascularized tissue engineered models[2]. Among others, photopolymerizable hydrogels offer tunable geometrical features similar to the macromolecular-based components of soft ECM [3], can be crosslinke