Thermoplastic Resins used in Dentistry
Thermoplastic materials such as polyamides (nylon), acetal resins, epoxy resins, polystyrene, polycarbonate resins, polyurethane and acrylic thermoplastic resins were introduced in dentistry as an alternative to classic resins, which have major disadvantages such as the toxicity of the residual monomer, awkward wrapping system and difficult processing.
Part of the book: Thermoplastic Elastomers
Assessment of Dental Alloys by Different Methods
Alloys are used in various areas of dentistry. The field of dental alloys is a very extensive one, encompassing both the materials themselves as well as the manufacturing methods, which are constantly developing. Our chapter focuses on corrosion and biocompatibility assessment, using various methods. At present there is no perfect dental alloy. Superalloys for dental use are not yet available, and only few studies concerning the new generation of superalloy candidates for medical applications have recently been developed, with promising results.
Part of the book: Superalloys
Acrylates and Their Alternatives in Dental Applications
Acrylic resins dominated dentures technology for several decades. Due to their many disadvantages, new classes of resins, which promise better quality, constantly appear. Mechanical properties of acrylic resins, including fracture behaviour, water absorption and mechanical strength degradation caused by the exposure to saliva of classical heat-cured acrylic resins compared to alternative urethane-based light-cured resins, were carried out. The allergy potential of acrylic resins was evaluated by in vivo and in vitro tests. New choices of resins, like thermoplastic injected resins, light-cured or milled high-performance polymers, with better properties compared to acrylics, suitable for dental applications are being presented.
Part of the book: Acrylic Polymers in Healthcare
Alternative Denture Base Materials for Allergic Patients
Traditionally, a denture base is manufactured using a heat-cured acrylic resin. This type of resin was first used in dental labs in 1936, being a great step forward. Because of the many disadvantages as increased porosity, high water sorption, polymerization shrinkage, allergenic potential and citotoxicity due to the residual monomer, awkward flasking and packaging, and difficult processing, alternatives were continuously searched. Monomer-free and high-impact acrylics were developed, and gold plating of the denture base was experienced, in order to provide an alternative to allergic patients. Once polymers developed, new types of resins, such as polyamides (nylon), acetal, epoxy resins, styrene, polycarbonate, vinyl, urethane, polyether ether ketone (PEEK), became available on the dental market, accompanied by modern technologies, such as injection. CAD/CAM milled and 3D printed denture bases represent the present state of the art in this domain. Our chapter aims to present these alternative materials, which are safe to use in cases of allergic patients and guarantee a healthy oral environment and a high degree of comfort.
Part of the book: Oral Health Care
The Influence of Salivary pH on the Prevalence of Dental Caries View all chapters
Dental caries is the most prevalent chronic oral disease, influencing the oral and systemic health of the individuals, being the result of the interaction of multiple factors, such as microbial agents, the oral environment, the salivary pH, and the host response. The main process that occurs in dental caries is the demineralization of the tooth enamel, process that is directly influenced by the salivary pH, exposing the dental structures to the action of pathological agents. The role of saliva in the etiology of dental caries is a major one, by influencing the homeostasis through the altering of its buffer capacity. The properties of saliva are influenced either by local pathogens or through a general mechanism with direct implications upon the salivary components. The alteration of the salivary pH, flow rate, and composition will further have repercussions upon the cariogenic activity, through a change of its physiochemical properties. Nevertheless, the salivary pH is strongly linked to the incidence of dental caries, any persistent imbalance due to various causes can be assessed as an indicator of the oral health status.
Part of the book: Dental Caries