Orthodontic retainers are custom-made devices, usually made of wires or clear plastic, that hold teeth in position after surgery or any method of realigning teeth. Once a phase of orthodontic treatment has been completed to straighten teeth, there remains a lifelong risk of relapse due to a number of factors: recoil of periodontal fibres, pressure from surrounding soft tissues, the occlusion and patient’s continued growth and development. By using retainers to hold the teeth in their new position for a length of time, the surrounding periodontal fibres adapt to changes in the bone which can help minimize any changes to the final tooth position after the completion of orthodontic treatment. Retainers may also be used to treat overjets.
Dental surgery is any of a number of medical procedures that involve artificially modifying dentition; in other words, surgery of the teeth, gums and jaw bones.
A bridge is a fixed dental restoration used to replace one or more missing teeth by joining an artificial tooth definitively to adjacent teeth or dental implants.
A dental technologist is a member of the dental team who, upon prescription from a dental clinician, constructs custom-made restorative and dental appliances.
A dental implant is a prosthesis that interfaces with the bone of the jaw or skull to support a dental prosthesis such as a crown, bridge, denture, or facial prosthesis or to act as an orthodontic anchor. The basis for modern dental implants is a biologic process called osseointegration, in which materials such as titanium or zirconia form an intimate bond to bone. The implant fixture is first placed so that it is likely to osseointegrate, then a dental prosthetic is added. A variable amount of healing time is required for osseointegration before either the dental prosthetic is attached to the implant or an abutment is placed which will hold a dental prosthetic/crown.
Osseointegration is the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant. A more recent definition defines osseointegration as "functional ankylosis ", where new bone is laid down directly on the implant surface and the implant exhibits mechanical stability. Osseointegration has enhanced the science of medical bone and joint replacement techniques as well as dental implants and improving prosthetics for amputees.
In dentistry, a crown most commonly refers to a dental cap, a type of dental restoration that completely caps or encircles a tooth or dental implant. A crown may be needed when a large cavity threatens the health of a tooth. A crown is typically bonded to the tooth by dental cement. They can be made from various materials, which are usually fabricated using indirect methods. Crowns are used to improve the strength or appearance of teeth and to halt deterioration. While beneficial to dental health, the procedure and materials can be costly.
A removable partial denture (RPD) is a denture for a partially edentulous patient who desires to have replacement teeth for functional or aesthetic reasons and who cannot have a bridge any reason, such as a lack of required teeth to serve as support for a bridge or financial limitations.
A palatal lift prosthesis is a prosthesis that addresses a condition referred to as palatopharyngeal incompetence. Palatopharyngeal incompetence broadly refers to a muscular inability to sufficiently close the port between the nasopharynx and oropharynx during speech and/or swallowing. An inability to adequately close the palatopharyngeal port during speech results in hypernasalance that, depending upon its severity, can render speakers difficult to understand or unintelligible. The potential for compromised intelligibility secondary to hypernasalance is underscored when consideration is given to the fact that only three English language phonemes – /m/, /n/, and /ng/ – are pronounced with an open palatopharyngeal port. Furthermore, an impaired ability to effect a closure of the palatopharyngeal port while swallowing can result in the nasopharyngeal regurgitation of liquid or solid boluses.
Bone cements have been used very successfully to anchor artificial joints for more than half a century. Artificial joints are anchored with bone cement. The bone cement fills the free space between the prosthesis and the bone and plays the important role of an elastic zone. This is necessary because the human hip is acted on by approximately 10–12 times the body weight and therefore the bone cement must absorb the forces acting on the hips to ensure that the artificial implant remains in place over the long term.
Haramaki is a type of chest armour worn by the samurai class of feudal Japan and their retainers.
A luting agent is an application of a dental cement connecting the underlying tooth structure to a fixed prosthesis. To lute means to glue two different structures together. There are two major purposes of luting agents in dentistry – to secure a cast restoration in fixed prosthodontics, and to keep orthodontic bands and appliances in situ.
Fixed prosthodontics is the area of prosthodontics focused on permanently attached (fixed) dental prostheses. Such dental restorations, also referred to as indirect restorations, include crowns, bridges, inlays, onlays, and veneers. Prosthodontists are specialist dentists who have undertaken training recognized by academic institutions in this field. Fixed prosthodontics can be used to restore single or multiple teeth, spanning areas where teeth have been lost. In general, the main advantages of fixed prosthodontics when compared to direct restorations is the superior strength when used in large restorations, and the ability to create an aesthetic looking tooth. As with any dental restoration, principles used to determine the appropriate restoration involves consideration of the materials to be used, extent of tooth destruction, orientation and location of tooth, and condition of neighboring teeth.
A resin-retained bridge is a bridge replacing a missing tooth that relies for its retention on a composite resin cement. It is one of many available dental restoration methods which is considered minimally invasive and conservative of tooth tissue. The resin-retained-bridge has gone through a number of iterations. Perhaps the best known is the Maryland bridge and other designs used in the past include the Rochette bridge. The five-year survival rate is around 83.6% and the ten-year rate at 64.9%. The case selection is important and as with any dental prosthesis, good oral hygiene is paramount for success. In recent years, the indications for the use of resin-retained-bridges have diminished significantly and there have been changes in the principles underpinning their design. Resin-retained-bridges should be considered when a fixed prosthesis retained by natural teeth is required. The use has been driven by the advent of evidence-based dentistry showing the benefits to patients of reduced tooth preparation and the importance of an intact enamel structure for the long-term health of the teeth. The bridge is currently in favour in the United Kingdom for these reasons. Indeed, recent contemporary research shows resin retained bridges have better success rates than implants and are a cheaper alternative.
Dental cements have a wide range of dental and orthodontic applications. Common uses include temporary restoration of teeth, cavity linings to provide pulpal protection, sedation or insulation and cementing fixed prosthodontic appliances. Recent uses of dental cement also include two-photon calcium imaging of neuronal activity in brains of animal models in basic experimental neuroscience.
A dental prosthesis is an intraoral prosthesis used to restore (reconstruct) intraoral defects such as missing teeth, missing parts of teeth, and missing soft or hard structures of the jaw and palate. Prosthodontics is the dental specialty that focuses on dental prostheses. Such prostheses are used to rehabilitate mastication (chewing), improve aesthetics, and aid speech. A dental prosthesis may be held in place by connecting to teeth or dental implants, by suction, or by being held passively by surrounding muscles. Like other types of prostheses, they can either be fixed permanently or removable; fixed prosthodontics and removable dentures are made in many variations. Permanently fixed dental prostheses use dental adhesive or screws, to attach to teeth or dental implants. Removal prostheses may use friction against parallel hard surfaces and undercuts of adjacent teeth or dental implants, suction using the mucous retention, and by exploiting the surrounding muscles and anatomical contours of the jaw to passively hold in place.
After hip replacement, hip prosthesis zones are regions in the interface between prosthesis material and the surrounding bone. These are used as reference regions when describing for example complications including hip prosthesis loosening on medical imaging. Postoperative controls after hip replacement surgery is routinely done by projectional radiography in anteroposterior and lateral views.
Overdenture is any removable dental prosthesis that covers and rests on one or more remaining natural teeth, the roots of natural teeth, and/or dental implants. It is one of the most practical measures used in preventive dentistry. Overdentures can be either tooth supported or implant supported. It is found to help in the preservation of alveolar bone and delay the process of complete edentulism.
