Lec.1 C & B (1).pdf

Lec.1 Dr. Ali Crown and Bridges Prosthesis: is the replacement of an absent part of human body by an artificial part. Dental prosthesis: is the device or restoration which replaces one or more lost teeth, portion of the crown or the entire...

Lec.1 Dr. Ali Crown and Bridges Prosthesis: is the replacement of an absent part of human body by an artificial part. Dental prosthesis: is the device or restoration which replaces one or more lost teeth, portion of the crown or the entire crown. Prosthodontics is one of the branches of dentistry that deals with the replacement of missing teeth and the associated soft and hard tissues by prostheses (crowns, bridges, dentures) which may be fixed or removable, or may be supported and retained by implants. The types of dental prosthesis are: 1. Removable dental prosthesis: this type of prosthesis that inserted and removed by the patient. It could be: a. Partial denture: which is supported partially by edentulous ridge and other part by remaining natural teeth. b. Complete denture: Which supported completely by edentulous ridge. 2.Fixed dental prosthesis: Is the restoration which is fixed firmly in place and cannot removed by the patient and gains its support only from remaining natural teeth. Crown and bridges It is a branch of dental sciences that deals with restoring damaged teeth with artificial crowns & replacing missing natural teeth by a cast prosthesis that is permanently cemented in place. Crown: It's an artificial fixed restoration of the coronal Part of a natural tooth. It must restore contour, function of the tooth, morphology and should protect the remaining tooth structures from further damage. Bridge: It's a fixed prosthesis fabricated to replace the one or more missing teeth. Abutment: It is the natural tooth that supports the bridge and on which retainer is cemented. Retainer: is that part of the bridge which is cemented to the abutment tooth and it could be any type of crown or inlay. Pontic: is that part of F.P.D. which replaces the missing tooth and restore the function and aesthetic of missing tooth. Connector: is that part of F.P.D. which connects a pontic to a retainer or two retainers to each other. Connectors could be either fixed or allow some movements between the components that they join. Pier abutment: is an abutment tooth standing between and supporting two pontics, each pontic being attached to a further abutment tooth. Span: is the space between natural teeth that is to be filled by the bridge. Unit: A unit when applied to bridge work means either a retainer or a pontic. A bridge with two retainers and one pontic would therefore be a three unit bridge. Inlays: are intracoronal restorations which are manufactured in the laboratory and cemented in place into the prepared cavity in the tooth. It is used to restore individual tooth contour and function. Inlays involve the occlusal, proximal surface or surfaces. It could be either: gold inlays, composite inlays and porcelain inlays. Onlays: are extracoronal restorations on the occlusal surface of the tooth. The Class II onlay involves the proximal surface or surfaces of the posterior teeth and covers the cusps. What's the difference between inlay, onlay, and crown? Inlay: (intracoronal restoration gain its retention from the internal surface of the prepared cavity in the tooth. Crown is extracoronal restoration gains its retention from the outer surface. Onlay is extracoronal restoration. The occlusal outline and proximal boxes of an onlay preparation are similar to those of an inlay. The additional steps are the occlusal reduction and a functional (centric) cusp ledge. The MO inlay preparation The MOD onlay preparation on mandibular first premolar on mandibular first molar Purposes Of crown Construction; 1. To restore the fractured tooth, grossly damaged tooth or the tooth with a large filling (amalgam or composite). 2. To restore the speech and function of mastication. 3. To restore the esthetic and Improve the appearance of patients. 4. Recontouring the occlusion to maintain the periodontal health by and prevents food impaction. 5. As a retainer for the bridge. Materials used in the crown and Bridge The materials used in the construction of crown and Bridge could be either: A. Metal (Gold alloy and it's alternatives) as in Full metal Crown and 3/4 Crown. B. Plastic materials: Such as Acrylic resin as in jacket crown. C. Ceramic and Zircon material. D. A combination: of metal and plastic materials as in full veneer Crown. Bridge composed of gold, ceramic and combination. parts of fixed dental prosthesis (Bridge)