Archive for the ‘ Fixed Prosthodontics ’ Category
Porcelain, resins and porcelain fused to metal are the classical and most often used materials in fixed partial prosthodontics. The teeth and presently – dental implants, used as support gives us very adequate prosthodontic rehabilitation.
All Ceramic Fixed Partial Denture with CAD CAM milled Zirconia Framework
Veneer is a thin tooth shaped glass ceramics facing luted to the underlying tooth structure using a filled resin. Veneers, also known as laminates, are usually done for esthetic purposes – to mask discoloration and to correct malformations of tooth shape, spacing and tooth chipping.
All Ceramic Veneer
Porcelain fused to metal crowns are constructed in metal alloy with porcelain fused to either all or most of its surface. PBC, also known as ceramics fused to metal dental crown is indicated in situations whrere a stronger restoration is needed, such as the presence of minimal interocclusal clearance. Compared to all ceramics dental crowns, the strength of this type of restoration is excellent.
Photo 1: Porcelain fused to metal dental crown
Cantilever Bridge, also known as Cantilever Fixed Partial Denture, is a prosthesis where the pontic (artificial tooth) is supported on one side only by one or more abutment teeth. The pontic is attached to a single or to two retainers splinted together but has no connection at the other end of the artificial tooth. The abutment tooth or teeth may be either mesial or distal to the edentulous space.
Photo 1: Cantilever Fixed Partial Denture with one abutment tooth
Fixed Moveable Fixed Partial Denture, as we define before, is a partial denture (bridge) with a rigid connector usually at the distal end of the pontic and a moveable connector that allows some vertical movement of the mesial abutment tooth. The movable connector (precision or semi-precision attachment) resists both separation of the pontic from the retainer and lateral movement of the pontic.
Segmented dental bridge has a fixed-fixed partial denture segment and a fixed movable partial denture segment.
Fixed-fixed Partial Denture, also known as fixed-fixed dental bridge, is a design of fixed partial prosthesis that has a rigid connector at both ends of the pontic. This basic design of FPD has a minimum of three units that can be cemented in one piece. The abutment teeth are rigidly splinted together and must be prepared parallel to each other. Its retainers or crowns should have approximately the same retention as each other. This is to minimized the risk that forces applied to the fixed-fixed FPD will dislodge one retainer from its abutment, leaving the FPD suspended from the other abutment.
Fixed-fixed Partial Denture for missing lateral incisor, 22 FDI Two-Digit Notation.
Fixed movable partial denture is sometimes called as fixed free partial denture. It is a partial denture where the pontic is rigidly supported on one side, usually the distal end by one or more abutment teeth. On the other side, the abutment will contain a precision abutment, a stress breaking device. This will allow a small degree or limited movement between the rigid component and the other abutment tooth or teeth. This movable joint will give full support to the pontic against vertical occlusal forces, and will allow limited movement in response to lateral forces.
The advantage of fixed movable dental bridge is that both retainers do not need to be parallel.
Tooth Preparation
Amount of Reduction in Tooth Preparation for Fixed Partial Denture
Porcelain Fused to Metal Fixed Partial Dentures like this, requires 1.2 - 1.5mm facial reduction, 0.75 - 1mm lingual reduction and 1.5 - 2mm incisal reduction.
Attachments for Removable Partial Dentures can be categorized into: intracoronal attachment or extracoronal attachment, rigid attachment or resilient attachment, and precision attachment or semi-precision attachment.
Let’s limit the discussion on the first 2 categories of attachments mentioned, the intracoronal attachment and extracoronal attachments. Intracoronal attachment for removable partial denture is either cast or attached totally within the natural contours of an abutment tooth or teeth. Typically, it is composed of prefabricated key and keyway with opposing parallel walls, which serve to limit movement and resist removal of removable partial denture through friction. The principle of internal attachment was formulated by Dr. Herman E.S. Chayes in 1906.
O-SO distal extension attachment male component on the proximal of the Fixed Partial Denture
Fixed partial dentures with cantilevers (CFPD) are among the treatment options for partial edentulism.
A cantilever beam by definition (Tylman, 1970), is a beam that is supported by only one fixed support at one of its ends. A direct cantilever bridge, is when the pontic is attached to an adjacent retainer.
The main indications for cantilever bridgework are situations in which:
1 . the teeth on either side of the proposed pontic that might ordinarily be used as abutments for fixed bridgework are unsuitable by reason of morphology, periodontal pathology or unfavorable angulation
2. cosmetic needs cannot be met by conventional fixed bridgework
3. the need to avoid unnecessary involvement of sound teeth is an overriding factor on grounds of pulpal risk, cosmetic implications or the temperament of the patient. (H. S. M. CRABB 1974)
Double Abutting Fixed Partial Denture with Cantilever