Types Of Bridges PDF

TYPES OF BRIDGES By : Dina Mohamed EL-Shokafy Department : Fixed Prosthodontics Is a prosthetic appliance, permanently attached to the abutment. It replaces one or more missing teeth. This type of restoration has long been called a “Bridge”.  During mastication, all chewing...

TYPES OF BRIDGES By : Dina Mohamed EL-Shokafy Department : Fixed Prosthodontics Is a prosthetic appliance, permanently attached to the abutment. It replaces one or more missing teeth. This type of restoration has long been called a “Bridge”.  During mastication, all chewing forces that act on the pontics are passed to the abutment teeth; the more artificial teeth, the greater the forces acting on the abutment teeth. Each individual pontic passes the chewing forces to abutment teeth. That is why the forces that act on the abutments are greater when the bridge has more pontics  Acrylic resin According to the material Full metallic Full ceramic Porcelain fused to metal Tooth supported Classification of fixed According to the dental prosthesis support Implant supported Implant tooth supported Minimal According to coverage amount of tooth coverage Conventional 1- Acrylic resin bridge 2- Full metallic prosthesis. 3- Full ceramic prosthesis. 4- porcelain fused to metal prosthesis. Acrylic resin bridge It is a provisional restoration Available in different shades Available in different forms Disadvantages: Low abrasion resistance wear over time High volumetric shrinkage during setting High exothermic reaction pulpal health Low color stability  Acrylic resin According to the material Full metallic Full ceramic Porcelain fused to metal Tooth supported Classification of According to the fixed dental support prosthesis Implant supported Implant tooth supported According to Minimal amount of tooth coverage coverage Conventional 1- Implant supported prosthesis: Retainers are cemented to implant abutments. 2- Tooth supported prosthesis: Natural tooth act as abutment and retainers cemented to it. 3- Implant – tooth supported prosthesis: Abutment is natural tooth from one side & the other side is implant abutment. 1- Implant supported prosthesis: Depend on the osseointegration between implant (inert material) & bone Indications: 1. single tooth 2. Distal abutment in case of free end saddle. 3. Long span edentulous area. 4. Can be used in dry mouth. 5. Instead of the tooth that need massive TTT & still weak. 1- Implant supported prosthesis: Contraindications: 1. Only if the placement of the implant will affect vital structures as maxillary sinus, inferior alveolar nerve ,…… 2. No sufficient bone dimensions 2- Implant- tooth supported bridge Connecting tooth to implant presents a biomechanical challenge. Implant is rigidly fixed to bone, but periodontal ligament allow physiologic mobility in natural tooth damaging forces on implant. Principles: 1. The natural tooth is in excellent condition with no mobility. 2. Only one pontic. 3. The use of double tooth as abutment. 4. Implant design with intra-mobile element.  Acrylic resin According to the material Full metallic Full ceramic Porcelain fused to metal Tooth supported According to Classification of fixed the support Implant dental prosthesis supported Implant tooth supported Minimal coverage According to amount of tooth coverage Conventional 1- Minimal tooth coverage A- Resin bonded bridge: The restoration consist of pontic supported by a thin metal retainers placed lingually on the abutment tooth. The reduction will be within the enamel. The attachment is made by a composite resin material, retained by the acid-etch technique to the enamel. So called resin-bonded bridges. Resin bonded bridge: Indications: 1. One missing tooth or maximum two lower incisors. 2. Ideal abutment with sufficient enamel of good quality. 3. Adequate ridge form. 4. Well aligned abutment tooth 5. Good periodontal health & no mobility 6. Cases with normal occlusion. 1- Minimal tooth coverage B- Inlay retained bridge:  Inlay-retained FDPs were introduced in 1960s & were originally made out of noble metals.  Then glass fiber-reinforced composites (FRCs) & dental ceramics were proposed Indications: low susceptibility to caries Sufficient enamel margin for adhesion when adjacent teeth have been previously restored & when implant placement is not possible  Contraindications Severe dental mal positions. Absence of enamel on the preparation margins. Extensive crown defects & mobility of abutment-teeth. 2- Conventional bridge: The retainers are cemented over the natural teeth on one or both sides of the edentulous space. The Four Basic Bridge Designs: A. Fixed-fixed bridge. B- Fixed-movable bridge. C- Cantilever bridge. D- Spring cantilever bridge A- Fixed-Fixed bridge: It is a bridge where the retainers & pontics are splinted together from both sides either by soldering or cast as one unit.. Indications: A. The first choice to replace premolar or molar after implant. B. The only choice to replace more than one missing tooth. Fixed-Fixed bridge Advantages: Disadvantages: 1. Provide maximum retention 1. Must be cemented in one & resistance. piece, so cementation is 2. The force is equally difficult. distributed between the 2. Flexing or bending may abutments. occur in long span. 3. The construction is simple because there are no 3. Preparation should be movable joints to make. parallel for proper path of insertion. 4. Can be used for long spans. B- Fixed-movable bridge: It is a bridge where the pontic is fixed by rigid connector from one side, but the other side is non rigid (rest) allowing some movement for the abutment. Indications: A. Short span to decrease the load on certain abutment. B. Difficulty of obtaining common path of insertion as in tilted tooth. C. In case of pier abutment. A- Fixed-movable bridge: (Important criteria): 1- The rest should be placed on inlay not on the tooth structure to avoid recurrent caries. 2- Occlusal or sub-occlusal rest in posterior bridge placed on class II inlay. in anterior bridge ,it is placed lingually on class III inlay. 3- The rest placed on the anterior abutment 4- Can`t be used with nonmetallic retainers. Fixed-movable bridge Advantages: Disadvantages: 1. preparations do not need to be parallel 1. Length of span limited. to each other. 2. More complicated laboratory 2. More conservative of tooth tissue. procedures. 3. Allows minor movements of teeth. 3. Difficult to make temporary 4. Parts can be cemented separately, so bridges. cementation is easy. 4. The load not equally distributed. C- Fixed-cantilever bridge: Is a fixed partial denture in which the pontic attaches to adjacent one or double retainers on one side of the bridge only. Indications: 1- Short span (only one missing tooth). 2- Mostly used in case of missed upper lateral with canine as abutment. 3- Favorable occlusion. 4- In case of pier abutment. 5- Strong abutment with good bone support. C- Fixed-cantilever bridge:. Indications: 6- for aesthetic reasons, when it is not desirable to prepare a tooth located in a visible part. 7- The missed tooth should be located anteriorly. Fixed-cantilever bridge. Advantages: Disadvantages: 1- The most conservative design as only one 1- The length of span is limited to abutment tooth is needed. one pontic. 2- Construction in the laboratory is relatively 3- Occlusal forces on pontic of straight-forward. posterior bridges encourage tilting of the abutment tooth causing tipping or tilting of the abutment or loosening of the retainer. D- Spring cantilever bridge: It is a cantilever bridge where the pontic is at the end of a resilient curved arm taking its support from an abutment remote from the edentulous space.. Indications: 1- Diastema that need to be preserved. 2- Neighboring tooth can not be used as abutment for any reason. 3- Used only in the upper arch to replace one incisor.