Week 2 Lect 2 Treatment Planning in Fixed Prosthodontics PDF

 Diagnosis & treatment planning in FPD Definition It is a logical sequence of treatment in steps designed to restore the patient’s dentition to good health with optimal function & appearance Diagnosis is simply defined as the procedure of collecting data and informations through differen...

 Diagnosis & treatment planning in FPD Definition It is a logical sequence of treatment in steps designed to restore the patient’s dentition to good health with optimal function & appearance Diagnosis is simply defined as the procedure of collecting data and informations through different channels so that a proper line of treatment could be proposed.  Elements of proper diagnosis I - History (medical and dental) II- T M J, Occlusal evaluation and muscles of mastication III- Intra-oral examination IV- Diagnostic cast analysis V- Full mouth radiographic evaluation  All the data and information obtained through various diagnostic channel are collect, extensively studies and analyzed in order to develop a precise treatment plan  The proposed plan should be prepared in written form, and discussed in details with the patient before any irreversible procedures are to be undertaken  Treatment sequence:- The logical sequence of treatment steps should be decided, it includes:- Phase I: Symptomatic treatment for acute and chronic symptoms. Phase II: Stabilization phase includes: Improving of oral hygiene and elimination of caries. Phase III: Preparatory phase includes: Orthodontic, surgical, endodontic and periodontal treatments. Phase IV: Definitive phase includes: Occlusal adjustment, and teeth restoration. Phase V: Follow up phase Phase I : Symptomatic treatment : Includes: Treatment of emergencies to relief discomfort associated with acute conditions as, fractured tooth or teeth, acute pulpitis,  acute exacerbation of chronic pulpitis, dental abscess, acute pericronitis or gingivitis and any facial pain Treatment of non acute problems as example, the patient may has a specific problem that should receive immediate treatment as, lost anterior crown,  a cracked or broken porcelain veneer or fractured removable prosthesis.  Treatment sequence:- The logical sequence of treatment steps should be decided, it includes:- Phase I: Symptomatic treatment for acute and chronic symptoms. Phase II: Stabilization phase includes: Improving of oral hygiene and elimination of caries. Phase III: Preparatory phase includes: Orthodontic, surgical, endodontic and periodontal treatments. Phase IV: Definitive phase includes: Occlusal adjustment, and teeth restoration. Phase V: Follow up phase Phase II Stabilization phase : Involves stabilization of conditions, it includes: 1- Plaque control and improving the oral hygiene by good oral hygiene instructions. Phase II Stabilization phase : 2-Diet control (in patient with rampant caries( Phase II Stabilization phase : 3- Removal of calculus and debriding the root surface by a curette gingiva must be treated first to control bleeding, to local the finish line easy and to get accurate impression. Phase II Stabilization phase : 4- Corrections of defective or over hanging restorations, open inter proximal contacts and recontouring of over contoured crowns especially at the furcation area. Phase II Stabilization phase : 5- Excavations of caries and placement of temporary restoration in order to decide after that what type of restoration to be used. Phase II Stabilization phase 6- Occlusal therapy in case of malocclusion. Phase II Stabilization phase : 7- Minor orthodontic movement to create sufficient space for the tooth to be replaced Phase II Stabilization phase : 8- Provisional splinting, if we have mobile teeth, referred to periodontal treatment, so until then they must be fixed together (splinted) by provisional restoration  Treatment sequence:- The logical sequence of treatment steps should be decided, it includes:- Phase I: Symptomatic treatment for acute and chronic symptoms. Phase II: Stabilization phase includes: Improving of oral hygiene and elimination of caries. Phase III: Preparatory phase includes: Orthodontic, surgical, endodontic and periodontal treatments. Phase IV: Definitive phase includes: Occlusal adjustment, and teeth restoration. Phase V: Follow up phase Phase III: Preparatory phase includes: 1-Oral surgery 2-Periodontal surgery 3-Endodontic treatment 4-Orthodontic treatment Phase III: Preparatory phase includes: 1-Oral surgery  Extraction of hopeless teeth grade 3 mobility severe bone loss resistant abscess Phase III: Preparatory phase includes: 2- Periodontal surgery. Crown lengthening  Phase III: Preparatory phase includes: 3-Endodontic treatment Phase III: Preparatory phase includes: 4-Orthodontic treatment  Treatment sequence:- The logical sequence of treatment steps should be decided, it includes:- Phase I: Symptomatic treatment for acute and chronic symptoms. Phase II: Stabilization phase includes: Improving of oral hygiene and elimination of caries. Phase III: Preparatory phase includes: Orthodontic, surgical, endodontic and periodontal treatments. Phase IV: Definitive phase includes: Occlusal adjustment, and teeth restoration. Phase V: Follow up phase Phase IV Definitive treatment: A- Treatment planning for single tooth B- Treatment planning for missing tooth A- Treatment planning for single tooth : Factors affecting selection of the material and design of restoration are: 1- Destruction of tooth structure 2- Esthetics 3- Plaque control 4- Financial consideration 5- Retention A- Treatment planning for single tooth : 1-Destruction of tooth structure If the amount of destruction previously suffered by the tooth to be restored is such that the remaining tooth structure must gain strength and protection from the restoration cast metal or ceramic is indicated over amalgam or composite resin A-Treatment planning for single tooth :- Factors affecting selection of the material and design of restoration are: 1-Destruction of tooth structure 2-Esthetics 3-Plaque control 4-Financial consideration 5-Retention A-Treatment planning for single tooth :- 2-Esthetics If the tooth to be restored with a cemented restoration is in a highly visible area, or if the patient is highly critical, the cosmetic effect of the restoration must be considered. Sometimes a partial veneer restoration will serve this function. Where full veneer coverage is required in such an area, the use of ceramic in some form is indicated. Metal-ceramic crowns can be used for single-unit anterior or posterior crowns, as well as for fixed partial dentures.  Metal ceramic restoration All-ceramic crowns are most commonly used on incisors, although they can be used on posterior teeth when an adequate bulk of tooth structure has been removed A-Treatment planning for single tooth :- Factors affecting selection of the material and design of restoration are: 1-Destruction of tooth structure 2-Esthetics 3-Plaque control 4-Financial consideration 5-Retention A-Treatment planning for single tooth :- 3-Plaque control: The use of a cemented restoration demands the institution and maintenance of a good plaque- control program to increase the chances for success of the restoration A-Treatment planning for single tooth :- Factors affecting selection of the material and design of restoration are: 1-Destruction of tooth structure 2-Esthetics 3-Plaque control 4-Financial consideration 5-Retention A- Treatment planning for single tooth :- 4-Financial considerations: Finances are a factor in all treatment plans, because someone must pay for the treatment. If the patient is to pay, give your best advice and then allow the patient to make the choice. A- Treatment planning for single tooth : A- Treatment planning for single tooth :- Factors affecting selection of the material and design of restoration are: 1-Destruction of tooth structure 2-Esthetics 3-Plaque control 4-Financial consideration 5-Retention A- Treatment planning for single tooth :- 5-Retention Full veneer crowns are unquestionably the most retentive. However, maximum retention is not nearly as important for single- tooth restorations as it is for fixed partial denture retainers. It does become a special concern for short teeth and removable partial denture abutments. B- Treatment planning for missing tooth Why missing teeth should be replaced? Effect of loss of teeth When a tooth is lost, the structural integrity of the dental arch is disrupted, and there is a subsequent realignment of teeth as a new state of equilibrium is achieved.. Teeth adjacent to or opposing the edentulous space frequently move into it. Adjacent teeth, especially those distal to the space, may drift bodily, although a tilting movement is a far more common occurrence If an opposing tooth intrudes severely into the edentulous space, it is not enough just to replace the missing tooth To restore the mouth to complete function, free of interferences, it is often necessary to restore the tooth opposing the edentulous space In severe cases, this may necessitate the devitalization of the supererupted opposing tooth to permit enough shortening to correct the plane of occlusion  Replacement of missed teeth may be accomplished by one of three prosthesis types A-Removable partial denture B- Tooth-supported fixed partial denture: 1- Conventional type 2- Resin bonded bridge C-Implant-supported fixed partial denture A-Removable partial denture B -Tooth-supported fixed partial denture 1- conventional type 2-Resin bonded bridge C-Implant-supported fixed partial denture Factors affecting the selection of prosthesis type 1. The biomechanical considerations 2. The prospective abutment 3. Esthetic requirements 4. Patients `s desire 5. Financial factors 6. Clinicians ` skills 7. Laboratory support 8. Patients motivation and expected cooperation 1-Biomechanical considerations A -span length. B -double abutment. C -Arch curvature. Biomechanical considerations:- ) A) Span length: All FPDs long or short, flex because of the forces being applied through the pontic to the abutments. In addition to the increased load placed on the periodontal ligament , longer spans are less rigid Bending or deflection varies directly with the cube of the bridge length and inversely with the cube of the occluso- gingival thickness of the pontic. Bending or deflection varies directly with the cube of the bridge length (2)³=8 times 3)³=27 times  If there is a one unit of deflection for a span length (x), deflection will be 8 times as greater if the length is doubled (2x³) and 27 times as great if the span is tripled (3x³(  On the other hand a pontic with a given occluso-gingival dimension will bend a certain amount. If its thickness is decreased by one half will bend 8 times as much Clinical sequelae of bridge flexing Fracture of porcelain veneer Connector breakage Retainer lossening An unfavorable soft tissue responce 1-Biomechanical considerations A -Span length. B- Double abutment. C- Arch curvature. B -double abutment. Double abutments are sometimes used as a means of overcoming problems created by unfavorable crown-root ratios and long spans A secondary abutment must have at least as much root surface area and as favorable a crown-root ratio as the primary a canine can be used as a secondary abutment to a first premolar primary abutment but it would be unwise to use a lateral incisor as a secondary abutment to a canine primary abutment 1-Biomechanical considerations A -span length. B -double abutment. C -Arch curvature. C -Arch curvature. Arch curvature has its effect on the stresses occurring in a fixed partial denture. When pontics lie outside the interabutment axis line, the pontics act as a lever arm, which can produce a torquing movement. This is a common problem in replacing all four maxillary incisors with a fixed partial denture, This can best be accomplished by gaining additional retention in the opposite direction from the lever arm and at a distance from the interabutment axis equal to the length of the lever arm Factors affecting the selection of prosthesis type 1. The biomechanical considerations 2. The prospective abutment 3. Esthetic requirements 4. Patients `s desire 5. Financial factors 6. Clinicians ` skills 7. Laboratory support 8. Patients motivation and expected cooperation 2-The prospective abutment Every restoration must be able to withstand the constant occlusal forces to which it is subjected. This is of particular significance when designing and fabricating a fixed partial denture, since the forces that would normally be absorbed by the missing tooth are transmitted, through the pontic, connectors, and retainers, to the abutment teeth. Evaluation of the abutment A- Vital sound teeth Whenever possible, an abutment should be a vital tooth. However, a tooth that has been endodontically treated and is asymptomatic, with radiographic evidence of a good seal and complete obturation of the canal, can be used as an abutment Teeth that have been pulp capped in the process of preparing the tooth should not be used as FPD abutments unless they are endodontically treated. B- Supporting tissues The supporting tissues surrounding the abutment teeth must be healthy and free from inflammation before any prosthesis can be contemplated. Normally, abutment teeth should not exhibit mobility, since they will be carrying an extra load. The roots and their supporting tissues should be evaluated for three factors: 1-Crown-root ratio 2-Root configuration 3-PDL area 1-Crown-root ratio This ratio is a measure of the length of tooth occlusal to the alveolar crest of bone compared with the length of root embedded in the bone As the level of the alveolar bone moves apically, the lever arm of that portion out of bone increases, and the chance for harmful lateral forces is increased  The optimum crown-root ratio for a tooth to be utilized as a fixed partial denture abutment is 2:3 A ratio of 1 1 is the minimum ratio that is acceptable for a prospective abutment under normal circumstances If the occlusion opposing a proposed fixed partial denture is composed of artificial teeth, occlusal force will be diminished, with less stress on the abutment teeth. The roots and their supporting tissues should be evaluated for three factors: 1-Crown-root ratio 2-Root configuration 3-PDL area 2- Root configuration Roots that are broader bucco-lingually than mesio-distally are better than rounded ones Multirooted teeth are better than single root Divergent roots better than fused ones Curved roots are better than straight ones The roots and their supporting tissues should be evaluated for three factors: 1-Crown-root ratio 2-Root configuration 3-PDL area  3-PDL area Teeth with the larger root surface area are more capable to withstand higher stresses Ante’s law: The root surface area of abutments had to be equal or exceed that of teeth being replaced with pontics When replacing one missed tooth , FPD will be very successful  When replacing 2 teeth ,FPD will be challengeable while replacing 3 teeth , FPD will be at high risk to fail Short pontic spans are more successful than long ones It is possible for fixed partial dentures to replace more than two teeth, the most common examples being anterior fixed partial dentures replacing the four incisors.  Special problems 1- Pier abutment 2- Tilted molar 4 3- Canine- replacement 4- Cantilever F P D 1- Pier abutment An edentulous space can occur on both sides of a tooth, creating a lone, freestanding pier abutment Physiologic tooth movement, arch position of the abutments, and a disparity in the retentive capacity of the retainers can make a rigid five-unit fixed partial denture a less than ideal plan of treatment A nonrigid connector on the middle abutment isolates force to that segment of the fixed partial denture to which it applied. The location of the stress-breaking device in the five unit pier-abutment restoration is placed on the middle abutment, The keyway of the connector should be placed within the normal distal contours of the pier abutment, and the key should be placed on the mesial side of the distal pontic. The female (keyway) portion of non-rigid (stress- breaking) connector put in the distal surface of pier abutment intra-coronally 2- Tilted molar A common problem that occurs with some frequency is the mandibular second molar abutment that has tilted mesially into the space formerly occupied by the first molar It is impossible to prepare the abutment teeth for a fixed partial denture along the long axes of the respective teeth and achieve a common path of insertion There is further complication if the third molar is present. It will usually have drifted and tilted with the second molar. The fixed partial denture will not seated because the tooth distal to it intrudes on the path of insertion To solve the problem 1-The treatment of choice is the up-righting of the molar by orthodontic treatment. In addition to placing the abutment tooth in a better position for preparation and for distribution of forces under occlusal loading, In addition to placing the abutment tooth in a better position for preparation and for distribution of forces under occlusal loading, The third molar, is often removed to facilitate the distal movement of the second molar 2- If orthodontic correction is not possible A proximal half crown sometimes can be used as a retainer on the distal abutment 3- A telescope crown and coping can also be used as a retainer on the distal abutment. A full crown preparation with heavy reduction is made to follow the long axis of the tilted molar. An inner coping is made to fit the tooth preparation, and the proximal half crown that will serve as the retainer for the fixed partial denture is fitted over the coping 4-The nonrigid connector is another solution to the problem of the tilted fixed partial denture abutment A full crown preparation is done on the molar, with its path of insertion parallel with the long axis of that tilted tooth. A box form is placed in the distal surface of the premolar to accommodate a keyway in the distal of the premolar crown 3-Canine- replacement F P D Fixed partial dentures replacing canines can be difficult because the canine often lies outside the interabutment axis. The prospective abutments are the lateral incisor, usually the weakest tooth in the entire arch, and the first premolar, the weakest posterior tooth. A fixed partial denture replacing a maxillary canine is subjected to more stresses than that replacing a mandibular canine, since forces are transmitted outward (labially) on the maxillary arch, against the inside of the curve (its weakest point( On the mandibular canine the forces are directed inward (lingually), against the outside of the curve (its strongest point) Any fixed partial denture replacing a canine should be considered a complex fixed partial denture. No fixed partial denture replacing a canine should replace more than one additional tooth. An edentulous space created by the loss of a canine and any two contiguous teeth is best restored with a removable partial denture. 4-Cantilever F P D A cantilever fixed partial denture is one that has an abutment or abutments at one end only, with the other end of the pontic remaining unattached. When a cantilever pontic is employed to replace a missing tooth, forces applied to the pontic have an entirely different effect on the abutment tooth. The pontic acts as a lever that tends to be depressed under forces with a strong occlusal vector A cantilever can be used for replacing a maxillary lateral Incisor. There should be no occlusal contact on the pontic in either centric or lateral excursions The canine must be used as an abutment, and it can serve in the role of solo abutment only if it has a long root and good bone support.