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Treatment planning and diagnosis /fixed orthodontics courses


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Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.

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Treatment planning and diagnosis /fixed orthodontics courses

  2. 2. FOR SINGLE TOOTH RESTORATIONS Introduction By using cast metal, ceramic and metal ceramic restorations, large areas of missing coronal tooth structure can be replaced while that which remains is preserved and protected. Function can be restored and where required, a pleasing esthetic effect can be achieved. The successful use of these restorations is based on thoughtful treatment plan. In what circumstances should cemented restorations made from cast metal or ceramic be used instead of amalgam or composite restorations?
  3. 3. The selection of material and design of the restoration is based on several factors: 1. Destruction of tooth structure 2. Esthetics 3. Plaque control 4. Financial considerations 5. Retention
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  5. 5. 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. 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. 3. Plaque control The use of cemented restorations demands the institution and maintenance of a good plaque control program to increase the chances for success of the restoration. The patient must be motivated to follow a regime of brushing, flossing and dietary regulation to control or eliminate the disease process responsible for destruction of tooth
  6. 6. 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. On one hand, you should not pre-empt the choice by selecting a less than optimum restoration just because you think that the patient cannot afford the preferred treatment. On the other hand, you also should be sensitive enough to the individual patients situation to offer a sound alternative to the preferred treatment plan and not apply pressure.
  7. 7. 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. The cemented restoration made of cast metal, metal and ceramic or ceramic material alone is fabricated away from the operatory and is luted in or on the patients tooth at a subsequent appointment. One type can be better suited for a particular application than the other or their suitabilities may overlap.
  8. 8. Restoration longevity Every dentist would like to be able to answer the patient’s question, “HOW LONG WILL MY RESTORATION LAST?”. Logical though the question may be, unfortunately it is impossible to answer directly. Clinical studies of restoration longevity have produced widely desperate figures. As a general rule, cast restorations will survive in the mouth longer than amalgam restorations, which in turn will last longer than composite resin restorations. The question of longevity is an important one to consider when deciding on treatment for a patient. The more destructive the preparation required for the restoration the greater the potential risk for the tooth, and ultimately the greater expense.
  9. 9. TREATMENT PLANNING FOR THE REPLACEMENT OF MISSING TEETH The need for replacing missing teeth for a patient is obvious to the patient when the edentulous space is in the anterior segment of the mouth. But it is equally important in posterior region. It is tempting to think of the dental arch as a static entity, but that is certainly not the case. It is in a state of dynamic equilibrium with the teeth supporting each other. When a tooth is lost, the structural integrity of the dental arch is disrupted and there is a subsequent realignment of teeth as near state of equilibrium is achieved. Teeth adjacent to or opposing the edentulous space frequently move into it.
  10. 10. Selection of the type of prosthesis Missing teeth may be replaced by one of three prosthesis types: 1. A removable partial denture 2. A tooth supported fixed partial denture 3. Implant supported fixed partial denture Several factors must be weighed when choosing the type of prosthesis to be used in any given situation. Biomechanical, periodontal, esthetic and financial factors as well as the patients wishes, are some of the more important ones. It is not uncommon to combine two types in the same arch such as a removable partial denture and a tooth supported fixed partial denture or implant supported and tooth supported fixed partial denture. In treatment planning there is one principle that should be kept in mind: treatment simplification.
  11. 11. Removable Partial Denture RPD is generally indicated for edentulous patients greater than two posterior teeth, anterior spaces greater than four incisors or spaces that include a canine and two other continuous teeth, that is central incisor, lateral incisor and canine or lateral incisor, canine and first premolar or the canine and both premolars. An edentulous space with no distal abutment will usually require a removable partial denture. The requirements of an abutment for a RPD are not as stringent as those for a fixed partial denture abutment. Tipped teeth adjoining edentulous spaces and prospective abutments with divergent alignments may lend themselves more readily to utilization as RPD rather than FPD abutments. Periodontally weakened primary abutments may serve better in retaining a well designed RPD than in bearing the load of a FPD. If there has been a severe loss of tissue in the edentulous ridge, a RPD can more easily be used to restore the space both functionally and esthetically. For successful RPD treatment the patient should demonstrate acceptable oral hygiene and show signs of being a reliable recall
  12. 12. Conventional tooth supported fixed partial denture When a missing tooth is to be replaced a fixed partial denture is preferred by a majority of the patients. The usual configuration for a FPD utilizes an abutment tooth on each end of the edentulous space to support the prosthesis. There should be no gross soft tissue defect in the edentulous ridge. If there is it may be possible to augment the ridge with grafts to enable the construction of a fixed prosthesis. Dry mouth creates a poor environment for a FPD. The margins of the retainers will be at a great risk from recurrent caries limiting the life of the prosthesis.
  13. 13. Resin bonded tooth supported fixed partial denture The resin bonded fixed partial denture is a conservative restoration that is reserved for use on defect free abutments in situations where there is a single missing tooth, usually an incisor or premolar. A single molar can be replaced by this type of prosthesis if the patients muscles of mastication are not too well developed. Thus a assuring that a minimum load will be placed on the retainers.
  14. 14. Implant supported fixed partial denture Fixed partial denture supported by implants are ideally suited for use where there are insufficient numbers of abutment teeth or inadequate strength in the abutments to support a conventional FPD, and when patient attitude and / or a combination of intraoral factors make a removable partial denture a poor choice. Implant supported FPDs can be employed in the replacement of teeth when there is o distal abutment. Span length is limited only by the availability of alveolar bone with satisfactory density and thickness in a broad flat ridge configuration that will permit implant placement.
  15. 15. No prosthetic treatment If a patient presents with a long standing edentulous space into which there has been little or no drifting or elongation of the adjacent or opposing teeth, the question of replacement should be left to the patient’s wishes. If the patient perceives no functional, occlusal or esthetic impairment, it would be a dubious service to place a prosthesis. This in no way contradicts the recommendation that a missing tooth routinely should e replaced.
  16. 16. ABUTMENT EVALUATION 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. However, the tooth must have some sound surviving coronal tooth structure to ensure longevity. The teeth that have pulp capped in the process of preparing the tooth, should not be used as a FPD abutment unless they are endodontically treated. 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.
  17. 17. The roots and their supporting tissues should be evaluated for three factors: 1. Crown root ratio 2. Root configuration 3. Periodontal ligament area
  18. 18. Crown root ratio This ratio is a measure of the length of the 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 the chance for harmful lateral forces is increased. The optimum crown root ratio for a tooth to be utilized as a FPD abutment is 2:3. A ratio 1:1 is the minimum ratio that is acceptable for a prospective abutment under normal circumstances. Root configuration This is an important point in the assessment of an abutment’s suitability from a periodontal standpoint. Roots that are broader labio-lingually than they are mesio-distally are preferable to roots that are round in cross section. Multi-rooted posterior teeth with widely separated roots will offer better periodontal support than roots that converge, fuse or generally present a conical
  19. 19. Periodontal ligament area Another consideration in the evaluation of prospective abutment teeth is the root surface area or the area of periodontal ligament attachment of the root to the bone. Larger teeth have a greater surface area and are better able to bear added stress. FPDs with thick short pontic spans have a better prognosis than do those with excessively long spans. In a statement designated as by Johnson et al the root surface area of the abutment teeth had to equal or surpass that of the teeth being replaced with pontics.
  20. 20. SPECIAL PROBLEMS Pier abutments An edentulous space can occur on both sides creating a lone free standing pier abutment. Physiologic tooth movement, arch positions 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.
  21. 21. Tilted molars 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 FPD along the long axis of the respective teeth and achieve a common path of insertion. A proximal half crown sometimes can be used as a retainer on the distal abutment. This preparation design is simply a three quarter crown that has bee rotated 90 degrees so that the distal surface is uncovered. If there is a severe marginal ridge height discrepancy between the distal of the second molar and the mesial of the third molar as a result of tipping, the proximal half crown is contraindicated. A telescope crown and coping can also be used as a retainer on distal abutment. A non rigid connector is another solution to the problem of the tilted FPD abutment.
  22. 22. Canine replacement FPD FPDs replacing canines can be difficult because the canine often lies outside the inter abutment 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 FPD replacing a maxillary canine is subjected to more stresses than that replacing a mandibular canine since the forces are transmitted outwards (Labially) on the maxillary arch against the inside of the curve (weakest point). An edentulous space created by the loss of a canine and any two contiguous teeth is best restored with a RPD.
  23. 23. Cantilever FPD A cantilever FPD is one that has an abutment or abutments at one end only with the other end of the pontic remaining unattached. This is a potentially destructive design with the lever arm created by the pontic, and is frequently misused. 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. A cantilever can also be used to replace a missing first premolar. This scheme will work best if occlusal contact is limited to the distal fossa.
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