7 rem mj RPD design and delivery.pptx

Design, Delivery and Last Thoughts CH. 20 CH. 21 CH. 23 Design Review A variety of considerations can lead to the use of a removable partial denture as the chosen prosthetic restoration in the “dental implant era.” There are unlimited Removable Partial Denture (RPD)design options. Where do you start...

Design, Delivery and Last Thoughts CH. 20 CH. 21 CH. 23 Design Review A variety of considerations can lead to the use of a removable partial denture as the chosen prosthetic restoration in the “dental implant era.” There are unlimited Removable Partial Denture (RPD)design options. Where do you start ? The steps to designing an RPD should start with and include: 1. A correct diagnosis of the remaining hard and soft tissues and 2. Careful planning for support, stability and retention (in that order ) Know Your Kennedy Classifications Design Considerations and Rules to Follow: 1. Start with the Kennedy classifications with the Applegate modifications after the hopeless teeth have been removed and any tissue modifications have been made. ( I might suggest preliminary casts for an “initial “ design if an RPD is being considered. The design can be reconsidered later if it needs to be) *** Survey the cast of the RPD arch*** 2. Remember that if a Kennedy Class I or Class II is planned that indirect retention is REQUIRED for support, stability and retention. (Kennedy Class I and II are tooth-tissue supported) * The best place for an indirect retainer is the mesial of a 1st premolar or the mesial portion of the canine to prevent upward rotational movement of the distal extension(s). * Design Considerations and Rules to Follow: 3. Tooth supported RPDs are the most successful and have the BEST long-term prognosis. Use rest seats and rests as well as clasps for direct retention. A. Occlusal rest seats should have a rounded triangular form with the apex towards the center of the occlusal surface. The Labiolingual length should be at least 2.5 mm. at the marginal ridge. The rest seat should be as long as it is wide with the mesiodistal width at least 2.5 mm. The depth must be a minimum of 1.5 mm. ( to permit for adequate metal in the framework). The deepest portion being towards the apex. So, I would prepare with 1.5 mm. at the marginal ridge with a slight angulation ( less than 90 degrees) apically to 2.0 mm. Design Considerations and Rules to Follow B. A cingulum or lingual rest is used more commonly on the maxillary arch as opposed to the mandibular ( the maxillary canine has a more prominent cingulum) The preparation should be in the form of a rounded inverted V with the mesiodistal length being 2.5 -3.0 mm. A labiolingual width of 2 mm. And a depth of 1.5 mm. The preparation can be made with an inverted cone bur and then rounded with a round bur. *Occlusal and Cingulum rest seats should be rounded and smooth. * Other Design Considerations Major Connectors: In the Mandibular arch the two most common major connectors are the Lingual Bar and the Lingual plate. *remember for a Lingual Bar major connector there must be a minimum of 7 mm. from the FGM to the floor of the mouth. * * a Lingual plate is a better choice if an anterior tooth is missing or if there are periodontal considerations for the remaining mandibular anterior teeth or if you think an anterior incisor could be lost in the life of the partial denture.* Lingual Bar Lingual Plate Other Design Considerations Major Connectors –In the maxillary arch the complete (full) palatal plate is predominantly used for a maxillary Kennedy Class I (bilateral distal extension)and Class II. For a Class III, a modified palatal plate at a palatal strap type are the most frequently used. Maxillary Palatal Plate Maxillary Palatal Strap Placement, Adjustments and Servicing a Removable Partial Denture CHAPTER 20 Framework Try-in and Wax Try-in Appointment(s) The framework should be tried in at a separate appointment to make sure of the fit to the tissue and any remaining teeth. If there are more than one or two teeth being replaced, I would also suggest a wax try-in with the acrylic denture teeth set in wax to evaluate the occlusion with the opposing arch before processing. *Make any adjustments in the framework or occlusion of the teeth in the wax prior to having the finished product processed and returned for delivery. * RPD Framework Wax Try-in Wax Try-in cont. RPD Delivery and Adjustments All to often, the removable partial denture (RPD) is placed, and the patient dismissed with only instructions to return when soreness or discomfort develops. The patient should not be given procession of the RPD before: 1. The denture bases have been adjusted. 2. occlusal discrepancies eliminated. 3. patient education continued as to maintenance and care for the RPD given. RPD Delivery and Adjustments The term adjustment has two connotations: 1. Adjustment of the denture bearing areas and the occlusal surface of the denture. 2. Accommodation by the patient to the new prosthesis. 1. Adjustment of the Denture Bearing Areas and Occlusal Surfaces of the Denture. A. Adjustment of the denture base to the supporting tissues. B. Adjustment of the occlusion of the RPD to the opposing arch. C. Final adjustments A. Adjustment of the Denture Base to the Supporting Tissues. The use of a Pressure Indicating Paste (P.I.P.) is a paste that is lightly painted in a thin film on the denture base that will have contact with the tissue surface. Lightly press the RPD to place with finger pressure on the tissue bearing areas. The RPD is then removed and inspected. Any areas that has been heavy enough to displace the thin film of indicator paste should be relieved. This process should be repeated until no areas displace the paste. *Relief is accomplished by using a slow speed handpiece, a straight nose cone and an acrylic bur.* Pressure Indicating Paste (P.I.P.) Using Pressure Indicating Paste Areas that are frequently displaced by the pressure indicating paste include: Mandibular – the lingual slope of the mandibular ridge in te premolar area, the mylohyoid ridge, the retromolar pad and the distobuccal border around the ascending ramus and the external oblique ridge. Maxillary – the inside of the buccal flange of the denture over the tuberosities, the border of the denture especially around the malar prominence, and the point of the pterygomaxillary notch where the denture might impede on the pterygomandibular raphe or the pterygoid hamulus. Occlusal Adjustments The framework of the removable partial denture should have been tried in as well as a separate wax try in, if needed, to establish the occlusal relationships of the RPD to the opposing dentition. Articulating Paper Follow-up Services The patient must understand the rationale and the need for follow-up services in the maintenance of the Removable Partial Denture. To gain maximum service from the RPD the patient must: 1. Avoid careless handling of the RPD that might lead to distortion or breakage. 2. Protect any remaining teeth from caries with proper oral hygiene, proper diet, and routine care check-ups. 3. Prevent periodontal damage to the abutment teeth and maintaining healthy tissue. 4. Accept the fact the RPD treatment can not be considered permanent and that there is responsibility for care. Relining and Rebasing a Removable Partial Denture CHAPTER 21 Definitions of Rebasing and Relining Rebase – The process of refitting a denture by replacing the entire denture base material. Reline – The process of resurfacing the tissue side of the removable prosthesis with new base material. This can be done with an in office soft reline or an office or lab hard reline. *Relining is a RPD is more common than rebasing in dental practices * *Metal framework can not be rebased or relined only the acrylic denture base* Relining A distal extension RPD which derives it’s support from the tissue of the residual ridge, requires relining much more often than a tooth supported RPD. The primary reason for relining a distal extension base is to reestablish tissue support for the base. * The patient should be advised prior to placement of the RPD that periodic examinations and relining will be required.* Reline Tooth supported Tissue changes that occur beneath a tooth supported denture base generally do not affect the support of the RPD. Reasons for Relining or Rebasing a tooth supported RPD. 1. unhygienic conditions and the trapping of debris between the denture base and the residual ridge. 2. An unsightly condition that results from the space that has developed. 3. patient discomfort associated with lack of tissue contact that arises form open spaces between the denture base and the tissue. * Rebasing is the treatment of choice if the artificial teeth are to be replaced or the denture base is defective. * Interim Removable Partial Dentures CHAPTER 23 Temporary RPD Interim Removable Partial Dentures Tooth replacement is required for a variety of reasons. The use of an interim prosthesis for a partially edentulous mouth is usually placed as a temporary restoration with the goal of minimum time and expense. An Interim prosthesis may be indicated for the following reasons: 1. Sake of appearance 2. maintenance of space 3, Reestablishment of Occlusal Relationships 4. Conditioning teeth and /or residual ridges 5. An interim restoration during treatment 6. Conditioning the patient for wearing a prosthesis 1. Appearance For the sake of appearance, an interim partial denture usually replaces one or more anterior missing teeth. It can , however, replace posterior teeth as well if required. This type of interim partial denture is fabricated with either (VLC) Visible Light Cure or a powder /liquid sprinkle type method using an autopolymerizing or heat polymerizing method. It may be retained with cast-circumferential clasps, Crozat-type clasps, interproximal metal spurs or wire loops. 2. Space Maintenance When a space results from recent extractions or trauma, it is usually prudent to maintain the space while the tissue heals or to prevent migration of the adjacent teeth. In younger patients the space may need to be maintained until the adjacent teeth mature enough to be used for fixed restoration or so that an implant can be placed. 3. Reestablishment of Occlusal Relationships Interim partial dentures can be used to: 1. To establish a new occlusal relationship or occlusal vertical dimension. 2. To condition teeth and ridge tissue for optimum support for the definitive removable partial that will follow. Interim partial dentures can be used as occlusal splints in much the same way resin or cast partials are used for natural teeth. The fixed and removable occlusal splints have a lot in common. Either of them can be eliminated in sections as the work is being completed. 4. Conditioning teeth and Residual Ridges Dr. O.C. Applegate wrote an article about the advantages of conditioning edentulous areas to provide stable support for a distal extension RPD. This is accomplished by having a patient wear an interim RPD for a period of time before the final base is fabricated. In the absence of the opposing occlusion, with only intermittent stimulation, the underlying tissue becomes more conditioned to support the distal extension denture base. Abutment teeth benefit as well by having the opportunity to become stabilized under the loading of the Interim RPD prior to the final prosthesis. 5. Interim Restoration During Treatment In some instances, an existing removable partial denture can be used with modifications as an interim partial denture. Such modifications may include relining and adding teeth and clasps to the existing partial denture. In other instances, an existing removable partial denture may be converted to a transitional complete denture for immediate placement while the tissue heals, and an opposing arch is prepared to receive a removable partial denture. Sometimes a temporary interim removable partial denture must be made to replace missing anterior teeth in a partially edentulous arch ( which are ultimately to be replaced with fixed restorations). The posterior could also be replaced with a resin rim instead of in occlusion. 6. Conditioning the patient to wear a Prosthesis A temporary prosthesis may be made to aid the patient in making the transition to complete dentures when the total loss of teeth is inevitable. This is to be considered a temporary restoration for the remaining life of the natural teeth. This type RPD may be used for longer periods as natural teeth are lost. This type interim RPD can have teeth added or rebased or relined as needed. Conditions: A dentist should ONLY agree to the type of interim RPD under the following conditions: 1. that a definite fee is for the treatment is appropriate and that the fee will depend on the services rendered. 2. that when further wearing of the transitional partial denture is unwise and jeopardizes the health of the tissue the transition to complete dentures will proceed. * The patient must always be informed of the purpose of the interim (transitional) partial denture and its limitations* Kennedy Class VI Laboratory Schedule Monday May 6th –Be sure and get your lab work authorization forms back and ask any questions about PPD designs. Make sure your surveyed Maxillary Class III Mod 1 casts have been evaluated and rubric forms turned in. Tuesday May 7th – 1 p.m. – 2:30 p.m. PRACTICAL – You will be given two cases from which to evaluate and create work authorization lab order forms on the NYU student lab authorization handouts. RED and BLUE pencil or pen REQUIRED 3 p.m. – 5 p.m. – practical make-ups and remediation. Turn in one last graded homework preparation into the box