Removable Prosthodontics PDF 2019

School of Dentistry REMOVABLE PROSTHODONTICS A CLINICAL GUIDE TO THE PROVISION OF COMPLETE AND REMOVABLE PARTIAL DENTURES PW Smith, AJ Preston 2019 The provision of satisfactory complete dentures and removable partial dentures (RPDs) sho...

School of Dentistry REMOVABLE PROSTHODONTICS A CLINICAL GUIDE TO THE PROVISION OF COMPLETE AND REMOVABLE PARTIAL DENTURES PW Smith, AJ Preston 2019 The provision of satisfactory complete dentures and removable partial dentures (RPDs) should be a team approach involving the clinician, the technician, and the patient. All should be involved in the design and construction of dentures in their respective ways. The clinician must be aware of the patient’s requirements and take ultimate responsibility for the final prosthesis. The technician should be involved with the practicalities of the design and must follow the prescription exactly. It can be beneficial, where feasible, to involve the technician in the surgery where he/she can see the patient and understand any problems faced by the clinician. The patient must be aware and accept the limitations of dentures and be prepared to make efforts to habituate to denture wearing. This guidance document is informed principally by the current standard guidelines, available from The British Society of Prosthodontics (BSSPD.org), for the construction of complete and partial dentures. Provision of Complete Dentures Complete dentures are constructed to restore normal speech, provide occlusal and facial support and adequate masticatory function. They should have a pleasing appearance, be comfortable to wear, and not prejudice the health of the supporting tissues. There can, however, be no guarantee that they will satisfy all these criteria for patients who have poor denture bearing areas, poor denture control skills, poor motivation, or an intolerance to prostheses. Preparation of the mouth prior to treatment and the design of complete dentures is the responsibility of the clinician. Uppermost in the clinician’s mind should be the need to aid habituation of the patient to denture wearing. Examination, Diagnosis and Treatment Planning In order to formulate the treatment plan, a medical and dental history should be taken and a clinical examination carried out, together with any appropriate investigations. Edentulous patients can be particularly self-conscious about their appearance without dentures, and the surgery environment should be conducive to their privacy. A denture-wearing history should be taken, with key information elicited about the length of time that the patient has been edentulous; about the number of sets of dentures worn, if any; and about the age of any dentures currently being worn. Such questions can provide useful information about the patient’s ability to habituate to dentures. A thorough examination of the denture bearing areas is essential. On occasion, assigning the edentulous ridges to a numerical classification can be helpful in aiding communication between clinicians. However, of greater importance, is that the clinician assesses the nature and quality of the ridges, especially in terms of alveolar undercut, ridge height and width, and sulcus depth. Such observations should be noted mentally and recorded in the case notes. Only in this way can the clinician assess the currently-worn dentures in relation to the patient’s complaints, and estimate the prognosis for provision of any new dentures. Any existing dentures should be carefully assessed, both outside and inside the mouth, in terms of extension, retention, stability, position of the teeth and aesthetics. Since many denture problems are associated with an incorrect occlusal vertical dimension (OVD), it is absolutely paramount that an estimation of the freeway space (FWS) be made at this point. Radiographs should only be taken when there are clear clinical indications, such as the suspected presence of retained roots. There must follow a detailed diagnosis, such as, for example, poorly extended peripheries; poorly designed dentures; or inadequate FWS. There should be a clear, detailed treatment plan, listing all the steps to be taken to ensure more successful dentures this time. The parameters to be incorporated in the new dentures should be recorded, and might include, for example, increasing/decreasing the FWS (and if so, by how much); correctly extending the dentures; and ensuring that the artificial teeth are placed over the ridges, especially in the lower arch. Any pathological conditions should be investigated and appropriate treatment provided in order to render the oral tissues healthy before final impressions are made. Denture-related stomatitis (DRS) is inflammation of the mucosa underlying a removable prosthesis or appliance and has been reported to affect between 15-75% of denture wearers. This definition can be interpreted widely but excludes lesions with known aetiologies, such as allergies to denture materials. DRS is usually asymptomatic and typically affects the hard palate. Angular cheilitis may occur concurrently. Candida albicans is the commonly associated pathogen. Aetiological factors in DRS may be divided into those related to the prosthesis and those that may be a manifestation of predisposing systemic conditions.. Factors related to the prosthesis include; trauma caused by an ill-fitting and unstable denture, reduced vertical dimension, the age of the dental prosthesis and its continuous wearing and a lack of oral and prosthesis hygiene. The infective causes are mainly associated with Candida albicans which proliferates between the supporting mucosa and the fitting surface of the denture. Treatment of DRS should be directed towards the cause with appropriate adjustments to dentures and advice to patients on not wearing dentures continuously along with information about denture and oral hygiene. Should there be a significant infective component the prescription of appropriate antifungal therapy might be appropriate. DRS that fails to resolve following this strategy should be referred for an Oral Medicine opinion as there might be an underlying predisposing systemic condition that requires further investigation. Any elective oral surgery procedures, for e.g. extraction of roots, management of cysts, should be carried out at an early stage. Finally, the expected outcome should be put to the patient, ideally in writing. First Impressions The requirements of the first or primary impressions are that they should accurately record clinically relevant features of the edentulous mouth without excessive tissue distortion. They should be made in rigid stock trays, which are of the metal, autoclavable type or the rigid, thick plastic, disposable type with an integral (non- detachable) handle. Trays can be modified as necessary, to fit the form of the denture bearing area and to fully extend the impression. The materials suitable for extending or modifying stock trays are modelling wax or silicone putty. The standard material for maxillary edentulous impressions is alginate, with silicone putty as an alternative. Silicone putty is helpful when the ridges are severely resorbed or if the impression tray is a poor match for the arch form. The standard material for mandibular edentulous impressions is silicone putty, with alginate as an alternative when the residual alveolar ridge is well formed. Where the resultant impression is overextended in relation to the functional depth of the sulcus, a clear indication of the sulcus extent should be marked on the impression in either pen or indelible pencil, to help the technician in the construction of special trays. Special Trays The decision as to which impression material is to be used for second impressions must be made prior to prescribing the special trays. The optimum choice of impression materials is discussed in the next section. The special trays to be prescribed are visible light cured (VLC) acrylic spaced trays, the design of which is dictated by the arch, and by the chosen impression material, as follows: For alginate, the upper special tray should be 2 - 3mm spaced with a cranked handle and three ‘tissue stops’ incorporated in the fitting surface. When synthetic elastomer is to be used, a spacing of 1.5 - 2mm should be prescribed, with the same design. The lower special tray for alginate should have 2 - 3mm spacing with a vertical stub handle and two finger-rests in the premolar region. For synthetic elastomer (Poly Vinyl Siloxane), a spacing of 1.5 - 2mm should be prescribed, with the same design. Ideally, the lower tray peripheries should also be slightly under-extended by 1mm. Second Impressions These should record the entire functional denture bearing area to ensure maximum support, retention, and stability for the eventual denture during use. Each special tray should be examined in the mouth and modified as necessary, in accordance with this requirement. Areas of tray overextension should be reduced by grinding using an acrylic trimmer in a straight handpiece. Areas of significant under-extension can be modified by the addition of a suitable material such as softened ‘greenstick’ or iso- functional wax (‘pinkstick’) to the tray and then moulding this in the patient’s mouth. The maxillary impression, in order to ensure adequate lip and cheek support, should show an intact rounded record of the labial and buccal sulci, together with the fraena. It should extend posteriorly to the hamular notches and just beyond the junction of the hard and soft palates. The mandibular impression should show an intact rounded record of the labial, buccal and lingual sulci, including the fraena. It should extend posteriorly to cover the retromolar pads. The standard material for maxillary second impressions is alginate. Occasionally, the upper ridge may be so poor that alginate becomes difficult to use. In this situation, a two-stage approach can be taken using synthetic elastomer - a basic impression is taken in heavy-bodied silicone (in the clinic this can be found in a bench top mixing machine [‘Pentamix machine’]), followed by a medium or light- bodied silicone wash. The standard material for mandibular second impressions, in the case of a well- formed edentulous ridge, is alginate. As an alternative, when the lower ridge is resorbed, as is often the case, a two-stage technique is employed, using synthetic elastomer. Again, this involves the use of a heavy-bodied (NOT putty) silicone together with a medium or light bodied PVS wash to refine the impression when indicated. Jaw Registration Registration blocks are prescribed to standard sizes and the bases which carry the occlusal rims should be rigid and stable. Additional rigidity can be conferred on the lower block by means of a ‘wire strengthener’ or VLC acrylic base. At the outset of this stage, consideration must be given to the OVD or occlusal face height (OFH), together with the amount of freeway space to be provided. These values should have been determined at the treatment planning stage. At the registration stage, therefore, the clinician needs only to confirm what the OVD is to be, with the aim of incorporating this in to the completed prescription. In other words, the exact OVD must be established at the start, and borne in mind throughout the appointment, as the clinician works towards this figure on completion of the jaw registration. The OVD should provide for most patients a minimum inter-occlusal clearance (freeway space) of 2-4 mm in the premolar region. However it is necessary to take into account the amount of freeway space the patient has become accustomed to with previous dentures and this might necessitate providing a more generous freeway space. The establishment of an appropriate occlusal vertical dimension is absolutely paramount at this clinical stage. It is established by adjustment of the lower occlusal rim and verified using various techniques of clinical measurement. If in doubt, it would be better to err on the side of providing more freeway space, rather than less, since the consequences of an inadequate FWS can be severe. Failure to provide sufficient freeway space may lead to acute muscular discomfort, temporomandibular joint pain, extreme pain involving the denture bearing areas, and possible increased alveolar bone resorption. In addition, there may be poor appearance, particularly in relation to an inability to bring the lips together; speech difficulties; and difficulty with eating and mastication. Excessive freeway space, or an inadequate OVD, is likely to produce a very poor appearance, often with a collapsed face and folding at the corners of the mouth. Such angular folds encourage the pooling of saliva at the corners of the mouth, and predispose the patient to a chronic and often painful condition known as angular cheilitis. Again, there may well be masticatory difficulties but, in this instance, this will be more to do with ineffective chewing rather than discomfort. Other problems may include discomfort from the temporomandibular joints, speech difficulties and cheek biting. Once the clinician has an OVD value to work towards, jaw registration should proceed in a systematic, step-by-step fashion, starting with the upper wax rim. Lip support: The upper rim is modified labially by adding or removing wax to give correct lip support, which will vary from patient to patient. Aesthetics are uppermost here and, although attempts have been made to confer scientific measurements on the position of the labial profile, it is the clinician’s sense of what is acceptable in terms of appearance coupled with the patient’s view which is important. Accordingly, this is the most subjective step of all. Previously successful dentures will be of considerable help with this step, as will the patient’s wishes. When the clinician is satisfied with the lip support created, it is prudent to gain the patients approval, using a face mirror, before proceeding to the next step. The height of the upper block is now established. The upper block is trimmed, preferably on a heated registration block trimmer, to indicate the position of the occlusal plane. This indicates to the technician the level of the incisal edges of the upper anterior denture teeth, particularly in relation to the position of the resting lip. The position of the occlusal plane will vary considerably from patient to patient, and there are no hard and fast rules about where to place it. Factors to be taken into consideration are the age of the patient (younger patients tending to show more tooth below the resting upper lip than older patients); the length of the upper lip (the longer the lip, the more that the anterior teeth should be covered; and how much tooth the patient is already used to showing, if any. In the absence of any helpful information, especially where complete dentures have previously not been worn, and if the lip length allows, the plane could be placed 1-2mm below the level of the resting lip. Care should be exercised though, since, in the natural dentition, there is a tendency to show less upper teeth during aging, and more of the lower teeth. An excessive amount of upper teeth showing will nearly always look artificial. Next, the horizontal plane, or more correctly, the horizontal component of the occlusal plane is created. Imaginary lines relating to the midpoint of the pupils are sometimes useful here, but it must be borne in mind that facial asymmetry is common, and so the inter-pupillary line is not always helpful. Instead, in this situation, the registration rim is trimmed to be at right angles to the patient’s sagittal plane, which, with some practice, is relatively easily done. The final parameter to be included in the prescription for the upper denture is the antero-posterior plane, or the antero-posterior component of the occlusal plane. Again, standard text book advice in determining this plane is to imagine lines on the outside of the skull, and some clinicians may find this a good starting point. It should be borne in mind that the intention behind establishing this plane is to provide stable dentures. For maximum stability of the dentures during function, the occlusal plane should be parallel to the underlying alveolar ridge. An alternative technique, therefore, would be to use the upper registration rim which should be trimmed to be reasonably parallel to the underlying ridge. At this point, the upper registration block is essentially complete and should not require further adjustment unless a final review of the blocks suggests otherwise. With regard to the lower registration rim, a number of parameters need to be incorporated simultaneously. Even occlusal contact must be achieved at the correct occlusal vertical dimension and in the correct horizontal jaw relationship. This means that the lower registration rim must be trimmed so that it meets the upper block at the established occlusal vertical dimension. At the same time, the blocks must meet evenly with the jaws in the retruded contact position (RCP). RCP is a reproducible position at which the denture teeth are placed in the intercuspal position (ICP). Once this position can be reproduced, the bucco-lingual width of the lower occlusal rim should be adjusted to identify the “denture space” (neutral zone). More often than not, this will mean that the teeth on the finished dentures will be in a crossbite. This is important in order to provide tongue space, facial soft tissue support, and denture stability. In particular, for maximum stability, the lower anterior rim should be centred over the alveolar ridge. (In some situations, when the upper ridge is favourable, the maxillary teeth can be set further buccally, within acceptable limits of cheek support, and this can offset the tendency to a crossbite.) A centre line should be marked on the upper and lower rims. This will usually be coincident with the midline of the face. It may also be advantageous to mark the upper and lower rims with check lines in the premolar regions. Locating the rims together: The occlusal rims must then be located securely together in the mouth in RCP. Small V-shaped notches are cut bilaterally in the occlusal surface of the upper rim prior to the use of a suitable registration material. Wax as a recording medium in these circumstances is not recommended. Semi- flexible silicone registration materials have the advantage of allowing relocation if the rims become detached during transportation. The procedure to be followed is to apply suitable adhesive (universal adhesive for use with polyvinylsiloxane/silicone) to the occlusal surface of the lower wax rim. The bite registration material silicone is applied over this and both rims are placed in the patient’s mouth and located together in RCP. The prescription accompanying the registration should give details of the shade, mould, and manufacturer’s brand of the teeth chosen. Details of the selected teeth to be used should also be recorded in the case notes. Any special requirements in the arrangement of the artificial teeth, such as a median diastema, should be indicated on the laboratory card. A diagram may also help the technician with the tooth arrangement. Where a particular form of anterior tooth arrangement with an existing dentures is to be repeated, an alginate impression of this denture, that can be cast in dental stone will be helpful to guide the technician. Trial insertion or “Try-in” The purpose of this clinical stage is to ensure that all the parameters which were included in the complete denture prescription, at the registration stage, have been included in the trial dentures. Again, a systematic approach to checking all the features of the prescription should be taken. Tooth position and arrangement should provide adequate lip and cheek support and tongue space, and give a pleasing appearance to the patient. The position of the occlusal plane, and the occlusal vertical dimension should both be verified as correct. Even occlusal contact and the correct horizontal relationship in RCP should be confirmed. The requirement for clear speech should be assessed. When the clinician is satisfied that all aspects of the prescription have been included, that the OVD is correct, and that the patient’s appearance is acceptable, the patient should be given the opportunity to see the trial dentures in place. It would be prudent to obtain their agreement verbally (and ideally in writing) that the appearance is satisfactory. Finally, the position of the posterior palatal border of the maxillary base or post dam should be determined. This should be positioned slightly anterior to the junction of the hard and soft palates, lying on displaceable but non-moving tissue. It is the clinician’s responsibility to mark the post dam on the master cast in the appropriate position, using a pencil. Not all trial dentures will be perfect and some will have minor faults, whereas in others there will be major faults. Minor alterations should be carried out at the chairside by the clinician, who should be prepared to remove and re-set teeth in order to achieve an appearance which is mutually acceptable. Where major alterations are required to the OVD, the occlusal plane, the vertical or horizontal jaw relationships, a new registration (re-registration) will be required and a re-try necessary. Commonly occurring major faults in the vertical occlusion would include a substantial premature contact, anterior open bite, or posterior open bite; and an inadequate or excessive OVD. Other major faults at the Try-in stage requiring a second Try-in, but not necessarily needing a re-registration, would include issues with the centre line; the shade or mould of the chosen teeth; prominence of the anterior teeth; excessive overjet; and the position of the lower teeth in relation to the underlying ridge. Insertion of the dentures or “Finish” At the Finish appointment, the denture bases should be inspected and any remaining sharp edges, surface blemishes or defects removed. Each denture should be inserted and assessed for extension, retention, stability, and appearance. Factors assessed at the trial denture stage such as lip support, vertical and horizontal jaw relationships, and speech should be reconfirmed as correct. It is particularly important that the OVD is checked and confirmed as correct. Articulating paper must be used at this stage, to examine the occlusion and articulation in the mouth. Processing inaccuracies will almost certainly have been introduced into the occlusion through small movements of the teeth in the flask. Where these have not previously been adjusted by means of a check record in the laboratory, the dentures must be “ground in” at the chairside. This is done, firstly, using only vertical movements to identify any high spots in the occlusion. When the clinician is satisfied that there is an even distribution of ink marks on all the cusps of all the posterior teeth, articulation can then be assessed. Any high spots appearing on non-supporting cusps, that is, buccal upper or lower lingual cusps, are again reduced until even contact is achieved in lateral movements. In all cases where the peripheries of the finished dentures have been reduced; where the polished surfaces have been altered; or where the occlusal surfaces of the teeth have been ground, the roughened acrylic must be re-polished and returned to its original smooth state. The clinician must, therefore, assume responsibility for polishing the dentures again, in order to avoid irritation to the oral mucosa and tongue, and the potential for staining of the roughened surface. Finally, when the clinician is satisfied that all has been done that can be done, the patient should be given the opportunity to both see the dentures in place and to comment on their comfort at this stage. The patient must be alerted to the likelihood of initial discomfort and habituation difficulties, and given careful instructions regarding the use and home care of their dentures. These warnings and instructions should be given verbally and reinforced in written form by means of an instruction leaflet. It essential that the patient be reviewed at a follow-up appointment arranged, ideally, not more than one week later. First Inspection or Review At the review appointment, a note should be made of the patient’s experiences or complaints. With these in mind, the denture bearing areas should be examined for signs of denture trauma, as evidenced by inflammation or ulceration. The tissues should be examined, even in the absence of patient complaints, since many patients may be unaware of pressure areas, possibly due to a relatively high threshold of pain. Adjustments to the peripheries or fitting surface of the dentures should be made in the light of the visual examination and the patient’s complaints. In cases where the patient has not been able to wear the dentures, sore areas may have healed to the point of not providing any evidence of trauma. In such cases, pressure indicating paste or other suitable material may be used on the fitting surface of the dentures to indicate areas of excessive tissue displacement or pressure. Adjustments should continue until the patient reports an improvement. The occlusion and articulation should be assessed again at this stage, and adjusted and refined if necessary. The nature and extent of the adjustments made should be recorded in the casenotes to make follow-up easier. Depending on the patient’s experiences and the amount of adjustment required, one or more further inspection appointments may be necessary. The patient should continue to be seen until they can manage with their dentures perfectly satisfactorily. When the time comes to discharge the patient at the end of treatment, the importance of attending for regular review in the future should be impressed upon the patient. Reline Procedures for Complete Dentures Denture relining involves the resurfacing of the impression surface of the denture to improve the fit of the prosthesis. This can be done with a temporary chairside relining material or as a definitive indirect laboratory procedure. Chairside lining materials are available that either remain soft (so called soft linings or tissue conditioners) or set hard. One examples of a chairside soft lining material available is Coe-Soft, and an example of a tissue conditioner is Visco-gel. Both materials are presented as a powder and liquid and are mixed to a viscous consistency and applied to the fitting surface of the denture to be relined. The denture is then seated in the mouth. Using either the opposing natural teeth or the opposing denture the patient is instructed to bite gently together (this is important as it prevents significant changes to the occlusion that might otherwise occur). When the material has set sufficiently the relined denture is removed and inspected to make sure that the reline is free from defects and deficiencies. These materials are intended to provide temporary improvement in fit over what can be a variable period lasting from a few days to several weeks and depends on the amount of use, dietary factors and home care. Patients should be instructed to avoid using chemical cleansers and to rinse carefully and gently brush to clean the denture. Laboratory reline procedures can use materials that are designed to remain soft for extended periods or also hard acrylic depending on the requirements of the clinical situation. All laboratory relines require a chairside wash impression to be made in the denture that is being relined. The impression material of choice is PVS light or medium bodied depending on the extent of the reline and the appropriate adhesive should be applied to the denture fitting surface. The chosen impression material should be added to the fitting surface of the denture being relined with care taken not to overload the denture, and again it is essential that the impression is made with the denture in occlusion. It should be noted that alginate is NOT a suitable impression material to be used in wash reline impressions as it is insufficiently accurate in thin section and is liable to tear. The denture with the impression is decontaminated and sent to the laboratory where a stone model is cast and the reline material can be added and processed. An example of a definitive soft lining material is Molloplast-B, a silicone based material. Definitive hard reline materials are usually either self- curing acrylic resin or heat cured acrylic resin. Copy Technique The above guidelines are intended to cover conventional techniques used in the different stages of complete denture construction. However, a denture duplication or copy technique can be valuable for some patients, particularly the elderly who might have difficulty habituating to new dentures because of changes to polished surface contour compared with previously well-tolerated dentures. The key aspect of the copy technique is that it allows the shape of the polished surfaces to be replicated thereby facilitating the patient’s neuromuscular adaptation. In cases where previous dentures have been worn satisfactorily, this technique can enable reasonably similar copies to be made with a minimum of clinical visits. Although the clinical aspects might be simplified the same is not true of the technical requirements, and these are often more challenging, time consuming and costly compared with conventional replacement dentures. It is important to understand that denture duplication is not a panacea technique for replacing dentures, and the potential for things to go awry between the clinic and the laboratory is fairly high. Nevertheless, with careful treatment planning, some cases can usefully be selected for making replacement dentures using this technique. A useful way in which to consider when a copy complete denture might be deemed an appropriate treatment modality for a particular patient is to think of the patient’s existing set of dentures as having three surfaces: the impression or fitting surface, the occlusal surface and the polished surface. If it has been diagnosed that the problem with the patient’s existing set of dentures is with either the fitting surface (for instance, when the basic fit of the denture has been lost over time through alveolar bone resorption) or with the occlusal surface (for instance, when the occlusal surfaces of the denture teeth have become worn over many years), then it is possible that the copy denture might be an appropriate form of treatment. If, however, the problem with the existing dentures has been diagnosed as an inappropriate polished surface (for instance, when the basic tooth position or neutral zone management is incorrect), then the copy denture will NOT be an appropriate form of treatment, as the copy denture technique cannot meaningfully address discrepancies of an existing complete denture’s polished surface. Indications There are several indications which would suggest the use of a copy technique. These would include cases where the existing dentures have been worn for a considerable number of years and the patient has been very happy with them. The dentures may now seem to the patient to be getting rather loose. Duplicating the dentures should aid habituation, since the shape and size of the dentures remains the same, especially the contours of the polished surfaces, and the pattern of occlusion also remains the same. The case for using the technique would be even greater if the patient also was of an advanced age. When the patient wishes to have new dentures made very quickly, a copy technique might be useful because of the fewer clinical visits involved. Other indications would include situations where relatively new dentures have been bleached by inappropriate use of cleansers or where the denture base material is unacceptable for other reasons, such as processing faults. Apart from, perhaps now, a poor fitting surface, the more faults that have to be corrected in the dentures, the less it becomes a copy technique. It is possible to correct small problems in the occlusion due to wear, and to correct an excessive freeway space, but this will usually require an additional registration appointment, at which carefully controlled changes can be made. This, of course, increases the number of clinical stages and rather undermines the advantage of having fewer clinical visits. Contraindications Complete dentures that have been diagnosed as having inappropriate tooth position, neutral zone management or polished surface contour should not be duplicated. Significantly under-extended or over-extended dentures should not be duplicated (small degrees of denture periphery under-extension or over-extension can be accommodated with the copy denture technique). It is unlikely that dentures with poor aesthetics will be suitable for duplication, especially if the position of the anterior teeth is unacceptable or the amount of lip support is inadequate or excessive. The technique is unsuitable for partial dentures and some immediate complete dentures (flangeless design). Clinical Stages First clinical stage: The usual sequence of copy technique clinical stages would begin with the taking of impressions of all surfaces of the existing dentures, using alginate in copy boxes. At the same visit, the occlusion of the dentures should be checked outside the mouth. In most cases, the occlusion should be self-evident, but where the teeth are worn, some form of occlusal record will be required. This can often be done simply with a bite wafer in the form of a small sheet of modelling wax, softened over a Bunsen flame, and placed between the upper and lower denture teeth in the mouth. The patient is guided to close together into ICP, thus registering the occlusal relationship. Care should be taken to ensure that the wax wafer has been thinned to the point of perforation by the teeth - otherwise the registration will be incorrect. The shade of the denture teeth should be selected at this stage. In some cases when a greater change in occlusion is required a separate registration stage will be needed, the denture(s) being copied are used to form replica record rims. Laboratory prescription: this depends on the next clinical stage. If the occlusal changes are minimal the next clinical stage will be a try-in and you will need to request the laboratory to pour the copy moulds with the tooth spaces poured in modelling wax with self-cure acrylic bases. The resulting duplicates are then articulated (A-V articulator) and anterior and posterior teeth are set for a wax trial. You need to specify the shade of the teeth but the mould of teeth should be evident to the technician from the copy mould. If the next clinical stage requires a separate registration and you are using the copies as ‘replica registration rims’ then you will request the laboratory to pour the copy moulds with modelling wax in the tooth spaces and self-cure acrylic bases. The teeth are not set for a wax trial. Second Clinical stage: If trial dentures have been provided by the laboratory they are essentially replicas of the original dentures polished surfaces in wax with new denture teeth. The trial denture stage is carried out in the same way as for conventional complete dentures. When both clinician and patient are satisfied with the occlusion and with the appearance of the trial dentures, second (‘wash’) impressions are made of the denture bearing areas. This is done by means of a “closed mouth”, wash technique. With one trial denture already in place, suitable adhesive and a medium-bodied silicone impression material is applied to the fitting surface of the other trial denture. This is then placed in the mouth and the patient is asked to close together while the material sets. In this way, providing that the patient has closed into the correct occlusal relationship, the OVD and the pattern of occlusion are kept the same as the original dentures. Once this impression has been checked, it is returned to the mouth and the procedure is repeated for the opposing denture. Once both impressions have been completed they are decontaminated and are then ready to send to the laboratory. (‘Wash’ impressions are done only after any periphery modifications that have been deemed necessary are completed and significant baseplate undercuts, if present, have been removed with an acrylic bur.) If an additional registration stage is required the laboratory will have returned replicas of the patient’s dentures that have modelling wax teeth and self-cure acrylic bases. These are treated as you would registration rims that have already been adjusted for lip support. Modelling wax is usually added to the occlusal surface of the lower wax rim to the desired OVD and the jaw relationships are recorded. The completed registration is decontaminated and ready to send to the laboratory. Laboratory prescription: In the case of wash impressions in wax trial dentures the prescription to the laboratory will be to cast the impressions and finish the dentures. If a registration has been carried out the prescription will be for the laboratory to articulate the registration in an A-V articulator and to set anterior and posterior teeth for wax trial. Make sure that you have selected the shade of the teeth and, if required, the mould, although the necessary mould can be matched to the copy denture teeth in the dental laboratory from their stock of artificial teeth. Third clinical stage: this will depend on the previous clinical stage and will be either to fit the finished dentures or wax trial dentures. Fitting the dentures proceeds in the same way as for conventional dentures. The wax trial appointment procedures are carried out in the same way as those described above for copy dentures and require a wash impression. Laboratory prescription: if wax trial has been done see above. Subsequent Clinical stages are the same as for conventional dentures. These will be either fit or review depending on what was carried out in the preceding clinical stage. Provision of Partial Dentures In essence, removable partial dentures (RPDs) are intended to restore either function or appearance, or both. Therefore, partial dentures should assist the mastication of food, be cosmetically pleasing and help maintain normal speech. They may also be required to maintain oral health and to prevent tilting, drifting and overeruption of natural teeth. They may not always be necessary, and should never be made merely to fulfil a philosophy of replacing every single missing tooth. Partial dentures should be designed and constructed in such a way as to avoid compromising the health of the oral tissues. A high standard of oral hygiene is usually necessary on the part of the patient, and there is an expectation that the clinician will make every effort to assist the patient in achieving an acceptable level of plaque control. Preparation of the mouth prior to prosthodontic treatment and the design of RPDs is the responsibility of the clinician. Regardless of whatever type of partial denture is to be made, the underlying principles of support, retention and stability should be understood and incorporated into the denture design. There is an almost infinite degree of variation between partial denture cases and, so, it is difficult to lay down any sort of uniform approach to every clinical situation. Each individual case, therefore, needs thoughtful care. As each case is approached differently, the clinician must take responsibility for providing a clear prescription to the laboratory at each clinical stage. Examination, Diagnosis and Treatment Planning In order to formulate the treatment plan, a medical and dental history should be taken, noting the patient’s complaints, dental experience and attitude to treatment. A clinical examination should be carried out, together with any appropriate investigations. The natural teeth should be examined, and their number, position and occlusal relations noted. The presence of any caries, unsound restorations, plaque, periodontal disease and tooth mobility should be recorded. Evidence of bruxism and non-carious tooth substance loss should be noted. The condition of the oral mucosa, denture bearing areas and, in particular, the amount of height and undercut remaining in the ridges of the edentulous areas should be examined. Any existing dentures should be inspected in relation to the natural teeth and edentulous saddles, bearing in mind any comments made by the patient during the history taking. Radiographs of the teeth and supporting tissues may be necessary. Pathological conditions should be investigated and treated appropriately. Even at this early stage, it is essential that a decision is made regarding the type of dentures to be provided in terms of denture base material. It is not enough to simply prescribe “partial dentures” - the choice between acrylic or cobalt-chromium must be made early. The clinician must think ahead, drafting the provisional design of the dentures, so that the most appropriate restorations are placed in any natural teeth that will act as RPD abutments. When crowns or cast restorations are to be used to restore abutment teeth, they should be designed to incorporate suitable features for the partial denture such as rest seats, guide planes, milled ledges and adequate undercuts for clasps. Preparation of the Mouth The mouth should be prepared and returned to a state of health before prosthodontic treatment. Dietary analysis and advice; oral hygiene instructions and attention to plaque control should be given as appropriate. The extraction of teeth and the removal of any retained roots should be carried out as early as possible, in order to allow healing to take place, together with early alveolar resorption and remodelling. All forms of periodontal treatment and restorative treatment should be completed prior to partial denture construction. Impressions for Study Casts In the assessment of partially dentate patients, study casts are as essential as the clinical examination, in the planning of partial dentures. For these first, partially dentate impressions, a metal or rigid disposable polycarbonate tray should be selected and modified where necessary. Depending on the number and arrangement of standing teeth, and the extent of resorption of the residual ridges, a two-stage technique may be required. Silicone putty is placed within the tray where there are extensive edentulous saddles in the mandibular or maxillary arch, or in the palatal aspect of the upper tray where there is a high vault to the palate. The purpose of the putty is to support the alginate that has to go beyond the edges of the impression tray and ensure that the primary impression is correctly extended, this cannot be done with alginate alone. It is especially important that the putty is pushed into the disto- lingual sulci and around the tuberosities in order to ensure that the alginate used in the second stage of the impression is properly supported and extended, and that bony undercuts may be utilised. In the second stage of the impression, alginate is used to record the teeth, palate, edentulous areas and labial, buccal and lingual sulci. It is worth noting that, here, the alginate will form a thin wash where it covers the earlier putty. In cases where there are only small edentulous saddles, or single tooth spaces, the use of alginate alone should suffice and additions of silicone putty described above are not needed for an adequate primary impression. Casts should be poured in stone and, where the occlusion is self-evident, mounted on an articulator in the intercuspal position (ICP). In some instances, it is possible to hand-hold the casts for analysis of the occlusion. Where the occlusion is not self- evident, and where a cobalt-chrome RPD is planned, occlusal rims should be constructed and either ICP or the retruded contact position (RCP) recorded, depending on the natural teeth present and position required. Later, the mounted casts should be examined and the occlusion compared with that of the patient, and, unless alteration to the occlusal relationship is being made deliberately, they should be the same. This means that in all cases where a cobalt-chrome RPD is planned, except those where the opposing arch is edentulous, models should be surveyed and presented on an articulator ready for the design stage. Primary Jaw Registration In many cases, a jaw registration stage may be required at the patient’s second appointment. The deciding factors are the occlusion, or lack thereof, and the type of dentures to be made. A primary jaw registration is required when a cobalt- chrome RPD is to be provided and its design is likely to be influenced by occlusal relationships. A primary registration is NOT required when a complete denture will oppose the partial denture or where acrylic dentures only are being provided. Where the occlusion is not self-evident, wax occlusal rims should be constructed and the occlusion registered. When only one RPD is planned, it may still be necessary, in some cases, to employ both upper and lower partial registration blocks. Subsequently, there will often be situations where no further occlusal record is required, but there will be some cases where, for greater accuracy, the jaw registration should be recorded again using occlusal rims constructed on a duplicate master cast and mounted on the cast metal framework. Where a later definitive registration is not anticipated, a shade should be taken at this stage, using the remaining natural teeth as a guide. Partial denture design The design of a partial denture is the duty and responsibility of the clinician. It is essential that both written and diagrammatic instructions are submitted to the laboratory on the prescription card. Restorative work involving technical procedures requires a close working relationship between clinician and technician, and discussion of a proposed design, firstly, with the technician and, subsequently, with the patient, enhances the likely success of the treatment. The cast should be surveyed, choosing the most appropriate path of insertion for the denture in relation to suitable guide planes, tooth and bony undercuts, and appearance. Acrylic RPD design is generally much more straightforward than for cobalt-chromium based dentures, but the principles remain the same. The type of clasp and material to be used should be included in the prescription. In the case of metal-based dentures, the framework should be designed outlining the saddle areas, occlusal and other support, the direct retainers and any necessary indirect retention to prevent rotation. Resistance to lateral and antero-posterior displacing forces should be planned, and connectors should be rigid and strong with minimal gingival coverage. Any tooth modification procedures necessary to improve the effectiveness of the design should be identified. In addition to the creation of rest seats and guide planes; the recontouring of buccal or lingual tooth surfaces; and occlusal adjustments, it is sometimes useful to modify the natural teeth by the addition of adhesive restorative materials to create usable tooth undercut, e.g. the use of composite bonded to etched enamel. Naturally occurring guide surfaces should be identified and used where possible, as this minimises the need for tooth preparation in the creation of parallel guide surfaces. The design and written instructions should form a comprehensive prescription for the laboratory to follow, aided, sometimes, by a design drawn on the study cast. Tooth Preparation During the design process, the need for various types of tooth modification will have been identified, particularly in the case of cobalt-chromium based dentures. This tooth preparation must be carried out before the working impressions are taken, usually at the same visit. In the case of occlusal rests, these will typically be prepared 0.5 mm to 1 mm into enamel, but, when all tooth preparation procedures have been carried out, it should be confirmed that there is sufficient clearance for the denture base and components. Second Impressions These should be recorded using a 3 mm spaced, acrylic special tray. The standard material for both maxillary and mandibular second impressions is alginate. In some cases, to prevent tearing and distortion of the impression material, large interdental spaces beneath contact points should be blocked out in the mouth using soft ribbon wax, before making the impression. Alginate impressions should be cast immediately after disinfection, to minimise dimensional change. The accuracy of impressions to be used for the construction of a cast metal framework is paramount, and the need to minimise distortion cannot be overemphasised. Each impression should be examined for defects and the surface should exhibit clear detail. No part should be detached from the tray. Any excess unsupported bulk of material should be removed with a sharp blade to prevent distortion when the impression is put down on the work surface. Subsequently, in the laboratory, master casts should be treated with great care to avoid the risk of abrasion, and duplicate master casts should be made for use at a later stage. Try-in of the cast metal framework In the case of Co-Cr dentures, following construction of the metal casting, this should be presented to the clinic on the master cast. The completed framework should conform precisely to the design prescription sent to the laboratory by the clinician. The framework should be tried in the mouth, where it is assessed. The first step is to ensure that the metal casting seats fully, and that all component parts are correctly located. In particular, it should be ensured that occlusal rests fully engage their prepared rest seats. Failure to seat perfectly or minor errors causing pressure or discomfort may be located using a disclosing material and corrections made to ensure a precise fit. The use of “Occlude” powder spray is particularly useful here, but pressure indicating cream should not be used. The fitting surface of the casting is eased until it seats fully home. In the Dental School you are encouraged to discuss the adjustments with your tutor and if required the dental technician who made the casting. Occasionally, even after a number of adjustments, a casting may still not fit and, in extreme cases, it may appear that the framework is completely distorted in comparison with the patient’s mouth. Since the casting will always fit the master cast, if it does not fit the mouth, then the most likely source of error is the impression. Unless the master model has been damaged, abraded or inaccurately ‘blocked out’, it is likely that it is inaccurate because the impression from which it was made has distorted. The clinician’s only option then is to take a new impression and to ask for a new casting to be made. Once the clinician is satisfied that the framework fits accurately, with no sharp edges, and has ensured that the clasp arms do not impinge on the mucosa and terminate in the correct depth of undercut, it can then be assessed for retention and stability. Occlusal relationships should be examined with the framework in the mouth and any interferences or premature contacts with the opposing teeth identified. These high spots can then be reduced. Only minor interferences can be dealt with by altering the framework, since excessive thinning increases the risk of subsequent fracture. There should be a minimum thickness of 1mm at the junction of an occlusal rest with its minor connector. It should be said that although the adjustment of opposing teeth as part of the treatment plan, to provide a satisfactory denture, is acceptable, modification at the Try-in of Casting stage, because of lack of room, demonstrates poor clinical practice. At the conclusion of this stage, providing that the framework fits well and that it does not interfere with the occlusion, the clinician may request that a wax occlusal rim be added to the metalwork in order to subsequently record the definitive jaw relationship. Definitive Jaw Registration This stage may not be necessary only in those cases where the primary jaw registration is transferable to the master casts. In the case of chrome dentures, the occlusion will often have been recorded previously. However, for greater accuracy, the jaw registration should be recorded again using occlusal rims constructed on a duplicate master cast and mounted on the cast metal framework. Because of the great variation between partial denture cases, it is not possible to lay down ‘hard and fast’ rules for every situation, beyond a few general principles. At the outset of the registration stage, consideration must be given to the OVD. Where there are natural teeth in occlusion, they will usually provide an appropriate OVD as long as they are in contact. Where there are no natural teeth in occlusion, and where there are no existing dentures to serve as a guide, the clinician must establish what the OVD is to be, with the aim of incorporating this into the completed prescription. Where there are both upper and lower registration blocks, the upper block is trimmed first, to indicate the position of the occlusal plane. Even occlusal contact is established between upper and lower teeth/occlusal rims. It will later be necessary for the technician to be able to locate the upper and lower models in a stable and unambiguous way, so the clinician should take one of two approaches to secure the recording, using either wax or bite registration material. In the first method, occlusal rims opposing natural teeth can be left slightly “high”. Then the surface wax is softened with a heated blade and the patient is asked to close, so that occlusal contact is achieved at the correct face height. Alternatively, the wax rims can be trimmed slightly out of occlusion, adhesive is applied to one rim, and flexible silicone bite registration material is added to that rim. The patient is asked to close together and to remain closed while the material sets, thus registering the occlusal relationship. Either method, carried out carefully, is acceptable, and should produce an accurate result. Where the RPD is to be opposed by a complete denture, a jaw registration will always be necessary. Finally, if there was not an earlier, primary jaw registration, the shade (and mould, if necessary) of the denture teeth should be selected at this stage. Again, the remaining natural teeth should be used to aid shade selection. Trial insertion or “Try-in” The purpose of this clinical stage is to ensure that all the parameters which were included in the partial denture prescription, at the registration stage, have been included in the trial dentures. Where both upper and lower RPDs are being provided, the upper trial denture is checked first, and then the lower, separately. Then, both trial dentures can be checked together. Tooth position and arrangement should conform to the contours and occlusion of the remaining natural teeth, in accordance with the prescription. Where anterior teeth are being replaced, the position of the occlusal plane and the replacement teeth should give a pleasing appearance to the patient. Where necessary, the occlusal vertical dimension should be verified as correct. Even occlusal contact and the correct horizontal relationship should be confirmed. The requirement for clear speech should be assessed. When the clinician is satisfied that all aspects of the prescription have been included, that the OVD is correct, and that the patient’s appearance is acceptable, the patient should be given the opportunity to see the trial dentures in place. It would be prudent to obtain their agreement verbally (and ideally in writing) that the appearance is satisfactory. Finally, in the case of upper bilateral free-end saddles, the position of the posterior palatal border of the maxillary base or post dam should be determined. This should be positioned slightly anterior to the junction of the hard and soft palates, lying on displaceable but non-moving tissue. It is the clinician’s responsibility to mark the post dam on the master cast in the appropriate position, using a pencil. Not all trial dentures will be perfect and some will have minor faults, whereas in others there will be major faults. Minor alterations should be carried out at the chairside by the clinician, who should be prepared to remove and re-set teeth in order to achieve an appearance which is mutually acceptable. As with complete dentures, where major alterations are required to the OVD, the occlusal plane, the vertical or horizontal jaw relationships, a new registration (re-registration) will be required and a re-try necessary. Insertion of the dentures or “Finish” Finished partial dentures, which have been processed on the blocked-out master cast, should, ideally, be presented to the clinician on the duplicate master cast. At the Finish appointment, the denture base should be inspected and any remaining sharp edges, surface blemishes or defects removed. Dentures should be inserted and assessed for extension, retention, stability, and appearance. Factors assessed at the trial denture stage such as tooth position, vertical and horizontal jaw relationships, and speech should be reconfirmed as correct. Where necessary, it is important that the OVD is checked and confirmed as correct. Horseshoe articulating paper must be used at this stage, to examine the occlusion and articulation in the mouth. Processing inaccuracies will almost certainly have been introduced into the occlusion through small movements of the teeth in the flask. Where these have not previously been adjusted by means of a check record in the laboratory, the dentures must be “ground in” at the chairside. This is done, firstly, using only vertical movements to identify any high spots in the occlusion. When the clinician is satisfied that there are no occlusal interferences, articulation can then be assessed. Any high spots appearing are again reduced until even contact is achieved in lateral movements. Only minimal adjustment should be required. In all cases where the peripheries of the finished dentures have been reduced; where the polished surfaces have been altered; or where the occlusal surfaces of the teeth have been ground, the roughened acrylic must be re-polished and returned to its original smooth state. The clinician must, therefore, assume responsibility for polishing the dentures again, in order to avoid irritation to the oral mucosa and tongue, and the potential for staining of the roughened surface. Finally, when the clinician is satisfied that all has been done that can be done, the patient should be given the opportunity to both see the dentures in place and to comment on their comfort at this stage. Patients should be instructed on the insertion and removal of their new denture(s), and the need for careful handling of delicate components should be emphasised. The patient must be alerted to the likelihood of initial discomfort and habituation difficulties, and given careful instructions regarding the use and home care of their dentures. In particular, the patient should be reminded of the need to maintain good oral hygiene and to ensure the health of the remaining natural teeth and soft tissues. These warnings and instructions should be given verbally and reinforced in written form by means of an instruction leaflet. It essential that the patient be reviewed at a follow-up appointment arranged for, ideally, not more than one week later. First Inspection or Review At the review appointment, a note should be made of the patient’s experiences or complaints. With these in mind, the denture bearing areas should be examined for signs of denture trauma, as evidenced by inflammation or ulceration. The tissues should be examined, even in the absence of patient complaints, since many patients may be unaware of pressure areas, possibly due to a relatively high threshold of pain. Relieving adjustments to the peripheries or fitting surface of the dentures should be made in the light of the visual examination and the patient’s complaints. In cases where the patient has not been able to wear the dentures, sore areas may have healed to the point of not providing any evidence of trauma. In such cases, pressure indicating paste or other suitable material may be used on the fitting surface of the saddles to indicate areas of excessive pressure on the tissues. Adjustments should continue until the patient reports an improvement. The occlusion and articulation should be assessed again at this stage, and adjusted and refined if necessary. The nature and extent of the adjustments made should be recorded in the casenotes to make follow-up easier. Depending on the patient’s experiences and the amount of adjustment required, one or more further inspection appointments may be necessary. The patient should continue to be seen until they can manage with their dentures perfectly satisfactorily. When the time comes to discharge the patient at the end of treatment, the importance of attending for regular review in the future should be impressed upon the patient. Reline Procedures for RPDs These are applicable only to acrylic partial dentures and to free end saddles of Co-Cr dentures, it is not possible to reline cobalt chromium major connectors. The materials available are the same as for complete denture reline (see above). The procedure is analogous to that used for complete denture relines. Impressions are made by adding light or medium bodied silicone to the fitting surface of the denture to be relined, with the teeth and dentures in occlusion while the material is setting. When the material has set the denture should be removed and the fitting surface inspected to make sure that it is adequate. It is then replaced in position in the mouth and an impression is taken over the denture and the natural teeth using alginate in a stock impression tray (this is sometimes called a ‘pick-up’ impression). The denture containing the reline impression together with the alginate pick-up impression are sent to the laboratory along with the laboratory prescription. Immediate dentures Immediate dentures are used in making the transition from the natural to the artificial dentition. The difficulties in making this transition should not be underestimated by the patient or clinician. It is important that patients’ are aware of the advantages and disadvantages associated with this clinical procedure and obtaining informed consent is essential. An immediate denture is a denture that is made prior to extraction of natural teeth and which is inserted into the mouth immediately after the extraction of those teeth, it is therefore made to cover the resulting extraction sockets. Immediate dentures are seen as a means of the patient avoiding the social embarrassment of being without natural teeth, especially in the aesthetic zone. Because the denture is made to cover parts of the mouth before teeth are extracted it is only possible to estimate the morphology of those areas post-extraction. This is done by carefully removing stone teeth from the master cast and then carving the cast in those areas to the anticipated shape and size of the resulting tissues after extraction of those teeth. It can be appreciated that this can result in a less than ideal fit of the denture if the shape of the post-extraction sites differ from what was expected. This outcome can be minimised by providing the technician with the periodontal pocket depths of the teeth to be extracted, the deeper the periodontal pocketing the more extensive the tissue change is likely to be after extraction. A significant disadvantage associated with immediate dentures are the rapid changes that occur in the mouth following extraction. These mean that immediate dentures are expected to require adjustments and temporary relining procedures, followed by definitive relining or replacement approximately 6 months-1year after extractions. This adds significantly to the financial costs. There is insufficient space here to cover the myriad of possibilities involved in planning and providing immediate dentures the student is directed to read and appraise the recommended literature (St George G, Hussain N, Welfare R. Dent Update 2010; 37: 82–91; and St George et al Dent Update 2010; 37: 154–160) which provides more information on this topic. When providing immediate dentures in LUDH it is necessary to liaise with Oral Surgery and the following advice must be followed when arranging appointments: This advice has been produced in order to facilitate the treatment of patients who require the extraction or the surgical removal of teeth and the fit of an immediate prosthesis. Patients who require this treatment need to be carefully treatment planned to ensure that they are fully aware of the risks/benefits of extractions and the replacement by immediate prosthesis. In particular, if the treatment plan involves several stages, with addition onto existing dentures followed by the new dentures, patients should be informed of the likely timescales, the number of appointments, and the potential need for adjustments and relines etc. If there are several stages of extractions, the extraction pattern should be clearly set out in the clinical notes. Managing your patients in the appropriate manner is a key aspect of professionalism. Routine Extraction (one or more) teeth 1. You should present the completed paperwork to the Oral Surgery staff before arranging any appointment(s) for the patient. When presenting you will need:  Up to date RMH (pre & post-operative management should be considered in case of any RMH before any appointments are arranged i.e warfarin and INR).   Valid treatment plan signed by a member of staff.  Consent form completed and signed by patient and member of staff.  Referral form completed and signed by member of staff.  Diagnostic radiograph(s) of the tooth/teeth to be extracted appropriate for extraction assessment i.e. with the apex and any close laying anatomical structures clearly visible  An expected completion date for the denture Note: Patients will not be booked onto oral surgery for treatment without appropriate radiographs or valid consent 2. On the date of the appointment, prior to the extractions, the immediate prosthesis should be collected from the laboratory, inspected to check the correct teeth have been added and that the prosthesis is ready to be fitted. 3. Ideally you should try to accommodate the patient within one of your own extraction sessions, if this is not possible, you may attend during white space- please contact David Thornton in advance to prevent over booking of clinic. 4. Immediate prosthesis extraction appointments MUST NOT be made on a Friday, as there is no on-call/out of hours service at LUDH for the patient should there be an issue over the weekend. It is also advisable to avoid the last two weeks of term. 5. Prior to any extraction the prosthesis should be located in the mouth to assess that the replacement teeth have been added in roughly the right position. 6. Following the extractions, any minor adjustments required for fitting of the prosthesis will be undertaken in the Locals department. However if any substantial issues occur, then the member of staff from Oral Surgery will liaise with the Restorative tutor on Planning and Prevention Clinic (PPC), or on the Restorative teaching clinic. 7. A review appointment to assess the comfort of the patient should be arranged within 1-2 weeks during your timetabled Restorative sessions. Requests for extra Restorative sessions to review the denture will only be accepted in exceptional circumstances. Complex Extractions or complicated RMH The prosthesis should be inspected and ready to fit. 1. You should present the completed paperwork to the Oral Surgery staff before arranging any appointment(s) for the patient.   Up to date RMH.  Valid treatment plan signed by member of staff  Consent form completed and signed by patient and member of staff.  Referral form completed and signed by member of staff.  Diagnostic radiograph(s) of the tooth/teeth to be extracted appropriate for extraction assessment i.e. with the apex and any close laying anatomical structures clearly visible  An expected completion date for the denture 2. Your patient may require an assessment appointment to discuss their treatment needs. Your tutor will advise if this is required. Treatment will be carried out on the next available complex extractions session – this may not be for several weeks. Please arrange for the case notes and the prosthesis to be available to the clinic for this session e.g. Appointments on a MONDAY will need the case notes and prosthesis made available for the FRIDAY before. 3. Immediate prosthesis surgical extraction appointments MUST NOT be made on a Friday, as there is no backup for the patient should there be an issue over the weekend. 4. Depending on your timetable and year of study, you may or may not complete the treatment yourself. 5. If you are available to attend the MOS/Sedation session to fit the prosthesis (due to white space) please liaise with the appropriate member of the Oral Surgery staff. However, requests for timetable changes cannot be accommodated. If you are not attending, it is your responsibility to inform the member of oral surgery staff and ensure the prosthesis is in the department prior to clinic commence. 6. You must ensure a review appointment has been arranged to assess the comfort of the prosthesis within 1-2 weeks during your timetable Restorative sessions. Requests for extra Restorative sessions to review the denture will only be accepted in exceptional circumstances. Sedation or GA required If your patient needs a GA for treatment, a member of restorative staff will need to refer them to an Oral Surgery Consultant clinic for arrangements to be made. You may need to contact the patient following the consultation to arrange for them to pick up the dentures prior to the GA extractions. A review appointment to assess the comfort of the patient should be arranged within 1- 2 weeks during your timetable Restorative sessions. Appendix 1 Clinical-Laboratory Sequence: Complete Dentures Clinical: Treatment planning, first impressions Informed consent. Laboratory : cast impressions, produce special trays Clinical: second impressions. Laboratory: cast second impressions produce wax registration rims Clinical: register jaw relationships select artificial teeth. Laboratory: set anterior & posterior denture teeth for wax trial Clinical: try-in waxed trial dentures. Laboratory: either process wax trial dentures if satisfactory or rearticulate/reset teeth for 2nd wax trial [retry] Clinical: insert finished dentures Clinical: Review Appendix 2 Clinical – Laboratory Sequence Copy Dentures Involves no/little changes in occlusion/OVD Visit 1 Copy box impressions Wax occlusal wafer if needed Shade of denture teeth Return dentures to patient Lab request for wax try-in Visit 2 wax try-in Closed mouth wash impressions if satisfactory Request to laboratory for finished dentures Insertion of copy dentures. Usual aftercare instructions and follow up Appendix 3 Clinical-Laboratory Sequence Copy Dentures Involves changes in occlusion/OVD Copy box impressions Return dentures to patient request lab to pour copy mould with modelling wax in tooth spaces & self-cure acrylic bases Register jaw relationships using the wax-acrylic copies. Usually adding wax to occlusal surfaces to increase OVD by the desired amount. Select shade of teeth. Request wax try-in for next visit Wax try-in if satisfactory then closed mouth wash impressions in wax trial copies. Request finish from lab Insertion of ‘modified’ copy dentures. Usual aftercare instructions and follow up Appendix 4 Typical Clinical-Laboratory Sequence Immediate Dentures Clinical:Treatment planning, first impressions Laboratory: cast first impressions, produce special trays Determine extractions & extraction sequence. Informed consent for extractions. Second impressions Jaw registration. Depending on occluding teeth might require registration rims. Select denture teeth. If appropriate and possible depending on teeth that are already missing a wax try-in to confirm occlusion etc. Extractions & denture fit as appropriate. Arrange follow-up Follow-up : 24 hours (depends on clinical factors not always required) 1 week, 1 month, 3 months, 6 months, BUT depend on individual patient factors Appendix 5 Typical Clinical-Laboratory Sequence for Immediate Addition to existing RPD Alginate Impression in stock tray with partial denture in situ. The impression with the denture in place is sent to the lab with the prescription. Also Impression of opposing arch (+ any denture.) Require tooth shade Inform lab which tooth is being extracted & added to denture Finished denture returned from lab with tooth added. Make sure the correct tooth has been added. Proceed to extract the tooth in question insert the denture following normal procedures Follow up as for immediate denture Appendix 6 Appendix 7