LITMIR.BIZ

Скачать книгу

can be improved during the working impression with a border moulding material to ensure that its full anatomy is captured.

      Photograph 2

      Intraoral access here is slightly restricted. The full DBA can be palpated without pain or gagging. The mucosa looks shiny and dry, and clinically there are signs of a dry mouth; the mirrors stick to the mucosa, and food debris accumulates at the denture borders. It may be necessary for the patient to consider a saliva substitute in order to promote effective adhesion and cohesion, and a border seal. The ridge is well defined and rounded (Class III), but the sulcal depth reduces significantly towards the posterior aspects. The palate is relatively shallow and broad – shallow ridges and a shallow palate mean that the denture may have a compromised stability. The muscle attachments insert onto the crest of the ridge – this is the other extreme of how attachments may present. The challenge here is ensuring they are accommodated for, without compromising the border seal. The labial portion of the anterior ridge presents with a significant undercut and it is worth considering at the assessment stage whether a defined path of insertion is possible, or whether the permanent base should be modified with permanent soft liner to allow the ridge to be atraumatically engaged.

      Photograph 3

      Intraoral access here is excellent. Palpation of the DBA in the palate beyond the posterior border of the existing prosthesis results in a gag reflex. There is no pain on palpation. The ridge is well formed (Class III) but lacks some definition in the premolar regions, where it presents with a knife edge (Class IV). Once again, muscle attachments are situated near the base of the sulcus, so attention to detail during the working impression will be important. It is possible to see the posterior extent of the existing denture, which is short by at least 15 mm. It is also possible to see the limited degree to which the denture base wraps around the tuberosities. Both of these features will significantly compromise the stability and retention, and perpetuate the gag reflex. A thin band of tissue exists along the crest of the ridge from incisor to premolar on the patient's right-hand side, and this should be accounted for in the working impression; in order to avoid the denture ‘nipping’ the tissues, the impression should be taken in zinc oxide eugenol, and the borders of the thin tissue ridge should be filleted away with a scalpel. Once again, the labial portion of the anterior ridge presents with a significant undercut and it is worth considering at the assessment stage whether a defined path of insertion is possible, or whether the permanent base should be modified with permanent soft liner to allow the ridge to be atraumatically engaged.

      Lower edentulous ridges

      Photograph 4

      The full DBA can be palpated without any pain, although contact with the posterior lateral borders of the tongue elicits a gag reflex. The ridge is atrophic with a knife edge presentation (Class IV). A thin fibrous band of tissue runs along the entire crest of the ridge – and this should be accounted for in the working impression; in order to avoid the denture ‘nipping’ the tissues, the impression should be taken in zinc oxide eugenol, and the borders of the thin tissue ridge should be filleted away with a scalpel. Muscle attachments are low and there is only a moderate sulcal depth anteriorly when the lip is retracted. The tray will need to be carefully adjusted here to ensure it is not overextended.

      Photograph 5

      The full DBA can be palpated here without eliciting pain or a gag reflex. The tissues are fibrous anteriorly, and it is possible to see the folds of tissue in the photograph. The ridge is atrophic (Class V) but presents with an identifiable fibrous crest. This is thicker than in photograph 4, and so is unlikely to fold over when the denture is seated. No special interventions are required in that regard. There is little identifiable sulcus anteriorly and so the tray will need to be carefully adjusted here – and it may even be the case that a purposefully mucostatic or mucocompressive impression (depending on the assessment) is taken to account for the anterior fibrous tissue. Ulceration is visible in the buccal and labial sulci, and it is important to ensure that this is resolved prior to working impressions.

      Photograph 6

      The full DBA can be palpated without pain or gagging. The ridge is firm, well formed and generally rounded at the crest – although there are undercut aspects around the buccal aspect. This would be graded as Class IV. Muscle attachments are relatively low and there appears to be a reasonable depth to the labial sulcus. Avoid thinking that these cases are straightforward to treat – it is sometimes the case with well-formed ridges that they pose problems in terms of ridge pain after fitting of the dentures.

6 Patient assessment for partial dentures

An assessment for a partial prosthesis begins in much the same way as for a complete denture – why does the patient want the treatment, and what are the risk factors that can alter your chances of success? The main obvious difference, however, is the presence of standing natural teeth. The health and prognosis for these teeth must be adequately assessed in order to plan the treatment effectively for removable partial prostheses – and whilst the method of partial denture design will be covered later, the necessary clinical information and indices will be mentioned here as part of the initial assessment stage.

      The patient and the rationale for treatment

       Why does the patient want new or improved dentures?

       Do the current dentures cause pain?

       Is there any difficulty chewing or speaking?

       Are the dentures of a satisfactory appearance?

      Prosthodontic history

       What type of denture is the patient currently wearing?

       How old is the prosthesis and where was it/they made?

       For how many years has the patient been wearing partial dentures?

       How many prostheses has the patient received before?

       Is the patient willing to attend for the necessary appointments, including review appointments?

      Clinical examination

      Before considering removable partial prostheses, it is important to carry out a full and comprehensive extra- and intraoral assessment. The following aspects can then be considered.

       Intraoral access – Can the denture-bearing anatomy be palpated easily, and can any existing prostheses be easily inserted and removed from the mouth?

       Plaque control – Wearing removable partial dentures in the presence of poor plaque control poses a significant risk to the dentition, for the progression of root caries and soft tissue disease. If the basic periodontal examination (BPE) codes are anything but 0, you should be carrying out at least a plaque score and providing tailored oral hygiene instruction.

       Tooth mobility and periodontal pocket depths – Whether teeth are pathologically mobile or present with deep bleeding pockets is often overlooked during a partial denture assessment. It is often assumed that the expected future loss of teeth warrants an acrylic partial denture – in reality, it is important to determine which teeth might be capable of helping to support a removable

Скачать книгу