them accordingly. Teeth may also present with mobility because of occlusal trauma, especially if there is a lack of posterior support. This is unlikely to improve without the provision of a removable prosthesis to replace posterior units.
Gag reflex – Can the denture-bearing area and connector sites be palpated without eliciting a gag reflex? If not, where are the trigger zones? These are most often the dorsum of the tongue, or the posterior palate.
Ulceration – Are there any existing signs of ulceration, and do they correspond to the extensions of a prosthesis?
Temporomandibular disorder – Are there currently any signs of muscle pain or temporomandibular joint derangement?
Dry mouth – Does the patient complain of a dry mouth? Is this medication-induced? A dry mouth will significantly increase the risk of root caries and gingivitis when wearing a partial denture.
Retained roots – Could these be retained as overdenture abutments and what is the space between root surface and opposing tooth? Do not forget that healthy retained roots will prevent alveolar resorption, improve proprioception and chewing ability. Further, there is a large psychological benefit to retaining natural teeth and tooth roots.
Worn or compromised teeth – Could worn teeth be restored directly or indirectly prior to the provision of removable prostheses? Could the removable prosthesis overlay the worn teeth to restore their form and function? Can an extra coronal restoration be placed with elements that will facilitate partial denture stability and retention, such as milled shoulders, rest seats and guide planes. These are questions that are often overlooked when planning removable partial prostheses and will be discussed further later in the book.
Ridge assessment
Ridge form may be less critical with removable partial dentures, particularly if there are bounded saddles – but atrophic ridges and thin fibrous bands of tissues should still be noted, because these can cause problems, especially with free-end saddle presentations.
Partial denture classification
In relation to ridge and saddle configuration, it is important to be able to communicate the type of partial denture effectively to colleagues and the wider dental team. Chapter 28 describes the Kennedy partial denture classification system, which is probably the most ubiquitous. It is also very important to decide whether you will maintain the natural tooth contacts in the current intercuspal position, or whether you will be changing (or reorganising) the occlusion. It will not be possible to plan or design a partial denture effectively without deciding this first. This is covered further in Chapter 23.
Assessment of existing prostheses
Partial dentures should be assessed in the same way as for complete dentures in relation to retention and stability. It is, however, also important to appraise the connector design, and the path of insertion, even if the dentures are made totally in acrylic. Material choice and connectors are discussed later in Chapters 28 and 31.
Radiographic assessment
As well as a thorough periodontal and restorative assessment, it is important to assess potential abutment teeth radiographically for any potential periapical pathology and to assess the bony support available. It is also important to assess the angulation of the long axis of the tooth. Non-axially loading a tooth can exacerbate occlusal trauma and bony loss.
7 Factors complicating success
Prognosis and justification
Each diagnosis and treatment plan should be qualified with a prognosis – an indication of the likely outcome of the condition, or the proposed treatment. Without this information, the patient is unable to make an informed choice about which treatment modality to pursue – and so it is important to remember to discuss this and record the discussions within the patient notes. Just as important as the prognosis is the justification for how this decision is reached. A comprehensive and thoroughly recorded assessment will facilitate this process. The factors below are considered to be risk factors when constructing removable prostheses (Figure 7.2).
Risk factors
Patient factors
Patient confusion or uncertainty – If patients are unsure about why they are receiving a prosthesis, or they feel that there is little need, then they are less likely to wear the finished product. You must be clear about what your treatment aims are, and this should be checked and reinforced at each patient appointment.
Pain over the full denture-bearing area (DBA) – An ache or a burning sensation over the entire DBA (on either arch) can be difficult to diagnose accurately and manage. This may happen if the occlusal vertical dimension is excessive, meaning that the denture bearing area is perpetually overloaded. Leaving one or both dentures out can help to confirm the diagnosis. This type of pain can also present if there is an allergy or an intolerance to materials in the denture base. If this is suspected, it will be important to send the patient for patch testing for sensitivity to denture-base materials.
Immediate intolerance – It is always a concern when the patient is unable to retain a prosthesis in the mouth for any time at all. Occasionally this may be because of acute trauma from the prostheses, making fully seating them painful. However, it is often the case that patients are reluctant to insert their prostheses – and begin to reject them before they are even fully inserted into the mouth. This rejection may also be accompanied with a gag reflex, which is discussed further below. There are often psychosocial problems that will complicate the acceptance of a removable prosthesis and it is important that the patient feels comfortable enough to highlight any concerns. You must also be sensitive to the fact that some patients may have experienced traumatic events in the past that have manifested as oral intolerances. Be prepared on some occasions to refer patients, via their general practitioner, for counselling.
Received multiple consecutive sets – Patients that present with a bag full of previous dentures should be assessed very carefully. The previously failed prostheses are usually a warning sign that risk factors have been missed – it is also often the case that patient expectations have been mismanaged. In this case, just assess the set of dentures that the patient prefers or wears most frequently.
Lack of recent prosthetic experience –