Replacement of Missing Teeth with Fixed Prostheses

1 R E S T O R A T I V ER EDS ETNO TR IASTTI RV YE D E N T I S T RY. Replacement of Missing Teeth with Fixed Prostheses KEN HEMMINGS AND ZOE HARRINGTON. survival time of 7 years 10 Abstract: This article explores the various treatment options available to replace Possible designs include: cantilever, Fixed - Missing Teeth with a Fixed prosthesis. It discusses the requirements for each treatment Fixed and hybrid where one of the retainers modality and its associated advantages and disadvantages. is conventional. Dent Update 2004; 31: 137 141 A major advantage of resin-bonded Prostheses is that minimal tooth Clinical Relevance: Patients generally do not consider a removable prosthesis to preparation is required and so they can be an acceptable long-term solution to tooth loss, so knowledge of treatment options is usually be considered a reversible essential for good clinical practice.

2 Procedure. As dentine preparation is not involved, the integrity of a young pulp is maintained. Other advantages include the fact that anaesthesia is not normally l Conventional bridge;. T oday, numerous types of Fixed Prostheses are available to replace Missing Teeth . Developments in the field of l Implant. required, soft tissues are not disturbed which simplifies impression procedures, and margins are supragingival, facilitating implantology and adhesive dentistry have plaque removal. A failure rarely results in increased the options available for the None any adverse long-term consequences for partially edentulous patient but have also The Replacement of Missing Teeth may not the patient unless periodontal or made treatment planning more complex.

3 Always be indicated or possible. Kayser orthodontic splinting has been employed. However, it still remains important to stated that oral function was adequate in Disadvantages include the fact that identify a positive need' to restore a shortened dental arches where at least aesthetics may be compromised by shine space and to undertake a cost-benefit four occluding premolar units were left, through' of metal retainers, resulting in analysis for any proposed restoration depending on the age of the patient and discoloration of the abutment Teeth . This not only in financial terms but also in preferably in a symmetrical Love situation can be improved with the use of biological cost to tooth structure and the and Adams found that unfavourable opaque luting cement but this can, in turn, supporting tissues.

4 Movement of neighbouring Teeth into an result in a loss of translucency and a extraction site did not necessarily occur highly visible white line if used where and was unlikely if it had not occurred there is incisal coverage. Although it is Fixed OPTIONS FOR TOOTH within 5 years of the This does possible to assess the appearance of the Replacement not help the practitioner immediately after bridge with try in' pastes prior to Fixed options for tooth Replacement removing a tooth. However, this evidence cementation, there is no trial phase to test include the following: is useful when assessing treatment needs for patients who have had an edentulous l None; space for a number of years (Figure 1).

5 L Resin-bonded bridge;. Resin-bonded Bridge Ken Hemmings, BDS, MSc, DRD RCS, MRD. RCS, FDS RCS, Consultant in Restorative Dentistry with improvements in the field of and Zoe Harrington, BDS, MFGDP(UK), MSc, adhesive dentistry, resin-bonded MFDS RCS, Specialist Registrar in Restorative bridgework has become a viable option for Dentistry, Eastman Dental Hospital & Institute, the long-term Replacement of Missing 256 Gray's Inn Road, London WC1X 8LD. Teeth . One study reported a median Figure 1. Shortened dental arch. Dental Update April 2004 137. R E S T O R AT I V E D E N T I S T RY.

6 The metal and composite resin-luting agent. The commonest reason for failure is through debonding at the tooth-resin- metal interface. This typically occurs when the cement lute is subjected to shear forces created by unfavourable occlusal loading. Class II division 2 incisor relationships and significant bruxism are Figure 2. Resin-bonded bridge replacing the relative contra-indications to the use of Figure 3. Posterior resin-bonded bridges. upper incisors. resin-bonded bridges and should be considered higher risk when these necessary to prepare grooves or boxes to any occlusal changes.

7 Generally, tooth situations are restored with such a enhance resistance form (Figure 3). movement will occur within six to nine prosthesis. The minimum number of months if the bridge is fitted high'. Most abutments should be used and occlusal bridges are cemented in this way. contacts should be entirely on the metal Conventional Bridge However, occasionally planned wings, since contact distributed between The lifespan of conventional bridgework adjustment of the opposing tooth may be metal and tooth will cause the tooth to is thought to be in the region of 15 to 20.

8 Necessary at the time of fit for patients move away from the retainer, resulting in Designs include: Fixed - Fixed , Fixed - unable to tolerate occlusal change. Lower failure of the bond. If this occurs on only movable, cantilever and spring cantilever. incisor reduction should be flat and not one wing in a Fixed - Fixed design bridge, Advantages of conventional bridgework angulated, limiting the occlusal contact caries may go undetected under that wing, are that it provides a predictable and area to control the protrusive pathway and resulting in disastrous consequences.

9 The aesthetic result. However, it is very reduce wear. use of double abutments does not destructive of tooth structure, which can Resin-bonded bridges require the same increase retention in resin-bonded lead to problems with the endodontic planning as any other Fixed prosthodontic bridgework and is generally not indicated, status of abutment Teeth . Root canal procedure and should not be considered apart from occasionally in post- treatment once a bridge is cemented is as a faster alternative to conventional orthodontic and periodontal splint cases. likely to necessitate a remake because the methods.

10 They can be prescribed where There is no evidence to indicate the length access preparation weakens the there is sufficient enamel and the of span that may be restored using this underlying dentine or It is therefore aesthetics of the abutment Teeth is technique, but the longer the span the recommended that endodontic treatment satisfactory. It should be noted that the more rigid the framework must be (Figure be carried out for Teeth of dubious vitality occlusal coverage required when replacing 2). prior to bridge construction. Teeth with a posterior Teeth can be particularly A second reason for failure is very doubtful prognosis may be better unsightly.