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References

Faigenblum M. Removable prostheses. Br Dent J. 1999; 186:273-276
Packer ME, Davis DM. The long-term management of patients with tooth surface loss treated using removable appliances. Dent Update. 2000; 27:454-458
Hemmings KW, Howlett JA, Woodley NJ, Griffiths BM. Partial dentures for patients with advanced tooth wear. Dent Update. 1995; 22:52-59
Kayser AF. Shortened dental arches and oral function. J Oral Rehabil. 1981; 8:457-462
Kanno T, Carlsson GE. A review of the shortened dental arch concept focusing on the work by the Kayser/Nijmegan group. J Oral Rehabil. 2006; 33:850-862
Jepson NJA, Thomason JM, Steele JG. The influence of denture design on patient acceptance of partial dentures. Br Dent J. 1995; 178:296-300
Addy M, Bates JF. Plaque accumulation following the wearing of different types of removable partial dentures. J Oral Rehabil. 1979; 6:111-117
Steele JG, Treasure ET, O'Sullivan I. Adult Dental Survey 2009: transformations in British oral health 1968–2009. Br Dent J. 2012; 213:523-527
Feine JS, Carlsson GE, Awad MA The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients. J Prosthet Dent. 2002; 88:123-124
Thomason JM, Heydecke G, Feine JS, Ellis JS. How do patients perceive the benefit of reconstructive dentistry with regard to oral health related quality of life and patient satisfaction?. Clin Oral Implants Res. 2007; 18:168-188
Toolson BL, Smith DE. A five-year longitudinal study of patients treated with overdentures. J Prosthet Dent. 1983; 49:749-756
Basker RM, Harrison A, Ralph JP, Watson CJ. Overdentures in General Dental Practice, 3rd edn. London: British Dental Association; 1993
Kay WD, Abes MS. Sensory perception in overdenture patients. J Prosthet Dent. 1976; 35:615-619
Crum RJ, Rooney GE Alveolar bone loss in overdentures: a 5-year study. J Prosthet Dent. 1978; 40:610-613
Van Waas MA, Jonkman RE, Kalk W, Van't Hof MA, Plooij J, Van OSJH. Differences two years after tooth extraction in mandibular bone reduction in patients treated with immediate overdentures or with immediate complete dentures. J Dent Res. 1993; 72:1001-1004
Rissin L, House JE, Manly RS, Kapur KK. Clinical comparison of masticatory performance and electromyographic activity of patients with composite dentures. Overdentures and natural teeth. J Prosthet Dent. 1978; 39:508-511
Langer Y, Langer A. Root-retained overdentures: Part I – Biomechanical and clinical aspects. J Prosthet Dent. 1991; 66:784-789
Toolson LB, Taylor TD. A 10-year report of a longitudinal recall of overdenture patients. J Prosthet Dent. 1989; 62:179-181
Toolson LB, Smith DE. A 2-year longitudinal study of overdenture patients. Part 1. Incidence and control of caries on overdenture abutments. J Prosthet Dent. 1978; 40:486-491
Ettinger RL, Taylor TD, Scandrett FR. Treatment needs of overdenture patients in a longitudinal study: five-year results. J Prosthet Dent. 1984; 52:532-536
Budtz-Jorgensen E, Theilade B, Theilade J. Quantitative relationship between yeasts and bacteria in denture-induced stomatitis. Scand J Dent Res. 1983; 91:134-142
Anderson JN, Bates JF. Cobalt chromium partial denture. A clinical survey. Br Dent J. 1959; 107:57-62
Witter DJ, Van Elteren P, Kayser AF. Oral comfort in shortened dental arches. J Oral Rehabil. 1990; 17:137-143
Tallgren A. Changes in adult face height due to ageing, wear and loss of teeth and prosthetic treatment. Acta Odont Scand. 1957; 15
Thompson JL, Kendrick GS. Changes in the vertical dimension of the human skull during the third and fourth decades of life. Anat Rec. 1964; 27
Murphy T. Compensatory mechanisms in facial height adjustment to functional tooth attrition. Aust Dent J. 1959; 4:312-323
Berry DC, Poole DFG. Attrition: possible mechanisms of compensation. J Oral Rehabil. 1976; 3:201-206
Russell MD. The distinction between physiological and pathological attrition: a review. Ir Dental Assoc. 1987; 33
Overdentures – theory and technique. J Am Dent Assoc. 1983; 86:853-857
Lord JL, Teel S. The overdenture: patient selection, use of copings and follow-up evaluation. J Prosthet Dent. 1974; 32:41-51
Morrow RM, Feldman EE, Rudd KD, Torvillion HM. Tooth-supported complete dentures: an approach to preventive prosthodontics. J Prosthet Dent. 1969; 21:513-522
Dolder EJ. The bar joint mandibular denture. J Prosthet Dent. 1961; 11:689-707
Harran Ponce E, Canalda Sahli C, Vilar Fernandez JA. Study of dentinal tubule architecture of permanent upper premolars: evaluation by SEM. Aust Endo J. 2001; 27:66-72
Zaslansky P, Zabler S, Fratzl P. 3D Variations in human crown dentin tubule orientation: a phase-contrast microtomography study. Dent Mater. 2010; 26:e1-10
Budtz-Jørgensen E. Prognosis of overdenture abutments in elderly patients with controlled oral hygiene. A 5-year study. J Oral Rehabil. 1995; 22:3-8
Wise MD.London: British Dental Association; 1986
Ramfjord SP, Ash Maj M. Reflections on the michigan splint. J Oral Rehabil. 1994; 21:491-500
Ramfjord S, Ash MM. Biteplates, biteplanes and occlusal splints, 3rd edn. Philadelphia: WB Saunders Co; 1983
Howat AP, Capp NJ, Barrett NVJ. Occlusal splint therapy.London: Wolfe; 1991
Carr AB, Brown DT. McCracken's Removable Partial Prosthodontics, 12th edn. Oxford: Elsevier Mosby; 2011
Public Health England. Delivering better oral health: an evidence-based toolkit for prevention. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/605266/Delivering_better_oral_health.pdf (Accessed March 2017)
Hussey DL, Linden GJ. The efficacy of overdentures in clinical practice. Br Dent J. 1986; 161:104-107
Narhi TO, Ettinger RL, Heilman JR, Wefel JS. Salivary fluoride levels in overdentures wearers after topical fluoride gel application. Int J Prosthodont. 1997; 10:553-561

Tooth wear guidelines for the bsrd part 3: removable management of tooth wear

From Volume 45, Issue 8, September 2018 | Pages 687-696

Authors

Ken Hemmings

BDS MSc DRDRCS MRDRCS FDS RCS ILTM FHEA

Consultant in Restorative Dentistry, Eastman Dental Hospital & Institute, 256 Gray's Inn Road, London WC1X 8LD.

Articles by Ken Hemmings

Angharad Truman

BDS (Hons), MFDS, M Pros, FDS (Rest Dent) RCSEd, PGCME, FHEA

Specialty Registrar in Restorative Dentistry, Bristol Dental Hospital

Articles by Angharad Truman

Sachin Shah

BDS, MFDS RCS, MClin Dent(Pros), MRD RCS

Specialist Prosthodontist in private practice/Clinical Teaching Fellow, Eastman Dental Hospital and Institute, 256 Gray's Inn Road, London, WC1X 8LD

Articles by Sachin Shah

Ravi Chauhan

MDDr, MSc, MJDF RCS(Eng), MFDS RCS(Edin)

Specialty Registrar in Restorative Dentistry, King's College Dental Hospital, London, UK

Articles by Ravi Chauhan

Article

Removable prostheses can be used alone or in combination with fixed prosthodontic treatment to manage tooth wear (TW). It is an accepted mode of treatment that can fulfil the aims of restoring the appearance, function and/or speech of patients with worn dentitions.1,2

The lack of coronal tooth tissue in cases of severe tooth surface loss can make fixed prosthodontic treatment more challenging and less predictable. Removable prosthodontic treatment may be more appropriate in these cases, especially when the additional time and cost associated with fixed prosthodontic treatment is taken into account. The remaining coronal tooth tissue can be used to support, retain and/or stabilize a removable prosthesis. A partially dentate patient with advanced tooth wear may add more credence to this form of treatment.

Patients will need to be made aware of the limitations associated with removable appliances, the added maintenance and potential risks to the remaining dentition. Patient compliance, adaptation and managing expectations will also be key to providing a successful outcome.

Indications for removable management of tooth surface loss

  • Severe generalized tooth surface loss;
  • Severe generalized tooth surface loss in a partially dentate patient with long edentulous spans and/or distal extensions;
  • Tooth surface loss in a patient well adapted to wearing removable prostheses;
  • Patients who may not be suitable for fixed prosthodontic treatment due to the following reasons:
  • - Worn teeth compromised by periodontal disease and/or extensive caries;
  • - Unrestorable teeth – vertical root fractures, horizontal/oblique fractures to bone crest, caries to bone crest, failed endodontics;
  • - Concurrent soft tissue defects;
  • - The additional time and cost involved.
    •

    Contra-indications for removable management of tooth surface loss

    Patients unable to tolerate a removable prosthesis.

    Aims of removable management

  • Restore appearance;
  • Restore function;
  • Protect the remaining dentition;
  • Re-establish the occlusal vertical dimension if this has been reduced.

    • Definitions

    The following terms will be used to describe the various removable appliances:

  • Overdenture: a denture that replaces the worn or missing teeth with prosthetic teeth and an acrylic flange3 (Figure 1).
  • Onlay denture: a denture that covers the occlusal or incisal surfaces of the abutment teeth3 (Figure 2).
  • Overlay denture: a denture that covers the worn teeth with a full labial veneer facing3 (Figure 3).
    • Figure 1. (a, b) Overdenture abutments can be vital or non-vital teeth. Ideally, they should be 2mm supra-gingival. Re-inforced acrylic has been used. Often a metal strengthener is needed for durability.
    Figure 2. (a, b) Onlay provisional denture to test an increase in the OVD. The onlays have to be refined in the mouth for an accurate fit. A low lip line made the appearance acceptable for this patient.
    Figure 3. (a, b) Anterior overlays on a metal framework partial denture. Refinement in the mouth is usually necessary for accuracy of fit and a good appearance.

    Combinations of the above can be used on the same prosthesis.

    Removable management

    Severely worn teeth cannot always be restored through fixed prosthodontic means. They may be present in combination with long edentulous spans that also require soft tissue replacement. Removable prostheses can help to replace soft tissues and provide lip support. They can also be designed to have further teeth added to them in the future.

    Not all teeth necessarily require replacing. Patients can function well with 10 pairs of occluding units or a second premolar to second premolar occlusion.4,5 Patients presenting with severe tooth wear often do so because it affects their anterior teeth. Compliance with removable prostheses has been shown to be better when they replace and/or restore the anterior dentition.6

    Despite the benefits of removable prostheses, they can lead to increased levels of plaque accumulation when oral hygiene is inadequate.7 It is therefore critical that patients are given clear instructions on maintaining excellent oral hygiene and advised to leave their removable prostheses out at night. Failure to do so may quickly lead to failure of strategic abutment teeth and present further challenges for the patient and clinician.

    Managing patient expectations

    It is important for patients to have realistic expectations of removable prostheses. They must be informed of their limitations from the outset so that they do not attribute this to inadequate clinical work.

    Treatment options

    Extracting the remaining teeth and providing complete dentures

    Patients are retaining more teeth for a longer period of time due to the increase in life expectancy, fluoride availability and improved oral hygiene practices.8 This increase in age, together with increasing expectations, means that patients often have a lower adaptive capacity and ability to manage complete dentures at an advanced age. Extracting the remaining teeth, no matter how heavily restored or worn, has therefore become a less frequently practised option. It can, however, still be a pragmatic option if there are only a few teeth remaining that are beyond saving, and if the patient is not suitable for complex treatment. Anecdotally, it is thought that many bruxist patients transform into maladaptive denture-wearing patients. The high occlusal loads lead to early mucosal trauma and ridge resorption. Careful planning and care at every stage during the process of making complete dentures will be required. An implant-supported mandibular overdenture can be considered as a further treatment option in this cohort of patients to facilitate and improve this transition.9,10 These will still be subjected to high occlusal load in bruxist patients.

    Complete or partial overdentures

    It can be more appropriate to reduce the teeth further when they are severely worn and provide either complete or partial overdentures. These appliances replace the worn teeth with prosthetic teeth and an acrylic flange. The following advantages can be gained from doing this:

  • Provide the psychological benefit of tooth retention, creating a more positive attitude to dentures;11
  • Maintain continued proprioceptive feedback with the preservation of periodontal mechanoreceptors;12,13
  • Decrease the rate of residual ridge resorption and therefore maintain added support and stability.14,15 They can also provide lip support if located anteriorly;
  • Can provide added retention, improved masticatory efficiency and better control of mandibular movements;16
  • Further retention can be gained from the addition of precision attachments such as magnets or stud attachments;
  • Replace soft tissue through the use of a flange;
  • Improve the crown-root ratio and therefore limit damaging lateral forces.

    • There are, however, disadvantages associated with this treatment option that include:

  • A reduction in the space available for the prosthetic teeth and denture base. This reduction can lead to weakness and the increased likelihood of developing a fatigue fracture;17
  • Caries affecting the overdenture abutments can be a problem due to plaque accumulation under the denture base if the patient does not have a good preventive regimen;11,18, 19, 20, 21
  • Similarly, poor plaque control can lead to periodontal breakdown;18
  • Severely worn teeth do not always require root canal treatment due to the continued deposition of secondary dentine. However, there is always a risk of pulp exposure when reducing teeth.

    • Complete or partial onlay or overlay dentures

    The occlusal or incisal surfaces of worn teeth can be restored with an onlay or overlay type appliance without a flange.

    Onlay type appliances can be useful for moderately worn posterior teeth to restore the surfaces of these teeth and re-establish the correct occlusal vertical dimension. The occlusal surfaces can be made of a cobalt-chromium alloy and can be made to be an integral part of the denture framework to increase their durability.

    The choice between an onlay or overlay design for anterior teeth will depend on the following factors:

  • The height of the upper lip in function and when smiling. An onlay type of design will not be aesthetic if the butt joint is visible in function and on smiling. An acrylic veneer terminating at the gingival margin will be more attractive in these situations.
  • The path of insertion of the denture. Gaining a favourable path of insertion for acrylic veneer facings may eliminate favourable undercuts for clasping posteriorly and needs to be considered when designing the denture.

    • Partial dentures in combination with adhesive or conventional fixed prosthodontics

    Teeth that have not been affected by wear can be modified so that they can help to retain, support and stabilize a removable prosthesis. The following features can be considered when designing the denture:

  • Preparation of guide planes on abutment teeth to limit the ways in which the denture can be displaced and provide added stability;
  • Additions can be made to teeth with composite resin to alter their contour and provide favourable undercuts for clasping;
  • Consider restoring teeth that have large plastic restorations with milled extra-coronal restorations that have guide planes, ledges and/or rest seats.

    • Damaging occlusal forces on worn anterior teeth restored with adhesive or conventional crowns should be considered if the partial dentures only replace posterior teeth. Compliance with wearing dentures is reduced in this cohort of patients.22,23

    Preliminary investigations

    The following should be investigated in relation to providing removable prostheses for tooth wear.

    Assessing the occlusal vertical dimension

    Restoring the worn dentition to the correct occlusal vertical dimension will form the basis of treatment. In the absence of tooth wear the free-way space remains constant due to the continued growth and increase in anterior facial height into middle age.24,25 Tooth wear, however, leads to the continued eruption of teeth so that the free-way space remains constant and so do the proportions of the face. This is commonly known as compensated tooth wear.26,27

    Non-compensated tooth wear occurs when the rate of the tooth wear is too fast for the physiological mechanisms of tooth eruption to keep up. There is therefore a resultant increase in free-way space and loss of occlusal vertical dimension.

    Patients with compensated tooth wear will usually have a complete dentition and treatment with removable prostheses will rarely be indicated.1 Partially dentate patients with loss of the posterior dentition and wear affecting the anterior teeth will usually present with non-compensated tooth wear and a loss of OVD, making it necessary to provide treatment with removable prostheses. These patients will often have an unacceptable occlusal plane and the following can be used to determine the correct occlusal vertical dimension:

  • The point of first contact along the retruded arc of closure (RAP) if there are unworn teeth posterior to the worn anterior teeth. This will be the retruded contact position (RCP) and may provide the required space to restore the worn anterior dentition;
  • Photographs of the patient's teeth prior to being worn;
  • Tooth display at rest and on smiling;
  • Amount of posterior prosthetic space required, if necessary;
  • Phonetics;
  • Use of a provisional denture for between 6 weeks and 6 months.

    • The recording of the OVD is usually carried out using occlusal registration rims. Edentulous patients will be less tolerant to changes in the occlusal vertical dimension than dentate patients (Figure 4).

    Figure 4. (a, b) Non-compensated tooth wear in a depleted dentition. Clinical appearance reproduced in mounted study casts. (c, d) Increase in OVD determined in the laboratory. Upper and lower wax tryins made. (e, f) Provisional upper and lower partial overdentures in place for patient approval.

    Assessing severely worn abutment teeth

    As mentioned earlier, a severely worn tooth does not necessarily need to be condemned. It can be retained as an overdenture abutment. The following factors need to be considered if a tooth is to be retained as an overdenture abutment:

  • The periodontal health of the abutment tooth. At least five millimetres of alveolar bone support has been recommended,28,29 together with an adequate band of attached gingival tissues.30
  • The height of the overdenture abutment should be one and a half to two millimetres above the gingival margin and dome-shaped.31 The reduction in crown/root ratio will reduce the mobility of the tooth.32
  • Reducing a tooth will expose more dentinal tubules and less calcified dentine, making the pulp more vulnerable to cariogenic bacteria.33,34 A good level of oral hygiene is therefore paramount. It has been shown that overdenture abutments can be maintained in older patients with a history of primary dental disease by four to five recall visits per year.35

    • Assessing spaces

    Spaces should be assessed in three dimensions that should include inter-occlusal, mesio-distal and bucco-palatal measurements. The following should be considered when making an assessment of the space:

  • The site and extent of spaces. Are the spaces bounded or free end saddles?;
  • Have any teeth drifted, tilted or over-erupted into the resulted space? This can be more readily assessed on a set of accurately mounted casts;
  • What is the condition of the soft tissues overlying the ridge?

    • Diagnostic phase

    Occlusal splints

    An upper, hard, heat-cured, full coverage acrylic splint with (provisional denture) or without teeth can be used in the diagnostic phase. They should provide even contact along the retruded arc of closure with anterior guidance on anterior teeth with posterior disclusion and canine guidance in lateral excursions.36 They can provide the following benefits:

  • Protect worn teeth from any further wear, especially if the original cause is attrition;
  • Break the proprioceptive feedback from periodontal mechanoreceptors resulting in muscle relaxation that will facilitate the accurate recording of the retruded axis position;37
  • Useful for testing tolerance to the planned changes in occlusal vertical dimension.38,39

    • Partial coverage splints should be avoided due to selective intrusion and extrusion of teeth. The resulting malocclusion can be difficult to correct.

    Provisional appliances

    Acrylic provisional appliances that have an overdenture, onlay and/or overlay design can be provided to test changes in occlusal vertical dimension, aesthetics, phonetics and function. They can also be used to test the patient's tolerance and adaptive capacity to removable appliances. They should be designed and made with the same care as a definitive denture. They can be modified (ie relined or adjusted) whilst abutment teeth are being prepared to receive extracoronal restorations or being built-up with composite resin prior to making the definitive dentures.

    Definitive dentures

    The ideal features of the provisional appliance should be carried forward to the definitive denture. These include the proposed changes to the occlusal vertical dimension and aesthetics. A wax try-in will be required if any further changes are proposed.

    The definitive denture should fulfil the following aims:

  • Increased durability;
  • Reduced bulk;
  • Improved cleansability;
  • Decreased maintenance.

    • The definitive denture should be designed prior to considering any irreversible changes to the abutment teeth. The changes to the abutment teeth can then be made taking into account the materials to be used to construct the definitive denture. The stability of dentures and patients' adaptation to them will be increased if guidance in excursions is maintained on the natural teeth. In the depleted dentition it is more likely that a bilateral balanced occlusion should be provided.

    Materials

    Denture base

    The retention of teeth as overdenture abutments will limit the amount of space available for the denture base and prosthetic teeth. This can therefore pose challenges when managing patients with wear.

    The ideal denture base should meet the following requirements:40

  • Accuracy of adaptation to the tissues with minimal volume change;
  • Dense, non-irritating surface capable of receiving and maintaining a good finish;
  • Thermal conductivity;
  • Low specific gravity;
  • Lightweight in the mouth;
  • Sufficient strength;
  • Easily kept clean;
  • Aesthetic acceptability;
  • Potential for future relining;
  • Low initial cost.

    • Denture bases can be metal- or resin-based.

    Acrylic resin bases need be at least two to three millimetres thick, can be aesthetic and easily adjusted and relined. They can, however, release internal strains that may lead to distortions and can be more prone to accumulate deposits, be bulky and less abrasion resistant.40 To counteract these shortcomings, some form of strengthening of the denture base should be considered.

    Metal-based dentures that can be cast in either gold, chrome or titanium alloys are more difficult to reline and adjust. They do, however, have the following advantages:

  • Can be cast more accurately than acrylic resins, resulting in better adaptation to the underlying tissues;
  • Are more abrasion resistant;
  • Cleanliness, due to the bacteriostatic nature of metal bases;
  • Transmission of temperature changes to the underlying tissues;
  • Can be cast in thin section, limiting their bulk without compromising on strength and rigidity.

    • Prosthetic teeth

    The material used for replacing missing tooth tissue will be influenced by the following factors:

  • The amount of prosthetic space available;
  • The material used for the denture base;
  • The presence of parafunctional habits;
  • Aesthetics, ie is the material visible on smiling and in function;
  • The position of the tooth in the arch, ie anterior or posterior;
  • The surface of the tooth to be covered, ie occlusal, labial, palatal;
  • The opposing material.

    • Materials

    Materials commonly available include:

  • Acrylic resin;
  • Chrome alloy;
  • Gold alloy;
  • Ceramic.

    • Acrylic resin

    Acrylic resin prosthetic teeth need to be provided in sufficient bulk without thin or sharp edges and can be chemically bonded to the acrylic resin base or attached to a metal base through mechanical retention or chemical bonding. An adhesive containing 4-methacryloxyethyltrimellitic anhydride (4-META) can be used to bond acrylic resin to metal-based dentures. A chemical union can make the junction more hygienic. The low abrasion resistance can make this material easy to adjust but prone to accelerated wear in patients with parafunctional habits. Acrylic resin prosthetic teeth can provide a natural appearance and are the kindest material for opposing teeth.

    Chrome alloy

    Chrome alloy prosthetic teeth can be cast in thin section and are therefore useful when space is limited. They still provide good strength and rigidity in thin section. They can be cast as part of the overall framework but their appearance will limit their use to posterior sections of mouth and as palatal backings on anterior teeth. They can, however, be difficult to adjust and also abrasive to opposing natural teeth when they lose their surface polish. Chrome alloy prosthetic teeth can be useful for covering the worn occlusal surfaces of posterior teeth with an onlay type design in patients with parafunctional habits.

    Gold alloy

    Gold alloy prosthetic teeth will cause the least abrasion to natural teeth and can be more easily adjusted. Cast gold occlusal surfaces can be attached to acrylic resin teeth and can be useful in patients who parafunction. There is a high cost involved.

    Ceramic

    Ceramic prosthetic teeth can provide excellent aesthetics but are brittle and very abrasive once they lose their surface glaze. They can also make a clicking sound in function but can be bonded to metal-based dentures through a process of tribochemical coating.

    Tooth-coloured veneering materials can be the weak link in the durability of partial and complete dentures made for patients with tooth wear. Macromechanical and micromechanical retention needs to be applied to the denture design. Retentive beads, ‘nail heads’ and struts can be combined with palatal metal backings to protect acrylic, composite or porcelain components. On occasion, these backings or onlays need to be extended up to the incisal edge or occlusal contacting surfaces (Figure 5).

    Figure 5. (a) Macromechanical and micromechanical retention needs to be applied to the partial denture design, in this case with beads and struts to retain anterior overlay veneers. (b) Further protection of acrylic components with palatal backings, in this case extended up to the incisal edge.

    Maintenance

    The cohort of patients treated with removable prostheses for worn teeth are usually older and have a number of other missing teeth. These have often been lost as a result of plaque-associated disease and so these patients are often at high risk of caries and periodontal disease. This is often compounded by diminished fine motor skills so that cleaning may still be ineffective, even if patients are motivated. Plaque accumulation will also tend to increase in the presence of removable prostheses.7 These patients must therefore be managed similarly to patients with a high caries risk.41

    It is therefore of utmost importance that patients change their behaviours in order to prolong the survival of their abutment teeth. Patients should be instructed to do the following:

  • Brush the abutment teeth including overdenture abutments with a high fluoride concentration toothpaste;
  • Use a daily fluoride mouthrinse at a different time from brushing;
  • Leave the dentures out at night and soak these in a denture-cleansing solution;
  • Apply a high fluoride concentration gel to the fit surface of the denture corresponding to the overdenture abutment in the morning.42 The patient should not eat for 30 minutes following this to maximize effectiveness;43
  • Clean the dentures after meals.

    • An occlusal splint with or without replacement teeth can be made for the patient to be worn at night to protect the abutment teeth from parafunction. If the denture design has not been robust, early failures should be expected (Figure 6).

    Figure 6. (a) Failure of an acrylic complete overdenture. (b) Failure in a partial metal framework denture. A more robust design could avoid early failure in the future.

    All of the above should be supplemented with regular recall as appropriate to review the abutment teeth, soft tissues and removable prostheses (Figure 7).

    Figure 7. (a, b) A precision retainer complete overdenture requiring considerable clinical and laboratory skill. An enthusiastic patient following a strict maintenance regimen will be required to prevent early failure.

    Maintenance care

    By definition patients treated for tooth wear are heavily restored and need more frequent review and maintenance care. Dental caries and periodontal disease can be worsened by the placement of multiple restorations or by using an overdenture. Preventive and periodontal care with a reliable recall system will help with preventing primary disease.

    Biomechanical failures should also be expected and the patient informed of this. If their teeth have been worn down or fractured, patients will exert the same forces on their restorations. If a patient is prepared to use an occlusal splint on a regular basis, adverse events can be reduced. Furthermore, well designed and executed prosthodontics can give these patients a welcome break from the restorative spiral downwards with the loss of restorations and teeth.

    Concluding remarks

    Dentists will be treating more patients with tooth wear as the population ages. There are many challenges ahead for the dental team in providing high quality dentistry for these patients. There have been many technological improvements over the years to help with providing care. As a profession we will need to continue to develop new techniques to deliver cost-effective and successful treatments for our patients.

    Key Points

  • Removable or fixed and removable management of tooth wear may be indicated in the following circumstances:
  • Severe wear;
  • Multiple missing teeth and tooth wear;
  • Soft tissue defects;
  • Long spans or distal extension;
  • Primary disease or uncertainty with the prognosis of some teeth;
  • Cost.
    •
  • If a re-organized approach is undertaken and the occlusion is to be changed, careful planning is required. Mounted study casts are required to produce a diagnostic wax-up or wax try-in. An aesthetic composite or acrylic mock try-in can be tried into the patient's mouth for approval. Digital simulations are also possible.
  • A diagnosis of compensated or non-compensated wear should be made early in treatment planning.
  • Planning follows conventional prosthodontic protocols with consideration for:
  • Saddles;
  • Support;
  • Retention;
  • Bracing and reciprocation;
  • Major connectors;
  • Indirect retention.
  • Partial or complete dentures for tooth wear patients may have one or more special components:
  • Overdenture;
  • Onlay;
  • Overlay.
  • An increase in the occlusal vertical dimension (OVD) can often be guided by:
  • The former appearance;
  • Mandibular rest position and assessment of the free-way space;
  • Former crown height;
  • OVD at the RCP;
  • Acceptance using a provisional denture for 1–6 months.
  • A diagnostic or provisional appliance should make an assessment of:
  • Appearance;
  • Lip support;
  • Occlusion;
  • Patient tolerance;
  • Durability.
  • There is not an ideal denture material to treat tooth wear. There is a compromise between aesthetic considerations and durability. Acrylic is most commonly used for denture teeth. It needs to be protected by good denture design and be used in thick section of at least 2 mm to be durable. Cobalt chrome is strong in thin section. Advances in metal primers and treatments have increased the bond between these materials. Composite, porcelain, gold alloys and flexible rubbers are alternative materials.
  • Frequent failure of denture components in tooth wear patients will be attributable to:
  • Occlusal factors;
  • Design factors;
  • Incorrect choice of material;

    • Endnotes

    The British Society for Restorative Dentistry hopes that these guidelines will act as a practical reminder of the standards that the BSRD tries to achieve. Any comments you may have will be gratefully received and should be addressed to the Honorary Secretary.