References

Mitchell D, Mitchell L. Oxford Handbook of Clinical Dentistry 6th edn.Oxford: Oxford University Press; 2014
Taji S, Seow WK. A literature review of dental erosion in children. Aust Dent J. 2010; 55:358-367
Seow WK. Developmental defects of enamel and dentine: challenges for basic science research and clinical management. Aust Dent J. 2014; 59:143-154
Gallagher S, O’Connell BC, O’Connell AC. Assessment of occlusion after placement of stainless steel crowns in children – a pilot study. J Oral Rehabil. 2014; 41:730-736
Barone A, Derchi G, Rossi A, Marconcini S, Covani U. Longitudinal clinical evaluation of bonded composite inlays: a 3-year study. Quintessence Int. 2008; 39:65-71
Manhart J, Scheibenbogen-Fuchsbrunner A, Chen HY, Hickel R. A 2-year clinical study of composite and ceramic inlays. Clin Oral Investig. 2000; 4:192-198
Yaman BC, Ozer F, Cabukusta CS, Eren MM, Koray F, Blatz MB. Microtensile bond strength to enamel affected by hypoplastic amelogenesis imperfecta. J Adhes Dent. 2014; 16:7-14
Welbury R, Duggal MS, Hosey MT Paediatric Dentistry 4th edn.(eds). Oxford: Oxford University Press; 2018

Composite onlay: an option for the restoration of hypoplastic teeth in paediatric dentistry

From Volume 46, Issue 1, January 2019 | Pages 87-89

Authors

Khadija Khaled

5th Year Student, University of Manchester and University Dental Hospital Manchester, Higher Cambridge Street, M14 6FH, UK

Articles by Khadija Khaled

Matthew Grindrod

BDS(Hons), MFDS RCPS(Glasg)

Specialty Dentist, University Dental Hospital Manchester and University Dental Hospital Manchester, Higher Cambridge Street, M14 6FH, UK

Articles by Matthew Grindrod

Siobhan M Barry

BDS, NUI(Cork), MFDS RCS(Dub), MPaedDent(Glasg), DClinDent(University of Leeds), FDS(Paed Dent), RCPS(Glasg)

Senior Lecturer/Honorary Consultant in Paediatric Dentistry, University of Manchester and University Dental Hospital Manchester, Higher Cambridge Street, M14 6FH, UK

Articles by Siobhan M Barry

Article

As enamel hypoplasia becomes increasingly more common, the general dental practitioner (GDP) may be faced with the challenges of managing hypoplastic teeth. Choosing the correct treatment option is crucial for an optimal long-term prognosis. Composite onlays may provide a straightforward and conservative treatment option for the management of hypoplastic teeth in paediatric dentistry. This article explains the simple treatment option of providing a composite onlay which can be provided without the need for any specialist equipment or training, in order to improve the long-term prognosis of these teeth.

Enamel hypoplasia is a dental defect whereby the tooth enamel is thinner, appearing pitted or grooved, as a result of a defect in enamel matrix production.1 The aetiology of enamel hypoplasia may be genetic or environmental and includes, but is not limited to, severe fluorosis, radiotherapy, chemotherapy, trauma and developmental conditions, for example amelogenesis imperfecta. Possible sequelae for this condition are an increased caries risk, dental erosion, tooth wear, sensitivity and discoloration. Therefore, patients with hypoplastic teeth require greater dental attention with regular reviews and enhanced prevention.2,3

As enamel hypoplasia becomes increasingly common, the GDP may be faced with the challenge of managing hypoplastic teeth. Choosing the correct treatment option is crucial for an optimal long-term prognosis. Many factors contribute to the decision on the best treatment option, including the location of affected teeth; extent and severity of the hypoplasia; the age and co-operativity of the patient; and the occlusion.

One particular difficulty for the GDP when treating hypoplastic teeth is bonding to the affected tooth substance. Successful bonding is essential for the success of any adhesive restorative treatment provided by the dentist. Composite restorations for hypoplastic teeth may require replacement due to bonding failure and marginal leakage around the restorations, resulting in recurrent caries. This occurs as a result of excessive masticatory forces on the weaker enamel, allowing for its gradual deterioration.3 This may render the usually straightforward treatment of providing composite restorations unfeasible. A suitable alternative is the use of indirect restorations, which provide more coverage for the tooth, thereby reducing the forces that the defective enamel must withstand. Composite onlays are an example of a simple, straightforward and conservative way of treating hypoplastic teeth and can be completed in just two appointments.

Case report

An 11-year-old boy presented with hypoplasia as a result of historical chemotherapy treatment (Figure 1). The following treatment plan was devised:

  • Intensive prevention including oral hygiene instructions, toothbrushing instructions and dietary advice;
  • Scale and polish;
  • Fissure sealants: LR6 and LL6;
  • Composite restorations: UR6 and UL6;
  • Extraction: UR4 due to very poor prognosis;
  • Indirect composite onlay: UR5;
  • Application of fluoride varnish (2.2% ppm NaF-) on remaining dentition;
  • The decision was made to treat the upper right second premolar with a composite onlay in order to protect the tooth from caries, reduce sensitivity, improve the long-term prognosis, and develop the tooth into a functioning unit.
  • Figure 1. OPG noting mixed dentition and hypoplasia UR5, UR4, UL4, UL5 and microdont LL4.

    Indirect composite onlay for the hypoplastic tooth

    First appointment

  • If necessary, place orthodontic separators through the mesial and distal contacts of the tooth in question to create space for accurate impression taking;
  • Continue with the rest of the treatment plan whilst waiting for the orthodontic separators to have an effect;
  • Remove orthodontic separators prior to taking an impression;
  • Take an impression of the arch containing the hypoplastic tooth using addition-cured silicone. Note that, in this case, no tooth preparation was required, however, in some cases, minor tooth preparation may be required, for example, in order to remove undercuts or smoothen sharp edges;
  • Take an impression of the opposing arch using addition-cured silicone or alginate;
  • Take a bite registration with addition-cured silicone;
  • Send the impressions and bite registration to the dental laboratory with appropriate laboratory prescription.
  • Second appointment

  • Check the fit of the composite onlay on the master die (Figure 2);
  • Dry the buccal mucosa and apply topical anaesthesia using a cotton wool roll for 2–3 minutes;
  • Give buccal and palatal infiltrations in order to overcome sensitivity associated with the washing and drying processes and also facilitate painless placement of the rubber dam clamp;
  • Isolate the tooth using a rubber dam for airway protection, but also to aid moisture control, which is required for optimal adhesion. Note that a split dam technique was utilized in this case (Figure 3), as it was difficult to keep the rubber dam in place due to the lack of clinical crown height;
  • Try the composite onlay on the tooth, ensuring that the fit is good and that the patient is happy with the aesthetics;
  • Cement the onlay using a dual-cure adhesive resin cement, following the manufacturer's instructions (Figure 4). In this case, Calibra (Dentsply) was used as an adhesive cement;
  • Remove excess cement with a probe and floss (Figure 5);
  • Check occlusion and excursive movements, bearing in mind that it is expected that the onlay will be in supraocclusion initially. This is not an issue as the occlusion will adapt by the Dahl effect.4 It is important to ensure that the patient is aware of this change prior to commencing the procedure in order to allow for truly informed, valid consent.
  • Figure 2. UR5 composite onlay on the master cast.
    Figure 3. Split dam technique of the hypoplastic UR5.
    Figure 4. (a, b) Conditioning, washing and drying of the tooth in preparation for cementation with an adhesive cement.
    Figure 5. Removal of excess cement from around the onlay using a probe.

    This procedure resulted in an aesthetically pleasing and functional UR5 (Figure 6) with which both the patient and parent were happy.

    Figure 6. Immediate post-operative results showing an aesthetically pleasing and functional UR5. Please note that UR4 is due for extraction due to poor prognosis.

    Discussion

    Composite onlays provide a suitable treatment option for hypoplastic teeth in the posterior region of the mouth. Although no studies have been found that investigate the success rates of composite onlays specifically, Barone et al reported a 97.4% success rate for composite inlays over a 3-year period,5 whilst Manhart et al reported a 90% success rate for composite inlays over a 2-year period.6 These studies demonstrate that composite may be a strong and durable material when used in posterior indirect restorations. However, long-term studies investigating the success of indirect composite restorations on hypoplastic teeth are still required, as it has been demonstrated that the micromorphological changes and irregularities on hypoplastic enamel surfaces affected bond strength, and therefore success rates.7 Despite the absence of evidence for success of composite onlays on hypoplastic teeth, from the authors' experience, this seems a logical method of treatment. Composite onlays not only provide the benefits of being aesthetically pleasing, but also overcome the issues of nickel allergy which can be associated with metal restorations. On the other hand, composite onlays tend to be bulkier than their metal counterparts as they must be thicker in order to withstand the forces placed on them, resulting in a greater change in occlusion.8 However, in paediatric dentistry, this is not a major issue as the occlusion will readjust itself in time. This is supported by Gallagher, O'Connell and O'Connell who found that any change in maximum intercuspation position following crown placement in children was reversed within a 4-week period.4 A summary of the pros and cons of indirect composite onlays as a treatment option for hypoplastic teeth is given in Table 1.


    Pros Cons
    Quick and effective procedure, requiring only two appointments Child must be co-operative and allow for impressions to be taken
    No tooth preparation required and therefore less destructive than other methods More expensive than alternative direct methods – laboratory fees;
    May be supra-gingival May require LA
    Suitable for patients with nickel allergy, where stainless steel crowns are not a suitable alternative Must be thicker than metal counterparts, leading to greater changes in occlusion, or the need to prepare the tooth to create the required room
    Overcomes the issues of providing a full coverage crown (large pulp size, short crown height, difficulties obtaining impressions of subgingival margins) Requires good moisture control and airway protection (ideally rubber dam) during cementation
    Covers most of the tooth surface, removing sensitivity and preventing further tooth loss The bond is critical to the success of the restoration

    Although, as with any restoration, composite onlays may require replacement, they provide an easy and effective treatment option and also improve the long-term prognosis of hypoplastic teeth. As the procedure can be undertaken in any dental practice without the need for any specialist equipment or specialist training, the GDP must consider it as a possible treatment option for hypoplastic teeth.