Fillings aren’t forever – should they be repaired or replaced?

The risk of failed fillings

A failed filling could have a variety of causes. From a blow to the mouth, to chewing on a solid object, or even grinding the teeth, a filling can fracture or come loose. Even naturally over time, the bond between the filling and tooth will weaken, potentially exposing vulnerable gaps within the tooth’s structure.

If a patient doesn’t visually identify an issue, their symptoms could manifest as pain or increased sensitivity within their teeth. A cracked filling could also catch tissue from the gingiva, cheeks or tongue, and become irritating.

The primary concern with a failed filling is an accelerated potential of infection. The uncovered space within the tooth is immediately susceptible to bacteria which, if left untreated, can resume the decaying process that the restoration initially prevented. Treating a failed filling quickly after issues first arise is important (within days is optimal), but it doesn’t always mean an entire replacement is needed.

Replace vs. repair

A dentist’s decision to replace or repair a filling will need to be judged by each unique case. The presence of secondary caries is the primary reason for a replacement of a restoration, second being a fracture.[ii] In some cases of damage and decay, a replacement is the only appropriate option for the patient. The choice of treatment shouldn’t be immediately prescriptive, though, and instead a clinician should consider if repairing a restoration can be as effective, whilst benefitting the patient experience.

Repeatedly replacing an entire filling often requires removing an increasing amount of dental tissue, in turn reducing the lifespan of the remaining tooth structure.[iii] When repairing a filling, a dentist can typically only remove the compromised parts of the previous restoration and any present decay, before providing new material to reseal the defective area.

Repairing restorations can preserve tooth structure and reduce the risk of treatment related complications.[iv] When a dentist and patient choose to repair a restoration, they increase the lifespan of treatment and the underlying tooth.[v] Repair is also usually preferable for practitioners that adopt minimal intervention techniques for their patients.

Approaching a failed filling with intention to repair as opposed to remove and replace it entirely is often less time-consuming, and more cost-efficient – for the practice and patient.[vi] Studies have also found that patient anxiety is lower when faced with a repair in comparison to a replacement of a previous treatment.[vii] This could be attributed to a shortened treatment time, and the potential of a less invasive procedure.

Tackling the task

The materials that dentists use in each treatment are also notably different. Composite or glass ionomer cements are often used in repair, as opposed to amalgam in complete replacements[viii] (which is particularly common within NHS treatments).

Amalgam has a complicated standing within modern dentistry. Whilst being durable and cheap (in comparison to other materials), its use in dentistry is planned to be phased out by 2030, due to environmental concerns for its mercury content.[ix] Despite general agreement deeming amalgam safe for patients, many individuals are seeking alternatives to minimise the risks the mercury content could cause their body.[x] Its solid silver appearance is also generally unfavourable aesthetically, which is quickly becoming a high priority for patients.[xi]

Composites are often preferable due to their natural look, making them appropriate for an aesthetically pleasing result. They will bond firmly with existing fillings (especially those built up of composites) and teeth, which makes them suitable for repairs. Optimal retention between composite and a pre-existing amalgam filling is achieved by creating dovetails or undercuts in the old restoration.[xii]

Glass ionomer cements also produce excellent aesthetic results whilst providing firm adhesive properties to enamel and dentine.[xiii] They have the added benefit of releasing fluoride over time.[xiv] Glass ionomers therefore not only repair failed fillings, but remineralise the surrounding enamel to prevent future decay.

Repairing a patient’s filling where possible can benefit all individuals involved, but it’s important to have the appropriate material for the task. Diamond Carve Glass Ionomer Cement from Kemdent provides dentists with a clinically proven restorative material that performs highly aesthetic procedures quickly and effectively. Its use in amalgam repairs can minimise a patient’s chair time with application in one increment, achievable without dimensional change and consequential cracking, as sometimes seen when using composites.

Failed fillings can’t be cared for with one universal treatment, but repairing where possible could be the key to longer lasting treatment, and a happier patient leaving the chair.

For more information about the leading solutions available from Kemdent, please visit www.kemdent.co.uk or call 01793 770 256

[i] Dentaly.org, Interesting Facts about Teeth and UK Dental Statistics. Link: https://www.dentaly.org/en/dental-facts-statistics/ [Accessed Apr 2023]

[ii] Askar, H., Krois, J., Göstemeyer, G., Bottenberg, P., Zero, D., Banerjee, A., & Schwendicke, F. (2020). Secondary caries: what is it, and how it can be controlled, detected, and managed?. Clinical oral investigations, 24, 1869-1876.

[iii] Askar, H., Krois, J., Göstemeyer, G., Bottenberg, P., Zero, D., Banerjee, A., & Schwendicke, F. (2020). Secondary caries: what is it, and how it can be controlled, detected, and managed?. Clinical oral investigations, 24, 1869-1876.

[iv] Askar, H., Krois, J., Göstemeyer, G., Bottenberg, P., Zero, D., Banerjee, A., & Schwendicke, F. (2020). Secondary caries: what is it, and how it can be controlled, detected, and managed?. Clinical oral investigations, 24, 1869-1876.

[v] Kanzow, P., Wiegand, A., Goestemeyer, G., & Schwendicke, F. (2018). Understanding the management and teaching of dental restoration repair: systematic review and meta-analysis of surveys. Journal of dentistry, 69, 1-21.

[vi] Blum, I. R., Lynch, C. D., & Wilson, N. H. (2014). Factors influencing repair of dental restorations with resin composite. Clinical, cosmetic and investigational dentistry, 81-87.

^[vii] Javidi, H., Tickle, M., & Aggarwal, V. R. (2015). Repair vs replacement of failed restorations in general dental practice: factors influencing treatment choices and outcomes. British Dental Journal, 218(1), E2-E2.

[viii] Javidi, H., Tickle, M., & Aggarwal, V. R. (2015). Repair vs replacement of failed restorations in general dental practice: factors influencing treatment choices and outcomes. British Dental Journal, 218(1), E2-E2.

[ix] British Dental Association, Dental Amalgam. Link: https://bda.org/amalgam [Accessed Apr 2023]

[x] Colson, D. G. (2012). A safe protocol for amalgam removal. Journal of environmental and public health, 2012.

[xi] Shenoy, A. (2008). Is it the end of the road for dental amalgam? A critical review. Journal of conservative dentistry: JCD, 11(3), 99.

[xii] Staxrud F, Mulic A., (2018). Bonding of Composite and Glass-Ionomer to Amalgam. J Dent Oral Biol, 3(6), 1145.

[xiii] Staxrud F, Mulic A., (2018). Bonding of Composite and Glass-Ionomer to Amalgam. J Dent Oral Biol, 3(6), 1145.

[xiv] Sidhu, S. K., & Nicholson, J. W. (2016). A review of glass-ionomer cements for clinical dentistry. Journal of functional biomaterials, 7(3), 16.