Root canal likely

...Ms B insists on a composite filling but moisture control is difficult and she keeps closing her mouth...

  • Date: 28 June 2017


Ms B attends as a new patient at a local dental surgery complaining of sensitivity in a number of teeth. A dental associate – Mr W – arranges bitewing radiographs and these show gross distal caries at LR6 and caries in a number of other teeth. He advises that LR6 is of most concern and recommends treatment by an amalgam filling, given the size and depth of the caries. Ms B insists on a composite filling as it looks more “natural”. Mr W agrees but records his discussion with the patient regarding the pros and cons of composite versus amalgam filling in this particular case.


Mr W places an extensive composite filling at LR6 but moisture control is difficult as there is an excess of saliva and gingival bleeding. Ms B is also phobic and “fidgety” and keeps closing her mouth. Mr W informs the patient that given the extent of the cavity and difficulty of the procedure, root canal treatment (RCT) may be necessary in the future if the tooth does not “settle”.


Ms B attends a different dentist complaining of pain in LR6. The dentist also notes untreated caries in three other teeth. A radiograph reveals decay under the filling at LR6 and the dentist undertakes the first stage of RCT and the tooth is dressed with Ledermix.


The patient returns to the new dentist and undergoes root canal treatment on LR6 and another appointment is scheduled to carry out further restorations on the other untreated caries.


A LETTER of claim for clinical negligence is received by Mr W from solicitors acting on behalf of Ms B. It alleges incomplete removal of caries at LR6 and also inadequate moisture control resulting in a reduced bond in the composite filling causing recurrent caries and chronic pain with later irreversible pulpitis necessitating root canal treatment.

Ms B claims damages amounting to the cost of the RCT in addition to time off work due to chronic pain.

MDDUS obtains copies of the patient notes and all relevant radiographs and sets out a letter of response based on a detailed case report. It is argued that Mr W carried out the initial restoration on LR6 in very challenging circumstances and to the best of his ability – as would any reasonable and competent general dental practitioner.

Moisture control was difficult given the problems of a phobic patient and restricted access. Mr W used high aspiration, cheek retraction and cotton wool to absorb moisture the best he could. To the extent there may have been a reduced bond this was more likely to do with the extent of the cavity and use of a composite filling rather than amalgam as was advised by the dentist. Amalgam may not be as aesthetically pleasing but it will restore a tooth even in the presence of moisture whereas with composite materials moisture control is essential as bonding is actively to the tooth substance.

In regard to causation MDDUS argues that the root canal treatment could not be the result of any act or omission by Mr W. The patient presented with extensive caries in LR6 and rejected the dentist’s advice on an amalgam filling and – on the balance of probabilities – would have thus required root canal treatment at LR6 in any event.

It is clear that not all the decay was removed in Mr W’s restoration of LR6 but it would not be unreasonable to leave some decay on the base of a cavity and appropriately seal it and allow the tooth to heal.

MDDUS sends the letter of response and receives notification that the case is being dropped.

Key points

  • Keep records of discussions with patients in support of shared decision making and consent.
  • Advise patients of likely prognosis even with adequate treatment.
  • Consider being more proactive in advising patients on the “best” treatment option.

This page was correct at the time of publication. Any guidance is intended as general guidance for members only. If you are a member and need specific advice relating to your own circumstances, please contact one of our advisers.

Read more from this issue of Insight Primary

SoundBite is published twice a year and distributed to MDDUS members in their final year of dental school and to those undertaking one or two years of postgraduate training throughout the UK. It provides a mix of articles on risk, dento-legal and regulatory matters as well as general features and profiles of interest to trainee dentists.
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