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Patient Sues Dentist for Nerve Pain After RCT and Patient Loses!

By May 3, 2022May 14th, 2022Michael's Operatory

Another legal victory for dentists generally and a dentist in BC specifically!

In my previous blog, I wrote about how a patient in Ontario took legal action against a dentist in Ontario for allegedly discriminating against the patient’s daughter (it didn’t happen). The patient, thankfully, lost that case.

Now, we have another case. This one is out in British Columbia, mind you. And this is a very important case for all dentists because it deals with INFORMED CONSENT and BREACH OF CONTRACT in relation to an RCT.

The case is Parhar v. Weaver, 2021 BCSC 123. Below I’ll go over the case and the BC Court of Appeal decision (which re-affirmed the case in favour of the Dentist).

The Facts

The patient (Mr. Karunbir Parhar) experienced debilitating pain – which lasted years – after an RCT on his 46 (i.e. lower right quadrant, first molar). The procedure was performed by the defendant Dr. Brennan Weaver in Terrace, British Columbia on September 24, 2014. The patient believed the paint was associated with the RCT. Interestingly, the patient didn’t allege that the RCT was done negligently; rather, the patient alleged that the dentist didn’t tell him about “a material risk of chronic nerve pain” and thereby failed to obtain informed consent before doing the RCT.

The trial judge accepted the following facts based on the evidence:

  1. Before the RCT, Mr. Parhar’s overall dental health was poor.
  2. When Mr. Parhar initially met Dr. Weaver in 2012, he wasn’t overly fearful of treatments or concerned about the pain.
  3. Dr. Weaver’s 2012 treatment plan in 2012 included general discussions about RCTs, extractions and replacements. Dr. Weaver extracted tooth 28 (molar in the upper left quadrant), and there was no issue. Also, Dr. Weaver did an RCT on 24 (upper left first pre molar). Although Dr. Weaver did not obtain consent in writing, he explained the procedure to Mr. Parhar and told him about the likelihood of post-operative pain. Mr. Parhar had no questions and consented to the procedure. The RCT was done without incident and had no adverse consequences.


Now, with respect to tooth 46, the judge found the following facts:

  1. It became problematic in 2014. Dr. Weaver placed a filling on it and informed Mr. Parhar of the risk that this tooth could further deteriorate to the point where it would require either a root canal or extraction.
  2. The pain in tooth 46 flared up again in September 2014. Mr. Parhar went to see Dr. Weaver about it on 24 September 2014, a few weeks after the pain had begun. Dr. Weaver said the tooth was abscessed and recommended a root canal. The root canal procedure did not take place on 24 September 2014. Mr. Parhar was given a prescription for antibiotics and was told to make a further appointment if he wanted to proceed.
  3. During the 24 September 2014 appointment, Dr. Weaver had a discussion with Mr. Parhar about the treatment options for tooth 46. Dr. Weaver emphasized the importance of saving tooth 46 for chewing because it was the only remaining molar in the lower right quadrant of Mr. Parhar’s mouth. This was the basis for Dr. Weaver’s recommendation for a root canal.
  4. In between the consultation with Dr. Weaver on September 24, 2014, and the root canal procedure on 29 September 2014, Mr. Parhar experienced continuing pain in tooth 46. The pain was serious enough to cause Mr. Parhar to visit the hospital on 26 September 2014, where the doctor gave him anti-inflammatory pain medication pending his next dental appointment.
  5. During the appointment on 29 September 2014, prior to commencing the root canal on tooth 46, he described the procedure to Mr. Parhar. This included a description of what Mr. Parhar could expect in the procedure, what to do if he experienced any pain during the procedure, and the probability of post-operative pain that could be expected to subside within a week.
  6. Dr. Weaver did not specifically advise Mr. Parhar of the risk of ongoing or chronic nerve-related pain, because Dr. Weaver was not aware of such a risk. One of the key legal issues addressed below is whether the risk of continuing or chronic nerve-related pain is properly characterized as a material, special, or unusual risk associated with a root canal.
  7. If Mr. Parhar believed he had been informed about a risk of chronic nerve-related pain, he would have opted for extraction rather than a root canal.
  8. The RCT on tooth 46 was uneventful and involved no apparent complications. Dr. Weaver’s dental staff was trained to watch the patient for signs of discomfort during the procedure, and none were observed or noted.
  9. After the RCT and even up to the trial, Mr. Parhar experienced ongoing and sometimes debilitating chronic nerve pain.
  10. The pain was initially in the area of tooth 46, although more or less right away, it moved around or shifted to different parts of Mr. Parhar’s mouth. The pain has continued to alternate between the right side and left side of his mouth. On average or in the aggregate, the pain is on the right side about 60% of the time and on the left side about 40% of the time.
  11.  The pain has been so bad that it has significantly affected Mr. Parhar’s lifestyle and activities of daily living. Mr. Parhar was bedridden but unable to sleep properly for at least three months. He went to work for about a week but, after that, was unable to concentrate for a full shift. He also had difficulty eating.
  12. After the root canal, Mr. Parhar saw Dr. Weaver and a number of other dentists and doctors. None of them were able to diagnose or resolve the problem.
  13. Eventually, Mr. Parhar was prescribed medication that has helped him sleep. With the assistance of this medication, Ms. Parhar is now able to manage his sleep and go to work. However, the pain in his mouth still affects him in a number of ways. He has difficulty eating. He is also less active, less outgoing, and does not socialize as much as he did.
  14. The pain is present most of the time, though not always. There are some days when he is pain-free. Mr. Parhar estimates that he is in pain about 90% of the time. It also varies in intensity. At its worst, it is debilitating.

Was Dr. Weaver Negligent?

To prove negligence for failing to disclose the risk of chronic, debilitating nerve pain for an RCT, Mr. Parhar had to satisfy a 3-part test:

  1. Prove that Dr. Weaver failed to inform him about the nature of the medical procedure and any material, special, or unusual risks that it entails.
  2. Prove that a reasonable person standing in his shoes, properly informed of the nature of the procedure and the relevant risks, would not have consented to the procedure.
  3. Prove that the particular risk or risks not explained to him were, in fact, the cause of the injuries for which he claims damages.

Part 1: Did Dr. Weaver Fail to Inform?

Dr. Weaver was obliged to inform Mr. Parhar about the nature and gravity of the proposed root canal, along with any material, special or unusual risks associated with this procedure. He was also obliged to explain to Mr. Parhar the treatment options for tooth 46.

The Court found that he had done so: Dr. Weaver discussed the treatment options for tooth 46, recommended a root canal given the anatomical importance of that particular tooth, and gave a description of the root canal and the consequences. This included the likelihood of post-operative pain that is normally expected to resolve within one week. The Court accepted that Dr. Weaver had obtained “adequate verbal informed consent” to perform a root canal on tooth 46.

The next issue is whether Dr. Weaver failed to inform Mr. Parhar of the risk of chronic nerve pain. After reviewing all the expert evidence jurisprudence, the Court found that Mr. Parhar had failed to prove that “non-ondontic, nerve-related chronic pain is a material, special, or unusual risk associated with a root canal procedure. The evidence establishes that there is some risk, but the risk of moderate to severe nerve-related pain is extremely low to the point that it cannot be meaningfully quantified.”

The Court went on to write that it could not conclude that the risk was sufficiently material to require Dr. Weaver to advise Mr. Parhar of it as a prerequisite to obtaining informed consent for the root canal procedure on tooth 46. Importantly, the Court held that this was a case-specific conclusion and turned on the evidence presented at that particular trial.

WOW. Just WOW. So in this particular case, Dr. Weaver did not have to explain the risk of debilitating and chronic nerve pain as part of getting informed consent because the risk of such pain was extremely low to the point that it cannot be meaningfully quantified.

As such, the Court dismissed Mr. Parhar’s negligence claim on the basis that he had not proven that Dr. Weaver failed to properly disclose a material, special, or unusual risk for the purposes of obtaining informed consent.

Part 2: Would a Reasonable Person in Mr. Parhar’s circumstances have consented to the RCT?

Given all the facts, the Court held that Mr. Parhar failed to prove that a reasonable person in his circumstances would NOT have consented to the RCT. Per the Court:

I start from the premise that Mr. Parhar was in severe pain at the time that he sought out treatment for tooth 46 in late September 2014, so doing nothing was not a realistic option. He acknowledged this in his testimony. As for the choice between a root canal and an extraction, a reasonable person in Mr. Parhar’s shoes, even one principally focused on stopping the pain from tooth 46, and appreciating that substantially the same risk of chronic nerve-related pain would apply to either extraction or a root canal, would have deferred to Dr. Weaver’s recommendation. This is particularly so considering the aesthetic and anatomical benefits of saving tooth 46, as opposed to extracting it. I therefore find on a balance of probabilities that a reasonable person in Mr. Parhar’s circumstances, fully informed of the relevant risks, would have opted for a root canal.

Part 3: Did the Particular Risk or Risks Not Explained to Mr. Parhar In Fact Cause His Injuries?

Here the Court reviewed all the expert testimony and concluded that there wasn’t enough evidence to prove that the risks caused the injuries complained of.

The Court reasoned that the pain Mr. Parhar experiences on the right side of his face was indistinguishable from the pain he experiences on the left side of his face. But the overwhelming weight of the expert opinion evidence is that nerve-related pain from an endodontic procedure performed on the right side of the mouth would not produce pain on the left side of the mouth. This caused the Court to question whether any of the pain suffered by Mr. Parhar in the wake of the root canal on tooth 46 was caused by the root canal procedure. Based on this concern alone, the Court was “not satisfied on a balance of probabilities that a risk of nerve-related chronic pain associated with a root canal procedure actually materialized to cause the symptoms Mr. Parhar has experienced and continues to experience”.


Even though the trial judge found that there WAS NO NEGLIGENCE, they went on to say that IF there WAS NEGLIGENCE, the damages would have been $93k in non-pecuniary damages plus 10k in damages for past loss of earnings.


Mr. Parhar also argued that Dr. Weaver had committed breach of contract. Specifically, Mr. Parhar argued that:

  1. There was a contract for services for Dr. Weaver to perform an RCT on tooth 46 in exchange for a fee;
  2. An implied term of the contract was that Dr. Weaver would be expected to perform the root canal with “reasonable care and skill”; and
  3. An implied term of the contract was that Dr. Weaver would have advised Mr. Parhar of a material risk associated with the root canal procedure.

The Court, however, rejected that there had been a breach of contract. To begin, for over three decades, Canadian courts have shown a strong inclination to determine cases of alleged failure to obtain informed consent for a medical procedure under the law of negligence (which the trial judge already dismissed for the reasons given above). More importantly, Mr. Parhar could not even prove that there EXISTED an implied term of a contract where Dr. Weaver had to disclose a material, special, or unusual risk for the purposes of obtaining informed consent for the RCT. Per the trial judge: “This finding is fatal to the breach of contract claim as formulated by the plaintiff.”

Mr. Parhar was ordered to pay costs at trial.

BC Court of Appeal

Despite losing the case, Mr. Parhar appealed the decision to the BC Court of Appeal (Parhar v. Weaver, 2022 BCCA 134 (CanLII).

First, Mr. Parhar alleged that the risk of chronic nerve pain WAS indeed a risk that required disclosure and that the trial judge had gotten it all wrong. But the Court of Appeal disagreed. The Court of Appeal held that the trial judge had NOT made a palpable and overriding error in taking into account the evidence. The trial judge had found, based on the evidence, that “the incidence of moderate to severe chronic nerve-related pain following a root canal is extremely low, to the point that the risk cannot be meaningfully quantified.” Per the Court of Appeal: “This finding was open to the judge on the evidence”.

Second, Mr. Parhar alleged that a claim in contract law was available for Dr. Weaver’s failure to inform a patient of a material risk of chronic never pain. BUT once again, the Court of Appeal disagreed: “there is no reviewable error in the judge’s conclusion that there was not a risk of chronic nerve pain that legally required disclosure, it is not necessary to further discuss this issue.”

Case dismissed at the Court of Appeal level.

Bottom Line

This BC Case sets a very high standard for other Canadian Courts faced with (1) negligence claims by patients against dentists for RCTs and (2) breach of contract cases for RCTs (on the basis that they should be decided in negligence).

The Content of this post is provided for informational purposes only. It is not intended to be legal, financial, tax, or other professional advice of any kind. You are advised to contact DMC (or other counsel) to seek specific legal advice concerning your individual situation.