What is the test for standard of care in dental malpractice cases?

Where standard of care is at issue, the court must determine what is reasonably required to be done (or avoided) by the defendant in order to meet the standard of care. In a dental malpractice case, the court must determine what a reasonable dentist would have done (or not done) in order to meet the standard of care. The degree of foreseeable risk affects the determination of the standard of care: Armstrong at para 87; McArdle Estate v. Cox, 2003 ABCA 106, 327 A.R. 129.

The appellant concedes that the errors alleged all involve the trial judge’s assessment of the evidence. Accordingly, the alleged errors are errors of mixed fact and law attracting the palpable and overriding standard. A palpable error is one that is clearly wrong, unreasonable, or not reasonably supported on the evidence. An overriding error is one that would have a material impact on the outcome. Where the deferential standard of palpable and overriding error applies, therefore, an appellate court can intervene only if there is an obvious error in the trial decision that is determinative of the outcome of the case: Farsi v. Da Rocha, 2020 ONCA 92, 444 D.L.R. (4th) 197, at para 35.