Buddle Findlay Lawyers recently reported on an interesting New Zealand Health & Disability Commissioner decision, which considered the status of treatment of a patient following an undisclosed incident during dental treatment.
A dentist had failed to tell a root canal treatment patient that a piece of instrument had broken off (a known risk) and had been left in his tooth. That fact was not included in the records. Further treatment was recommended without explaining that the reason for the treatment was, or at least included, the broken instrument. There appears to have been no disclosure despite questioning by the patient about the reason for his pain.
The Commissioner commented at  that without information about the broken instrument, the patient was not in a position to provide informed consent for the further treatment.
The question of whether the patient’s basic consent was vitiated appears not to have been discussed.