The Canadian approach would classify a dentist chair as a patient care area and require an insulated ECG or "Bonding" wire as well as all other approved bonding methods like the raceway. No spiral cable armour is acceptable as a bonding method here. Cables like core flex where the armour is continous may. Further the panel supply also must have a copper bonding conductor so no aluminum feeders unless there is an internal copper bond wire.
Where an existing occupancy changes to a medical occupancy and the existing feeders have Aluminum bond wires we have given special permission to add an external, insulated bond wire if it can be installed to follow the existing feeder and still pass the required tests for VD and Potential rise as outlined in CSA standard Z-32.
Except for some differnces in the wiring material the US and Canadian rules follow the same criteria in setting the rules. Tested Volt drop and no potential differences between grounded metal points.
