Does anyone know how dental schools view clinical volunteering v. nonclinical volunteering. Is the former an absolute necessity?
It depends what you mean by "clinical volunteering". Do you mean shadowing or assisting a dentist? Or do you mean other clinical volunteering (hospital, etc.).
If you mean the former, then yes. Most dental schools require a 100 hours of dental shadowing (observing and watching the dentist treat patients while asking questions, seeing how a dental office is run, respectfully interacting with the patients and staff, etc.) and this is as "clinical" as you need to get.
If you mean the latter, then no. You don't necessarily need to add other clinical volunteering on top of shadowing. Clinical volunteering is not a necessity nor is it necessarily favored over non-clinical volunteering by admission committees.
Dental schools want to see that you're diverse. Clinical volunteering is great but if you do non-clinical volunteering such as packaging food at a homeless shelter, helping the poor, marshaling a fundraising marathon, etc. because you have a passion for giving back to the community and whatnot, that is equally great.