A native of mid-state Wisconsin, Dr. Ingersoll attended Andrews University in Michigan as an undergraduate before enrolling at Loma Linda School of Dentistry. After earning his D.D.S. degree, and completing a Restorative Dentistry residency, he taught full time in the Restorative Department at LLU. 

Dr. Ingersoll continued his studies at LLU, earning an addional two year Masters Degree in the specialty of Endodontics. The Chariman of the Department of Endodontics, Dr. Ronald Buell, subsequently invited Dr. Ingersoll to join his private practice in Santa Ana.

Dr. Ingersoll remains an Associate Professor of Endodontics at the LLU School of Dentistry. For the last 15 years, he has also served as a consultant to the California State Board of Dental Examiners.