Tomes invented a set of anatomically correct forceps for tooth extraction, thereby elevating this device, which had been previously neglected, to dentistry’s most important extraction instrument. This book was revised and expanded from lectures originally published in the Medical Gazette at irregular intervals between 1845 and 1847.
Tomes persuaded the Royal College of Surgeons to grant a Licence, was a co-founder of the Odontological Society in 1856, and founded the (Royal) Dental Hospital in 1858. He played a leading part in the movement which led to the passing of the Dentists Act, 1878.

Tomes described and drew the protoplasmic processes from the odontoblasts, which are known as “Tomes’s fibrils”. These had been previously seen by Johannes Müller and others.