Unique academic record
On Harold Mattingley's return to Melbourne to further his studies after 12 years' invaluable practical experience on the Western Australian goldfields, the Melbourne University dental faculty recommended that he proceed to the degrees of Bachelor of Dental Science and of Doctor of Dental Science simultaneously. In an outstanding academic performance, he was admitted to both degrees on April 9, 1914.

Battle for standards
The spread of dental companies touting cheap services had polarised the profession into "ethical" and "advertising" factions, while the profession had split heatedly over dentists who were recorded but not registered by the Dental Board because they did not hold dental diplomas or degrees. "Quickie" doctorates gained in America also were an issue. A move to have Harold Mattingley elected to the Dental Board of Victoria to defend the position for trained dentists was unsuccessful. However, he was elected Vice President of the Dental Association in 1920 and President of the prestigious Melbourne University Association, forerunner of the Graduate Union.

In 1935 Harold Mattingley's work attracted the attention of eminent London dental scientist Dr. Wilfred (later Sir Wilfred) Fish, a member of the United Kingdom Dental Board, an executive member of the Royal Society of Medicine and Winston Churchhill's professional consultant. Dr Fish wrote, "Dear Mattingley - It is delightful of you to let me have all this material (on the dental health of Aborigines). I shall be talking on my Australian experiences and shall incorporate your findings. Your record is just exactly what I want" and later , "I hasten to tell you what a profound interest the men in London have shown in your material".