Sir, a number of Americans claimed to have invented ceramic veneers, including Simonsen & Calamia (1983), Calamia (1983) and Horn (also 1983).1 In the mid-1980s, one enterprising USA company claimed that it had obtained a patent for ‘Chameleon Veneers' as well as their associated luting products. Their patent lawyers demanded royalties from UK dentists to use ‘their' technique and claimed that all dentists had to use a ‘Chameleon certified' laboratory for the manufacture of any ceramic veneers.

The truth, as proven in a BDJ letter2 and article,3 is that the development of etching of ceramics for uses in dentistry goes back to the 1960s and was based on the work of Professor William Mc Culloch, a Scotsman, who was head of Prosthetic Dentistry in University College, Cork, Ireland. ‘Bill' had completed his MSc project on etching ceramics in Manchester from 1966-1967 and it is published there (Dental Ceramics MSc Thesis Manchester 1967).

He applied for various patents in the UK and USA (Mc Culloch W.T. Great Britain Patent Application No10779 March [1967]; Mc Culloch US Patent Application 815225 [1967]).

His 1968 BDJ article was illustrated by photographs of a set of anterior ceramic veneers, taken by the Department of Medical Illustration of the Manchester Royal Infirmary and dated 1 March 1967.3 In his 1987 ‘letter to the editor of the BDJ' entitled ‘USA patent problems', Bill Mc Culloch rejected outright the claims of validity of USA patents for ceramic veneers (mainly because they were not original) and urged dentists to resist any company's demands for royalties for their use.2

He wrote: ‘I also claim that the fabrication of pre-formed or custom ceramic was described, illustrated and implicit in the publication in the article in the BDJ in 1968 and also in my MSc thesis in 1967. For my part, therefore, I am quite willing that any of my colleagues should use the procedures on castable ceramics and on anterior veneers based on the research which I performed in Manchester University from 1966-1968 without having to consider royalties. If any of my other colleagues, or their legal advisors, choose to challenge my inventions as not being the original, I invite them to prove prior claims antedating mine in 1967. I am quite convinced they cannot, and the onus is on them to prove the originality of their patents, especially if they wish to impose any industrial restrictions.'

I assured Bill that I would help to dispel some myths about various Americans developing veneers and, hopefully, ensure that credit for the original etching for conservative ceramic veneers was attributed correctly to him … hence this current letter.