William Dall: A Dental Research Pioneer by Michael A. Gow BDS (Gla) MFDS RCPS (Gla) MSc Hyp (Lon) PGCert (Edin), Editor, DentaltownUK magazi

I'd like to introduce you to one of my 'dental heroes'—a pioneer by the name of William Dall LDS, RFPS (Glas). He was born in Fife in 1855 and passed his exams to gain his LDS and become a qualified dentist in 1881, despite there being no record of him ever attending any official training at a dental school! I love the thought of Dall, just turning up to sit his dental exam, having not attended a single formal lecture. His training would likely have been in the form of apprenticeships and self-learning.

I have been using digital techniques to manufacture ceramic inlays for around ten years now, and have a keen interest in dental history (I sit on the Executive of The History of Dentistry Research Group- see www.historyofdentistry.group).

I am very proud that my great grandfather's adopted cousin Edward Tull-Warnock (the first black UK qualified dentist) was awarded second prize in the Dall Medal in 1910. Dall sponsored student medals in Scottish Dental schools for 'expertise in laboratory and porcelain techniques'. It was while researching Edward's life for an article that I was writing that I first encountered the name William Dall and I was interested to learn more about him.

Dall gave a lecture to the West of Scotland branch of the British Dental Association on the 28th February 1889. The topic was 'Porcelain Fillings, Plain and Gum Coloured'.¹ He confessed in this lecture that he started trying to use porcelain as a filling material in 1886 but abandoned it because of the unsatisfactory results he obtained using fused porcelain fillings or inlays supplied by the dental depots. "These were neither of the proper shape nor delicate enough in shade of colour". His patients however disagreed and continued to request more work of this nature. Dall stated that "People are becoming more artistic" and, "we are more and more asked to keep the gold out of sight." He became the foremost exponent of ground porcelain inlays of his day, developing and demonstrating techniques which facilitated and improved every aspect of porcelain inlay work and recommended its use for practically every restorative procedure. He said, "Some dentists use porcelain only in exceptional circumstances; with me it is the exception where it cannot be used."¹

Dall started work on his book Ground Porcelain Inlays2 in the 1890s and had nearly completed it by 1911. Due to 'unforeseen circumstances' and then the outbreak of war, however, it remained unpublished until on his deathbed he proclaimed that this was his deepest regret in life. His dying wish was for it to be completed, and so it came to pass, that just a few months after his death in 1932, through great endeavour from his wife, the book was finally published. Mrs Lilian Lindsay (first female UK qualified dentist and first female president of the BDA) and Sir Frank Colyer assisted Mrs Dall to ensure the book made it to print. I own a copy of the book that was presented by Mrs Dall to the school library at The Royal Dental Hospital of London.

In his preface, Dall states, 'This book is the outcome of over twenty years' experience of a class of work which from the outset has had a strong fascination for me. In the search for something which would take the place of the unsightly appearance of gold, and be more durable in its nature than white filling material, I commenced in 1887 to experiment with little round inlays ground from any porcelain tooth which was conveniently at hand.'2

The book is a fascinating read, with explanations as to how to restore a variety of cavity designs with porcelain. The illustrations in the book are outstanding. It is full of surprises, such as his description of using rubber dam. I have to admit that I am surprised that they used it 100 years ago and would have guessed that its introduction would have been a mid-20th-century occurrence.

With the advancement of digital dental technology, I often wonder what Dall would make of the dental world of today. He pioneered a variety of techniques in his work with porcelain. His techniques can be best described as HAD/HAM (H="hand") as opposed to CAD/CAM, yet some of his workflow processes are surprisingly contemporary and familiar.

One direct technique involved measuring the finished cavity's length and breadth with calipers and then cutting a slab of porcelain to the desired dimensions.

He describes the indirect version of this technique, stating that following an impression, a cast can be made of the tooth and prepared cavity. Then an assistant could, using the required shade, 'fit the slab of porcelain to the mould by cutting and trimming it with a diamond disc'. Both these workflows are still used today in porcelain inlay production, but the processes usually involve computers rather than hands to make them! Dall would certainly recognise and appreciate the modern processes.

He describes another technique whereby he designed and patented a series of dental burs which would be used to finish a cavity preparation. Each bur was numbered, and would have a corresponding, prefabricated inlay made to that shape (in a variety of shades).

He would, when required, plug a cavity base with cohesive gold foil or amalgam prior to inlay insertion to get optimal fit.

Dall designed and patented many things including porcelain stains, furnace designs, dental burs, etc. He was remarkably successful in obtaining commercial support- eg he worked with Claudius Ash & Sons Ltd (with porcelain inlay kits and dental instruments bearing Dall's name).

Dall travelled to South Africa and Brazil to source the most suitable diamond for use in his dental burs.

He was also a collector of dental artefacts during his travels. If you have ever visited the BDA museum, you will likely have encountered some of his collection. His technique was to engage with remote communities, and request to observe their 'dentist' at work. He would record the techniques employed and often purchase the dentist's tools. I love the language he uses in his descriptions of these encounters.

'While at Mount Abu, in British India, I espied in one of my perambulations a native with circular gold inlays in his upper central incisors, which were beautifully inlaid. When I asked him who had done them he said: "Sahib, myself", at which I was a little puzzled. Further inquiries elicited the fact that he and his father were jewellers'.2 Dall goes on to describe paying the jeweller to perform the procedure on a patient for him to observe—promising to pay him several rupees! He also describes a visit to Java, where he discovered that locals disliked the natural appearance of the 'upper 6 front teeth' as they look too much like those of an animal! Their solution was to shorten them by filing. 'Knowing that the idea was prevalent amongst them, I succeeded in coming in touch with a native dentist, a most primitive representative of the profession. For a small fee he was very pleased to bring a patient, a Javanese boy of twelve years of age, and to perform the operation before me on the verandah of my room at the hotel. He willingly handed over his full equipment to me when finished and I am sure dental instruments more crude have never been seen'. 2

Dall's dental travels interest me greatly. I have also visited dentists in their practices and schools all over the world in a bid to learn more. There is nothing quite like watching a dentist in a foreign land to see the similarities and differences in how certain techniques are carried out and to learn from the experience. In fact, I still use certain tips I picked up from Dr Garry Lunn when I visited his practice in Vancouver nearly 20 years ago. (Please see Garry's awesome article in our lifestyle section this month!)

This philosophy of utilising this wider sphere of learning in fact is part of the inspiration to create DentaltownUK and deliver a unique mix of international and, in particular, transatlantic cases and articles in an engaging and enjoyable new way to UK dentists and to encourage them to join the largest dental discussion forum in the world at dentaltown.com.

Dall worked at a few locations in Scotland, but for a few years (up until 1893), he worked and resided at 4, Newton Terrace, Glasgow. Dall's life and work had already fascinated me—and so you can imagine my total surprise to discover that address. My dental practice (The Berkeley Clinic) is at 5 Newton Terrace, Glasgow—literally next door. We share an interest in ceramic dentistry, travelling, lecturing and learning and are separated by around 124mm of brickwork and 124 years!

Dall states 'To accomplish good work in this speciality of inlaying teeth all the instruments employed must be of the best'. I believe that if Dall 'perambulated' the exhibition halls of any dental show today, he would marvel in what instruments he 'espied'. The advancements that have been made in the 'instruments employed' in dentistry have been huge, however I believe that he would recognise the principles and workflow.

The late Henry Noble concluded that "William Dall was much more than a dental technician and operator. He was an innovator and a dedicated teacher who felt compelled to communicate to others the techniques which he found to be of advantage in his work. Modern equipment and materials have superseded his methods but the painstaking attention to detail which he advocated continues to inspire the best results in laboratory and chair-side techniques."2