At the time of his death, he was Emeritus Professor of Oral Health Sciences, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London and Honorary Professor of Dental Research, Menzie’s Health Institute Queensland, Griffith University, Australia.

Newell joined King’s College London (formerly KCSMD) in 1993 having served London Hospital Medical College as Professor of Oral Pathology, as Hon. Director, Medical Research Council Dental Research Unit. London and Nuffield Research Professor of Dental Sciences, at the Royal College of Surgeons England; At King’s Dental Institute in addition to his duties as Professor of Oral Medicine & Pathology he was the Director, Research & Postgrad Education, 1984-2003. Following his retirement from King’s in 2005 Newell took up the position of the Foundation Dean/Head of School of Dentistry & Oral Health, Griffith University, Australia; and Professor of Dental Research, Griffith University, Australia; From 2009 and till recently he served as a Senior Fellow, Menzies Health Institute Queensland; Director of Population Oral Health; Senior Member of Infectious Diseases and Immunology Group; Cancer Research Centre.

Newell was a Fellow in Dental Surgery, Royal College of Surgeons of Eng. (FDSRCS) 1966, Fellow of the Royal Australasian College of Dental Surgeons (FRACDS) 1967, Doctor of Philosophy, (PhD), University of Bristol, UK 1975, Member of the Royal College of Pathologists, UK, (MRC Path), 1982 Fellow of the Royal College of Pathologists, (FRCPath) 1996, Fellow of the Faculty of Oral Pathology of the Royal College of Pathologists Australasia 1998, Fellow of the Academy of Medicine (FMedSci, UK).

Newell’s Honours include the International Association for Dental Research Distinguished Scientist Award in Oral Medicine and Pathology, 2005; Distinguished Scientist Award for International Oral Health from the International Association for Dental Research, 2017 ; the John Tomes Medal of the British Dental Association for Outstanding Service to the Profession and the Association, 2004; election as President, Section of Odontology, Royal Society of Medicine [London] for their bicentenary year, 2004-5; and served as President of the British Society for Dental Research for 2004-6; In 2011 Newell was granted Honorary Life Membership of the British Society for Oral Medicine. The most senior honour was appointment by Her Majesty the late Queen Elizabeth II as a Companion of the Most Excellent Order of St Michael and St George (SMG) in 2011 for services to oral health and to public health internationally.

Newell was a prolific researcher and during his long academic career was supervisor to 30 successful PhD students. He was much loved by his trainees particularly those who came to the UK for postgraduate studies from the Commonwealth Countries. Newell had a remarkable drive in all research activities he conducted on dental caries, periodontal diseases, tropical diseases affecting the oral cavity and oral cancer. He authored many textbooks, published over 600 research articles with a citation index of 35400.

Newell was 85 years old at the time of his death and is survived by his first wife Pauline and his two daughters Sarah and Nicola, their partners, Luke and Murray and 3 grandchildren, Reuben, India and Aurora. His second wife Jeannette, died in 2016. The world has lost a brilliant academic, researcher and a mentor and we have lost a cherished friend.