Dr. Greenwall is a Prosthodontist and Specialist in Restorative Dentistry and member of the International College of Dentists since 2015. As well as running a multidisciplinary private practice in Hampstead, London, where she works with a specialist team in the practice (endodontist, periodontist, implant surgeon, oral surgeon and orthodontist), she is a founder member and past Chair of the British Dental Bleaching Society (2008-2013), past chair of  the Alpha Omega Society (2012/13), was past Editor-in-Chief of the journal Aesthetic Dentistry Today for 25 years, and is past President of the Metropolitan London Branch of the British Dental Association (2015/2016). In March 2016 she was awarded the FMC Award for Outstanding Contribution to Dentistry. She is past Char of the London section of the Alpha Omega Society.

Her first book, Bleaching Techniques in Restorative Dentistry, won the award for Best New Dental Book in 2001 – the Second edition of this book, Tooth Whitening Techniques, was published in May 2017 and the 3^rd edition is in process. Her book Success Strategies for the Aesthetic Dental Practice was published by Quintessence in 2011 together with Practice Management Consultant Dr Cathy Jameson. Her new book, written during the Covid Pandemic is called Food Memories: the Cook book. The book was launched in 2023 and all proceeds to the dental charities she established. She has written many papers for scientific journals her new book The Smile Journey was published in 2025.  Dr Greenwall lectures in the UK and internationally on  tooth whitening,  prosthodontics and digital dentistry, aesthetic dentistry, practice management and her dental humanitarian programmes.

In June 2017 she was honoured by the Queen in her birthday honours to receive the British Empire Medal  BEM for her Service to Dentistry in the UK and Abroad. The medal ceremony was held on 17 November 2017 at the Tower of London and then she attended the Garden Party at Buckingham Palace in 2018. In June 2025, she was honoured by the King to receive the Member of the British Empire Medal MBE for services to Dentistry and Charity in the UK and Abroad.

In 2011, Dr Greenwall established the Dental Wellness Trust Charity in the UK and the Dental Wellness Foundation in South Africa which has the motto “Oral Health through Dental Wellness”.  In South Africa, the charity runs innovative oral health programmes to the less fortunate communities and reaches 21 000 children daily in the townships of South Africa. During Covid until 2025. The Dental Wellness Foundation established 12 soup kitchens in Cape Town serving 2 million meals over the last 4 years assisted by 16 community oral health workers affectionately called “Toothbrush Mamas”. In the UK as well as Live Smart Dental and Oral Health Programmes Livesmart Supervised Toothbrushing programmes in schools in England, Luton, London and Newham reaching nearly 40 000 children.