our team


The team at Triangle Dental
in Tilehurst, Reading


Giles Derry - GDC registration no: 54888

Giles Derry
I qualified from Guy’s Hospital Dental School in 1980 and joined Triangle Dental in 1984. I enjoy all aspects of dentistry and offer my patients a wide range of treatments. I believe strongly in the prevention of dental disease.

All my patients have regular appointments with our hygienists to help keep their teeth and gums in good health. Teeth should look good and feel good!

I am married to Lesley who works for the British Dental Association in London. We live in Chieveley and are keen gardeners and keep chickens.

First and emergency visits

Brian Holmes - GDC registration no: 57810

Brian Holmes
I qualified from Queen’s University Belfast Dental School in 1983. Throughout my career I have maintained a keen interest in postgraduate dental education – always interested in discovering latest techniques to help me improve my dentistry.

I joined Triangle Dental in 2001. In 2005, I was awarded the Diploma in Postgraduate Dental Education by the University of Bristol. The Triangle aim of trying to achieve maximum prevention of dental disease is something that I feel committed to and enjoy working closely with all of the Triangle team, including our dental hygienists and dental health educators.

I live near Newbury with my wife and 3 daughters.

Donna Judge - GDC registration no: 83476

Donna Judge
I qualified from the University of Birmingham in 2004. I joined Triangle Dental in 2013, having worked in private dental practices since 2006. I enjoy treating all aspects of dentistry and particularly like showing patients that it can be a lot more pleasant than they anticipate. It is always so rewarding for me when nervous patients willingly return, with a smile, for more!

I am an Inman Aligner trained dentist. This is a removable appliance which efficiently and safely straightens front teeth over a period of 8 – 20 weeks

I regularly attend courses to keep abreast of the current thinking in Dentistry and am a member of two dental study groups, who meet several times a year and where I can participate in lectures from renowned world speakers.

Christopher Read - GDC registration no: 212435

Christopher Read

Jonathan Cowie - GDC registration no: 245635

Christopher Read
I qualified from Peninsula Dental School in 2011 after completing a degree in Biomedical Science in 2006. Since then I have gained hospital experience before returning to general dental practice, working in a number of practices from Cornwall to Cambridgeshire.

I joined Triangle Dental in 2016 and have enjoyed getting to know my patients and the Triangle team. I strive to provide up-to-date quality dentistry for my patients, based on the latest research. 

Prevention has always been key to reducing the amount of dental treatment needed. Having an in-house preventive dental unit and a team of expert hygienists really helps to reduce the amount of dental decay and stabilise gum disease.

I live with my wife and daughter in Wokingham and enjoy travelling, skiing, swimming and flying, when I get a few spare minutes!

I very much enjoy lifelong learning and have gained three degrees, graduating in 2004, 2006 and 2013 from Newcastle and Sheffield Universities. Although I have worked in different professions I have found my calling in Dentistry and could not imagine doing any other job. I joined the Triangle team in early 2017 having previously worked in other private and NHS dental practices.

I am very much in tune with the modern ethos of preventative dentistry, as is the whole Triangle practice, as well as our ethos of continued learning in dentistry. I particularly enjoy complex restorative dentistry and relish the art of making the strongest possible tooth restorations look indistinguishable from natural teeth. I think that visiting the dentist should be a pleasant experience and that is always our aim at Triangle.

See Jon's video in our Gallery page.


At Triangle Dental, our team of experienced dental hygienists will help you achieve and maintain healthy gums and will prepare a tailored preventive maintenance programme that is based on your needs
  • Heather Chard DDH - GDC registration no: 5131, joined Triangle in 2007
  • Gemma Chapman BSc-GDC registration no: 244633, joined Triangle in 2016
  • Bridget Grantham EDH - GDC registration no:1858, joined Triangle in 1993
  • Susan Mackie EDH - GDC registration no: 6475, joined Triangle in 2004
  • Helen Thame EDH - GDC registration no: 1530, joined Triangle in 2002
Gemma is also trained as a dental therapist and can provide simple fillings. Whilst some children may not like having a filling done Gemma has a way of making them relax and almost enjoy their appointments with her. 

Dental health educators

Our team of qualified dental health educators (Jane, Zoe, Katie and Laura) manage our preventive dental unit, where children (and their parents) are shown how to brush their teeth and gums and learn about the importance of a healthy diet. This can really make a difference and help children to achieve a healthy mouth for life. 

We've designed the preventive dental unit with children in mind and so it’s fun and definitely not clinical.  

Dental nurses 

Nurses: Dentists can’t care for our patients without support from our team of experienced nurses. The nurse will make sure the dentist has everything they need when you are in the surgery – some would say that they are worth their weight in gold! 

Practice manager

Dee Sadler
Dee Sadler joined Triangle Dental in 1984, initially as a receptionist, but soon took on the role of manager the practice. She makes sure that the practice runs smoothly and that we comply with our professional responsibilities – and always with a smile. She is a long-standing member of the Association of Dental Administrators and Managers and works closely with other practice managers in the area. 

If you have feedback about any aspect of the practice, please let Dee know. 


Receptionists: Our receptionists are a great source of information about the practice and can help you with booking appointments at convenient times, explain our pricing structure and payment methods. They are usually your first point of contact with the practice and will do their utmost to help you. 
For dentists and dental hygienists in Tilehurst, Reading contact Triangle Dental on

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