Mr Thomas qualified as a dentist in Cardiff in 1976. He was appointed as Deputy Chief Dental Officer to the Welsh Government in 2010, and was named Acting Chief Dental Officer (CDO) later that year following the retirement of the previous CDO, Dr. Paul Langmaid.
Mr Thomas takes up the role with immediate effect.
The Chief Dental Officer is responsible for providing high quality and professional advice to Welsh Government Ministers in relation to dentistry policy, the practice of dentistry and the promotion of good oral health.
Dr Jewell said:
"I am pleased to announce the appointment of David Thomas as our new Chief Dental Officer for Wales.
"David brings to the role a background in community dentistry, dental public health as well as a record in academia, in both a management and research role. He has published widely in academic dental journals and has been involved in the management of Dental Postgraduate Education.
"I would like to thank David for his work as acting Chief Dental Officer since the retirement of Paul Langmaid, and look forward to working with him in his new role."
Mr Thomas said:
"I am delighted to have been appointed to the role of Chief Dental Officer for Wales and look forward to working with the Welsh Government Ministers on the many aspects of dental policy and practice, including promoting and improving the dental health of the people of Wales."