1. Periodontology Unit, Faculty of Odontology, University of Santiago de Compostela & Medical-Surgical Dentistry Research Group, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain.
2. Clinical Neurosciences Research Laboratory, Health Research Institute of Santiago de Compostela, Santiago de Compostela, Spain.
3. Periodontology Unit, UCL Eastman Dental Institute & NIHR UCLH Biomedical Research Centre, University College London, London, United Kingdom.