Prof. Marinello passed his Board examination from the University of Zurich. He spent one year as a General Dentist in a Pediatric Clinic. He served as Assistant Professor and acting head of the Dental Public Health Clinic and was Assistant Professor, Department of Fixed and Removable Prosthodontics and Dental Material Sciences (Prof. P. Schärer), University of Zurich.
He also served as a Visiting Research Professor, Department of Periodontology (Prof. J. Lindhe), at the University of Gothenburg, where he received his Master of Science degree. He was Associate Professor and Head of Periodontology, Department of Preventive Dentistry, Periodontology and Cariology at the University of Zurich.
From 1995 to 2015 he was full-time Professor and Chairman of the Department of Reconstructive Dentistry and Temporomandibular Disorders at the Dental School of the University of Basel.