Biomed and Dentistry are two very different career options, although naturally there will be similarities between the two.
Biomed focuses on the functioning of cells, organs and systems of the human body. It's very much a science, and many people who study biomedical sciences will end up working in a laboratory environment; it tends not to be a person-facing role. So although you'll likely work as part of a team, this is a less person-focused option.
By comparison, dentistry focuses more on the operative management of oral and dental disease and the vast majority of those who complete a dental degree will work in the clinical environment in patient-facing roles. You'll work closely with your colleagues in the clinical environment, but also will be dealing with large numbers of patients - dentistry is a very 'social' job and communication is key to being a successful dentist.
So I think the key to helping you make your decision will be to do with how much patient contact you want - whilst both professions are very focused on completion of manual activity, if you're a people person, dentistry is probably more for you! As a dentist, I love speaking to people, and helping to relieve their pain, improve their dental health, so I cannot recommend the profession enough!
Hope this helps! Any questions, feel free to ask