Another partially retired dentist here. Selection is very different these days, and I think that, to its detriment, the profession has lost the wider base of a spread of dentists good enough academically but brilliant with their hands and/or people (ideally both, but you'd be amazed how far one along has gotten some people- fillings etc are just about following set processes that you will have practised and practised and practised....) 😀
However it has also thankfully lost the old boys club feel that it had when I started- we had to wear skirts on polyclinic- nothing as dignified or appropriate as trousers- and dresses for vivas! Observing life as a GDP would be ideal, but I promise you we will be on our best behaviour and it will all look fabulous, smooth extractions, easy patients etc.
However work experience is also often the privilege of the well connected, so I for one am very pleased that those who cannot get any are not excluded.
Instead, you can forensically go through each dental school website and watch their videos.
Applications: Look at the Dental Schools Councils selection booklet and check each dental school's requirements, and yes, apply strategically. I would suggest treat UCAT as a 4th A level, as most dental schools- not all- rely heavily on it.
I think that as well as my peers' comments , I cannot stress enough how important it is to already like working with your hands, ideally having hobbies that reflect this. Because even if you plan a career in dental public health or some other dry fingered area, the training is the practical repetition and perfection of manual tasks, combined with people skills.
No kids following me in either- far too shrewd! So don't worry about stellar GCSEs and 3A*, as long as you meet requirements. It would be far better and you will be happier in your job if you apply with a genuine interest in people and problem solving, and a love of and skill in using your hands.