A -
Wrong. The man in picture A is Hugo Sanchez, a qualified dentist who also played football for the Mexican national team. Since he has a degree in dentistry, he can evaluate, diagnose, operate on and treat conditions of the oral cavity and the maxillofacial area.
In picture B is some random-ass fat guy in an oversized white labcoat. He doesn't have a degree in dentistry and he doesn't know anything about cavities and surgery. Infact, the only thing he has in common with a real dentist is that he has a poster of a tooth in his rented room.
Allow me shatter your little dream thoroughly. In real life, this "dentist" is probably an unemployed moron who normally plays uncredited two-bit roles in cheap TV serials. He got the break of his life when CP's ad agency rang him up and asked him to don the labcoat for what would be his Magnum-Opus. He cannot perform a dental implant nor does he have a clue about Gingivitis. However, he can tap two sea-shells together and show us that the one labelled Colgate doesn't break whereas the one with a blanked out name shatters to pieces. He has perfect 20/20 vision, but wears glasses just so that he can look mature, caring and wise. He tells impressionable little children that a bacterium is a little green animated gremlin which wears a maniacal grin on its face and carries a sharp trident. But you can't blame him for that, because probably he himself truly believes that bacteria are actually spooky little animated creatures with bulging eyes and sharp spikes on their backs, who wear a look of ghastly shock on their faces while their arms flail about helplessly as they drown in a white wave of flouride foam.
Look at him. I am sure in real life he is a drunkard who gets into arguments with his neighbours and beats up his kids. In fact, I am sure he drinks so much that his trembling hands can never steadily hold a tooth-drill, because he'd be shaking like a duck on a rainy day. He can't hold on to a steady job either, and is upto his neck in debt. And whatever little money he made from this ad film was spent buying more bottles of black rum. He is probably lying in a dazed stupor on his filthy sofa in his 1-bhk Borivili studio apartment right now, with a 6 day old stubble, sprawled amidst empty bottles and cigarette ash, cradling a bottle of cheap rum, with empty cigarette packets strewn all over the floor.
And you take dental advice from this monkey.
Go away. Feel good about it.