Is it worth applying?

For context im in y12 my predicteds are a*a*a my gcses are 9988888777. I've spoken to my bio teacher about applying dentistry and shes highly discouraged me basically saying theres little hope in even hearing back from any uni as over the past 5 years only 2 people have recieved offers in my 6th form. I've booked my ucat for late August and I'm currently getting around 1800 band 2. Im aiming for at least 2300 band 1. I've shadowed a dentist I've got tons of care home expericne, pharmacy, optician, radiographer, farm, volunteering, etc. I know it'll be really hard and im willing to put effort in but is it that unreasonable to apply?