If your horses teeth are done on a routine basis, wont the horse get used to & accept the procedure more readily. Just a thought, because I would say are more likely to to play up if the only time anyone looked at their teeth was when work needed doing. My dentist is very good & if there is no work to do, he wont do it, but ours are done every 6mths & have never needed anything major doing yet. The only time was last yr when the pony we had on loan had not been done for awhile & ended up needing to be sedated as he got very stressed by it all.
Our 24yo (ish) Dales mare has her teeth checked once a year or every other year (not 6 months i know, none of ours get checked that often) and her teeth were perfect didn't need anything doing to them each time, she has lived out 24/7 all her life only gets hard feed once a week when she is ridden.
I am guilty of not changing numnahs as often as i should, not grooming thoroughly, my horses only get fed (when out 24/7) when i bring them in to ride them, i leave a headcollar on Holly 24/7 (she can be hard to catch), my tack is in dire need of cleaning!