Find a dentist that does sedation and get them to give him something to relax prior to appointment, or if you cannot do that get his General Dr to prescribe something you can give him in advance of appointments.
I have some thoughts - there must be medication to make them really calm or even possibly put them out or to sleep. And, while this is not a good answer, you may have to accept something - if they absolutely refuse to cooperate and everything has been tried without any luck, well, they create their situations and no one can help - so let them suffer with the consequences. What else can you do - other than forcibly tie them down and do what needs to be done.
My husband, who has dementia, had a dental appointment last week. Because he doesn't brush like he should and won't let me help, he has his teeth cleaned every three months. I stayed at his side the entire time he was being treated. At times, he didn't want to open his mouth. The hygienist was very patient with him. Between us, we got him to "open wide" and get the procedure done. He has one tooth that needs a crown. The preliminary procedure will take about two hours. Not sure how that will go. He responds to calm and reassuring tone of voice. Anger and/or frustration tends to make him uncooperative. Dementia is sometimes overwhelming. Hugs to you and your mom.
That sounds like a lot to put him through. Crowns are tough with the grinding, the impressions, and those awful cords! Does he really need to go through that at this stage in life? If I get to that point, I want my kids to pull my teeth. Just my opinion, but I had a congenital dental defect that has given me many hours in the dentist's chair. I would feel so bad about putting anyone else through that. Just be sure, please, that it's what you and the rest of the family want, and not just the dentist following the same protocol as s/he does with non-dementia patients.
I had to do this with my mother. She didn't understand what was going on. If he has to get a tooth extracted, go to an oral surgeon and explain the situation. They may have to anesthitize him to put him out during the procedure. I now told her assisted living case manager that we no longer want regular dental appointments. I'd only have her go if she's in pain. Also no hospitalization except in extreme emergency. When she was in the hospital it was the same thing. She didn't understand what was happening to her and she couldn't follow instructions. She tore the oxygen tubes off and bit the nurse.
Since his cooperation to open his mouth for a prolonged length of time is the gateway, I agree that anti-anxiety medication from his doctor, and then maybe nitrous from the dentist may be the best strategy.
To Grandma1954's good point about post-procedure grogginess and unsteadiness, you should plan to have a transfer wheelchair and another strong person there to get him out of the chair, back in the car and then into his residence.
Talk to your father's doctor about anti-anxiety medication. Your father should be medicated about an hour before his visit so he can relax and cooperate with treatment.
I suppose if it hurts enough the person would open their mouth to let you see the problem. Best for a family member to get a flashlight and ask the person to show you where it hurts and see if you can see if it's a broken tooth, loose tooth or if it looks rotten. Very hard to have a Dentist do that unless they put the person under which can be dangerous for the person depending on age.
There are mobile dentists that special in elderly and disabled dental care. Maybe try to Google one in your area and call to see if they feel they can help. One visits my Mom's facility but they also do house visits. They are a bit more expensive usually, just fyi.
When my Husband was no longer compliant at the dentist (and the dentist was a LONG time very good friend of my Husband's) I decided that I would not stress him out and deal with the stress of putting him in a twilight sleep, or full anesthesia knowing that any anesthesia can take a toll on someone with dementia. AND trying to keep him for trying to pick at what would possibly be open wounds in his mouth when they pulled teeth. (and they would have had to) Trying to do oral care on someone with dementia can be difficult enough when just trying to brush teeth let alone trying to do it after oral surgery. (I even tried giving him an oral medication to combat the anxiety and be more compliant and that did not work it just made it more dangerous to get him to walk to the car, and get him into the car safely after the appointment)
In your dad's case if the tooth is bothering him he may have to be sedated. An oral medication might work but it can have a more lasting effect. The dentist would try Nitrous oxide that would not be as long lasting but he would have to get the mask on him.
I never even thought of having to deal with post-surgical conditions, dental or otherwise, with dementia patients. Oh, dear! So many situations I read about on this forum make me realize how fortunate I have been in the care taking I have done for family members. I have not had to deal with most of these problems!
To Grandma1954's good point about post-procedure grogginess and unsteadiness, you should plan to have a transfer wheelchair and another strong person there to get him out of the chair, back in the car and then into his residence.
Best for a family member to get a flashlight and ask the person to show you where it hurts and see if you can see if it's a broken tooth, loose tooth or if it looks rotten.
Very hard to have a Dentist do that unless they put the person under which can be dangerous for the person depending on age.
Trying to do oral care on someone with dementia can be difficult enough when just trying to brush teeth let alone trying to do it after oral surgery.
(I even tried giving him an oral medication to combat the anxiety and be more compliant and that did not work it just made it more dangerous to get him to walk to the car, and get him into the car safely after the appointment)
In your dad's case if the tooth is bothering him he may have to be sedated. An oral medication might work but it can have a more lasting effect. The dentist would try Nitrous oxide that would not be as long lasting but he would have to get the mask on him.