Hello OP.
Many dementia patients become very aggressive while they're being changed. They do not understand what is happening, but they experience distress because it isn't normal for other people to assist us in this way. We spend our whole lives being completely private in our toilets and bathrooms.
The patient's response to intimate care is to fight the carers, because they believe they're being attacked.
This means that the carers are in danger, and the care cannot be achieved if the patient is kicking and punching them. The patient can also injure themselves in these circumstances.
In order for personal care to be given as easily and safely as possible, it is sometimes necessary for three or four carers to be there. Yes, they'll be holding the patient's hands, and one will be talking to him. The rest will quickly clean the patient and make him comfortable.
Dementia is a progressive illness and your dad's capabilities when he was at home will already have deteriorated.
I'm sorry you're so upset about this.
In my many years as a nursing home matron, I've seen countless five foot nothing women patients who needed three or four carers at times.
I've even seen a lady of 92 who weighed about six stone, and who was 5' 2" tall, needing four paramedics and two police officers (and me) to get her out of her house and into an ambulance.
Don't underestimate the strength of a very severely demented person.
Why don't you go and watch while they change your dad? Without him being aware that you're there. And do ask the nurses to explain why they need four of them.