Any advice on transitioning from home care to 24-hour nurse care? My mother’s dementia has made it difficult to keep her at home.

Your question is about changing an in home caregiver to a nurse? Cost will at least double.

Know it will be hard for you both and that’s okay. Know that neither of you will be pleased with everything about it and that’s okay. Know that elderly people in a community often know the best and worst places for care and use those local resources to learn from. Know that you’re doing your best and that’s all anyone can do. Know your mother will need an advocate while in a care setting and she’s blessed to have you in that role

No matter what you do to ease a move to MC it will be a difficult transition for her.
DO expect her to decline.
Do NOT expect her to like it.
You can tell her where she is going.
You can take her on a tour.
Let the staff do what they do in trying to get her to participate in activities.
When she says she wants to go home tell her.:
You are home
You are safe

I'm not sure whether you mean to keep mom at home with 24-hour nurse care or if she'll go to a facility where there is 24-hour care.

If you have that choice, it should be a facility. It's very hard to keep someone at home with 24-hour care. Home is not home anymore when that happens, and there's a lot of management you'll have to do even with nurses there. And I do mean nurseS. One can't handle it all.

There will probably come a point that you won’t be able to give appropriate 24 hour care to a demented love one. The loved one can’t help how they are anymore. Their brain, their body is deteriorating. Their capability to care for themselves, even “control” their own bodies or thoughts are fading away….If they were themselves they probably would not want you to have to do that for them. It’s a huge task and takes away your own life and your families… most people have no idea the magnitude of caring for a demented person who no longer has control of their own body processes including their own capacity to think to plan, to dress, to toilet, to bathe, to remember their own family or their own lives….to eat, to swallow…….
I am thankful that there are appropriate facilities with appropriately trained and certified staff in each aspect of patient care to meet the needs of those with dementia caused by any source… Age, disease, genetics, accident….
it is also important for the family to be sure the facility your loved one is in an accredited facility, with excellent “care surveys” from the powers that be in whichever state you live in or country…

Seriously, think long and hard about this