When a tooth or teeth have been lost it can be successfully be replaced by removable partial dentures.
Removable partial dentures can either be plastic(temporary)or metal frame.

These dentures are far superior to the plastic dentures.

They are made from an extremely hard but flexible material called cobalt chrome,
The big advantage of these dentures is,strength,stability,comfort,tooth and gum friendly and the fact that it covers much less of the oral soft tissues especially the palate with the advantage of improved taste.
Metal frame dentures is supported by your existing teeth, where plastic dentures are supported by gum only.Plastic partial dentures are so called “gum strippers”,as in most cases, you get gum recession due to this type of denture.
Clasps and rests are part of a metal frame denture and keeps it secure.
There is some misconception that the clasps on dentures is the cause of cavities.
The only reason for cavities associated with clasps,is the lack of oral hygiene.
It is important  to take the denture out when cleaning your teeth.This should be done after every meal,if possible.
The denture,like your teeth,attracts bacterial plaque and should regularly be cleaned both on the outside as well as the inside.A toothbrush or nailbrush with some dish washing soap works the best.Failure to clean your denture will lead to cavities,gingivitis and foul smelling breath(Halithosis)
When cleaning your denture,put some water in the basin,that,should the denture fall,it cannot be damaged.If a metal frame denture drops on a tiled floor,it might result in damage,after which it will affect the fit of the denture.
NEVER try to adjust the clasps yourself or by a friend!!!This is the only reason why clasps fracture.This can not be repaired and you will need to have the denture remade.Adjustments to your denture should only be done by a qualified professional.