Direct Retainer is component of partial removable prosthesis used to retain and prevent dislodgement.

1. Classification of
Direct Retainers,
Rests and Rest Seats
Kumari Anjali, IV Year

2. Retainers
Direct Retainers
That component of a partial removable dental
prosthesis used to retain and prevent
dislodgement ,consisting of a clasp assembly or
precision attachment (GPT8).
Indirect Retainers
The Component of a partial removable dental
prosthesis that assists the direct retainer in
preventing displacement of the digital extension
denture base by functioning through lever
action on the opposite side of the fulcrum line
when the denture base moves away from the
tissues in pure rotation around the fulcrum line.

3. Direct Retainers
Intracoronal Extracoronal
Retentive Clasp
Assemblies
Attachments
Semi Precision
Attachments
Precision
Attachments
Suprabulge Infrabulge
Reference Stewart’s Clinical Removable Partial Prosthodontics

5. Direct Retainers
Intracoronal Extracoronal
Attachments Clasps
Attachments
Circumferential Bar
Cast
Circumferential
Combination
Reference : Textbook of prosthodontics by V Rangarajan

7. Rest and Rest Seats
Rest:-
It is a rigid extension of a removable dental prosthesis that prevents movement
towards the mucosa and transmits functional force to the teeth.
Rest seats:-
The prepared recess in a tooth or restoration created to receive the occlusal ,
incisal, cingulum or lingual rest

8. Classification based On
Relation to Direct Retainer
Primary Rests
These are attached to the
clasp assembly and aid in
support
Secondary Rests
These are placed away from
the clasp assembly and
primarily aid in indirect
retention

9. Classification based On
Area Of Placement
Occlusal Rests
Placed on occlusal
surface of posterior teeth
Lingual Rests
Placed on lingual surface
of teeth in cingulum area
, usually canine
Incisal Rests
Placed on incisal edge of
anterior teeth

12. Reference
1. Textbook of Prosthodontics by Dr. V. Rangarajan , 2nd Edition
2. McCracken’s Removable Partial Prosthodontics by Alan B. Carr,11th Edition
3. Stewart’s Clinical Removable Partial Prosthodontics by Rodney D. Phoenix , 4th Edition