Precision Attachments
1. Classification Of Precision Attachments 2. Difference Between Rigid And Resilient 3. 4. 5. 6. 7.
Attachments Clinical Indications For Ball Attachment Clinical Indication For Slide Lock Attachment Four Principles Of Denture (Support -retention guidance-stability) What Interlock Is Used For? When Double (Telescope) Crowns Used?
1. Classification Of Precision Attachments
a) Based on location or shape and form:
1. 2. 3. 4.
Extracoronal Intracoronal Radicular/Intraradicular Stud type Bar Rigid: any attachment where mechanical locking is used (clasp, lingual arms, springs, ball and sockets etc). The RPD is held in place firmly and the abutment teeth are subjects to all of the forces in the mouth at al times
Passive: Attachment that provides a free movement of the male when the abutment teeth are exposed to excessive forces.
b) By function of the attachments:
1.
2.
1. Classification Of Precision Attachments
Studs Miscellaneous 1. Telescopic prosthesis 2. The screw-tube attachment These two auxilliary attachments used when preparations are not parallel for some reason, or if superstructure needs to be split into segments for easier management
1. Classification Of Precision Attachments
precision attachments are the functional mechanical
parts of the removable partial denture made of plastic, metal or a combination of both.
They consist of two parts referred as the 'male' (or
patrix) part that is fixed to a crown inside the patient's mouth and a 'female' (matrix) part which holds the partial denture. and the aim of the precision attachment is to give the patient maximum comfort and ease while wearing, inserting or removing.
The patient can insert and remove the partial dentures
2. Difference Between Rigid And Resilient Attachments
Non-resilient (rigid) attachments are highly
stable connectors with very slight movement in function. (Kennedy Class III&V)
Resilient attachments are stress directing
attachments for Kennedy Class I and II cases which place occlusal load on both abutment teeth and the edentulous ridge.
3. Clinical indication for ball attachment
Large distance between implants, contraindication
for bar splinting; Pointed anterior jaw ridge segment Diagonal arrangement of implants in the arch Difficulties with oral hygiene (elderly patients) Financial considerations
4. Clinical indications for sliding lock attachments:
If bar constructions are planned upon implants positioned relatively close to one another in the arch, active retention devices, ex. bar matrices, should be avoided. Rather, passive retention components sliding lock is advantage in such compromised situations: When only short bar is available; this situation arise because it was planned that way preoperatively, or implants placed incorrectly, if an implant is lost so modification of original structure is necessary. Particularly in this case locking device is a ready solution.
5. Four Principles Of Denture (Support-Retention-Guidance-Stability)
Support is the principle that describes how well the
underlying mucosa keeps the denture from moving vertically towards the arch. Stability is the principle that describes how well the denture base is prevented from moving in the horizontal plane, and thus from sliding side to side or front and back. Guidance: 2 or more surfaces of abutment parallel to each other and to the path of placement. Guide surface should extend vertically about 3mm far from gingival margin. Retention is resisting vertical forces from dislodgement accomplished by mechanical retaining element, clasp and precision attachment.
6. What Interlock Is Used For?
Fixed partial denture segmentation Alternative to conventional clasp partial dentures In Precision and semi-Precision partial dentures .
7. When Double (Telescope) Crowns Used?
In the restoration of a gappy set of teeth with
removable dentures their advantage lies in the problem-free enlargement of the dentures. It is also suitable if one of the pillar teeth was removed. reduced bone density due to age or oral disease
