tooth extraction

1. PRINCIPLES OF EXTRACTION
The ideal tooth extraction is the painless removal of the whole tooth,or tooth root,with minimal trauma to the investing tissues,so that the wound
heals uneventfully and no postoperative prosthetic problem is created.
PRINCIPLES OF EXTRACTION WITH FORCEPS PRINCIPLES OF EXTRACTION WITH ELEVATORS
1. Expansion of the bony socket 1.Lever principle
2. The use of a lever and fulcrum 2. Wedge principle
3. The insertion of a wedge or wedges 3.Wheel & axle
2. The use of a lever and fulcrum to force a tooth or root out
of the sochet along the path of least resistance. It is the basic
factor governing the use of elevators to extract teeth &
roots.The elevator is the lever of first order & the fulcrum is
located between the input effort & the outputl
load/resistance.To gain mechanical advantage the effort
arm must be longer than the resistance arm
1. Expansion of the bony socket to permit
the removal of its contained tooth,achieved
by using the tooth as the dilating
instrument .Most important factor in
forceps extraction.For success it requires
sufficient tooth be present to be firmly
grasped by forceps blades.Can be dilated
only if the bone is sufficiently elastic’.Most
cases accompanied by multiple small
fracture of buccal plate & the
interradicular septa.
3. Insertion of a wedge or wedges between the tooth root
and the bony socket wall causing the tooth to rise in its
socket.Can be used to split expand and displace the
portion of a substance that receives forces.mechanical
advantage 2.5
4.
THE REMOVAL OF A POST EMBEDDED IN THE
GROUND (A)PERFORMED BY MOVING THE
POST LATERALLY (B) UNTIL THE EARTH
SURROUNDING IT HAS BEEN DISPLACED
SUFFICIENTLY (C) TO PERMIT THE POST TO
BE LIFTED OUT
(A)
(B) (C)