MECHANICAL PRINCIPLE IN TOOTH EXTRACTION

1.LEVER PRINCIPLE OF FIRST ORDER :-
 - It has three basic component :- fulcrum
                                                         - effort
                                                         - load
- To gain a mechanical advantage, the effor  arm on one side of fulcrum should be longer
   than the load arm on other side of fulcrum.

- APPLICATION
1.Forceps
- to gain a mechanical advantage grip should be farther from the fulcrum ane the blade
  should be shorter.
2.Elevators
- handle of the elevator represents the effort and working end which engages between the
  teeth represents the load.
- MECHANICAL ADVANGAGE OF LEVER IS = 3.O

2.WEDGE PRINCIPLE :-
- effort is applied to the base of the plane and resistance has its effect on the slant side.

-APPLICATION
1.Forceps
- tip of forceps inserted between the mucoperiosteum and surface of tooth, beaks are
  inserted further, the bony socket expanded and result in slow seperation of  periodontal
  ligament from the bone.
2.Elevators
- straight elevator is applied between tooth and bone to separate attachement of   
  periodontal ligament from bone.

- MECHANICAL ADVANTAGE OF WEDGE IS  = 2.5

3.WHEEL AND AXLE
- Effort is applied to the circumfernece og wheel., which turns the axle so as to raise
   the weight.
- Greater the diameter of wheel, more is mechanical advantage.
- APPLICATION
1.Forceps
- applying this priciple, the periodontal ligament gets ruptured due to bodily rotation of tooth.
2.Elevators
- Cross bas elevators are used to remove mandibular roots based on this principle.
 - Working point of elevator is engaged into space between two roots and bone and the
   handle is rotated.
- MECHANICAL ADVANTAGE OF WHEEL AND AXLE IS = 4.6