2. ABRASION
''Abrasion is a process by which surface of a material
is made smooth by rubbing or grinding''
'' the material used for abrasion called
abrasive materials''
FACTORS AFFECTING ABRASION:
๏ผ Hardness
๏ผ Rate of movement
๏ผ Shape
๏ผ Particle size
๏ผ Pressure
๏ผ Mechanical properties of abrasive particles
Commonly Used Abrasive In dentistry:
Diamond , Carbide , Sand , Emery, Kiesulguhr
, Garnet, Zirconium silicate , Pumice
3.
4. POLISHING
''Polishing means the production
of a smooth glossy mirror like
surface on a metal without use
of a film''
POLISHING MATERIAL:
'' Unlike abrasive, a polishing
material does not cut a groove,
but causes the fine scratchesto
be filled in and so produce a
perfectly smooth surface''
FOLLOWING POLISHING
AGENTS ARE USED:
calcium carbonate, Rouge , putty
powder , chromium oxide ,
Tripoli , Cuttle , Electrolytic
Polishing , Burnishing.
5. DENTIFRICES:
This term includes both the tooth pastes & tooth
powders.
Function: ( help the tooth brush in cleaning the accessible
surface of teeth to remove the stain and debris)
COMPOSITION:
1- flavouring agents: (provide pleasant & acceptable taste)
2-Detergents: (decresed the surface tention of dentrifices, remove
debris from teeth surface e.g. sodium lauryl sulphate )
3-Abrasives: ( provide cleaning, it should be hard enough to remove
stains from teeth but should not cut into or scratch tooth surface)
PASTES TYPE DENTIFRICES:
Water : As solvent for colouring agents & soluble ingredients. to
improve consistency and appearance of paste.
Binders : Are included in paste type formulation to prevent the
separation of liquid & solid components.
6. DESENSITIZING AGENTS:
๏ Tooth pastes are formulated specially for purpose of
reducing the hypersensitivity of teeth.
๏ Hypersensitivity:
''it is usually a result of erosion & abrasion of teeth
near thier cervical margins. ''
๏ These conditions can also result from wrong direction of
tooth brushing.
๏ Desensitizer usually present in tooth paste are ,
Strontium,
potassium chloride, formaldehyde.
7. DESENSITIZING AGENTS:
๏ Tooth pastes are formulated specially for purpose of
reducing the hypersensitivity of teeth.
๏ Hypersensitivity:
''it is usually a result of erosion & abrasion of teeth
near thier cervical margins. ''
๏ These conditions can also result from wrong direction of
tooth brushing.
๏ Desensitizer usually present in tooth paste are ,
Strontium,
potassium chloride, formaldehyde.