ABRASIVE & POLISHING MATERIALS

BY: Rabia ZULFIQAR

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: Hardness Rate of movement Shape Particle size Pressure Mechanical properties of abrasive particles

Commonly Used Abrasive In dentistry:Diamond , Carbide , Sand , Emery, Kiesulguhr, Garnet, Zirconium silicate , Pumice

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.

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.

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.