Cavity design is an important step in tooth preparation.Slideshare also shows G.V black classification of cavity(class 1 to class 6). Steps in preparation of class 1 ad class 2 cavity.

1. CAVITY DESIGN
PRIYA AHUJA
DENTAL ( INTERN)

2. DEFINATION -
CAVITY DESIGN IS ESSENTIALLY A BOX IN FORM OF
FLOOR [PULPAL] AND FOUR WALLS.
THREE TYPES OF CAVITIES-
 smooth surface cavities
 root cavities
 pit and fissure cavities

3. TOOTH PREPARATION WALLS
 Internal wall- preparation which
Is not extended into external surface.
 Pulpal wall
 Axial wall
 External wall- wall in the prepare
Tooth that extends into external surface.
 Floor or seat
 fascial wall
 Distal wall
 Lingual wall

4. TOOTH PREPARATION ANGLE
Line angle- it is a junction of two surfaces
of different orientations along the line.
Point angle-it is a junction of three planes
surfaces or three line angles of different
orientation.
Cavosurface angle- formed by junction of
prepared tooth wall and external surface of
tooth.

6. CLASS 2 CAVITY DESIGN

7. SIMPLE COMPOUND AND COMPLEX
TOOTH PREPARATIONS
 SIMPLE- if only one surface is involve
example occlusal preparations.
COMPOUND- if two surfaces are involved
example mesio-occlusal preparations.
COMPLEX-if preparation involve more than
two surface example MOD preparations.

8. G.V BLACK CLASSIFICATION OF CAVITY
[THE GRAND OLD MAN OF DENTISTRY]
 CLASS 1 CAVITY
 CLASS 2 CAVITY
 CLASS 3 CAVITY
 CLASS 4 CAVITY
 CLASS 5 CAVITY

9. G .V BLACK CLASSIFICATION OF CAVITY
CLASS 1 RESTORATIONS
 All pit and fissure restorations are class 1 and are
assigned to three groups as follows-
 restorations on occlusal surface of premolars and molars.
 Restorations on occlusal two third of the facial and
lingual surfaces of molars.
 restorations on lingual surface of maxillary incisor.
CLASS 2 RESTORATIONS
 restorations on proximal surfaces of posterior teeth are
class 2.

10. CLASS 3 RESTORATIONS
 Restorations on the proximal surfaces of anterior teeth that do
not involve the incisal edge are class 3.
CLASS 4 RESTORATIONS
 restorations on the proximal surfaces of anterior teeth that do
involve the incisal edge are class 4.
CLASS 5 RESTORATIONS
 Restorations on gingival third of the facial or lingual surfaces of
all the teeth except pit and fissure lesions are class 5.
CLASS 6 RESTORATIONS
 Restorations on the incisal edge of anterior teeth or the
occlusal cusp heights of posterior teeth are class 6

11. CLASS 1 CAVITY PREPARATION
 Need to provide increased resistance – resistance to fracture of
teeth.
 Enter the bur in distal pit area [ inverted cone diamond bur –
parallel with the long axis of crown] –permits better vision.
 The mesio-distal length will be prepared.
 Pulpal floor initial depth 1.5mm -0.2mm inside DEJ.
 Lingual facial depth could be greater 1.75mm.
 Cuspal and marginal ridge area preservation as much as
possible.
 Outline form should be conservative as possible.

12.  Extension toward cusp tip should be as minimal as
possible.
 Fascial and lingual extension and width are directed
by the caries ,old restorative material or fault.
 1.6 mm thickness of marginal ridge for premolars and
2mm for molars.
 Extending the outline form to sound tooth structure,
remaining caries should be removed.

14. CLASS 2 CAVITY CONVENTIONAL DESIGN
OCCLUSAL STEP-
-similarly like class 1
-conservative connection between occlusal and proximal
portion.
-1.5 mm initial occlusal depth
-Initial extension toward the proximal area
-Go through the marginal ridge, initial pulpal floor depth
exposing the DEG
-DEG serve as a guide for preparation.
-Inverted cone diamond, parallel with long axis of teeth
crown – occlusal convergence.

15. PROXIMAL BOX
 Faciolingual width as narrow as possible.
 Initial depth 1.5mm than follows the rise and fall of the
underlying DEG.
 Pulpal floor relatively flat.
 Preservation of cuspal area.
 Not to cut the adjacent tooth.
 Ideally there is no preparation beyond the proximal
contact.
 Bur always parallel with the long axis of teeth.
 Axial wall 0.2mm inside DEG.

16.  Inverted cone diamond resulted occlusal convergency.
 Remove gingivally any unsupported enamel margins.
 PREPARATION ON THE ROOT-
90 degree cavosurface margin
Depth is 0.75-1mm