1. Black`s Rules and New
concepts of cavity
designs.
Operative dentistry

3. G.V. BLACK’S (1980)
ESTABLISHED PRINCIPLES
1. Etiology of dental caries
( known at that time )
2. Materials available ( known at
that time )
3. Histology of Tooth structure
( known at that time )
4. Structural mechanics

4. G.V. BLACK’S RULE OF
CAVITY PREPERATION
1. Tooth Morphology
2. Outline Form
3. Resistance Form
4. Retention Form
5. Convenience Form
6. Removal of Disease/caries
7. Extension For Prevention
8. Debridement/toilet of Cavity
Preperation
9. Biologic Form

5. REQUIREMENTS OF
TOOTH PREPERATION
A. Dentinal tissues
1. Structures
2. Properties
B. Restorative Materials
1. Properties
C. Structural Mecanics
1. Physics Laws

6. MODIFICATIO
REQUIREMENTS
1. Root Caries
2. Non Carious Lesion
3. Latest Concept of
a. Etiology of caries
b. Mineralization of enamel
c. Remineralization of enamel
4. Modern restorative materials
5. Latest knowledge of histology
of tooth stucture.

7. PROPERTIES OF
MATEIALS
1. Knoop hardness
2. Thermal expansion
3. Modulous of elasticity
4. Average opacity

9. CLINICIAN’S
CHALLENGE
REQUIREMENTS FOR
RESTORATION
1. Remove diseased tissue as
necessary
2. Restore the integrity of toot
surface
3. Restore the appearance of
tooth surface
4. Restore the function of tooth

10. MODERN CONCEPT
1. Micro-cutting
2. Preservation
3. External grooving
4. Internal tunnel

11. Principles of cavity
design
• Gain access to the caries
• Remove the caries
• Put the instrument down,look,
think and design
• Complete the preparation.

12. Put the instrument down,
look, think and design
• The final choice of restorative
material
• How to retain the restorative
material in the cavity?
• Design features to protect the
remaining tooth tissue
• Design features to optimize the
strength of the restoration.
• The shape and position of the
cavity margin