Class I Cavity preparation

1. Operative
Dentistry
Dr.Kareem. A. Lotfy
Assistant Lecturer of
Operative Dentistry

2. Dental Caries: Is defined as a microbial
disease of the hard structure of teeth,
which results in localized
demineralization of the inorganic portion
and destruction of the organic substances
of the tooth

4. Classification
of Dental
Caries
There Are several classifications of
Dental Caries:
• Based on Site
• Based on Extent of Caries
• Based on number of Tooth
surfaces involved... etc

5. The Most widely
accepted
By G.V. Black

7. Class I caries
These are pit and Fissure type cavities that
involves the occlusal surface of molars and
premolars, The occlusal 2/3 of Buccal or
lingual surfaces of Molars and Palatal pits in
maxillary anterior teeth

8. G.V BLACK
Class I

9. Class I
Cavity
preparation

11. In case of initial carious lesions, access is obtained
by employing a small round bur (by giving a punch
cut)
In big carious lesion, access is obtained easily by
breaking down the undermined enamel overlaying
the carious dentin using fissure bur or 245 bur
Initial Cavity
preparation

12. OUTLINE AND INTIAL
DEPTH
The outline form should describe a symmetrical design running along
all pits, fissures and angular grooves between the cusps with a
minimum thickness (Sweeping Curves)
Sufficient cavity Depth (1.5-2mm)

13. SMOOTH FLOWING
REGULAR CURVES
NO SHARP LINE
ANGLES

14. CAVITY WIDTH 1/4 INTERCUSPAL
DISTANCE ( 1-1.5 MM)

15. MESIO-DISTAL EXTENSION :
MARGINAL RIDGE WALLS
SHOULD BE 1/2 DISTANCE
FROM THE CREST OF EACH
MARGINAL RIDGE

16. Resistance Form
FORM GIVEN TO THE CAVITY TO PROVIDE
SUFFICIENT AMOUNT OF TOOTH STRUCTURE TO
RESIST FORCES DIRECTED IN THE LONG AXIS OF
THE TOOTH AND PROVIDE A STRONG, STABLE
SEAT FOR THE RESTORATION THROUGH MINIMAL
EXTENSION OF EXTERNAL WALLS TO REDUCE
WEAKENING THE TOOTH

17. Retention Form
FORM GIVEN TO THE
CAVITY TO AVOID
DISLODGEMENT OF
RESTORATION

18. SPECIFICATIONS
1.Facial and lingual walls converge occlusally
2.Mesial and Distal walls diverge occlusally
3.Internal angles are defined but not sharp
Retention Form

21. Outline All pits and Fissures are included, Following the curves with
distinct Cavo surface angle
Cavity Depth 1.5-2 mm
Cavity Width 1-1.5 mm
Divergence of M / D
walls
< or = 10 degrees
Convergence of B/L
Walls
Minimal Occlusal convergence
Cavo surface angle 80-100 Degrees
Marginal Ridge width At least 2mm
pulpal Floor Smooth and Flat

22. CAVO SURFACE
ANGLE
Angle between prepared
tooth wall and External
tooth surface

23. Final tooth preparation
steps
1.Removal
of
Remaining
Carious
Dentin

24. Final tooth preparation
steps
Obtaining secondary Retention & Resistance form
Finishing of Enamel walls
Finally: Cleaning, Inspecting (Toilet of the cavity)

25. Any
Questions
FEEL FREE

26. STAY TUNED
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