Class I cavity preparation for com
A Class I cavity involves pits and fissures on:
-Occlusal surfaces of molars and premolars
-Buccal/lingual pits of molars
-Lingual pits of maxillary incisors
Algorithm of Preparation
Access Cavity Outline
* Entry via fissure using a high speed round or pear-shaped/short
cylinder bur (blue or green) High-speed
* Follow carious dentin while preserving sound enamel (diamond)
round bur
Caries Removal
* Use slow-speed round bur or hand excavator to remove infected dentin
Cavity Shape
* Conservative outline: no extension for prevention
* Rounded internal line angles
* No retention elements required (composite bonds adhesively) slow-speed (carb
* Smooth cavosurface margins (90°) round bur
*Smooth and refine enamel margins. Margins should be well-defined and
not beveled in Class I, unless extending slightly onto enamel (red and
yellow high-speed diamond burs)
Obtain Convenience Form
*Modify the cavity shape for visibility, access, and instrument
placement.
red and yello
In Class I, usually already convenient due to occlusal location.
olive high-sp
diamond bur
Clean and Dry
* Use water spray → air-dry (avoid overdrying dentin)
Q: Is a minimum depth required in
Class I cavity preparation?
A: No. Composite restorations do no
specific depth for retention; the dep
the extent of caries.
Q: Why are rounded cavity
during polymerization?
A: Because composite resin sh
, Class II Slot Cavity Preparation fo
Resin (Without Occlusal Box)
A Class II lesion involves:
• Proximal surfaces of premolars and molars
• Lesions may be approached from buccal or lingual
• Occlusal surface is preserved if not carious
Algorithm of Preparation
Access Cavity Outline
• Insert a metal matrix band to protect the adjacent tooth surface High-speed
during access. Insert a wooden or plastic wedge interproximally (diamond)
to protect the gingiva and slightly separate the teeth. round bur
• Use a round or pear-shaped high-speed carbide bur. Position
the bur in the distal occlusal pit, close to the marginal ridge.
Orient the bur perpendicular to the occlusal surface and
parallel to the long axis of the tooth.
•Penetrate through enamel into superficial dentin while
maintaining conservative occlusal outline.
• Direct the bur horizontally toward the distal proximal surface
(tunneling). Reach the proximal wall and remove the proximal slow-speed (carb
enamel wall to expose carious dentin. round bur
• Create clean buccal, lingual, and gingival walls with 90°
cavosurface margins.
• Use a slow-speed round bur or spoon excavator to remove
infected dentin.
• Smooth all internal walls and round the internal line angles.
• Shape the axial wall to be slightly convex, following the tooth’s red and yello
external contour. olive high-sp
diamond bur
• Confirm that there is enough space for matrix and wedge
placement.
Clean and Dry
• Rinse thoroughly
• Gently air-dry without desiccating dentin
A Class I cavity involves pits and fissures on:
-Occlusal surfaces of molars and premolars
-Buccal/lingual pits of molars
-Lingual pits of maxillary incisors
Algorithm of Preparation
Access Cavity Outline
* Entry via fissure using a high speed round or pear-shaped/short
cylinder bur (blue or green) High-speed
* Follow carious dentin while preserving sound enamel (diamond)
round bur
Caries Removal
* Use slow-speed round bur or hand excavator to remove infected dentin
Cavity Shape
* Conservative outline: no extension for prevention
* Rounded internal line angles
* No retention elements required (composite bonds adhesively) slow-speed (carb
* Smooth cavosurface margins (90°) round bur
*Smooth and refine enamel margins. Margins should be well-defined and
not beveled in Class I, unless extending slightly onto enamel (red and
yellow high-speed diamond burs)
Obtain Convenience Form
*Modify the cavity shape for visibility, access, and instrument
placement.
red and yello
In Class I, usually already convenient due to occlusal location.
olive high-sp
diamond bur
Clean and Dry
* Use water spray → air-dry (avoid overdrying dentin)
Q: Is a minimum depth required in
Class I cavity preparation?
A: No. Composite restorations do no
specific depth for retention; the dep
the extent of caries.
Q: Why are rounded cavity
during polymerization?
A: Because composite resin sh
, Class II Slot Cavity Preparation fo
Resin (Without Occlusal Box)
A Class II lesion involves:
• Proximal surfaces of premolars and molars
• Lesions may be approached from buccal or lingual
• Occlusal surface is preserved if not carious
Algorithm of Preparation
Access Cavity Outline
• Insert a metal matrix band to protect the adjacent tooth surface High-speed
during access. Insert a wooden or plastic wedge interproximally (diamond)
to protect the gingiva and slightly separate the teeth. round bur
• Use a round or pear-shaped high-speed carbide bur. Position
the bur in the distal occlusal pit, close to the marginal ridge.
Orient the bur perpendicular to the occlusal surface and
parallel to the long axis of the tooth.
•Penetrate through enamel into superficial dentin while
maintaining conservative occlusal outline.
• Direct the bur horizontally toward the distal proximal surface
(tunneling). Reach the proximal wall and remove the proximal slow-speed (carb
enamel wall to expose carious dentin. round bur
• Create clean buccal, lingual, and gingival walls with 90°
cavosurface margins.
• Use a slow-speed round bur or spoon excavator to remove
infected dentin.
• Smooth all internal walls and round the internal line angles.
• Shape the axial wall to be slightly convex, following the tooth’s red and yello
external contour. olive high-sp
diamond bur
• Confirm that there is enough space for matrix and wedge
placement.
Clean and Dry
• Rinse thoroughly
• Gently air-dry without desiccating dentin
