cavity preparation class 1

CLASS 1 CAVITY PREPARATION

Placed in pits and fissure lesions that occur in one or more of the ff:

a. Occlusal surfaces of molars and premolars

b. Occlusal 2/3 of buccal and lingual surfaces of molars

c. Lingual surfaces of anterior teethd. Any other unusually located pit or fissure

involved with decay

COMMON FEATURES

Outline form consists of smooth curves that avoid

occlusal eminences like cusps and ridges

Uniform depth of 1.5-2 mm from CSM

Or 0.5-1 mm from the DEJ

Proximal walls are perpendicular to the pulpal

floor or diverge pulpo-occlusalyProximal walls located 1.6-2

mm from the proximal surface

Round internal line angles

Buccal and lingual walls converge pulpo-occlusally

Butt joint or 90˚ CSM

Proximal walls follow contour of proximal surface

Pulpal floor is flat and usually perpendicular to the long axis of the tooth

DESIGN 1

PROCEDURE

Bucco-lingual cross-section

Mesio-distal cross-sectionInternal

Anatomy

DESIGN 1

Maxillary premolar“dumb-bell”-shaped

Mandibular 1st premolarCircular, resembling snake eyesMandibular 1st premolar“dumb-bell”-shapedMandibular 2nd premolarY-shaped

Mandibular 1st molarElongated

Mandibular 2nd molarElongated

Maxillary molarElongated

Maxillary molarMesial “kidney” shapedDistal “heart” shaped

LOCATION:Occlusal surfaces of molars & premolars

INDICATIONS:• caries penetration into dentin does not exceed 0.5mm-1 mm• involvement of enamel or pits and fissures will not widen more than ¼ intercuspal distance• good oral hygiene & low caries index• Areas of mouth with low cariogenic activity

DESIGN 2

LOCATION:Occlusal surfaces of molars & premolars

INDICATIONS:• caries cone in dentin extend 1 mm or more from DEJ• preparation involvement is more than ¼ ICD• as preventive measure in patients with high plaque & caries index• for teeth with intact cusps

Shapes similar to design 1 but there are more deviations from

shapes and less curved outline and greater surface dimensions

Margins similar to design 1 but closer

to cusp tips and crests of ridges

Bucco-lingual cross-section

Pulpal floor may have

different levels

If cavity margins are located in occlusal 1/3 of inclined planes of cusps, the buccal and lingual walls will have two planes

DESIGN 3LOCATION:Occlusal one- to two-thirds of facial and lingual surfaces of molars & lingual surfaces of anterior teeth

INDICATIONS:• the pit or fissure is decayed• used to eradicate pit or fissure as a prophylactic measure• involved pit is not connected w/ other surface(s) or lesions in the tooth• for invaginated teeth

GENERAL SHAPE: rounded, triangular, oblong, etc.INTERNAL ANATOMY: • All walls are joined together in a seemingly continuous fashion• Axial wall should be flat & make a definite acute angle with the continuous surrounding wall• If it is not conforming to enamel rod direction, it should be made in two planes

DESIGN 4LOCATION:Occlusal surfaces of molars and grooved part of their facial/lingual surface

INDICATIONS:• caries lesions at facial/lingual pits are connected to the occlusal surface• decay undermines facial/lingual marginal ridges• caries cones confined to the concavity of their grooves• cusps not undermined by backward decay

GENERAL SHAPE:same with design 1 & 2 facial/lingual part - parallelogram

INTERNAL ANATOMY

Mesio-distal cross-section

Bucco-lingual cross-section

DESIGN 5

LOCATION:Occlusal and facial and/or lingual surfaces of molars

INDICATIONS:• facial/lingual cusps undermined by backward decay• outline is not conducive to retention of restoration• caries cones in dentin exceed 1 mm from DEJ• foundation for cast restoration is needed

GENERAL SHAPE:same with design 2 facial/lingual part – parallelogram (larger)

INTERNAL ANATOMY

Mesio-distal cross-section

Bucco-lingual cross-section

DESIGN 6

LOCATION:Occlusal surfaces of molars & premolars as well as portion of facial, proximal or lingual surface in the form of a “table” of an entire cusp or a section of a cusp

INDICATIONS:• Portions or an entire cusp undermined by backward decay• caries leaves a cusp with a length-width ratio of 3:1 in functional cusp or 4:1 in non-functional cusp, and there is no interruption in the continuity of surrounding walls• caries leaves a cusp with a length-width ratio of 3:1 in functional cusp or 4:1 in non-functional cusp, and there is interruption in the continuity of surrounding walls• marginal ridge is crossed by a fissure to facial/lingual embrasures• foundation for a future cast restoration is needed• Class I occlusal lesion is continuous with a Class VI lesion

DESIGN 7

LOCATION:Occlusal, facial, and/or lingual surfaces of molars & premolars

INDICATIONS:• class 1 lesions with extensive carious involvement• Placement of internal boxes in the floor of preparation is impossible.• Pin/Post-Retained Restoration

DESIGN 8

LOCATION:Occlusal surfaces of molars & premolars, sometimes lingual surface of anterior teeth

INDICATIONS:• for endodontically treated teeth

FOR AMALGAM

CAVITY PREPARATIONs

1 2 3 4 5