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Cavity preparation class 1

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Page 1: 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

Page 2: Cavity preparation class 1

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

Page 3: Cavity preparation class 1

DESIGN 1

PROCEDURE

Bucco-lingual cross-section

Mesio-distal cross-sectionInternal

Anatomy

Page 4: Cavity preparation class 1

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

Page 5: Cavity preparation class 1

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

Page 6: Cavity preparation class 1

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

Page 7: Cavity preparation class 1

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

Page 8: Cavity preparation class 1

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

Page 9: Cavity preparation class 1

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

Page 10: Cavity preparation class 1

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

Page 11: Cavity preparation class 1

DESIGN 8

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

INDICATIONS:• for endodontically treated teeth

Page 12: Cavity preparation class 1

FOR AMALGAM

CAVITY PREPARATIONs

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