General principles and designs of cavity preparation for Class I caries. By Ma. Hermie Culeen Barapon

1. CLASS 1 CAVITY PREPARATION
Placedinpits andfissure lesions thatoccurinoneor moreof theff:
a. Occlusalsurfacesof molarsandpremolars
b. Occlusal2/3of buccalandlingualsurfaces ofmolars
c. Lingualsurfacesof anterior teeth
d. Anyother unusuallylocatedpit or fissure involved with decay

2. COMMON FEATURES
Outline form consists of smooth curves
that avoid occlusal eminenceslikecusps
and ridges
Uniformdepth of 1.5-2mmfrom CSM
Or 0.5-1mm from theDEJ
Proximal walls are perpendicularto the pulpal
floor or diverge pulpo-occlusaly
Proximal walls located 1.6-2mm from the
proximal surface
Roundinternal lineangles
Buccal and lingual walls converge pulpo-
occlusally
Butt joint or 90˚CSM
Proximal walls follow contourof
proximal surface
Pulpal floor is flat and usually
perpendicular to the long axis of the
tooth

3. DESIGN 1
PROCEDURE
Bucco-lingualcross-section Mesio-distalcross-section
InternalAnatomy

4. DESIGN 1
Maxillarypremolar
“dumb-bell”-shaped
Mandibular 1st premolar
Circular,resembling snake
eyes
Mandibular 1st premolar
“dumb-bell”-shaped
Mandibular 2ndpremolar
Y-shaped
Mandibular 1st molar
Elongated
Mandibular 2ndmolar
Elongated
Maxillarymolar
Elongated
Maxillarymolar
Mesial “kidney” shaped
Distal “heart” shaped
LOCATION:
Occlusal surfaces of
molars & premolars
INDICATIONS:
•caries penetration into
dentin does not exceed
0.5mm-1mm
•involvement of
enamel or pits and
fissures will not widen
more than ¼intercuspal
distance
•good oral hygiene&
low caries index
•Areas of mouthwith
low cariogenic activity

5. DESIGN 2
LOCATION:
Occlusal surfaces of
molars & premolars
INDICATIONS:
•caries cone in dentin
extend 1 mmor more
from DEJ
•preparation
involvement is more
than ¼ ICD
•as preventive measure
inpatients with high
plaque &caries index
•for teeth with intact
cusps
Shapes similar to design 1 but thereare
more deviations from shapes and less
curvedoutlineand greater surface
dimensions
Margins similar to design 1 but
closer to cusp tips and crests of
ridges
Bucco-lingualcross-section
Pulpal floor may have
different levels
If cavity margins are
located in occlusal 1/3of
inclined planes of cusps,
the buccal and lingualwalls
will havetwo planes

6. DESIGN 3
LOCATION:
Occlusal one-to two-thirds of
facial and lingual surfaces of
molars & lingual surfaces of
anterior teeth
INDICATIONS:
•the pit orfissure is decayed
•used to eradicate pit or
fissure as a prophylactic
measure
•involved pit is not
connected w/ other surface(s)
or lesions inthe tooth
•for invaginated teeth
GENERALSHAPE: rounded, triangular,oblong, etc.
INTERNALANATOMY:
•All walls are joined together in a seemingly continuous fashion
•Axial wall should be flat &makea definite acuteangle with the continuous
surroundingwall
•If it is not conformingto enamelrod direction, it should bemade intwo planes

7. DESIGN 4
LOCATION:
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
•cariescones confined to
the concavity of their
grooves
•cusps not underminedby
backward decay
GENERALSHAPE:
same with design 1 &2
facial/lingual part -parallelogram
INTERNALANATOMY
Mesio-distal cross-section
Bucco-lingualcross-section

8. DESIGN 5
LOCATION:
Occlusal and facial and/or
lingual surfaces of molars
INDICATIONS:
•facial/lingual cusps
underminedby backward
decay
•outline is not conducive
to retention of restoration
•caries cones in dentin
exceed 1 mmfrom DEJ
•foundation for cast
restoration is needed
GENERALSHAPE:
same with design 2
facial/lingual part – parallelogram (larger)
INTERNALANATOMY
Mesio-distal cross-section
Bucco-lingualcross-section

9. DESIGN 6
LOCATION:
Occlusal surfaces of molars &premolars as well as portion of facial, proximal or lingualsurface in theform of a “table” of
an entirecusp ora section of a cusp
INDICATIONS:
•Portions or an entirecusp underminedby backward decay
•cariesleaves a cusp with a length-width ratio of 3:1infunctional cuspor 4:1innon-functionalcusp, and thereis no
interruption in the continuityof surroundingwalls
•caries leaves a cusp with a length-width ratio of 3:1 infunctional cusp or 4:1 innon-functionalcusp, and there is
interruption in the continuityof surroundingwalls
•marginalridge is crossed by a fissure to facial/lingual embrasures
•foundation for a futurecast restoration is needed
•Class I occlusal lesion is continuous with a Class VIlesion

10. DESIGN 7
LOCATION:
Occlusal, facial,and/orlingual surfacesof molars& premolars
INDICATIONS:
•class1lesions withextensivecariousinvolvement
•Placementof internalboxesin thefloorofpreparationis
impossible.
•Pin/Post-RetainedRestoration

11. DESIGN 8
LOCATION:
Occlusal surfaces of molars &premolars, sometimes lingualsurface of anterior teeth
INDICATIONS:
•for endodontically treated teeth

12. FOR AMALGAM
CAVITYPREPARATIONs