Class III Caries Lesion

• Proximal contact of anterior teeth• Begins at ginigval edge of contact area• Requires higher risk than pit & fissure caries

Mandibular incisor

Maxillarylateral inciso

Maxillary canine

cavitated lesion at contact area

Class III Preparation Features

• Labial or Lingual Access

caries lesion

contact area

#9-M Class III cavity preparation

lingual-approach

#9-M Class III cavity preparation

lingual-approach

Lingual access outline form best esthetics

#9-M Class III cavity preparation

lingual-approach

Labial access outline formpreserves marginal ridges

Class III Preparation Features

• Labial or Lingual Access• Outline Form: Lesion-Specific• Extension: Incisal wall still in contact• Proximal Depth & I-G Dimension prescribed

3 mm

1.0-1.25 mm

Class III Preparation Features

• Labial or Lingual Access• Outline Form: Lesion-Specific• Extension: Incisal wall still in contact• Proximal Depth & I-G Dimension prescribed• Walls: smooth• Internal Line Angles: rounded, no retentive features• Cavosurface Margins: crisp, smooth, free of loose enamel

#245 bur

enamel lip

Class III Preparation Features

• Labial or Lingual Access• Outline Form: Lesion-Specific• Extension: Incisal wall still in contact• Proximal Depth & I-G Dimension prescribed• Walls: smooth• Internal Line Angles: rounded, no retentive features• Cavosurface Margins: crisp, smooth, free of loose enamel• Cavosurface Bevel

bevel fades out

continuous bevel

bevel fades out

Purpose of Bevel:

• better etch pattern

• increases enamel surface area being bonded

• increases overall retention

• improves marginal seal

• eases shade transition

Class III Preparation Features

• Labial or Lingual Access• Outline Form: Lesion-Specific• Extension: Incisal wall still in contact• Proximal Depth & I-G Dimension prescribed• Walls: smooth• Internal Line Angles: rounded, no retentive features• Cavosurface Margins: crisp, smooth, free of loose enamel• Cavosurface Bevel• Cleanliness: free of debris, uncontaminated by saliva or blood

Isolate from #5 to #12Isolate from #5 to #12

#8-D

Shaft of bur shouldnot be parallel toproximal plane

#2 round burhigh speed

Access throughlabial embrasure

Center on gingival edge of contact area

#2 round bur: head diameter 1.0 mm

Rounded box form 3 mm I-G X 1-1.25 mm M-D

Access through labial embrasure

Extend lingually until contact broken

ProximalContact

Area

Gingival

Labial wa

Axial wal

Lingual w

Incisal wa

Lingual contact broken

Error?

Incisal contact broken

Lingual still in contact

Error?

Error?

Centered on contact

Incisal contact broken

Error?

111 Hoe

#7902Needle finishing bur

0.5-1.0 mm bevel 20-45

#9-M Lingual Approach#9-M Lingual Approach

NoNo

YeYe

Jeffery 7Jeffery 7(Jeffery 7 LH)(Jeffery 7 LH)

79027902Needle finishing burNeedle finishing bur

9-M(Li)9-M(Li)

9-M(Li)9-M(Li)8-D(F)8-D(F)

#10-D Lingual Approach#10-D Lingual Approach NoNo

YeYe

NoNo

YeYe

Error?

Facial contact

Error?

Error?

Unsupported enamel

Error?

Error?

Centered on contact

Error?

Error?

No gingival wall

Error?

Error?

No incisal contact

Error?