class v [lecture by dr.wedad etman @amcofam]

8/6/2019 Class V [Lecture by Dr.Wedad Etman @AmCoFam]

1/15


2/15

Smooth surface lesions

Located on the gingival third of

labial, buccal & lingual surfaces of

all teeth


3/15

CARIES may not be the only reasonCARIES may not be the only reasonCARIES may not be the only reasonCARIES may not be the only reason

Causative factor

Abrasion , Erosion & AbfractionAbrasion , Erosion & AbfractionAbrasion , Erosion & AbfractionAbrasion , Erosion & Abfraction couldcouldcouldcould

ALSO be responsible for class V lesionsALSO be responsible for class V lesionsALSO be responsible for class V lesionsALSO be responsible for class V lesions


4/15

1111.... The carious lesion usually starts as aThe carious lesion usually starts as aThe carious lesion usually starts as aThe carious lesion usually starts as awhite or chalky line at the gingivalwhite or chalky line at the gingivalwhite or chalky line at the gingivalwhite or chalky line at the gingival 1111////3333 ofofofof

clinical characteristics

2222.... Usually affects multiple teethUsually affects multiple teethUsually affects multiple teethUsually affects multiple teeth( high caries susceptibility )( high caries susceptibility )( high caries susceptibility )( high caries susceptibility )


5/15

3333.... Spread mesially & distally to the axialSpread mesially & distally to the axialSpread mesially & distally to the axialSpread mesially & distally to the axial

angles of teethangles of teethangles of teethangles of teeth4444.... Causes Cervical sensitivityCauses Cervical sensitivityCauses Cervical sensitivityCauses Cervical sensitivity

5555.... e more convex is t e sur acee more convex is t e sur acee more convex is t e sur acee more convex is t e sur acemore liable tomore liable tomore liable tomore liable to

cervical cariescervical cariescervical cariescervical caries6666. More frequent among old. More frequent among old. More frequent among old. More frequent among old----aged patientsaged patientsaged patientsaged patients

(senile caries)(senile caries)(senile caries)(senile caries)


6/15

The Outline Form

Class V cavity usuallyClass V cavity usuallyClass V cavity usuallyClass V cavity usually

TrapezoidalTrapezoidalTrapezoidalTrapezoidal outlineoutlineoutlineoutline withwithwithwith straightstraightstraightstraight

with thewith thewith thewith the short armshort armshort armshort arm being thebeing thebeing thebeing thegingivalgingivalgingivalgingival


7/15

Mesial & distal walls

extended to but not encroaching onaxial line angles & Parallel to the M &

Location of marginsLocation of marginsLocation of marginsLocation of margins


8/15

Occlusal wall located at but notincluding the height of contour

Gingival wall straight & parallel toocclusal plane at the gum margin


9/15

Axial wall in dentin (0.5 mmunder DEJ)

convex outwards Mesiodistally &occlusogingival following contour offacial surface

provides resistance

& maximal pulpprotection protection


10/15

Internal anatomy M & D walls are divergent outwards

(flare mesially & distally )..tofollow the direction of enamel rods -

provide strength for the tooth & amalgam & prevent undermined enamel walls


11/15

Occlusal & gingival walls formedof 2 planes:

a. Grooved internal dentin plane(mechanical retention lock)

Internal anatomyInternal anatomyInternal anatomyInternal anatomy

. uter ename p ane o ow ngthe direction of enamel rods

To form 9090 cavo-surfaceangle ..resistance


12/15

Gingival depth ....- mm

Occlusal wall is.-. mm

Slightly deeper at the occlusalwall where there is thicker

enamel


13/15

If the gingival wall is located on

cementum at the root, it is alsoformed of two planes

of dentin &

* an outer flat plane made ofdentin & cementum


14/15

Resistance and

Retention

It is not subjected to a direct

functional loading Definite line & point angles

Walls to the floorA minimum dept ofA minimum dept ofA minimum dept ofA minimum dept of00000000........55555555 mmmmmmmmmmmmmmmm in dentinin dentinin dentinin dentin

uniform bulk of amalgamuniform bulk of amalgamuniform bulk of amalgamuniform bulk of amalgam Grooves

pins


15/15

Enamel hatchet or wedelstadetchisel

are used to finish the Enamel marginsto provide a

cavo-surface angle

class v [lecture by dr.wedad etman @amcofam]

Documents