1. INTRODUCTION
& Extra-coronal
TERMINOLOGY restorations
Part I: General Partial
considerations coverage
restorations

2.  Partial coverage restorations
as we said before, these are restorations
that used to restore just a portion of the
clinical crown.
And are classified according to retention,
as:
1. by grooves : ¾, R3/4, ½, 7/8
crowns (= restorations).
2. by pins (pin-ledge).
3. Modified type (grooves + pins).

3. ¾ crown :
is a partial coverage restoration that restores
the occlusal surface(or incisal edge), and three
axial surface of the clinical crown (the facial or
buccal surface is not included).
this type is indicated for upper anterior and
posterior teeth.
and it can be prepared on a lower posterior
teeth too with little difference in the
preparation.

4.  Reversed ¾ crown :
is a partial coverage restoration that
restores the occlusal surface(or incisal
edge), and three axial surface of the
clinical crown (the lingual surface is not
included).
this type is indicated for lower
posterior teeth. And it is useful for server
lingual indications.

5.  Mesial ½ crown :
is a partial coverage restoration
that restores the occlusal surface(or
incisal edge), the mesial surface and
a portion of the facial or lingual
surfaces.
this type is indicated for mesially tilted
tooth.

6.  7/8 crown :
is a partial coverage restoration that
restores the all surfaces of the clinical
crown except the mesiobuccal cusp
remains intact.
this type used only for the maxillary
first molar teeth.

7.  Pin-ledge
is a technique that employs parallel long
pins prepared in the lingual or palatal surface
of the clinical crown,
in order to increase retention
of the restoration.

8. These restorations used the
both grooves and pins to
improve retention.

9. Partial coverage
restorations •Indications
the partial coverage restorations are used:
1. for both anterior and posterior teeth.
2. when the coronal portion is intact.
3. when there is a good crown length.
4. as a retainer for FPD (short edentulous
span).
5. when there is a minimum occlusal stress.

10. Partial coverage • Contraindications
restorations
the partial coverage restorations are
contraindicated :
1. when maximum retention is required.
2. in case of a thin or short clinical crown.
3. for patient with high caries index.
4. when there is active periodontal disease.
5. in case of mal formed tooth, e.g. Bell
shaped canine.

11. Partial coverage • Advantages
restorations
1. preservation of tooth structure.
2. more esthetic than full coverage
restorations.
3. the finish line is easy to place.
4. less periodontal irritation due to the
less contact with the tissues.
5. pulp damaged is reduced.

12. Partial coverage • Disadvantages
restorations
1. less retentive than the full coverage.
2. difficultly of placing the grooves and
pins properly.
3. in some restorations, the metal is
displayed and this is not acceptable by
the patient.

13. The ¾ crown is :
a. a restoration that restores the all
surfaces of the clinical crown except the
mesiobuccal cusp remains intact.
b. a technique that employs parallel long
pins prepared in the lingual or palatal
surface of the clinical crown.
c. a restoration that restores the occlusal surface and
three axial surface of the clinical crown without
including the buccal surface in the preparation.
* In which cases, the partial coverage restorations
are contraindicated?