3. • STAINLESS STEEL CROWN:
Stainless steel (preformed) crowns are
prefabricated crown forms, which can be
adapted to individual primary molars and
cemented in place to provide a definitive
restoration. They are considered the most
durable and reliable restoration.
3
5. Indications:
Stainless steel crowns are the restoration of
choice in the following situations:
1. Restoration of primary or permanent teeth with
extensive carious lesions (more than two
surfaces affected).
2. Following pulpotomy or pulpectomy
procedures (teeth become brittle after removal
of pulp content and may fracture if not
protected).5
7. 3. Restoration of teeth affected by
developmental problems (e.g. enamel
hypoplasia, amelogenesis and dentinogenesis
imperfecta).
4. As an abutment for certain appliances, such as
space maintainers.
5. In patients with high caries susceptibility or
where routine oral hygiene measures cannot
be performed (handicapped patients).
7
10. Clinical procedures:
Appropriate local analgesia should be
obtained and the tooth should be isolated,
preferably with rubber dam.
Caries removal and appropriate pulp
treatment should be completed if necessary.
10
11. Tooth preparation:
Approximal reduction to open the contact
using tapered diamond stone.
Occlusal reduction (l – 1.5 mm) to avoid
occlusal prematurity using wheel stone.
Buccal and lingual preparation is not always
necessary except where there is a large buccal
bulge.
The preparation should finish with a smooth
feather edge cervically with no step or
shoulder.11
12. Crown selection:
The selected crown must fit to the prepared
tooth with a tight snap.
Choosing the correct size is assisted by
measuring the mesiodistal dimension of the
tooth using a divider.
12
15. Crown adaptation:
Try the crown on the tooth, place the crown on
the lingual side and rotate it toward the buccal
side. The crown should extend 1mm beneath
the gingiva.
Most commercially available crowns are
anatomically trimmed and contoured cervically
and require little or no modification.
If the gingival extension is too long, using a
crown and bridge scissors cut around the
gingival margin of the crown/then contour it
with a ball and socket plier.
15
19. Crown cementation:
The status of the pulp influence selection of
the cementing material. A cavity varnish must be
applied before cementing a crown to a vital
tooth. There are several options for the
cementing media e.g. zinc phosphate cement,
zinc oxide eugenol cement, re-inforced zinc
oxide eugenol cement, polycarboxylate cement
and glass ionomer cement. Zinc phosphate
cement is commonly used for cementation of
stainless steel crowns.
19
20. Causes of stainless steel crown failures:
1. Poor tooth preparation.
2. Poor crown adaptation and subsequent poor
retention.
3. Improper cementation and presence of open
margins.
4. Recurrent caries.
5. Crown abrasion through the occlusal surface.
20
21. Recent advances:
Stainless steel crowns may be esthetically
improved by placement of composite resin in a
buccal window cut into the labial face of the
crown.
Crowns with prefabricated tooth colored
buccal facings are available.
Crown forms with bonded resin veneers for
primary incisors were developed to serve as a
convenient, durable, reliable and esthetic
solution for restoring severely destructed
primary incisors.21
25. • The general principle of oral surgery remains the
same whether applied to the adults or to children.
However, in the child we are dealing with a
developing organism in both its physical and its
psychological aspects. Techniques, therefore,
must be modified to conform to the needs of this
growing patient. Some factors to be considered in
oral surgery for children as compared to adults
are:
25
26. 1. The oral cavity is small and there is greater
difficulty in gaining access to the field of
operation.
2. The jaws are in the process of growth and
development and the dentition is in a
continuous state of change with eruption and
resorption of primary teeth and eruption of
permanent teeth taking place simultaneously.
Any interference with growth centers in the
jaws or premature extraction of primary teeth
may lead to malformations of the jaws, the
permanent teeth or both.
26
29. 3. The bone structure of a child contains higher
percentage of organic material, which makes
it more liable than adult bone and not as
likely to fracture.
29
30. Extraction of teeth:
Indications for extraction of primary teeth:
1. Teeth decayed beyond possible repair, when
caries reach down into the furcation or if
sound gingival margin cannot be established.
2. Infection of the periapical or inter-radicular
area and cannot be eradicated by other means.
3. Case of acute dento - alveolar abscess with
cellulitis.
4. Teeth interfering with normal eruption of
succeeding permanent teeth.
5. Submerged teeth.30
33. Contraindications to extraction of primary
teeth:
Many of these contraindications are relative
and may be overcome with special precautions
and premedication:
1. Acute infectious stomatitis, acute ulcerative
gingivitis or gingivostomatitis, acute herpetic
stomatitis. The acute phase should be
controlled before extraction.
33
34. 2. Blood dyscrasia: These render the patient
susceptible to postoperative infection and
hemorrhage. Extractions should be performed
only after consultation with hematologist and
proper preparation of the patient.
3. Rheumatic heart disease, congenital heart
disease and congenital kidney disease require
proper antibiotic coverage.
34
35. 4. Acute systemic infections of childhood,
because of lowered body resistance.
5. Malignancy, if suspected, on the other hand,
extractions is strongly indicated if the orofacial
areas are to receive irradiation.
6. Teeth which have remained in irradiated bone.
7. Diabetes mellitus: a relative contra-indication.
After proper medical consultation to make
certain that, the child is under control.
35