CLINICAL PEDIATRIC DENTISTRY I DSV 441

CHAPTER 18 RESTORATIVE DENTISTRY

(364-387) STAINLESS STEEL CROWNS FOR POSTERIOR TEETH

McDonald, Avery, Dean. Dentistry For The Child

And Adolescent, 8th Ed.

23

Tuesday 7\42015

1:00 pm-2:00 pm

OTHMAN AL-AJLOUNI 1

LECTURE OUTLINE

PREPARATION OF THE TOOTH

SELECTION OF CROWN SIZE

CONTOURING OF THE CROWN (When

Necessary)

2

LEARNER OBJECTIVES

At the end of the lecture student should know

How to do preparation for SSC

How to select SSC

How to fit and cement SSC

3

S T A I N L E S S S T E E L C R O W N S F O R P O S T E R I O R T E E T H

Chrome steel crowns, as introduced by Humphrey in 1950, have

proved to be serviceable restorations for children and adolescents

and are now commonly called stainless steel crowns. There are a

number of indications:

1. Restorations for primary or young permanent teeth with

extensive and/or multiple carious lesions

2. Restorations for hypoplastic primary or permanent teeth that

cannot be adequately restored with bonded restorations

3. Restorations for teeth with hereditary anomalies, such as

dentinogenesis imperfecta or amelogenesis imperfecta

4. Restorations for pulpotomized or pulpectomized primary or

young permanent teeth when increased danger of fracture of

remaining coronal tooth structure

5. Restorations for fractured teeth

6. Restorations for primary teeth to be used as abutments for

appliances

7. Attachments for habit-breaking and orthodontic appliances 4

S T A I N L E S S S T E E L C R O W N S F O R

P O S T E R I O R T E E T H Randall compared performance of crown restorations with that of

multisurface amalgam restorations. Crown restorations were

superior to amalgam restorations in treatment of multisurface

cavities in primary molars.

Especially in children at high risk for caries.

Stainless steel crown (SSC) is an extremely durable restoration....

Children with extensive decay, large lesions or multiple surface

lesions in primary molars should be treated with SSC.

Because of protection from future decay provided by their feature

of full coverage and their increased durability and longevity, strong

consideration should be given to use of SSCs in children who

require general anesthesia.

Finally, a strong argument for use of SSC restoration is its cost

effectiveness based on its durability and longevity. 5

PREPARATION OF THE TOOTH

LA administered and a rubber dam placed.

Proximal surfaces are reduced using a No. 69L

bur at high speed. Care must be taken not to

damage adjacent tooth surfaces.

Wooden wedge placed tightly to provide a slight

separation for better access.

Near-vertical reductions are made on the

proximal surfaces and carried gingivally until

the contact with the adjacent tooth is broken and

an explorer can be passed freely between the

prepared tooth and the adjacent tooth.

Gingival margin of the preparation on proximal

surface should be a smooth feathered edge with

no ledge or shoulder present. 6

PREPARATION OF THE TOOTH Cusps and occlusal portion be reduced with a

No. 69L bur revolving at high speed. The

general contour of occlusal surface is followed,

and approximately 1 mm of clearance with the

opposing teeth is required.

The No. 69L bur at high speed used to remove

all sharp line and point angles.

It is usually not necessary to reduce buccal or

lingual surfaces; in fact, it is desirable to have an

undercut on these surfaces to aid in retention of

contoured crown. In some cases, however, it

may be necessary to reduce distinct buccal

bulge, particularly on first primary molar.

If any carious dentin remains after these steps in

crown preparation are completed, it is excavated

next. 7

SELECTION OF CROWN SIZE The smallest crown that completely covers

preparation should be chosen. Spedding

has advocated adhering to two important

principles that will help consistently to

produce well-adapted stainless steel

crowns. First, operator must establish

correct occlusogingival crown length; and

second, crown margins should be shaped

circumferentially to follow natural

contours of tooth's marginal gingivae. The

crown should be reduced in height, if

necessary, until it clears occlusion and is

approximately 0.5 to 1 mm beneath free

margin of gingival tissue.. 8

SELECTION OF CROWN SIZE Patient can force crown over preparation by

biting an orangewood stick or a tongue

depressor. After making a scratch mark on

crown at level of free margin of gingival

tissue, dentist can remove crown and

determine where additional metal must be

cut away with a No. IIB curved shears or a

rotating stone. With a curved-beak pliers, cut

edges of crown are redirected cervically and

crown is replaced on preparation. Child is

again directed to bite on an orangewood

stick to forcibly seat crown so that gingival

margins may be checked for proper

extension. The precontoured and festooned

crowns currently available often require very

little, if any, modification before

cementation. 9

CONTOURING OF THE CROWN (WHEN

NECESSARY)

A crown-contouring pliers with a ball-

and-socket design is used at cervical

third (if loosely fitting, start at middle

third) of buccal and lingual surfaces to

help adapt margins of crown to

cervical portion of tooth. The handles

of pliers are tipped toward center of

crown, so that metal is stretched and

curled inward as crown is moved

toward pliers from opposite side. A

curved-beak pliers is used to further

improve contour on buccal and lingual

surfaces. 10

CONTOURING OF THE CROWN (WHEN NECESSARY)

The curved-beak pliers used to contour proximal

areas of crown and develop desirable contact

with adjacent teeth. Many clinicians prefer to

complete crown contouring procedures with a

crown-crimping pliers. If necessary, solder may

be added to proximal surfaces of crown to

improve proximal contacts and contour.

Trimming and contouring are continued until the

crown fits preparation snugly and extends under

free margin of gingival tissue. Crown should be

replaced on preparation after contouring

procedure to see that it snaps securely into place.

Occlusion should be checked at this stage to

make sure that crown is not opening bite or

causing a shifting of mandible into an

undesirable relationship with the opposing teeth. 11

CONTOURING OF THE CROWN (WHEN NECESSARY)

The final step before cementation is

to produce a beveled gingival margin

that may be polished and that will be

well tolerated by gingival tissue. A

rubber abrasive wheel can be used to

produce smooth margin. On

occasion best-fitting crown may

need to be modified to produce a

more desirable adaptation to

prepared cervical margin. The

oversized crown may be cut and the

cut edges overlapped. 12

CONTOURING OF THE CROWN (WHEN

NECESSARY) The crown is removed from tooth and overlapped

material repositioned and welded. A small amount of

solder is flowed over outside margin. Crown is finished in

previously recommended manner and cemented to

prepared tooth.

If tooth is too large for largest crown, a similar technique

may be helpful. Crown cut on buccal or lingual surface.

After crown has been adapted to prepared tooth, an

additional piece of 0.004-inch stainless steel band

material may be welded into place. A small amount of

solder should be added to outer surface of margins.

Crown may then be contoured in usual manner, polished,

and cemented into place. 13

Sunday, April 05, 2015 Professor Othman Al-Ajlouni 14

Pre- Operative: Post- Operative:

Sunday, April 05, 2015 Professor Othman Al-Ajlouni 15

THANK YOU