A smile isthe first thing

we notice when we greet someone. If that person does-

n’t smile back, then we become concerned or even wary.

But some people don’t smile because their teeth are dis-

colored, crooked, chipped or missing, and they want to

hide the defects.

As our patients, we know that they want a beautiful

smile. But the dentist also must be concerned with creat-

ing a fully functional restoration. Fortunately, tremendous

advances in esthetic dentistry allow us to provide patients

with an opportunity to achieve both functionality and an

esthetics. Here’s the story one such woman and how the

dental team restored her smile and her confidence.

CASE HISTORYA woman patient in her 40s was exposed to Tetracy-

cline in early childhood, resulting in intrinsic tooth

staining (Fig. 1). The chemical reaction to the Tetra-

cycline eroded 1.5 mm on the lingual of her maxillary

anterior (Fig. 2) and severely discolored the facials. In

addition, there was excessive wear of the anterior incisal

edges.

While the patient was extremely interested in alter-

ing the discoloration and shape of her teeth, the den-

tist’s primary concern was establishing functional

occlusion to provide longevity to the restorations and

her smile (Fig. 3).

Full crown restorations would ensure uniform

protrusive guidance to reestablish her bite and pro-

vide sustainable oral health, while creating white, uni-

form-looking teeth. Because the patient’s gingival

tissue was receding, a subgingival margin on the restora-

tions would leave some room for additional gingival

movement without producing new discoloration. The

patient wanted only to treat the maxillary anterior and

would consider restorations on the mandible at a later

time (Fig. 4).

6

PREDICTABLE &FUNCTIONALANTERIORCROWNS

6

PREDICTABLE

&FUNCTIONAL

ANTERIOR

CROWNSBy Luke S. Kahng, CDT, MDT

Dentistry by Dr. David Bork

By Luke S. Kahng, CDT, MDT

34 dentallabproducts SEPTEMBER 2006

FORWARDTrendsCATEGORY \\\\

Layout OK 1st edit 2nd edit 3rd edit Final edit Ad Production

Tetracycline exposure in early childhood resulted in intrinsictooth staining.

Maxillary anterior lingual occlusion shows bulemia-type wear ofthe enamel.

www.dentalproducts.net

1

2

The problem

LUKE S. KAHNGCDT, MDTFounder/Owner, CapitalDental Technology Laboratory

Specializing in fixed restorations,Kahng provides personalizedcustom cosmetic work. Hestresses education,communication, and a teamapproach to patient care.

36 dentallabproducts SEPTEMBER 2006

Layout OK 1st edit 2nd edit 3rd edit Final edit Ad Production

TREATMENT PLANThe dentist elected to use the LSK 121 Treatment Plan

Wax-up that I developed to ensure the dental team could

have a blueprint for the desired outcome and keep all

parties are on the same page. The Treatment Plan Wax-

up is used to establish occlusion (Figs. 5 and 6), centric

stops, a smile line, improved esthetics as well as provide

tooth reduction requirements and pre-plan gingival tis-

sue re-contouring if needed.

Not only is the wax-up an important element of the

treatment plan, but also increases case acceptance.

By allowing the patient to view the intended results as

an accurate 3-D model, the doctor can better explain

the treatment procedures, and the patient feels con-

fident that the restorations will appeal to her esthetic

requirements. The wax-up further serves as a template

for the doctor and as a communication tool for the

laboratory.

The wax-up included reductions for proper occlusion

(Fig. 7), protrusive guidance (Fig. 8), canine rise (Figs.

9 and 10), lengthening the centrals (Fig. 11), lingual mor-

phology with centric stops (Figs. 12 and 13), and lip sup-

port (Fig. 14). Once the patient approved the final

look of the restorations, a silicone index was created

using the wax-up. The silicone index also would be used

as for creating the temporaries and preparations.

CLINICAL PROCEDUREThe teeth were prepped with rounded edge shoulder

margins (Fig. 15). This preparation conforms to all-

ceramic preparation guidelines that call for maintain-

ing 1.2 mm of circumferential room with 1.5 mm at the

incisal and no sharp angles. A polyvinyl siloxane impres-

sion and final bite registrations were taken. The bite

registration consisted of two centric bites and one pro-

trusive bite.

The silicone index made from the LSK 121 Treatment

Plan Wax-up was used as a matrix for the temporaries.

The patient examined the temporaries to see if any adjust-

ments were needed and communicated those changes

to the dentist. The dentist can change the length or shape

of the restorations by communicating with the techni-

cian on the modifications or take an impression of the

temporaries and have a new study model created reflect-

ing the changes.

The dentist and dental technician generated the shade

mapping. The patient wanted to change her discolored

teeth to a light color. A bleach shade was selected. By

combined layering of other colors, a natural-looking

appearance would be achieved.

LABORATORY PROCEDUREThe LSK 121 Treatment Plan Wax-up was fabricated to

The opposing cast marks the incisors that need reduction forproper occlusion.

Lateral excursion view shos patient’s central and lateral move-ment.

Canine rise view shows that the central and lateral slightlytouch.

Canine rise on the other side will need to adjust for clearance.

LSK Treatment Plan wax-up checks the height of contour.Incisors must be increased by 2mm.

View of lingual morphology and the centric stop.

Occlusal view of the centric stop shows that the midline isslightly off.

Left side view of the waxup with lengthened centrals that alsowere brought out facially.

Phot

o co

urte

sy o

f XX

X

FORWARDTrends \\\\CATEGORY

www.dentalproducts.net

Initial view reveals the edge-to-edge incisors need tooth length-ening.

Crooked teeth on the mandible shown in this occlusal view willaffect the bite.

Edge-to-edge view shows incisal edges and lack of canine rise. The premolar and canine rise illustrates the need to lengthenincisors for proper occlusion.

3 4

5 6

7 8

9 10

11 12

13 14

The problem

The LSK treatment

“The immediate resultfrom the patient was

a long-awaited, joyous smile.”

show the esthetic outcome and to confirm the resulting

function of the anterior teeth. Based upon the intended

height of contour, the incisors would be lengthened

by 2 mm. When examining lateral excursion, canine rise,

and other movements, it was discovered that the mandible

anterior also would require adjustment; the opposing

mandible model was adjusted and marked for the doc-

tor to create the anatomic form of the restoration and

the occlusal morphology.

The laboratory selected Procera zirconia for the under-

structure because of its benefits: Procera zirconia is

known for its proven strength, biocompatibility, and

esthetic results. While all-ceramic restorations have a

higher translucency that shines through to the surface,

the zirconium’s opacity blocks out discoloration while

possessing the benefits of ceramic restorations.

The technician uses the framework to fabricate the

restoration with multi-layered porcelain powders and

applied porcelain color build-up. The process involves

applying different colors of porcelain powders (Fig 16)

onto the crown to bring out the true understructure and

generate a warm color that creates a natural, healthy-

looking restoration. Without this multi-layering tech-

nique, the tooth color would look flat.

The surface texture (Fig 17) is important to further

accentuate the natural look of the teeth by influencing

what the multi-layered buildup and understructure will

look like from different angles.

After completion of the restorations, the dental tech-

nician verified that they met all the necessary functional

values such as confirming the correct lingual morphol-

ogy and tooth movements, which create the thickness

of the incisal edge. The crowns (Fig. 18) were then

sent back to the dental office for insertion.

CEMENTATIONThe temporaries were removed and the crowns tried in

for the patient to approve. The Procera zirconia is treated

like a normal crown. It blocked out the discolored prepa-

ration and, while it is technically not a bond, it provided

surface roughness that allowed for exceptional cemen-

tation strength without requiring special techniques or

special cements. The restorations (Fig. 19) were then

seated, ensuring proper proximal contact. Once the

cement set, the excess was gently removed from the mar-

gins. The immediate result from the patient was a long-

awaited, joyous smile. After seeing her new teeth, the

patient decided that she also wanted her mandibular

anteriors completed. Beyond the esthetic outcome,

the patient will appreciate the long-term functionality

and longevity of the restoration. Her centric (Fig. 20) and

lateral excursion (Fig. 21) needed slight adjustments. The

laws of predictability (Fig. 22) were followed with an

emergence profile, tooth long axis, three-dimensional

guideline, color, surface texture, avoided black trian-

gle, incisal silhouette, and lip support. The canine rise

(Fig. 23) will be further improved once her mandible

teeth are completed.

CONCLUSIONThe patient may have been hesitant to smile when

she first came to the dental office, but upon leaving, she

was smiling (Fig. 24) from ear to ear. Upon recall after

six months, the patient’s restoration is strong and beau-

tiful; the patient is still smiling (Figs. 25, 26). lab

Immediate view of the final restorations. Centric rest position view checks the 10 laws of predictability,texture, and height of contour.

View of lateral excursion shows the need to adjust tooth #25 forclearance until completion of the future mandibular restorations.

Protrusive view to check silhouette and smile design.

Canine rise shows functionaliity of final resotrations. A beautiful smile that was always hidden before resorative treat-ment.

Side view of her smile. This view shows the natural appearance of the six anteriorrestoratons.

FORWARDTrends \\\\CATEGORY

38 dentallabproducts SEPTEMBER 2006 www.dentalproducts.net

Layout OK 1st edit 2nd edit 3rd edit Final edit Ad Production

Phot

os c

ourt

esy

of L

uke

Kahn

g,C

DT,

MD

T

Dr. David Bork completed the preparations using the LSK Treat-ment Plan Prep Guuide Model.

Restorations in the second bake stage with multi-layeredporcelain powders.

Restoration surfaces checked for texture and three-dimensionalesthetics.

Procera zirconia substructures were used to mask thediscolored preparatons.

15 16

17 18

19 20

21 22

23 24

25 26

The LSK treatment

The final outcome