C O V E R S T O R Y

Contemporary crown-lengthening therapy

A review
Timothy J. Hempton, DDS; John T. Dominici, DDS, MS

n contemporary dentistry, dentists are

I confronted on a daily basis with clinical

decision making regarding dentition
affected with significant caries or sub-
gingival fractures. The dentist weighs
the clinical findings and patients’ concerns in
the balance to determine if the tooth or teeth
should be extracted or restored. We are, of
ABSTRACT
Background. The authors conducted a literature review
regarding the rationale, basic surgical principles, contraindica-
tions and wound healing associated with periodontal crown-
lengthening surgery. They present a report of a clinical case
illustrating crown lengthening with osseous resection.
course, in an age of dental implants, an era in
Types of Studies Reviewed. The authors evaluated
which heroic efforts to salvage extensively
clinical and radiographic studies, as well as literature
damaged teeth are
reviews. They selected only publications that pertained to the
This article is a preview of a waning. This, how-
presentation that will be surgical exposure of the natural dentition to facilitate restora-
given at the American Dental
ever, does not mean
tive therapy, esthetic concerns or both.
Association’s 151st Annual that dentists should
Results. Periodontal crown lengthening can be used for
Session and World Market- abandon tools com-
place Exhibition. The annual esthetic enhancement in the presence of delayed passive erup-
session information begin-
monly used to pre-
tion. Moreover, for teeth with subgingival caries, fractures or
ning on page 721 provides serve the natural
both, this treatment can establish a biological width and, if
complete details on the dentition, tools such
program. needed, a ferrule length facilitating prosthetic management.
as complex restora-
Crown-lengthening surgery involves various techniques,
tive treatment, pos-
including gingivectomy or gingivoplasty or apically positioned
sible concomitant endodontic therapy and
flaps, which may include osseous resection. Authors of wound-
periodontal therapy. Moreover, if the patient
healing investigations have reported that an average of 3 mil-
wishes to retain part or all of his or her own
limeters of supragingival soft tissue will rebound coronal to
dentition, providing the outcomes of these
the alveolar crest and can take a minimum of three months to
treatment options are predictable, the dentist
complete vertical growth.
should consider honoring those wishes.
Clinical Implications. Initiation of final prosthetic treat-
When caries or fractures are extensive
ment should wait at least three months and possibly up to six
and subgingival, a dentist may opt to use
months for esthetically important areas, as the free gingival
crown-lengthening therapy to expose solid
margin requires a minimum of three months to establish its
tooth structure and thus to facilitate
final vertical position. Dentists must be aware that osseous
restorative therapy. Our purpose in this
resection could affect periodontal stability and may pose a
article is to review the goals, basic surgical
contraindication to crown-lengthening therapy.
principles and wound healing associated
Key Words. Crown lengthening; gingivoplasty.
with crown-lengthening surgery. In addi-
JADA 2010;141(6):647-655.
tion, we discuss potential positive and nega-
tive outcomes of this therapy. In addition,
we present a report of a clinical case fol-
Dr. Hempton is an associate clinical professor, School of Dental Medicine, Tufts University,
lowed for eight years to illustrate the con- Boston. He also maintains a private practice in periodontics and implantology in Dedham,
cepts outlined in this review. Mass. Address reprint requests to Dr. Hempton at 347 Washington St., Suite 103, Dedham,
We used PubMed and Google Scholar Mass. 02026, e-mail “timothyhempton@gmail.com”.
Dr. Dominici is a staff endodontist and faculty member, General Practice Residency and
search engines to identify pertinent litera- Prosthodontic Residency Programs, Michael E. DeBakey Veterans Administration Medical
ture regarding crown lengthening and res- Center, Houston.

JADA, Vol. 141 http://jada.ada.org June 2010 647

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
C O V E R S T O R Y

toration by using the key words “ferrule,” “posts,” exposure if the free gingival margin already
“endodontic dowel core,” “post retention,” “root approximates the CEJs of the dentition in an
fracture,” “endodontics,” “core restoration,” “post esthetic area. Moreover, an altered morphology of
designs,” “fracture resistance” and “post-core.” the anterior dentition’s interdental papillae after
healing also is a concern. Black triangles may
RATIONALE FOR CROWN-LENGTHENING develop if the postresection distance between the
SURGERY
contact area and the interdental osseous crest is
Esthetic and functional concerns. The indica- greater than 5 millimeters.4
tions for crown-lengthening surgery include The biological width. In addition to exposing
esthetic enhancement, exposure of subgingival supragingival tooth structure for restorative
caries, exposure of a fracture or some combination therapy, dentists excise tissues so that crown
of these. Crown-lengthening surgery has been margins do not impinge on the so-called biological
categorized as esthetic or functional. The term width. A review of the literature reveals differing
“functional” relates to exposure of subgingival opinions regarding the occlusoapical length of the
caries, exposure of a fracture or both. Often, the biological width. Gargiulo and colleagues5 de-
discussion of crown lengthening in the anterior scribed the dimensions of the dentogingival junc-
sextants is presented in the context of esthetic tion. They reported the average length of the den-
surgery. Excess gingival display can occur when togingival junction to be 2.04 mm. They identified
passive eruption has been delayed. The result is the subcomponents of the dentogingival junction
the appearance of short clinical crowns. In the as the connective-tissue attachment (mean value:
presence of a medium or a high lip line, this con- 1.07 mm) and the epithelial attachment (mean
dition is more noticeable. If the patient desires an value: 0.97 mm). Vacek and colleagues6 also
anterior dentition that is more normal in tooth investigated the dimensions of the dentogingival
length, resective treatment that exposes the junction in human cadaver specimens. They
anatomical crowns may be warranted.1,2 reported mean values of 0.77 mm for the connec-
Indeed, functional and esthetic therapy can tive-tissue attachment and 1.14 mm for the
converge in the esthetic zone when subgingival epithelial attachment. Ingber and colleagues7 sug-
caries does not extend greatly or at all to the root. gested that the term “biologic width” relates to
In these cases, the dentist may need a surgical the average value of the dentogingival junction—
stent as a guide to determine the position of the that is, approximately 2 mm. They suggested that
new crown margins. If the interdental tissue an additional 1 mm be added coronal to the 2 mm
needs to be removed during surgery, the potential dentogingival junction as an optimal distance
for an esthetic compromise can be reduced or between the bone crest and a restorative margin.
eliminated via compensating prosthetic crown The authors reasoned that “adding the 1 mm to
contours. The dentist can conceal or correct the average 2 mm of the biologic width estab-
widened embrasure areas that may result after lishes a minimum dimension of 3 mm coronal to
healing from the surgical procedure by length- the alveolar crest that is necessary to permit
ening and widening the crown contact areas to healing and proper restoration of the tooth.”7
accommodate the new morphology of the inter- Nevins and Skurow8 also described the impor-
proximal papillae. tance of a 3-mm biological dimension separating
A caveat that the dentist must address for the osseous crest by a safe distance from the
crown lengthening in areas of the dentition visible plaque associated with crown margins.
during smiling is the potential for an esthetic com- In contemporary practice, it generally is
promise relative to the gingival framework. In an accepted that a 3-mm distance would significantly
esthetically important area in which the free gin- reduce the risk of periodontal attachment loss
gival margin may be located significantly coronal induced by subgingival restorative margins.
to the cementoenamel junctions (CEJs) of the den- Placing the restoration in close proximity to the
tition, resection of these excess tissues may not osseous crest has been demonstrated in a human
pose a high risk of developing a problematic situa- clinical study to induce chronic inflammation.9
tion. This is true, even if full-coverage restorations
are not planned, as long as the interdental tissues
are not involved in the process of resection.3 Resec- ABBREVIATION KEY. CEJs: Cementoenamel
tive therapy, however, may result in facial root junctions.

648 JADA, Vol. 141 http://jada.ada.org June 2010

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
 C O V E R S T O R Y

Moreover, results from an animal

investigation involving histologic evalu-
ation indicated that restorative mar-
gins impinging on the osseous crest
may result in bone resorption.10
Ferrule length. A ferrule is a metal
ring or cap intended for strengthening.
The Journal of Prosthetic Dentistry’s
2005 Glossary of Prosthodontic Terms Ferrule No Ferrule
defines a ferrule as a metal band or
A B
ring used to fit the root or crown of a
tooth.11 Sorensen and Engelman12 rede-
fined the ferrule effect as “a 360-degree
metal collar of the crown surrounding
the parallel walls of the dentine
extending coronal to the shoulder of the
preparation.” Figure 1 illustrates a pre-
pared and restored tooth with a ferrule
and a prepared and restored tooth Figure 1. A. A tooth prepared for a full-coverage crown with a ferrule.
without a ferrule. B. A tooth prepared for a full-coverage crown without a ferrule.

For better understanding of the con-

cept of the ferrule, we should examine the tist fills this area with cement to facilitate reten-
dynamics related to full-coverage restorations tion of the post. The physical properties of the
used as a restorative option when tooth structure cement become critical. Fatigue of the cement
has sustained severe damage. Often, the dentist under occlusal stress could result in dislodgement
replaces the lost tooth structure with a founda- of the post and core or, worse, fracture of the tooth.
tion restoration before making the final prepara- The advantage of exposing additional tooth
tion for a full-coverage restoration. Furthermore, structure in this clinical scenario is that the tooth
if the breakdown in tooth structure has impinged preparation can extend in a more apical direction
on the pulp or if little residual supragingival for 1 to 2 mm. This additional surgically exposed
tooth structure remains, endodontic therapy and tooth structure is provided in addition to exposure
concomitant placement of a post and core may be of the biological width so that the crown does not
necessary to allow intracanal retention of the res- invade the attachment apparatus; thereby, a
toration. The placement of the foundation restora- more predictable prosthetic outcome is
tion results in an increase in clinical crown facilitated.13
height, width or both, thereby increasing the This added disclosure of tooth structure can
retention of the full-crown restoration. Under contribute to the formation of a ferrule. In other
these circumstances, however, supragingival words, the restorative margin is circumferentially
crown preparation may result in a margin that is 1 to 2 mm apical to the most apical extent of the
partially or entirely seated on foundation restora- foundation restoration or core buildup. This fer-
tive material. rule height—the length of solid tooth structure
A basic prosthetic concept is that the greatest engaged by the full-coverage restoration—may
amount of retention and resistance to dislodge- permit the forces of occlusion to be dispersed onto
ment of the restoration occurs at the apical one- the periodontal ligament rather than concen-
third of the preparation. It is in this location that trating stresses at the post and core intraradicu-
parallelism is most critical. In this situation, after larly, which can increase the likelihood of failure
placement of a full-coverage restoration, the of the tooth or the restoration. Libman and
forces of occlusion generally may be transmitted Nicholls14 recommended a ferrule of at least
to the foundation restoration. 1.5 mm. Some investigators have reported that a
When a post-and-core restoration is placed to ferrule is not necessary.15,16 They argued that the
retain the core foundation, the occlusal forces may length of the post and the type of cement used
be transmitted to the interface between the negate the concern about obtaining a ferrule.
internal aspect of the root and the post. The den- Morgano and Brackett17 advised that the pros-

JADA, Vol. 141 http://jada.ada.org June 2010 649

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
C O V E R S T O R Y

thetic principle of establishing a ferrule should teeth. The dentist can accomplish a tissue exci-
not be abandoned. sion via a gingivectomy by means of a scalpel, an
As a result of the concern regarding obtaining electrosurge, a radiosurge or a laser. Lasers have
a ferrule, lengthening the crown of a tooth with made their way into conventional dental therapy
minimal supragingival tooth structure may for use in performing gingivectomy or gingivo-
involve additional surgical removal of tissue. In plasty.19 Laser tissue ablation can result in
other words, the dentist may be required to excise adequate exposure of tooth structure with min-
both hard and soft tissue to facilitate development imal or no bleeding. This type of tissue removal
of a biological width of 3 mm, as well as a ferrule can result in a dry field, thus allowing the clini-
length of 1.5 mm. cian to place a restoration immediately.
Attempting to obtain a ferrule with additional The clinician, however, should not ignore the
resection is not without its problems. Gegauff18 concern regarding the width of gingiva in an
pointed out that an attempt to gain an adequate occlusal apical height. Maynard and Wilson20 rec-
ferrule via a crown-lengthening procedure may ommended a minimum of 3 mm of attached gin-
result in compromise of tooth and biomechanical giva in the presence of subgingival restorative
leverage. He noted that the more apical relocation therapy. A gingivectomy, no matter what tool the
of the crown margin after crown-lengthening pro- dentist uses to accomplish the excision, could
cedures resulted in a preparation result in complete removal of
with a thinner cross section. This attached gingival tissue.
Lengthening the
reduction combined with the altered If soft-tissue excision via a gin-
crown to root ratio could result in a crown of a tooth givectomy would result in a postop-
weakened tooth. Orthodontic extru- with minimal erative gingival width of less than
sion may be another option to supragingival tooth 3 mm, one should consider the api-
expose tooth structure in some clin- structure may involve cally positioned flap as an alterna-
ical situations. Any method used to additional surgical tive to a simple gingivectomy.21,22 If
increase the ferrule length will the pretreatment level of gingiva is
removal of tissue.
reduce the root length invested in minimal, the dentist could make a
bone and possibly make the crown to sulcular incision and position the
root ratio unfavorable. Furthermore, surgical and flap apically to the osseous crest.23 This not only
orthodontic procedures add to the cost of restoring would preserve the amount of gingiva but also
the tooth and prolong treatment. would increase the width of the attached gingiva
Most research investigating the ferrule has after healing.
taken the form of in vitro studies of single-rooted Another parameter to consider is the need to
teeth. The influence of the ferrule effect on multi- visualize the bone. If the underlying bone crest is
rooted teeth is an area for further research. Also, less than 3 mm from the level of gingival resec-
without supporting clinical research or prospec- tion, then the dentist should consider using an
tive data, the clinician must question whether elevated flap procedure for access. A simple exci-
appropriate restorative treatment still can be per- sion of tissue probably would result in regrowth of
formed when a ferrule is absent or shorter than soft tissue if the osseous crest is less than 3 mm
that advocated in the in vitro studies. apical to the existing free gingival margin. In
addition, access to the bone yields the opportunity
BASIC SURGICAL CROWN-LENGTHENING to perform additional resection of bone if the den-
PROCEDURES
tist also intends to expose a ferrule.
Soft tissue. To plan a crown-lengthening pro- Osseous management. Regarding esthetic
cedure, a dentist must think in three dimensions. implant dentistry, Garber and colleagues24 stated,
In addition, he or she should be concerned about “The tissue is the issue, but the bone sets the
the quantity and quality of residual gingival tis- tone.” In fact, this concept also is true for out-
sues left behind after the resected tissue has comes of periodontal surgery. The key to success
healed completely. is a three-dimensional analysis of the clinical
As a result, the first concern in flap design or objectives associated with the osseous component
excision is the height of gingiva present on the of the proposed crown-lengthening surgery. The
facial and lingual aspects of the involved tooth or first dimension is the occlusoapical dimension,

650 JADA, Vol. 141 http://jada.ada.org June 2010

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
 C O V E R S T O R Y

the second is the mesiodistal dimension and the width). The flap for this procedure could be a
third is the buccolingual dimension. one-tooth flap with two adjacent vertical
Two terms that describe osseous resection are releasing incisions.
“ostectomy” and “osteoplasty.” “Ostectomy” refers When the tooth will be treated with a Class II
to removal of supporting bone; “osteoplasty” restoration or a full-coverage crown, the inter-
refers to removal of nonsupporting bone. proximal bone may need to be resected. In this
Regarding tools used for bone resection, a dentist event, the dentist resects interproximal bone to
can use hand chisels, high-speed rotary instru- establish a distance associated with health
mentation or a piezoelectric cutting device. No between the restorative margin and the new,
matter what tool the dentist uses, he or she more apical level of bone. As a result, the inter-
should ensure that the treated bone is moistened proximal bone is apical to the facial and lingual
constantly during the procedure to prevent desic- bone. The dentist, having created reverse archi-
cation and associated postoperative pain and tecture, needs to evaluate the second dimension,
delayed healing. the mesiodistal dimension. To reestablish positive
When resective osseous surgery is performed to architecture, the dentist would need to resect
eliminate osseous deformities or reshape healthy facial and lingual bone mesial and distal to the
bone for exposure of tooth structure, the final con- interproximal area.
tours of the underlying osseous The third dimension to osseous
structure influence the overlying gin- resection is the buccolingual dimen-
In an esthetic
gival tissues.25 When the bone has sion. Periodontal biotype is related
positive architecture after therapy, crown-lengthening to thickness of periodontal tissues.
wound healing results in scalloped procedure, bone Thick biotypes may consist of thick
gingival architecture with minimal removal plays an bone, thick soft tissue or both. After
sulcus depth. The achieved reduction important role in the elevating the flap, the dentist may
in probing depths can be maintained final location of the note an osseous ledge or exostosis.
in the long term for nonsmokers and Thick bone often occurs on the
free gingival margin
former smokers who practice proper palatal aspect of the maxillary
oral hygiene and compliance with a after healing. molar dentition.29 It also can be pre-
professional maintenance program.26 sent on the lingual border of the
If reverse architecture remains after a tooth mandible.30 Horning and colleagues31 examined 52
with a surrounding healthy periodontium has modern skeletal specimens and reported buccal
undergone crown lengthening, excess gingival alveolar bone enlargements associated with 25
tissue may rebound in the healing phase. This percent of all teeth examined. Reduction of
rebound would result in inadequate exposure of osseous ledging or an exostosis via osteoplasty
the treated dentition. If periodontal disease and was recommended originally by Schluger32 in
associated intrabony defects are present in con- 1949 and subsequently by Friedman33 in 1955. It
junction with the need to lengthen a tooth’s is our opinion that reduction of alveolar bone
crown, the dentist should eliminate those defor- enlargements reduces the risk of postoperative
mities and establish positive architecture. Failure rebound of soft tissue.
to eliminate osseous deformities poses a risk of In an esthetic crown-lengthening procedure,
pockets’ being present after surgery.27,28 bone removal plays an important role in the final
The extent of bone resection. In deciding location of the free gingival margin after healing.
which and how much bone should be removed, the Coslet and colleagues34 described the clinical cir-
dentist’s first concern is determining whether the cumstance known as “delayed passive eruption.”
lesion associated with the tooth requires Class V, In this condition, excess gingiva covers the
Class II or full-coverage restorative treatment. If anatomical crown, thereby resulting in a short
the lesion is located solely on the facial aspect, clinical crown. The classification system described
then the dentist can perform the needed osseous by the authors indicated that in some cases, when
removal solely on the facial or lingual aspect. gingiva is significantly coronal to the CEJ, the
Moreover, the resection would be limited to osseous crest may be located at or within close
altering the bone in the occlusoapical dimension, proximity to the CEJ. For a predictable outcome
thereby attaining a 3-mm dimension of supra- in these cases, flap elevation with access to the
crestal tooth exposure (distance for a biological facial osseous crest enables the dentist to visu-

JADA, Vol. 141 http://jada.ada.org June 2010 651

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
C O V E R S T O R Y

an apical level.38 Researchers

have observed that if the
margin of the flap is posi-
tioned at the level of the
osseous crest, a postoperative
vertical gain or rebound in
supracrestal soft tissues
occurs that averages 3 mm.39,40
If the flap margin is placed at
a level more coronal to the
Figure 2. Tooth no. 4 prepared for a full- Figure 3. Pretreatment radiograph of tooth
coverage crown. Supragingival tooth struc- no. 4. Teeth nos. 3 and 4 had undergone newly established osseous
ture is not visible, and there is no ferrule. endodontic therapy. crest, less vertical gain or
rebound in supracrestal soft
tissues has been observed.41
After a crown-lengthening
procedure, a common question
pertaining to restorative or
prosthetic treatment regards
when the final tooth prepara-
tion can begin and when
impressions, if needed, can be
taken. A key determinant for
initiating prosthetic therapy
Figure 4. After flap elevation and before Figure 5. Buccal view after osseous resection.
resection, the buccal osseous morphology Tooth structure is exposed to establish a biological is the final position of the free
is exposed. width and ferrule length. gingival margin. This is par-
ticularly true in cases in
alize and resect an appropriate amount of bone. which the treated dentition is of esthetic concern
Altered passive eruption also can be observed to the patient.
in the posterior sextants. The clinical crowns of Lanning and colleagues42 demonstrated that
the posterior dentition can be significantly coronal advancement of the healing tissues from
shorter than the anatomical crowns. In cases in the osseous crest averages 3 mm by three months’
which fixed prosthetic therapy is needed, reposi- time after surgery. They also determined that six
tioning the free gingival margin to the level of the months after surgery, no further significant
CEJ may be all that is necessary to expose caries changes in the vertical position of the free gin-
and establish cleansable gingival embrasure gival margin were apparent. Brägger and col-
areas.35 The effect on periodontal support is negli- leagues43 also noted that during a six-month
gible in these cases, as the resection of soft tissue healing period after crown lengthening, perio-
and bone essentially is the resection of excess dontal tissues were stable, with minimal changes
periodontal tissues. in the level of the gingival margin. From these
Contraindications to osseous resection. findings, one can conclude that regarding final
Ostectomy becomes a liability when the stability prosthetic treatment in the esthetic zone, the
of the treated dentition may be affected. Gener- waiting period after a crown-lengthening pro-
ally, dentists should refrain from excessive cedure should be six months.
osseous removal if it will compromise the crown
to root ratio. In addition, removal of bone in the DISCUSSION
furcation region associated with the root trunk is Crown-lengthening surgery is a resective procedure
a concern.36 The dentist also should avoid used to induce recession surgically. To do so, the
removing bone in the furcation area.37 clinician either excises or apically positions soft tis-
Wound healing. After the surgical procedure sues. In addition, the underlying osseous structure
concludes, the healing phase begins. Research has plays a critical role in the final wound healing.
shown that when the clinician creates an apically When osseous deformities already are present,
positioned flap with an osseous resection pro- osseous resection and apically positioned flaps
cedure, the biological width reestablishes itself at would have the dual advantage of reducing probing

652 JADA, Vol. 141 http://jada.ada.org June 2010

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
 C O V E R S T O R Y

depths and exposing tooth

structure for restorative
therapy. Modification of the
morphology of the under-
lying bone must be evalu-
ated in three dimensions.
With respect to proximal
lesions or full-coverage
restorations, crown-
lengthening surgery
involves changes in the Figure 6. Bone architecture after elevation of a Figure 7. Palatal view of osseous
palatal flap and before osseous resection. morphology after osseous resection. Positive
mesiodistal dimension to architecture is established at an apical level.
establish positive architec-
ture. As a result of the need
to dissipate the changes in
the hard and soft tissues of
the adjacent teeth, length-
ening the crown of one
tooth with a proximal lesion
essentially becomes a three-
tooth surgery.
With respect to pros-
Figure 8. View of apically positioned buccal flap Figure 9. Buccal view eight weeks after
thetic therapy, crown sutured with periosteal sutures. crown-lengthening surgery. Periodontal tis-
lengthening results in sues still are healing. Plaque-control measures
more cleansable gingival need to be reviewed with the patient.

embrasure areas adjacent

to full-coverage crowns.
Moreover, this procedure
can enable the clinician to
establish a biological width
and a ferrule length.
Obtaining adequate expo-
sure to establish both of
these parameters should
be weighed against the
possibility of compromising Figure 10. Buccal view of the maxillary right pos-
terior sextant eight years after periodontal and
Figure 11. Radiograph of teeth nos. 3, 4 and
5 eight years after treatment with a crown-
the osseous support of the prosthetic treatment. Teeth nos. 3 and 4 have been lengthening procedure and placement of
tooth undergoing crown restored with porcelain-fused-to-metal restorations. full-coverage crowns.

lengthening, the osseous

support associated with the adjacent teeth or both. indicated that endodontic therapy had been per-
Regarding initiation of final prosthetic treat- formed in conjunction with placement of a post-
ment, researchers have observed an average ver- and-core foundation restoration. A periapical
tical growth of 3 mm of supraosseous gingiva.39,40 radiograph indicated that the root length asso-
The final position of the free gingival margin can ciated with tooth no. 4 appeared to be adequate to
occur at three months after surgery but may allow for osseous resective therapy (Figure 3).
occur as long as six months after surgery. For As adequate root length was available, and a
treated areas in the esthetic zone, a waiting ferrule was not present, the clinician decided to
period of six months is advisable. perform a crown-lengthening procedure. Figures
4 and 5 show the flap extending from the distal
CASE REPORT aspect of tooth no. 3 to the mesial line angle of
A 58-year-old woman in good health had a sub- tooth no. 6. These images display the osseous
gingival foundation restoration associated with levels before osseous resection. The clinician noted
tooth no. 4 (Figure 2). A preoperative radiograph that the length of supraosseous tooth structure

JADA, Vol. 141 http://jada.ada.org June 2010 653

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
C O V E R S T O R Y

was inadequate for establishment of a biological dontics Restorative Dent 1994;14(2):154-165.

7. Ingber JS, Rose LF, Coslet JG. The “biologic width”: a concept in
width or ferrule. periodontics and restorative dentistry. Alpha Omegan 1977;70(3):62-65.
The clinician performed osseous resection, 8. Nevins M, Skurow HM. The intracrevicular restorative margin, the
biologic width, and the maintenance of the gingival margin. Int J Perio-
establishing 4.5 mm of supraosseous tooth struc- dontics Restorative Dent 1984;4(3):30-49.
ture on the buccal and palatal aspects of tooth 9. Günay H, Seeger A, Tschernitschek H, Geurtsen W. Placement of
the preparation line and periodontal health: a prospective 2-year clin-
no. 4. In addition, the clinician attained positive ical study. Int J Periodontics Restorative Dent 2000;20(2):171-181.
osseous architecture that extended from the 10. Parma-Benfenali S, Fugazzoto PA, Ruben MP. The effect of restora-
tive margins on the postsurgical development and nature of the peri-
distal aspect of tooth no. 3 to the mesial aspect of odontium: part I. Int J Periodontics Restorative Dent 1985;5(6):30-51.
tooth no. 5. Figures 6 and 7 show the area after 11. The glossary of prosthodontic terms. J Prosthet Dent 2005;94(1):38.
12. Sorensen JA, Engelman MJ. Ferrule design and fracture resis-
the osseous resection. After completing osseous tance of endodontically treated teeth. J Prosthet Dent 1990;63(5):
therapy, the clinician positioned the flaps apically 529-536.
13. Wagenberg BD, Eskow RN, Langer B. Exposing adequate tooth
by means of periosteal sutures (Figure 8). This structure for restorative dentistry. Int J Periodontics Restorative Dent
type of sutured closure attaches the flap at an 1989;9(5):322-331.
14. Libman WJ, Nicholls JI. Load fatigue of teeth restored with cast
apical level to connective tissue still present on posts and cores and complete crowns. Int J Prosthodont 1995;8(2):
the facial aspect of the buccal bone (as described 155-161.
15.Al-Hazaimah H, Gutteridge DL. An in vitro study into the effect of
by Kramer and colleagues44). the ferrule preparation on the fracture reisistance of crowned teeth
Figure 9 shows additional exposure of tooth incorporating prefabricated post and composite core restoration. Int
Endodontic J 2001;34(1):40-46.
structure at eight weeks after the procedure. At 16. Meng Q-F, Chen Y-M, Guang H-B, Yip KH-K, Smales RJ. Effect
three months after surgery, the patient returned of a ferrule and increased clinical crown length on the in vitro fracture
resistance of premolars restored using two dowel-and-core Systems.
to the restorative dentist for fabrication of full-cast Oper Dent 2007;32(6):595-601.
restorations associated with teeth nos. 4 and 3. 17. Morgano SM, Brackett SE. Foundation restorations in fixed
prosthodontics: current knowledge and future needs. J Prosthet Dent
Figure 10 is a photograph and Figure 11 a radio- 1999;82(6):643-657.
graph of the restored area eight years after 18. Gegauff AG. Effect of crown lengthening and ferule placement on
static load failure of cemented cast post-cores and crowns. J Prosthet
treatment. Dent 2000;84(2):169-179.
19. Research, Science and Therapy Committee of the American
CONCLUSION Academy of Periodontology. Lasers in periodontics. J Periodontol 2002;
73(10):1231-1239.
Crown-lengthening surgery can be a viable option 20. Maynard JG, Wilson RD. Physiologic dimensions of the periodon-
tium significant to the restorative dentist. J Periodontol 1979;50(4):
for facilitating restorative therapy or improving 170-174.
esthetic appearance. When planning a crown- 21. Nabers CL. Repositioning the attached gingiva. J Periodontol
1954;25:38-39.
lengthening procedure, the dentist should eval- 22. Ariaudo A, Tyrrell HA. Repositioning and increasing the zone of
uate the patient’s complete periodontal condition attached gingiva. J Periodontol 1957;28:106-110.
23. Pippin DJ. Fate of pocket epithelium in an apically positioned
and disclose all possible treatment options to the flap. J Clin Periodontol 1990;17(6):385-391.
patient. In cases involving the possibility of a neg- 24. Garber DA, Salama H, Salama MA. Multidisciplinary cases:
lessons learned. Paper presented at: 24th Annual Meeting of the
ative esthetic outcome, compromise to the support American Academy of Esthetic Dentistry; Whistler, British Columbia,
of the dentition involved in the surgical procedure Canada; Aug. 6, 1999.
25. Matherson DG. An evaluation of healing following periodontal
or both, extraction and implant therapy or con- osseous surgery in monkeys. Int J Periodontics Restorative Dent 1988;
ventional prosthetic therapy may be a more com- 8(5):9-39.
26. Kaldahl WB, Kalkwarf KL, Patil KD, Molvar MP, Dyer JK. Long-
pelling solution. ■ term evaluation of periodontal therapy, II: incidence of sites breaking
down. J Periodontol 1996;67(2):103-108.
Disclosure. Drs. Hempton and Dominici did not report any 27. Olsen CT, Ammons WF, van Belle G. A longitudinal study com-
disclosures. paring apically repositioned flaps, with and without osseous surgery.
Int J Periodontics Restorative Dent 1985;5(4):1-33.
The authors thank Dr. Jeffrey Harrison, Wellesley, Mass., for the 28. Kaldahl W, Kalkwarf K, Patil K, Dyer J, Bates R. Long-term
prosthetic therapy provided in the clinical case presented in this evaluation of periodontal therapy, I: response to 4 therapeutic modali-
article. ties. J Periodontol 1996;67(2):93-102.
29. Nery EB, Corn H, Eisenstein IL. Palatal exostosis in the molar
1. Allen EP. Surgical crown lengthening for function and esthetics. region. J Periodontol 1977;48(10):663-666.
Dent Clin North Am 1993;37(2):163-179. 30. Sonnier KE, Horning GM, Cohen ME. Palatal tubercles, palatal
2. McGuire MK. Periodontal plastic surgery. Dent Clin North Am tori, and mandibular tori: prevalence and anatomical features in a U.S.
1998;42(3):411-465. population. J Periodontol 1999;70(3):329-336.
3. Hempton TJ, Esrason F. Crown lengthening to facilitate restora- 31. Horning GM, Cohen ME, Neils TA. Buccal alveolar exostoses:
tive treatment in the presence of incomplete passive eruption. J Calif prevalence, characteristics, and evidence for buttressing bone forma-
Dent Assoc 2000;28(4):290-291, 294-296, 298. tion. J Periodontol 2000;71(6):1032-1042.
4. Tarnow DP, Magner AW, Fletcher P. The effect of the distance 32. Schluger S. Osseous resection: a basic principle in periodontal
from the contact point to the crest of bone on the presence or absence of surgery. Oral Surg Oral Med Oral Pathol 1949;2(3):316-325.
the interproximal dental papilla. J Periodontol 1992;63(12):995-996. 33. Friedman N. Periodontal osseous surgery: osteoplasty and ostec-
5. Gargiulo A, Wentz F, Orban B. Dimensions and relations of the tomy. J Periodontol 1955;26:257-259.
dentogingival junction in humans. J Periodontol 1961;32:261-267. 34. Coslet JG, Vanarsdall R, Weisgold A. Diagnosis and classification
6. Vacek JS, Gher ME, Assad DA, Richardson AC, Giambarresi LI. of delayed passive eruption of the dentogingival junction in the adult.
The dimensions of the human dentogingival junction. Int J Perio- Alpha Omegan 1977;70(3):24-28.

654 JADA, Vol. 141 http://jada.ada.org June 2010

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.
 C O V E R S T O R Y

35. Malament KA. Considerations in posterior glass-ceramic restora- supraosseous gingivae before and after crown lengthening. J Perio-
tions. Int J Periodontics Restorative Dent 1988;8(4):32-49. dontol 2007;78(6):1023-1030.
36. Dilbart S, Capri D , Kachouh I, Van Dyke T, Nunn ME. Crown 41. Deas DE, Moritz AJ, McDonnell HT, Powell CA, Mealey BL.
lengthening in mandibular molars: a five-year retrospective radio- Osseous surgery for crown lengthening: a 6-month clinical study. J
graphic analysis. J Periodontol 2003;74(6):815-821. Periodontol 2004;75(9):1288-1294.
37. Ochsenbein C. A primer for osseous surgery. Int J Periodontics 42. Lanning SK, Waldrop TC, Gunsolley JC, Maynard JG. Surgical
Restorative Dent 1986;6(1):8-47. crown lengthening: evaluation of the biological width. J Periodontol
38. Oakley E, Rhyu IC, Karatzas S, Gandini-Santiago L, Nevins M, 2003;74(4):468-474.
Caton J. Formation of the biologic width following crown lengthening 43. Brägger U, Lauchenauer D, Lang NP. Surgical lengthening of the
in nonhuman primates. Int J Periodontics Restorative Dent 1999;19(6): clinical crown. J Clin Periodontol 1992;19(1):58-63.
529-541. 44. Kramer GM, Nevins M, Kohn JD. The utilization of periosteal
39. Pontoriero R, Carnevale G. Surgical crown lengthening: a 12- suturing in periodontal surgical procedures. J Periodontol 1970;41(8):
month clinical wound healing study. J Periodontol 2001;72(7):841-848. 457-462.
40. Perez JR, Smuckler H, Nunn ME. Clinical evaluation of the

JADA, Vol. 141 http://jada.ada.org June 2010 655

Copyright © 2010 American Dental Association. All rights reserved. Reprinted by permission.