Surgical Lengthening of the Clinical Tooth Crown by Using Semiconductor Diode Laser: A Case Series

Abstract

Surgical crown lengthening procedures are performed to aid in the retention of prostheses by allowing proper tooth preparation, impression procedures and placement of restorative margins. A healthy periodon-tium is a key to a successful prosthesis. It is necessary to prepare periodontal tissues properly before restorative treatment to ensure good form, function, and esthetics of the masticatory apparatus, as well as patient comfort. There are different surgical techniques used for crown lengthening, eg, gingivectomy, apically displaced flap, crown lengthening with ostectomy, and lasers. The success of such procedures depends on the biological width. The present case series describes surgical crown lengthening procedures by using semiconductor diode laser, as the diode laser technique is easier, is well accepted by patients, and provideds predictable postoperative results.

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Vol 10, No 1, 2010 53
CASE REPORT
Surgical Lengthening of the Clinical
Tooth Crown by Using Semiconductor
Diode Laser: A Case Series
Sanjay B. Lagdivea, Sushma S. Lagdiveb, P. P. Marawarc, Aruna J. Bhandarid,
Abhishek Darekare, Veena Saraff
a Professor, Dept. of Prosthodontics, Rural Dental College, Loni. Dist., Ahmednagar, Maharashtra,
India.
b Senior Lecturer, Dept. of Periodontics, Rural Dental College, Loni. Dist., Ahmednagar,
Maharashtra, India.
c Professor and Head, Dept. of Periodontics, Rural Dental College, Loni. Dist., Ahmednagar,
Maharashtra, India.
d Professor Dept. of Prosthodontics, Rural Dental College, Loni. Dist.. Ahmednagar, Maharashtra, India.
e Postgraduate Student, Dept. of Prosthodontics, Rural Dental College, Loni. Dist., Ahmednagar,
Maharashtra, India.
f Senior Lecturer, Department of Prosthodontics, Rural Dental College, Loni. Dist., Ahmednagar,
Maharashtra, India.
Abstract: Surgical crown lengthening procedures are performed to aid in the retention of prostheses by allow-
ing proper tooth preparation, impression procedures and placement of restorative margins. A healthy periodon-
tium is a key to a successful prosthesis. It is necessary to prepare periodontal tissues properly before restorative
treatment to ensure good form, function, and esthetics of the masticatory apparatus, as well as patient comfort.
There are different surgical techniques used for crown lengthening, eg, gingivectomy, apically displaced ap, crown
lengthening with ostectomy, and lasers. The success of such procedures depends on the biological width.
The present case series describes surgical crown lengthening procedures by using semiconductor diode laser, as
the diode laser technique is easier, is well accepted by patients, and provideds predictable postoperative results.
Keywords: diode laser, crown lengthening, biological width, gingivectomy, gingivoplasty.
J Oral Laser Applications 2010; 10: 53-57. Submitted for publication: 31.12.09; accepted for publication: 11.03.10.
Robicsek1 pioneered the gingivectomy procedure.
Where gingivectomy involves the excision of the
soft tissue wall of a pathological periodontal pocket,
gingivoplasty is a reshaping of the gingiva to create
physiological gingival contours. Gingivectomy and gin-
givoplasty can be done conventionally using a scalpel,
rotary coarse diamond burs, a periodontal knife, elec-
trodes, chemosurgery, or laser.
Laser stands for Light Amplication by Stimulated
Emission of Radiation, and is the new technique for
soft tissue surgery.2 Lasers have been used in den-
tistry since the beginning of the 1980s. Semiconductor
diode laser has been used for gingivectomy, frenec-
tomy, incisional and excisional biopsy, soft tissue tu-
berosity reduction, operculum removal, coagulation of
graft donor site, and exposure of soft tissue covering
osseointegrated implants.
The present case series describes three case re-
ports of gingivectomy and gingivoplasty using semicon-
ductor diode lasers, which is a simple, effective method
that produces good results with patient satisfaction.
CASE DESCRIPTIONS
Three patients were treated who had gummy and
esthetically unpleasant smiles, due to uneven gingival

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54 The Journal of Oral Laser Applications
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margins in the maxillary anterior region. They had no
systemic diseases associated with healing disturbances,
pathological gingival enlargement (eg, drug associated,
inammatory or idiopathic etc). The surgical procedure
and follow-up was explained in detail to the patients
and consent forms were signed.
Case 1
A 24-year-old male patient visited the Department
of Prosthodontics, Rural Dental College, Loni for the
replacement of existing crown restorations. Clinical
examination revealed ceramic crowns on teeth 11 and
12 in place for 2 years, short clinical height of teeth
11 and 12, and uneven gingival margins on these teeth
comparison with teeth 21 and 22 (Fig 1a). Sulcus depth
measured using a pocket marker was more than 2 mm,
and patient was apprehensive of the scalpel, so gingi-
vectomy using semiconductor diode laser was planned.
To improve the oral hygiene, oral prophylaxis was
done and oral hygiene instructions were given. Gin-
givectomy was planned from mesial of the maxillary
central incisor to distal of the maxillary lateral incisor
at the level of the maxillary left central and lateral inci-
sors by measuring crown height.
A semiconductor diode surgical laser unit (ezlase,
wavelength 800 to 940 nm, Biolase Technologies; Irvine,
CA, USA) bearing a 400-micron-diameter disposable tip
with contact method and power set at 4 W in continu-
ous pulse mode was used for gingivectomy and gingivo-
plasty of the maxillary right central and lateral incisors.
The semiconductor diode laser was used in continuous
mode, and was operated in a contact method using a
exible ber optic delivery system. As there is no need
for anesthesia, only topical lignocaine spray was used.
Laser ablation started from the base of bleeding points
created by the pocket marker. Ablation was performed
using light brushing strokes and the tip was kept in con-
tinuous motion.3 Remnants of the ablated tissue were
removed using sterile gauze dampened with saline (Fig
1b). Gingivoplasty was done in the interdental papilla
and marginal gingiva to create a normal physiological
contour by changing the tip angulations. This procedure
was repeated until the desired level of marginal tissue
removal was achieved. A smaller laser tip, 300 micron
in diameter, was used at the gingival margin interdental
papilla in order to achieve better control.4
Fig 1a Case 1. Preoperative view. Fig 1b Case 1. Gingival contouring by diode laser.
Fig 1e Case 1. Denitive restoration.
Fig 1c Case 1. 2-week postoperative view. Fig 1d Case 1. Tooth preparation.

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Laser Safety
Safety glasses were worn by the operator, patient and
assistant. Highly reective instruments or instruments
with mirrored surface were avoided as there could be
reection of the laser beam.5
Case 2
A 28-year-old female patient reported to Department
of Prosthodontics with the chief complaint of missing
maxillary anterior teeth and gummy smile. On examina-
tion, crown height was inadequate for abutment teeth
and excessive gingival growth was seen in the edentu-
lous area (Fig 2a). Gingivectomy and gingivoplasty using
laser was planned. After phase I thearpy, gingivectomy
and gingivoplasty was done by using the semiconductor
diode laser in continuous mode, contact method (Fig
2b). Gingival troughing was done in the region of missing
teeth to achieve emergence prole.
Case 3
A 26-year-old male patient was referred to the De-
partment of Prosthodontics for replacement of old
restorations. On examination, teeth 11 and 12 had
been restored with porcelain-fused-to-metal crowns.
Also, the gingival margins were esthetically unpleas-
ant (Fig 3a). The decision was made to lengthen the
crowns using laser, followed by all-ceramic restorations
(Fig 3b).
After surgery, postoperative instructions were given
and patients were recalled after 1, 2, and 3 weeks for
follow-up; and definitive restorations were subse-
quently performed (Figs 1c, 1d, 1e; Figs 2c, 2d, 2e; Figs
3c, 3d).
Clinical Evaluation
Clinical parameters such as bleeding, wound healing,
gingival color, pain, and difculty of procedure were
evaluated immediately and at 1, 2, and 3 weeks post-
operatively. A list of clinical observations and patient
responses prepared by Ishii et al6 and Kawashima et
al7 was used for evaluation.
Fig 2a Case 2. Preoperative view. Fig 2b Case 2. Gingivectomy and gingivoplasty by diode laser.
Fig 2c Case 2. 2-week postoperative view. Fig 2d Case 2. Tooth preparation.
Fig 2e Case 2. Denitive restoration.

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There was no bleeding either immediately postop-
eratively or in the follow-up period. Wound healing
was slightly delayed and the procedure was very easy
to perform. Patients reported no pain during surgery
or follow-up.
DISCUSSION
There are various situations in which surgical crown
lengthening is required, such as restoration of sub-
gingival caries or fracture, inadequate clinical crown
length, and unequal or unesthetic gingival heights. If a
sulcus depth greater than 2 mm is found, especially on
the facial aspect of the tooth, gingivectomy can be per-
formed to lengthen the clinical crown.8
In all the three patients, there was no postopera-
tive pain, swelling or bleeding from the operated area.
Excellent postoperative results were obtained after 2
weeks, as there is delayed healing in laser. Six weeks
postoperatively, denitive restorations were placed and
the results were esthetically pleasant.
Surgical treatment is faster and more favorable for
indirect restorations when higher clinical tooth crown
is necessary.9 Scalpel surgery causes unpleasant bleed-
ing during and after the operation, and it is necessary
to cover the exposed lamina propria with periodontal
pack for 7 to 10 days. The diode laser causes minimal
damage to the periosteum and bone under the gingiva
being treated, and it has the unique property of being
able to remove a thin layer of epithelium cleanly. Al-
though healing of laser wounds is slower than healing
of scalpel wounds, laser wounds are sterile and less
likely to become inamed.10 Blood vessels in the sur-
rounding tissue up to a diameter of 0.5 mm are sealed
by the laser; the primary advantage is hemostasis and a
relatively dry eld.
The semiconductor diode laser is emitted in con-
tinuous-wave or gated-pulsed modes, and is usually
operated in contact mode using a exible ber optic
delivery system. Laser light at 800 to 980 nm is poorly
absorbed in water, but highly absorbed in hemoglobin
and other pigments.11 Since the diode laser basically
does not interact with dental hard tissues, this laser
is an excellent soft tissue surgical laser, indicated for
cutting and coagulating gingiva and oral mucosa, and
for soft tissue curettage or sulcular debridement. The
diode laser exhibits thermal effects because of its
“hot tip” caused by heat accumulation at the end of
the ber, and produces a relatively thick coagulation
layer on the treated surface. The usage is quite similar
to electrocauterization. Tissue penetration of a diode
laser is less than that of the Nd:YAG laser, while the
Fig 3a Case 3. Preoperative view.
Fig 3c Case 3. 2 weeks postoperative view. Fig 3d Case 3. Denitive restoration.
Fig 3b Case 3. Crown lengthening by diode laser.

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rate of heat generation is higher. The advantages of
diode lasers are the smaller size of the units as well
as the lower nancial costs. Diode laser does not pro-
duce any deleterious effect on the root surface. Thus,
it is generally considered that diode laser surgery can
be performed safely in close proximity to dental hard
tissue.
In an in vitro and in vivo study, Moritz et al5 showed
a bactericidal effect of diode laser. They found that an
extraordinarily high reduction of bacteria could be
achieved. It creates locally sterile conditions, which
results in a reduction of bacteremia concomitant to
operation. It is also postulated that low output power
laser mediates an analgesic effect related to depressed
nerve transmission in dentinal hypersensitivity.
Bragger et al12 showed how periodontal tissues
change after surgical clinical tooth crown lengthening.
Six weeks postoperatively, attachment level and prob-
ing depth did not change, and the level of marginal
gingiva established during operation almost precisely
corresponds to the level of marginal gingiva after heal-
ing. According to their study, nal restoration should
be performed not earlier than 6 weeks after the op-
eration, and because of possible retraction, it is recom-
mended to wait longer in esthetical areas.
The usual mechanisms of diode laser that lead to
ablation or decomposition of biological materials are
photochemical, thermal or plasma mediated. Thermal
ablation means that the energy delivered by the laser
interacts with the irradiated material by an absorp-
tion process yielding a temperature rise there. As the
temperature increases at the surgical site, the soft tis-
sues are subjected to warming (37°C to 60°C), protein
denaturization, coagulation (> 60°C), welding (70°C
to 900°C), vaporization (100°C to 150°C), vaporiza-
tion and carbonization (> 200°C).2 The rapid rise in
intracellular temperature and pressure leads to cellular
rupture, as well as release of vapor and cellular debris,
termed the laser plume.
The chief advantages of laser use are: (1) a rela-
tively bloodless surgical and postsurgical course; (2)
the ability to coagulate, vaporize, or cut tissues; (3)
sterilization of the wound site; (4) minimal swelling and
scarring; (5) little mechanical trauma; (6) reduction of
surgical time; (7) high patient acceptance; (8) reduced
postoperative pain, possibly due to the protein co-
agulum that is formed on the wound surface, thereby
acting as a biologic dressing and sealing the ends of the
sensory nerves.
CONCLUSION
There are a number of alternative modalities that will
correct the esthetic problems. The decisive factor is
what works best for the individual patient. From this
case series, it can be concluded that the application of
the diode laser appears to be a safe and effective alter-
native procedure for the treatment of altered gingival
contour.
“It is said the greatest discovery in dentistry in the
past 100 years is the local anesthesia which takes away
the pain. The second greatest discovery in dentistry is
the laser which takes away the needle and the drill.” –
Dr. Philip Ting, DDS, MDS.13
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Contact address: Professor Sanjay B. Lagdive, Department
of Prosthodontics, Rural Dental College, Loni. Dist., Ahmed-
nagar, Maharashtra, India. Tel: +91-982-203-6624. e-mail: lag-
dive_san@ yahoo.co.in