Laser-Assisted Aesthetic Osseous Crown Lengthening During The Crown Preparation Appointment

Once you have been in private practice long
enough, you can pretty much expect the
unexpected. We become very good at not
allowing planning and scheduling mistakes to
disrupt our office or inconvenience the patient.
In cases of complicated cosmetic rehabilitation, the schedule
often depends on patient factors, such as insurance, finances,
work schedule, distance from the office and travel time. For
the treatment of gummy smiles and uneven gingival contours
in the anterior dentition, ideal smile design requires that
rehabilitation be accomplished in several steps, with a lengthy
healing period in between these steps. Proper diagnosis and
correct selection of soft tissue crown lengthening vs. osseous
crown lengthening is the key to the long-term success of our
restorations and maintaining good periodontal health.
This article will showcase the five-year success of osseous
crown lengthening surgery performed with the Waterlase MD
Er,Cr:YSGG 2780nm laser, at the time of crown preparation
and try to explain reasons why such success was possible using
hard tissue laser technology.
Case Report
A healthy 55-year-old female patient with severe generalized
attrition, as indicated by the panoramic X-ray (Fig. 1) has
been undergoing a full mouth rehabilitation, over the previous
five-years. Her initial chief complaint was frequently breaking
her anterior composite restorations. Vertical dimension of
occlusion has been re-established first using composite build
ups and verified for a period of 6 months of normal masticatory
and speech functions. Coincidentally, frequency of
migraine-type headaches has also been reduced as reported
by the patient. During the subsequent 4 years, the posterior
build-ups have been converted to full coverage Lava Zirconia
crowns, leaving only the anterior teeth to be completed. In
2010, the patient retired and moved to Deep River, a town 2
hours drive from Ottawa, and had not been to our office for
a year. In November 2011 she has made an appointment to
start the crowns on the last remaining 6 anterior teeth, 13-23.
The pre-operative photo (Fig. 2) clearly indicated a disharmony
in gingival contours and a slight gummy smile. Upon
quick periodontal examination and bone sounding, a Type 2
aesthetic crown lengthening surgery1was indicated. Without
performing the surgery first, we would either have to fabricate
Laser-Assisted Aesthetic
Osseous Crown Lengthening
During The Crown
Preparation Appointment:
A 5-Year Follow-Up Case Report
Marina Polonsky, DDS, MSc. Laser Dentistry
crowns of various heights, which goes against the whole idea
of elective cosmetic dentistry, or another option would be to
create the crowns with ideal proportions, but thus impinge on
biological width (BW) of teeth 11, 22 and 23.
The impingement on BW would result in gingival tissue
re-establishing its original dimension through bone resorption
or chronic inflammation.1 The anatomy of dentogingival junction
and the concept of biological width has been known since
the 1960’s.2 It is made up of sulcus depth 0.69mm,
epithelial attachment 0.97mm and connective tissue 1.07mm
for a total BW of 2.73mm, or around 3mm from the crestal
bone to the gingival margin (Fig. 3).3 A number of studies
looked at the healing process following osseous periodontal
surgery and showed an average loss of alveolar crest of
0.5-0.8mm at 6 months following the procedure.4 Some
studies found no significant change in free gingival margin
from three to six months,5 while others showed a 12-month
healing period was required.6 Raising a mucoperiosteal flap,
as a general rule, increased both healing time and resorption
of alveolar process.

With the patient in the chair expecting definitive work
to be started on the final phase of her cosmetic transformation,
we were faced with the dilemma: do we perform crown
lengthening surgery today and reschedule crown preparation
by the recommended 3-6 months healing period, or do we
leave unaesthetic gingival contours and make the crowns uneven?
Neither one of these options was palatable to myself or
the patient. Luckily we had at our disposal the Waterlase MD,
hard tissue laser, that has been shown to be effective in the
flapless osseous crown lengthening approach, which allows
predictable and fast healing.7 Effective hemostasis, minimal
healing delay and complete healing of bone defects, within
56 days, has been shown in animal studies.8 Er,Cr:YSGG
2780nm laser wavelength allows for precise surgical removal
Panoramic X-ray prior to VDO correction Pre-op photo at crown preparation
Physiologic dimensions of periodontium significant to restorative dentist.
From Maynard JG et al [3]

74 oralhealth APRIL 2017
of alveolar process of bone and surrounding gingival tissue
with minimal thermal damage.9 The ability to clearly see how
this laser gently removes soft tissue microns at a time without
blood constantly seeping into the surgeon’s field of view is
what makes such surgery possible and even fun for the general
dentist. Using the laser tip as a chisel, we are able to sculpt
the gingival and bony architecture to create a great foundation
for our cosmetic restorations. The lack of thermal side effects
on the hard tissues is what makes this surgery so painless for
the patient and enables us to forego the three months healing
period, and proceed with the fabrication of the final crown
restorations much sooner.10 It is for this reason, we were able
to offer our patient an option of performing Type 2 osseous
crown lengthening prior to crown preparation, in the same appointment,
and still be able to make the final impression and
place definitive restorations, two to three weeks later.
After administering sufficient local anesthesia, to last the
entire 3-hour appointment, the Waterlase MD, with Gold HP
and MZ5 14mm long tip, was used to establish ideal gingival
contours (Fig. 4). Gingiva on the buccal aspect of teeth 11,
22 and 23 was modified using the soft tissue cutting settings
(2.5W, 30Hz, H-mode, 20%W/20%A). A permanent black
marker was used to indicate 3 mm depth on the disposable
fiber tip, which allowed precise removal of crestal bone to
create the desired biological width. Alveolar bone reduction
was performed, using the bone cutting settings (3.0W, 30Hz,
H-mode, 60%W/40%A), until the black mark coincided with
the newly established gingival contour (Fig. 5). The surgical
procedure took approximately 30-40 minutes from the start of
the appointment.
The next step was crown preparation, which was completed
using a conventional high speed handpiece (Fig. 6). By the
time crown preparation was completed, 1.5 hours later, the
bleeding from osseous bone reduction had stopped and the
impression could be taken. Instead of packing a retraction cord,
laser troughing for impression was accomplished with the aid
of Waterlase MD, using same MZ5 14mm long tip, but at the
troughing setting (1.25W, 50Hz, S-mode, 10%W/10%A). The
buccal gingiva of teeth 11, 22 and 23 did not require any further
retraction following osseous crown lengthening. The remaining
buccal contours of teeth 13, 12, 2,1 and all the lingual contours,
were prepared using laser troughing setting. With this technique
we were able to take the final impression easily with good
moisture and bleeding control, since the newly re-contoured
tissues did not have to be disturbed.
Gingival recontouring
Photo at cementation appointment
Osseous reduction to create biological width Crown preparation and troughing for

on page 77
from page 74
The remaining time was spent on temporization, which due
to lack of lead time and preparation had to be done chair-side,
using Luxa-temp Bisacryl Automix temporary acrylic material,
by DMG America. The temporary bridge consisted of
six splinted crowns due to time constraints. The patient was
scheduled to return in two weeks to receive her final Lava
Zirconia crown restorations. A1 Vita shade guide color was
chosen to blend well with the posterior crowns, fabricated
At the final insertion appointment, the temporary acrylic
bridge was removed and the gingival tissues appeared healthy.
There was no bleeding and normal probing depths of 1-2mm,
were measured. The interdental papillae appeared slightly
blunted, as a result of having splinted temporary restoration
for the past two weeks and the patient’s inability to access
interdental spaces with proper oral hygiene. The six crowns
were individually cemented using Rely-X luting resin modified
glass ionomer cement by 3M. The patient was thrilled
with the result (Fig. 7a, 7b), more so after she was reassured
that the blunted papilla was a temporary effect that would
correct itself after resuming regular brushing and flossing,
over the next few weeks. Upon our next examination of the
patient, one year later, the papilla did indeed completely fill in
the interdental spaces and the gingival contours were healthy
and stable at the level established during the osseous crown
lengthening surgery. Five years later, the patient remains extremely
happy with her decision to have this cosmetic rehabilitation
done. The crown restorations and gingival contours of
anterior teeth remain stable and healthy (Fig. 8a, 8b).
In complicated aesthetic cases, such as this one, a successful
outcome depends upon a number of factors: patient’s compliance
with the prescribed regimen of home care and proper
planning and scheduling of all phases of treatment; training
and skill of the dentist; respecting periodontal health; and
the very important concept of biological width. Once a proper
diagnosis is made, there are many treatment modalities that
can be used to accomplish the change in gingival margin
and osseous position. Laser technology can offer advantages
which are not available with conventional methods, namely
better visibility due to bleeding control, faster healing and less
post-operative discomfort, due to the micro-invasive technique
and reduced inflammation.11 A thorough understanding
of laser-tissue interactions and mechanisms of action is crucial
in achieving good outcomes. For example, studies comparing
wound healing from a scalpel vs. Er,Cr:YSGG laser vs. diode
laser incisions observed more acute inflammation and tissue
Photo 1 year post-op
Photo 5 years post-op

78 oralhealth APRIL 2017
damage in diode laser group, as compared to the Er,Cr:YSGG
or scalpel. Diode lasers, although very common in a lot of
dental offices due to their affordability, have more thermal
side effects. Caution must be exercised when diode lasers are
used in close proximity to the hard tissues, such as teeth and
bone. In fact, diode lasers should be restricted to soft tissue
procedures only. However higher healing potential and cell
proliferation was found in both diode and Er,Cr:YSGG lasers,
as compared to scalpel incision.12 Another study compared
scalpel vs. Er,Cr;YSGG laser vs. CO2 laser and found more
ulcerations, higher level of inflammatory mediators and
slower healing at two weeks in the CO2 group. Although,
CO2 laser has better hemostatic ability, it resulted in greater
tissue damage and inflammation than Er,Cr;YSGG laser or
scalpel. Waterlase technology is advantageous in surgery due
to low inflammatory response and minimal tissue damage.13
Er:YAG 2940nm laser, a close relative of Waterlase
wavelength, has been shown to produce more pronounced
revascularization, fibroblast proliferation and less inflammatory
infiltrate than CO2 laser and mechanical burr9,14 and
less callus formation than saw osteotomy.15 It is quite clear
that the decision regarding which laser wavelength to use in
cosmetic applications, is of crucial importance. Training to
use the laser properly and experience in observing the desired
laser-tissue interactions is essential to treatment success and
patient satisfaction.
Cosmetic rehabilitation cases require from the dental practitioner
a high level of skill and continuing education, and from
the patient, a high degree of compliance. Laser technology can
help bridge the gap between the patient’s desire to have work
done quickly and with fewer visits, shorter healing times and
less discomfort, and the dentist’s need to follow sound biological
principles and accepted techniques to achieve the best
possible, predictable and long lasting cosmetic restorations. OH
Oral Health welcomes this original article.
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rationale, and treatment planning considerations. Pract Proced
Aesthet Dent 2004;16(10):769-78
2. Garguilo AW, Wentz FM, Orban B. Dimensions and relations of the
dentogingival junction in humans. J Periodontol. 1961; 32:261-67
3. Maynard JG, Wilson RD. Physiologic dimensions of the periodontium
significant to the restorative dentist. J Periodontol.
4. Wilderman MN, Pennel BM., King K, Barron JM. Histogenesis of repair
following osseous surgery. J. Periodontol, 1970; 41(10): 551-65
5. Lanning SK, Waldrop TC, Gunsolley JC, Maynard JG. Surgical
crown lengthening: evaluation of the biological width. J Periodontol
2003; 74(4): 468-74
6. Pontoriero R, Carnevale G. Surgical crown lengthening: a
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that occur in the jaws of rabbits following perforation by
an Er,Cr:YSGG laser. Lasers Med Sci 2005; 20:21-27
9. Pourzarandian A, Watanabe H, Aoki A, Ichinose S, Sasaki KM, Nitta
H, Ishikawa I. Histological and TEM examination of early stages of
bone healing after Er:YAG laser irradiation. Photomed Laser Surg
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K. Effects of Er,Cr:YSGG laser irradiation on canine mandibular
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12. Jin JY, Lee SH, Yoon HJ. A comparative study of wound healing
following incision with a scalpel, diode laser or Er,Cr:YSGG laser in
guinea pig oral mucosa: A histological and immunohistochemical
analysis. J Acta Odontol Scandinav 2010;68(4):232-38
13. Ryu SW, Lee SH, Yoon HJ. A comparative histological and immunohistochemical
study of wound healing following incision with
a scalpel, CO2 laser or Er,Cr:YSGG laser in the guinea pig oral
mucosa. J Acta Odontol Scandinav 2012;70(6): 448-54
14. Sasaki KM, Aoki A, Ichinose S, Yoshino T, Yamada S, Ishikawa
I. SEM and Fourier transformed infrared spectroscopy analysis
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2002;73(6): 1-10
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Losert U. Er:YAG and Ho:YAG laser osteotomy: the effect of laser
ablation on bone healing. Lasers Surg Med. 1994;15(4):373-81
Dr. Marina Polonsky DDS, MSc is
a gold medal University of Toronto
’99 graduate, she maintains
private general practice in Ottawa,
Ontario with focus on multi-disciplinary
treatment utilizing lasers of
different wavelengths. She holds
a Mastership from World Clinical
Laser Institute (WCLI), Advanced
Proficiency Certification from
Academy of Laser Dentistry (ALD)
and Master of Science in Lasers in
Dentistry from RWTH University in Aachen, Germany.