4622_200610PPAD_Gomes.qxd 11/7/06 11:03 AM Page A
Isabel Gomes, DMD* • Pedro Moura, DMD†
George Gomes, DMD‡ • Jorge Perdigão, DMD, MS, PhD§
Dental staining can either be extrinsic or intrinsic. designated by nightguard vital bleaching (NGVB), sug-
Tobacco, certain foods, and a selection of bev-
gested using 10% carbamide peroxide gel in a tray.6
erages are some of the materials responsible for extrin-
Carbamide peroxide rapidly dissociates into hydrogen
sic pigments that deposit on teeth. These deposits are
peroxide, the active element, and urea. The concentra-
easily removed through polishing with abrasive pastes
tion of carbamide peroxide used in the NGVB technique
or air-abrasion. On the other hand, intrinsic pigmenta-
has been slightly modified and may vary between 5%
tion occurs when certain substances are incorporated
and 22%. The NGVB technique does not result in a sig-
during the tooth formation (eg, tetracycline-staining,
fluorosis) or after the tooth formation is completed (eg,
endodontic cements, amalgam).1 This discussion pre-
sents a clinical case in which enamel microabrasion
A 23-year-old female patient presented with a chief com-
was combined with at-home whitening to improve the
plaint of discoloration (ie, pigmentation) on her maxillary
appearance of intrinsic staining of the maxillary cen-
central incisors. Sensitivity tests using an ice stick resulted
tral incisors. Taking into consideration that at-home whiten-
in a positive response that did not last longer than 5 sec-
ing with carbamide peroxide is conservative, safe, and
onds. The patient denied having taken tetracycline or
effective, it should be the first option for treatment of
fluoride supplements as a child, and did not recall
any dental trauma, or infection of the homologous
Hydrochloric acid (HCl) and hydrogen peroxide
deciduous teeth. Following clinical and radiographic
(H O ) have been used to remove intrinsic stains from
examinations, at-home whitening using a concentration
vital teeth, sometimes with the application of heat and/or
of 10% carbamide peroxide was prescribed to the
abrasive agents. Both are reported to be effective in
patient. The patient was then informed that in case the
eliminating pigmentation caused by fluorosis, trauma, or
tetracyclines.2 The enamel microabrasion technique uses
HCl and pumice to remove staining.3 Microabrasion has
been used to remove intrinsic staining with a depth lim-
ited to the enamel’s superficial layers.4 This technique,
however, results in the loss of superficial enamel due to
chemical dissolution. Ten consecutive 5-second appli-
cations of a suspension of 18% HCl with pumice removes
technique that used 10% carbamide peroxide in a
Figure 1. Preoperative facial view of the patient’s teeth
custom-made tray to whiten vital teeth.6 This technique,
showing significant discoloration in the anterior zone.
Vol. 18, No. 10
4622_200610PPAD_Gomes.qxd 11/7/06 11:03 AM Page B
Figure 2. Magnified view of the two central incisors. The Figure 3. View of the patient’s anterior maxilla following patient was prescribed an at-home bleaching plan to three weeks of at-home whitening with 10% carbamide whiten these teeth. peroxide. Figure 4. View of the maxillary central incisors following Figure 5. Postoperative facial view of the patient’s retracted enamel microabrasion. smile following at-home whitening of the mandibular arch.
pigmentation subsisted following NGVB treatment, a less
and #9(21) had nearly been eliminated and the teeth
conservative approach utilizing enamel microabrasion
were noticeably whiter (Figure 3). The patient did not
report experiencing any side effects. The residual pig-
Full-mouth custom-made trays were fabricated with
mentation was then limited to the incisal third of both
0.9-mm-thick Sof-Tray Classic Sheets (Ultradent Products,
incisors as mesiodistal darker bands.
South Jordan, UT). The trays were made without reser-
The patient agreed to undergo enamel microabra-
voirs,8,9 and the margins of the trays were trimmed at the
sion treatment following at-home bleaching. After isolat-
gingival line. The patient was instructed on how to use
ing the area with a rubber dam, a slurry containing 6.6%
the tray and how to apply the 10% carbamide peroxide
hydrochloric acid with silica particles (ie, Opalustre,
gel (ie, Perfect Bleach, Voco, Sunnyside, NY) for a period
Ultradent Products, South Jordan, UT) was applied on
of two to three weeks. Treatment of the mandible was
the incisal third of both incisors using chemical and
delayed so that it could serve as a point of reference.
mechanical abrasion. Opalustre was applied manu-
Preoperative and postoperative photographs were taken
ally, rubbed on for 10 to 15 seconds, and then thor-
(Figures 1 and 2), and the patient was advised to cease
oughly removed with water spray. This procedure was
treatment in the event any undesired effects occurred.
repeated three times, until the dark bands turned lighter.
Three weeks later, the brown pigmentation of teeth #8(11)
A neutral sodium fluoride gel (ie, Nupro, Dentsply
Vol. 18, No. 10
4622_200610PPAD_Gomes.qxd 11/7/06 11:03 AM Page C
Professional, York, PA) was applied for 4 minutes on
Reservoirs built into whitening trays are not mandatory
the microabraded surface. The teeth became dull with a
because the reservoirs do not result in better outcomes
milky appearance immediately following microabra-
sion treatment, and the brown pigmentation was elimi-
nated (Figure 4). After whitening the mandibular arch
with 10% carbamide peroxide for two weeks, the final
According to the literature, it is demonstrated that the first
photographs were recorded (Figure 5). In the present
option for the successful treatment of brown intrinsic den-
clinical case, the NGVB technique was the first treatment
tal pigmentation, of unknown origin in this case, is the
option performed, not only because the pigment was
most conservative approach—at-home whitening with
of unknown etiology, but also because the NGVB is a
10% carbamide peroxide. Meanwhile, if results are
conservative procedure backed by several studies in
not satisfactory, the patient’s aesthetic expectations may
which the results were very satisfactory, even in cases
warrant a more invasive treatment option, such as
where the pigmentation is known to be located in deep
microabrasion, direct bonding, or even porcelain veneers.
After having eliminated several etiologic factors, the
pigmentation observed in this clinical case was classi-
1. Nathoo SA. The chemistry and mechanisms of extrinsic and intrin-
sic discoloration. J Am Dent Assoc 1997;128 Suppl:6S-10S.
fied as idiopathic congenital pigmentation.10 Treatment
2. McEvoy SA. Chemical agents for removing intrinsic stains from
vital teeth. II. Current techniques and their clinical application.
options range from NGVB to a microabrasion followed
3. Croll TP, Cavanaugh RR. Enamel color modification by controlled
by increasingly more invasive techniques such as a direct
hydrochloric acid-pumice abrasion. I. Technique and examples. Quintessence Int 1986;17(2):81-87.
composite restoration to porcelain veneers. At-home
4. Croll TP. Enamel microabrasion: The technique. Quintessence
whitening with 10% carbamide peroxide is frequently
5. Tong LS, Pang MK, Mok NY, et al. The effects of etching, micro-
abrasion, and bleaching on surface enamel. J Dent Res
prescribed by dental professionals, yet not all view this
6. Haywood VB, Heymann HO. Nightguard vital bleaching.
technique as an option to remove brown stains, despite
Quintessence Int 1989;20(3):173-176.
7. Haywood VB. History, safety, and effectiveness of current bleach-
ing techniques and applications of the nightguard vital bleach-
The most frequent side effect of the NGVB technique
ing technique. Quintessence Int 1992;23(7):471-488.
8. Javaheri DS, Janis JN. The efficacy of reservoirs in bleaching
is dental sensitivity, which occurs in two thirds of patients,
trays. Oper Dent 2000;25(3):149-151.
9. Matis BA, Hamdan YS, Cochran MA, Eckert GJ. A clinical eval-
though it is more likely to occur if the patient has a his-
uation of a bleaching agent used with and without reservoirs. Oper Dent 2002;27(1):5-11.
tory of existing sensitivity, gum recession with exposed
10. Croll TP. Enamel microabrasion: Observations after 10 years.
J Am Dent Assoc 1997;128 Suppl:45S-50S.
cement, and infiltrated restorations or caries lesions.12
11. Haywood VB. Nightguard vital bleaching: Current concepts and
research. J Am Dent Assoc 1997;128 Suppl:19S-25S.
Sensitivity can be attenuated by interrupting the whiten-
12. Leonard RH Jr, Haywood VB, Phillips C. Risk factors for devel-
oping tooth sensitivity and gingival irritation associated with night-
ing regimen for a few days, reducing the number of hours
guard vital bleaching. Quintessence Int 1997;28(8):527-534.
13. Tam L. Effect of potassium nitrate and fluoride on carbamide per-
of contact of the gel with the teeth, or even by decreas-
oxide bleaching. Quintessence Int 2001;32(10):766-770.
ing the amount of gel in the tray.12 Some clinicians
*Assistant Professor, University of Lisbon School of Dentistry,
prefer to use whitening gels with fluoride ion and potas-
Department of Removable Prosthodontics, Lisbon, Portugal. Graduate Program in Operative Dentistry, School of Dentistry,
sium nitrate, which have been shown to reduce sensi-
ISCSEM. Dr. Gomes may be reached at [email protected].
tivity during treatment.13 The least frequent side effect is
†Assistant Professor, ISCSEM, Department of Operative Dentistry; Graduate Program in Operative Dentistry, School of Dentistry, ISCSEM.
Some methods of preventing the undesirable effects
‡Clinical Instructor, Post-Graduate Program in Operative Dentistry, ISCSEM; PhD Candidate, School of Dentistry,
on the soft tissue are avoiding direct contact between
University of Granada, Granada, Spain.
gel and the soft tissue by using more retentive trays,
§Associate Professor, University of Minnesota, Department of Restorative Sciences, Division of Operative Dentistry,
and trimming the margin slightly shorter of the tissue line. Minneapolis, MN.
Vol. 18, No. 10
Fixed-Income Holdings Per Currency As at 31 December 2002 Security Nominal amount (QC) Market Value (SEK) Clean Value(SEK) EUR Belgium Kingdom Government 5.50 2017-09-28 Italy Buoni Poliennali Del Tesoro 6 2031-05-01 7 169 309 285 6 958 443 680 GBP United Kingdom Government 9 2011-07-12 United Kingdom Government 5.75 2009-12-07United Kingdom Government 6.25 2010-11-