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2 Advantages and Disadvantages of At-Home Whitening

2 Advantages and Disadvantages of At-Home Whitening

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J. Perdigão et al.



a



b



c



e

d



f



Fig. 6.7 (a) A 24-year-old patient suffered a traumatic injury to her tooth #8 (FDI 2.1). After 4 years,

her tooth became darker without any symptoms. The patient immediately visited her dentist who diagnosed pulpal necrosis. (b) A root canal treatment was performed and the lingual access preparation

restored with a resin-based composite material. (c) A special bleaching tray was fabricated to bleach the

discolored tooth following an at-home regimen. (d) A lower tray was fabricated and customized to serve

as stabilizer for the upper one-tooth tray. The lower tray was not used as a bleaching tray. (e) Patient

wearing the upper bleaching tray and the lower stabilizing tray. (f) After 5 days of at-home whitening

with 22 % carbamide peroxide gel (Whiteness Perfect 22 %, FGM) for 2 h twice daily



6



At-Home Tooth Whitening



6.3.1



109



At-Home Whitening in a Custom-Fitted Tray



Dentist-prescribed overnight bleaching with carbamide peroxide in a custom-fitted

tray has been shown to be the safest, most effective method of tooth whitening

(Haywood 2003; Matis 2004; Matis et al. 2009a).

Two clinical studies evaluated the 2-year effectiveness of tray whitening with carbamide peroxide (Swift et al. 1999; Meireles et al. 2010). In the first study, 29 patients

had their maxillary teeth treated with a 10 % carbamide peroxide gel nightly for 2

weeks. Teeth became eight shades lighter after 2 weeks of treatment when color was

measured with the Vita Classical A1-D4 shade guide (VITA Zahnfabrik H. Rauter

GmbH & Co. KG) organized by value (lighter to darker). Twenty-four patients were

recalled after 2 years. Teeth in 20 patients (83.3 %) had darkened an average of two

shades, which occurred during the first 6 weeks posttreatment. The lightening effect

remained statistically significant at 2 years. Overall, patients were satisfied with the

shade. In the second study (Meireles et al. 2010), 92 patients whitened their maxillary

anterior teeth with 10 % carbamide peroxide or with 16 % carbamide peroxide in a

custom-fitted tray for 2 h/day during 3 weeks. Shade evaluations were carried out at

baseline, 1 month, 6 months (Meireles et al. 2008b), 1 year (Meireles et al. 2009), and

2 year post-bleaching (Meireles et al. 2010). Although the 16 % carbamide peroxide

group showed some reversal of the whitening effect at 1 year (Meireles et al. 2009),

both treatment groups had the same median tooth shade 1 year after bleaching, which

was lighter than at baseline. At 2 years, the median tooth shade remained lighter than

at baseline for both carbamide peroxide concentrations tested.

Boushell et al. (2012) evaluated patients’ satisfaction and reported side effects of

at-home whitening with 10 % carbamide peroxide in a custom-fitted tray up to 17 years

posttreatment. Thirty-one participants who had completed clinical studies using 10 %

carbamide peroxide were contacted at least 10 years posttreatment. Patient satisfaction

with tray whitening was determined to last an average of 12.3 years posttreatment.

In case the patient perceives that there has been a color regression and is willing

to touch-up the teeth color, the original bleaching tray may be applied for 2 or 3

nights using the same 10 % carbamide peroxide gel. In case the tray no longer fits

the patient’s teeth as a result of recent restorations or extracted teeth, disposable

trays prefilled with 6 %, 10 %, or 15 % hydrogen peroxide gel (Opalescence Go,

Ultradent Products, Inc.) may be used 2 or 3 days. The respective manufacturer

recommends decreasing contact times with increasing hydrogen peroxide concentration. For the lowest concentration, the manufacturer suggests that patients wear

the disposable tray for 60–90 min daily, whereas for the highest hydrogen peroxide

concentration the recommended contact time is 15–20 min daily.

Patients often inquire if they need to refrain from a potentially staining diet

during and after at-home whitening. Current evidence from controlled clinical

trials suggests that coffee does not interfere with the outcome of whitening nor

does it affect tooth sensitivity (Rezende et al. 2013). Peroxide-based whitening

agents are effective in preventing any staining from coffee or red wine during the

treatment (Cortes et al. 2013). As a result, the need for a white diet during the

bleaching treatment has been challenged. A study determined whether a white



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diet is necessary by evaluating the effects of coffee, tea, wine, and dark fruits on

tooth whitening during the bleaching process (Matis et al. 2015). From five published studies, the authors concluded that a nonwhite diet was not significantly

associated with less tooth whitening, and there was only a weak positive association between tooth whitening and diet for subjects who consumed large amounts

of coffee/tea.

After the whitening regimen is completed, both coffee and red wine cause enamel

color change. Red wine, however, stains enamel more intensely than coffee (Cortes

et al. 2013).



6.3.2



Jump-Start Whitening



The objective of the jump-start technique is to boost the bleaching effect with the

in-office treatment, then improve color stability with the at-home component to

reach a more esthetic result compared to in-office bleaching alone (Deliperi et al.

2004; Matis et al. 2009b). Clinical evidence, however, does not support this assumption. Two recent clinical studies reported that the results of the combined in-office/

at-home technique were similar to those obtained only with the at-home technique

(Bernardon et al. 2010; Dawson et al. 2011). Therefore, the in-office component of

the combined jump-start technique does not improve the treatment outcome and

may be considered redundant. Nevertheless, this technique may motivate some

patients, as the whitening effect is visible immediately.

A more recent version of the jump-start technique is known as deep whitening

technique (Kör Whitening, Evolve Dental Technologies, Inc) (Sulieman 2008). This

technique currently includes three different modalities, according to the severity of

the discoloration: (A) 2 weeks of at-home overnight whitening with 16 % carbamide

peroxide, followed by one in-office whitening session with 34 % Tri-Barrel

Hydremide™ peroxide2; (B) in-office “conditioning” visit with 13 % Tri-Barrel

Hydremide™ peroxide in whitening trays followed by 3–4 weeks of at-home overnight whitening, and a final in-office whitening session with 34 % Tri-Barrel

Hydremide™ peroxide; (C) in-office “conditioning” visit with 13 % Tri-Barrel

Hydremide™ peroxide in whitening trays, followed by 6–8 weeks of at-home overnight whitening, and a final in-office whitening session with 34 % Tri-Barrel

Hydremide™ peroxide. All three methods require periodic at-home maintenance

after the treatment.

Currently, there is no independent scientific evidence to back the use of the

so-called deep whitening technique.



2



Hydremide is a trademark by Evolve Dental Technologies, Inc. Tri-barrel hydremide peroxide is

1 barrel of hydrogen peroxide gel, 1 barrel of carbamide peroxide gel, and the third barrel contains

an activator. The term hydremide derives from combining HYDROgen (peroxide) with carbaMIDE

(peroxide).



6



At-Home Tooth Whitening



111



The trays used in the deep bleaching technique are specially made trays (Kurthy

2001). As per the respective manufacturer, these trays provide better sealing than

conventional bleaching trays, enabling the whitening agent to be active all night as

opposed to other tray whitening methods (Kör Whitening 2015). The manufacturer’s website also states: “Clinical Research associates as well as other researchers

have found that whitening gel in conventional whitening trays is only strongly active

for 25–35 minutes. This is due to rapid contamination of the whitening gel by

saliva.” However, this statement is not supported by independent research. It has

been shown that hydrogen peroxide releases all of its peroxide in 30–60 min, with a

quick decline, while carbamide peroxide releases about 50 % of its peroxide in 4 h,

then experiences a slow decline (Haywood 2005).



More than 50 % of the carbamide peroxide active agent is available after

2 h. The percentage of carbamide peroxide recovered from tray and teeth is

10 % at 10 h (Matis et al. 1999).



The use of light sources to allegedly activate the peroxide during the in-office

component of the jump-start technique has been used in many dental offices.

According to Christensen (2003), “all whitening methods are successful to some

degree” but “the use of lights with bleaching has been mainly a marketing tool.”



6.3.3



Over-the-Counter (OTC) Whitening



Sales of OTC bleaching products have increased dramatically in recent years (Chap.

1), driven not only by their lower cost compared to professional tooth-whitening

techniques but also by strong consumer demand for esthetic dental care and easy

access through online auctions and e-commerce sites. Additionally, OTC bleaching

products are easy to use and convenient for the patient (Kugel 2003). Concentrations

as high as 44 % carbamide peroxide are available from online auctions sites and

retailers. Non-dental options are the latest trend, including mall kiosks, salons, and

spas. More recently, whitening has been performed in passenger ship cruises (ADA

Council on Scientific Affairs 2010).

How does the efficacy of OTC whitening products compare to that of the dentistprescribed at-home whitening? While there are many studies comparing OTC whitening with dentist-prescribed whitening, there are only a few independent clinical

studies (Serraglio et al. 2016). A study (Bizhang et al. 2009) measured tooth shade

with spectrophotometry and concluded that 6 % hydrogen peroxide whitening strips

applied twice a day for 30 min each for 2 weeks are not as effective as at-home

whitening with 10 % carbamide peroxide overnight for 2 weeks. Kishta-Derani

et al. (2007) evaluated four paint-on films self-adhering solutions that are brushed

on the tooth surface. These paint-on films contained hydrogen peroxide, sodium

percarbonate or carbamide peroxide. Two of the paint-on films did not result in any



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significant whitening effect after 2 weeks of daily application. The results obtained

with OTC whitening are not as pleasant and the procedure is not as safe as those

methods prescribed by a dental professional (Haywood 2003). For similar concentrations of hydrogen peroxide, OTC bleaching strips cause more gingival irritation

and tooth sensitivity than at-home tray whitening, as discussed in Chap. 4.

Given that OTC whitening products are not custom-fitted to the patient’s mouth,

they are not the ideal vehicle for the application of peroxide-based gels. Ill-fitting

trays may result in soft tissue injury, poor patient compliance, and malocclusion

problems (Kugel 2003).



6.4



At-Home Whitening with a Custom-Fitted Tray

Supervised by a Dental Professional



6.4.1



Treatment Plan



The correct diagnosis of the origin of the discoloration is critical, as different treatment options lead to different clinical outcomes. It is, therefore, imperative that the

dental professional understands the etiology of each specific tooth discoloration

case to be able to diagnose and prescribe the proper treatment for each patient.

Please refer to Chap. 1 for further details.

A full-mouth exam and recent periapical radiographs of the anterior teeth are

essential during the diagnostic appointment. Intra-oral photographs are extremely

valuable to document the pretreatment tooth color for future comparisons and to

include in the patient’s record. Pulp testing is always necessary for single-tooth discolorations. Patient must be informed that existing anterior esthetic restorations, including porcelain and resin-based composites, will not lighten with bleaching agents,

except for superficial extrinsic stains (Fig. 6.8). These restorations must be replaced

after the whitening treatment is completed to ensure an acceptable esthetic outcome.

Additionally, patient must also be informed that amalgam restorations that come in

contact with the bleaching gel may generate a “greening effect” of the tooth structure

in areas immediately adjacent to the amalgam material (Haywood 2002).



Fig. 6.8 Existing resin-based composite

restorations on teeth #8 (FDI 1.1) and #9

(FDI 2.1) after at-home whitening of the

maxillary arch with 10 % carbamide

peroxide with potassium nitrate and

sodium fluoride (Opalescence 10 % PF,

Ultradent Products, Inc.) in a custom-fitted

tray for 3 weeks



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At-Home Tooth Whitening



113



Haywood (2003) defined nightguard vital bleaching as a three-step technique:

1. Whitening material, which is usually a thick peroxide-based gel

2. Application prosthesis, currently known as the bleaching tray

3. Treatment regimen

Haywood (2003) suggested that wearing a tray on only one arch might improve

patient’s compliance, as patient can directly observe the color change in one arch

compared to the arch that is not undergoing treatment. Additionally, the interocclusal thickness of both maxillary and mandibular trays may exacerbate TMJ disorder

symptoms (Robinson and Haywood 2000).



6.4.2



Whitening Material



Carbamide peroxide in concentrations between 10 and 22 %,3 and hydrogen

peroxide in concentrations from 4 to 8 % have been used for at-home bleaching

for different periods of time (Joiner 2006; Meireles et al. 2008b; Matis et al.

2009a). A recent systematic review and meta-analysis of at-home whitening

concluded that carbamide peroxide results in a slightly better whitening efficacy than hydrogen peroxide when applied in a custom-fitted tray (LuqueMartinez et al. 2016).

The bleaching agent for at-home application that has been more frequently scrutinized in the dental literature is 10 % carbamide peroxide (Matis 2004). Chemically,

carbamide peroxide is a crystalline material containing a molecule of urea complexed with a single molecule of hydrogen peroxide – 10 % carbamide peroxide

contains approximately 3.3–3.5 % hydrogen peroxide (Cooper et al. 1992; Sulieman

2008; ADA Council on Scientific Affairs 2010). Carbamide peroxide is preferred

over hydrogen peroxide because it is more stable than hydrogen peroxide, providing

a nonaqueous formula of available hydrogen peroxide (Fischer 1995).

Current carbamide peroxide bleaching gels contain glycerin as a humectant and

flavor enhancer; and a thickener, usually a polymer (Carbopol,4 The Lubrizol

Corporation). Carbopol polymers are cross-linked high molecular weight homoand copolymers of acrylic acid, therefore containing active carboxyl groups. These

polymers are slightly acidic, which lowers the pH of the bleaching gel. Accordingly,

bases such as sodium hydroxide may be used to make the gel less acidic. Similar

thickeners and bases are also used in the composition of hydrogen-peroxidecontaining OTC bleaching strips.



3



The chance of a mismatch between the advertised concentration and the actual concentration is

very high (Matis et al. 2013).

4

Carbomer 934P or Carbopol 934P (The Lubrizol Corporation) is primarily used in commercially

available oral formulations, including bleaching gels for tray whitening.



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