Tooth whitening for the under-18-year-old patient (2024)

The GDC guidance mentioned previously states that products containing or releasing 0.1–6% hydrogen peroxide can be used in under-18 patients, only 'for the purpose of treating or preventing disease'.⁴ Guidance on the indications and conditions for adolescent bleaching have been listed in Box 1.

Some may suggest that discolouration may not fall under the classification of disease, however, it is prudent to understand the psychological and psychosocial effects associated with discolouration^30,31 and the emotional effect on a child resulting from delayed treatment of the discolouration.³² Negative self-image due to a discoloured tooth or teeth can have serious consequences on adolescents. As such, treating discolouration and disease may aid in prevention of bullying and associated or resulting mental health conditions such as depression and suicide.³³ Furthermore underlying enamel quality or quantity defects commonly associated with the discolouration also renders the classification of disease appropriate.

It is essential that all treatment options are provided to the patient and parents seeking dental bleaching, including the option of no treatment. All risks and benefits associated with bleaching must also be discussed before commencing treatment and consent appropriately obtained. It should be expressed that further restorative treatment may be required post bleaching, for example microabrasion, resin infiltration and composite bonding where large enamel surface defects exist.^12,34

Various factors relevant to the patient's discolourations must be considered when determining the need and urgency for bleaching in the under-18 patients. Some of these are listed in Box 2.

Detailed history taking, initial examinations and appropriate radiographs are essential for accurate diagnosis, treatment planning and identification of risk factors and oral pathology. It is essential to identify any restorations in the aesthetic zone and explain to the patient that post bleaching these may no longer be a matching shade and thus are likely to require replacement.³⁵

Furthermore, discolouration, particularly intrinsic stains, may not simply be an aesthetic problem and bleaching may not be the appropriate or the best choice for treatment.¹⁴ This will be discussed later in the article.

Bleaching treatment for the adolescent patient and patient groups is listed in Box 1.

Severe and moderate discolouration

As discussed previously, the psychosocial effects of discolourations can be extreme. Severe discolouration can result from numerous aetiologies, including but not limited to:

• Fluorosis (Figs 1, 2 and 3)

  b) Labial view of the incisors following three weeks of bleaching. c) Labial view of maxillary incisors following ten weeks of bleaching

  Full size image

• Discoloration caused by antibiotics or resulting from a child's complex medical history (Fig. 4).

  b) Labial view of teeth in occlusion following successful treatment with bleaching and composite replacement

  Full size image

  b) Labial view of the result post bleaching and microabrasion treatment

  Full size image

  This was believed to have resulted from amoxicillin which was administered to the child at a young age

  Full size image

Fluorosis can be effectively bleached, as shown in Figures 1, 2 and 3. Bleaching is most effective in class 1 to 3 of the tooth surface index of fluorosis and as such alternative treatment may be required for patients with severe flurorosis.³⁶

Severe discolouration may require prolonged bleaching.¹⁴ This can be seen in Figures 1a and 1b, whereby after three weeks of bleaching treatment, the brown discolouration had reduced, however, had not completely resolved. Bleaching treatment was prolonged for an additional seven weeks and this eventually resulted in complete resolution of the brown discolouration (Fig. 1c). The patient was delighted with the final result, despite the presence of the white lesions and as such chose no further treatment.

Enamel conditions

A range of enamel conditions result in discolouration and can be effectively treated with bleaching. These include but are not limited to:

• Amelogenesis imperfecta (see hereditary section)

• Post traumatic opacities

• Idiopathic opacities

• Chronological hypomineralisation

• White markings or puffs on the lines of enamel maturation.

White lesions

White spot lesions have numerous aetiologies.³⁷ Some markings are chronologic in nature and appear as white lines that follow deposition of enamel such as amoxicillin or high temperature defects³⁸ which are shown in Figure 4. Bleaching treatment whitens the surrounding or background enamel of the white lesion, which reduces the contrast of the defect as demonstrated in Figure 5b. It has also been suggested that elevation of salivary Ph and flow rates following carbamide peroxide application³⁹ may alter the refractive index of the white spot by promoting remineralisation, however, further research is required.

Isolated white blemishes (Fig. 5a), can be aesthetically challenging for the young child and tooth bleaching or whitening is a simple way to eradicate these unsightly markings on the teeth. This may need to be followed by microabrasion or resin infiltration. In the patient illustrated in Figures 5a and b, a combination of bleaching using custom tray-applied 10% carbamide peroxide followed by resin infiltration was used to successfully to eradicate the white blemishes on the central incisors (Fig. 5b).

Original white spots may become more noticeable during bleaching treatment, as seen in Figure 1c. This is due to the bleaching material penetrating the weakest part of the enamel first, which is often the white spot. This commonly occurs during the first few days and is referred to as the 'splotchy stage' of bleaching.⁴⁰ The patient must be urged to persevere with the bleaching treatment to allow time for the bleaching material to dissipate equally throughout the enamel and allow efficient lightening of the background. The 'splotchy stage' must be described to the patient before treatment. This is essential for informed consent and to ensure compliance.⁴¹

White spots that are present following completion of bleaching treatment may become less noticeable two weeks post treatment, as oxygen dissipates from the tooth and especially the white spot defect, however further treatment may be required to mask the defect.³⁴

Brown and yellow staining

Isolated yellow and brown stains result from numerous aetiologies.¹² Fluorosis may result in brown blemishes as seen in Figures 1a, 1b and 1c. Brown stains can be removed 80% of the time by bleaching alone and as such, should be the first line of treatment for such conditions.⁴² Cases where bleaching does not completely remove brown staining should utilise additional microabrasion and bonding procedures.⁴³

Coronal defects

Coronal defects can present as discrepancies in tooth shape, size, position, proportion, shade and number. Bleaching often forms an integral part in management of aesthetics and can reduce the need for invasive restorations in the management of such cases. No better is this illustrated in use of bleaching, bonding and orthodontics as compared to the use of porcelain veneers and crowns. Furthermore, the use of bleaching to lighten the value of a tooth, can reduce the requirement for excessive reduction required for indirect restorations to mask discolouration appropriately. This enables the use of more translucent, multi-chromatic restorations, thus improving the outcome of such treatment modalities. Validation of bleaching in such circ*mstances is particularly noted in severe tetracycline discolouration.

Bleaching material can also improve the longevity of restorations in the anterior region, which may be failing due to exposure of restorative margins or due to discolouration of underlying tooth structure. Although bleaching materials have no effect on porcelain, they can successfully penetrate and bleach tooth structure beneath porcelain veneers.⁴⁴

As is true for all bleaching cases, further restorative treatment should be delayed for at least two weeks following the completion of bleaching. Bond strength to composites is reduced by 25–50% during bleaching,⁴⁵ however, returns to normal two weeks following treatment. This results from oxygen, in the enamel because of the bleaching material, inhibiting the set of resin tags in etched enamel. Over a two-week period, the oxygen dissipates out of the enamel thus returning bond strength to normal.

Oxygen present in enamel can also lead to incorrect shade taking and thus, shade taking should also be delayed by at least two weeks and up to six weeks in cases whereby exact shade matching is at a premium.

Molar incisor hypomineralisation (MIH)

MIH lesions often present as demarcated enamel opacities ranging in colour from creamy white to yellow/brown, as seen in Figure 6. It is well documented that children with MIH may suffer from a reluctance to smile or a lack of confidence due to the appearance of their teeth and thus may require treatment early to prevent this.⁴⁶ Bleaching has been reported to produce some improvement in MIH patients, especially with the yellow brown discoloured defects.⁴⁷

Teeth affected by MIH show inflammatory changes within the pulp⁴⁸ and as a result, sensitivity is more common among this group of patients. Therefore, adequate sensitivity prevention before undertaking bleaching treatment is required.

Hereditary factors

Several hereditary conditions can lead to white blemishes and white discolouration of teeth. These markings can be generalised for example in amelogenesis imperfecta (AI) patients (Fig. 7) or there can be a single isolated white mark or white blemish on a tooth. Depending on the severity, tooth whitening can be undertaken as the first option for this group of patients.

Hereditary conditions associated with defects in enamel and dentine include:

1. Hereditary conditions associated with defects of epithelial tissues:⁴⁹

• Congenital erythropoietic porphyria

• Ectodermal dysplasia

• Epidermolysis bullosa

• Tuberous sclerosis

2. Hereditary conditions associated with defects in mineralisation pathways:

• DiGeorge syndrome⁵⁰

• Vitamin D dependent rickets,⁵¹ Vitamin D resistant rickets,⁵² pseudovitamin D deficiency rickets⁵³

3. Dentinogenesis imperfecta⁵⁴

4. Amelogenesis imperfecta:⁵⁵

• Hypoplastic

• Hypomineralised: hypomaturation (including hypomaturtion-hypoplastic with tuarodontism) and hypocalcified

5. Cystic fibrosis⁵⁶

Bleaching has been shown to be successful in the minimal invasive treatment of hereditary conditions especially amelogenesis imperfecta⁵⁷ and dentinogenesis imperfecta.⁵⁴ This is extremely beneficial for such patients as preservation of existing enamel is crucial in such conditions. Sensitivity may also be an issue for patients with hereditary defects and adequate sensitivity prevention is required.

Traumatised/non-vital teeth

Discolouration associated with trauma or loss of tooth vitality can be very severe and range in colour from yellow, black, brown, purple and grey (as seen in Figure 8).

Haemorrhage of the pulp is the most common cause of discolouration after trauma. Blood enters the dentinal tubules and then decomposes leading to a deposit of chromogenic blood degradation products, such as haemosiderin, hemine, haematin, and haematoidin. Chromogenic degradation products also result from pulp necrosis.⁵⁸

Calcific metamorphosis may also results in discolouration and is commonly seen as early as three months after traumatic tooth injury. It is characterised by the deposition of hard tissue within the root canal space and a yellow discolouration of the clinical crown.⁵⁹

Discolouration may result from iatrogenic induced causes following treatment of the non-vital tooth. These include:

• Root canal cement or gutta percha in the coronal portion of the access cavity

• Remnants of the pulp and pulp horns following access cavity preparation⁶⁰

• Combining sodium hypochlorite (even at low concentrations) and chlorhexidine irrigation which may result in formation of brownish-red precipitates.⁶¹

It is essential that iatrogenic causes are appropriately identified and managed before commencing with bleaching treatment.

Discoloured teeth with a history of trauma should undergo vitality testing and if no previous radiographs have been taken, appropriate radiographic assessment should be undertaken to ensure appropriate treatment is undertaken prior to and post bleaching.⁶²

A single discoloured tooth which retains vitality, for example in calcific metamorphisis,⁵⁹ should not have elective root canal treatment undertaken. These patients should rather be provided with a 'single tooth' bleaching tray as seen in Figure 9 and bleaching agent applied externally, solely to the targeted discoloured tooth. This is because externally applied bleaching material diffuses readily through teeth and uniformly changes dentine shade throughout, regardless of depth.⁶³

There are several different non-vital bleaching techniques and these have been described elsewhere in the literature.^64,65 The author would recommend the inside/outside closed bleaching technique for the adolescent patient. This involves sealing 10% CP into the pulp chamber and providing the patient with a 'single tooth' bleaching tray, who continues bleaching externally at home. This technique allows for adequate cleaning of the pulp chamber without the associated risks of leaving the access cavity open and allows repeated frequent application of bleaching agent externally, thus allowing maximum whitening of the tooth without the patient returning to the practice.

Some may choose to utilise the inside outside open technique. This would involve leaving the access cavity open to allow frequent replacement of the bleaching agent intracoronally, which would otherwise become inactive up to ten hours post application. As mentioned previously, this is unnecessary due to the rapid penetration of bleaching material through the tooth from the external surface. Furthermore, this may also potentially jeopardise the root canal treatment, if the patient fails to keep the access cavity appropriately clean or fails to return in a timely fashion for the access cavity to be closed. As such, this technique should only be used on well-motivated patients who are excellent attenders and with excellent oral hygiene.

Systemic diseases

Numerous systemic diseases can lead to discolouration including but not limited to:

• Premature birth and low birthweight⁶⁶

• Diseases of the blood⁶⁷

• Neonatal jaundice

• Neonatal kidney and liver disease.⁶⁸

Antibiotics used to treat systemic infections, such as tetracycline,⁶⁹ amoxicillin³⁸ and ciprofloxacin can also lead to discolouration of teeth. The discolouration experienced as a result of systemic disease is most likely to be intrinsic in nature and, as such, requires prolonged bleaching. Tetracycline staining has been shown to require up to six months of prolonged custom tray-applied 10% CP bleaching to ensure a satisfactory effect.⁶⁹ This whitening effect has been shown to remain in 60 and 90-month follow up studies.^70,71