Dr Arti Hindocha: Tooth Whitening Protocols During Aligner Treatment. Part Two of a Two-Part Series

In part two of a two-part blog series, Consultant Orthodontist Dr Arti Hindocha discusses her own tooth-whitening protocols and investigates the feasibility of using aligners instead whitening trays for tooth whitening. 

As the orthodontic industry sees a rise in demand for aligners and whitening, it seems there’s never been a better time to understand whitening and aligner combined treatment packages for adult patients. Whitening is being requested more frequently, especially by orthodontic patients (Slack, et al 2013). Davis et al. (1988) reported that 88% of orthodontic patients asked for whitening during or after their treatment.

Whilst part one discussed the best times to offer whitening and attachments during aligner treatment, part two, reveals the whitening protocols I follow, with success, and answer some of the questions commonly asked by dentists and orthodontists who are just getting started on their journey to offering tooth whitening and aligner packages.

Can patients whiten their teeth using an aligner instead of a whitening tray?

Conventional whitening trays incorporate reservoirs for the whitening agent, yet the close fit of a clear aligner, especially towards the end of treatment, leaves little room for a whitening gel. This is why it is said aligners are not suitable for placement of the whitening gel. However, some studies have shown that bleaching using non-scalloped and non-reservoir trays are safe and effective (Haywood et al., 1993; 2008; Javaheri et al., 2000; Miller et al., 2000).

Oliverio et al., (2019) carried out a study to investigate the feasibility of using aligners instead of whitening trays. They state, “SEM analysis indicated that the whitening agents had no effect on the F22 aligner material, because the microfilamentous structure was covered by a layer of organic material. Although some surface irregularities were visible at high magnifications, these appear to have been caused by the heat applied during the gilding process, rather than by chemical degradation. Striations that probably resulted from normal cleaning were also visible.

I believe you should spend time teaching and showing your patient how to apply the whitening gel, appropriately and sparingly, to the middle of the labial surface of the teeth in question of the aligner. I explain how to avoid leaking of the gel on to the gingivae and the gel should absorb effectively into the tooth. I advise patients to whiten premolar to premolar so there is no wastage of bleach on the posterior teeth. I spend time showing a patient how to apply the gel into their aligners and supplement the verbal instructions with written instructions. Ensure you take before and after photographs, record the shade of the tooth. Record the brand of whitening gel, % carbamide/hydrogen peroxide, protocol for delivery and instructions given for managing sensitivity. I provide a separate consent form for the patient to sign. Review your patient, document your maintenance protocol and store your consent form with the patient file.

What percentage and type of bleaching gels do you prescribe?

At-home whitening procedures can provide excellent results, often better than in practice treatment. (Zekonis, et al., 2003). Moreover, whitening agents that can be applied at home are associated with fewer adverse effects, as they generally contain lower concentrations of the active peroxide ingredient (Vaz et al., 2016). The key factors to consider are the concentration of whitening agent, and the length of time in contact with the teeth (Suleiman et al., 2004; Leonard et al., 1998).

The two most commonly used active ingredients for tooth bleaching are carbamide and hydrogen peroxide. The gold standard recommendation is to start with 10% carbamide peroxide (CP). Using 10% CP over 14 days for 8 hours at night, means tooth whitening occurs during a longer and albeit slower process. It is said that the effect of tooth whitening will last longer; overall being better for teeth. Additionally, when done overnight, compliance tends to be higher.

Therefore, due to the studies and the gold standard recommendation, I stick to 10% CP tooth whitening gels. If a patient wishes to maintain their result they can use 16% CP, over a shorter concentrated time period, 3- 5 nights, up to 3 times a year. However, there is greater chance of sensitivity in some cases.

Why is carbamide peroxide said to help reduce caries
and periodontal disease incidences?

Urea breaks down into byproducts such as C02, ammonia and strong free radicals that are key in lightening organic pigments, (D’Arce et al.,2013). Urea causes a transient increase in oral pH, neutralising saliva and contributes to a reduction in plaque formation which then said to reduce the incidence of decalcification and caries. This elevation in pH reduces the rate of caries just two hours after application. (Greenwall & Greenwall., 2017)

Additionally, hydroxyl radicals have a positive effect against bacterial membrane lipids and DNA, actually stimulating bacterial cell death. Moreover, by altering plaque microflora, debridement properties of released peroxides are achieved by CP, thereby increasing oxygen availability to promote gingival tissue healing. (Zinner et al., 1978).

Creating a patient centric approach

A systematic review named “The Effectiveness of Dental Bleaching during Orthodontic Treatment with Clear Aligners” (Khashashneh et al., 2022) concluded that tooth bleaching using clear aligners can be a safe treatment modality that would result in no harm to the gingivae when performed under professional supervision. At home bleaching popularity is attributed to its efficiency, lower cost, feasibility, and reduced adverse effects such as tooth sensitivity and soft tissue burns.

Patients often do have different preferences with their tooth whitening, and sometimes aligner attachment protocols for a variety of reasons. Offering the option to choose when they have aligner attachments may help motivate them to keep with their treatment routine, and ultimately look after their oral health. Working in a holistic way that accommodates a patient’s wishes requires a vigilant approach to consent and excellent communication. It is important your patient fully understands the benefits and risks associated with each protocol.


The views stated in this article are the views of Dr Arti Hindocha

Arti is working in partnership with DB Orthodontics to raise awareness of good practices for GDPs and orthodontists carrying out both fixed and aligner treatments, as part of a thorough care plan. Her recent presentation “Interproximal Reduction: Best Practice in Easy Slices” offers a comprehensive guide to IPR, including the benefits of a minimally invasive approach. 

Other articles from Dr Arti Hindocha:

About Dr Arti Hindocha  

BDS(Hons) MJDF RCS (Eng) MClinDent M.Orth RCS(Eng) FDS Orth RCS (Eng) C.I.L.T

Arti Hindocha qualified with Honours from King's College London (2009). She specialised in orthodontics at Eastman Dental Institute and Kettering General Hospital obtaining her MClinDent (UCL) on intra-oral scanning and M.Orth from the Royal College of Surgeons England (2015, 2016). She completed a further two years of higher orthodontic training at the Royal London Hospital and William Harvey Hospital; qualifying as a consultant in 2018, with her Fellowship in Orthodontics from the Royal College of Surgeons. She is currently a consultant orthodontist at Kettering General Hospital and works in 2 private practices in Wimpole Street and Northampton. She is passionate about teaching undergraduates and postgraduates, in her free time she supports and mentors GDPs who have an interest in orthodontics.She lectures locally, regionally and internationally; lectures feature topics such as Interproximal reduction, Autotransplantation, Ectopic teeth, IOTN and referrals.

Arti is currently Secretary of the European Federation of Orthodontic Specialists Association (EFOSA). She will be part of the Consultant Orthodontic Group committee (British Orthodontic Society) from 2023. She has been President of the European Postgraduate Student Orthodontic Society (EPSOS), Postgraduate Representative on the Royal College of Surgeons Board. She is a member of the British Orthodontic Society, British Lingual Orthodontic Society, and the European Orthodontic Society.



Slack, M.E.; Swift, E.J. Jr.; Rossouw, P.E.; and Phillips, C. (2013) ‘Tooth whitening in the orthodontic practice: A survey of orthodontists’, Am. J. Orthod. (143), (4 Supp), pp 64-71. Available at: 10.1016/j.ajodo.2012.06.017. (Accessed 12 December 2022).

Davis, L.G.; Ashworth, P.D.; and Spriggs, L.S. (1998) ‘Psychological effects of aesthetic dental treatment’, J. Dent. (26), pp 547-556. Available at: DOI: 10.1016/s0300-5712(97)00031-6. (Accessed 12 December 2022).

D’Arce, M.B.F., Lima, D.A.L., Aguiar, F.H.B., Bertoldo, C.E.S., Ambrosano, G.M.B. and Lovadino, J.R., (2013). ‘Effectiveness of dental bleaching in depth after using different bleaching agents’. Journal of Clinical and Experimental Dentistry5(2), p 100. Available at: DOI: 10.4317/jced.51063. (Accessed 12 December 2022).

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Available at:
https://static1.squarespace.com/static/5dc43d56f1a40f72ec167c68/t/5e29aff778c38064efcb5f19/1579790329309/Carbamide-Peroxide-and-its-use-in-Oral-Hygeine-and-Health.pdf . (Accessed 12,2022).

Haywood, V.B.; Leonard, R.H.; Jr Nelson, C.F. (1993) ‘Efficacy of foam liner in 10% carbamide peroxide bleaching technique.’ Quintessence Int., (9), pp 663–666.

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Khashashneh, M., Ratnayake, J., Choi, J.J.E., Mei, L., Lyons, K. and Brunton, P.A. (2022). ‘The Effectiveness of Dental Bleaching during Orthodontic Treatment with Clear Aligners: A Systematic Review’. Applied Sciences, (12), p 11274. Available at: https://www.mdpi.com/2076-3417/12/21/11274. (Accessed 12 December 2022).

Miller, M.B.; Castellanos, I.R.; Rieger, M.S. (2000) ‘Efficacy of home bleaching systems with and without tray
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Vaz, M.M.; Lopes, L.G.; Cardoso, P.C.; Souza, J.B.; Batista, A.C.;Costa, N.L.; Torres, E.M.; and Estrela, C. (2016) ‘Inflammatory response of human dental pulp to at-home and in-office tooth bleaching’, J. Appl. Oral Sci. (24), pp 509-517. Available at: https://doi.org/10.1590/1678-775720160137. (Accessed 12 December 2022).

Zekonis, R.; Matis, B.A.; Cochran, M.A.; Al Shetri, S.E.; Eckert,G.J.; and Carlson, T.J. (2003) ‘Clinical evaluation of in-office and at home bleaching treatments’, Oper. Dent. (28), pp 114-121.

Zinner D.D., Duany L.F., Llorente M, (1978). ‘Effects of urea peroxide in anhydrous glycerol on gingivitis and dental plaque’. J. Prev. Dent. (5), pp 38-40. 


About DB Orthodontics

It is our company mission to become a global leader in orthodontic and laboratory supplies. With over 45 years of experience in orthodontics, we recognise the importance of quality, service and innovation. Working to ISO13485 standards we strive for perfection in all that we do, from unique product design to the excellent service provided by our dedicated customer service and sales teams. We are continually developing our product range, designing innovative products through consultation with leading orthodontists from the world, to ensure that our products meet the high standards expected by today’s practitioners.