Which bleaching trays are most effective

 

In 2018 Everatt and Bretton reviewed the literature on whitening trays concluding there is only a limited number of clinical studies that discuss tooth bleaching. I have included their key findings in this article. 

 

Mizuhashi and Koide (2017) found that vacuum-formed appliances maintained material thickness, whilst pressure formed appliances obtained a better fit and were significantly improved by pressure forming equipment. At Ultralight we obtain excellent fit for your clients by pressure forming all our trays. 

 

Do bleaching trays need reservoirs or not? Matis et al (2002) showed there was little difference in results in terms of shade with or without reservoirs. The importance of using reservoirs is linked to how well the margins are sealed. Trays that are scalloped are inevitably more flexible and will allow more bleach to escape the tray, therefore requiring a larger amount of bleach present in a reservoir. Clinicians such as Kurthy (2016) advocate the use of reservoirs and finishing the tray exactly at the gingival margin. Haywood (2008) says that teeth bleach just as quickly without the reservoirs as they do with and they can reduce the tightness of the tray. So, it appears that using reservoirs remains mainly a personal choice/preference for each dentist rather than a proven clinical need. We are happy to provide reservoirs if you believe they are needed. 

 

There appear no cited references to the benefits of scalloping trays. Since 2013 laws in the UK restricted the use of higher concentration ‘in office’ bleaching, meaning the need for scalloped trays is no longer an issue in terms of gingival contact. Cowley et al 2012 found that a straight cut margin of approximately 2mm beyond the margin will give better stability. The additional flexibility that comes with scalloping a tray can be problematic in bruxism patients, as the tray is more prone to bending and emitting bleach compared to straight cut trays, and scalloping can be counterproductive in terms of patient comfort and tray stability. 

 

The study concluded that an optimal tray design should have a good peripheral seal around the gingival margin, be trimmed straight just beyond the gingival margin to improve seal and stability, and provide comfort and, therefore, increased compliance for the patient. 

 

Horror stories about bleaching trays on the internet mainly relate to diy home kits. As dentists you will be aware of the importance of encouraging your patients to use trays you prescribe as the home kits can be a false economy, particularly as the level of peroxide is too low. Haywood (2003) suggests that the effectiveness of whitening is greatly improved when the hydrogen peroxide is around 6%, and custom-made dental trays are used to hold the gel close to the teeth for a period of around two hours. Carey (2014) concurs and proposes that home-based bleaching (following manufacturers instructions) results in less tooth sensitivity than in-office bleaching. 

 

The main side effects of teeth whitening are increased tooth sensitivity and gingival irritation. As already highlighted gingival irritation can be eliminated/reduced by prescribing quality fitting trays. Sensitivity is also reduced with quality trays and using a sensitive toothpaste prior to treatment is something I have found helpful.  

At Ultralight we don’t claim to make the cheapest bleaching trays but the quality and fit of our products is recognised by many dentists and patients. We always offer a discount on the first trays you purchase from us and regular customers also receive discount on repeat orders. We have the facility to make bleaching trays to whichever specification or whitening system you prefer. 

 

As always, if you have any queries about this blog please contact me via our website or give us a call on 01937 588868. 

 

Giles Bradley