Hi Mary- the laser in most advertised lasers is nothing but a bright light that does very little to change the colour of your teeth. The only exception is when an actual diode laser is used together with whitening gels, it can break down stubborn antibiotic discolouration a little faster. At our studios in Westfield London, even though we have an actual laser whitening system, it is not the one we recommend most of our patients, as the results tend to be better for a combination of a whitening treatment done by us followed by home gels used 15 minutes daily for a week to counter the hydration darkening that happens afterwards as mentioned by Dr Rinkin. Even with these methods some fade back will occur over time, and top up treatments should be done (15 minute home gels) every 6 months or so.
Hi Mary Teeth whitening is a popular and effective treatment that can whiten brighten and transform any smile - we offer Zoom (worlds most widely used) and Enlighten (guaranteed brightest shade) for excellent results and happy smiling clients - for more on our clinic and our teeth whitening see this link http://www.traceybell.co.uk/smilescription/whitening.html
The results for "laser" tooth whitening Is good but most of The Time it will not last long as The whitening effect Is mainly due to dehydration of The Teeth. As soon as they hydrate in a few weeks/months the shade can return close to where it was before. As a cosmetic dentist I would advise enlighten tooth whitening for the best results and longevity.