This is an extremely good question. There are a number of ways to lighten teeth, but most don’t work well for a patient desiring very white and bright teeth especially when a patient has only one or two darkened teeth anteriorly. This occurs when a patient has had one or two teeth that have had prior root canals and the teeth involved have gradually darkened.
In this instance, although I could try internal bleaching, most of the time I opt for fabrication of porcelain veneers or full crown restorations. One of the best techniques is Porcelain veneers, since this doesn’t involve much tooth reduction and it leaves the lingual surfaces mostly intact. This can be important in the long run, because anterior teeth that have had endodontic treatment may have significant tooth structure missing and are more vulnerable to fractures. Although some dentists routinely recommend post and core and crowning for these teeth, I do not always feel this is the best treatment option. Each patient’s situation should receive careful consideration before their optimal treatment is chosen.
The difficulty with choosing veneers, is that they work best when the tooth preparation is minimal, since significant enamel must remain for them to bond to, especially at their finish lines. If too much dentin is left exposed a laminate may be more prone either picking up stain, debonding or breaking, because dentin bonding is weak compared to enamel bonding.
The choice of a porcelain veneer option can present another problem for a restorative dentist and their ceramicist since a thin (.3-,5 mm veneer) doesn’t leave much room to hide the dark underlying teeth. Predictably masking the dark underlying tooth with a thin laminate can be tricky and require several attempts at fabricating a veneer, but when it does work it is really good dentistry, since crucial tooth structure will be maintained. Often custom try ins are required, including multiple visits to the dental lab for shade selection and custom staining. I have done cases like this that I am extremely proud of, but I must confess that often in these cases my profit has been thin or non-existent, considering the time I and my ceramicist have spent.
Porcelain veneers are not as predictable for older patients whom have a considerable amount of gingival recession, since most of the finish lines will be in dentin. For older patients I am much more likely to opt for full coverage restorations, since these are less dependent on bond strength than porcelain veneers. Also, full coverage restorations can work well when more significant tooth reduction is required, by the need to mask very dark grey tooth structure. Full coverage is also often a better choice for a fussy patient whom wants to be treated predictably and rapidly and doesn’t want to risk the difficulties posed by the choice of a porcelain veneers(harder to consistently match shades, harder to temporize, temporaries more likely to come loose repeatedly)
Accordingly each patients needs should be considered individually before the choice of restorative material and technique is made. There are many factors for a dentist to consider and the choice should be made in a thoughtful way. Patients are not optimally treated in a “cookie cutter manner” where every patient gets the same treatment.