Choosing the shade of implant teeth: A1, A2 or BL1?

One of the most widely used guides for choosing a shade is the classical guide from the German manufacturer VITA. The guide consists of 16 shades and, as the manufacturer describes it, is divided into four families: reddish-brown shades from A1 to A4, reddish-yellow from B1 to B4, greyish from C1 to C4 and reddish-grey from D2 to D4. The letter shows the type of colour, and the number shows how intense and dark that type is. A1 is lighter than A2; A3.5 is darker than A3. This abbreviation is also what is written on the prescription that goes to the laboratory.

Names such as BL1 and 0M1 fall outside these 16 shades. VITA offers three additional shades called 0M1, 0M2 and 0M3 to determine the colour of whitened teeth. Ivoclar, for example, adds four bleach shades called BL1, BL2, BL3 and BL4 to its 16-shade A to D guide. These are shades that imitate the result after whitening. The question 'BL1 or A1?', which patients often ask about full-mouth fixed teeth, is really the question 'as if whitened, or like the lightest natural shade?'

Tooth colour is not just a single number. In colour science three separate properties are measured: lightness and darkness, the saturation of the colour, and the hue, that is, whether it leans towards yellow or red. In a study measuring the natural front teeth of 87 people, the colour of the tooth became progressively redder and more yellow from the biting edge towards the gum, while translucency decreased towards the root. The same study found that the red-green spread of the samples on the guide did not cover all natural teeth. A natural tooth is not a surface painted a single colour; it carries a transition, with a more translucent tip and a more saturated neck.

Age changes this picture. In the same study, the middle part of the tooth measured darker and more yellow as people got older. Cleveland Clinic explains this by the enamel thinning with age and more of the yellowish dentine beneath showing through. This is why, in a 60-year-old face, a very light tooth colour typical of a 20-year-old and a shade typical of people the same age do not create the same effect. With full-mouth fixed teeth, because the patient can choose any shade, this natural relationship with age becomes a conscious decision.

Studies looking at the relationship with skin tone do not give a one-directional result, and it is important to know this plainly. In a JADA study with 140 assessors, made up of dentists and non-dentists, skin and tooth lightness were altered in the same smile photograph. The assessors did not find the lightest tooth shade the most attractive; dark skin with very bright white teeth, and light skin with dark teeth, were found relatively unattractive. In an Italian study with 328 participants, A1, A2, A3 and A4 were compared, and A1 was found the most attractive regardless of skin tone. Both studies used a digitally altered smile photograph of a single woman, and the second did not test bleach shades; in other words, they support the conclusion that 'A1 is a light and well-liked shade within the natural guide', not the conclusion that 'the whitest shade suits every face'.

Remaining natural teeth narrow the decision. The NHS says teeth whitening can only lighten the colour of natural teeth and is not recommended for people with crowns, dentures or implants. Once a ceramic tooth has been made, it does not get lighter with whitening. If one whole jaw is going to be made on implants while your natural teeth remain in the opposing jaw, and you are thinking of whitening those teeth, the whitening should be done before the shade is chosen and the shade taken after the result has settled. The NHS also notes that whitening is not permanent and its effect can last about 3 years; as natural teeth darken again over time while ceramic teeth stay the same, the difference between them can grow.

With full-mouth fixed teeth, the colour decision is not limited to the teeth. In jaws with bone and gum loss, part of the bridge can be made in gum-coloured ceramic; this is called pink porcelain or artificial gum. A technique article published in the Journal of Prosthodontics says that pink ceramic can reduce the need for extensive surgical procedures to replace lost hard and soft tissue in the visible area of the upper jaw, but that matching the colour of pink ceramic to the existing gum is difficult, especially in patients whose gums show a lot when they smile. The gum colour is something chosen, just like the tooth colour.

How the material keeps its colour is a separate subject. In a meta-analysis combining laboratory studies, the colour and translucency of monolithic translucent zirconia did not change significantly under artificial ageing up to a certain duration; with longer ageing, however, clinically unacceptable changes were seen. These results come from laboratory conditions and cannot be translated directly into years in the mouth. In a laboratory study of acrylic teeth, conventional acrylic teeth showed a visibly noticeable colour change after 30 days in coffee; computer-milled acrylic teeth stayed more stable. A detailed comparison for choosing the material is in a separate guide.

The first list describes situations where light shades can sit without causing problems; the second describes situations where a very white shade is likely to look out of place in the face. The final decision is made by seeing the face, the lips and the light together.

Colour is not something you like in a catalogue and tick. The sequence below helps you make the decision according to your face and your mouth.

1. 1

   Decide about your natural teeth first

   If you will have natural teeth remaining in your mouth and you are thinking of whitening, do it before the shade is chosen. The NHS says whitening lightens natural teeth only; a ceramic tooth cannot be lightened later.

2. 2

   The right light

   In one study, the same observer chose shades for 100 people in daylight, under an operating lamp and with a hand-held colour-corrected lamp; the best match was achieved in colour-corrected light. The overhead dental chair light is not suitable for choosing a shade. Make your own assessment in daylight in front of a window too.

3. 3

   Shade guide and measuring device together

   In a meta-analysis that reviewed seven clinical studies and combined six of them, measurement with a spectrophotometer, a digital camera and a smartphone was found more accurate than visual selection with a shade guide; the colour measurement of an intraoral scanner, however, was not significantly better than the eye. The device supports the eye rather than replacing it.

4. 4

   A try-in with the face

   The shade sample is assessed not only at tooth level but together with the colour of the lips, skin and eyes, in a mirror and from talking distance rather than up close. Taking a photograph and looking again the next day can show whether a shade that seemed striking at first is overdone.

5. 5

   Gum colour and smile line

   If the full-mouth bridge will have pink porcelain, its colour is also chosen with a separate guide according to the existing gum. How much gum shows when you smile determines how much this transition will draw attention.

6. 6

   Put the decision in writing

   The chosen tooth shade, whether there will be pink porcelain and its colour, and the material to be used should be written on the prescription and in the plan given to you. With the conventional method, the colour can be tried in a temporary bridge used for months and revisited in the final bridge. At implant72, the implants and fixed teeth are completed in 3 days / 72 hours and the teeth fitted on day 3 are the final teeth; that is why the colour is tried in your face with the try-in teeth on days 1 and 2 and settled together before the final teeth are made.

A single method is not enough; the best result comes when several are used together.

The following are mistakes that both patients and dentists often make. Most of them can only be corrected once treatment is complete by making new teeth.

The colour you choose may not be the same on the day it is fitted and years later. Knowing whether it is the tooth itself or its surroundings that changes sets your expectations correctly.

1. The first days

   New teeth may look whiter or bigger than they are in the first days, because you are comparing them in the mirror with how you looked before. The eye gets used to them within a few days.

2. The first months

   As the gum heals, the transition between tooth and gum becomes more clearly visible. If there is pink porcelain, the transition between it and the real gum may look different as the gum takes shape; this transition is monitored at the check-ups in the clinic's follow-up plan.

3. Over the years: ceramic

   Laboratory data show that translucent zirconia keeps its colour up to a certain ageing duration and can change with longer ageing. These data cannot be translated directly into years in the mouth; keeping the surface polished and intact helps preserve the colour.

4. Over the years: acrylic

   In the laboratory, conventional acrylic teeth soaked in coffee showed a visibly noticeable colour change after 30 days; milled acrylic stayed more stable. This period cannot be translated one-to-one into time in the mouth; even so, acrylic surfaces pick up colour from coffee, tea and smoking more easily than ceramic.

5. Over the years: natural teeth

   Natural teeth remaining in the mouth continue to darken and turn more yellow with age. The difference from ceramic fixed teeth can grow over time; choosing an in-between shade with this in mind is one option.

You will not find figures here. Although choosing the colour is not a separate item in itself, how the colour is produced changes the scope:

Single colour or layered colour

Teeth made from a single block and teeth whose biting edge and neck are coloured separately require different laboratory work.

Pink porcelain

Gum-coloured ceramic is coloured and designed separately; whether it is needed depends on bone and gum loss and on the smile line.

Material

Acrylic, zirconia and porcelain-veneered structures differ both in colour stability and in how they are made. A detailed comparison is in the materials guide.

Remaining natural teeth

If the natural teeth need whitening or renewing for harmony, this also becomes part of the scope.