The power of Color: Blurred Lines

Shadeguides - Tips and tricks - Direct anteriors
17 Mar 2016

Teeth are tremendously important features in our face. They define a person more than one might realise.

When a patient in need of treatment presents itself with a unique eye-catching characterization in their front teeth, we are challenged by nature. Trying to exactly recreate those eccentricities requires a very good examination before starting the treatment. Digital photography (with filters as a valuable addition) is an excellent help to define the tooth structure appearance in mind. It will help to see those small details, especially in those dynamic incisal third areas, so your hands can create them. Patients do not always want to keep those special features when their front teeth are restored. Often is asked to remove all the discoloured enamel. If somebody does want to keep the characterization, as a dentist there is the challenge to attempt to replicate that exact natural layering in the restoration. In this case small white opaque spots and striations can be seen all over the dentition. Fortunately this young patient wanted to keep the natural beauty of her teeth which was not present anymore in the restoration previously made. The patient had suffered a fracture of tooth #11 several years ago.

Fig. 1

Fig.1- Frontal view retracted: monocoloured restoration on central right maxillary incisor can be noted. The patient had approximately one month earlier finished the orthodontic treatment. She wanted a more natural looking restoration as her natural dention was full of colour and opacity differentiation.

Fig. 2

Fig. 2- Left lateral retracted view. The surface structure of the restoration in situ did not match with the left central incisor. Also was taken note that the angulation of the incisal third, bending slightly towards the palatal on tooth #21, was absent.

Fig. 3

Fig.3- Right lateral view. Apparently a diastema of 1mm in between tooth #12 en tooth #11 had developed in that period.

Fig. 4

Fig.4- In both maxilla and mandibula throughout the whole dentition white spots and striations can be noted. Especially in the incisal third area.

Fig. 5

Fig.5- A fixed retainer was in place at the first consultation. The bar was removed in order close the diastema by wearing a clear overlay retainer. Removal of the wire also created an ideal restoration site for both good possibility to place the rubberdam and proper acces during treatment.

Fig. 6

Fig.6- After taking preoperative photographs impressions were made in order to make a wax-up of tooth #11. The wax-up shows proper form and shape with the desired slightly palatal angulation of the incisal third and small nodges in the incisal edge. If doing a multilayered restoration the exact right placement of the different colour, opaque and translucent composites is of the greatest importance. The wax-up serves to make a silicone index to transfer the result intraorally during the stratification treatment ensuring a more spot on layering in the sagittal and vertical plane.

Fig. 7

Fig.7-A close-up was altered by raising contrast and lowering the brightness. This puts the emphasis on the internal colour build-up of the tooth making it easier to read. The first colour selection was made.

Fig. 8

Fig.8- The preliminary selection was put on the neighbouring tooth #21 and light cured. If the rubberdam is in place you have to do this prepared within minutes because of very rapidly dehydration of the tooth occurs resulting in loss of true colour character. Tooth structure becomes more opaque because of the blocked passage of light. The colour analysis has to be trusted throughout the whole further treatment. An A2 dentin and body composite was chosen, a white enamel, a clear translucent enamel and amber enamel.

Fig. 9

Fig.9- The rubberdam isolation in perfectly place because of the absence of the fixed retainer .

Fig. 10

Fig.10- The silicone index checked intra-orally for perfect seating and absence of rubberdam interference before starting treatment.

Fig. 11

Fig.11-Close-up of the silicon index shows the mesial and incisal edge will look different after treatment. The index ensures the edge does not need to be altered afterwards keeping the dynamic incisal third colour pattern intact.

Fig. 12

Fig.12- Ater removal of the old composite restoration, all sharp edges were rounded up and a 2-2,5mm bevel was placed.

Fig. 13

Fig.13- After 35% phosphoric acid etching for the enamel for max. 30 seconds and the dentin for 15 seconds, rinsing, applying primer and bonding and lightcuring, the silicon index was checked again for accurate seating.

Fig. 14

Fig.14- With the LM-Arte instrument Fissura the transition line was marked in the putty. Any caused debris was blown away before applying composite in the shell. The transition line prevents overapplying composite reducing the finishing time on the palatal later.

Fig. 15

Fig 15-After placing a white enamel composite in the matrix, the matrix was seated and by instrument and brush shape and perfect adaptation to the bonded tooth structure was assured. On the palatal no bevel was made to avoid possible air voids.

Fig. 16

Fig. 16- Extra light curing on the palatal after light curing from the buccal first before removing the putty.

Fig. 17

Fig.-In both mesial and distal corner application of white colour effect using LM-Arte Fissura instrument. A rounded very small brush can also be used in a tapping motion to distribute and absorb a possible overdose.

Fig. 18

Fig.18-Mamelon base was created using the dentin composite.

Fig. 19

Fig.19- An A2 body composite was placed in mamelon shape over those already formed in dentin composite in order to make the dentin less prominent in the final result
Striations were made with a #06 endofile before light curing the composite.

Fig. 20

Compared: White effect colour mixed with sculpting/composite instrument wetting resin on the left and on the right the original white effect. Note the intensity of the color level dropping down creating a distinct difference. Opening up an larger array of indication of use for the white colour effect. The use of bonding should be avoided because of the presence of the hydrophilic monomer HEMA in most adhesives.

Fig. 21

Fig.21- Applying the altered, moderated colour effect to create the striations. Diffuse slightly by brush before lightcuring.

Fig. 22

Fig.22- Clear translucent enamel composite is packed in between the mamelons with a dash of amber composite on the mid incisal edge. Using a spatula instrument to check the already defined incisal egde shape not being surpassed before polymerisation. Finally the last layer of white enamel was placed.

Fig. 23

Fig. 23- After application of the last layer of enamel composite further adjustments were made according to the last article The Power of Pencil.

Fig. 24

Fig.24-Surface structure of the neighbouring central incisor was identified by carbon paper and copied using a diamond bur at very low speed without water.

Fig. 25

Fig.25- A white stone was moved manually in a horizontal way to create the illusion of perykimata.

Fig. 26

Fig.26- Carefully accentuating the little incisal notches.

Fig. 27

Fig.27- Polishing was started after creating the surface structure and consisted of multiple steps to achieve a low surface roughness. Only when polished the effects put in the restoration can fully come to life. This will give the restoration shine and luster and the smoothness of the composite will help prevent future unwanted staining.
The multistep polishing procedure starts with the beige Sof-Lex spiral elastomer wheel.

Fig. 28

Fig.28- Followed by the white one.

Fig. 29

Fig. 29-Last step is to use an aluminiumoxide paste together with a felt coated disc for final gloss.

Fig. 30

Fig.30- Directly after rubberdam isolation removal.