TECHNIQUES FOR VARIOUS PROBLEMS

Table 8–2. Guide for Staining to Add Characterization

The most commonly encountered problems that can be corrected through illusions are discussed below.

Space Available is Wider than the Ideal Replacement Tooth

This problem is typically encountered either when space was present between the teeth prior to extrac-tion or when drifting has occurred to widen the space. If the space is to be restored with the correct number of teeth and tooth contact is to be re-estab-lished, avoid horizontal lines, edges, and character-izations, and incorporate as many vertical ones as possible into the restoration.

Shaping

The width of the replacement tooth or teeth will have to be wider than ideal; therefore, various illu-sions achieved through shaping and contouring should be used. The width needed to close the space is gained in the areas of contact.

Illusions for Incisors

The extra width can be disguised by placing the contact areas more lingually and cervically. In Fig-ure 8–11, the diameter of tooth “a” is larger than that of tooth “b,” but by carving the mesial and dis-tal line angles to the lingual, the tooth appears thinner. One reason for this illusion is the reflec-tion created by shaping and contouring the tooth.

Light usually reflects from the flat labial surface.

Line angles “e” and “f ” usually reflect light and give the appearance of width to the tooth. The corre-sponding lines on the right central would be “g”

and “h.” By moving the mesial and distal line angles slightly to the middle of the tooth, new line angles “c” and “d” are created and thus less flat labi-al surface remains. This reduction in the reflective surface makes the tooth appear narrower than it really is. Although these should be subtle carvings, at times, labial prominences can be created to actu-ally catch light rays. In this manner, more precise distance can be interpreted by the observer.

Summary. The mesial and distal line angles in Figure 8–11 are moved toward the center of the labial surface (c and d). The mesial and distal sur-faces are then made more convex, curving from the line angles into the areas of contact.

The shape of the incisal edge can abet the illu-sion of decreased width. The mesioincisal corner is rounded, and a gentle curve is created from the middle third of the incisal edge to the distal contact (Figure 8–12).

The incisal edge can be notched slightly to break up the horizontal line. Even a slightly curved indentation, a wave result, will alter visual percep-tion and create a more pleasing effect. The eye tends to wander away from a horizontal line, and the curves provide relief.

Only a limited amount of mesioincisal rounding permitted, mainly due to the possibility of creating asymmetry in the restoration by overdoing it. It is possible, however, to create the illusion of a slight incisal diastema by moving the mesial contact of the larger tooth gingivally. This produces an entire-ly different effect than a complete diastema. The open incisal diastema can be natural in appearance and quite effective in balancing space variations.

More incisal shaping is possible from the distal side. Since the observer sees the patient mainly from straight ahead, it is possible to achieve much of the space illusion by opening the distoincisal embrasure. The distance (Figure 8–12) c–d is also re-emphasized by carving mainly from this point, both mesially and distally.

At times, it may even appear as if a diastema is placed distally, depending on how much the con-tact is placed gingivally. This is still a much better esthetic choice than having an oversized contra-lateral central incisor.

Illusions for Cuspids

Extra width can be disguised by moving the visual center of the labial or buccal surface more to the mesial by carving the buccal ridge to the mesial (Figure 8–13). The cusp tip should then be moved mesially if this is compatible with functional requirements. Contact areas should also be moved lingually and cervically.

Illusions for Anterior or Posterior Teeth The developmental grooves are moved closer together (Figure 8–14). These grooves do not have to be deep to be effective. Shallow grooves will give the desired shadows. To further this illusion, any

Figure 8–12: Gentle curving of the mesioincisal and disto-incisal edges, as well as a slight indentation at the middisto-incisal edge, alters visual perception.

Figure 8–13: A, This figure illustrates a too-wide cuspid. B, The buccal ridge is carved to the mesial to disguise the excess width in the cuspid.

Figure 8–11: Tooth a is made to appear thinner than it actu-ally is by carving the mesial and distal line angles to the lin-gual, thus presenting less labial surface.

a b a b

c d e f

c d

g h

characterizations ground into the labial or buccal surface should be vertically oriented. By breaking up the smooth unbroken labial or buccal reflecting surface with characterizations, you make the tooth appear less wide.

The curve of the cementoenamel junction carved into the restoration can be made more pro-nounced and brought into a more incisal or occlusal position in the interproximal gingival embrasure areas (Figure 8–15). When shaping the restoration, the opposite tooth should be kept in mind as the ideal.

Slight concavities in the gingival third also give the illusion of a narrower tooth. Special attention should be paid to duplicating ridges and depres-sions that reflect light (Figure 8–15). One should remember that it is the individual pattern of light and color reflection that determines tooth charac-ter. Figure 8–16 shows all the shaping effects com-bined to produce the illusion of a thinner tooth.

Staining

For masking a large tooth, color can be used to advantage in one of several ways.

Figure 8–14: Shallow developmental grooves which break up the smooth labial reflecting surface make the tooth appear less wide.

Figure 8–15: A more pronounced curve carved into the cementoenamel junction which is in a more incisal or occlusal position is another technique used to make the tooth appear thinner.

Figure 8–16: All three shaping special effects are combined on this restoration to produce the illusion of a thinner tooth.

b a

By selecting a body color barely darker than that of the approximating teeth, the larger tooth appears less prominent. The mesial and distal thirds of the labial or buccal surface can be stained grayer (Fig-ures 8–17A and B) than the middle third. The gray color disappears in the mouth and the appearance of size is transmitted to the glancing eye by the nor-mally colored area. Note how much thinner the teeth appear in Figure 8–17B after using the above technique. The developmental grooves and charac-terizations ground into the surface can also be emphasized with gray stain. Indefinite, barely per-ceptible, vertical lines can be incorporated to accent the vertical aspects of the tooth. This is done by using a stain slightly lighter than the body color and by running it from the tooth body to the incisal or occlusal edge. To further highlight the lighter lines suggested above, an opaque white, yellow, orange, or brown stain can be used to create vertical check or microcrack lines (see Figure 8–10C).

Arrangement

The position or arrangement of the teeth can create the illusion of decreased width. When a tooth is placed in linguoversion, not only is its real width masked by the more prominent approximat-ing teeth but the effect of the increased shadowapproximat-ing also masks its size (Figure 8–18). Rotation of a tooth from its normal labiolingual position will accomplish several illusions. Through rotation, the normal perception of the tooth is changed, and the tooth loses some of its identity. Depending upon the degree of rotation, the tooth can be made to appear less wide. In Figure 8–19A, the right central

appears wider than the left central; actually the left central is rotated distally, so it looks thinner (Figure 8–19B). When the mouth is viewed from midway between the rotated and nonrotated teeth, the teeth look much the same width (Figure 8–19C). When two central incisors are replaced, the distal aspects of the wide crowns are rotated lingually, thereby narrowing the area that reflects light forward and decreasing the apparent width (Figure 8–20). You can create a diastema to avoid widening the replacement teeth. Position the teeth so that the space left on the distal aspect of the restoration is not prominent (Figure 8–21).

If the space to be filled is much wider than the replacement teeth, the only reasonably esthetic solu-tion may ultimately be the addisolu-tion of an extra tooth. This method of handling the extra space works especially well when replacing the lower ante-riors. (You may refer to Esthetics in Dentistry Vol.

II, Chapter 24: Restorative Treatment of Diastema.) Space Available is Narrower than the Ideal Replacement Tooth

This problem is usually encountered when extrac-tion was not immediately followed by replacement and the adjacent teeth drifted or tilted to encroach upon the space. If the space is to be restored with the correct number of narrower teeth, avoid verti-cal lines, edges, and characteristics, and incorporate as many horizontal lines as possible.

Shaping

Before the replacement crowns are shaped, the proximal surfaces of the adjacent teeth should be

Figure 8–17A: These two central incisors appear too wide with respect to the other teeth in the patient’s dentition.

Figure 8–17B: The mesial and distal thirds of the labial sur-face are contoured and stained a darker gray to give the appearance of thinner teeth. In addition, the incisal was slightly curved to break up the “straight across” and wider appearing line angle.

reduced slightly to increase as much as possible the space available. Most or all of the needed space can be obtained in this fashion. If this procedure is used, the reduced enamel surfaces must then be refinished

(see Chapter 11). By altering the contour of the labi-al or bucclabi-al surface and the incislabi-al or occluslabi-al edge, an illusion of width can be achieved, even when the actual tooth is narrowed.

Figure 8–19A and B: Although the right central appears wider than the left central, the left central is actually rotated distally which causes it to look thinner.

Figure 8–19C: When the patient is viewed from a different angle (halfway between the rotated and nonrotated teeth) the teeth look proportional.

A B

Figure 8–18: Placing the wider tooth in linguoversion masks its real width by diminishing its prominence with the adja-cent teeth and adding shadowing.

b a

X Y

Figure 8–21: When a space is too wide, a diastema is prefer-able to making the replacement tooth too wide.

plished by carving the buccal ridge to the distal. The cusp tip should be moved distally if this is compat-ible with functional requirements, and the contact areas should be moved labially and incisally to accent the horizontal aspects of the narrow tooth.

Illusions for Anterior or Posterior Teeth The curve of the cementoenamel junction can be influential. It should be at the same level as the curve on the adjacent natural teeth but should have a flatter appearance (Figure 8–24A). To further accentuate the horizontal, additional grooves can be carved gingivally on the original one (see Figure 8–24A). However, if the adjacent natural teeth have strong vertical lines, this cannot be done effec-tively; therefore, the effort should be directed toward de-emphasizing as much as possible any vertical lines or edges. If there are only a few verti-cal lines on the adjacent natural tooth, it may be possible to cosmetically contour the labial surface on that tooth to diminish their effect.

Illusion for Incisors

The contact areas are moved labially and incisal-ly, as illustrated in Figure 8–22. In this case, the right central is narrower than the left central and needs to be made to appear wider. By extending the contact areas both labially and incisally, the appar-ent width of line angle X is increased and helps make the right central look wider than it really is.

If the previous technique is used in conjunction with flattening the entire labial surface and the prox-imal line angles, the overall effect will be lengthening of the incisal edge and development of a broad labi-al surface for light reflection. Both of these effects heighten the illusion of width (see Figure 8–22).

Another technique is to leave the incisal edge as flat and as horizontal as is compatible with adjacent teeth (see Figure 8–22). It may also help to reshape the incisal edge of the adjacent teeth slightly to help make the entire effect more esthetically harmonious.

The adjacent central incisor can be shaped to look narrower by carving its distoincisal edge gingivally.

Illusions for Cuspids

The narrowness of the crown can be disguised by moving the visual center of the labial or buccal sur-face (Figure 8–23) more distally. This is

accom-Figure 8–20: The distal aspects of both the replaced central incisors are rotated which narrows the light reflecting surface and decreases width perception.

By eliminating developmental grooves and lobes, the labial surface can be carved to develop a broad, flat surface to provide an area for unbroken light reflection. This area will appear broader than the same area that has the surface broken with grooves and characterizations that scatter the reflec-tions (see Figure 8–24A).

Staining

Color can also be used to increase the illusion of width. For instance, when a body color is selected that is slightly lighter than that of the adjacent teeth, the narrow tooth will appear more promi-nent and therefore wider. The mesial and distal thirds can be stained a shade lighter than the mid-dle third, to highlight the proximal aspects and the width of the tooth. Any horizontal grooves or lines that have been carved into the labial surface can be accentuated with a light stain. Definite, barely per-ceptible, horizontal lines can be created to accentu-ate width. This is done by choosing a stain slightly lighter than body color and running it from mesial

to distal. To further accentuate these lines, a light, thin orange, yellow, brown, or white opaque line can be placed on the labial surface (Figure 8–24B).

Another way to accentuate width is to simulate multiple decalcification spots running horizontally across the middle third of the tooth (Figure 8–24C).

Other horizontal lines can be created by using staining to indicate one or two anterior restorations that have been carried out onto the labial surface.

If adjacent teeth show cervical erosion, this erosion should either be restored or reproduced in the replacement tooth. Staining can be used to create an illusion of erosion, and if it is horizontal and flat, it will emphasize width (Figure 8–24D).

Arrangement

The most simple and direct solution for inade-quate space is to rotate and overlap the replacement crowns or teeth without reducing their ideal widths. If rotation and overlapping is unacceptable or impossible, and if the encroachment upon the space has been severe, it may be possible to elimi-nate one tooth entirely with good results, especial-ly in cases involving lower anteriors. In cases where the maxillary central incisors are involved, the dis-tal aspects can be rotated labially, making these teeth appear more prominent and wider (Figure

Figure 8–22: The narrow right central incisor needs to appear as wide as the left central incisor. The line angle X is extended labially and incisally, making the right central appear wider. If necessary, the distoincisal angle of the wide incisor can be reshaped, making it appear slightly narrower.

Figure 8–23: When the crown of the cuspid is too narrow, move the visual center of the labial surface distally by carving the buccal ridge distal to the usual position if this remains compatible with functional requirements.

X Y

a b

8–25). The principle involved here is to create prominent distolabial line angles to create more horizontal reflections.

When the problem involves both maxillary cen-tral and lateral incisors, the cencen-trals can be placed normally and the laterals can be rotated. In the case of a male, the mesial aspects of the laterals are rotat-ed and lapprotat-ed lingually behind the centrals increas-ing the overall appearance of width and boldness

and decreasing the amount of space needed (Figure 8–26A). In the case of a female, the mesial aspects of the laterals are rotated labially and lapped in front of the centrals, increasing the feminine appearance (Figure 8–26B).

The Too-Short Tooth

If a tooth appears too short, as is likely if it is wider than normal, several techniques can be used to cre-ate the illusion of length.

Figure 8–24A: Horizontal grooves were carved into the right central (1) to give it a wider appearance.

Figure 8–24B: Light, thin, orange and yellow opaque lines were placed on the surface to further enhance the carved horizontal lines.

Figure 8–24C: White calcification spots running horizontally across the middle third of the tooth further accentuate width.

Figure 8–24D: Staining used to create the illusion of cervical erosion to match adjacent teeth also emphasizes width if the crown is horizontal and flat.

B C D

X Y

1 2

Figure 8–25: For an inadequate space involving cen-tral incisors, the teeth can be slightly rotated labially and lapped rather than reducing their ideal width, making them appear wider and more prominent.

Figure 8–26: A, The mesial aspect of the lateral incisor of this male patient is rotated and lapped lingually behind the central to project width and boldness without requiring addi-tional space. B, For a female, the mesial aspect of the lateral incisor is rotated labially and lapped in front of the centrals to increase a soft, feminine appearance without increasing the space needed for the replacement teeth.

Shaping

If the gingival third is narrowed mesiodistally (Fig-ures 8–27A to C), the tooth will appear more tapered and longer (a). This illusion can be further enhanced by having a vertically flat labial middle third to increase the vertical reflecting surface (b,c).

The shape of the incisal edge can be altered to cre-ate an illusion of grecre-ater length in the anterior region.

For each involved tooth, the mesial and distal halves can be sloped gently toward the gingiva from the midline to the contacts (Figure 8–28A). In the spe-cific case of the central incisors, each incisal edge can be made to slope gingivally away from the approximating common incisal angles, lending the illusion of length (Figure 8–28B).

Staining

The main principle to remember when using staining to increase height is that stains of higher value (whiter) make the area to which they are applied more noticeable. A fine, opaque, white check-line running from the body of the tooth to the incisal edge accentuates the height. A white decalcification spot placed close to the incisal edge also increases the height illusion. Staining can be

used to duplicate the appearance of a long, vertical interproximal anterior restoration, which increases the illusion of length (Figure 8–29A).

Arrangement

If the maxillary six anterior teeth have worn unnaturally, producing noticeably shorter teeth, consider cosmetic contouring, to create the illusion of longer teeth, by shortening the laterals slightly

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