Overcoming the Impossible: A Porcelain Laminate Technique
By Irwin Smigel, DDS
Rick (Figs. 1, 3) came to my office unhappy with his appearance. He had visited several dentists and had been told that correcting his situation would require orthodontic therapy for two years and then a retainer for an indefinite period. Not particularly excited about this prospect, he was determined to seek an alternative treatment.
There did not appear to be an alternative at first blush. His maxillary right lateral incisor (Fig. 5) not only overlapped the right central, it protruded labially approidmately 45 degrees from the other anterior teeth (Fig 8). Even my associates, who had overcome many aesthetic problems with me, were pessimistic.
"Perhaps we should widen his arch and bring the lateral into alignment orthodontically," one suggested. "It might also straighten his irregular gingival alignment (Fig. 11)."
That was a viable option, but it was not the solution for which Rick had come to our office. He was searching for a quick fix. If his aspirations had been out of line, he certainly would have been rebuffed forth with. The longer his situation was examined,. however, the more interesting the possibilities became.
As difficult as Rick’s case appeared to be, he had presented with three important assets: His right lateral (Figs. 5, 8, 11) had undergone considerable treatment. Most notable was the large Class III mesial composite. There also two smaller restorations, however - facially and distally. Consequently, while the tooth pulp tested normally. the pulp chamber had receded significantly, which allowed considerably more leeway during preparation.
Second, both central incisors were in substantial lingual version, the right more so than the left. I visualized building both centrals facially, to a degree where they could be close to alignment with the right lateral. Since the right lateral could be amply reduced, It was determined to resolve the case with porcelain laminates.
The third advantage was Rick's lipline. Smiling as wide and strongly as he could (Figs. 1. 3), he did not expose the irregular, receded gingival area above his right lateral. This eased the task considerably. Surgical intervention glingivally would have been superfluous. Aligning his anterior teeth would achieve the desired aesthetic result.
Proper preparation was essential. Every tooth had to be reduced in harmony with the final desired effect. Dr. Bijan Gohari, who prepares and impressions teeth for laminates in our office, carefully examined Rick's X-rays and study models before preparing the central and lateral incisors.
The right lateral (Figs. 6, 9, 12) was shortened extensively, as well as being facially and incisally reduced. The incisal reduction permitted a lingual lean of the incisal half of the completed lateral laminate (Figs. 7, 10, 15). The mesial reduction eliminated the lateral overlap on the distal gingival of the right central (Fig. 6), and the facial reduction enabled the laminate to be brought lingually into an even alignment.
Since the right lateral was to be extremely thin, it was imperative that the underlying tooth be of a uniform color. Dr. Gohari replaced the mesial composite with shade A3.5 TPH (Caulk) using the new 3M multi-purpose as the adhesive (Fig. 6).
It is apparent that Rick's midline is not centered (Fig. 3). This is further emphasized by the rightward tilt of the tip of his nose. While impossible to straighten completely, the combination of premeditated preparation and the use of illusions can often do wonders. Both centrals and the left lateral were shortened incisally; not as much as the right lateral, but again done to control the incisal lean. The mesial of the right central and the distal of the left central were reduced as much as possible (Fig. 12) to move the midline to the right. This could not be done solely by reduction. The 3mm discrepancy could not be transferred safely to the teeth.
Illusions were used as well. The distal ledge on the right central and the mesial ledge on the left central were emphasized to delude the eye into seeing a rightward slant. This combination of tooth reduction and illusion yielded a more centralized smile (Figs. 4, 15).
The feminine effect in his smile was emphasized by small laterals with curved incisal edges. The illusion was changed by making the centrals and laterals wider and sturdier, the laterals longer, and providing all four incisors with straight incisal edges (Fig. 15).
The final result (Figs. 2. 4, 7. 10, 15) could not have been achieved by simply writing a prescription to a technician, particularly without his or her seeing the laminates in the mouth. I gave my technician (Adrian Jurim of McAndrews Northern Laboratory) detailed instructions as to what was intended with this case and had him overbuild the teeth in line with those instructions. Then Shofu chipless stones were used to painstakingly refine each tooth until I had the effect I wanted. The laminates were smoothed with a rubber wheel and finally reglazed (in my hands) with a diamond polisher, Diaglaze (Antraco).
The last problem was color. Two of the laminates, the right lateral and central, were considerably different in thickness. The lateral was approximately 0.3mm thick, while the thickness of the central was 0.7mm, more than double the lateral bulk. Too thick a porcelain makes it difficult to attain the naturalness and inherent translucency so characteristic of porcelain laminates. It took considerable trial and error, but the technician finally overcame this by filtering incisal translucence into the right central nate.
I have used Ultrabond (DenMat) to bond laminates for the past 15 years, occasionally adding opaque modifiers (Kerr) to further enhance the color. The bonding material in Rick's situation could influence the shade of both laterals and the left central. The thickness of the right central, however, precluded any possibility of the shade being affected.
Consequently the right central was inserted first (Fig. 13) while the other laminates, whose shades could be influenced, were bonded in afterward. The left central and lateral presented no problem. Shade 59 Ultrabond matched them exactly to the right central. The right lateral was more of a problem. It required a combination of 59 (Ultrabond) and a touch of white and gray opaque to finally blend with the other laminates (Figs. 7, 10, 15).
The case was not yet complete. Moving the teeth to the right had accentuated the space between the left lateral and canine (Fig. 14). I closed the space by bonding the left canine with TPH (Caulk), employing the combination of shades A2 and A3.5 to make it harmonious with its right counterpart (Fig. 15).
Rick had suffered all his life because of the irregularity of his anterior teeth and the extreme labial protrusion of his right lateral. Orthodontics would have been the treatment of choice at an early age, but for the stage at which I met him, it would have been time consuming with a distinct possibility of regression.
Certainly not every case of this magnitude can be resolved with laminates, but the purpose of this article is to demonstrate what is possible when we take advantage of some of the advances that have so benefited our profession.