Restoration of Maxillary Anterior Teeth Using Porcelain Jacket Crowns and Porcelain Veneers Steven T. Cutbirth, D.D.S."
Combining different types of restorations when restoring maxillary anterior teeth poses a difficult esthetic problem. This article describes a method of restoring maxillary anterior teeth using a combination of porcelain jacket crowns and indirect porcelain laminate veneers.
ndirect porcelain laminate veneers are often indicated when bleaching techniques or direct composite bonding procedures cannot provide the desired esthetic result. Indirect veneers are more appealing to many patients than full coverage crowns mainly because of the more conservative tooth preparation required. If meticulous attention to technique details are followed and cases are appropriately selected, indirect porcelain veneers are not only durable but also promote excellent gingival health and may well be the most esthetic anterior dental restoration. When the restoration of maxillary anterior teeth requires indirect porcelain veneers in combination with full coverage crowns, the indirect porcelain veneers should be completed prior to fabricating the full coverage crowns. This sequence is followed because an excellent porcelain technician can match the subtle hue, chroma, and value characteristics of the indirect porcelain veneers in his full coverage porcelain jacket crowns more exactlythan the dentist and the technician can match the porcelain jacket crowns with indirect porcelain veneers. In the following case presentation, twin foil porcelain jacket crowns were used to restore the maxillary central incisors. Indirect porcelain veneers were placed on the maxillary right and left lateral incisors and canines.
TECHNIQUE A middle-aged woman was concerned about the appearance of her maxillary anterior teeth. Her central incisors had been restored previously with porcelain fused to metal crowns that were overly opaque, did not match the hue, chroma, or value of the adjacent teeth,
*hivate Practice, Waco. Texas Address reprint requests to Steven Cutbirth.D.D.S.. 1613 Lake Success, Waco. TX 76710 0 1992 Decker Periodicals Inc.
B Figure 1 A and B, Preoperative appearance of patient.
and exhibited metal margins (Figs. 1A and 1B).The maxillary canines and lateral incisors had darkened with age. The existing crowns on the premolars and molars were also replaced as part of this case, but that particular technique will not be discussed in this article.
aspects of the teeth to be laminated to the predetermined ideal dimension. This step may be regarded not as tooth preparation, but tooth reshaping, and it is based on both preclinical analysis of study models mounted on a semi-adjustable articulator in centric relation, and excellent photographs or slides of the anterior teeth. The objective is to achieve the best possible arch form and incisal edge positions prior to laminate veneer tooth preparation. The same round-ended diamond was then used for preparation of the lateral incisors and cuspids for indirect porcelain laminates. The facial surfaces and the incisal edges of the laterals and canines were reduced approximately 0.5 mm. The incisal finish line should be located on the lingual surface so that the laminate covers the entire incisal edge. The incisal preparation should taper gingivally from the lingual to the facial. The interproximal margins should be located just labially to the proximal contact areas, taking care to extend the proximal preparations lingually in the gingival one third of the teeth so that margins are not evident facially. A deep chamfer margin was placed gingivally and interproximally. The preparation was completed using a Brasseler 8878-016 or 014 fine chamfer diamond to finish all margins. Retraction cord is seldom necessary. The tip of the 8878 chamfer diamond was extended approximately 0.5 mm into the gingival crevice and any “lipped enamel that may have been left after preparation was removed with the 6856 round-ended diamond. A knifeedge margin should be carefully avoided. The margin should be a deep chamfer.The remaining margins of the preparations were polished with the 8878 chamfer diamond to smooth any rough edges. The completed preparations on the lateral incisors and canines are shown in Figures 3A and 3B. Since provisional veneers are seldom placed, every effort should be made to seat the laminates as soon as possible. The patient should be advised that some sensitivity may occur until the final restorations are
Figure 2 Porcelain jacket crown preparation and retraction cord placement.
Porcelain Jacket Crown Preparation After the existing porcelain fused to metal crowns was removed from the maxillary central incisors, the teeth were prepared using a Brasseler 6856-0 18roundended coarse diamond (Savannah, GA) and a Brasseler end-cutting diamond for porcelain butt margin preparation (Fig.2). Van R size 1 gingicord was placed on the facial aspect of the teeth prior to extending the facial butt margin 0.5 mm subgingivally. Provisional crowns were fabricated indirectly using Cold Pak cold cure acrylic. The maxillary central incisors were not impressed for porcelain jacket crown fabrication until after the indirect porcelain laminates had been seated on the maxillary lateral incisors and canines.
Indirect Porcelain Veneer Tooth Preparation A Brasseler 6856-0 18 or 0 16 round-ended coarse diamond was used to contour the labial and incisal
B Figure 3 A and 8,Completed preparations for indirect porcelain veneers.
Restoration of Maxillary Anterior Teeth
cleaned with cotton balls soaked in hydrogen peroxide. A thorough rinse followed. The lingual surfaces of the porcelain veneers were etched with hydrofluoric acid by the laboratory technician prior to delivery (Figs. 5A and 5B). A 2x2 cotton gauze square was placed behind the patient’s teeth as a safety net. The porcelain veneers were dipped in water and seated on the teeth. The water allows the veneers to stick to the teeth. The margins of the laminates should fit the prepared teeth precisely. The laminates were removed, rinsed with distilled water, and dried. The enamel/dentin surfaces were etched with 10% phosphoric acid (AllEtch, Bisco Inc.) for 15 seconds, rinsed, and dried. Silane porcelain primer was applied to the etched surfaces of the veneers. The Bisco Choice Porcelain Veneer system was used to bond the indirect porcelain veneers. Three to five coats of mixed primer (Bisco Primer A and B) were applied to the dry, prepared surfaces of teeth, followed by gentle warm air blowing. The tooth surface should appear highly glossy followingprimer application. When bonding indirect porcelain veneers to teeth, it is not necessary to apply dentin/enamel bonding resin. Only several coats of mixed Primer A and B are required. A thin matrix strip (shim stock - 0.0005 inch thick) was placed interproximally between all teeth to be laminated. The use of a wedge should be avoided. The appropriate shade of porcelain adhesive paste was selected and a thin layer was applied to the lingual surface of the porcelain veneer seated first. The incisal portion of the veneer was seated first, then gentle pressure was applied on the laminate in a gingival/lingual direction until the laminate was completely seated (Fig. 6).Excess composite should extrude from all margins. Excess composite should not be removed until after light curing. Otherwise marginal voids may occur. Each laminate was immediately cured
4 Patient as she left the office after preparation of maxillary central incisors for porcelain jacket crowns and maxillary cuspids and lateral incisors for indirect porcelain laminate veneers.
placed. The patient should wipe the teeth twice a day with a cotton ball soaked in hydrogen peroxide mixed with lukewarm water, and should continue to floss daily. Incidentally, sensitivity may be entirely eliminated by the application of five coats of Allbond Primer (Bisco Inc., Itasca, IL) to the preparations. It is essential that the gingival tissue is healthy and does not bleed or “weep”when the porcelainveneers are seated. This allows an environment for ideal bonding. The veneer-prepared anterior dentition, together with temporary crowns on the central incisor, are shown in Figure 4.
indirect Porcelain Laminate Veneer Insertion After the administration of local anesthetic, the teeth were gently flossed with unwaxed dental floss dipped in hydrogen peroxide. The prepared teeth were
A Figure 5 A and B,Indirect porcelain laminate veneers as received from the laboratory technician.
JOURNAL OF ESTHETIC DENTISTRY VOLUME 4, NUMBER 1, January/February 1992
tooth), and 30 seconds on the incisal surface of each tooth. This may be considered overcuring, but remember that the primary cause of bonding failure is undercuring. Overcuring is never a problem. The excess marginal composite was removed with thin 12 and 30 fluted carbide finishing burs (Fig. 7A). The interproximal areas were polished with finishing strips (Fig. 7B).The interproximalareas were checked using unwaxed dental floss. Centric occlusion and all eccentric movements were carefully checked. The interproximal and incisal areas were polished with porcelain paste applied with a rubber prophylaxis cup. A gentle approach must be used when polishing the gingival margins, as the diamond paste may be irritating to the gingival tissue. Figure 8 shows the bonded veneers on the maxillary cuspids and lateral incisors together with the provisional crowns on the maxillary central incisors.
Porcelain Jacket Crown Fabrication and Insertion Hue, chroma, and value selection for the porcelain jackets is critical. This shade selection procedure is best done by a combination of (a)high-quality photographs of shade tabs held adjacent to the inserted indirect porcelain laminate veneers and 03)a customized shade taken by the technician with the dentist. It allows the technician to see hue, chroma, value, contour, and texture of the laminate veneers first hand and, also, to compare the shade of the veneers to the shade tabs photographed. With this first-hand information, he can then use the photographs of the laminates with shade tabs most effectively. The central incisors were repacked on the facial aspect with size 1 Van R gingicord. Impressions were taken of the inserted indirect porcelain laminate veneers on the lateral incisors and canines along with the
Figure 6 Seating of the indirect porcelain laminate veneers in a gingival lingual direction.
for 20-30 seconds while pressure was applied in a gingivolingualdirection with a cotton-tipped applicator. This process was repeated with all laminates. Once all laminates were seated with porcelain adhesive paste, they were light cured for 60 seconds on the facial surface, 60 seconds on the lingual surface (through the
Pigure 7 A, Removing excess marginal compositefrom indirect porcelain laminate veneers. B, Completed indirect porcelain laminate veneers on the upper cuspids and lateral incisors.
Restoration of Maxillary Anterior Teeth
A Figure 8 Provisional acrylic crowns have been placed on the upper central incisors after preparation and impression for porcelain jacket crowns.
B Figure 10 A and B,Postoperative photographs of the patient. Porcelainjacket crowns have been placed on the central incisors
Figure 9 Try-inofporcelainjacket crowns on the upper central incisors.
and indirect porcelain laminate veneers have been placed on the
maxillary cuspids and lateral incisors. Note the contrast between the preoperative appearance of the dentition (Figs. 1A and 1B) and the postoperative appearance (Figures 1OA and 1OB).
If the patient is a bruxer, a night guard should be fabricated to protect the anterior restorations and the opposing teeth.
central incisors that had been prepared for porcelain jacket crowns. The twin foil was removed from the porcelain jacket crowns and the jackets were placed on the prepared teeth to conAnn marginal fit, contour, texture and ideal hue, chroma and value (Fig. 9). The jackets were cemented into place with KetacCem glass-ionomer cement, and the occlusion was adjusted (Figs. 10A and 10B). In this particular case, the lower teeth were bleached utilizing a bleaching stint and "at home" bleaching method.
REFERENCES Jordan RE. Esthetic composite bonding: techniques and materials.Toronto/Philadelphia: BC Decker, 1988.