Aesthetic Correction of a Damaged Occlusion Using Ceramic and Ceramometal Restorations

Occlusal damage may be caused by a variety of factors including primary and secondary malocclusion, parafunctional habits, missing teeth, caries, and failing restorations, among others.^1-10 In many cases, patients who experienced previous trauma in a dental environment may be reluctant to seek treatment, despite infection, facial swelling, pain, and poor aesthetics. In these cases, challenges lie in getting the patient to accept treatment (ideally through education), using sedative drug therapy when necessary, and mechanically rebuilding the damaged dentition. This should be done with preservation of the maximum amount of tooth structure wherever possible. Conservative restorative preparation is the hallmark of responsible dental care: minimally invasive, atraumatic restorative treatment by virtue of minimal tooth reduction where applicable.¹¹
In cases involving a variety of preparation designs, minimal tooth reduction for all-ceramic restorations offers many benefits. The benefits include a reduced potential for fracture of the ceramic restoration¹² and the avoidance of exposing sensitive tooth structure, thus preventing postoperative sensitivity.13 In addition, maximum preservation of tooth structure imparts superior bond strengths and increased strength to the general tooth structure. For complete ceramometal restorations, traditional, aggressive tooth reduction must be followed to achieve ideal anatomy and aesthetics and to allow for both the thickness and strength of the gold coping and the covering ceramic.
The following case report demonstrates the restoration of a dentition severely damaged due to caries, using a material that allows maximum preservation of tooth structure.

CASE REPORT
Materials

LUMINEERS by Cerinate (Den-Mat Holdings), a material for laboratory-fabricated indirect restorative material, has been successfully used in treating diverse preparation methodologies. Cerinate porcelain is a uniquely processed feldspathic porcelain that achieves sufficient strength to create thicknesses as low as 0.2 mm, ideal for minimally invasive veneers. It also has a wide variety of applications as a porcelain used to fabricate many other types of ceramic restorations, including all-ceramic full crowns, three-fourths crowns, inlays and onlays, as well as the ceramic for porcelain-to-metal full crowns. Cerinate porcelain has been extensively studied for more than 20 years^14-17 and demonstrates exceptional longevity and strength.¹⁸
The flexural strength of Cerinate porcelain falls in a range typically occupied by aluminum oxide-reinforced core porcelains.¹⁹ Its low coefficient of thermal expansion, which is similar to tooth enamel, prevents fracturing and debonding. Cerinate porcelain has been used in a number of applications including veneering to aesthetically compromised natural teeth,²⁰ veneering to existing unaesthetic crowns,^21,22 3-unit fixed anterior prostheses,²³ periodontal prostheses,²⁴ regaining cuspid guided occlusion,²⁵ diastema closure,²⁶ inlays,²⁷ onlays,^28,29 and crowns.^20-22

Phase 1: The Consultation

Figure 1. The patient presented with rampant caries, damaged occlusion, infection, and poor aesthetics.

The patient, a 30-year-old female, presented with rampant caries, infection, and damaged occlusion, in addition to a chief complaint of severe pain and swelling under her right eye and upper right cheek. She reported having root canal therapy in her upper right lateral incisor, canine, and first premolar (Figure 1). Emergency examination determined that there was swelling in the area apical to the right canine and infraorbital space. This was due to persistent infection from a poor seal between the temporary restorations and the root canal access openings in these teeth.

Phase 2: Provisional Treatment

Figure 2. Full-coverage crown preparations using prefabricated glass fiber posts and white shaded and natural dentin automix core build-up material.

Following a course of antibiotic therapy, the root canals were retreated and then restored using prefabricated glass fiber posts (Core-Post [Den-Mat Holdings]) and white shaded or natural dentin automix core build-up material (Core Paste XP [Den-Mat Holdings]; Figure 2). Following crown preparation, provisional restorations were fabricated and then temporarily cemented to the newly created abutments.
A complete examination was performed, including a full-mouth series using digital radiography (Trophy RVG [Kodak Dental Systems]) and study models. It was determined that existing nontreated teeth in the upper and lower arches had carious lesions with potential for invasion into the root canal systems. Periodontal examination and temporoman-dibular analysis was within normal limits despite the loss of all molars in the upper right quadrant.
Based on these findings, a treatment plan was created that would restore the damaged incisal surfaces and existing carious lesions, correct the aesthetic deficiencies, and enhance the occlusion, all with minimal tooth reduction. Initially, preventive resin restorations and provisional crowns would be fabricated where needed, following complete caries removal. The patient was placed on a strict home-care hygiene regimen that included the use of a 1.1% neutral sodium fluoride dentifrice (Control Rx [Omni Preventive Care/3M ESPE]) and a remineralization paste (Prospec MI Paste [GC America]).
Osseous and soft-tissue crown lengthening were to be performed on the facial tissue of the upper left lateral incisor, canine, and first premolar. All posterior teeth requiring full-coverage restorations were to be restored with stacked Cerinate porcelain-to-precious gold crowns. The remaining teeth were to be restored using stacked Cerinate porcelain in a variety of preparation designs including minimally invasive veneer preparation designs, reverse three-fourths crowns, and full-coverage crowns.
The teeth in the maxillary arch were locally anesthetized, and the gross carious lesions were treated with direct composite restorations. Due to their close pulpal proximity, the lesions were initially restored with a pulpal protective base (Geristore Syringeable [Den-Mat Holdings]), a resin reinforced glass ionomer in a dual-cartridge delivery system. Because of its histological biocompatibility^30,31 and kindness to the pulp,³² Geristore is an ideal restorative material in deep carious lesions. In addition, Geristore is the only material that allows a “bond” to the periodontal ligament via long junctional epithelial attachment, and is kind and gentle to commonly reactive pulpal tissue. This was followed by restoring these teeth with resin restorations that would help establish the aesthetic design for the future lab-fabricated ceramic restorations.

Phase 3: Definitive Treatment, Maxillary Arch

Figure 3. Attached gingival tissue is sculpted to correct aesthetic contours.	Figure 4. The site immediately following flap reflection, osseous recontouring, and suturing.
Figure 5. The tissue was evaluated for complete healing.	Figure 6. All remaining minor carious lesions were removed during the full and partial fixed-coverage tooth preparations.
Figure 7. The provisionals following trimming, occlusal verification, adjustment, and polishing.	Figure 8. The definitive LUMINEERS by Cerinate Porcelain stacked all-ceramic restorations.
Figure 9. The definitive LUMINEERS by Cerinate Porcelain stacked porcelain-to-precious gold fixed restorations.	Figure 10. The definitive LUMINEERS by Cerinate Porcelain stacked porcelain-to-precious gold fixed restorations.

Soft-tissue crown lengthening was performed on the facial tissue of the upper left lateral incisor, canine, and first premolar by sculpting the gingival attached tissue to correct aesthetic contours using the Bident Bipolar IntraOral Surgical System (Synergetics/Valley Forge Scientific; Figure 3). A full-thickness flap was reflected and osseous tissue was contoured apically to satisfy the demands for biological width. The flap was then sutured to place (Figure 4).
At the next appointment, the tissue was evaluated for complete healing (Figure 5).  At this time, all remaining minor carious lesions were removed during the full and partial fixed-coverage tooth preparations (Figure 6). A final impression was made using a Three-Quarter Arch Triple Tray (Premier Dental) with LUMINEERS Impressions polyvinyl siloxane impression material (Den-Mat Holdings). A heavy-body fast-set base impression was made, followed by the use of light-body fast-set wash as prescribed by the H&H impression technique.³³ Provisional restorations were made by using a prefabricated vacuform shell with a methacrylic composite shade B1 (Gorgeous Temp [Den-Mat Holdings]), an exceptionally strong dual-cured nanohybrid methacrylic composite temporary material. After curing intraorally for 5 minutes, the shell was removed, the provisionals were trimmed, and the occlusion was verified, adjusted, and polished (Figure 7).
The definitive veneer and full-crown restorations were received from the Cerinate Smile Design Studio in bleach shade B0. The veneers were LUMINEERS made with Cerinate Stacked Porcelain (Figure 8). The full crowns were porcelain-to-gold, and were also made with Cerinate porcelain (Figures 9 and 10). Cerinate porcelain was selected because it enables tooth restoration with minimal preparation. The all-ceramic restorations were pre-etched in the Studio by first sandblasting with aluminum oxide followed by chemical etching with hydrofluoric acid.
With the patient seated, Porcelain Conditioner (Den-Mat Holdings) was applied to the intaglio surfaces of the all-ceramic restorations for 30 seconds, rinsed, and dried. This product is a citric acid ceramic pretreatment used to increase the surface tension of the porcelain. This in turn activates and hydrolyzes the Cerinate Prime, a silane-coupling agent that is then immediately ap-plied to these surfaces for 30 seconds and gently air-dried. The provisional restorations were removed and the maxillary teeth were cleaned, rinsed, and dried. The preparation of the intraoral surfaces required bonding to 2 different substrates: existing enamel/dentin and resin-based core build-up materials. The resin cores were acid-etched for 2 minutes using PorceLock (Den-Mat Holdings), a pH-neutral, biocompatible hydrofluoric acid, rinsed, and dried. Den-tin and enamel surfaces were etched for 20 seconds with Etch ’N’ Seal (Den-Mat Holdings), a 25% phosphoric acid gel containing oxalate crystals designed to prevent acid-etch-induced sensitivity. They were then rinsed and dried. Porcelain Conditioner was applied to the composite cores for 30 seconds, rinsed, and dried, and then Cerinate Prime silane was applied to these surfaces and dried. Tenure A and B (Den-Mat Holdings), a 2-bottle chemical-curing, multipurpose adhesive system, was applied in 5 coats to all surfaces, followed by the application of Tenure S (Den-Mat Holdings), a single-component, light-cured, hydrophilic agent that further enhances bonding. For the past 2 decades, the Tenure system has demonstrated a proven clinical record of high bond strengths,³⁴ excellent retention,³⁵ significant reduction of microleakage,³⁶ and reduction of postoperative sensitivity. These characteristics can be attributed to the formation of a hybrid zone37 that can eliminate root sensitivity instantly. The easy, 2-step process of Tenure A and B and Tenure S exhibits bond strengths to dentin of more than 20 MPa.
Infinity (Den-Mat Holdings), a dual-cure, resin-reinforced glass ionomer cement, was dispensed from an automix syringe directly into the porcelain-to-gold crowns and seated to place. The seated crowns were light-cured at the margins for 3 seconds each, and the excess Infinity cement, now in a gel-like state, was easily removed with a scaler. After 60 seconds the excess interproximal cement was removed by floss.
The all-ceramic laboratory-fabricated restorations were tried in using Ultra-Bond Try-In Paste Supreme White Shade (Den-Mat Holdings), a noncure try-in resin. The excess try-in paste was removed, and the overall aesthetic scheme was evaluated. Using a large photographic mirror, the maxillary anterior teeth were evaluated from the incisal. This provides a view of tooth contours in the vertical and horizontal, as well as arch form, tooth width, and rotations, among others. The patient was then given a mirror in order to evaluate her new smile. Once it was agreed that the restorations were excellent from an aesthetic perspective, they were removed, and the majority of the Try-In paste was removed with a resin-saturated applicator (Tenure S). Since Ultra-Bond Try-In Paste has all the chemical components of a bonding cement minus the photo or chemical bond initiators, any remaining microlayer is incorporated into the final dual-cure composite cement, and therefore need not be entirely removed. The restorations were then set aside and the teeth were prepared for cementation.
The all-ceramic restorations were cemented to place by dispensing Ultra-Bond Plus Supreme White shade (Den-Mat Holdings) resin cement. Ultra-Bond Plus is a multi-purpose, dual-cure resin cement designed specifically for bonding porcelain restorations. A study has evaluated Cerinate veneers 17 years after initial placement.¹⁴ This study showed that the Cerinate porcelain veneers exhibited no evidence of microleakage, gingival recession, cracks, or fractures.
The restorations were all seated to place, and excess cement was removed using an applicator brush saturated with an unfilled resin (Visar Seal [Den-Mat Holdings]). Each restoration was then firmly seated by directing gentle pressure from the incisal and facial aspects simultaneously until a thin bead of resin cement was expressed from the marginal areas. The Cerinate porcelain restorations were held in this fashion and light-cured for 3 seconds each using the Sapphire Curing Light (Den-Mat Holdings), a versatile plasma arc curing light known for deep penetration and rapid, 3- to 5-second curing ability. In a study by Watanabe,³⁸ the bond strength achieved by plasma arc curing was found to be relatively unaffected by the shade or opacity of porcelain. It was found that plasma arc curing for 6 seconds was sufficient to obtain bond strengths similar to those of specimens polymerized with halogen light for 40 seconds.
Once cured, any remaining Ultra-Bond Plus resin cement was first removed from the facial aspects using the Schure 349 (Den-Mat Holdings), a nonscratching resin removal hand instrument. The remaining resin cement was removed at the margins and interproximal contacts using the 042016100 mosquito-shaped diamond bur (LUMINEERS Finishing Kit [Den-Mat Holdings]). The often flake-like remaining translucent resin cement was removed from the facial surfaces using an 041610100 polishing cup (LUMINEERS Finishing Kit). Interproximal contacts were opened using the CeriSaw (Den-Mat Holdings), a stainless steel 0.05-mm serrated blade that cuts resin cement but not tooth enamel or porcelain. The CeriSaw was placed at a 45⁰ angle to the incisal plane of the interproximal junctions and gently rocked in a seesaw fashion toward the gingival until the cement bond was separated. Any remaining interproximal resin was removed and polished using the CeriSander (Den-Mat Holdings), a single-sided diamond-coated interproximal strip that utilizes the same handle as the CeriSaw.

Figure 11. The maxillary case immediately following insertion.	Figure 12. The maxillary case from an occlusal view.

Occlusal adjustment was accomplished with a 049018100 football-shaped diamond bur (LUMINEERS Finishing Kit), using care to ensure that proper canine protected oc-clusion, anterior guidance, and occlusal contacts were correct. The adjusted areas were polished using a 1-µm diamond Porcelain Laminate Polishing Paste (Den-Mat Holdings) with a latch-driven goat hair brush (Jiffy Goat Hair Brush [Ultradent Products]). The patient was placed on a home-care program and given a 24-hour follow-up appointment for any adjustments (Figures 11 and 12).

Phase 4: Definitive Treatment, Mandibular Arch

Figure 13. The definitive LUMINEERS by Cerinate Porcelain stacked all-ceramic and porcelain-to-precious gold fixed restorations.	Figure 14. An occlusal view of the lower arch immediately following insertion.
Figure 15. A fully retracted view of the completed case.	Figure 16. A portrait view with the patient’s healthy, new smile.

Figure 17. A close-up view of the final result. The patient can’t stop smiling.

At a subsequent appointment, the teeth in the lower arch were prepared in a similar fashion to the teeth in the maxillary arch. The remaining minor carious lesions were removed during tooth preparation for the full and partial fixed-coverage fixed restorations. As previously described, a final impression was made using a Three-Quarter Arch Triple Tray with LUMINEERS Impressions Polyvinyl Siloxane impression material. Provisional restorations were again made using a prefabricated vacuform shell with shade B1 Gorgeous Temp. After curing intraorally for 5 minutes, the shell was removed, the provisionals were trimmed, and the occlusion was verified, adjusted, and polished.
The definitive restorations were received from the Cerinate Smile Design Studio in bleach shade B0. The veneers were LUMINEERS made with Cerinate Stacked Porcelain. The full crowns were porcelain-to-gold, also made with Cerinate porcelain (Figure 13). As previously described, the ceramic restorations were treated in the Studio and then chairside with the patient present. The provisional restorations were removed and the mandibular teeth were cleaned, rinsed, and dried. The preparation, bonding, clean-up, occlusal adjustment, and polishing were accomplished as described for the upper arch (Figures 14 to 17).

Conclusion

When treating a severely damaged dentition, there are many preparation designs and restorative choices available. The advantages of combining the best of restorative materials to suit the needs of the tooth preparation, and not vice-versa, are the exemplar of exceptional care. When combined with Cerinate porcelain, a porcelain with natural-appearing aesthetics, great strength, and reliability in high-stress occlusal situations, the rewards are many.

References

Dr. Shuman maintains a full-time general, reconstructive, and aesthetic dental practice in Pasadena, Md. Since 1995 Dr. Shuman has lectured and published on advanced, minimally invasive techniques; he has taught these procedures to thousands of dentists and developed many of these methods. He has published more than 65 articles on topics including creating cosmetic smiles, adhesive resin dentistry, and minimally invasive restorative and cosmetic dentistry. He is a Master of the AGD, a Fellow of the Pierre Fauchard Academy, a member of the ADA, and was named one of the Top Clinicians in Continuing Education from 2005 to 2008 by Dentistry Today. To have Dr. Shuman speak at your next seminar or to order educational materials, call (877) 4-SHUMAN or visit ianshuman.com.

Disclosure: Dr. Shuman has not received any compensation for the preparation of this article.