Synergy in Dentistry - Vol.3, No. 1, 2005 · niques in dentistry. The foundation of accuracy and...

in Dentistry

Published by Ascend Media’s Dental Learning Systems as a Supplement to Contemporary Esthetics and Restorative Practice®

©2005. Ascend Media, LLC

SynergyThe alliance between the dentist and lab technician

Predictable Esthetic Results From the Placement of an

Anterior 3-unit, All-ceramic CAD/CAM Restoration

A Multidisciplinary Approach to Replacing Fractured Porcelain and Correcting Worn Dentition With Zirconia

All-ceramic Crowns and Feldspathic Veneers

Sponsored by 3M ESPE70-2009-3724-4

March 2005 Vo l . 3 , No . 1 , 2005

An Ascend Media Publication

Dear Readers:Computer-aided design and computer-assisted

manufacturing (CAD/CAM) has gained wide-spread use in a number of disciplines and tech-niques in dentistry. The foundation of accuracyand precision is a central theme that is associatedwith CAD/CAM in dentistry and other industrialuses. The materials used with CAD/CAM proce-dures in dentistry can vary from original ceramics,polymers, or the newer zirconium-based ceramiccore substrates.1-3

The interest in systems such as the Lava™

Crowns and Bridges System from 3M ESPE is rein-forced by the potential for an alternative to alloysubstrates where esthetics is a primary concern. Inaddition, all-ceramic substrates offer an estheticalternative to patients who have allergies to certainalloys, such as nickel or chromium. Based on theuse of zirconium, Lava crowns and bridges are show-ing promise where traditional porcelain-fused-to-metals previously dominated the profession.4,5

This issue of Synergy in Dentistry presents arti-cles with a focus on the Lava System used in fixed-bridge and full-coverage crown applications. Dr.Michael Davenport discusses critical clinical pro-cedures that should be used to ensure a successfulprosthesis. Within this article, Ms. MichelleRobinson provides perspectives from the laborato-ry. Dr. Wesley Urich presents a multidisciplinaryapproach to replacing fractured porcelain and cor-recting worn dentition using Lava crowns.

Also in this issue, a panel of well-respecteddentists and technicians involved with ceramicsystems addresses frequently asked questions. Theyoffer their insight on issues important to a clini-cian who elects to use zirconium core systems suchas Lava crowns and bridges.

After reading this issue of Synergy you shouldhave a better understanding of the indications andproper details of using Lava crowns and bridges inrestorative cases. Dental Learning Systems wouldlike to thank 3M ESPE for supporting this impor-tant supplement.

Sincerely,

E. Steven Duke, DDS, MSDChief, Dental ServiceCentral Texas Veterans HealthCare SystemTemple, Texas

in DentistrySynergyThe alliance between the dentist and lab technician

Jeff J. Brucia, DDS E. Steven Duke, DDS, MSDLee Culp, CDT

MARCH 2005ADVISORY BOARD

David Grin, CDT Gerard Kugel, DMD, MSDavid S. Hornbrook, DDS

Edward A. McLaren, DDS Matt RobertsMoshe Mizrachi, CDT

References1. Cramer von Clausbruch S, Faust A. Advanced crown and bridge design. Int J

Comput Dent. 2003;6:293-302.

2. McLaren EA, Terry DA. CAD/CAM systems, materials, and clinical guidelines forall-ceramic crowns and fixed partial dentures. Compend Contin Educ Dent.2002;23:637-641, 644, 646.

3. Oilo G, Tornquist A, Durling D, et al. All-ceramic crowns and preparation charac-teristics: a mathematic approach. Int J Prosthodont. 2003;16(3):301-306.

4. Suttor D, Bunke K, Hoescheler S, et al. LAVA--the system for all-ceramic ZrO2crown and bridge frameworks. Int J Comput Dent. 2001;4(3):195-206.

5. Suttor D. Lava zirconia crowns and bridges. Int J Comput Dent. 2004;7(1):67-76.

John A. Sorensen, DMD, PhD Thomas F. Trinkner, DDSBruce Small, DMD

This supplement to Contemporary Esthetics and Restorative Practice® was supported by an educational grant from 3M ESPE. To order additional copies call 800-926-7636, ext.180. D535

Senior Vice President of Medical/Dental Divisions, Daniel W. Perkins; Vice President and Group Publisher, Anthony Angelini; Chief Operating Officer, Medical andDental Group, Robert Issler; Editorial Director, Special Projects, Brian Benbrook; Senior Associate Projects Editor, Lisa M. Neuman; Projects Coordinator, DawnLagrosa; Associate Editor, Lee Ann Pastorello; Copy Editor, Jill Olivero; Design Director, Special Projects, Wayne Williams; Projects Director, Susan M. Carr; Directorof Quality Assurance, Barbara Marino; Director of Production and Manufacturing, Elizabeth Lang; North East Regional Sales Manager, JeffreyE. Gordon; West Coast Regional Sales Manager, Michael Gee; Executive Assistant, Tricia McCormick; Executive and Advertising Offices,Ascend Media, LLC, 241 Forsgate Drive, Jamesburg, NJ 08831-1676, Phone (732) 656-1143, Fax (732) 656-1148.

Contemporary Esthetics and Restorative Practice® is published 12 times a year by Ascend Media, LLC, 241 Forsgate Drive, Jamesburg, NJ08831-0505. Copyright © 2005. Ascend Media, LLC. Printed in the USA. All rights reserved. No part of this issue may be reproduced inany form without written permission from the publisher. Ascend Media Corporate Officers: President & CEO, Cameron Bishop;Executive Vice President & CFO, Dan Altman; Executive Vice President, Sales & Marketing, Ron Wall.

Contemporary Esthetics and Restorative Practice® is a registered trademark of Ascend Media, LLC.

The views and opinions expressed in the articles appearing in this publication are those of the author(s) and do not necessarily reflect the views or opinions of the edi-tors, the editorial board, or the publisher. As a matter of policy, the editors, the editorial board, the publisher, and the university affiliate do not endorse any products,medical techniques, or diagnoses, and publication of any material in this journal should not be construed as such an endorsement.

WARNING: Reading an article in Synergy in Dentistry does not necessarily qualify you to integrate new techniques or procedures into your practice. ContemporaryEsthetics and Restorative Practice® expects its readers to rely on their judgment regarding their clinical expertise and recommends further education when necessarybefore trying to implement any new procedure.

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T a b l e o f c o n t e n t s

Predictable Esthetic Results From the Placement of anAnterior 3-unit, All-ceramic CAD/CAM Restoration .......... 4Michael Davenport, DMD

Lab Dialogue .................................................................................. 10Ed McLaren, DDS; Matt Roberts; Gordon Russell, RDT; Bob Winter, DDS

Scientifically Speaking ................................................................ 14

A Multidisciplinary Approach to Replacing FracturedPorcelain and Correcting Worn Dentition With Zirconia All-ceramic Crowns and Feldspathic Veneers........................ 16Wesley J. Urich, DDS

4 Synergy in Dentistry www.3MESPE.com/synergy Vol. 3, No. 1, 2005

Michael Davenport, DMDPrivate PracticeLexington, South Carolina

Clinical Instructor Medical College of GeorgiaAugusta, Georgia

Visiting FacultyPalmetto Richland Memorial HospitalColumbia, South Carolina

Teaching AssistantThe LD Pankey InstituteKey Biscayne, Florida

Over the past decade, some materials used forall-ceramic or metal-free dentistry havefared favorably, while others have not fared

as well. In this author’s practice most problemshave occurred in multiple-unit restorations, butsingle-unit cases have not been immune to failures.

Recent advancements in the composition andprocessing of all-ceramic materials and restorations

have resulted in more predictable multiple-unitcases.1 Although currently available technologydoes not recommend fabrication and subsequentplacement of restorations comprised of more than 4units, 3- and 4-unit bridges can now be created andseated with confidence.

Material DescriptionIn recent years, computer-aided design/comput-

er-aided manufacturing (CAD/CAM) materialshave been introduced into the marketplace for thefabrication of 3- and 4-unit bridges. One of themore promising materials, Lava™ Crowns andBridgesa, became available in 2003. Lava is a zirco-nia oxide product milled from various blocks,depending on the number of units desired. As aresult of its proven record in other industrial areas,zirconia oxide is emerging in the dental industry

Predictable Esthetic Results From the Placement of an Anterior 3-unit, All-ceramicCAD/CAM Restoration

AbstractThe drive for all-ceramic or metal-free den-

tistry has had its ups and downs over the past decade. However, computer-aideddesign/computer-aided manufacturing (CAD/CAM) materials have been introduced into themarketplace for the fabrication of single-unitrestorations and 3- and 4-unit bridges. Thesematerials hold promise for predictably satisfy-ing the need for esthetic and strong restorationsfor such indications. Proper case selection forsuch all-ceramic restorations—as well asadhering to standard clinical protocol forpreparation design, impression-making, andcementation—is essential. This article pre-sents a case in which an anterior 3-unit, all-ceramic CAD/CAM bridge (Lava™ Crownsand Bridges System) was used to replace a pre-viously placed porcelain-fused-to-metal bridge.

Figure 1—Preoperative facial view of thepatient in full smile.

Figure 2—Preoperative right lateral view ofthe patient showing the existing porcelain-fused-to-metal bridge restoration betweenteeth Nos. 5 and 7.

Figure 3—Preoperative left lateral view of thepatient.

a3M ESPE, St. Paul, MN 55144; 800-216-9502

5Vol. 3, No. 1, 2005 www.3MESPE.com/synergy Synergy in Dentistry

and, when combined withCAD/CAM technologies, holdspromise based on its materialproperties and clinical perfor-mance for use in the fabricationof bridge restorations.1

Clinically speaking, whenLava restorations are prescribed,a traditional impression is madeand stone models are poured.The dies are then scanned in thelaboratory and, ultimately, thecore of the desired restoration(s)is milled by the CAM millingprocess. The framework can thenbe colored with 7 differentdentin or stumpf shades, whichallows for a greater spectrum ofbase colors. The resulting frame-work is then sintered for 11 hours

at 1,500°C. Surface porcelainsare then layered or pressedaccordingly, providing the tech-nician with the ability to createlifelike restorations. Because thesintered substructure is so thin(only 0.4 mm), laboratory ceram-ists have another 1 to 1.5 mmavailable with which to impartthe desired color and estheticqualities.

According to the manufac-turer, Lava material is extremelystrong, demonstrating a flexuralstrength of more than 1,200MPa.2

Case ReportA 47-year-old woman pre-

sented desiring replacement of a

porcelain-fused-to-metal (PFM)bridge between teeth Nos. 5 and7, which replaced a congenitallymissing cuspid (Figures 1 through9). This fixed partial denture hadbeen in place for more than 20years and showed signs of wearand poor margination. The fa-cial gingival tissue also demon-strated signs of chronic inflam-mation (Figures 5 through 9).The patient was not interestedin orthodontic treatment or im-plants, so the treatment planincluded replacement of the 3-unit bridge with a more estheticalternative.

A thorough occlusal exami-nation was performed thatrevealed a class I molar relation-

Figure 4—Retracted view of the patient incentric occlusion.

Figure 5—Retracted right lateral view of thepatient. Note the diastema mesial of tooth No. 7and poor margins with associated inflammation.

Figure 6—Retracted left lateral view of thepatient.

Figure 7—Close-up preoperative view of thepatient’s anterior dentition. Note the surfacetexture and high gloss of the central incisors.

Figure 8—Close-up preoperative left lateralview of the patient’s dentition.

Figure 9—Close-up preoperative right lateralview of the patient’s existing porcelain-fused-to-metal bridge restoration.

Figures 10 and 11—Preoperative shades were taken for shade mapping. Figure 12—View of the preparations of teethNos. 5 and 7 after removal of the porcelain-fused-to-metal bridge.

ship with a slight centric rela-tion-centric occlusion discrep-ancy, which was equilibrated.Because a smooth group func-tion in lateral excursion couldeasily be achieved and main-tained, it was possible in thiscase to place a 3-unit bridgerestoration fabricated with anall-ceramic material. After con-ferring with the dental laborato-ry about this case, a Lava bridgewas chosen as an appropriaterestorative material.

Necessary preoperative shademapping was completed, andphotographs were taken to docu-ment the adjacent tooth mor-

phology and texture (Figures 10and 11). After removing theexisting PFM bridge, slight tissuecontouring was performed usingelectrosurgery.

Because a bridge had alreadybeen in place, the preparationdesign for this case was limited torefining the existing preparations(Figure 12). Normally, however,a 1.5-mm, 360° reduction wouldbe completed, with a 1.5-mm to2-mm reduction on the incisal orocclusal aspects. As with any all-ceramic fixed partial denture, allangles were kept rounded andsmooth. A dentin or “stumpf”shade was taken (Figure 13), and

the pontic site was prepared withdiamonds and treated withViscoStat® Plusb (Figure 14).Because of its excellent hemosta-sis, this author has found the pro-cedure of tissue contouring withdiamonds followed by applica-tion of ViscoStat Plus to beextremely effective.

A final impression was takenusing a combination of Imprint™

IIa heavy body and Provil® novoc

light body vinyl polysiloxanematerials. A lower arch impres-sion, facebow, and bite registra-

Figure 13—A stumpf shade was takenagainst the preparations.

Figure 14—The pontic site was prepared withdiamonds and treated with ViscoStat Plus.

Figure 15—After tooth preparation, a preoper-ative tooth shade against the central incisorswas again taken and photographed.

Figure 16—A 1:1 photograph of the centralincisors was taken to demonstrate for the lab-oratory the internal and external tooth charac-terizations.

Figure 17—Postoperative view of the maxil-lary arch form.

Figure 18—Postoperative occlusal view. Notethe occlusal anatomy and staining.

Figure 19—RelyX Unicem Self-adhesiveUniversal Resin Cement was used to seat theLava 3-unit bridge restoration.

Figure 20—Postoperative occlusal view of thefinal Lava 3-unit, all-ceramic restoration.

Figure 21—Postcementation close-up 1 weekpostoperatively. Note the positive tissueresponse. Also note the surface texture andcharacterization; the pontic of tooth No. 6appears like a natural tooth.

bUltradent Products, Inc, South Jordan, UT 84095;800-552-5512

cHeraeus Kulzer, Inc, Armonk, NY 10504; 800-431-1785


tion also were taken, as well asdigital photographs of the preop-erative tooth shade (Figures 15and 16). The photographs facili-tated shade matching and alsoassisted the technicians in deter-mining the appropriate contour,texture, and value of the antici-pated Lava restoration.

Cementation AppointmentThe laboratory returned 2

bridges for try-in because ofquestions regarding surface col-oration. Both bridges were triedin, and the patient—guided bythe dentist—ultimately decidedon one of the two. Marginalintegrity was excellent, as weretexture, contour, and color. Mostimportantly, the correct value ofthe restorations was obtained. Itis this author’s opinion that

value is much easier to matchwith all-ceramic restorationsthan traditional PFM crowns.

Slight occlusal adjustmentswere made to ensure group func-tion on the bicuspid and thecuspid and to achieve a smoothcrossover (Figures 17 and 18).When a patient presents with amissing cuspid, it has been thisauthor’s experience that theguidance should be shared inimmediate rise as well as incrossover. By sharing the excur-sive movements with 1 or 2bicuspids and the incisors, thestress to the restoration is less-ened. With less stress, the suc-cess of an all-ceramic system ismuch more predictable.

After polishing, the bridgewas then cemented with RelyX™

Unicem Self-adhesive Universal

Resin Cementa (Figure 19). Thiscement was selected because ofits dual curing capabilities andadhesive qualities. It cleans upeasily and is an excellent choicewhere there are subgingival mar-gins. (When seating Lava resto-rations, adhesively bonded ce-ments are not always necessary.3)

ConclusionThe availability of materials

that enable the dentist to give hisor her patients excellent esthet-ics with reliable strength is now areality with Lava crowns andbridges. Through the use of thistruly CAD/CAM system, thelaboratory’s fabrication time isshortened as a result of a millingcenter that creates a frameworkfor subsequent surface porcelain

LabProcessMichelle RobinsonTeam Aesthetic SeminarsIdaho Falls, Idaho

Before a substructure canbe fabricated, the pre-pared case must be eval-

uated for adequate reductionand the pontic site needs to bemodified on the model. For thebicuspid, occlusal and buccal

reduction of 1.5 mm to 2 mmand a 1-mm shoulder are idealto obtain the desired results. Forthe cuspid and lateral, a 1-mmshoulder, 1 mm to 1.5 mmfacially, and 1.5 mm to 2 mmincisally should be obtained(Figures 1 and 2).

The substructure is 0.5 mmthick with a connector size of 9 mm2 for the posterior bridgesand 7 mm2 for the anteriorbridges.

After receiving the Lava™,a

bridge substructure, the coping

fit was checked back to thepinned and the solid models.The occlusal clearance waschecked on mounted modelsand the connector size wasslightly adjusted to its minimalthickness, moving the connec-tors lingually where possible toallow for interproximal embra-sures. After evaluation andadjustments of the framework,stumpf dies were made to dupli-cate the underlying dentition(Figure 3).

Figure 4 is an example of the

Figure 1 Figure 2

a3M ESPE, St. Paul, MN 55144; 800-216-9502

Continued on Page 9


Continued on Page 8

illumination of a substructure.The substructure was then

sandblasted with a 50-µm alu-minum oxide and steamed toremove any contaminants. Thestumpf dies were wetted withLava™ Cerama stain/glaze liquidso that there was no air trappedbetween the dies and the frame-work. This ensures that anyinfluence of the underlyingshade will be accounted forwhen doing an initial stain ofthe framework. A frameworkmodifier was applied in aneven coat, approximately 0.1mm to 0.2 mm thick, over theentire surface of the structure toaugment the base shade of thezirconia substructure. This creat-ed the base shade for the finalrestorations (Figure 5).

The modifier was placed into the interproximal areas foradded depth and onto the neckareas to blend the restorationsinto the natural dentition, mak-ing the margin areas lessnoticeable if there is any futuregingival resorption. The frame-work was then fired. The dentinporcelain was mixed with dis-tilled water on a wet tray andapplied by brush. An incisaledge matrix of the provisionalswas used to monitor the place-ment of the dentin material. Acombination of diluted dentinand incisal porcelains was thenlayered onto the dentin aroundthe incisal, buccal, and inter-proximal areas, building therestorations to full contour

(Figure 6).The matrix was removed

from the opposing model andfunction was checked. Theocclusal surface of the bicuspidwas created using a smallamount of the Lava Ceram No.15 magic intensive in the fossaarea for depth and the E5enamel over the top to createthe primary and secondaryanatomy. Centric and excursivemovements were checked andthe bridge was removed fromthe model work. Interproximalsurfaces were touched up withthe dentin porcelain and thebridge was then fired (Figure 7).

On the final build, additionalchroma was added around theneck of the units; deficient areasof the pontic were corrected;and the entire surface was lay-ered over with a combination ofenamels and clear porcelains toform the final shape (Figure 8).

After firing, the final con-tours, contacts, and occlusionwere touched up and a slighttuning of the surface anatomywas done. The restorations werethen glazed and polished tomatch the adjacent surface lus-ter (Figures 9 and 10).

Before the case was sent fordelivery, the internal areas ofthe framework were cleaned by using the 50-µm aluminumoxide.

AcknowledgmentFigures 1 and 2 were provid-

ed by 3M ESPE.

Figure 4 Figure 5

Figure 6

Figure 3

Figure 7

Figure 8

Figure 10

Figure 9


application.4 The end result is astrong, very esthetic nonmetalalternative for single- and multi-ple-unit cases.

The strength of Lava restora-tions, in this author’s experience,has been excellent, and allrestorations have demonstratedexcellent marginal integrity.Additionally, this author hasfound that the esthetics demon-strated by these restorations hasbeen significantly better thanthat of PFM restorations (Figures20 through 26).

Choosing the best cases forwhich to place Lava restorationsis essential. For fixed partial den-tures, Lava bridges are indicatedfor 3 units and up to 4 units, andconsiderations for such casesinclude the occlusion and loca-tion in the mouth. According tothe manufacturer, Lava bridgerestorations are suitable ideallyfrom first molar to first molar.

Additionally, there must be suffi-cient gingivo-incisal height andbuccolingual width to ensureproper strength. Therefore, casesin which there are very shortteeth or where there is substan-tial buccal or lingual tooth lossshould not be chosen for Lavarestorations.

References1. Suttor D. Lava zirconia crowns and

bridges. Int J Comput Dent. 2004;7:67-76.2. Golden PF. The Lava CAD/CAM

System—advanced technology promisesimproved metal-free performance andesthetics. Contemporary Esthetics and

Restorative Practice. November 2002;6:84-87.

3. Kurbad A. Clinical aspects of all-ceram-ic CAD/CAM restorations. Int J ComputDent. 2002;5:183-197.

4. Sorensen JA. The Lava all-ceramic sys-tem: leading the way into the new mil-lennium with digital dentistry. Synergy inDentistry. June 2002;1:10.

Dr. Davenport graduated from the MedicalUniversity of South Carolina DentalSchool in 1979 and completed a generalpractice residency there in 1981. He wasthe Associate Director of Dental Educationat Richland Memorial Hospital (Columbia,South Carolina) from 1981 through 1998.He has maintained a private practice inLexington, South Carolina, since 1996.

Figure 22—Right lateral view of the Lava 3-unit, all-ceramic bridge restoration in centricocclusion.

Figure 23—View of the patient’s right workingmovement. Note the use of group function toremove stress from the cuspid pontic.

Figure 24—View of the patient’s rightcrossover. Note that the lateral and centralincisors are picking up the lateral excursivemovement.

Figure 25—Postoperative right lateral view ofthe patient’s smile exposing the new Lava 3-unit, all-ceramic restoration.

Figure 26—Postoperative view of the patientin natural smile.


Synergy in Dentistry www.3MESPE.com/synergy Vol. 3, No. 1, 2005

QHow is zirconia different and how doesit compare to traditional all-ceramics?

ADr. McLaren: Zirconia as it is currently usedin dentistry is a solid sintered polycrystalline

structure that has no glassy phase. It can be fabri-cated by one of several CAD/CAM systems.Structurally, it is similar to the densely sinteredalumina used in the conventional Procera® tech-nique. Zirconia has a much higher fracture tough-ness and flexural strength than even Procera® alu-mina. This is in part because of a uniquemechanism in zirconia called “transformationtoughening” that other ceramics don’t possess. It isa crack “healing” property, in which zirconia grainsabsorb energy and “transform” from a tetragonalform of crystal to a monoclinic form of crystal. Themonoclinic form is slightly larger and can close offsmall cracks. Zirconia is roughly 2 times tougherand stronger than alumina and 5 to 10 timestougher than glass-based ceramics.

Mr. Roberts: Zirconia gives us a ceramic materi-al that can be very esthetic, yet can be placed withconventional cementation. This allows the use ofall-ceramic restorations where margins extend toofar subgingivally to allow isolation for bonding, or

over metal posts and implant abutments. We canalso fabricate all-ceramic bridges in the anterior andposterior with zirconia. I find that the combinationof Norataki’s pressable ceramic over a zirconia coreproduces exceptionally nice esthetic results thatrival what we can achieve with etched and bondedrestorations. In many cases, we are still using con-servatively prepared, adhesively placed veneers inthe anterior, then preparing more aggressively, andcementing zirconia-based, pressed ceramic restora-tions in the posterior to finish the case.

Mr. Russell: Dental restorations have been con-structed of different materials over the years.Porcelain-fused-to-metal (PFM) restorations havedominated this field for a long time as the mainstayfor clinicians. Over the last relatively few years, wehave seen all-ceramic systems appear on the market,consisting mainly of lithium disilicate or alumina-based–type systems. Zirconia-based restorations dif-fer from these materials in a number of ways. Theobvious difference zirconia has to a metal-basedrestoration is its color and translucency. The graycolor of the metal needs to be masked with a layerof opaque, and there is no light transmissionthrough its core. These drawbacks are overcome byusing a zirconia-based structure where light is

Lab Dialogue

Ed McLaren, DDSDirector, Center for Esthetic

Dentistry and School for Esthetic Dental Design

School of DentistryUniversity of California at

Los AngelesLos Angeles, California

Matt RobertsPrivate PracticeIdaho Falls, Idaho

IntroductionNext to the dentist-patient relation-

ship, the collaboration between dentistsand laboratory technicians is perhaps themost important ingredient for clinical andesthetic success in restorative cases. To-day, existing restorative products improveand new ones arrive on the market at sucha fast pace that it can be difficult to keepabreast of the latest advances. The ques-tions and answers that appear here are asampling of the most frequently asked-about issues and concerns that confrontboth dentists and technicians as theytreatment plan, fabricate, and seat a suc-cessful restorative case. The panel in thisissue is comprised of two dentists and twotechnicians, all of whom are well respect-ed in their fields for their knowledge andexpertise in delivering functional, yet high-ly esthetic, restorations to their clients.

Bob Winter, DDS Associate Professor of

Clinical Dentistry–Primary Oral Health CareUniversity of Southern

CaliforniaLos Angeles, California

Gordon Russell, RDTOwner, Next Level

Dental DesignHuntington Beach,California

10

allowed to pass through the framework to illuminatethe underlying tissue, and the inherently whitematerial can be colored to match the desired shadeof the surrounding teeth. The difference to the cur-rent all-ceramic systems is mainly an advantage instrength, where zirconia-based systems can be indi-cated for restoring missing posterior teeth withcrowns and bridges on a more routine basis.

Dr. Winter: Lava™a zirconia from 3M ESPE is sig-nificantly different from traditional all-ceramicmaterials because of its superior strength, and thefact that the zirconia substructure is available in 8shades to give more flexibility in achieving thedesired esthetic outcome. In addition, the manufac-turing process of the framework gives the technicianthe ability to design a framework that adequatelysupports the veneer ceramic, eliminating areas ofexcessive thickness of veneer material. This, in turn,decreases the risk of the veneer ceramic fracturing.

QWhy would I choose to use zirconia vs PFM?

ADr. McLaren: (1) Patient preference for metal-free; (2) I can use the same veneering porce-

lain for crowns, bridges, veneers, and glass ceramics;and (3) zirconia is more translucent than metal.

Mr. Roberts: Zirconia allows more light trans-mission than PFM. This, in turn, makes it easier forme to achieve natural-appearing restorations.Also, some patients are very nervous about puttingmetal in their mouth.

Mr. Russell: I would choose to use zirconia overPFM in situations where my client desired an all-ceramic restoration that didn’t contain metal butwhere strength in the posterior region was critical.I would also use it for esthetic cases where thetranslucency of zirconia would be to my advantage.An example today would be when restoring a full-mouth reconstruction, where in the past using dif-ferent types of materials in different locationscould have visible disharmony to the patient.

Dr. Winter: A zirconia restoration would beselected vs a PFM when there is a need to avoidmetals, such as in the case of allergies, and in theesthetic zone to achieve a more ideal result.

QWhat type of cements should I use forthe newer zirconia core-strengthened

materials?

ADr. McLaren: Low-solubility cements, ie, resincements or resin-reinforced glass ionomers.

Mr. Russell: A variety of different materials maybe used; however, studies have shown that the bestresults can be obtained with a self-curing resin-modified glass ionomer cement, especially if theframework was pretreated with Rocatec™,a.

Dr. Winter: Restorations fabricated with zirco-nia cores can be conventionally cemented withmaterials such as glass ionomer or resin-modifiedglass ionomer cements. To achieve the best bondstrength, surface-treat the zirconia with theRocatec System, and then use the RelyX™ UnicemSelf-adhesive Resin Cementa.

QWhat type of cement should I use with aporcelain veneer?

ADr. McLaren: A light-cure resin cement thathas minimal to no color shift on polymeriza-

tion.Mr. Roberts: Porcelain veneers are dependent

on the bond to underlying dentin and enamel fortheir survival. I have seen a 7-year, 97.5% successrate of several thousand restorations in one practiceand 100% failure rate of 135 restorations in anoth-er practice during the same time period. Therestorations were fabricated from the same ceramic,by the same lab (me); the only difference was thematerials and techniques used for placement. Mypersonal preferences are for fourth-generationdentin adhesives used with a total-etch technique,ie, ALL-BOND®2b and the two-part OptiBond®,c

system. I feel that which luting resin is used is lesscritical than the dentin adhesive, but my clientshave good luck with Variolink® IId. Finally, I wouldstress that I am a ceramist, not a dentist, and there-fore an armchair quarterback on this one. If youhave a system that has given you a high success rateand low sensitivity and microleakage, be very reluc-tant to change to anything new.

Mr. Russell: Choosing a cement for a veneermay be based on a variety of factors, such as thecolor of the substrate, the ability to alter the shadefor slight color modifications, the ability to bond todentin, ease of use and cleanup, and sensitivity tothe patient. The clients I work with usually havemore than one type of veneer cement and use themfor different situations, some brands being RelyXand Panavia®,e.

Dr. Winter: Porcelain veneer restorationsshould be bonded with resin cements.


bBISCO, Inc, Schaumburg, IL 60193; 800-247-3368cKerr Corporation, Orange, CA 92867; 800-537-7123dIvoclar Vivadent®, lnc, Amherst, NY 14228; 800-533-6825eKuraray Dental, New York, NY 10022; 800-879-1676a3M ESPE, St. Paul, MN 55144; 800-216-9502

QI’m having trouble with tight contacts onmy crowns. Could this be related to my

provisional material?

ADr. McLaren: Absolutely. A material thatwears easily or leaves open contacts because of

shrinkage on polymerization can precipitate toothmigration during the provisional phase.

Mr. Roberts: This may be less of a material issueand more of a technique issue. Whichever provi-sional material you use, make sure that contacts areproperly adjusted to prevent tooth movement.Open contacts on provisionals may allow shiftingto close the space; therefore, the contacts on therestorations will be tight. It may also be possiblethat more care needs to be taken by your techni-cian. Fitting to a solid model rather than a pinnedmodel will greatly reduce contact adjustment.

Mr. Russell: The problem of tight contactswhen fitting crowns can be caused by a number ofproblems, one of them being ill-fitting provision-als. Another cause could be the result of too muchexpansion in the materials used in the model work.What seems to give the most consistent results iswhen the impression material used by the dentistand the stone used by the laboratory are matched.The resulting fit is evaluated by the dentist, andadjustments are made by the lab accordingly forfuture cases. This setup can then be suggested toother clients when issues of fit are encountered.

Dr. Winter: If a dentist is having a problem withtight contacts when trying in a restoration, it ispossible that the provisional restoration was fabri-cated with too light of a contact, and the tooth hasmoved slightly. The material used to make the pro-visional should not influence the interproximalcontact, unless it is a long-term provisional. In thatcase, the wear characteristics of the material maybe a factor.

QDo you feel that a good impression isbased more on a good technique or a

good material?

ADr. McLaren: 80% technique.Mr. Roberts: Good technique!

Mr. Russell: I feel that a good impression ismore related to good technique rather than thematerial, because different dentists using the samematerial can achieve quite different results. Ease ofuse of the material may contribute to this, as well asgood technique in following the manufacturer’sdirections.

Dr. Winter: A good impression is the result ofboth. Adequate retraction of the gingival tissue isnecessary to reveal the tooth structure apical to thepreparation finish line, and there must be no conta-mination of the surface of the tooth with eitherdebris or moisture. The impression material must beinjected into this area without trapping bubbles.Material must flow adequately, be tear resistant,avoid deformation, and be dimensionally stable tocreate a good impression.

QWhat is the most common defect yousee in the impressions you receive?

What do you recommend to your clients toprevent these defects?

ADr. McLaren: Inadequate impressioning of mar-ginal detail is the most common defect. I would

recommend using the double-cord technique with atraumatic preparation techniques.

Mr. Roberts: Lack of marginal detail because ofsulcular fluid or hemorrhage is probably the mostcommon problem. This situation can be improvedby avoiding subgingival placements whenever pos-sible as well as being careful with the gingival tis-sues. The less bleeding that you cause duringpreparation, the less you have to control duringimpression taking.

Mr. Russell: The most common defect I see inimpressions is lack of sufficient retraction on thepreparations. When the impression captures theinformation below the margin, the technician isable to fabricate a restoration that has a smoothemergence in the transition from the tooth struc-ture to the crown structure. Good cord techniqueand control of oral fluids in the sulcus can improvethis situation greatly as well as by using a morehydrophilic impression material.

Dr. Winter: When I have the opportunity toevaluate impressions in the laboratory or whenteaching courses, the two most common defects inimpressions I observe are:

• material that has pulled away from the tooth,creating a positive deformity in the die. (The mostcommon cause of this is using materials that aretoo viscous, or a wet tooth surface.)

• defects in the material at the finish line of apreparation.

The goal of every impression is to capture toothstructure apical to the finish line. Keys for successare adequate retraction, clean and dry teeth, care-ful injection of the impression material, and theuse of impression materials that flow efficiently.


Scientifically SpeakingClinical and scientific expertise highlighted in the literature

Bonding Effectiveness of Adhesive LutingAgents to Enamel/DentinPublished by: K. Hikita,1 J. DeMunck,1 T. Ishijima,2

T. Maida,2 P. Lambrechts,2 B. Van Meerbeek1

1Catholic University of Leuven, Sapporo, Japan; 2Health Sciences University of Hokkaido, Sapporo, JapanPublished at: J Dent Res. 2004;83(spec iss A).Abstract 3175. Available at: http://iadr.confex.com/iadr/2004Hawaii/techprogram/abstract_39248.htm.Accessed January 7, 2005.Full abstract: 3M ESPE Espertise Scientific Facts,March 2004Aim of the Study: Microtensile bond strength methodwas used to examine adhesion of 5 luting cements,including RelyX™ Unicem Cement, to human teeth.Results: All cements showed equally good adhesion todentin (see note for Variolink™ II). The luting materialswith multistep pretreatment showed higher adhesionvalues to enamel.

Note by author of study: When bonded to dentin, Variolink II revealed anexceptionally high pretest failure rate and low adhesion to dentin. This wasmost likely caused by not having cured the adhesive separately and insuffi-cient light-curing of the cement.

Bond Strength of a Self-adhesive Universal ResinCement to Lava™ ZirconiaAfter Two SurfaceTreatmentsPublished by: D. Bulot, A.Sadan, J.O. Burgess, M.B.Blatz, Louisiana State UniversityHealth Sciences Center Schoolof Dentistry, New Orleans,Louisiana Published at: J Dent Res.2003;82(spec iss A). Abstract589. Available at: http://iadr.confex.com/iadr/2003SanAnton/techprogram/abstract_25944.htm.Accessed January 7, 2005.Full abstract: 3M ESPEEspertise Scientific Facts,March 2004Aim of the Study: To evaluatethe shear-bond strength of aself-adhesive universal cement(RelyX™ Unicem) to Lava™ zirco-nium oxide compared to 3common cement systems afterpretreatment of air-particleabrasion or tribochemical sur-face treatment with theRocatec™ System. Shear-bondstrengths were measured after72-hour water storage.Results: RelyX Unicem Cementrevealed bond strengths com-parable to or better than theother bonding systems. Surfacetreatment with the RocatecSystem significantly improvedbond strength for all bondingsystems.

A Prospective Study on the Long-termBehavior of Zirconia-based Bridges (Lava™):Results After 3 Years in ServicePublished by: P. Pospiech, F. Nothdurft, Department ofProsthetic Dentistry and Dental Materials Science,Saarland University, Homburg, GermanyPublished at: CED/NOF/ID Joint Meeting. Istanbul,Turkey; August 2004. Abstract 230.Full abstract: 3M ESPE Espertise Scientific Facts,March 2004Aim of the Study: To evaluate the clinical performanceof posterior Lava™ bridges from 3M™ ESPE™ fabricatedout of zirconium oxide and veneered with Lava Ceram.Results: No total failures, allergenic reactions, or nega-tive influences on the marginal gingiva could beobserved. A very good clinical performance of Lavaposterior bridges can be concluded after up to 3 years.


For complete information on 3M ESPE clinical and scientific marketing results, visit www.3MESPE.com/synergy.

Flow Properties of Light-bodiedImpression Materials DuringWorking TimePublished by: B. Richter, T. Klettke, B. Kuppermann, C. Führer, 3M ESPE AG,Seefeld, Germany Published at: CED/NOF/ID Joint Meeting.Istanbul, Turkey; August 2004. Abstract142.Full abstract: 3M ESPE EspertiseScientific Facts, March 2005Aim of the Study: To measure the flowproperties of light-bodied impressionmaterials under low pressure, during theworking time given by the manufacturer,using the Shark Fin test method.Results: Impregum™ Soft Quick StepLight Body and Impregum™ Soft LightBody Polyether impression materialsshowed superior flow properties, support-ing a high clinical reliability during thewhole working time.

Hydrophilicity of Precision ImpressionMaterials During Working TimePublished by: T. Klettke, B. Kuppermann, C. Führer, B. Richter, 3M ESPE AG, Seefeld, Germany Published at: CED/NOF/ID Joint Meeting. Istanbul, Turkey; August 2004. Abstract 141.Full abstract: 3M ESPE Espertise Scientific Facts,March 2005Aim of the Study: To investigate the hydrophilicityof unset light-bodied precision impression materialsdelivered from a hand dispenser; and to provide a method for determining the initial hydrophilicity of these materials using commercially availableequipment.Results: Impregum™ Soft Quick Step Light Body andImpregum™ Soft Light Body Polyether impressionmaterials were significantly more hydrophilic in theunset stage than the other vinyl polysiloxane materi-als tested. The measuring method used is a veryuseful and convenient tool to determine the contactangles of impression materials in the unset stage.


in dentistry

• Continuing Education articles

• Research on new materials

• Advances in clinical techniques

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The alliance between thedentist and lab technicianSynergy

Wesley J. Urich, DDSPrivate PracticePlymouth, Minnesota

Today, esthetic restorative treatments arecommon procedures. In many cases, toachieve the most optimal esthetic and

functional results, a multidisciplinary approach todiagnosis and treatment planning is necessary.1,2

This is particularly true when the clinician is facedwith determining whether or not to pursue ortho-dontic treatment before restorative procedures, orperforming “instant” orthodontics, ie, potentiallyoverreducing the teeth to correct the alignment inporcelain.

However, parafunctional habits that result inanterior incisal wear can leave the clinician with

some difficult restorative choices. Collaborationamong disciplines and thorough diagnostic exami-nations are paramount in determining the mostappropriate restorative materials for a given case,such as feldspathic vs pressed-ceramic veneers orzirconium-based vs glass-ceramic–based crowns.

Through the examination and collaborationprocess, the comprehensive occlusal aspects ofrestorative cases can be identified and addressed.2,3

For example, when a patient presents with specificwear facets, whether they are in the posterior oranterior region, there is usually an occlusal dis-crepancy.

With the numerous ceramic systems availabletoday, it is essential for the clinician to understandthe restorative protocols that will contribute to along-term, stable, and esthetic result. This articledescribes a case in which the patient presented witha fractured all-ceramic restoration on a maxillarycentral incisor, severe mandibular incisal wear, andparafunctional and orthodontic concerns. A conser-vative, multidisciplinary approach was taken toachieve optimal functional and esthetic results, inwhich a combination of Lava™ Crowns and Bridgesa

full-coverage crown restorations and feldspathicporcelain veneers was used.

Case PresentationA 43-year-old man presented with previous

porcelain-fused-to-metal (PFM) crown restorations

A Multidisciplinary Approach toReplacing Fractured Porcelain andCorrecting Worn Dentition WithZirconia All-ceramic Crowns andFeldspathic Veneers

AbstractEsthetic restorative treatments are now

common procedures in most dental offices.Often, a multidisciplinary approach to diagno-sis and treatment planning is necessary toachieve the most optimal esthetic and func-tional results. Parafunctional habits thatresult in anterior incisal wear can presentclinicians with some difficult restorative choic-es. With numerous ceramic systems availabletoday, it is essential to understand the restora-tive protocols that will contribute to a long-term, stable, and esthetic result. In the fol-lowing case presentation, the patient exhibiteda fractured all-ceramic restoration on a maxil-lary central incisor, severe mandibular incisalwear, and parafunctional and orthodonticconcerns. This article describes the conserva-tive, multidisciplinary approach taken toachieve optimal functional and esthetic resultsusing a combination of Lava™ Crowns andBridges full-coverage crown restorations andfeldspathic porcelain veneers.


a3M ESPE, St. Paul, MN 55144; 800-216-9502

that had been in place for 12years on teeth Nos. 8 and 9(Figure 1). As a result of para-functional habits and the PFMrestorations—which had sincebeen removed and replaced 3years before he presented to thisauthor—he exhibited extremewear on his mandibular incisors,resulting in exposed dentin(Figures 2 and 3). He had under-gone some orthodontic treat-ment in which the mandibularincisors were brought into occlu-sion with the existing PFMcrowns. The PFM crowns even-tually were replaced with all-ceramic crown restorations.However, the all-ceramic resto-ration on tooth No. 8 exhibiteda vertical fracture line on thebuccolingual aspects (Figure 4),necessitating its replacement.The patient demonstrated nooral pathologies. He did haveoccasional sensitivity on teethNos. 23 and 24 that he describedas “internal” sensitivity. Beforeseeing this clinician, the patientattempted at-home tray whiten-ing that resulted in severe sensi-tivity, so the patient stoppedbleaching. He wanted to replacethe maxillary crowns andexplore his options for replacingthe worn enamel on the man-dibular incisors.

Diagnostic Phase andTreatment Planning

A thorough diagnostic exam-ination was performed thatincluded centric relation (CR)

bite records, facebow registra-tion, and mounted study mod-els.2,3 It was the author’s opinionthat the masticatory musclesshould be “deprogrammed” andthe mandible eased into CRusing the bilateral manipulationtechnique, as described byDawson.4 The deprogrammingwas accomplished in approxi-mately 5 to 10 minutes using the(E) Tab System developed byEubank.5 A small maxillaryanterior jig of Filtek™ Supremea

restorative was fabricated tocover teeth Nos. 8 and 9 and thepatient was guided to a closedrelaxed contact with the jig. ACR position was reproducedusing bilateral manipulation(without the jig in place), and itwas observed that there was aslight discrepancy of ~1 mmbetween the CR position andthe intercuspal position (IP),with an initial left molar inter-ference and a protrusive slidewhen the patient was asked to“squeeze” his bite together.Placing the jig back on teethNos. 8 and 9, the CR positionwas then recorded by a contactmarking on the jig withAccuFilm® IIb.

The thickness of the jig wassuch that the only contact wason the jig, with adequate spacingbetween the remaining teeth fora thin layer of bite registrationmaterial. Imprint™ Bitea vinylpolysiloxane registration materi-

al was used to cover the bitingsurfaces of the maxillary arch,including the jig. The patientwas eased back into the CR posi-tion using bilateral manipula-tion, with contact on the jig andthe registration material fillingin the spaces. An accurate biterecord was verified with a small“burn through” of registrationmaterial on the jig at the pointof the contact marking.

A facebow record was takenwith an ARCUS facebowc, andthe study models were mountedon a PROTAR semi-adjustablearticulatorc using the CR biterecord. This revealed interfer-ence on teeth Nos. 15 and 18that created a slight protrusiveslide—slightly under 1 mm—into IP, thus verifying what theauthor had observed in themouth.

After analyzing the mountedstudy models, it was obvious tothe author that the space avail-able to cover teeth Nos. 22through 26 with porcelainveneers was very limited, andthe buccal version of tooth No.24 created even more of a prob-lem. The following options werediscussed with the patient: (1)instant orthodontics, whichwould involve aggressivelyreducing tooth No. 24 andnecessitating endodontic thera-py or (2) a removable spring-aligner orthodontic appliance,which would align tooth No. 24

Figure 1—Preoperative view of the patient’ssmile.

Figures 2 and 3—Preoperative facial views of the patient with the preexisting crowns on teethNos. 8 and 9. Mandibular incisal wear was the result of preorthodontic bruxism.

cKaVo America Corporation, Lake Zurich, IL 60047;800-323-8029


bParkell, Inc, Farmingdale, NY 11735; 800-243-7446

with teeth Nos. 22 through 27.With either option, CR mount-ed and equilibrated modelswould then need to be done todetermine if there was enoughroom to place veneers withouthaving to orthodontically lin-gualize teeth Nos. 22 through27. The patient chose the sec-ond option.

The removable orthodonticappliance was constructed andplaced in the patient’s mouth,ultimately repositioning thetooth lingually in about 5 weeks(Figures 5 and 6). Once thetooth was in the proper position,the appliance was used as aretainer to hold the tooth inplace. Given the patient’s desirefor a more natural-looking andesthetic appearance of his ante-rior dentition and the occlusalissues in question, further col-laborative and diagnostic workwas required to determine if thepatient could be restored withall-ceramic restorations withoutfirst undergoing additional or-thodontic treatment. A newlower impression was taken withPosition™ Penta™ Quicka materi-al, and the new model wasmounted to the existing mount-ed upper model with the CRbite record. The models wereequilibrated on the articulatorto eliminate the small protrusiveslide. The lower anteriors on themodel were prepared, and it wasdetermined by the author thatthe patient could be restoredinto proper occlusal function

and esthetics by treating themandibular dentition with feld-spathic veneers. This wouldinvolve less tooth reductionthan pressed-ceramic veneers.The prepared teeth were waxedto ideal with a Master Diag-nostic Model®,d. It was then dis-cussed with the patient that hisdesired results to replace theworn enamel with natural func-tion and esthetics could beachieved without further ortho-dontic treatment.

Material SelectionBecause they would allow

much more conservative prepara-tion designs than those requiredfor pressed-ceramic veneers,feldspathic veneers were chosenfor teeth Nos. 22 through 27. Forthe patient’s maxillary crowns,Lava restorations were chosen.

The Lava Crowns and BridgesSystem is an innovative comput-er-aided design/computer-aidedmanufacturing (CAD/CAM)technology for the fabrication ofall-ceramic crowns and bridgeswith a zirconium oxide base. Thismaterial was selected for the max-illary full-coverage crown restora-tions on teeth Nos. 8 and 9 basedon its strength, durability, andesthetics.6-8

Preparations for these res-torations allow the removal ofless tooth structure—1.5 mm to2 mm of incisal reduction is allthat is required, in addition to

1 mm to 1.5 mm of buccolingualreduction. Chamfer margins andround internal line angles alsoare required.

Thin and translucent col-orable frameworks ensure a nat-ural and vital appearance. How-ever, it is the author’s opinionthat reduction closer to 1.5 mmwill ensure the masking out ofany potential opacity from thezirconium core. These frame-works then can be veneeredwith Lava™ Cerama, a medium-fusing porcelain with thermalexpansion matched to the Lavaframework. Other veneeringporcelains compatible with Lavaframeworks also are available.After discussion with the ce-ramist, Vita® VM9e zirconiumveneering porcelain was used toachieve the best esthetic matchwith the Vita® Omega 900e low-fusing porcelain that was to beused for the laminates. It hasbeen this author’s experiencethat Lava crowns and bridgesprovide some of the mostdurable and esthetic all-ceramicrestorations available today.Specifically, Lava restorationsdemonstrate excellent estheticsand translucency, in addition tosuperior strength as a result ofzirconia’s high fracture resis-tance.

Preparation ProtocolThe patient was asked not to

drink any caffeine because of the

Figure 4—Note the vertical fracture line on thebuccolingual aspects of the crown restorationon tooth No. 8.

Figures 5 and 6—The lingual repositioning of tooth No. 25 was accomplished in 5 weeks withinterproximal discing and the placement of a removable orthodontic appliance.

dValley Dental Arts, Stillwater, MN 55082; 800-328-9157

eVita Zahnfabrik, Germany, distributed in US byVident™, Brea, CA 92621; 800-828-3839


potential for unwanted musclefunction the day of the prepara-tion appointment, because theocclusal equilibration wouldprecede the tooth preparations.With no anesthesia, the (E) TabSystem was used for this proce-dure with the placement of avery thin composite jig on themaxillary centrals, similar to thetechnique used for the CR biterecord. Bilateral manipulation

of the mandible produced a con-tact marking on the jig. Reduc-tion of the marking on the jigproduced the first interferencewith teeth Nos. 15 and 18.Minimal adjustments, alternat-ing between interferences onthe teeth and the jig, were nec-essary to eliminate the smallprotrusive slide. The end resultwas no discrepancy between theCR position and the IP.

After removing the maxillaryanterior all-ceramic crown res-torations, it was noted that theprevious clinician had overre-duced the preparations for thosecrowns. In particular, they weremore subgingival than desiredand there was significantly moreincisal reduction than necessary.However, these preparationswere successfully modified toenable predictable results with

Figure 7—Previous aggressive crown prepa-rations were modified for the anticipated Lavacrown restorations.

Figure 8—Completed preparations on teethNos. 22 through 27 for the placement of feld-spathic porcelain veneers.

Figure 9—The maxillary polyether impressionon the left and the mandibular vinyl polysilox-ane impression on the right accurately cap-tured the preparation designs.

Figure 10—A printout of the ShadeScan Plus was used for shade mapping the final porcelain restorations.


Figure 16—Initial placement of the definitiveveneer restorations on teeth Nos. 24 and 25with the translucent shade of RelyX VeneerCement.

the anticipated Lava restora-tions (Figure 7). In these situa-tions, the digital wax-knife fea-ture of the Lava CAD/CAMsystem allows for thicker yet stilltranslucent copings to preventexcessive thickness in unsupport-ed porcelain veneering ceramic.

In the mandibular dentition,although still prepared moreconservatively than what wouldbe required for pressed-ceramicrestorations, the incisal half ofthe teeth was reduced sufficient-ly (Figure 8) to provide the lab-oratory technician with ampleroom to create natural-lookingincisal edges for the proposedveneer restorations (flat incisaledges resulted from the patient’sprevious wear). The NixonVeneer II Kitf was used for thepreparations, with 0.5-mm cer-vical depth cuts and 1-mmincisal depth cuts being placed.The 850-014 diamond was thenused to “blend” the depth cutsand place the margins.9 Al-though there were visible pulpchambers on the teeth, the

preparations were done withoutanesthesia and there was virtual-ly no discomfort because of thereceded pulp tissue.

Impression Making andTemporization

Because the original prepa-rations were more subgingivalthan desired, a polyether im-pression material (Impergum™

Penta™ Soft Quick Stepa) wasused to make impressions of themaxillary dentition. This quick-setting impression material wasthe foundation for the zirconia-based Lava crown restorations.

Because of the spacing thepatient demonstrated betweenhis mandibular dentition as aresult of the previous orthodontictreatment (ie, black triangles andtissue embrasures), a vinyl poly-siloxane impression material witha demonstrated good tear factorwas used (Imprint™ II Garant™,a).This accurately captured thepreparation design and theembrasure areas without tearingon removal from the mouth(Figure 9). In the author’s experi-ence, it is important not to use air

spray to adapt the wash material,because it can “lock in” more intothe embrasure areas and increasethe chance for tearing onremoval. The patient then wassent to the laboratory for a com-puterized shade match using theShadeScan™ Plusg (Figure 10).

Temporization was completedusing the “shrink-to-fit” tech-nique developed by Hornbrook.10

The teeth were spot-etched with a35% phosphoric acid gel (Figure11), after which an adhesivebonding agent (Adper™ SingleBond Plusa) was placed on thepreparations and cured (Figure12). Shade A2 of Protemp™ 3Garant™,a temporization materialwas loaded into a vinyl matrix cre-ated from the Master DiagnosticModel and placed in the patient’smouth (Figure 13). Note the min-imal amount of flash of materialafter the matrix was removed(Figure 14). Minor trimmingalong the gingival margins andcontouring was completed withan ET9f carbide bur, resulting invery little tissue irritation.

Figure 13—Shade A2 of Protemp 3 Garantmaterial was placed in a putty matrix.

Figure 14—View of the provisional veneerson teeth Nos. 22 through 27 immediately afterremoval of the putty matrix.

Figure 15—The completed Protemp 3 Garanttemporization material provisional restorationswith Sinfony honey yellow cervical staining.

Figure 11—The preparations were spot-etched with a 35% phosphoric acid gel.

Figure 12—Placement of Adper Single BondPlus adhesive.

fBrasseler USA®, Savannah, GA 31419; 800-841-4522

gCynovad, Saint-Laurent, Quebec H4S 1V9; 866-CYNOVAD


The maxillary provisionalrestorations were created in asimilar manner, but they wereseated with a cement indicatedfor stronger, longer-term provi-sional restorations (Durelon™,a).This was necessary because ofthe shortness of the existingpreparations and to reduce anylikelihood of the temporariesdislodging.

Both the maxillary andmandibular provisional restora-tions were stained in the cervi-cal area with Sinfony™ Magichoney yellowa to impart a natur-al look (Figure 15).

CementationThe author’s technique for

seating veneers is done in pairs,starting with the central incisorsand working posteriorly.11 At thecementation appointment, theprovisional restorations wereeasily removed, a rubber damwas placed to isolate themandibular anteriors, and thepreparations were cleaned withConsepsis® Scrubh and a prophycup. The veneers were first triedin individually to check themargins and then all at oncewith RelyX™ Translucent Try-inPastea, which is water soluble, toverify the shade and check thecontacts. The translucent shadewas chosen because there was nocolor shift from tooth structureto veneer, and the contact-lenseffect created by the cervicalmargins of the veneers allowedfor a seamless transition withthe tooth structure. The authorprefers to use phosphoric acidfor 5 seconds on the etched sur-face of the veneer and rinse withwater before placing the RelyX™

Ceramic Primera. Two coats ofAdper Single Bond Plus adhe-sive were applied after 1 minuteto the primed surface, thinned

out but not polymerized, and the veneers were placed in a ResinKeeper Mixing andStorage Palettei. The teeth wereetched with Scotchbond™ 35%phosphoric etchanta for 10 sec-onds, rinsed, and lightly dried.Two coats of Adper™ SingleBond Plus adhesive were appliedfor 15 seconds, thinned out, andpolymerized for 10 seconds withthe Elipar™ FreeLight 2a.

RelyX™ Translucent VeneerCementa was placed inside theveneers, and the veneers wereseated onto the preparations(Figure 16). The “tack andwave” technique with RelyXVeneer Cement—introduced byHornbrook12—was used, in whicha 1-second tack and a 1-secondwave along the margins are firstcompleted with the EliparFreeLight 2. Excess cement waseasily removed from the marginswith an interproximal carver,flossed, and finely cleaned with aBard Parker No. 12j. Every sur-

face was then polymerized for 20seconds with the Elipar FreeLight2. In the author’s experience, thistechnique leaves very minimal, ifany, excess cement on the mar-gins. However, one must be care-ful not to overpolymerize thetack stage, or cleanup becomesmore time consuming. Minimalpolishing was done with Sof-Lex™

Extra Thin, Superfine Finishingand Polishing Discsa. The sameprotocol was used for the remain-ing veneer restorations.

Zirconia-based restorationscan be cemented with tradition-al glass ionomers, resin-modifiedglass ionomers, luting cements,or a self-etching adhesive resincement.13 The author chose touse RelyX™ Unicem Self-Adhe-sive Universal Resin Cementa

translucent shade to seat theLava crowns on teeth Nos. 8 and9 because of the shortness of thepreparations. The crowns weretried in to verify interproximaland centric contacts and excel-lent marginal adaptation. Noadjustments were necessary. Thetooth preparations were cleaned

Figures 17 and 18—Completed treatment with Lava crowns on teeth Nos. 8 and 9 and feldspathicporcelain veneers on teeth Nos. 22 through 27. Note the natural incisal-edge contours of themandibular incisors. Compare to Figures 2 and 3.

Figure 19—Retracted 1:1 view of Lavacrowns on teeth Nos. 8 and 9. Note the natur-al appearance of the surface texture andincisal characterization.

Figure 20—Postoperative view of the pa-tient’s smile.

hUltradent Products, Inc, South Jordan, UT 84095;800-552-5512

iCosmedent, Inc, Chicago, IL 60611; 800-621-6729jBecton Dickinson and Company, Franklin Lakes,NJ 07417; 888-237-2762


with Consepsis Scrub and a prophy cup, rinsed, and lightlydried. After the crowns werecleaned and dried, a RelyX™

Unicem Cement Maxicapa cap-sule was triturated, the materialwas placed inside the crowns,and both crowns were simulta-neously seated in place. Thecement could be either light-cured or chemical-cured. Theauthor’s technique of choice wasto “tack and wave” the margins,clean the excess, and polymer-ize, similar to the technique usedfor the veneer cementation.Additionally, use of this self-adhesive resin cement alsohelped to eliminate some of thetechnique-sensitive, unpredict-able, and time-consuming stepsassociated with other traditionalresin bonding cements.13 Noanesthetic was used duringcementation, and the patientexperienced no sensitivity.

The author would normallyrecommend a mandibular hard/soft acrylic splint with a verysmooth occlusal surface to wearat night; however, the patientcurrently wore a PM Positioner®

snoring devicek at night. So, thethermoplastic material of thedevice was softened in verywarm water and adapted to fitthe new restorations.

ConclusionWith the numerous ceramic

systems available today, it isessential for clinicians to collab-orate with members of other dis-ciplines, as well as their labora-tory technicians, and implementthe restorative and diagnosticprotocols that will ultimately

enable them to deliver long-term, stable, and esthetic results.In this case, a multidisciplinaryapproach to diagnosis and treat-ment planning, combined withthe use of a durable and estheticall-ceramic material, contrib-uted to natural-looking andfunctionally sound restorations(Figures 17 through 20). Giventhe esthetics that could beachieved, in addition to the easeof cementability and provenstrength, Lava restorations werethe logical choice based on all ofthe diagnostic and treatmentplanning information reviewedby the clinician and the techni-cian. Furthermore, with theocclusion issues addressed andcorrected, this material could beconfidently placed because thestrength of the Lava core willwithstand normal occlusalforces, which have now beenreestablished in the patient.

DisclosureThe author is a paid consul-

tant for 3M ESPE.

AcknowledgmentsThe author wishes to thank

Valley Dental Arts (Stillwater,Minnesota) and especially JennyWohlberg for the ceramic art-istry featured in this article.

References1. Alfe G. A multidisciplinary approach to

treatment. Contemporary Esthetics andRestorative Practice. March 2004;8:20-29.

2. Trinkner TF, Robinson M, Roberts M.Achieving esthetic goals while maintain-ing proper bite relationships throughouttreatment. Contemporary Esthetics andRestorative Practice. September 2003;7:38-50.

3. Wynne WP. Considerations for estab-lishing and maintaining proper occlu-sion in the aesthetic zone. Dent Today.2004;23:112-119.

4. Dawson PE. Evaluation, Diagnosis, andTreatment of Occlusal Problems. 1st ed. St.Louis, Mo: Mosby-Year Book; 1974:54-60.

5. Eubank J. The (E) Tab, The (E) Pontic andThe Eubank Bridge. American Academyof Cosmetic Dentistry, scientific session,April 30, 2004, Vancouver, BC.

6. Suttor D. Lava zirconia crowns andbridges. Int J Comput Dent. 2004;7:67-76.

7. Suttor D, Bunke K, Hoescheler S, et al.LAVA—the system for all-ceramic ZrO2

crown and bridge frameworks. Int J Comput Dent. 2001;4:195-206.

8. Kugel G, Perry RD, Aboushala A.Restoring anterior maxillary dentitionusing alumina- and zirconia-based CAD/CAM restorations. Compend Contin EducDent. 2003;24:569-580.

9. Nixon RL. Mandibular ceramic veneers:an examination of diverse cases. PractPeriodontics Aesthet Dent. May 1995;7:17-30.

10. Hornbrook DS. New Product Review.AACD Journal. Spring 1997;8-13.

11. Nixon RL, Weinstock A. An immediate-extraction anterior single-tooth replace-ment utilizing a fiber-reinforced dual-component bridge. Pract PeriodonticsAesthet Dent. 1998;10:17-28.

12. Hornbrook DS. Cementation of all-cera-mic veneers using the “tack and wave”technique. Contemporary Esthetics andRestorative Practice. April 2002;6:36-48.

13. Bulot D, Sadan A, Burgess JO, et al.Bond strengths of a self-adhesive univer-sal resin cement to Lava zirconia aftertwo surface treatments. Paper presentedat: Academy of Dental Materials AnnualMeeting; October 29, 2002; Honolulu,Hawaii.

Dr. Urich graduated from the University ofMinnesota School of Dentistry in 1983.He maintains a private practice in theMinneapolis area with a focus on compre-hensive esthetic, restorative, and implantdentistry. As an accredited member of theAmerican Academy of Cosmetic Dentistry(AACD), Dr. Urich also serves on theAmerican Board of Cosmetic Dentistry ofthe AACD and is an accreditation examin-er. He is a founding member and pastpresident of the Minnesota Academy ofCosmetic Dentistry. He has had the fortu-nate opportunity to share what he haslearned in a variety of lecture and hands-on venues. Dr. Urich has been recognizedby his peers as a top cosmetic and gener-al dentist in Minneapolis St. PaulMagazine. He can be reached [email protected].

kDental Services Group, Minneapolis, MN 55416;800-843-4110


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