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The use of CAD/CAM technology to fabricate a custom ceramic implant abutment: A clinical report Martinna de Mendonça e Bertolini, DDS, MSc, a Juan Kempen, b Eduardo José Veras Lourenço, DDS, MSc, PhD, c and Daniel de Moraes Telles, DDS, MSc, PhD d Piracicaba Dental School, State University of Campinas. Piracicaba, SP Brazil; State University of Rio de Janeiro. Maracanã, RJ Brazil Well-placed dental implants are a prerequisite of functional and esthetically successful dental implant–supported crowns. The presence of soft tissue is essential for excellent esthetics because the dental implant or titanium abutment may become visible if the soft-tissue contour is not acceptable. This clinical report describes the use of a custom ceramic implant abutment designed with computer-aided design and computer-aided manufacturing (CAD/CAM) technology by milling a zirconia framework that was cemented extraorally to a prefabricated titanium abutment with a reduced diameter. This ceramic abutment has the strength and precise fit of a titanium interface and also the esthetic advantages of shaded custom-milled zirconia, with no visible metal. (J Prosthet Dent 2014;111:362-366) Well-placed dental implants are a prerequisite of functional and es- thetically successful dental implant– supported restorations. In addition to sufficient bone volume, a precise emer- gence profile is important in obtaining a definitive restoration with a natural gingival silhouette. 1 However, a com- mon problem after dental implant sur- gery is the position of the buccal gingival margin and, sometimes, an insufficient papilla around the dental implant plat- form to hide the titanium abutment. 2 Prosthetic management can be based on different dental implant abutments, 3 for example, titanium abutments, which can cause grayness on periimplant soft tissue 4 and zirconia abutments, which are recommended for esthetic areas but which still require long-term evaluations for use in the posterior regions. 5,6 Therefore, when considering the advan- tages 5 and disadvantages 6 of these ap- proaches, 7 zirconia abutments with titanium inserts have been developed; however, they can show titanium. With this in mind, an alternative technique has been devised for esthetic areas under heavy occlusal loading. 8 The use of computer-aided design/ computer-aided manufacturing (CAD/ CAM) technology to produce zirconia frameworks, 9 including the creation of a combination implant crown, solves many different problems. 10-13 The alternative technique described in the present article used a zirconia framework cemented to a prefabricated titanium abutment to pro- vide good esthetics and avoid the pres- ence of zirconia at the abutment hexagon connection, which could lead to failure in the posterior areas. 14,15 This clinical report describes the successful use of a custom ceramic implant abutment designed with CAD/CAM technology. This custom abutment combined the strength and precise fit of a titanium implant abutment with the esthetic ad- vantages of shaded custom-milled zirco- nia with a feldspathic porcelain veneer. CLINICAL REPORT A 40-year-old woman received an implant (Full Osseotite Tapered Dental Implant; Biomet 3i) with a 5 8.5 mm and external hexagon connection at the maxillary right first molar region without immediate load. After 4 months, the dental implant was surgi- cally reexposed, and an interim resto- ration was attached. After healing, the dental implant platform was at the gingival level, with a lack of surrounding soft tissue (Fig. 1). This condition could have compromised the appearance of the definitive restoration by exposing the titanium abutment border. At that time, a ceramic abutment that could fit this dental implant was not available and because of heavy occlusal load, a new approach was adopted. 13 A customemilled zirconia frame- work (Lava Ceramic System; 3M ESPE) was designed and milled with CAD/CAM technology, veneered with feldspathic a Graduate student, Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas. b Dental Technician, Belo Horizonte, MG Brazil. c Associate Professor, Department of Prosthodontics, State University of Rio de Janeiro. d Associate Professor, Department of Prosthodontics, State University of Rio de Janeiro. The Journal of Prosthetic Dentistry Bertolini et al
description
CAD CAM dentistry
Transcript of CAD CAM 11
Thefabrabu
Martinna de Men
aGraduate student, Department of PbDental Technician, Belo Horizonte,cAssociate Professor, Department ofdAssociate Professor, Department of
The Journal of Prosthetic
use of CAD/CAM technology toicate a custom ceramic implanttment: A clinical report
donça e Bertolini, DDS, MSc,a Juan Kempen,b
Eduardo José Veras Lourenço, DDS, MSc, PhD,c andDaniel de Moraes Telles, DDS, MSc, PhDd
Piracicaba Dental School, State University of Campinas.Piracicaba, SP Brazil; State University of Rio de Janeiro.Maracanã, RJ Brazil
Well-placed dental implants are a prerequisite of functional and esthetically successful dental implant–supported crowns. Thepresence of soft tissue is essential for excellent esthetics because the dental implant or titanium abutment may become visibleif the soft-tissue contour is not acceptable. This clinical report describes the use of a custom ceramic implant abutmentdesigned with computer-aided design and computer-aided manufacturing (CAD/CAM) technology by milling a zirconiaframework that was cemented extraorally to a prefabricated titanium abutment with a reduced diameter. This ceramicabutment has the strength and precise fit of a titanium interface and also the esthetic advantages of shaded custom-milledzirconia, with no visible metal. (J Prosthet Dent 2014;111:362-366)
Well-placed dental implants area prerequisite of functional and es-thetically successful dental implant–supported restorations. In addition tosufficient bone volume, a precise emer-gence profile is important in obtaininga definitive restoration with a naturalgingival silhouette.1 However, a com-mon problem after dental implant sur-gery is the position of the buccal gingivalmargin and, sometimes, an insufficientpapilla around the dental implant plat-form to hide the titanium abutment.2
Prosthetic management can be basedon different dental implant abutments,3
for example, titanium abutments, whichcan cause grayness on periimplant softtissue4 and zirconia abutments, whichare recommended for esthetic areas butwhich still require long-term evaluationsfor use in the posterior regions.5,6
Therefore, when considering the advan-tages5 and disadvantages6 of these ap-proaches,7 zirconia abutments withtitanium inserts have been developed;
rosthodonMG BraziProsthodProsthod
Dentis
however, they can show titanium. Withthis in mind, an alternative techniquehas been devised for esthetic areas underheavy occlusal loading.8
The use of computer-aided design/computer-aided manufacturing (CAD/CAM) technology to produce zirconiaframeworks,9 including the creation of acombination implant crown, solvesmanydifferent problems.10-13 The alternativetechnique described in the present articleused a zirconia framework cemented to aprefabricated titanium abutment to pro-vide good esthetics and avoid the pres-ence of zirconia at the abutment hexagonconnection, which could lead to failure inthe posterior areas.14,15 This clinicalreport describes the successful use of acustom ceramic implant abutmentdesigned with CAD/CAM technology.This custom abutment combined thestrength and precise fit of a titaniumimplant abutment with the esthetic ad-vantages of shaded custom-milled zirco-nia with a feldspathic porcelain veneer.
tics and Periodontology, Piracicaba Dental Scl.ontics, State University of Rio de Janeiro.ontics, State University of Rio de Janeiro.
try
CLINICAL REPORT
A 40-year-old woman received animplant (Full Osseotite Tapered DentalImplant; Biomet 3i) with a 5 � 8.5 mmand external hexagon connection atthe maxillary right first molar regionwithout immediate load. After 4months, the dental implant was surgi-cally reexposed, and an interim resto-ration was attached. After healing, thedental implant platform was at thegingival level, with a lack of surroundingsoft tissue (Fig. 1). This condition couldhave compromised the appearance ofthe definitive restoration by exposingthe titanium abutment border. At thattime, a ceramic abutment that could fitthis dental implant was not availableand because of heavy occlusal load, anew approach was adopted.13
A customemilled zirconia frame-work (Lava Ceramic System; 3M ESPE)was designed andmilledwith CAD/CAMtechnology, veneered with feldspathic
hool, State University of Campinas.
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1 Buccal view of dental implant platform at soft-tissue level.
2 Selected 4.1-mm abutment placed onto 5.0-mm dentalimplant analog. Note extra space needed for this type ofabutment to create finish line for zirconia crown. Minimumwall thickness is 0.5 mm for posterior crowns and 0.3 mm foranterior crowns according to manufacturer.
3 Computer-assisted design image obtained by scanning4.1-mm abutment over 5.0-mm dental implant analog.
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porcelain (Lava Ceram Veneer Ceramic;3M ESPE), and then cemented to aprefabricated titanium abutment witha reduced diameter (Biomet 3i) to pro-vide a metal-free shoulder around thetitanium abutment. The close toleranceof the machined titanium interfaceprovided an accurate fitting surface withthe dental implant and titanium abut-ment, and the necessary metal-to-metalhexagon connection16; the use of zirco-nia enhanced the esthetics.
A 4.1-mm titanium abutment wasadapted to the external hexagon of a5.0-mm dental implant analog (Fig. 2)and scanned with the Lava CAD/CAMScan system (Lava Ceramic System; 3MESPE) to create a computer-assisteddesign image (Fig. 3). The custom zir-conia framework was then digitallydesigned with an anatomic shape and ashoulder placed around the abutmenthead, which hid the titanium (Fig. 4).After it was digitally designed, the zir-conia framework was milled and sin-tered according to the manufacturer’sinstructions17 and was veneered withfeldspathic porcelain for esthetics anddefinitive shape.18
The finished ceramic crown wascemented to the titanium abutmentafter airborne-particle abrasion withaluminum oxide �50 mm and 0.2MPa19 and cleaning with ethanol. Thetitanium abutment (Biomet 3i) wasscrewed on the implant analog on thecast, and the screw was coated withwax. Composite resin cement (RelyXUnicem; 3M ESPE) was used to cementthe surfaces of both devices, and eachside was prepolymerized with a lightunit for 20 seconds. The definitivepolymerization was done in a light unit(Visio Beta Vario - 1st program; 3MESPE) with a 15-minute light exposureunder vacuum. Excess cement wasremoved, and the interface between thedental implant and the titanium-zirconia abutment base was finishedwith a diamond impregnated polishingsystem (Dialite ZR Extra-Oral; BrasselerUSA) until a smooth surface was ach-ieved (Fig. 5).
The occlusion and esthetics ofthe custom 1-piece ceramic bonded to
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metal crown was evaluated intraorally(Fig. 6) and then a torque of 32 Ncmwas applied to the abutment screw
(Fig. 7). Subsequently, the screw accesschannel was filled20 and sealed with acomposite resin material (Tetric
6 Buccal view of crown with satisfactory esthetic andemergence profile without showing titanium abutment.
4 Computer-assisted design image of anatomic zirconiaframework designed by using computer software.
5 Cervical view of zirconia crown after feldspathic porcelainapplication for esthetic and definitive shape, followed bycementation on titanium abutment.
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EvoCeram; Ivoclar Vivadent), and a fineocclusal adjustment of the crown wasmade. A radiograph was made along
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the long axis of the dental implant toensure that the abutment wascompletely seated on the dental
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implant. After 5 years of follow-up, aradiograph revealed no clinical or bio-logic problems associated with theprosthetic treatment (Fig. 8).
DISCUSSION
The proposed custom ceramic im-plant abutment may be appropriate forpatients with gingival recession or thingingival tissue in esthetic areas, where aconventional titanium abutment couldcause grayness of the periimplant softtissues.4 In addition, it can be used forposterior areas where the abutmentshoulder could be visible, even underheavy occlusal load as in the clinicalreport presented here. Therefore, thiscustom ceramic implant abutment maybe an alternative to the use of a con-ventional metal ceramic crown cemen-ted on a titanium abutment or ceramicabutments.
This technique combines thestrength and precise fit of a titaniumdental implant-abutment interface withthe esthetics of shaded custom-milledzirconia, provides a custom anatomicemergence profile for the definitiveabutment, if necessary, and avoids theneed for waxing and burnout pro-cedures, thereby increasing the stan-dardization of definitive frameworks,once it is made digitally. The screw-retained crown, despite a visible screwaccess (sealed with composite resin),allows for removal if necessary. Extrao-ral cementation can be less critical andmore effective than the same proceduredone intraorally, once it is possible touse a light unit with vacuum for defin-itive polymerization. The screw-retainedceramic crown assures good retention,function, efficiency, and access to thescrew. Finally, the system is not limitedto a specific dental implant system. Insituations where no compatible abut-ments with diameters smaller than thedental implant platform are available,the abutment can be previously milledto create the necessary space with ashoulder for the zirconia framework.Some manufacturers are developingtitanium abutments with a basefor custom-made ceramic zirconia
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7 Occlusal view of crown before definitive screw accessclosure.
8 Follow-up. After 5 years no clinical or biologic problemwas observed.
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abutments and a plastic waxing sleevethat can be contoured with wax orcomposite resin and then scanned. Thissystem also has some disadvantages.When screw access to the implant is inan esthetic area, special managementmay be required. Further clinical studiesare required to prove the durability ofthis restorative approach over longerfollow-up periods, and in vitro tests areneeded to evaluate the mechanicalpropriety of these ceramic abutments.8
SUMMARY
This article demonstrates how CAD/CAM technology was used to create acustom ceramic dental implant abut-ment crown for a posterior but estheticregion when insufficient soft tissue
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made it necessary to hide the dentalimplant abutment border. This restor-ative system consisted of a custome
milled zirconia framework, which wascemented extraorally over a prefab-ricated titanium abutment with reduceddiameter and screwed in intraorally.This ceramic abutment has the strengthand precise fit of a titanium interfaceand also the esthetic advantages ofshaded custom-milled zirconia.
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Notewort
Clinically relevant fracture testing
Øilo M, Kvam K, Tibballs JE, Gjerdet NR
Dent Mater 2013;29:815-23
Objectives:Fracture strength measured in vitro indicaNevertheless, fractures are one of the majof all-ceramic crowns observed in clinicalpresent study was to develop and investig
Methods:30 crowns with alumina cores were maderandomly allocated to 3 tests groups (n¼subsequently fractured by occlusal loadinwith expanding cement. The crowns in grfractured by increasing the diameter of thfractographic methods and compared to
Results:The fracture modes of all the in vitro crowclosely matched to the clinical fractures. T
Conclusion:Laboratory tests that induce a distortioncan simulate clinical fractures of all-ceram
Copyright ª 2013 Academy of Dental M
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19. Ebert A, Hedderich J, Kern M. Retention ofzirconia ceramic copings bonded to titaniumabutments. Int J Oral Maxillofac Implants2007;22:921-7.
20. Moráguez OD, Belser UC. The use of poly-tetrafluoroethylene tape for the managementof screw access channels in implant-supported prostheses. J Prosthet Dent2010;103:189-91.
hy Abstracts of the Current Li
of all-ceramic crowns
tes that most all-ceramic crowns should bor clinical problems with all-ceramic restoruse differs from that found in conventionaate a method that simulates clinical fractu
to fit a cylindrical model with a molar-like10). The crowns in group 1 were cementeg without contact damage. The crowns inoup 3 were cemented on an abutment moe model in the bucco-lingual direction. Tha reference group of 10 crowns fractured
ns were similar to clinical fracture modes. These crowns also fractured at clinically re
of the abutment model during occlusal loic crowns.
aterials. Published by Elsevier Ltd. All right
try
Corresponding author:Dr Martinna de Mendonça e BertoliniPiracicaba Dental SchoolState University of CampinasPO Box 52 13414-903Piracicaba, SPBRAZILE-mail: [email protected]
Copyright ª 2014 by the Editorial Council forThe Journal of Prosthetic Dentistry.
terature
e able to withstand mastication forces.ations. Furthermore, the fracture model fracture strength tests. The aim of there behavior in vitro.
preparation design. These crowns wered to abutment models of epoxy andgroup 2 were fractured by cementationdel of epoxy split almost in two ande fractured crowns were analyzed byin clinical use.
he fracture modes in group 1 were mostlevant loads.
ading without occlusal contact damage
s reserved.
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