Digital Dentistry
`
`_
`
`__ _
`
`the target site, from which the techni(cid:173)
`cian is able to &bric:acc an accurate gyp(cid:173)
`sum positive duplic:acing the original
`inttao1'21 situation. The advent of high(cid:173)
`ly innov.ative and accur2tc imp~ion(cid:173)
`ing systems based on new ccchnologics
`has created a par.idigm shift in the con(cid:173)
`cept for impression making. These sys(cid:173)
`tems arc poised to revolutionize the way
`in which dental professionals already
`arc and will c.ontinuc making impres(cid:173)
`sions for indirect rcstor2tive dentistry.
`
`Dental Impressions Using
`3D Digital Scanners:
`Virtual Becomes Reality
`
`Nathan S. Birnbaum, 005; 1 and Heidi B. Aaronson, DMD 2
`
`Abstract the technologies that have made the use of three-dlmenslonal (3D)
`digital scanners an Integral part of many Industries for decades have been
`Improved and refined for application to dentistry. Since the Introduction of the
`first dental lmpressJonlng digital scanner In the 19805, development engineers
`at a number of companies have enhanced the technologies and aeated In(cid:173)
`office scanners that are Increasingly user-friendly and able to produce precisely
`fitting dental restorations. These systems are aipable of aipturlng 3D vlrtual
`Images of tooth preparations, from which restorations may be fabricated
`directly (le, CAD/CAM systems) or fabricated Indirectly (le, dedicated Impres(cid:173)
`sion scann Ing systems for the creation of accurate muter models). The use of
`these products is Ina-easing rapidly around the world and presents • paradigm
`shift In the way In which dental lmprmslons are made. Several of the leading
`3D dental digital scanning systems are presented and discussed In this artkle.
`
`FROM BITES TO
`BYTES: A BRIEF HISTORY
`OF IMPRESSIONING
`IN DENTISTRY
`Impression making for rcstorative dcn(cid:173)
`tiscry is a rclacivcly recent concept in
`the millennia-old history of restorative
`dentistry. The carliesc physical proof
`or record of prosthetic treatment to re(cid:173)
`place missing teeth goes back to Etrus(cid:173)
`can times, approximately 700 BC in
`which tcech were carved from ivory
`and bone and affixed to adjacent teeth
`with gold wires. le was not until 1856, when Or. Charles
`Stent perfected an impression material for use in the fabrica(cid:173)
`tion of the device that bears his name for the correction of
`oral deformities, that documentation exists of the use of an
`impression material other than beeswax or plaster of Paris,
`which had inhcrcnc problems, respectively, of distonion or
`difficulty of use, for crcacing an oral prosthesis. 1
`The first use of an clastomcric maccrial for capturing
`impressions of cooth preparations, as well as ocher oral and
`dental condicions, was not until 1937. when Scars intro(cid:173)
`duced agar as an impression material for crown prepara(cid:173)
`cions.2 In the mere 71 years chac elastic impression materials
`ha\'c been in we, numerous formulations ha,·e been devel(cid:173)
`oped, all of which ha\"c exhibicc:d panicular shoncomings
`
`THE CONCEPT OF IMPRESSION MAKING
`The most cricical seep in the process oHabricating precisely
`fining fixed or rcmov.ablc dcmal proschescs is the capture of
`an aooirace impression of prepared or unprepared teem, den(cid:173)
`cal implants, edentulous ridges, or innaoral landmarks or
`defects. Unless a wax or resin panern is made directly on cltc
`teech, on the edcmulous ridges, or in the defects, which is a
`time-consuming and generally impractical effort, the dentist
`or auxiliary muse achieve an exact duplication of the sice so
`thac a laboratory cechnician, usually at a remote location, can
`creace the rescoracion on a precise replica of chc cargc:c sicc:.
`Traditionally, the paradigm for transferring chc necruary
`information from the pacic:m's oral c:l\'ity to che cechnici:m's
`labor:uory bench has been ro obcain an accumc: nc:gach'c of
`
`1 Associate Clinical Professor, Department of Prosthodontics and Operative Dentistry, Tufts University School of Dental Medicine,
`Boston, Massachusetts; Private Practice, Wellesley, Massachusetts
`2Private Practice, Wellesley, Massachusetts
`
`0001
`
`Exhibit 1039 page 1 of 10
`DENTAL IMAGING
`
`

`

`Dig~tal Dentistry
`
`in the goal of obtaining precise reproduction of the oral
`structures.
`The reversible hydrocolloid agar and the irreversible hy(cid:173)
`drocolloid alginate exhibit poor dimensional stability be(cid:173)
`cause of the imbibition or loss of water, respectively, when
`sitting in wet or dry conditions, as well as in having low
`tear resistance. The Japanese embargo on the sale of agar to
`the United States during World War II spurred research
`into the development of alternative clastomcric impression
`materials. The polysulAde rubber impression material in(cid:173)
`troduced in the late l 950s, originally developed to seal gaps
`between sectional concrete structurcs,3 overcame some of
`the problems of the hydrocolloids. Nevenhclcss, polysul(cid:173)
`fide rubber was messy, possessed objectionable taste and
`odor, had long setting times intraorally, and underwent
`dimensional change after the impression was removed from
`the mouth, as a result of continued polymerization with the
`evaporation of water and shrinkage toward the impression
`tray, leading to dies that were wider and shoncr than the
`teeth being impressed.°' This problem was overcome some(cid:173)
`what by the use of custom trays that allowed for 4 mm of
`uniform space for the material and by pouring up the im(cid:173)
`pression within 48 hours.3
`The introduction in 1965 of the polyether material Im(cid:173)
`prcgum"' by ESPE, GmbH as the fim elastomcric impres(cid:173)
`sion material specifically developed for use in dentistry
`afforded the profession a material with relatively fut setting
`rime, excellent flowability, outstanding detail reproduction,
`adequate tear strength, high hydrophilicity, and low shrink~
`age. The material is still in use today in several formula(cid:173)
`tions, although it exhibits problems with objectionable odor
`and taste, high elastic modulus (stiffness) often leading to
`difficulty in removing impressions from the mouth, and the
`requirement to pour up models within 48 hours because of
`absorption of water in very humid conditions, which can
`lead to impression distortion.°'
`Condensation cure silicone impression materials subse(cid:173)
`quently were developed, but these also suffered from prob(cid:173)
`lc:ms with dimensional accuracy. The: creation of addition
`silicone vinyl polysiloune impression materials solved the
`is.sues of dimensional inaccuracy, poor taste and odor, and
`high modulus of elasticity, and offc:rl'<i c:xcdlent tear strength,
`superior flowabilty, and lack of distortion e\'c:n if modc:ls
`were: not pourc:d quickly. The biggest drawback of 1he poly(cid:173)
`siloxanc: impression materials, howc\'cr, is that tl1t.-)' arc
`hydrophobic. which c:111 lc.nl IO 1hc inahility to capture fine
`
`detail if problems with hemostasis and/or moisture control
`occur during impression making.
`In addition to the many problems inherent in the accura(cid:173)
`cy of the elastomeric materials themselves. funher distortions
`can occur by mistakes made in the mixing of the materials or
`in the impression-making technique, the we of nonrigid
`imprcssion trays, 5 the cransfer of the impression to the dental
`laboratory (often subjecting the impressions co variable tem(cid:173)
`peratures in everything from delivery vehicles to post office
`saning rooms to the holds of cargo jcu), the need for humid(cid:173)
`ity control in the denw laboratory to assure accuracy in the
`setting of the gypsum model materials, ere. Newer technolo(cid:173)
`gies that allow for the use of digiw scanners for impression
`making are indeed a welcome development. Digital impres(cid:173)
`sion making docs not require patients to sit for as long as
`7 minutes with a tray of often foul-wring and malodorous
`"goop" in their mouths, requiring mar they open uncomfort(cid:173)
`ably wide, often gagging. Funher, these devices help calm
`dentists' anxieties about economic and time considerations
`when deciding to remake inadequate impressions.
`Advances in computerization, optics, miniaturization,
`and laser technologies have enabled the capture of dental
`impressions. Three-dimensional (3D) digitizing scanners
`have been in use in dentistry for more than 20 years and
`continue to be developed and improved for obtaining virtu(cid:173)
`al impressions. The stressful, yet critical task of obtaining
`accurate impressions has undergone a paradigm shift.
`The computer-aided design/computer-aided manufu:ture
`(CAD/CAM) dental systems that arc currently available arc
`able to feed data obtained from accurate digital scans of teeth
`directly into milling systems capable of carving restorations
`out of ceramic or oompositc resin blocks without the need. fur
`a physical replica of the prepared, adjacent, and opposing
`teeth. With the development of newer high-strength and cs(cid:173)
`thc:tic ceramic rcstorati\-c materials, such as zirconia, laborato(cid:173)
`ry techniques have been developed in which master models
`poured from elastic impressions arc digitally scanned to cn::-atc
`stercolithic models on which the restorations are made. Even
`with such high-tech improvements, it is evident that such
`second-generation models arc not as accurate as stereolithic
`models made directly from data obtained from .~D digital
`scans of the teeth pro\'idcd by d1.-<licatcd 3D scinners d1.~ign1.-<l
`for impression making. This article ourlinc:s the features of
`two CAD/CAM systl·ms and two dc<lk.ncd 3D imprcssion(cid:173)
`in~ digital scanm·rs that han· bt'cn g.1i11in~ in populari1y in
`rhis cmt·r~t'nt fldd of rcrhnoln~y.
`
`0002
`
`Exhibit 1039 page 2 of 10
`DENTAL IMAGING
`
`

`

`Digital Dentistry
`
`C E RE C 3
`
`Figure 1 The CEREC 3 imaging unit. As a CAD/CAM system,
`the product also includes a separate, newly upgraded
`milling unit, the MC XL
`
`Figure 2 The CEREC 3 camera. The new software used in
`the system includes a camera crosshair, which makes the
`optical impression easier and more predictable.
`
`Figure 3 For dentists preferring a complete chair/systems
`arrangement, the CEREC 3 is now included as part of the
`CEREC Chairline integrated un it .
`
`CAD/CAM SYSTEMS
`CAD/CAM technology has been in use for a half century. It
`originated in the 1950s with numerically concrolled ma(cid:173)
`chines feeding numbers on paper tape into controUers wired
`to motors positioning work on machine tools. It ad\-ancc:d
`in the 1960s with the creation of early computer software
`that enabled the design of products in the aircraft and auter
`motive industries. The introduction of CAD/CAM con(cid:173)
`cepts into dental applications was the brainchild of Dr.
`Francois Duret in his thesis written at the Universite Cuudc
`Bernard, Facultc d'Odontologie in Lyon, France in 1973.
`encicled "Empreinte Optique" (Optical Impression). He de(cid:173)
`veloped a CAD/CAM device, obtained a patent for it in
`1984,6 and brought it to the Chicago Midwinter Meeting in
`1989. There, he fabricated a crown in 4 hours as attende-c:5
`watched. In the meantime, in 1980, a Swiss dentist, Dr. Wer(cid:173)
`ner Mormann and an eleccrical engineer, Marco Brandc:stini
`developed the concept for what was to be introduced in
`1987 by Sirona Dental Systems LLC (Charlotte, NO as che
`first commercially viable CAD/CAM system for the fubrio(cid:173)
`tion of dental restorations-CEREc•.
`
`CEREC
`The CEREc• 3 system (Figure 1), an acronym for CJuir(cid:173)
`side Economical Restoration of Esthetic Ceramics, was .1
`bold effort to combine a 3D digital scanner (Figure 2) \\ith
`a milling unit to create dental restorations from commer(cid:173)
`cially available blocks of ceramic material in a single ap(cid:173)
`pointment. One-appointment direct dental restorations
`eliminated the need for multiple visits, as well as for tempo-
`rization and all of its inherent problems. The CEREC S\~-
`tern uses computer-assisted technologies, including 30
`digitization, the storage of the data as a digital model. and
`proprietary CEREC 30 software that proposes a rcsror:i·
`tion shape based on biogeneric comparisons to adjacen1
`and opposing teeth, and then enables the dentist to modifr
`the design of the restoration. After this is accomplished, the
`data is transmitted to a milling machine, the latest version
`of which, CE REC inL1b •Mc XL, is capable of milling 2
`crown in as little as 4 minutes from a block of ceramic or com·
`posite material. The most current version of the CE REC 3
`acquisition unit is integrated into a coral chair/systems unit,
`the CEREC Chairlinc (Figure 3).
`Wi1h this sym:m, 1he impressioning process necessimcs
`achie\'ing adcqua1e '"i ualization of the margins of the tooth
`pn:parati o n hr proper rissue retraction or troughing ~nd
`
`1
`
`,
`
`1
`
`1
`
`'
`
`0003
`
`Exhibit 1039 page 3 of 10
`DENTAL IMAGING
`
`

`

`hemostasis. The entire area being impressed needs to b,e
`coated completely with a layer of biocompatible titanium
`dioxjde powder to enable the camera to register all of th1e
`tissues. This is true not only for digital scanning, but alsc>
`for conventional dastomeric impn:ssions as well
`Several image views then arc made from an occlusal orien(cid:173)
`cation as.ruring capture of the tooth or teeth being restored, as
`well as of the adjacent and opposing teeth. Next, the prepara(cid:173)
`tion is shown on a touch screen that enables the dentist t<>
`view the prepared tooth from every angle and to focw on
`magnified areas of the preparation. The "die" is "cut" on th1:
`,;nual modd, and the finish line is ddinc.atcd by the dentist
`directly on the image of the die on the monitor screen. Then,
`the CAD biogeneric proposal of an idealized restoration i:s
`presented by the system, and the dentist is given the opportu•
`nity to make adjustments to the proposed design using ;a
`number of simple and intuitive on-screen tools (Figure 4).
`After t.hc: dentist is satisfied with the proposed restora·•
`tion, he or she mounts a block of homogeneous ceramic oir
`composite material of the desired shade in the milling uni1r
`and proceeds with fabrication of the physical restoration.
`The use of color-coded tools during the design stage of the:
`process to determine: the degree of interproximal contac1r
`helps to assure finished restorations that require minimal,
`if any, adjustments before cementation.
`
`E4D Dentist
`D4DTechnologies LLC (DalJas, TX), an acronym for Dream"
`Design, De\'elop, Deliver, introduced the E4D Dc:ntistn'
`CAD/CAM system in early 2008, after an extended period!
`of beta-testing and fine-tuning to assure a quality product. 11:
`consists of a cart containing the design center (computer andl
`monitor} and laser scanner (Figure 5), a separate milling unit"
`and a job server and router for communication. The scanner,,
`termed the IntraOral Digitizer, has a shorter verticil profile:
`than that of the CEREC system, so the patienr is not re··
`quired to open as wide for posterior scans.
`Of significance, the E4D Dentist does not require: the:
`use of a reflecting agent, such as titanium dioxide powder,,
`to enable the capture of fine detail on the target site. Other
`CAD/CAM systems create a digital "gypsum" model on
`which the restoration is made. While the E4D Dentist can
`create such models when the sc:inner is used on eitJ1er acmal
`gypsum models or ela.scomcric impressions, ir creates a more·
`accurate an<l informaciw modd when scanning is done wiLh
`rhe InrraOral Digitizer (Figure 6).
`
`Birnbaum and Aaronson
`
`Figure 4 A screen shot of an onlay restoration proposed by
`the software library. User-friendly tools permit refinement
`of the restoration before milling.
`
`Figure 5 The E4D imaging unit. The CAD/CAM system also
`includes a separate milling unit for fabricating restorations.
`
`0004
`
`Exhibit 1039 page 4 of 10
`DENTAL IMAGING
`
`

`

`Digita l! Dentistry
`
`The ICfaerything"" (ICE) fearure of the system's Denta(cid:173)
`Logic"' software takes acrual picrures of the teeth and gingi\'a
`before treatment and after tooth preparation, as well 3S an
`occlusal rc:gistration. As successh·e picnires arc taken, they arc
`wrapped ~tround the 30 model to create the ICE model. The
`30 ICE view makes margin detection simpler to achieve
`(Figure 7)1. The touch screen monitor enables the dentist to
`view the preparation from ,·:uious angles to assure its accuracy.
`The design system of the E40 Dentist is capable of auto(cid:173)
`detecting and marking the finish line on the preparation. Af(cid:173)
`ter the dentist approves this landmark, the software uses its
`Autogenesis"' fe.arure to propose a restoration, chosen from its
`anatomical libraries, for the tooth to be restored (Figure 8).
`
`As with the CEREC system, the oper:ator is prO\·ided '\\ith
`a number of highly intuitive tools to modify the: rcsron(cid:173)
`tion proposal. After the final restoration is approved, che
`d,esign center transmits the data to the: milling machine.
`Using blocks of ceramic or composite mounted in the mil(cid:173)
`ling machine, and with the aid of rotary diamond instru(cid:173)
`ments that can replace themselves when worn or damaged. I
`I
`the dentist can fabricate the physical restoration.
`
`,
`
`C>EDICATED IMPRESSION
`SCANNING SYSTEMS
`Dedicated 30 digital dental impression scanners diminlce
`sc:veral time-consuming steps in the dent:al office. including
`
`Figure 6 The lntraOral Digitizer, which does not require the use of a reflecting powder to capture images, ca,n be used to scan
`teeth, mc,dels, or elastomeric impressions.
`
`0005
`
`Exhibit 1039 page 5 of 10
`DENTAL IMAGING
`
`

`

`I .
`I I
`1
`
`tray selection, dispensing and setting of materials, disinfec(cid:173)
`tion, and shipment of impressions to the laboratory. In
`addition, the: laboratory saves time by not having to pour
`base and pin models, cut and trim dies, or articulate casts.
`With these: systems, the: final restorations arc produced in
`the laboratory, but they arc: fabricated on models created
`from the data in the: digital scans, as opposed to gypsum
`models made from physic.al impressions. Patient comfort,
`treatment acceptance, and education arc added benefits.
`Digital scans cm be: stored on computer hard drives indc:fi(cid:173)
`nitc:ly, whereas conventional modc:ls, which may chip or
`break, must be stored physically, which often requires extra
`space in the dental office.
`
`iTero
`The iTcro,.... digital impression system (Cadent, Carlstadt,
`NJ) was introduced in early 2007. following 5 years of in(cid:173)
`tensh•e research and beta-testing. Based on the: theory of
`"paralld confoc:a1," the iTcro scanner emits a bc:am of light
`through a small hole, and any surface within a certain dis(cid:173)
`tance will rdlc:a the: light back toward the wand. The: iTc:ro
`device projc:as 100,000 beams of red light, and within one
`third of a second, the reflc:acd light is convened into digital
`data. There is no need for the use of a reflecting agent, such
`as titanium dioxide powder, as the laser is able to reflect off
`all oral strucrurcs.
`The iTero system includes a computer, monitor, mouse,
`integrated keyboard, foot pedal, and scanning wand organ(cid:173)
`ized on a well-designed mobile can (Figure 9). Disinfection
`consists of replacing the disposable sleeve on the handhdd
`scanner (Figure 10). The end of the scanner that enters the
`mouth has the tallest \'Crtical profile of the systems reviewed
`in this article (Figure 11 ), and thus requires wider mouth
`opening by the: patient.
`Voice prompu guide the dentist in taking a series of
`scans of the patient's teeth and ocdusal registration. The
`images arc: captured on the monitor by stepping on the foot
`pedal. The image on the screen is similar to a viewfinder
`on a camera, which allows the dentist to position the cam(cid:173)
`era correctly while looking at the screen. As this is not a
`continuous scan and no powdering is necessary, the dentist
`may remove the scanner from the mouth to dry or rinse
`fluids as neccssary.7 Individual images may be retaken to
`ensure: capture of adequate detail. If the preparation must
`be: modified, the quadrant needs IO be rescanned after all
`adjustments arc complctc.11
`
`Birn baum and Aaronson
`
`Figure 7 30 ICE view of a prepared tooth derived from the
`ICEverything feature of the Dentalogic software from pre(cid:173)
`and postoperative scans.
`
`Figure 8 The Autogenesis feature of the E40 system pro(cid:173)
`poses a restoration, which can be enhanced by the opera(cid:173)
`tor with simple onscreen tools before milling.
`
`After all scans (at least 21) are completed, the dentist
`steps on the foot pedal and, within a few minutes, the digi(cid:173)
`tal model is displayed on the monitor (Figure 12). Using a
`wireless mouse, the dentist can rotate the: model on the
`screen to confirm that the preparations are satisfactory be(cid:173)
`fore temporizing the teeth and sending the scans to the lab(cid:173)
`oratory. Voice prompts again are very helpful in assuring
`that such necessities as proper occlusal tooth reduction for
`the intended crown r:ypc have been achic\'ed,
`All patient data and laboratory prescriptions arc input in(cid:173)
`to the computer before the: scanning procedure. Digital data
`arc sent wirclcssly to Cadent, where the digital impression is
`
`0006
`
`Exhibit 1039 page 6 of 10
`DENTAL IMAGING
`
`

`

`Digital Dentist ry
`
`Figure 9 The iTero 30 digital impression system. Scan data of
`preparations are e-mailed wirelessly to Cadent for creation of the
`model .• which then is sent to the laboratory for the restoration.
`
`Figure 10 iTero's handheld digital scanner does not require
`the use of a titanium dioxide reflecting agent to capture
`digital images of hard and soft tissues.
`
`refined and a hard plastic model is milled. Cadcnc chen
`recurns the model ro che local denial laboratory, which
`comple1es the final restoration .9
`
`Lava C.O.S.
`The L:w:i ... Chairside Oral Setnncr (C.O .5.) wa.-; horn 011t of
`the research of Professor Doug Ha n :rnJ D r. J:i nos Roh.ily
`
`at the Massachusccts Institute of Technology. The Lan
`C.O.S. was created at Brontcs Technologies Inc (Lexington.
`MA) and was acquired by 3M ESPE (St. Paul, MN) in Oc(cid:173)
`tober 2006. The product was launched officially at the Gu(cid:173)
`e.ago Midwinter Meeting in February 2008.
`The method used for capturing 3D impressions imohts
`active wavefront sampling (AWS), which enables a 3O-in(cid:173)
`Motion technique. This technique incorporates revolution(cid:173)
`ary optical design, image processing aJgorithms, and ral(cid:173)
`time model reconstruction to capture 3D data in a "idco
`sequence and model the data in real time. Other digica.l im•
`pressioning scanners use triangulation and laser appro:ich~
`which rely on the warping of a laser or light patrern on a.n
`object to obtain 3D data. In so doing, these methods arc
`relati vely slow and have the downside of distortion ;md
`optical illusion. By usingAWS, howe,•er, the LAVA C.O.S.
`captures scanned images quickly (approximately twcnry 3D
`data sets per second, or close to 2.400 data sets per arch) in
`video mode and creates a highly accurate virtual on-scm:n
`model instamanc:ously. 10
`The: l.a,'3 C.O.S. unit consists of a mobile cart (Figure 131 1 _
`containing a computer, a touch screen monitor, and a SC2Il(cid:173)
`ning wand (Figure: 14), which has a 13.2-mm wide rip and I ··
`weighs 14 oz (about the size of a large power toothbrwh). 1 •r
`The end of the: scanner that enters the mouth is chc: smallest
`of the systems reviewed in this article. The cuncr.1 at the: 1ip
`of the wand (Figure: 15) contains 192 light-cmirting diodo
`(LEDs) and 22 lensc:.s. There is no need for a keyboard or
`mouse, as the monitor displays a keyboard for all data in- I ·,
`put. Disinfection im·ol\'es a simple wipe down of the mon-
`itor with an intermedi:ue-le,•el surf.ice disinfectant dcsign(d 1 •
`I ;,
`for use on nonporous surfaces and replacement of the plJS-
`tic sheath on the wand.
`Whereas the Cadent iTero docs not rcquirt: any powd(r-
`ing and the CEREC requires hea\'y powdering, the Lan
`C.O.S. requires only enough powdering to allow the san·
`ncr to locate reference points. Therefore a \'Cry light dusting
`of powder is required, and is produced using the powdering
`gun pro"ided with the: unir.
`Following preparation of the tooth and gingi\"al re1r.1,(cid:173)
`tion (if necessary), the entire arch is dried thoroughly anJ
`lightly dusted with powder. The dentist begins scanning b~·
`press ing either a button on the sc;inning w-and or the sort
`key on the touch screen monitor. A pulsing blue lighc cm(cid:173)
`a n .lll'S fro m the wa nd head as a bbck and white ,·idc:o of the
`ll'l'th :1r1w,1rs in.,1:uu.1111:ously on the monitor. Starting on
`
`j .,.
`
`1
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`0007
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`Exhibit 1039 page 7 of 10
`DENTAL IMAGING
`
`

`

`Birnbaum and Aaronson
`
`figure 12 Typical screen shot of a prepared arch, which may
`be viewed at any angle using the wirelMS mouse.
`
`Figure 13 The Lava Chairside Oral Scanner (C.O.S.). Note the
`absence of a keyboard because data entry and laboratory
`prescriptions are done onscreen.
`
`~ Figure 11 iTero's scanner is used intraorally to capture lndi•
`vidual 3D images as the dentist follows voice prompts to
`assure accurate scanning and occlusal clearance.
`
`• the occlusal surf.tee of any posterior tooth, the demist guides
`-• the wand forward over the ocdusal surfaces of the sextant
`~· being scanned, and then rotates the w.md so that the buccal
`-:-
`surf.aces arc ciprurcd.
`The wand thc:n is mo,•c:d posteriorly, capturing all chc:
`_; buccaJ surf.aces with some o\'erlap of the occlusal. After he or
`she reaches the most posterior tooth, the dentist begins scan(cid:173)
`·f' ning the lingual surfaces of all the teeth in the sextant. The
`_ .. stripe scanning" is completed when the demise returns to
`scanning the occlusal of the staning tooth, ie, "closing the
`., loop." If any sudden mo\'ement occurs, the image auto ma ti(cid:173)
`,, ally pauses and the dentist can continue by returning to any
`surface that has been previously scanned. The software rec-
`ognizes data that is already in the computer and resumes
`scanning without the need for pressing any buttons. Ad(cid:173)
`ditionally, the software can distinguish between surfaces chat
`arc intended to be scanned (ie, teeth and attached gingiva)
`and extraneous data (ie, tongue, cheeks, etc).
`As the teeth are scanned, they turn bright white on the
`·· monitor, and any areas that remain in red need to be scanned
`for more detail. To help the dentist maintain rhe wand at a
`proper distance from the teeth, a target appears on the mon(cid:173)
`itor to indictte whether the wand is too dose or too far away
`from the teeth. With the help of these on-screen guides, the
`dentist can modify the continuous scan without pausing,
`·· withdrawing r.hc wand, or restarting the scan.
`After scanning rhe preparation and adjacent rc:crh, the
`dentist pauses the scan and evaluates the result on the mon(cid:173)
`itor. He or she is able to rotate and magnify the view on the
`screen, and also switch from the 3D image to a 2D \'iew of
`the exact images captured by the camera during the scan. A
`
`;,
`
`0008
`
`Exhibit 1039 page 8 of 10
`DENTAL IMAGING
`
`

`

`Digital Den t istry
`
`Figure 14 The lava C.O.S. camera has the smallest wand of
`any of the reviewed systems, making access to all parts of
`the oral cavity easier to achieve.
`
`Figure 15 The tip of the wand contains 192 LEDs and 22
`lens systems and captures impression and occlusal registra•
`tion data in video mode.
`
`Figure 16 Typical screen shot of a prepared tooth. In addi•
`tion to the image shown, the dentist and laboratory technl•
`cian can view it in stone cast mode or with 30 glasses.
`
`third option aJlows the dentist co view these images while
`wearing 30 glasses.
`After the dentist confirms chat all necessary derails were
`captured on the scan of the preparation (Figure 16), a quick
`scan of che rest of che arch is obtained, which rakes approx(cid:173)
`imately 2 minutes. If there arc holes in the scan in areas
`where data is critical, such as cusp tips or con race points, it
`is not necessary co redo the entire scan. Rather, the dentist
`simply scans chat specific area and the software patches the
`hole. The sofcwarc: uses reference points on the scanned
`images to integrate: chc: new data with that of the previow
`scans; thc:rc:forc:, it is crucial co have some overlap when
`scanning new data.
`After the opposing arch is scanned, the patient is in(cid:173)
`structed to close into maximal intc:rcuspaJ position. The
`buccal surfaces of the teeth on one side of the mouth arc
`powdered, and a 15-sccond scan of the occluding teeth is
`captured. The maxillary and mandibular scans then arc di(cid:173)
`gitally aniculatcd on the screen.
`After all the scans have been reviewed for accur:icy, the
`dentist uses the touch screen monitor to complete an on(cid:173)
`screen laboratory prescription. The data is sent wirdcssly to
`the laboratory technician, who then wcs cwtomizcd soft(cid:173)
`ware to cur the die and mark the margin digitally. 3M ESPE
`receives the digital file where it is ditched virtually, and the
`data is articulated seamlessly with the operative, opposing,
`and bite scans. Ac the model manufu.ccuring fu.cilicy. a stcrc(cid:173)
`olithography model is generated, and is sent to the labora(cid:173)
`tory (along wich a La,1a coping if the restoration is to be a
`Lava crown), where chc: technician creates che final restora(cid:173)
`tion. Despite the name of the system, it is not dedicated
`only co the creation of Lava crowns, as all types of finish
`lines may be reproduced on the scereolithography dies,
`allowing for any type of crown to be manufactured by the
`dental labor:uory.
`
`LEARNING CURVE
`All of the 30 digital impressioning systems rc\'iewcd in this
`article have the potc:mial to produce: restorations with im(cid:173)
`proved marginal flt m·er that of traditional c:lastomeric im(cid:173)
`pressions, based on the face chat the master die is created
`from digital data obtained from the tooth preparation,
`rather than from a second- or chir<l-gc:nc:ration impression
`or model. The success of the CE.REC system o\'er che past
`21 years in con\"incing many dentists worldwide rn eng-Jge
`in new tc:chnologic:s bodes well for the: future of all of the
`
`0009
`
`Exhibit 1039 page 9 of 10
`DENTAL IMAGING
`
`

`

`systems that have bec:n and will continue to be developed.
`One of the factors that prevent dentins from "taking off the
`blinders" and attempting to inuoduc:c new techniques and
`instruments into their dental practices is the fear that the
`learning curve is too great and that "you can't teach an old
`dog new tricks."
`Recent research advanced by No1rman Doidge 11 shows
`that neuroplastidry in the brain exists throughout the hu(cid:173)
`man lifespan and that the cerebral co,ncx is capable of con(cid:173)
`stantly undergoing improvements in cognitive functioning.
`This means that any wk that requires highly focused atten(cid:173)
`tion or the mastery of new skills helps to improve the mind,
`especially memory. Admittedly. learning to use any of the
`digital scanners discussed in this anicle means acquiring
`new skills and mastering new techniques, which will take
`some time and patience. The bottom line, however, is that
`the end result of developing the abiliry to use these new
`technologies will empower dentists tc> learn more about the
`dentistry they perform and enable rthem to provide their
`patients with well-Atting restorations.
`
`THE ECONOMICS
`The cost of all the systems presented, ranging from just over
`$20,000 to well O\'Cr $100,000. may appear prohibitive for
`many, if not most, small dental pr;actices. Nevertheless,
`when all of the attendant costs of traditional impression(cid:173)
`making arc taken into account, including the frequent need
`to remake impressions or e\'en remake restorations as a
`result of the shoncomings of the older techniques and ma(cid:173)
`terials, and considering the improved qualiry of restorations
`made possible by the newer digiw systems, the 30 digital
`imprcssioning systems become more appealing. The lease
`programs offered through most CAD/CAM system manu(cid:173)
`f2cturers have brought using this technology into the realm
`of profitability for practices produci1:1g more than 14 indi(cid:173)
`rect restorations a month.
`Notwithstanding the ethical dilemma of dentists' pro(cid:173)
`viding indirect ceramic restorations when simpler and less
`expensive composite restorations an: achievable simply to
`justify the lease expenses of an c:xpcnsi\'c: digital system, the:
`use of new an