CLINICAL

COMMENT THEUNIVERSITYOF CHICAGOHOSPITALS

WI NTER

2000

CARDIOLOGY

ANNOUNCEMENTS

VASCULAR SURGERY

Figure 1. The

Amplatzer

septal accluderconsists of two

flat disks and aconnecting waist

and ranges from4 to 38 mm.

Surgery for ASD using a midsternotomyapproach is safe, with very low mortality(<1 percent). However, patients experiencesignificant morbidity (scar, hospitalization for3 to 5 days, pelicardial effusion, and post­pericardiotomy syndrome) and the closure rateis not 100 percent.

The era of nonsuf/.,rical transcatheter closureofASD began in 1975 when King and Millslreported on the use of double umbrellas toclose a hole in a 17-year-old young adult. Thelarge introducer size needed to insert theumbrella (22F) precluded the use of thisdevice in most pediatric patients; however, thefeasibility of nonsurgical closure of ASD wasdemonstrated. Subsequently, several devices

Secundum atrial sept<tl defect (ASD) , acommunication between the upper chambers(right and left atria) of the heart, accounts forapproximately 10 percent of all forms ofcongenit<tl heart disease. It can be an incidentalfinding in children and young adults and cancause shortness of breath, congestive heartfailure, and pulmonary vascular obstructivedisease in adults.

by Ziyad M. Hijazi, MD, MPH, FACCChief, Section of Pediatric CardiologyDirect01; Cardiac Catheterization Laboratory

Professor of Pediatrics and MedicineUniversityafChicago(773) 702-6172

zhijazi@jJeds.bsd. uchicago.edu

Nonsurgical Closure of Secundum AtrialSeptal Defects in Adults and ChildrenUsing the Amplatzer Device

EDUCATION CALENDAR

CONTINUING MEDICAL

CLINICAL TRIALS

ORAL SURGERY

Page 10

Dental Implant UpdatePage 6

New MultidisciplinaryCenter for Research Into

Inflammatory andAutoimmune Diseases

Page 9

Growing to Serve theSouth Side Better

Page 9

New Resource for PeopleWith Asthma

Page 10

New Initiatives in

Minimally InvasiveVascular SurgeryPage 3

TABLE OF

CONTENTS

Page 12

NEW ApPOINTMENTS

Page 12

continued on

next page

Dental Implant Update

r

NEW INITIATIVES IN MINIMALLY INVASIVE VASCULAR SURGERY

continued from page 5

have led to the initiation of a Phase II randomized

clinical trial using this device, and we are currentlyenrolling patients at The University of Chicago(IRB protocol #9207).

References

1. Clark ET. Gewertz III., lIassiouny HS. Zarins CK. Current resulLs of

aortic reconstruction for (tncUI)'smal and occlusive disease.} Cardimmsc

Surg.1990;31;438-447.

2. Baldwin ZK. ~Ieyerson SL. McKinsey JF, et .11. Estimating the

contemporary in-hospital costs of carotid endanerectomy. Ann \fasfSurg. (In press.)3. Schwartz LB, Belkin ~I, Donaldson MC, et .11. Validation of a new

and specific intraoperativc measuremcnt of vein graft rcsistaurc ../ VaseSurg.1997;25:1033-1043.

4. Jordan WD,Jr.. Voellinger DC, Fischer WS, Redden D, McDowell

IIA. A comparison of carotid angioplasty with stenling vcrsus

endarterectomy with regional anesthesia. J Vase Surg. 1998;28:397~1O:~.

5. Tegtmeyer q, Hartwell GD, SelbyJB, RoherLson R,Jr., Kron [I.,

Tribble CG. Results and complications of angioplasty in aortoiliacdisease. Circulation. 1991;83[1]:[53-160.

6. Stanley B, Teague B, Raptis S, Taylor [jJ, Berce M. Efficacy of

halloon angioplasty of the supedicial femoral artery and popliteal

artel)' in the rdief of leg ischemia. J Vasc Surg. 1996;2:~:679-685.

7. Rosenthal D, Herring NIB, O'Donovan TG, Cikrit DF, Comerota AJ,

CorsonJD. Endovascular infraillguillal in situ saphenous vein h)1)ass:Amulticenter preliminary report. J Val( Surg. 1992; 16:453A58.

8. Rosenthal D, Dickson C, Rodriguez F], et al. [nfrainguinal

cndovascular in situ saphenous vein bypass: Ongoing results ..1 VavSurg. 1994;20:389-395.

9. Dubost C,Allary M, Oeconomos N. Resection of an aneurysm ofthe abdominal aorta: Reestablishmcnt ofthc continuity hy presen:edhuman arterial graft, with result after live months. Arch Surg.1952;64:405-408.

10. Schwartz LB, Belkin ~I, Donaldson MB, Manni"kJA, Whittemore

AD. Improvement in rcstllt~ of repair of type IVthoracoabdomillalaortic anelll)'sms. J Vm( Swg. 1996;24:74-81.

11. ~IcCann RL, Schwartz LB, Georgiade GS. Management of

abdominal aortic graft complications. Ann Surg. 1993;217:729-734.

12. Naylor AR, Bolia A, Ahbott ~I,et al. Randomized study of carotid

angioplast)' and stenting \'ersus carotid cndarterectomy: A stoppedtrial. J Vase Surg. J 998;28:32(>-334.

13. Jordan WD, Schroeder PT, Fisber WS, McDowell I I. A compari­

son of angioplasty with stenling versus endarterectomy for thclreatmCltt of carotid artery stcnosis. Ann Vase ,'·urg. 1997; 11 :2-R14. Jordan WD,Jr., Roye GD, Fischer \\'S, III, Redden D, ~kDowdl

t-IA.A cost comparison ofhalloon angioplasty and stenling vcrsusendartcrectomy for the treatment of carotid artery stenosis ..1 Vase Surg,1998;27: H>-24.

1S. Piano G, S~hwarlz LB,Foster L, et al. Assessing the outcomcs,cost~, and benefit.;;of emerging technolohT)'for minimally-invasivesaphenous vein in-situ distal arterial bypass. Anh Surg. 1998;J:n:613­617.

16. ParodiJC, PalmazJC, Barone HD. Transfcmoral intralumiual

graft implantation for abdominal aortic ancurysms ..1VaJ'e Smg.

1991;5:491-499.

17. Zarins CK, \\1,ite RA, Schwarten D, et al. AneuRx stent graft

versus open surgical repair ofahdominal aortic aneUl)'sms: ~llllticcnterprospective clinical trial../ Vfl.5(Swg. 1999;29:292-:\08.

18. Mialhe C, Amirabile C, lIec'luemin JP. Endovascular treatment of

infrarenal abdominal aneurysms hy the Stcntor system: Preliminaryresults of 79 cases. J Vase Surg. 1997;26: 199-209.

19. \\1,ite GH, Yu W, MayJ, et al. Three-year experien"e with the

\\'hite-Yu endovasullar GAD graft for transluminal repair of aortic andiliac aneurysms. J Etlltovase Sllrg. 1997;4: 124-136.

6Visit our web site:www.uchospitals.edu

ORAL SURGERY

by L. Eric Pulver, DDS, FRCD(C)

Clinical Associate Professor and Chief

Oral and Maxillofacial SurgeryUniversity of Chicago(773) 702-6811, (773) IMP-LANT

epulver@surgery.hsd. uchicago.edu

HISTORY AND BACKGROUND

Dental implantology was introduced in Sweden inthe late 1960s and in North America less than adecade later at four medical! dental centers. Recent

advancements resulting from research and clinicaltrials have made dental implant~ often the treat­ment of choice to replace missing teeth.

Implant~ are made from titanium, which is ex­tremely biocompatible and allows forosseointegration into the human body. A dentalimplant is a titanium root form that is gently placedinto bone and acts as a stable support fiJr a pros­thetic tooth or denture. It eliminates the mobility,discomfort, and difficulty associated with partialand complete dentures. An implant can eliminatethe need to reduce healthy tooth structure when abridge has to be constructed. They are predictable,safe, and successful. Studies have shown success

rates of slightly less than 100 percent, dependingon the selected site of placement.'

According to the American Dental A~sociation,more than 100 million people in the United Statesare missing from 10 to 15 teeth. Fifty millionAmericans are missing all of their teeth. TheNational Health and Nutrition Exam Slllvey IIIreports that 57 percent of the American populationbetween the ages of65 and 74 years use dentures(www.demographics.com). These patients oftensuffer from loss of self~steem and confidence. Theyoften refrain from smiling, laughing, and eating the{(>ods they enjoy. Patients with dental implant~regain their confidence by once again having fixedteeth. These teeth don't require much more carethan natural teeth. Dental implants can provide along-term, ifnot permanent, alternative to bridgesand dentures. The average bridge lasts from 6.2 to11.2 years, owing to recurrent decay and mechani­cal material barriers.~ Patient~ who currently have asingle crown may have to face the decision ofwhether to have a bridge or an implant placedwhen their crown fails.

More than

100 million

people in theUnited States

are missingfrom 10 to

15 teeth.

]

"

Dental implanL~ offer the stability and confidenceof natural teeth. They can be used to securelysupport a traditional complete denture. ImplanL~also can be used to replace a single missing tooth.In many cases they can be used to replace an entiredentition as a fixed, nonremovable restoration.

Many options are available and can be tailored toindividual patient needs. The results are aestheti­cally pleasing and long-lasting, and often preservehealthy tooth structure when compared withtraditional treatment. Recent advancements in

dental implantology have increased the use of thistechnology as a reliable form of tooth replacement.

Figure 1. Mandible with five implantsstandard abutments, and a fixed,removable bridge (hybrid).

Figure 2. Crass-section of pillarwith CerAdapt™ abutment. Mk/lfixture, CerAdapt, and crown.

Table General Comparison of Various Treatment Options*

Implant Bridge

Longevity, y 10-30t 6.2-11.21

Healthy-tooth reduction No Yes

Endodontics No Yes, 20%-30%§

Routine hygiene Yes Yes

Patient visits/year 2-8 3-4

Mobility No No

Recurrent decay No YesPressure ulcer No No

Improved chewing ability Yes Yes

Bone-loss prevention Yes No

Time to complete treatment, wk 8-52' 4-6

* All values may vary, depending on the complexity of the case.t Refers to implant longevity only.:\: Insurance companies, on average, cover a crown or bridge every 5 years; thus, a longevity of 5 years is expected.

§ A total of 20 percent to 30 percent of all teeth prepared for a crown or bridge will require an endodontic procedure.~ A single-tooth implant requires 8 weeks to complete the restoration; full maxillary recon.st!:,uction requires IOta 12 months tocomplete the restoration.

(usually in 4 months). In selective cases, studieshave indicated a 96 percent to 98 percent successrate with 2-month placement and loading of theprovisional or final restoration.3

Immediate imPlant placelnent - In many situations,such as teeth with one root, an implant can beplaced at the time of extraction. The tooth canbe measured to determine the dimensions of the

implant to be used. Bone grafting may be neces­s,uy at the coronal aspect to fill any voids. Inselective cases, an immediate implant can beperformed in one stage.

Osteotome technique- Osteotomes can be used tosequentially enlarge and compress an implant

RECENT ADVANCEMENTS

Single-stage s1llgelY - Single-stage surgery hasbecome more widely practiced. Ifan implant isstable on placement, a tissue-forming healingabutment is placed immediately. This eliminatesthe 6 weeks of tissue maturation necessary after thetraditional two-stage surgery. Two-piece healingabutments can now be used to minimize looseningduring the healing phase. The anatomicallycontoured healing abutments can aid in optimizingemergent profile charactelistics. This procedureaids in reducing the waiting time for a provisionalor final restoration. Surgical indexing can beperformed at the time of surgery or after 6 weeks.A provisional restoration can be prepared in thelaboratory and placed following integration

Call toll-free 1-800-UCH-2282to contact our physicians.

Full Denture

5-7

No

No

Yes

5-7

Yes

No

Yes

Yes, temporaryNo

4-6

Partial Denture

5-7

Yes

No

Yes

6-7

Yes

No

Yes

Yes, temporaryNo

4-6

continued on

next page

Recent

advancements

in dental

implantologyhave

increased the

use of this

technologyas a reliable

form of tooth

replacement.

7

DENTAL IMPLANT UPDATE

continued from poge 7

The emer­

gence of bone

morphogenic

protein as a

viable,

predictable,

and successful

alternative to

traditional

bone grafts

holds great

promise forthe future.

8

preparation. Since rotary instrumentation isreduced, hard-tissue trauma seconcl<uy to excessiveheat is minimized. In many situations, a pilot drilland the 2 mm twist drill are'all that are necessalYplioI' to using the osteotomes. Osteotomes alsocan be used to widen a thin ridge (3 mm ridge)and ped()rm minor sinus-lift procedures."

Bone gnljiing- Traditional bone grafting hasbecome much more atraumatic. The ability toobtain sufIicient bone for minor sinus lifts under

local anesthesia has increased patient acceptanceof these procedures. The emergence of bonemorphogenic protein (BMP) as a \iable, predict­able, and successful alternative to traditional bone

grafts holds great promise for the future. At theUniversity of Chicago we currently are studyingBMP related to sinus lift~. Human recombinant

BMP is merely reconstituted in saline and placedinto the sinus on a resorbable carrier. This

eliminates the need for a second surgical donorsite. Bone growth is induced, which can thenmaintain an implant.

Pmsthetics- Prepable ablltment~ are now avail­able. They can be placed after the healing abut­ment is removed. The abutment can be preparedin the laboratOlY. Minor adjustment~ can be doneat chair side, similar to routine crown preparation.A traditional temporalY crown can be made untilthe final restor.ttion is ready for cementation.

ImjJlrmttopognljJhy - The implant sud'ace texturehas been the center of attention recently asresearchers explore the theory that increasedroughness may be related to increased bone-to­implant contact. The fiblin formed by a combina­tion of thrombin and fibrinogen initially adheresto the implant surface. Surface roughness isthought to allow adherence of the clot to theimplant during the retraction phase of healing."This results in increased bone-ta-implant contact.Current surfaces may be roughened by acidetching, glit blasting, titanium plasma spray,machining, or hydroxyapatite coating.

lmPlant design- Implants are available in variousdiameters and tapers to more anatomicallyresemble the teeth they are to replace. Widerdiameter platforms withstand tipping forces andprmide greater surface area f()r osseointegration.

Antirotation - Attention to reducing crownloosening has led to changes in implant design.The external hex has been tapered and length-

ened in some product~. Others have deepened theinternal hex and added a morse taper to achieve ahiction fit. This taper has shown to achieve a coldweld on scanning electron microscopy images.l;Screw loosening has been reduced and screwtechnolob'Y has improved.

Postextraction preservation - A]veolar ridge heigh tand \\idth are lost after an extraction. To maintain

proper bone volume and anatomy, an alloplasticbone graft Inay be necessalY. Grafting may allowfor proper contours around an implant or be­neath a bridge.

PeriodontaljJlastic surgery - Subepithelial connec­tive tissue grafting can be used to augment soft­tissue contours. Preselvation of the dental papillais considered essential when designing surgicalincisions. Where possible, only a minimal flap israised, to avoid disturbance of soft-tissue anatomy.

Although the length of treatment for dentalimplant~ is greater than traditional tooth-replace­ment methods, the benefits also can be greater.Not only can successfully placed implants lastlonger, look better, and function better thantraditional methods, they can improve the health,attitude, and lifestyle of the patient. Denta]implants may not be the treatment of choice f()rall patients, but each patient faced with the realityof tooth loss should be aware that dental-implantsurgery can be a safe, reliable option.

Dr. Pulver studied fL\ a clinical Fellow in the ()SSlYr

integration (Dental IrnjJlant) Unit, Department oJProsth­

odontics, at the University ({Toronto, Canada, under Dr.

George Zarb. This Unit was one of the more injluentialamters in the develojJrnent oldental imPlantology in North

A meriCfl. Dr. Pulver received his diPloma in (fral and

maxillofacial surgery from Northwestern University DlmtalSchool, Chicago, Illinois.

References

1. Adell R. Erikssoll II, Lekholm U. IIranemark ('[, Torstell'/' A lOll!!;'

term follow-up stlHly ()f ()ss('()intcgra(ed implanL'\ in the treatllll"lll ()f

totally edentlllolls jaws, Inl.f Oml Mnxillojilrin//mp/nnls. I ~~0;5::H 7-3,,9.

2. Priest (;F. Failure rates of restor;:ttioll for single tooth replacement.

Inl!l'm.ll/",donlio, I~96;~( I) :38-44.

3. Lazzara~. A prospective multiccnter study evaluating loading of

osseotitc implanl~ two months after placement: One-year results.}E,I""I;" IIn/li.llry, 1998; 10 (6) :280·289.

4. Summers R. A new cOIu:ept in maxilhuy implant surgery: The

osteotome tedlllique. Com/wwl Cnll F:dw:nnlt. 19~).1;XV(~): 15~-] GO.

S. DaviesJE.1\1edlanisms of end osseous integratioll. Int} Pmstlwdrm­lies. 1~98;11(5):391-401.

6. Parag-on Implant Company. A TedlIlologkal Report for Discerning

Dentisl.\ hy Gcrallt!1-Ngllick: Controversies, 111I1)laTltC<H1mxtiol1s and

Surf~lCes. Encino, CA: Paragon Implant Company; Novemher 1~)9R

Publication No, Ll43, 1',6,

The implantsurface

texture has

been the

center of

attention

recently asresearchers

explore the

theory thatincreased

roughness

may berelated to

increased

bone-to­

implantcontact.

""