Clinical evaluation alveolar ridge preservation with a beta-tricalcium phosphate socket graft

588 Compendium November | December 2009—Volume 30, Number 9

1Clinical Assistant Professor, Ashman Departments of Periodontology and Implant Dentistry and Department of Oral Surgery, New York

University College of Dentistry, New York, New York; Private Practice in Periodontics and Implant Dentistry, Scarsdale, New York2Private Practice in Periodontics and Implant Dentistry, Ra’ananah, Israel3Chairman, Department of Oral Implantology, Atlantic Coast Dental Research Clinic, Palm Beach, Florida; Private Practice, Delray

Beach, Florida4Private Practice in Periodontics and Implant Dentistry, Boca Raton, Florida5Senior Researcher, Department of Hard Tissue Research, Hard Tissue Research Laboratory, University of Minnesota, School of Dentistry,

Minneapolis, Minnesota6Professor and Director, Division of Oral and Maxillofacial Pathology and Director, Hard Tissue Research Laboratory, University of

Minnesota, School of Dentistry, Minneapolis, Minnesota

Continuing Education 2

Clinical Evaluation of Alveolar Ridge Preservation with a b-Tricalcium Phosphate Socket GraftRobert A. Horowitz, DDS;1 Ziv Mazor, DMD;2 Robert J. Miller, DDS;3 Jack Krauser, DMD;4

Hari S. Prasad, BS, MDT;5 and Michael D. Rohrer, DDS, MS6

Abstract: PURPOSE: To determine the efficacy of an alloplastic graft material, consisting of a pure-phase b-tricalcium

phosphate (b-TCP), in the preservation of ridge volume after tooth extraction and before dental implant placement. His-

tomorphometric analysis was completed on a few samples to determine the percentage of vital bone over a fixed healing

period. MATERIALS AND METHODS: Patients requiring tooth extraction and bone regeneration before implant placement

were included in this study. Measurements of alveolar width were made at the time of extraction and the time of implant

placement. The extraction sites were grafted with a pure-phase b-TCP and covered with a barrier. Approximately 6

months after surgery, the sites were reentered for implant placement. Cores were taken of the regenerated material for

histologic analysis, with a trephine used as the first bur in preparation for some of the osteotomies. Implants were placed

according to the manufacturers’ recommendations and loaded at the appropriate time. RESULTS: The b-TCP placed at the

time of grafting extraction sockets was well tolerated in all sites with all of the barriers used. There were no incidences of

postoperative infection or graft rejection. At the time of implant placement, much of the graft material had resorbed and

been converted to vital alveolar bone. The implant recipient sites were dense and supported placement of endosseous

dental implants that were fully stable. The width of the extraction sockets was preserved to 91% of the preoperative width.

CONCLUSIONS: Extraction socket grafting with the pure-phase b-TCP tested in this study and covered with either a re-

sorbable collagen or dense polytetrafluoroethylene barrier is a predictable method for preserving alveolar dimensions.

The graft material resorbs to a high percentage in the timeframe desired between extraction and dental implant place-

ment, as shown clinically, radiographically, and histologically. In addition, the regenerated material in the socket has

enough density to support implant placement with subsequent loading in the 4- to 6-month period used in this study.

www.compendiumlive.com Compendium 589

Patients present for tooth extraction for various rea-sons (eg, caries, periodontal disease).1 The dentalliterature describes loss of bone volume after den-

tal extractions of up to 50% within 6 months.2-4 The effectof bone loss is magnified when multiple teeth are extractedin the same area.5 Bone resorption will result in a loss ofsocket width in an apical and lingual direction. Socket col-lapse can prevent or significantly inhibit the placement ofdental implants in ideal, prosthetically driven positions.6

Severe loss of alveolar volume may necessitate ridge aug-mentation by block grafting and other extensive surgicalprocedures if dental implants are to be placed for the sup-port of a prosthesis.7

The purpose of this pilot study was to evaluate the clin-ical effects on alveolar ridge preservation after placement ofparticulate b-tricalcium phosphate (b-TCP) graft (Cera-sorb®, Curasan AG, www.curasan.de) placed at the time oftooth extraction.8-12 The graft material was mixed withblood from the site, grafted to fill the area to ideal contour,and covered with an occlusive barrier. Histologic evaluationof the regenerated material was performed from a core takenat 6-month reentry, concurrent with implant placement.Unlike other bone replacement graft materials currentlyused for this type of procedure,13-15 this graft material hasbeen shown to resorb fully and be replaced by vital alveolarbone in 6 to 10 months.16-19 In this study, this technique ofgraft and barrier placement led to 100% successful implantplacement, maintenance of 90% of buccolingual socketwidth, resorption of the graft material, and formation ofvital bone in the sockets.

MATERIALS AND METHODSThirty patients were selected on the basis of need for dentalextractions with bone preservation and/or augmentationin the socket before the placement of a dental implant.

These patients were cleared medically for oral surgicalprocedures. Preoperative clinical photographs and periapi-cal radiographs were taken. After administration of localanesthesia, full-thickness labial and lingual/palatal flapswere elevated. Minimal soft-tissue manipulation was per-formed to allow visualization of the entire alveolar crestsand debridement of fenestrations and/or dehiscence de-fects, if present. Elevation of each tooth or retained rootswas performed, using periotomes, luxatomes, proxima-tors, root forceps, and any other instruments and proce-dures as required to extract the tooth with minimal trauma(Figure 1). After extraction and thorough debridement ofthe socket by mechanical means, clinical photographswere taken. The sites then were grafted with a resorbableb-TCP of small particle size, 150 µm to 500 µm (Cera-sorb) (Figure 2). This material has been used and report-ed in the literature for almost 30 years as a viable bonegraft in orthopedic and other surgical specialties. In thisstudy, the granules of b-TCP were mixed thoroughly withblood from the surgical sites and the sockets filled to ideal

Robert A. Horowitz,

DDS

Ziv Mazor, DMD Robert J. Miller,

DDS

Jack Krauser, DMD Hari S. Prasad,

BS, MDT

Michael D. Rohrer,

DDS, MS

Learning ObjectivesAfter reading this article, the reader should be able to:

n understand the efficacy of an alloplastic graft materialthat consists of pure-phase b-tricalcium phosphate(b-TCP) in the preservation of ridge volume aftertooth extraction and before implant placement.

n perceive the differences between this study and previous findings by other researchers.

n discuss how this study validates the use of b-TCP as a useful bone replacement graft at the time oftooth extraction.

contours faciolingually and apicocoronally. The grafts andadjacent 3 mm of alveolar bone then were covered with re-sorbable collagen barriers (BioMend®, www.zimmerdental.com) (Figure 3). The flaps were repositioned and the areasclosed with an appropriate number and type of sutures.No attempts were made to obtain primary closure over theexposed barriers. Postoperative radiographs and clinical

photographs were taken. Subsequently, sutures were re-moved at 1 to 2 weeks.

The grafted sites were followed clinically and radi-ographically throughout the healing period. Healing of theresidual crestal defects (if present) also was followed. Atapproximately 6 months, the patients returned for graftanalysis and placement of implants. Clinical photographsand radiographs were taken preoperatively. After adminis-tration of local anesthesia and minimal flap elevation,measurements of alveolar ridge width were repeated tocompare with the preoperative alveolar dimensions (Fig-ure 4). The coronal portions of the regenerated sites wereevaluated for the presence of residual graft material. Prepa-ration of the osteotomies was initiated with a bone tre-phine to sample the coronal 5 mm to 7 mm of socket heal-ing (Figure 5). The placement of appropriately sized dentalimplants was performed according to the manufacturer’srecommendations, and the flaps were sutured to facilitateboth soft- and hard-tissue healing.



Figure 1 Occlusal view after extraction of tooth No. 27

using Piezosurgery® (Piezosurgery Inc, www.piezosurgery.com)

and thin-bladed elevators.

Figure 2 The extraction socket was grafted with a mixture

of pure-phase b-TCP and heme from the surgical site.

Figure 3 A resorbable collagen barrier was placed over the

graft material for particle containment and guided bone

regenerative principles.

Figure 4 Occlusal view of the healed bony ridge, taken at

the time of implant placement.

Figure 5 Occlusal view of the osteotomy site after retrieval

of a core of regenerated material.



HISTOLOGIC PREPARATION AND HISTOMORPHOMETRYBone cores were harvested from the surgical sites at the timeof dental implant placement. The trephines containing thebone were fixed in 10% neutral buffered formalin. On re-ceipt in the Hard Tissue Research Laboratory at the Uni-versity of Minnesota School of Dentistry, the specimenswere dehydrated immediately with a graded series of alco-hols for 9 days. After dehydration, the specimens were infil-trated with a light-curing embedding resin (Technovit 7200VLC, Heraeus Kulzer Technical Division, www.heraeus-kulzer-us.com). After 20 days of infiltration with constantshaking at normal atmospheric pressure, the specimens wereembedded and polymerized by 450-nm light, with the temper-ature of the specimens never exceeding 40°C. The specimensthen were prepared with the cutting/grinding method ofDonath.20,21 The specimens were cut to a thickness of 150 µmon an EXAKT cutting/grinding system (EXAKT Techno-logies, Inc, www.exaktusa.com). Next, the slides were polished

to a thickness of 45 µm, using the EXAKT microgrindingsystem followed by alumina polishing paste and stained withStevenel’s Blue and van Gieson’s picrofuchsin. After histo-logic preparation, the cores were evaluated morphometri-cally. All the cores were digitized at the same magnificationusing an Axiolab microscope (Carl Zeiss MicroImaging Inc,www.zeiss.com) and a Coolpix® 4500 digital camera (NikonAmericas Inc, www.nikonusa.com). Histomorphometric meas-urements were completed using a combination of Adobe®Photoshop® (Adobe Systems, Inc, www.adobe.com) and theNational Institutes of Health’s image program (available tothe public at http://rsb.info.nih.gov/nih-image). At least twoslides of each core were evaluated. Parameters evaluated weretotal area of the core, percentage of new bone formation, andpercentage of residual graft material.

At the appropriate time after implant placement, re-storative procedures were performed. The implants wererestored with fixed ceramometal restorations to return thepatients to ideal form and function (Figure 6 and Figure 7).Alveolar crestal heights were followed radiographicallyfrom the times of extraction through placement of the finalrestorations to assist in determination of stability of thecrestal attachment apparatuses.

RESULTSIn the 30 patients who entered this study, 21 sites havereceived dental implants as of this writing. The healing ofall sites grafted at the time of extraction with b-TCP wasuneventful. In five of the sites where there was no primaryclosure over a minimally exposed portion of the mem-brane, reepithelialization occurred within the first 2 weekspostoperatively.

The sites that were reentered for dental implant place-ment demonstrated excellent preservation of buccolingualalveolar ridge width. The initial socket widths ranged from8 mm to 12 mm, with an average of 9.6 mm. Average lossof buccolingual width for the period studied was 12.4%.Though there were a smaller number of sites at which thegrafts were separated by particle size, better ridge widthmaintenance was obtained with the larger (500 µm to1000 µm) particle sizes as shown by 92% preservation ofthe preextraction width (Table 1).

Coronally, in a number of cases, some residual graftparticles were visible at the time of osteotomy preparation,which did not affect either the surgical procedure or theinitial stability of the dental implant. The osteotomies

Figure 6 Buccal view of the final restoration on the implant

inserted in site No. 27. Note the excellent maintenance of

the soft-tissue contours.

Figure 7 Occlusal view 18 months after the final restoration

was inserted. Note the amount of preservation of hard and

soft tissues.



were prepared and implants inserted in the surgical sitesaccording to the manufacturers’ recommendations. Mar-ginal gingival tissues were well supported to enable func-tional and esthetic restoration of the implants with fixedprostheses approximately 3 months later.

Histologically, in this early period, there was evidenceof vital bone ingrowth into the extraction sockets graftedwith this pure-phase b-TCP (Figure 8 through Figure 11).New bone formation was present in intimate contact with

the surface of the graft particles. Some residual graft parti-cles were present in all specimens investigated. Varyingdegrees of resorption and remodeling were noted in each ofthe specimens.

DISCUSSIONCharacteristics for ideal bone replacement graft materialsinclude safety, efficacy, and the ability for the graft mate-rial to be replaced by vital alveolar bone. The b-TCP graft

Table 1: Ridge Widths

Buccolingual Buccolingual BuccolingualNo. of No. of Bone Implant Width Change Change

Pat No. Age Cerasorb Sites Months Quality* Stability† (mm) (mm) %

42 53 150-500 1 8.2 1.0 1 11 0.0 0.00

8 31 150-500 1 12.9 2.0 1 10 0.5 5.00

10 54 150-500 1 9.2 2.0 1 10 0.5 5.00

28 54 150-500 1 8.2 2.0 1 10 0.5 5.00

13 58 150-500 1 10.1 3.0 1 10 1.0 10.00

27 71 150-500 1 7.0 2.0 1 10 1.0 10.00

33 82 150-500 1 4.5 3.0 1 8 1.0 12.50

43 54 150-500 1 7.8 2.0 1 8 1.0 12.50

41 68 150-500 2 9.0 2.0 2 10 2.0 20.00

2 75 150-500 1 8.0 2.0 1 9 2.0 22.00

20 45 150-500 2 7.5 3.0 1 9 2.0 22.22

26 78 150-500 1 11.5 2.5 1 9 2.0 22.22

45 64 150-500 1 8.3 1.0 1 10 3.0 30.00

3 53 500-1000 1 4.6 1.0 1 8 0.0 0.00

17 70 500-1000 1 7.0 3.0 1 9 0.0 0.00

22 49 500-1000 2 8.0 2.5 1 10 0.0 0.00

24 45 500-1000 1 6.0 2.0 1 11 1.0 8.00

1 68 500-1000 1 3.7 2.0 1 12 1.0 8.33

23 54 500-1000 1 6.0 3.0 1 9 1.0 11.00

25 56 500–1000 1 6.0 3.0 1 11 2.0 18.18

12 63 500-1000 1 9.5 3.0 4 8 1.5 18.75

Averages All sites 9.6190476 1.0952381 12.41

150-500 9.5384615 1.2692308 13.57

500-1000 9.7500000 0.8125000 8.03

*Quality: 1 = dense, 2 = medium, 3 = soft, 4 = too soft for implant placement.†Stability: 1 = torqued out motor, 2 = fully stable, 3 = slight mobility but no rotational movement, 4 = implant spins in site.



material used in this study is a purely synthetic materialfabricated to exact chemical specifications.22 Porosity (of theb-TCP materials), both macroscopic and microscopic, is de-signed to maximize blood clot stability during early healing.The material has no organic components and, therefore, nochance of antigenicity or allergic reactions. As the material issynthesized in the laboratory, any possible infectivity is re-moved. There have been recent concerns regarding possibledisease transmission from allografts and xenografts. Using an

alloplastic regenerative material prevents this possibility, elim-inating the surgeon’s as well as the patient’s apprehension.Chemically, the graft has a similar composition to a salt. Be-cause of the chemical composition and high purity of thematerial, no cytotoxic compounds are released during break-down and resorption of this graft material.22,23 Comparedwith autogenous bone grafting, this synthetic graft has un-limited availability without the increased potential for post-operative morbidity from the harvesting procedure.

Figure 8 Very high-power image of immature bone surround-

ing particles of Cerasorb. At the periphery of the particles,

the resorption of the Cerasorb and the blending into the sur-

rounding vital bone structure is visible (original magnification

x200, Stevenel’s Blue and van Gieson’s picrofuchsin).

Figure 9 High-power image shows numerous particles of

Cerasorb with new bone formation. The bone trabeculae are

forming in an area in which Cerasorb appears concomitantly

to be resorbing. Green-staining osteoid is seen associated

with the Cerasorb particles on the right. This is what will

become bone (original magnification x100, Stevenel’s Blue

and van Gieson’s picrofuchsin).

Figure 10 Low-power image shows a core of very dense

vital bone trabeculae forming a very good cancellous bone

pattern. Some particles of Cerasorb remain without surrounding

bone (original magnification x20, Stevenel’s Blue and van

Gieson’s picrofuchsin).

Figure 11 High-power image shows bridging among particles

of Cerasorb by newly formed bone trabeculae. It also shows

that this new bone formation has occurred around particles

of Cerasorb. On the upper right surface of the large particle

of Cerasorb in the upper portion of the image, green-staining

osteoid is forming. This is the manner in which the new bone

is formed around the Cerasorb (original magnification x100,

Stevenel’s Blue and van Gieson’s picrofuchsin).

In previous papers on dental extraction therapy with orwithout immediate socket implants, site collapse in a buc-colingual dimension was ≥ 50% for a 6-month period.Studies have demonstrated preservation of alveolar dimen-sions after extraction socket grafting.24-26 These studiesshowed no treatment of the socket resulted in a collapse ofthe alveolus by 29% and grafting the socket at the time ofextraction resulted in bone loss of only 13%.24 The averageloss of alveolar width in the grafted sites in this study was12%. Numerous papers state that one of the reasons toplace an immediate socket implant is to preserve the alveo-lar ridge width. That statement is not borne out consis-tently in the conclusions of the authors. One recent paper,in which reentry was performed at the time of dentalimplant uncovering, offers an alternative conclusion. Inthat paper, implants were placed after extraction of single-rooted teeth. After averaging the ridge width changes, itwas noted that there was a 35.2% loss of bone volume inthe buccolingual dimension.25 Similar evidence of socketcollapse after placement of immediate socket dental im-plants questions the use of this technique to preserve al-veolar bone volume.26 The results of this current studyclearly demonstrate a significantly better maintenance ofalveolar ridge dimension than the placement of an imme-diate socket dental implant with no grafting (Figure 12through Figure 14).

Other dental research has demonstrated vital bone fillin extraction sockets with other techniques and materials.One combination of graft materials that has been researchedwidely for more than 10 years is demineralized freeze-driedbone allograft with calcium sulfate.27-29 While the tech-nique has proven effective, human and some animal-derivedbone graft products are not able to be used in a number ofcountries. In certain instances, the placement of a densePTFE has been shown to improve vital bone formationwhen placed over an extraction socket or other surgical de-fects.30-32 However, sufficient proximal and facial or lingualbone is required for support and stabilization of the barrierfor the required period.

The material researched in this paper is a pure-phase b-TCP, which disintegrates eventually and will fully convertto vital alveolar bone. Other bone graft materials that areradiopaque at the time of insertion are resorbed minimally,if at all, during this period,33 giving the surgeon no clueas to the amount of biologic healing that is occurring. Incontrast, resorbable grafting materials change radiopacity

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IN OFFICE TREATMENTIN OFFICE TREATMENT

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November | December 2009—Volume 30, Number 9

to appear like normal trabeculated bone as they heal. Anadvantage of b-TCP is that it will break down clinically,histologically, and radiographically (Figure 15 throughFigure 17), providing the surgeon with an indication of theappropriate time to place a dental implant in the graftedsite. The sites grafted with b-TCP exhibited a decreasedamount of bone loss as compared to nongrafted sites. Thetreated sites in this study lost, on average, only 12% of thebuccolingual width of the original socket dimension. Thepresent results validate the use of this b-TCP for preserva-tion of extraction socket dimensions. The alveolar mainte-nance provided by this material is comparable with ridgepreservation, using other materials discussed in the litera-ture.34 One recent socket treatment study by Iasella et alcompared no treatment after extraction to grafting thesocket with freeze-dried bone allograft and covering the sitewith a collagen barrier.24 In the Iasella et al study, the siteswhere no socket preservation therapy was performed lost,on average, 2.6 mm of an initial 9.1-mm ridge width. Thegraft- and barrier-treated sites lost only 1.2 mm of the ini-tial 9.2-mm ridge width. In this study, the initial alveolarwidth was 9.4 mm and the sites lost 1.42 mm on average.The slight decrease of 9.3% in buccolingual dimension inthis study compared favorably to the loss of 29% in the un-treated sites and the 13% loss in the graft and barrier treat-ed sites 6 months after extraction in that study. Anotherstudy by the same research group compared two types ofgraft- and barrier-protection socket therapies.35 All socketstreated by the two different methods of augmentation losthorizontal ridge width (6% for one group and 5% for theother) but significantly less than untreated sockets.

The results of preservation of alveolar volume afterextraction by bone grafting are more favorable than the sitecollapse seen after placement of immediate socket im-plants. One study showed that even after placement ofimmediate socket implants, there was a buccolingual col-lapse of alveolar width of 56% during the 4-month healingperiod.36 This negates one of the purported advantages ofplacing immediate socket dental implants to preserve alve-olar ridge dimensions. In their study, Schropp et al per-formed uncovering surgery at the second stage that enabledthe investigators to visualize the alveolar crest.37 Althoughthe alveolar defects were filled with autogenous bone atthe time of implant placement, minimal healing resulted.A total of 25% of the initial dehiscence defects healedfully, and approximately 50% of the height and/or width

defects healed fully at the visual level. Autogenous bonedid not satisfy the criteria of visually filling the gap andbecoming bone, even at the macroscopic level, leaving nopossibility of osseointegration in that portion of the im-plant. Another research paper demonstrated similar con-cerns with osseointegration in alveolar ridges augmented

Horowitz et al.


Figure 12 A patient who had tooth No. 2 extracted using

Piezosurgery, periotomes, thin-bladed elevators, and small-

beaked forceps, enabling preservation of all bony peaks.

Figure 13 After debridement of the socket, a mixture of

pure-phase b-TCP and heme from the surgical site was covered

with a dense polytetrafluoroethylene (PTFE) barrier.

Figure 14 At the time of the 6-month reentry, the site appeared

healed. Full ridge height preservation and graft resorption with

bony replacement were confirmed radiographically.

with bovine bone mineral. In another study, edentulousportions of the alveolar ridge in dogs were augmented withbovine bone mineral and allowed to heal.38 Implants wereplaced 3 months later, followed by abutment connectionin an additional 3 months. After allowing the soft tissues toheal for 4 months, the animals were sacrificed. Histologicevaluation in this study revealed alveolar defects between

the implants and the nonaugmented portion of the ridges.There was minimal-to-no osseous incorporation of the bovinebone mineral into the alveolar bone during the healing periodand no evidence of osseointegration at the alveolar crest in thegrafted sites. If bone augmentation were performed with a fullyresorbable material that was replaced by vital, alveolar bone,there should be more vital bone and bone-to-implant contactat the crest. This could prevent bone and/or soft-tissue lossaround a prosthetically loaded implant.

The results of this clinical study validate the use of thisb-TCP for preservation of extraction socket dimensions.The alveolar maintenance provided by this material iscomparable to ridge preservation, using other previouslyresearched materials and superior to the bone preservationfrom conventional immediate socket dental implant thera-py. In this current study, the loss of buccolingual widthaveraged 12% of the original alveolar width. For the casesin which larger particle sizes of pure-phase b-TCP wereused, the site width was maintained at 92% of the originalsocket dimensions. The ability to preserve this volume ofalveolar bone and soft tissue after tooth extraction enablesthe surgeon to place dental implants in these sites ideally.In addition the complete resorption of b-TCP over time,as shown in the histologic specimen analyzed in this studyand in dental, orthopedic, and veterinary research, hasmany benefits.39,40 In one recent study, a fully resorbableb-TCP mixed with bone marrow-aspirated stem cells provedsuperior to iliac crest grafting for bone formation in an areathat normally does not form bone.41 A current publishedminipig study showed two outcomes essential for implantdentistry.42 Critical-size defects were made in the tibia ofminipigs and filled with b-TCP and implants stabilized inthe sites. After healing for 5 months, the b-TCP sites showedno histologic presence of inflammation and 70% resorp-tion of the graft materials with vital bone replacement. Alater period histologic specimen showed osseointegrationwith 95% replacement of the graft with vital bone. Use ofa resorbable bone-replacement graft material eliminatesthe possibility of delayed alveolar socket healing, preventsresidual graft particles from interfering with osseointegra-tion, and allows complete fill of the socket (or other treatedsite) with vital alveolar bone.

CONCLUSIONSClinically, alveolar ridge width was maintained to a veryhigh degree after extraction socket grafting with this b-TCP.



Figure 15 After extraction, the outline of the socket is

visualized radiographically.

Figure 16 Radiograph showing the site after it was filled

with the resorbable bone graft material and covered with

the PTFE barrier.

Figure 17 At the time of reentry, the pure-phase b-TCP particles

appeared clinically to have resorbed, preserved the full ridge

width, and been replaced by bone.



As opposed to previous investigations that had shown theloss of 40% to 60% of the buccolingual width of theextraction socket for cases in which no grafting materialwas used, this study demonstrated almost 90% of the ridgewidth was maintained on average. Further investigationswill be conducted to determine the timeframe for resorp-tion and vital bone ingrowth into the treated sockets. Asvarious particle shapes and sizes may have different resorp-tion characteristics, clinical and histologic evaluation willbe performed on these materials, as well. An ideal graftingmaterial for this indication should maintain alveolar sock-et width and have the ability to be resorbed and replacedby new bone formation. It is clear that the material investi-gated in this study meets these criteria. The present clinicalstudy validates the use of b-TCP as a useful bone replace-ment graft at the time of tooth extraction. Clinical meas-urements showed preservation of alveolar width, and his-tologic analysis demonstrated both resorption of the graftmaterial and conversion to vital alveolar bone. These char-acteristics make this graft material ideal for use after toothextraction in conventional and implant dentistry.

DISCLOSURESupport for the histologic evaluation, analyses, and clinicalmaterials was provided by Curasan AG. Dr. Mazor andDr. Horowitz have received honorariums from Curasan AG.

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Continuing Education 2 Quiz 2

Please see tester form on page 606.

1. Histologic evaluation of the regenerated material wasperformed:

a. chairside by the authors.b. using chips left on the implant drill.c. from a core taken at 6-month reentry, concurrent

with implant placement.d. using a confocal electron microscope.

2. In this study, this technique of graft and barrierplacement led to what percent successful implantplacement?

a. 100%b. 98%c. 90%d. 84%

3. In this study, the granules of b-TCP were mixed thoroughly with what and the sockets filled to idealcontours faciolingually and apicocoronally?

a. sterile salineb. blood from the surgical sitesc. salivad. polymorphogenic cells from the adjacent sulcus

4. Porosity (of the b-TCP material), both macroscopicand microscopic, is designed to:

a. allow direct contact of the implant with thebone.

b. allow direct contact of the implant with thegraft material.

c. maximize blood clot stability during early healing.d. maximize the amount of torque that can be

applied to an implant abutment.

5. Numerous papers state that one of the reasons toplace an immediate socket implant is to:

a. reduce the amount of drilling of alveolar bone.b. reduce the amount of drilling of trabecular bone.c. preserve the alveolar ridge width.d. increase homeostasis.

6. In the Iasella et al study, the sites where no socketpreservation therapy was performed lost, on average,how many mm of an initial 9.1-mm ridge width?

a. 1.6 mmb. 2.6 mmc. 3.6 mmd. 4.6 mm

7. One study showed that even after placement ofimmediate socket implants, there was a buccolingualcollapse of alveolar width of what percent during the4-month healing period?

a. 56%b. 66%c. 76%d. 86%

8. The results of this clinical study validate the use ofwhat for preservation of extraction socket dimensions?

a. plasma-rich proteinb. calcium permanganatec. this b-TCPd. biologic barrier

9. This study demonstrated almost what percent of theridge width was maintained on average?

a. 60%b. 70%c. 80%d. 90%

10. An ideal grafting material for this indication should: a. maintain alveolar socket width. b. have the ability to be resorbed. c. have the ability to be replaced by new bone

formation.d. all of the above

This article provides 2 hours of CE credit from AEGIS Communications. Record your answers on the enclosed answer sheet orsubmit them on a separate sheet of paper. You may also phone your answers in to (888) 596-4605 or fax them to (703) 404-1801or log on to www.compendiumlive.com and click on “Continuing Education.” Be sure to include your name, address, telephonenumber, and last 4 digits of your Social Security number.

Documents

Clinical evaluation alveolar ridge preservation with a beta-tricalcium phosphate socket graft