Zirconia Removable Telescopic Dentures

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Zirconia Removable Telescopic Dentures Retained on Teeth or Implants for Maxilla Rehabilitation. Three-Year Observation of Three Cases Gregory-George Zafiropoulos, DDS, Dr Dent, Dr Habil 1 * Jochen Rebbe, DT 2 Ulrich Thielen, MDT 2 Giorgio Deli, DDS, MD 3 Christian Beaumont, DDS, Dr Med Dent 2 Oliver Hoffmann, DDS, MSc, Dr Med Dent 4 This report addresses maxillary restoration with removable telescopic crown-retained palatal free dentures. One patient with 7 natural teeth (PERIO), a second patient with 6 dental implants (IMPL), and a third patient with 2 natural teeth and 4 dental implants (IMPL-PERIO) were treated. Zirconia copings for natural teeth and individual zirconia implant abutments were fabricated in CAD/CAM and used as primary crowns. Electroformed gold copings were used as secondary telescopes. All maxilla supraconstructions were fabricated with zirconia and CAD/CAM. Patients were monitored during a 3-year period; all teeth and implants survived, and no biological or mechanical complications occurred. The peri-implant and periodontal conditions were healthy. While recognizing the limitations of this report, results showed that fabricating removable zirconia structures by means of CAD/CAM can yield highly functional and esthetic results. Galvanoforming technology is the preferable means of fabricating secondary crowns. The combination of these techniques and materials results in a prosthetic reconstruction of high quality, good fit, and biocompatibility. Long-term studies of large populations are necessary to investigate the clinical properties of the material utilized in this type of construction. Key Words: dental implants, zirconia, telescopic crowns, removable dentures, implant abutments, electroformed crowns INTRODUCTION A number of recent studies rec- ommend the use of removable prostheses with telescopic at- tachments fastened to natural teeth and/or implants for pros- thetic restoration. 1–4 This restoration tech- 1 Department of Operative Dentistry and Periodontol- ogy, University of Mainz, Germany, and Blaues Haus Dental Center, Duesseldorf, Germany. 2 Herrmann Dental Studio, Duesseldorf, Germany. 3 Division of Periodontology, Catholic University of Sacro Cuore, Rome, Italy. 4 Department of Periodontics, School of Dentistry, Loma Linda University, Calif. * Corresponding author, e-mail: zafiropoulos@blaues- haus-duesseldorf.de DOI: 10.1563/AAID-JOI-D-09-00065 CLINICAL Journal of Oral Implantology 455

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Transcript of Zirconia Removable Telescopic Dentures

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Zirconia Removable Telescopic DenturesRetained on Teeth or Implants forMaxilla Rehabilitation. Three-YearObservation of Three CasesGregory-George Zafiropoulos, DDS, Dr Dent, Dr Habil1*Jochen Rebbe, DT2

Ulrich Thielen, MDT2

Giorgio Deli, DDS, MD3

Christian Beaumont, DDS, Dr Med Dent2

Oliver Hoffmann, DDS, MSc, Dr Med Dent4

This report addresses maxillary restoration with removable telescopic crown-retained palatal

free dentures. One patient with 7 natural teeth (PERIO), a second patient with 6 dental

implants (IMPL), and a third patient with 2 natural teeth and 4 dental implants (IMPL-PERIO)

were treated. Zirconia copings for natural teeth and individual zirconia implant abutments

were fabricated in CAD/CAM and used as primary crowns. Electroformed gold copings were

used as secondary telescopes. All maxilla supraconstructions were fabricated with zirconia

and CAD/CAM. Patients were monitored during a 3-year period; all teeth and implants

survived, and no biological or mechanical complications occurred. The peri-implant and

periodontal conditions were healthy. While recognizing the limitations of this report, results

showed that fabricating removable zirconia structures by means of CAD/CAM can yield

highly functional and esthetic results. Galvanoforming technology is the preferable means of

fabricating secondary crowns. The combination of these techniques and materials results in a

prosthetic reconstruction of high quality, good fit, and biocompatibility. Long-term studies

of large populations are necessary to investigate the clinical properties of the material

utilized in this type of construction.

Key Words: dental implants, zirconia, telescopic crowns, removable dentures, implantabutments, electroformed crowns

INTRODUCTION

Anumber of recent studies rec-

ommend the use of removable

prostheses with telescopic at-

tachments fastened to natural

teeth and/or implants for pros-

thetic restoration.1–4 This restoration tech-

1 Department of Operative Dentistry and Periodontol-ogy, University of Mainz, Germany, and Blaues HausDental Center, Duesseldorf, Germany.2 Herrmann Dental Studio, Duesseldorf, Germany.3 Division of Periodontology, Catholic University ofSacro Cuore, Rome, Italy.4 Department of Periodontics, School of Dentistry,Loma Linda University, Calif.* Corresponding author, e-mail: [email protected]: 10.1563/AAID-JOI-D-09-00065

CLINICAL

Journal of Oral Implantology 455

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nique is preferred in Central Europe for

partially edentulous and periodontologically

injured dentition. It has existed as a broadly

accepted and scientifically recognized ap-

proach within dentistry and predates the

establishment of oral implantology.5

In a current publication, our team also

discusses the advantages of telescope-borne

structures.6 Briefly, these advantages are: (1)

the distribution of force on the abutment; (2)

the provision of a foundation for effective

oral hygiene, and maintenance of periodon-

tal health; (3) the arrangement of teeth in

the desired position; (4) circumvention of

several augmentative measures in the soft

and hard tissues for esthetic reasons; (5)

achievement of favorable esthetics, even

with there is substantial recession of the

periodontal tissue or severe atrophy of the

jaw; (6) creation of a gum-free structure in

the maxilla; (7) longevity of the structure (eg,

veneers can be reapplied at any time, and

the structure remains in place even if one of

the abutment teeth or implants is lost); and (8)

avoidance of augmentative measures if gingi-

val and/or peri-implant recessions arise before

the construction is fabricated or while it is

being worn since recessions can be covered by

the lip shield.

The disadvantages of this type of con-

struction are: (1) high costs and technical

requirements; (2) the need for the dental

technician to master the individual steps for

creating such constructions; and (3) any

psychological burden experienced by the

patient provided with a removable construc-

tion.

Today, patients with periodontally re-

duced dentition and partially or fully eden-

tulous patients who are to be provided with

implants have become sensitized to esthetic

appearance in addition to the maintenance

of oral health. The introduction of zirconium

oxide (zirconia) as a biocompatible material

in restorative dentistry, the light weight of

the structures made with this material, the

development of new ceramics and compos-

ites for veneers, and the ongoing develop-

ment of CAD/CAM technology were the

factors that led us to manufacture tele-

scope-borne zirconia constructions.

MATERIALS AND METHODS

Patients

Three nonsmoking patients (1 female and 2

male) were selected for this retrospective

study. In 2005, all 3 patients presented for

treatment of advanced chronic periodonti-

tis7 in the office of one of the authors (G.G.Z.,

Duesseldorf, Germany). After multiple extrac-

tions over the previous 2 years, the first

patient (PERIO, female, 58 years old) had 7

natural maxillary teeth that were retained by

periodontal treatment. This patient rejected

the placement of an implant.

The maxillary teeth of the second patient

(IMPL, male, 65 years old) had been extract-

ed 4 years earlier, with the exception of teeth

number 2 and 15. These 2 teeth possessed

class II mobility but no defect in the region

of the furcation. They were integrated into

the existing restoration (telescopic-crown

overdenture). This patient requested an

implant-supported restoration of the maxilla.

The third patient (IMPL-PERIO, male,

60 years old) presented after multiple

extractions of maxillary teeth due to ad-

vanced periodontal disease. Teeth number 6

and 11 were present, with class II mobility.

The patient requested a palate-free, implant-

supported restoration of the maxilla and

periodontal treatment of the remaining

dentition.

All existing mandibular teeth of the 3

patients were preserved, and a partial

removable denture was not necessary for

mandible restoration in any of the patients.

Initial treatment

The full-mouth initial periodontal treatment

involved oral hygiene instructions, supragin-

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gival tooth cleaning and polishing, and

subgingival scaling and root planing.

Surgical and implant treatment

In all 3 cases, subgingival scaling and root

planing was followed by access flap surgery.8

Six cylindrical screw-type implants (RN,

length 10 mm, 04.1 mm, SLA, Straumann,

Waldenburg, Switzerland) were placed in

the maxilla of the IMPL patient and 4

cylindrical screw-type implants (Straumann)

were placed in the maxilla of the IMPL-PERIO

patient, using a 1-stage surgical approach.

Following full-thickness flap elevation, oste-

otomy preparation was performed at 875

rpm, and implants were manually placed

at a torque of 35 Ncm (046.119/046.049

Straumann) in positions number 4, 5, 6, 11,

12, and 13 and in positions number 4, 5, 12,

and 13 (IMPL and IMPL-PERIO patients,

respectively).

Postoperative care

Both IMPL and IMPL-PERIO patients were

prescribed a systemic antibiotic (clindamycin,

Ratiopharm, Ulm-Donautal, Germany; 600 mg/d)

to be taken once a day for 6 days and the

oral analgesic diclofenac (Voltaren, Novartis

Pharma, Nuremberg, Germany; 100 mg/d for

4 days), starting 1 day prior to surgery and

implant placement. All 3 patients were

instructed to rinse twice daily with 0.1%

chlorhexidine (Chlorhexamed Fluid, Glaxo-

SmithKline, Buehl, Germany) for 3 weeks,

also starting 1 day before periodontal sur-

gery and implant placement.

Sutures were removed 8 days postoper-

atively. Follow-up appointments were sched-

uled twice a month during the first 2 months

after surgery, and once a month thereafter

until loading.

Temporaries

The IMPL patient was provided with a

provisional full denture for the maxilla. Teeth

number 2 and 15, which were given

telescopic crowns, were preserved to pro-

vide the denture with greater retention. The

PERIO and IMPL-PERIO patients were given

temporary removable partial prostheses.

Rehabilitation

Four months after implant placement (IMPL

and IMPL-PERIO patients) and 3 months after

periodontal treatment (PERIO patient), max-

illae were restored with telescopic crown-

retained palate-free removable dentures.

Impressions were taken with individual

acrylic trays (the open-tray impression tech-

nique was used for implant cases) using a

polyether impression material (Impregum

Penta Soft, 3M ESPE, Seefeld, Germany).

Casts were mounted on a semi-adjustable

articulator (SAM 2P, SAM Praezisionstechnik,

Gauting, Germany), using the face-bow

technique and check-bite registration.

A wax-up was created and used as an

orientation tool for the patient and surgeon

as well as for further planning of rehabilita-

tion. After the esthetic and functional try-in

with the wax-up, a matrix of C-silicone

(Zetalabor, Zhermack SpA, Badia Polesine,

Italy) was manufactured. The direction of

insertion and planned tooth position were

determined by this silicone key (Figure 1A).

In addition, it can be used to create a mock-

up.

Primary telescopic crowns

Implants

Customizable abutments were used (RN

synOcta 048.642, Straumann) to fabricate

the individual zirconia implant abutments.

These abutments consist of a prefabricated

cast-on base and a residue-free burn-out

plastic channel (Figure 1a). The plastic chan-

nels of the 6 abutments were patterned with

resin (Pattern Resin, GC Dental Products

Corp, Leuven, Belgium) (Figure 1b). The

patterns were scanned and milled in a

CAD/CAM (M4820, I-MES, Eiterfeld, Ger-

many). After scanning, the zirconia implant

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abutments were fixed on the abutment cast-

on base using a self-curing compomer

cement (AGC Cem, Wieland Dental, Pforz-

heim, Germany) (Figure 1c). Subsequently,

the zirconia implant abutments were ground,

polished and sintered, and served as primary

telescopes with a minimum thickness of

0.6 mm (Figure 1d through f).

Teeth

After the models were created, the tooth

abutments were scanned using construction

software (ZENO CAD, in CAD/CAM, Wieland

Dental) and a scanner (Dental Designer,

3shape, Copenhagen, Denmark), and the

primary telescopes were fabricated and

milled as zirconia copings (ZENO Discs,

Wieland Dental) (Figure 2a and b). An

insertion key of resin (Pattern Resin, GC

Dental Products Corp) and a metal wire

0.3 mm in diameter were manufactured and

used for an oral try-in of the primary

telescope on the abutment to determine

precision of fit and direction of insertion

(Figure 2c).

Subsequently, a new impression was

made over the primary telescope and

insertion key using a polyether impression

material (Impregum Penta Soft, 3M ESPE,

Seefeld, Germany). This was used to fabricate

a new working model of cast plaster

(Figure 2d and e).

Secondary Telescopic Crowns

As secondary telescopes, electroformed pure

gold copings with a thickness of 0.25 mm were

fabricated (AGC Galvanogold, Au . 99.9%,

Wieland Dental) (Figure 3a through c).9,10

Supraconstructions

The superstructure was created by using

construction software (ZENO CAD in CAD/

CAM, Wieland Dental) and a scanner (Dental

Designer, 3shape, Copenhagen, Denmark)

(Figure 3d). Subsequently, a milling program

(ZENO CAM, Wieland Dental) was used to

create a plastic mock-up (ZENO-PMMA, Wie-

land Dental) on a milling machine (I-MES,

Eiterfeld, Germany). The mock-up was then

tried in to check occlusion and the overall

shape of the construction (Figure 3e). After

the try-in and necessary corrections, the

altered mock-up was scanned again. The

zirconia framework (ZENO Discs, Wieland

FIGURE 1. (a) Creation of implant abutments using C-silicon matrix as orientation. (b) Wax-up of animplant abutment before scanning. (c) Zirconia implant abutments were fixed on the synOcta titanparts. (d) Zirconia implant abutment was ground, polished, and sintered. (e) Finished zirconia implantabutment. (f) Fit-in of the zirconia implant abutments. IMPL patient: region number 2 and 15 naturalteeth with primary telescopes of the ‘‘old’’ restoration.

Zirconia Telescopic Dentures for Maxilla Rehabilitation

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Dental) was then milled using a CAD/CAM

system (M4820, I-MES, Eiterfeld, Germany)

and sintered in a sintering furnace (ZENO

Fire, Wieland Dental) for 14 hours at 1500uC(Figure 4a). To veneer the implant-retained

supraconstruction, a high-fusing microce-

ramic (Vintage ZR, Shofu Dental, Ratingen,

Germany) was used. To veneer the natural

tooth-retained supraconstruction, a lightly

cured indirect ceramic polymer (Ceramage,

Shofu Dental) and a bonding system (Bond I

and II, Shofu Dental) were used (Figure 4B

through E). The zirconia superstructure

possessed a wall thickness of 0.6 mm,

occlusal distance of 1.5 mm and 3 3 3 mm

proximal connecting elements.

FIGURE 2. (a) Zirconia copings were CAD/CAM created. (b) Finished zirconia coping. (c and d) Fit-in of thezirconia copings. (e) New working model fabricated after fit-in of the copings.

FIGURE 3. (a) Fabrication of electroformed gold copings. (b) IMPL patient, zirconia implant abutments asprimary telescopes with secondary gold copings as secondary telescopes; natural teeth number 2 and15 with primary telescopes from the old restoration. (c) Supraconstruction was created in CAD/CAM.(d) IMPL patient mock-up. (e) PERIO patient mock-up.

Zafiropoulos et al

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After veneering, the gold copings were

fixed in the supraconstruction using a self-

curing copolymer cement (AGC Cem, Wie-

land Dental) (Figure 4f ). After fitting the

denture, the jaw relation was rerecorded

using a central tracing device and a face-

bow, remounted to a semi-adjustable artic-

ulator (SAM 2P, SAM Praezisionstechnik).

Final adjustments to the occlusion were

made (Figure 5a through d).

The zirconia implant abutments were

manually placed at a torque of 35 Ncm.

The screw opening of the abutment was

filled with a single-component light-cured

resin (Fermit, Ivoclar Vivadent, Schaan, Liech-

tenstein) (Figure 5e).

FIGURE 4. (a) CAD/CAM fabricated zirconia supraconstruction. (b and c) Finished/veneered supra-construction for PERIO patient. (d and e) Finished/veneered supraconstruction for IMPL patient.(f) Gold copings fixed in the supraconstruction.

FIGURE 5. (a and b) Attachment system with natural tooth abutments 1: zirconia copings, 2: goldcopings, and 3: zirconia supraconstruction. (c and d) Attachment system with implant abutments 1:zirconia implant abutments, 2: gold copings, and 3: zirconia supraconstruction. (e) The screw openingof the zirconia implant abutment was filled with a resin.

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In all 3 cases, the superstructures were

extended only up to teeth number 3 and 14

with cantilevers. The cantilevers at teeth

number 3 and 14 were supported by the

veneer material on the mucosa (Figures 6

through 8).

In the IMPL patient, teeth number 2 and

15 manifested improved mobility (class I) and

inflammation-free periodontal conditions at

the time of the prosthetic restoration. For this

reason, both teeth were retained according to

the patient’s wishes. Two zirconia crowns

(Panavia, Kuraray Europe, Frankfurt/M, and

Germany) were fabricated and adhesively

inserted on the existing, old primary telescopic

crowns number 2 and 15 which were intact and

free of caries (Figure 6a through f ).

Maintenance

Follow-up examinations were performed at

the time of loading, and were considered the

baseline examinations (BSL). At the BSL, and at

the 1-, 2- and 3-year examinations after

loading, the implants and/or natural teeth

were examined at 4 sites per tooth. These

examinations measured bleeding on probing

(BOP) and plaque index11; in addition, a

periodontal probe (UNC 15, Hu-Friedy, Lei-

men, Germany) was used to estimate probing

attachment level (PAL) for implants and

clinical attachment level (CAL) for natural

teeth. PAL was defined as the distance in

millimeters between the deepest point of the

peri-implant pocket and the margin of the

zirconia implant abutment. CAL was defined

as the distance between the deepest point of

the periodontal pocket and the margin of the

zirconia primary crowns. All measurements

were rounded up to the nearest millimeter.

RESULTS

Three patients were treated (IMPL, PERIO,

and IMPL-PERIO). Ten dental implants were

FIGURE 6. IMPL patient. (a–c) Clinical view right – front – left. (d) Orthopantomograph. (e) Palatal view. (f )Anterior area close-up.

FIGURES 7 AND 8. FIGURE 7. PERIO patient. (a–c) Clinical view right – front – left. (d) Orthopantomograph.FIGURE 8. IMPL-PERIO patient. (a) Orthopantomograph. (b and c) Clinical view.

Zafiropoulos et al

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placed in the maxillae of 2 patients (IMPL

and IMPL-PERIO), and 9 maxillary natural

teeth in the maxillae of 2 patients (PERIO and

IMPL-PERIO) were used as retainers for the

restorations. The maxillae of all 3 patients

were restored with removable telescopic

dentures. Implant abutments, copings for

natural tooth abutments, and superstruc-

tures were fabricated using CAD/CAM. In all

cases, electroformed gold copings were

fabricated as secondary telescopes.

The patients were observed over a period

of 3 years. None of the patients reported any

unusual pain or discomfort, abscess, swell-

ing, or allergic reactions during the course of

treatment. No implants or natural teeth were

lost during the observation period. Further-

more, no fractures were observed in the

zirconia abutments, the superstructures, or

the ceramic veneers (Figure 9).

The small sample size and limited num-

ber of measurements in this study rendered

it not amenable to statistical analysis. How-

ever, there were no observed changes in

BOP and plaque index measurements be-

tween the BSL and subsequent examina-

tions. The mean range of BOP values for the

maxillary natural teeth was 5% and that for

the implants was 2%–4%. Plaque index

scores ranged from 5%–8%. At the BSL, the

mean PAL was 1 mm. The PAL deteriorated

by 1 mm at the year 1 examination and a

further 0.5 mm at the year 3 examination.

The mean CAL at the BSL was 2.5 mm, and

the range was 3.5–4 mm between the year 1

and year 3 examinations.

DISCUSSION

In the present study, the maxillae of 3

patients were restored with removable,

telescopic crown-retained, palate-free den-

tures. All implants and natural teeth, prima-

ry telescopes, and supraconstructions re-

mained functional, and none of the patients

suffered complications thoughout the 3-

year observation period.

FIGURE 9. Three-year clinical view. (a) Zirconia copings. (b) Zirconia implant abutment.

Zirconia Telescopic Dentures for Maxilla Rehabilitation

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The use of ceramics in dentistry and

dental technology has increased in recent

years. Among other materials, zirconia has

been used to manufacture frameworks due

to its good mechanical and biocompatible

properties.12–15 Importantly, during the en-

tire observation period of the present study,

no biological or mechanical complications

were observed, and all reconstructions re-

mained functional. This observation is in

agreement with the few studies that have

examined removable dentures retained on

teeth or implants using zirconia for the

fabrication of copings and/or implant abut-

ments.12,16–20 The present study differs from

other published studies in that the supra-

structures were also fabricated from zirconia

and not from metal. The periodontal and

peri-implant findings were overall very pos-

itive.

Clinical studies of zirconia implant abut-

ments and copings have shown them to

have favorable stability and to exhibit a

survival outcome similar to that of gold or

titanium structures.17,18,21 Similar to prior

studies, we found the bone level around the

implants and/or natural tooth abutments to

be stable and the soft tissue to be

healthy.12,16,17,19–21 Recent studies have re-

ported that zirconia shows a lower bacterial

colonization potential than titanium in

vivo.22–25 It has been further asserted that

this material can help stabilize soft tissue

against inflammation and contribute to the

stability of the crestal bone level around the

implants.17,23,25,26

In the present study, low plaque accu-

mulation and low BOP were also observed.

The probing depth of the periodontal or

peri-implant areas was stable and no gingi-

val recessions were seen. Gingival recessions

may cause esthetic complications that must

be surgically managed, particularly when

they occur in the anterior region. These

may lead to patient dissatisfaction and

caries. Although in the cases presented here

no such problem was observed, the occur-

rence of gingival recessions in the future

cannot be ruled out. In such a case, too, the

removable telescopic crown-retained con-

struction offers the great advantage that the

lip shield covers these areas, and plastic

periodontal surgery for the purpose of

correcting the soft tissue contours is not

necessary.

A number of studies have reported on the

fabrication of zirconia copings for providing

retention of a telescopic crown-retained over-

denture.12,16,20 Other studies report positive

mechanical properties of zirconia copings in

fixed restorations.12,16,25,27,28 No fractures of

the zirconia copings were observed in the

present study. These copings proved to be a

successful alternative to classic gold copings,

especially when the patient’s esthetic de-

mands are high. However, the preparation

angle of the natural abutments, the thickness

of the zirconia, and the occlusal load must

be precisely factored in.29–31

The secondary telescopes were manufac-

tured by galvanoforming and electroform-

ing. This process yields a precisely-fitting

secondary coping that closely mates with

the primary telescope with a gap of 12–

30 mm. The gold electroformed coping saves

space and is made of high-quality material.

In order for its shape to remain stable, it

must be completely surrounded by the

superstructure framework and may not

merely be adhered to the veneer.9,10,16 The

fixation of the electroformed copings should

be done after the veneering of the supra-

construction is completed. The combination

of both materials, zirconia and electroform-

ing copings, used with the proper technol-

ogies, results in a prosthetic reconstruction

of high quality, good fit. and biocompatibil-

ity.

Developments in CAD/CAM technology

have resulted in discernible improvement in

these methodologies.32–34 New technologies

must take into account the specific require-

Zafiropoulos et al

Journal of Oral Implantology 463

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ments of dental technology and dentistry,

and a great deal of time is required before

they become routine. In the present study,

all parts of the telescope-borne removable

reconstructions were fabricated using CAD/

CAM. Over the 3-year observation period, no

complications were noted from the individ-

ual parts made using this technology.

Nevertheless, the lack of long-term results

must be borne in mind. We do not yet know

whether the mechanical and prosthetic-

specific properties of the material will remain

satisfactory over the long term, and whether

they will prove to be as valuable as the

established classic methods and materials of

dental technology. Randomized long-term

studies with a large number of test subjects

are required. Even if the overall number of

restorations fabricated with CAD/CAM, espe-

cially all-ceramic frameworks made of mate-

rials such as zirconia, remain comparatively

fewer than conventionally-fabricated frame-

works, this technology has great potential

for economical and biocompatible restora-

tions using innovative materials that are

esthetically and functionally superior.

This report presents the option of restor-

ing the maxilla with classic techniques from

oral implantology as well as prosthetic

dentistry using modern dental materials.

The esthetic and functional results over the

3-year observation period were very positive.

Long-term results from large, preferably

randomized studies would be desirable and

necessary to establish greater clarity regard-

ing the long-term potential changes in the

properties of zirconia. It would, of course, be

possible to reconstruct the maxillae of the

patients discussed by hard and soft tissue

augmentation in order to allow the fabrica-

tion of a fixed prosthetic restoration. In such

cases, one is confronted with the dilemma of

whether all the possibilities of modern

surgery should be exhausted, or if it would

be more desirable to pursue ‘‘the path of

least resistance’’ and combine classic and

modern methods. If the latter route is taken,

we as surgeons or periodontists should give

more weight to the option of restorative

dentistry.

ABBREVIATIONS

BOP: bleeding on probing

BSL: baseline examinations

CAL: clinical attachment level

PAL: probing attachment level

NOTES

The authors report no conflicts of interest

related to this study. No financial or material

support was provided by any company to the

authors or the patients involved in this study.

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