All-ceramic restoration of zirconia two-piece implants - a randomized controlled clinical trialby Michael Payer, Alexander Heschl, Martin Koller, Gerwin Arnetzl, Martin Lorenzoni, Norbert Jakse

Clinical Oral Implants Research


Oral Surgery


Position Paper: Single-Dose Activated Charcoal

American Academy of Clinical Toxicology, European Association of Poisons Centres, Clinical Toxicologists

Single-Tooth All-Ceramic Restorations

Edward Lowe

Analysis of the intraimplant microflora of two-piece dental implants

Sönke Harder, Rainer Podschun, Livia Grancicova, Christian Mehl, Matthias Kern


Michael Payer

Alexander Heschl

Martin Koller

Gerwin Arnetzl

Martin Lorenzoni

Norbert Jakse

All-ceramic restoration of zirconia two-piece implants – a randomized controlled clinical trial

Authors’ affiliations:

Michael Payer, Norbert Jakse, Department of Oral

Surgery and Radiology, School of Dentistry,

Medical University of Graz, Graz, Austria

Alexander Heschl, Martin Koller, Gerwin Arnetzl,

Martin Lorenzoni, Department of Prosthodontics,

School of Dentistry, Medical University of Graz,

Graz, Austria

Corresponding authors:

Dr. Alexander Heschl, Dr. Martin Koller

Department of Prosthodontics

School of Dentistry, Medical University Graz

Auenbruggerplatz 12, A-8036 Graz, Austria

Tel.: +43-316-385-12976

Fax: +43-316-385-13376 e-mail:,

Key words: all-ceramic crowns, titanium implants, yttria-stabilized zirconia implants


Objectives: Aim of this controlled prospective randomized study was to evaluate the outcome of two-piece zirconia implants compared to titanium implants over a period of up to 24 months.

Material and methods: A total of 31 implants (16 zirconia/Ziterion vario Z + 15 titanium/Ziterion vario T) were inserted primary stable (>30 Ncm) in the maxilla (7) and mandible (24) of 22 patients (13 male, nine female) requiring neither bone nor soft tissue augmentation. After a healing period of 6 months in the maxilla and 4 months in the mandible, ceramic abutments were luted adhesively to the zirconia implants and definitive all-ceramic restoration was performed with high-density ceramics. Radiographic bone levels, condition of the peri-implant mucosa, aesthetic outcome, implant survival and success were recorded for up to 24 months.

Results: Measurements of mean marginal bone levels 24 months after surgery showed a significant bone loss (P < 0.001) in both groups (Ti: 1.43 (SD  0.67) vs. Zir 1.48 (SD  1.05). One zirconia implant was lost 8 months after restoration. No further complications were recorded, giving an overall survival and success rate of 93.3% for zirconia and 100% for titanium implants after a period of up to 24 months.

Conclusions: After 24 months, success rates of the two-piece ceramic implants showed no significant difference compared to control two-piece titanium implants. The bonded zirconia implant abutment connection appears to be capable with clinical application over the observed period. However, further control measurements need to confirm the presented data.

The current commercial dental implant material of choice is pure titanium. Its properties have been well documented in numerous experimental and clinical applications over the past decades. A major driver, however, for alternatives to titanium in implant dentistry is an ongoing discussion on sensitivities and allergies associated with failure of dental titanium implants (Sicilia et al. 2008; Pigatto et al. 2009). To date, there seems to be no evidence for clinical relevance of this hypothesis (Wenz et al. 2008). Further potential aesthetic advantages of ceramics over titanium as implant material in the anterior zone and in patients with compromised soft tissue have been used as arguments to justify the search for alternative materials. But here, too, little reliable data are available on the aesthetic outcome of zirconia implants compared to titanium implants. Even though it is at present hard to find evidence-based arguments for the application of alternatives to titanium, the current demand for metal-free materials in dentistry is keeping the search for alternatives to titanium in implantology alive (Wohlwend et al. 1996; Heydecke et al. 1999;

Zembic et al. 2009).

As a potential alternative to titanium, zirconium dioxide (ZrO2, zirconia) – an inert, nonresorbable and biocompatible metal oxide – exhibits promising chemical and physical properties (Stevens 1986; Marx 1993;

Geis-Gerstorfer & F€assler 1999; Piconi &

Maccauro 1999). Zirconia, usually available as 3–5 M% yttrium-stabilized tetragonal polycrystal (Y-TZP; Kelly & Denry 2008), was first used in orthopaedic surgery for ball heads in total hip replacement. Compared to earlier alumina ceramic implants, which had to be withdrawn from the market due to high fracture rates in clinical use, zirconia seems to have a higher potential for use in implant dentistry (Schulte et al. 1992; Sandhaus &


Accepted 6 January 2014

To cite this article:

Payer M, Heschl A, Koller M, Arnetzl G, Lorenzoni M, Jakse

N. All-ceramic restoration of zirconia two-piece implants – a randomized controlled clinical trial.

Clin. Oral Impl. Res. 26, 2015, 371–376 doi: 10.1111/clr.12342 © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd 371

Pasche 1997; Kohal et al. 2004; Andreiotelli et al. 2009; Hobkirk & Wiskott 2009). In experimental models, Y-TZP has been shown to be biocompatible and to be susceptible to mechanisms of osseointegration (Albrektsson et al. 1985; Akagawa et al. 1993; Akagawa et al. 1998; Schultze-Mosgau et al. 2000;

Scarano et al. 2003) and de novo bone formation on roughened surface textures (Sennerby et al. 2005). Improvements in material stability of Y-TZP have allowed successful clinical application of zirconia-fixed partial dentures, crowns and implant abutments in humans (Yildirim et al. 2000; Andersson et al. 2003;

Glauser et al. 2004).

Since so far no applicable and stable connection between zirconia abutments and implants could technically be realized,

Y-TZP has predominantly been used for the fabrication of single-piece implants (Payer et al. 2013). Over the last decade, numerous types of zirconia single-piece implants had been introduced in the market, but interestingly reliable clinical data are still very limited (Gahlert et al. 2013; Kohal et al. 2013).

A major drawback of single-piece implants in general, but especially in the aesthetic zone, is a reduced prosthetic versatility due to a lack of options for abutment angulation, potentially leading to compromised implant positioning. This is especially relevant for zirconia single-piece implants, for which insufficient data on the effects of intra-oral grinding as well as patients requiring bone augmentations are available (Wenz et al. 2008).