Introduction
Methods
Search strategy
Stability assessment criteria and classification of the evidence level
Stability assessment criteria
Classification of the study type according to the evidence level
Grade | Study type |
---|---|
1 (high) | Systematic literature review targeting RCTs (systematic review with/without meta-analysis) |
2 | Randomized controlled trial, systematic literature review targeting category 3 |
3 | Quasi-RCT, cohort study, case-control study, observational/analytic study |
4 (low) | Cross-sectional study, case series, before/after study, case report, non-analytic study |
Main text
Grade | Study type | Result (literature) | |
---|---|---|---|
Domestic | International | ||
1 | Systematic literature review targeting RCTs (systematic review with/without meta-analysis) | 0 | 0 |
2 | RCT | 0 | 0 |
Systematic literature review targeting category 3 | 0 | 5 | |
3 | Quasi-RCT | 0 | 0 |
Cohort study | 3 | 4 | |
Case-control study | 0 | 3 | |
Observational, analytic study | 0 | 0 | |
4 | Cross-sectional study | 0 | 0 |
Case series | 0 | 1 | |
Case report | 6 | 6 | |
Non-analytic study | 0 | 0 |
Domestic literature
Evidence level 3
Author | Study type | Patient (person)/implant (unit)/restoration | Implant location | Prosthesis type | Zirconium abutment | F/U period | Outcome | Conclusion |
---|---|---|---|---|---|---|---|---|
Kim et al. [34] | Prospective cohort | 213/611/328 | Anterior/posterior | Single unit/multi-units with pontic | Alumina-toughened zirconium abutment (ZirAce) | 3.6 years (1–12.8 years) | Survival rate of zirconium abutments - 98.3% (single) - 99.2% (pontic without multi-units) - 96.1% (pontic with multi-units) Complication rate - 19.7% (single) - 3.9% (pontic without multi-units) - 3.8% (pontic with multi-units) | Zirconium abutments have an excellent long-term survival rate. For the restoration of a single posterior tooth, further studies are required. |
Kim et al. [15] | Retrospective cohort | 65/158/85 | Anterior/premolar/molar | Single crown/splint crown/bridge | Alumina-toughened zirconium abutment (ZirAce) | 78 months (60.9–117.5) | Zirconium fracture, screw fracture, and screw loosening were not observed for 5 years. Restoration success rate: 95.3% | Complications occurred after 5 years. The 5-year use is stable. |
Bae et al. [16] | Prospective cohort | 17/37 | Maxilla mandible | Not mentioned | Zirconium/alumina composite abutment | 12 months | No abutment Mean alveolar loss - Maxilla: 0.56 ± 0.26 - Mandible: 0.68 ± 0.30 Histological examination - Junctional epithelium Height: 2.09 mm Width: 0.51 mm | The zirconium alumina composite abutment is clinically stable. |
Evidence level 4
Author | Study type | Implant location | Abutment | F/U period | Outcome |
---|---|---|---|---|---|
Kim et al. [35] | Case report | #11 | Customized zirconium myplant | Not mentioned | Interdental papillar 100% filled The shape and the color are harmonious. Functionally and esthetically satisfactory |
#21 | Customized zirconium myplant | 6 months | Harmonious with the adjacent teeth | ||
#11 | Customized zirconium myplant | Not mentioned | Not mentioned | ||
Byeon et al. [31] | Case report | #21 | Not mentioned | 2 months after installing the prosthesis | Esthetic, oral hygiene maintained |
Lee et al. [32] | Case report | #23 | Customized zirconium abutment | 6 months after installing the prosthesis | Stable |
Kim et al. [33] | Case report | #11 #21 | Ready-made zirconium abutment (Osstem Korea) | 10 months after treatment | Stable |
Byeon et al. [36] | Case report | #11 | Not mentioned | Not mentioned | Not mentioned |
Yun et al. [37] | Case report | #21 | Not mentioned | Not mentioned | Esthetic, oral hygiene maintained |
International Literature
Evidence level 2
Author | No. of studies (clinical studies) | Outcome | Conclusion |
---|---|---|---|
Medeiros et al. [17] | 16 | 1. The zirconium abutments showed excellent soft-tissue reactions (3 studies). 2. The gingival recession increased in the zirconium abutments (1 study). 3. No biological difference was observed between the titanium and zirconium abutments (9 studies). 4. The zirconium abutments provided the gingival contour and anatomical shape of the natural teeth as well as have excellent esthetic features (3 studies). | 1. Zirconium abutments are recommended for the anterior teeth. 2. Long-term studies are required to evaluate biological reactions. |
Guess et al. [18] | 18 (4) | The survival rate of the zirconium abutments was 100% (F/U period: 6 months-4 years). | As there are limited clinical data on zirconium abutments, their routine use in dental clinics is not recommended. |
Gomes et al. [19] | 20 (5) | 1. The survival rate of the zirconium abutments was good. 2. The titanium abutments had more bone resorption than the zirconium abutments. 3. The zirconium abutments were esthetically and functionally stable. 4. No zirconium abutment fracture was observed for four years. 5. The zirconium abutments had less bacteria accumulation than the titanium abutments. | More studies on the long-term clinical success of zirconium abutments are required. |
Nakamura et al. [20] | 25 (8) | 1. The zirconium abutments were acceptable for anterior teeth in the biological and mechanical aspects. 2. Zirconium had less early plaque accumulation than titanium. | The zirconium abutment has the potential to be used as a dental implant abutment material. |
Linkevicius et al. [21] | 9 (1) | Titanium abutments do not maintain a higher bone level than gold, aluminum oxide, and zirconium abutments. | Due to the lack of clinical studies, the stability of zirconium abutments cannot be determined. |
Evidence level 3
Author | Study type | Patient/implant | Implant location | Prosthesis type | Abutment | F/U period | Outcome | Conclusion |
---|---|---|---|---|---|---|---|---|
Zembic et al. [3] | Prospective cohort | 18/40 | Canine, premolar, molar | Single crown | Zirconium, titanium | 5.6 years (4.5–6.3) | 1. Prosthesis survival rate: 100% 2. No significant difference in PD, PCR, BOP, and BL | No statistically or clinically significant difference in the 5-year survival rate |
Van Brakel et al. [23] | Case-control study (histological examination) | 22/44 | Mandible (canine region) | No prosthesis | Zirconium, titanium | 3 months | 1. No significant difference in the vascular density of the adjacent tissues 2. No significant difference in the inflammation level | 1. No difference in the soft-tissue health 2. No difference in the biological reactions |
Bressan et al. [38] | Case-control study (The thickness and color of the soft tissue were measured.) | 22/22 | Maxilla anterior | Single crown | Gold, zirconium, titanium (all customized) | Not mentioned | 1. The color of soft tissue around the implant is significantly different from that of the opposite tooth. 2. The titanium abutments showed a significantly greater color difference in soft tissue compared with gold or zirconium abutments. 3. The information on the difference in the soft-tissue thickness and the color difference cannot prove their correlations. | 1. The color of the soft tissue around the implant is different from that of natural teeth regardless of the abutment materials. 2. The titanium abutments show a significantly greater color difference in the soft tissue compared with the gold or zirconium abutments. 3. The thickness of the soft tissue around the implant is not an important element in the effect of the abutment on the soft-tissue color. |
Van Brakel et al. [22] | Case-control study | 22/44 | Mandible (canine region) | No prosthesis | Zirconium, titanium | 3 months | 1. In the two abutments, similar levels of bacteria were detected. 2. No significant difference in the soft-tissue condition around the implant | No difference in the soft-tissue health |
Zembic et al. [7] | Prospective | 18/40 | Canine, premolar, molar | Single crown | Zirconium, titanium | 36 months (31.5–53.3) | 1. No significant difference in PD, PCR, BOP, and BL 2. The two abutments showed biological stability. 3. The degree of gingival discoloration in the two abutments was similar to that of the gingiva of natural teeth. | The zirconium and titanium abutments had the same survival rate and mechanical, biological, and esthetic outcomes during the 3-year follow-up period. |
Sailer et al. [6] | Prospective cohort | 22/40 | Canine, premolar, molar | Single crown | Zirconium, titanium | 12.6 months (± 2.7) | 1. Prosthesis survival rate: 100% 2. No difference in PD, PL, and BOP 3. The colors of the soft tissue around the zirconium and titanium abutments are similar to the gingival color of natural teeth. | During the 1-year follow-up, the survival rates of the zirconium and titanium abutments are the same, and similar esthetic outcomes are shown. |
Glausser et al. [2] | Prospective cohort | 27/54 | Incisor, canine, premolar | Single crown | Zirconium, titanium | 48 months | The survival rate of the abutments: 100% | Zirconium abutments are very stable in supporting the single-tooth implant restoration at the anterior and premolar regions. |
Evidence level 4
Author | Study type (no. of samples) | Implant location | Abutment | F/U period | Outcome |
---|---|---|---|---|---|
Lee et al. [24] | Case series (9) | Maxilla anterior | Zirconium abutment | 52 weeks after installing the prosthesis | Esthetic, no abutment fracture or screw loosening |
Aydin et al. [25] | Case report (1) | #22 | Zirconium abutment | Six months after installing the prosthesis | No difference in PCR, BOP, PD, and BL |
Kalman et al. [26] | Case report (1) | #22 | Customized zirconium abutment (Nobel Procera) | Not mentioned | Esthetic |
Wadhwani et al. [27] | Case report (1) | #12 | Customized abutment (Straumann) | Not mentioned | Esthetic |
Mahn et al. [28] | Case report (1) | #11 | Customized abutment | Not mentioned | Esthetic |
Schneider et al. [29] | Case report (1) | #21 | Zirconium ART EASY abutment (Thommen Medical) | Not mentioned | Esthetic |
Tan et al. [30] | Case report (1) | #21 | Zirconium abutment (Astra Tech Inc., USA) | Not mentioned | Customized titanium abutment: excellent gingival contour, gray shade in the gingival area; zirconium abutment: no gray shade in the gingival area |