| PubMed ID | Author / Year | Patient Group | Study type (level of evidence) |
| 21070378 | Bressan/2011 | 20 Patients | Case Control Study |
| Key results | Ceramic crowns were placed on ceramic, gold or titanium implant abutments in the anterior maxilla on twenty patients. Peri-implant soft tissue color was measured through a spectrophotometer. The abutment materials were analyzed with a statistical analysis and the normality of the quantitative variables was verified with the Shapiro-Wilk test. At 95% confidence intervals and P<0.05, the least square mean +/- standard errors were noted with the three abutment materials analyzed yielding the following: gold 8.9 +/- 0.4, titanium 11 +/- 0.4, and zirconium 8.5 +/- 0.4. All abutments showed a difference in color compared to soft tissue around natural teeth. A greater color difference (less desirable) was seen with titanium abutments and a lesser color difference (more desirable) was seen with both ceramic and gold abutments. | ||
| 23725369 | Delben/2013 | 60 crowns equally divided among 3 different abutment types | Case Report Study |
| Key results | This study analyzed the effect of veneering materials on screw joint stability and evaluated the pre-load maintenance of abutment screws with different abutments and veneering materials. Torque/detorque was measured (p < 0.05, Fisher’s exact test) before and after mechanical cycling. Although a statistically significant difference was noted between test groups with ceramic, gold and titanium abutments, detorque reduction was observed regardless of the abutment type and veneering material. “Although the conditions of this in vitro study have not demonstrated the superiority of some material regarding the screw joint stability, the selection of abutment type and esthetic veneering material should be judicious due to its relevance to stress distribution on implants and supporting structures.” | ||
| 22708959 | Hosseimi/2012 | 59 Patients treated with 98 implant restorations | Randomized Controlled Trial |
| Key results | This clinical study measured outcome variables of 64 all-ceramic and 34 metal-ceramic crowns placed on 52 zirconia, 21 titanium and 25 gold implant abutments. Data was gathered at baseline and 3-year follow up examinations. The survival rate for the implants was 100% and 97% for the abutments and crowns. The Copenhagen Index Score measured the aesthetic outcome and the patient reported outcomes were recorded using the OHIP-49 questionnaire. Although more marginal bone loss was registered at gold-alloy compared to zirconia abutments (P = 0.040), the biological outcomes at the zirconia and metal abutments were comparable. “The modified Plaque Index and modified Sulcus Bleeding Index were not significantly different at the three abutment materials. Patient reported outcome variables at different materials were not significantly different after 3 years." | ||
The Evidence
| Basic Science Rationale (Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?) |
| None available |
| Comments and Evidence-Based Updates on the CAT (FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) |
| None available |