LAUSR

OBJECTIVES To evaluate the peri-implant tissue changes and aesthetic outcomes of cemented and screw-retained crowns of single-tooth implants in the aesthetic zone using zirconia abutments. MATERIAL AND METHODS An electronic search was performed on nine databases. The risk-of-bias was assessed by the revised Cochrane risk-of-bias tool for randomized (RoB 2) and non-randomized (ROBINS-I) clinical trials. Marginal bone level change, soft tissue thickness, bleeding on probing, probing depth, survival rates of implants and crowns, complications, plaque and papilla indexes, and pink aesthetic score data were extracted and analysed. The certainty of evidence was accessed through the GRADE approach. RESULTS Nine records were included and 7 were used in the meta-analyses. Screw-retained crowns presented greater marginal bone level change (MD -0.04 [-0.08, -0.00] p=0.04, I2 =0%) compared to cemented crowns up to 1-year. At 3 and 4 years no significant differences (p>.05) were observed. Soft tissue thickness did not differ between groups (p>0.05). The bleeding on probing was higher in cemented group than in screw-retained crowns at 1-year (MD 0.17 [0.08, 0.27] p=0.0005, I2 =0%), at medium-term periods (3 and 4 years) no statistically significant differences (p>0.05) were observed for this outcome. Probing depth, survival rates of implants and crowns, complications, and plaque index as well as aesthetic analysis using the papilla index and pink aesthetic score did not differ statistically (p>0.05) between both retention systems at short and medium-term periods. CONCLUSION The connection system considering zirconia abutments presented no influence on peri-implant parameters and aesthetics evaluation for medium-term periods (3 and 4 years).