[Short-term comparison of the clinical efficacy of angulated screw-retained implant crowns and cemented implant crowns in esthetics region].

PURPOSE:To compare the clinical efficacy of angulated screw channel abutments and prefabricated titanium abutments on the restoration of single implant crowns in esthetics region. METHODS:The study was a prospective, single center, randomized controlled trial. Patients with the need of restoration of single tooth in esthetics region were included from June 2018 to June 2019. Forty patients were randomly assigned into two groups: screw-retained crowns with angulated screw channel abutments(angulated group, AG) and cemented crowns with prefabricated Ti abutments (cemented group, CG). Clinical and radiological evaluations were performed on the day of final crowns delivery and 6 months later. Implant survival rate, marginal bone loss (MBL), mechanical complications, peri-implant conditions (Probing depth, PD; bleeding on probing, BOP%), pink esthetics score/white esthetics score(PES/WES) and patients' satisfaction were assessed. The data was analyzed with SPSS 19.0 software package. RESULTS:Thirty-six patients (AG: 19, CG: 17) attended the 6-month clinical trial. Implant survival rates were both 100% in two groups. The MBL was (0.21±0.18) mm for AG and (0.38±0.40) mm for CG (P>0.05). The BOP% was significantly higher in AG than that in CG (P=0.04). No significant difference of mechanical complications, PD, PES/WES and patients' satisfaction was found between the two groups(P>0.05). CONCLUSIONS:Based on the present results, both treatment options show acceptable clinical outcomes in the short term. Angulated screw-retained crowns may benefit the peri-implant soft tissue; however, studies with long-term follow-up are needed to verify the results.