The present study was conducted in the Department of Prosthodontics and Crown & Bridge, Subharti Dental College and Hospital, Meerut is to evaluate biological, mechanical and patient reported parameters associated with Angulated Screw Channel abutments and Multi unit abutments for fabrication of screw retained implant crowns in anterior esthetic zone. For the study 20 patients were selected who needed implants in maxillary anterior region. The implants were placed either crestal or subcrestal position to accommodate the angulated abutments (Angulated Screw Channel and Multi unit abutments) in a way that it lie within the prosthetic envelop. Depending on the group assigned, a screw retained crown was made either on ASC abutment or MU abutment. All the parameters were evaluated at the time of crown placement and 12 months after crown placement. The data then was statistically evaluated and compared. In the present study, implant survival was found 100% in both groups. MBL decreased significantly from baseline to 1-year follow-up in both groups. MBL in the MU group was slightly lower than in the ASC group but this difference was not statistically significant. Also, no statistically significant difference was found in the modified plaque index, modified sulcus index, and gingival index at baseline and 1-year follow-up values in both groups.

The RTL value was significantly lower (p<0.003) in the ASC group than MU group at baseline, however, no statistically significant difference in RTL and screw loosening was found at 1-year follow-up between both the groups. There was no statistically significant difference in patient-reported parameters. Limitations of this study were the small sample size and short-term follow-up period. The high cost and limited documented clinical success rate of these abutments as single-unit implant restoration have restricted their application in day-to-day practice. Thus, prospective studies with long-term follow-ups and larger sample sizes are required to understand the possible biological, mechanical and patient-reported parameters, and draw concrete decisions about the superiority of either of the abutments. Within the limitations of this study, it can be stated that the ASC and MU abutments with anti-rotation feature can be used as an effective alternative for screw retained restorations in cases of non-axially loaded implant with excellent clinical performance after 1 year of function.