Clinical, radiographic, and immunological evaluation of angulated screw-retained and cemented single-implant crowns in the esthetic region: A 1-year randomized controlled clinical trial.

BACKGROUND: Screw-retained implant crowns are considered more biologically compatible than cemented crowns due to the absence of excess cement. However, traditional screw-retained implant crowns are not viable when the access hole of the screw channel would need to be located in an esthetic area, which would compromise the esthetic outcome of the treatment. PURPOSE: To evaluate the clinical, radiographic, and immunological outcomes of angulated screw-retained and cemented single-implant crowns in the esthetic region. MATERIALS AND METHODS: The study was a single-center, open-label, randomized controlled clinical trial. Eligible patients were randomly placed in two groups: angulated screw-retained group (AG) and cemented group (CG). Implant survival rate, bleeding on probing rate (BOP%), probing depth (PD), modified plaque index (mPI), marginal bone loss (MBL), concentrations of pro-inflammatory cytokines (TNF-α, IL-6) in peri-implant crevicular fluid (PICF), mechanical complications, and pink esthetic score/white esthetic score (PES/WES) were evaluated. RESULTS: Fifty-six patients (AG: 29, CG: 27) attended the 1-year examination. The drop-out rate was 6.67%. No implant failure was found in both groups during the observation period. BOP% was significantly lower in the AG than that in the CG (mean, 21.84% ± 19.97% vs. 37.04% ± 26.28%, p = 0.018). The concentration of TNF-α in PICF was significantly higher in the AG than that in the CG (median, 13.54 vs. 4.62, p = 0.019). No significant difference of PD, mPI, MBL, IL-6, or mechanical complication rates was found between the two groups. Mean scores for PES/WES were 21.71 and 21.64 in the AG and CG, respectively. CONCLUSION: Based on the present results, both treatment options showed acceptable clinical outcomes in the short term. Angulated screw-retained crowns might benefit the peri-implant soft tissue. However, studies with long-term follow-up are needed to confirm whether the higher concentration of TNF-α will compromise the long-term outcomes of treatment.

Angulated screw-retained and cemented implant crowns following flapless immediate implant placement in the aesthetic region: A 1-year prospective cohort study.

PURPOSE: To compare the short-term clinical and radiographic outcomes of angulated screw-retained and cemented implant crowns following flapless immediate implant placement. MATERIALS AND METHODS: The study was designed as a prospective cohort study with 1-year follow-up. Eligible patients were divided into two groups according to restoration type: the angulated screw group (AG) and the cemented group (CG). Implant survival, marginal bone loss, mechanical complications, probing depth, bleeding on probing% and pink aesthetic score were evaluated. RESULTS: After 1 year of loading, the implant survival rate was 100% in both groups (AG, n = 23; CG, n = 20). A significantly lower bleeding on probing% was found in the AG than in the CG (11.6 ± 19.1% vs. 33.3 ± 33.8%, P = 0.04). No significant differences in marginal bone loss, probing depth and mechanical complication rates were found between the two groups (P = 0.53, 0.48, 0.41, respectively). The overall pink aesthetic score value was 8.96 ± 0.88 in the AG and 8.98 ± 0.62 in the CG at 1-year examination (P = 0.96). The percentage of excellent pink aesthetic scores (≥ 9) value increased from 48% at baseline to 83% at 1 year in the AG, and from 45% at baseline to 85% at 1 year in the CG. CONCLUSION: Based on the 1-year results, both treatment options provide high implant survival, a stable marginal bone level and excellent aesthetic outcomes in the short term. Angulated screw-retained crowns might benefit the long-term peri-implant conditions.