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 periimplant 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 Xiao-Lei Lv and Shu-jiao Qian contributed equally to this study.

Objective:The objective of this study is to systematically analyze the effects of diabetes mellitus/hyperglycemia (DM/HG) on peri-implant biomarkers and clinical and radiographic outcomes in patients undergoing implant treatment.Materials and Methods: PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases were searched up to March 2022. Studies reporting on peri-implant biomarkers, and clinical and radiographic outcomes in patients with different glycemic status levels (HbA1c) were included. Several analyses were conducted, such as meta-analysis, sensitivity analysis, dose-response meta-analysis (DRMA), and robust error meta-regression (REMR).Results: A total of 10 studies and 634 participants were included for analysis, with a maximum follow-up of six years in function. The level of advanced glycation end products (AGEs) in peri-implant crevicular fluid (PICF) was significantly higher in the DM/ HG group than in the healthy group (p < .01). Subgroup analyses showed that a set of negative regulators of bone metabolism (including IL-6, TNFα, IL-8, and RANKL) were significantly higher in the DM/HG group (p = .01). Implant survival rate (100%) was not compromised in patients with an HbA1c level less than 10%. Outcomes of implant stability quotient (ISQ) values, bleeding on probing rate (BOP%), probing depth (PD), and marginal bone loss (MBL) in the DM/HG group were significantly worse than those in the healthy group (p = .04, <0.01, 0.01, <0.01, respectively). DRMA results showed AGE accumulation in PICF, PD, and MBL worsened in a dose-response dependent manner with elevated HbA1c levels (<6%, 6-8%, >8%; p = .04, 0.02, <0.01, respectively).Conclusions: DM/HG can upregulate negative regulators of bone metabolism and compromise peri-implant health. In addition, there are dose-response relationships between HbA1c levels and AGE accumulation in PICF, PD, and MBL.

Dental implants have become the leading choice for patients who lose teeth; however, dental implantation is challenged by peri-implant infections. Here, calcium-doped titanium was fabricated by the combinational use of thermal evaporation and electron beam evaporation in a vacuum; then, the material was immersed in a calcium-free phosphate-buffered saline solution containing human plasma fibrinogen and incubated at 37 °C for 1 h, creating calcium- and protein-conditioned titanium. The titanium contained 12.8 ± 1.8 at.% of calcium, which made the material more hydrophilic. Calcium release by the material during protein conditioning was able to change the conformation of the adsorbed fibrinogen, which acted against the colonization of peri-implantitis-associated pathogens (Streptococcus mutans, UA 159, and Porphyromonas gingivalis, ATCC 33277), while supporting the adhesion and growth of human gingival fibroblasts (hGFs). The present study confirms that the combination of calcium-doping and fibrinogen-conditioning is a promising pathway to meeting the clinical demand for suppressing peri-implantitis.