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In order to enhance the corrosion resistance of the cast Al - Cu - Mg - Ag alloy, a micro - arc oxidation (MAO) coating was prepared on the surface of the alloy and then sealed with silicone epoxy resin. The corrosion resistance of the Al - MAO coating system before and after sealing treatment was analyzed by electrochemical test, salt spray test and full immersion test. Results showed that after the corrosion test, the cast Al - Cu - Mg - Ag alloy corroded seriously, a large number of corrosion pits appeared along the grain boundary, and the tensile strength of alloy decreased by about 60 MPa; as for the Al - MAO coating system, the corrosion medium corroded the alloy substrate through the micro pores on the surface of the coating, a large number of white spot - like corrosion products appeared on the surface, and its tensile strength decreased by about 25 MPa. The effects of sealing treatment on the Al - MAO coating were as follows: the corrosion current density reduced from 2.62×10-8A/cm2 to 5.52×10-12A/cm2; the corrosion potential positively shifted from -589 mV to -342 mV; the low - frequency impedance increased from～105 Ω·cm2 to ～109 Ω·cm2; after the salt spray test and the full immersion test, no corrosion occurred; and the tensile strength basically remained the same. After the sealing treatment, the surface defects of the MAO coating were sealed, and a dense ceramic - organic composite coating formed on the alloy surface, which greatly reduced the corrosion rate and significantly improved the corrosion resistance of the alloy system.

Purpose: This is a clinical study to compare immediate and staged impression methods in a complete digital workflow for single‐unit implants in the posterior area. Materials and Methods: Sixty patients requiring single‐unit implant crowns were enrolled. Forty patients were assigned to the test group, immediate digital impression after implant surgery with crown delivery 4 months later. The remaining 20 patients were assigned to the control group, staged digital impressions 4 months after implant surgery, and crown delivery 1 month later. Both workflows involved free‐model CAD‐CAM crown fabrications. The crowns were scanned before and after clinical adjustment using an intraoral scanner (TRIOS Color; 3Shape). Two 3D digital models were trimmed and superimposed to evaluate the dimensional changes using Geomagic Control software. Chairside times for the entire workflow were recorded. Kruskal–Wallis was performed to compare crown adjustments between two groups, while One‐way ANOVA was used to compare chairside time durations between the test and control groups. Results: All crowns were delivered without refabrication. The average maximum occlusion adjustment of crowns was −353.2 ± 207.1 μm in the test group and −212.7 ± 150.5 μm in the control group (p = 0.02). The average area of occlusal adjustment, measured as an area of deviation larger than 100 μm, was 14.8 ± 15.3 and 8.4 ± 8.1 mm2 in the test and control groups, respectively (p = 0.056). There were no significant differences in the mesial and distal contact adjustment amounts, or the maximum deviations of the proximal area, between the two groups. The mean chair‐side time was 50.25 ± 13.48 and 51.20 ± 5.34 min in the test and control groups, respectively (p = 0.763). Conclusions: The immediate impression method in the digital workflow for single‐unit implants required more occlusal adjustments of crowns but showed similar chairside times compared to the staged impression method. [ABSTRACT FROM AUTHOR]

The regenerative treatment of infectious vertical bone defects remains difficult and challenging today. Current clinical treatments are limited in their ability to control bacteria and infection, which is unfavorable for new bone formation and calls for a new type of material with excellent osteogenic and antibacterial properties. Here a multifunctional scaffold is synthesized that mimics natural bone nanostructures by incorporating silver nanowires into a hierarchical, intrafibrillar mineralized collagen matrix (IMC/AgNWs), to achieve the therapeutic goals of inhibiting bacterial activity and promoting infectious alveolar bone augmentation in rats and beagle dogs. An appropriate concentration of 0.5 mg mL−1 AgNWs is selected to balance biocompatibility and antibacterial properties. The achieved IMC/AgNWs exhibit a broad spectrum of antimicrobial properties against Gram‐negative Porphyromonas gingivalis and Gram‐positive Streptococcus mutans. When the IMC/AgNWs are cocultured with periodontal ligament stem cells, it possesses excellent osteoinductive activities under both non‐inflammatory and inflammatory conditions. By constructing a rat mandibular infected periodontal defect model, the IMC/AgNWs achieve a near‐complete healing through the canonical BMP/Smad signaling. Moreover, the IMC/AgNWs enhance vertical bone height and osseointegration in peri‐implantitis in beagle dogs, indicating the clinical translational potential of IMC/AgNWs for infectious vertical bone augmentation. [ABSTRACT FROM AUTHOR]

Aim: To explore the features of and potential landmarks that predict crestal ridge remodeling after immediate implant placement and provisionalization (IIPP) with thin buccal plate phenotype in the anterior maxilla. Materials and methods: Patients requiring IIPP of single maxillary incisor with thin buccal bone plate (<1 mm) were recruited. Cone‐beam computed tomography (CBCT), performed before and 6 months after the intervention, were three‐dimensionally superimposed. A virtual line connecting the bony emergence points of adjacent teeth was drawn as a reference. The facial–coronal alveolar crest of the extraction socket and healed ridge were located in mesial, middle and distal cross‐sectional planes, and linear ridge reductions were measured. The correlation between ridge reduction and local factors was analyzed. Results: Fifty patients were included. From the extraction socket to healed ridge, the alveolar crest underwent linear bone reduction of 1.50 ± 0.50, 1.54 ± 0.66 and 1.65 ± 0.73 mm in the mesial, middle, and distal regions in an apical–palatal direction. The middle region had significantly higher horizontal (facial–palatal) but lower vertical (coronal–apical) bone reduction than the mesial and distal areas (P < 0.01). The facial–coronal ridge crest of the healed ridge located close to the reference line. Ridge reduction positively correlated with the distance between the initial facial–coronal crest of the extraction socket and the reference line (P < 0.01). Conclusions: Alveolar crest of the socket lost its curvature and tended to attain a flat profile after IIPP due to inconsistent ridge reduction in middle, mesial and distal areas. The reference line may be a potential landmark for predicting the ridge crest after remodeling. [ABSTRACT FROM AUTHOR]

Purpose: To assess the clinical performance of screw‐retained, ceramic‐veneered, monolithic zirconia partial implant‐supported fixed dental prostheses (ISFDP) over 5–10 years and to evaluate implant‐ and prosthesis‐related factors influencing treatment failure and complications. Materials and methods: Partially edentulous patients treated with screw‐retained all‐ceramic ISFDPs with 2–4 prosthetic units with a documented follow‐up of ≥5 years after implant loading were included in this retrospective study. The outcomes analyzed included implant/prosthesis failure and biological/technical complications. Possible risk factors were identified using the mixed effects Cox regression analysis. Results: A screened sample of 171 participants with 208 prostheses (95% of the restorations were splinted crowns without a pontic) supported by 451 dental implants were enrolled in this study. The mean follow‐up duration after prosthesis delivery was 82.4 ±17.2 months. By the end of the follow‐up period, 431 (95.57%) of the 451 implants remained functional at the implant level. At the prosthesis level, 185 (88.94%) of the 208 partial ISFDPs remained functional. Biological complications were observed in 67 implants (14.86%), and technical complications were observed in 62 ISFDPs (29.81%). Analysis revealed only emergence profiles (over‐contoured) as a significant risk factor for implant failure (P<0.001) and biological complications (P<0.001). Full‐coverage ceramic‐veneered zirconia prostheses had a significantly greater chance of chipping (P<0.001) compared with buccal‐ceramic‐veneered or monolithic zirconia prostheses. Conclusions: Screw‐retained ceramic‐veneered, monolithic partial ISFDPs have a favorable long‐term survival rate. Over‐contoured emergence profile is a significant risk factor associated with implant failure and biological complications. Buccal‐ceramic‐veneered and monolithic zirconia partial ISFDPs lower the initial prevalence of chipping compared with a full‐coverage veneered design. [ABSTRACT FROM AUTHOR]