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High-performance polymers including polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) have been used as substitutes for metal frameworks in dental prostheses. However, the clinical performance of polymer-based frameworks is still uncertain. The purpose of this systematic review was to compare the clinical performance of PEEK and PEKK with that of metal frameworks for different dental prostheses. This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six databases and non–peer-reviewed literature (without language or follow-up restrictions) were searched for studies conducted before February 2022. Only clinical studies, either randomized clinical trials (RCTs) or nonrandomized clinical trials (N-RCTs), comparing the clinical performance of polymer and metal frameworks were included. The risk of bias and certainty of the evidence were assessed with the RoB 2.0, ROBINS-I, and GRADE. Biologic (plaque and gingival indices, probing depth, bleeding scores, implant stability quotient, marginal bone loss) and mechanical outcomes (ridge base relation, prosthetic marginal gap, and fracture) were assessed. Only 9 studies (7 RCTs and 2 N-RCTs) were included, all with moderate to serious risk of bias and low to very low certainty of evidence. No meta-analysis was possible, but qualitative analysis revealed lower plaque and gingival indices, probing depth, and marginal bone loss, with higher survival rates for implant-supported fixed prostheses and overdentures fabricated with PEEK than for metal frameworks. No significant differences were found between groups for removable partial dentures. The marginal fit of PEEK frameworks was also better for single crowns. Three fractures were reported in the 3 PEKK fixed dental prostheses with cantilevers. PEEK and PEKK seem to be promising materials for dental prostheses, with acceptable response from the periodontal tissue. However, further well-designed studies are necessary to better understand their clinical and long-term limitations. [ABSTRACT FROM AUTHOR]

Statement of Problem: Staining at the gingival margin could impact denture longevity, but the behavior of gingival colored composite resins (GCCs) in this area remains unclear., Purpose: This in vitro study evaluated surface staining, microleakage, and push-out bond strength at the gingival margin of artificial teeth, comparing two consistencies of GCCs with two resin base materials., Material and Methods: Specimens included artificial teeth (Ivostar; Ivoclar AG) and two acrylic resin base materials: conventional (Ondacryl; Clássico) and high-impact (Diamond D; Keystone Industries) (n=300). Specimens were divided in three groups: control (acrylic resin) and experimental groups, receiving one of the two GCCs consistencies: paste (SR Nexco; Ivoclar AG) or flowable (Gradia Plus Gum; GC Europe)). Initial artificial aging treatment in distilled water (5 days at 55º C) was performed and the specimens were then immersed in 5% methylene blue dye or coffee for 7 days at 37º C. Staining was visually assessed, and the specimens were sectioned for dye infiltration analysis at the gingival margin using a stereomicroscope. Bond strength was measured with the push-out test in the gingival colored composite resin specimens. Data were analyzed using 2-way and 3-way ANOVA with Bonferroni post hoc test and Kruskal-Wallis test with Dunn post hoc test (α=.05)., Results: A significantly higher surface staining and microleakage was observed in experimental groups compared to the control (acrylic resin) (P<.001). Surface staining revealed that paste consistency GCC was more susceptible to discoloration in coffee, while flowable GCC was more affected by methylene blue. Lower microleakage values were observed in the control (acrylic resin) groups (0.11 ±0.13 mm for the conventional base and 0.08 ±0.11 mm for the high-impact base) in comparison with the experimental groups (P<.05). The flowable GCC showed the highest microleakage with methylene blue (0.98 ±0.21 mm for the conventional base and 0.91 ±0.31 mm for the high-impact base), significantly greater than the paste consistency for both base materials (0.53 ±0.22 mm for the conventional base and 0.66 ±0.34 mm for the high-impact base; P<.001). For coffee immersion, both GCC consistencies displayed similar microleakage values (P>.05). Push-out bond strength was comparable between paste and flowable GCCs (P>.05)., Conclusions: Microleakage at the gingival margin was significantly greater when GCC was applied, regardless of the consistency. However, the GCC consistency seems to not affect push-out bond strength. Further clinical studies are needed to better understand the impact of these findings on prosthesis longevity., (Copyright © 2025 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: The long-term effects of wearing removable partial dentures (RPDs) remain unclear., Purpose: This systematic review addressed the question "Is the long-term use of RPDs deleterious to the remaining teeth?", Material and Methods: This review was guided by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist. Six databases and nonpeer-reviewed literature were searched in April 2024 without language or follow-up restrictions. Only clinical studies evaluating RPD long-term use were included. The risk of bias and evidence certainty were assessed (RoB 2.0; ROBINS-I; GRADE), and meta-analyses were conducted for survival rate and periodontal health (α=.05)., Results: A total of 5577 records were identified, and 46 studies covering data from 4359 prostheses and 4072 participants (mean age 60 ±5.2 years) were included. A low to moderate risk of bias was found. A 5-year survival rate of 95.1% (ER=0.951; 95% CI=0.900 to 0.977; P<.001) and 91.7% (ER=0.917; 95% CI=0.870 to 0.948; P<.001) was found for cast-clasp RPD and RPDs retained by telescopic crowns respectively, with no difference between them (P=.71). Abutments (OR=1.99, 95% CI=1.32 to 3.01; P=.001) and nonvital teeth (HR=2.961; 95% CI=2.023 to 4.335; P<.001) presented a higher risk of extraction after 5 years. Tooth mobility (P=.98) and probing depth (P=.50) remained unchanged, while the gingival index increased (MD=0.477 (95% CI=0.12 to 0.83; P=.008)., Conclusions: A high survival rate was found for both cast-clasp RPD and RPDs retained by telescopic crowns, with few periodontal changes to the remaining teeth., (Copyright © 2024 Editorial Council for The Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)