Research Appraisals
Evidence-based critical appraisals of the latest medical research, systematically evaluated using Oxford CEBM methodology.
Showing 6 appraisals
Journal of prosthodontic research
Peri-implant soft-tissue responses to tooth-colored abutment materials: A systematic review.
PURPOSE: This systematic review aimed to investigate and compare peri-implant soft-tissue responses to tooth-colored abutment materials frequently used in implant dentistry. STUDY SELECTION: A comprehensive electronic search was performed in three databases (MEDLINE via PubMed, Google Scholar, and Scopus) to identify relevant literature. The study-selection criteria included original research articles written in English that investigated the effects of various tooth-colored abutment materials on peri-implant soft-tissue responses. RESULTS: In total, 136 articles were included in this systematic review. Tooth-colored abutment materials, particularly zirconia and polyetheretherketone (PEEK), facilitated favorable soft-tissue adaptation, enhanced esthetics, and contributed to long-term implant success. Zirconia demonstrated excellent biocompatibility, enhanced cell viability and attachment, and lower inflammatory responses compared to titanium, suggesting improved soft-tissue integration and reduced biofilm-related risks. PEEK exhibited favorable mechanical properties and biocompatibility but limited cell attachment due to its hydrophobicity, indicating the need for surface modification. Titanium remains the clinical standard for integration but is associated with greater inflammation and biofilm formation than tooth-colored materials. CONCLUSIONS: This review highlights the effects of tooth-colored abutment materials on peri-implant soft-tissue responses and emphasizes the importance of selecting appropriate materials for successful dental implants. Zirconia represents a promising biological alternative to titanium, promoting a stable soft-tissue barrier that contributes to minimizing inflammation and maintaining long-term tissue health. Conversely, while PEEK offers strong mechanical properties, it faces challenges regarding cell proliferation and matrix production, limiting its optimal biological performance. Further research will provide deeper insights into the best options for enhancing patient and esthetic outcomes.
14 July 2026
Read appraisal →Operative dentistry
Color Match of Single-Shade and Group-Shade Resin Composites: A Visual and Instrumental Analysis
OBJECTIVE: Single-shade materials are favored for simplifying clinical workflows without compromising the esthetics of restorations, although evidence supporting their use remains limited. Therefore, this laboratory evaluated color match of single-shade versus group-shade resin composites. METHODS: Sixty sound human molars were divided into three subgroups (n = 20), based on the tooth-shade correspondence for the tested group-shade resin composite: L (light) including A1, B1, B2, C1 and D2; M (medium) including A2, A3, C2, D3 and D4, and D (dark) including A3.5, A4, B3, B4, C3 and C4 shaded teeth. Standardized class V cavities (4 × 4 × 2 mm) were prepared. Half of the specimens within each subgroup were restored with single-shade (Omnichroma), while the other half was restored with group-shade resin composite (SimpliShade). Tooth/restoration ΔE00 color differences were calculated at 24 hours (T1), and after seven days (T2) by a spectrophotometer (VITA Easyshade V). A visual analysis was performed after 14 days (T3). Also, a novel computer vision algorithm (CVA) analysis, was employed to evaluate color match at three weeks (T4). Student's t-test was used to compare the two groups within each subgroup and time point and one-way ANOVA was used to compare the values between subgroups, within each group and time point. RESULTS: Instrumental analysis at T1 showed higher mean ΔE00 for single-shade compared to group-shade resin composites (p < 0.05), within each subgroup. Within single-shade specimens, significantly higher mean ΔE00 differences were found at T2 between D (8.24 ± 1.85) vs L (5.65 ± 2.24) (p = 0.007) and M (6.49 ± 2.5) (p = 0.03). Within group-shade specimens, a significant difference was found between L (4.16 ± 2.19) and M (2.17 ± 1.05) at T1 (p = 0.034). Visual analysis reported a significant difference (p = 0.0153) between L-group shade (1.03 ± 1.04) and L-single shade (1.97 ± 0.78) restorations (p = 0.0153). No significant differences were detected when CVA analysis was employed. CONCLUSIONS: Overall, group-shade showed better color match than single-shade resin composites, especially when spectrophotometric and visual evaluation were employed.
11 June 2026
Read appraisal →The International journal of prosthodontics
A Systematic Review and Meta-analysis Evaluating the Survival, Failure, and Complication Rates of Metal-Ceramic, Veneered, and Monolithic All-Ceramic Tooth-Supported Single Crowns-Part 1
PURPOSE: To evaluate five-year survival rates of metal-ceramic, veneered all-ceramic, and monolithic all-ceramic tooth-supported single crowns (SCs) and assess biological and technical complications. MATERIALS AND METHODS: A systematic search of Medline (PubMed), Embase, and CENTRAL (2014-2024) identified clinical studies on tooth-supported fixed dental prostheses (≥3 years mean follow-up). Manual screening and 30 studies from previous reviews were added. Sixty-four studies met inclusion, reporting on 3,509 metal-ceramic and 8,051 all-ceramic SCs. Robust Poisson regression models were used to estimate pooled five-year survival rates. RESULTS: Twelve studies investigated metal-ceramic crowns, 49 all-ceramic crowns, and three both. Five-year survival rates were: 98.5% for monolithic lithium-disilicate reinforced glass-ceramic, 97.3% for veneered densely-sintered zirconia, 97.1% for metal-ceramic, 96.8% for monolithic densely-sintered zirconia, 95.7% for veneered leucite/lithium-disilicate reinforced glass-ceramic, 94.5% for densely-sintered alumina, 94.3% for glass-infiltrated alumina, 90.4% for feldspathic/silica-based ceramic. Survival rates of feldspathic/silica-based ceramic (P<0.0001), glass-infiltrated alumina (P=0.019), densely sintered alumina (P=0.002), and veneered leucite/lithium-disilicate reinforced glass-ceramic (P=0.021) were significantly lower than monolithic lithium-disilicate SCs. Except for feldspathic/silica-based ceramic and metal-ceramic crowns, material/design types performed similarly in anterior and posterior regions. Monolithic lithium-disilicate and monolithic zirconia crowns showed significantly fewer ceramic fractures and chipping compared to veneered alternatives. CONCLUSIONS: Lithium-disilicate and zirconia-based all-ceramic SCs achieve five-year survival rates comparable to metal-ceramic crowns. Monolithic designs reduce fracture and chipping risk, improving long-term clinical outcomes.
28 May 2026
Read appraisal →Clinical oral investigations
Clinical performance of alkasite and glass-hybrid restorations compared with resin composite in class II cavities: a randomized clinical trial
OBJECTIVES: The aim of this randomized clinical trial was to evaluate the 18-month clinical performance of alkasite and glass-hybrid restorations compared with resin composite in Class II restorations. MATERIALS AND METHODS: A total of 50 patients requiring at least three Class II restorations in premolar and molar teeth were recruited. Each patient received three restorations, which were randomly assigned to one of the following materials: an alkasite (Cention N, Ivoclar Vivadent), a glass-hybrid (Equia Forte HT, GC Corp.), or a resin composite (Gradia Direct Posterior, GC Corp.). Alkasite and glass-hybrid served as test groups while resin composite served as the control group. During the 18-month follow-up, restorations were scored at baseline, 6, 12, and 18 months using the FDI criteria. Data were analyzed using the Chi-square and Cochran's Q tests (α = 0.05). RESULTS: No significant differences were detected among the groups for esthetic, functional, or biological criteria over 18 months (p > 0.05). Regarding esthetic properties, the control group showed 100% success for all esthetic criteria at all recall visits, while the alkasite group maintained a 96% success rate at all time points, and glass-hybrid showed 98% success at 6 and 12 months and 92% at 18 months. Minor score-2 changes in color match and gloss were detected in the glass-hybrid and alkasite groups but were not significant (p > 0.05). For functional and biological outcomes, all groups achieved 100% success rates for all evaluated parameters. CONCLUSIONS: Alkasite and glass-hybrid groups exhibited clinical performance comparable to resin composite over the 18-month follow-up in Class II cavities. All materials demonstrated excellent functional and biological stability while achieving clinically acceptable aesthetic results.
10 May 2026
Read appraisal →Journal of prosthodontic research
Flexural strength of translucent zirconia for single crowns and fixed dental prostheses-A systematic review
PURPOSE: The aim of this systematic review was to analyze the reported flexural strength values of commercially available translucent zirconia materials. Additionally, data were evaluated to assess the impact of different specimen preparations and test methods. STUDY SELECTION: This systematic review was conducted according to the PRISMA guidelines. Electronic searches were performed to identify in vitro studies published between January 1, 2013, and March 15, 2025, that reported flexural strength values of translucent zirconia and included the names of the tested materials and manufacturers. Flexural strength values were analyzed to assess the effects of yttria content, specimen processing, surface treatments, and test methods using Kruskal-Wallis analysis of variance (α = 0.05) and forest plots. RESULTS: A total of 78 laboratory studies met the inclusion criteria. The overall flexural strength values were significantly higher for 4Y-PSZ (803± 233 MPa) than for 5Y-PSZ materials (570 ± 116 MPa) (P = 0.005). Specimen processing, surface treatments, and test methods significantly affected the flexural strength values for 5Y-PSZ (P < 0.001) but not for 4Y-PSZ (P > 0.05). CONCLUSIONS: This systematic review highlights the challenges in comparing the flexural strength values of translucent zirconia owing to differences in processing parameters. Further standardization of test methods and adherence to ISO 6872 would improve comparability. Our findings support the clinical use of 4Y-PSZ for three-unit fixed dental prostheses (FDPs) and 5Y-PSZ for three-unit FDPs in the anterior region based on ISO 6872.
13 Apr 2026
Read appraisal →Journal of prosthodontic research
Cleaning methods of contaminated lithium disilicate ceramics: A systematic review and network meta-analysis
PURPOSE: To evaluate the effects of various cleaning methods on the bond strength between lithium disilicate (LS2) ceramics and resin cement under short- and long-term aging conditions using network meta-analysis (NMA) and pairwise meta-analysis (PMA). STUDY SELECTION: An electronic search of seven databases (PubMed, Scopus, Embase, Web of Science, Google Scholar, Defense Technical Information Center, and LILACS) with a manual search of the reference lists was conducted for articles published up to March 10, 2025. Eligible studies included those that assessed the bond strength of LS2, either uncontaminated or contaminated with human saliva, fit-checking materials, try-in paste, or their combinations, using different cleaning methods. Risk of bias was evaluated using the RoBDEMAT tool. A frequentist multivariable random-effects model was used to calculate the effect sizes. RESULTS: Fifteen studies met the inclusion criteria. Under short-term aging conditions, NMA showed higher bond strengths in the uncontaminated LS2 group and the contaminated groups cleaned with hydrofluoric acid etching, commercial ceramic cleaning agents, or phosphoric acid etching than those uncleaned or cleaned with water or alcohol. In long-term aging, PMA and NMA exhibited higher bond strengths in the uncontaminated LS2 group and contaminated group cleaned with phosphoric acid etching than those contaminated groups cleaned with water or alcohol. CONCLUSIONS: Phosphoric acid etching effectively eliminates contaminants, whereas the application of water or alcohol is ineffective. Although ceramic cleaning agents effectively decontaminate surfaces under short-term aging conditions, their performance deteriorates over time, potentially compromising long-term bond durability.
13 Apr 2026
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