Browsing by Author "Silva, Filipe"
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- Dry-aged beef: a global review of meat quality traits, microbiome dynamics, safety, and sustainable strategiesPublication . Ribeiro, Ana J.; Silva, Filipe; Teixeira, Paula; Saraiva, Cristina M.Dry-aged beef is valued for its tenderness, complex aroma, and concentrated flavor. However, variability in aging protocols and limited understanding of underlying biological and technological processes can compromise consistent quality and safety. This review examines factors influencing meat characteristics, including genetics, breed, sex, age, diet, intramuscular fat deposition, antioxidant reserves, and endogenous enzyme pools. Postmortem biochemical pathways, such as proteolysis, lipid oxidation, and nucleotide degradation, are discussed in relation to flavor and texture development. The dynamics of surface microbiota are analyzed, highlighting the succession from psychrotrophic spoilage bacteria to molds and yeasts, which collectively form an enzymatic crust that contributes umami and nutty notes while providing antimicrobial barriers. Regulatory frameworks in major markets are reviewed, alongside valorization strategies that convert crust trimmings into umami-rich powders, bioactive peptides, starter cultures, or industrial enzymes. Despite advances, critical knowledge gaps remain, including the functional roles of minor crust taxa, the efficacy of defined starter cultures or bacteriophage blends, and standardized methods for texture and flavor measurement. By focusing on these biochemical and microbiological mechanisms and their applications, this review provides a roadmap for transforming dry aging into a reproducible, safe, and high-quality process in modern meat science.
- Fitting of different intraradicular composite posts to oval tooth root canals: a preliminary assessmentPublication . Fernandes, Valter; Fidalgo-Pereira, Rita; Edwards, Jane; Silva, Filipe; Özcan, Mutlu; Carvalho, Óscar; Souza, Júlio C. M.The purpose of the present study was to perform a preliminary analysis of the fitting of different fiber-reinforced composite (GFRC) posts to tooth root canals and determine the resin cement layer thickness. The following GFRC posts were assessed: bundle posts (Rebilda GTTM, VOCO, Germany), sleeve system (SAPTM, Angelus Ind, Brazil), and accessory posts (ReforpinTM, Angelus, Brazil). Twenty-four freshly extracted mandibular single-rooted pre-molars were endodontically treated and divided into six groups, according to the type of GFRC post and resin cement (self-adhesive or conventional dual-cured). Then, specimens were cross-sectioned and inspected by optical microscopy regarding the cement layer thickness and presence of defects such as pores, voids, or fissures were assessed. Bundle and accessory posts revealed a regular distribution of resin cement with a lower number of voids than found with sleeve systems. The sleeve system posts showed poor fitting at the apical portion of the root canals. The type of resin cement did not affect the thickness of the interface, although both bundle and accessory posts allow a better distribution of resin cement and fibers. The present preliminary study reveals interesting insights on the fitting of bundle and accessory posts to root dentin and resin cement layer thickness in oval-shape root canals. The sleeve system posts showed adequate fitting only at the coronal portion of the canals.
- Laser-texturing and traditional surface modification to improve the adhesion of glass fiber-reinforced composite posts to resin cementsPublication . Fernandes, Valter; Carvalho, Oscar; Silva, Filipe; Henriques, Bruno; Özcan, Mutlu; Souza, Júlio C. M.Objectives The aim of this study was to perform experimental evaluation of the synergistic effects of laser-texturing and different traditional surface modification approaches to improve the push-out bond strength of glass fiber-reinforced composite (GFRC) posts to resin-matrix cements used in endodontically treated teeth rehabilitation. Methods One hundred and ten freshly extracted mandibular single-rooted premolars were endodontically treated and groups of specimens were divided according to the GFRC cementation after different surface treatment, as follow (n = 10): silane-based conditioning (SIL); 9.7 % HF acid-etching (HF); 35 % H2O2 etching (H2O2); grit-blasting (GB); HF plus H2O2 etching (HFH2O2); 6 W Nd:YAG laser-texturing (L6W); 4.5 W Nd:YAG laser-texturing (L4.5W); 3 W Nd:YAG laser-texturing (L3W); 3 W Nd:YAG plus 35 % H2O2 (L3WH2O2); 3 W Nd:YAG plus SIL (L3WSIL); and no-treatment (C). GFRC posts were cemented into the tooth root canals using a dual-cured resin cement. Then, specimens were cross-sectioned and mechanically assessed by push-out bond strength tests. Specimens were inspected by optical microscopy and scanning electron microscopy at magnification from × 30 up to × 2000. Data were analyzed using one-way analysis of variance and Tukey post hoc test (p = 0.05). Results Surface analyses of the GFRC posts showed a rough and retentive morphological aspect with a removal of the outer epoxy matrix layer and exposure of glass fibers after laser-texturing, grit-blasting or etching under 35 % H2O2. The highest bond strength values at 21.8 MPa was recorded for GFRC posts after laser-texturing on 3W plus silane-based conditioning followed by the group etched with 35 % H2O2 (20.5 MPa). The failure mode was characterized as cohesive and mixed pathways. The lowest bond strength values around 5 and 9 MPa were recorded for untreated GFRC surfaces or specimens etched with HF that was noticeable by adhesive failure pathways. Conclusions The combination of acidic etching and silane conditioning with laser-texturing at medium intensity promoted an adequate surface modification of GFRC posts and increased adhesion to a resin-matrix cement. Such combination of physicochemical approaches can enhance the long-term mechanical behavior of the restorative interface at endodontically treated teeth. Clinical relevance Combining traditional and novel physicochemical approaches can provide promising adhesion pathways for glass fiber-reinforced composite posts to resin-matrix cements. A high mechanical interlocking of the resin-matrix cements and stable retention of the teeth root intracanal posts can decrease the risks of clinical failures by fracture and detachment of the adhesive interface.
- Microbial, physicochemical profile and sensory perception of dry-aged beef quality: a preliminary Portuguese contribution to the validation of the dry aging processPublication . Ribeiro, Ana; Oliveira, Irene; Soares, Kamila; Silva, Filipe; Teixeira, Paula; Saraiva, CristinaBeef dry-aging consists of a selection of unpackaged prime cuts placed in a controlled environment cold room for several weeks. The goals are to concentrate flavors like nutty and beefy and to improve tenderness. The aim of this study was to verify the microbiological and physicochemical behavior and sensory perception of meat during a sample process example of meat dry-aging. Twelve beef loins were selected for 90 days of dry aging and placed in a cold room with average temperature, relative humidity and forced air 3.2 ± 0.7 °C, 60.7 ± 4.2% and 0.5–2 m/s, respectively. Samples of crust and lean meat were collected on days 1, 14, 21, 35, 60 and 90 of the dry aging process for microbiological, physicochemical (pH, aw, color L*a*b*) and sensory analysis. During drying, no pathogenic bacteria were detected, and the average counts were higher for the crust. The average values for water activity (aw) and pH were 0.98 ± 0.02 and 5.77 ± 0.015, respectively. A slight decrease in aw and an increase in pH were observed over the aging period (p < 0.05). The lower microbial counts on the lean meat and the overall assessment of freshness confirm the importance of good manufacturing and storage practices during dry aging.
- Mineral profile, oxidative stability and color traits in dry aged meat: integrative analysisPublication . Ribeiro, Ana J.; Braga, Fernando G.; Oliveira, Irene; Silva, Filipe; Teixeira, Paula; Saraiva, Cristina M.Dry aging enhances beef's sensory quality, but the role of trace-element dynamics in driving physicochemical changes remains unclear. We dry-aged Longissimus lumborum loins (n = 12) for 60 days, sampling on days 1, 14, 35 and 60. Essential (Ca, K, Na, Mg, Fe, Se, Cr, Zn, Cu) and toxic (As, Cd, Co, Pb) elements were quantified by GF-AAS/FAAS; pH and L?, a?, b? color were measured with standard probes; lipid oxidation was assessed via TBARS; and myoglobin redox forms were determined spectrophotometrically. Inner muscle consistently retained higher K, Na, Mg, Zn, Cu and Cr compared to the crust (P < 0.01), reflecting diffusive retention during surface desiccation. Over 60 days, Ca, K, Se and Cr increased (P < 0.01) while Na and Mg decreased (P < 0.001). Iron and zinc exhibited a biphasic pattern, declining to day 35 and rebounding by day 60. Lipid oxidation intensified but remained below sensory rancidity thresholds (TBARS increased from 0.25 ± 0.07 to 0.65 ± 0.33 mg MDA/kg in inner meat and from 0.79 ± 0.15 to 1.53 ± 0.36 mg MDA/kg in crust; P < 0.001), concurrent with a pH rise from 5.61 ± 0.09 to 5.80 ± 0.19 (P < 0.001) and declines of approximately 11 % in redness (a?) and 15 % in yellowness (b?) (P < 0.01). Principal component analysis identified an oxidation-mineral-color gradient (PC1, 30.8 % variance) and a myoglobin-redox axis (PC2, 20.4 %), underscoring mechanistic links between trace element fluctuations, lipid oxidation, and color stability. These results demonstrate that dry aging concentrate minerals and that shifts in Fe, Se, and Zn trajectories modulate oxidative stability, pH drift, and pigment transformations, shaping dry-aged beef color and overall quality.
- Morphological aspects and distribution of granules composed of deproteinized bovine bone or human dentin into a putty mixture: an in vitro studyPublication . Pimentel, Inês; Henriques, Bruno; Silva, Filipe; Carvalho, Oscar; Teughels, Wim; Özcan, Mutlu; Souza, Júlio C. M.Objective: The main aim of this study was to evaluate the morphological aspects and distribution of granules composed of deproteinized bovine bone mineral (DBBM) and human dentin-derived bone graft (HDBG) into a putty consistency mixture. Materials and methods: DBBM or HDBG were mixed with an alginate-based hydrogel at two different granule/hydrogel ratio (1:1 and 1:3) and divided into four test groups while two control groups were composed of DBBM or HDBG free of hydrogel. Groups of specimens were cross-sectioned for morphological evaluation by scanning electron microscopy (SEM) at backscattered electrons mode. Details on the dimensions and pores’ size of DBBM and HDBG were evaluated after mixing different amounts of particles and alginate-based hydrogels. Results: Microscopic analyses revealed a size of DBBM granules ranging from 750 up to 1600 μm while HDBG particles showed particle size ranging from 375 up to 1500 μm. No statistical differences were identified regarding the size of granules (p > 0.5). The mean values of pores’ size of DBBM particles were noticed at around 400 μm while HDBG particles revealed micro-scale pores of around 1–3 μm promoted by the dentin tubules (p < 0.05). The lowest distance between particles was at 125 μm for HDBG and 250 μm for DBBM when the particle content was increased. On decreasing the particles’ content, the distance between particles was larger for DBBM (~ 1000 μm) and HDBG (~ 1100 μm). In fact, statistically significant differences were found when the content of granules increased (p < 0.05). Conclusions: The increased content of bioactive ceramic granules in a putty consistency mixture with hydrogel decreased the space among granules that can promote a high ceramic density and stimulate the bone growth over the healing process. Macro-scale pores on bovine bone mineral granules stimulate the formation of blood vessels and cell migration while the micro-scale pores of dentin-derived granules are proper for the adsorption of proteins and growth of osteogenic cells on the bone healing process. Clinical significance: A high amount of bioactive ceramic granules should be considered when mixing with hydrogels as a putty material since that result in small spaces among granules maintaining the bone volume over the bone healing process. Deproteinized bovine bone mineral granules have macro-scale pores providing an enhanced angiogenesis while dentin-derived granules possess only micro-scale pores for the adsorption of proteins and proliferation of osteogenic cells on the bone healing process. Further studies should evaluate the combination of different bioactive ceramic materials for enhanced bone healing.
- Short-pulse direct laser writing of 3Y-TZP zirconia: a superior surface modification strategy for enhanced resin bonding and adhesion durabilityPublication . Sahoo, Narayan; Carvalho, Óscar; Özcan, Mutlu; Eyüboğlu, Tan Fırat; Souza, Júlio C. M.; Silva, Filipe; Henriques, BrunoThe clinical success of zirconia-based restorations relies on surface modifications that enhance adhesion without compromising material integrity. This study evaluates Direct Laser Writing (DLW) as a non-contact, contamination-free alternative to conventional grit-blasting methods (alumina particle abrasion [SB] and silica-coated alumina treatment [SC]. Surface roughness (Ra), wettability, surface free energy (SFE), phase transformation, and shear bond strength (SBS) were assessed. Zirconia specimens (N = 40) underwent DLW at two distinct parameters (DLW35, DLW10) or conventional grit-blasting (SB, SC). Surface characterization included roughness measurements, contact angle analysis, and SFE calculation (Owens-Wendt method). Phase transformation was quantified using X-ray diffraction (XRD). SBS tests between zirconia and resin-matrix cement were performed under water storage and thermocycled conditions. Results showed DLW provided controlled, uniform roughness comparable to grit-blasting without inducing mechanical damage or contamination. DLW-treated surfaces exhibited significantly better wettability and higher SFE. SBS values were statistically similar across all groups, indicating stable adhesion performance under both dry and thermocycled conditions. DLW preserved the tetragonal zirconia phase substantially better (DLW35: 93 %, DLW10: 85 %) compared to grit-blasted surfaces (SB: 76 %, SC: 68 %), minimizing residual stress and microstructural damage. The study concludes DLW is a superior zirconia surface treatment, offering precise control, contamination-free surfaces, enhanced wettability, and maintained microstructural integrity, making it ideal for dental, maxillofacial, and orthopedic applications.