Multivalent hydrogen-bonded architectures directed by self-complementarity between [Cu(2,2'-biimidazole)] and malonate building blocks.

The synthesis and structural characterization of four novel supramolecular hydrogen-bonded arrangements based on self-assembly from molecular `[Cu(2,2'-biimidazole)]' modules and malonate anions are presented, namely, tetrakis(2,2'-biimidazole)di-µ-chlorido-dimalonatotricopper(II) pentahydrate, [Cu3(C3H2O4)2Cl2(C6H6N4)4]·5H2O or [Cu(H2biim)2(µ-Cl)Cu0.5(mal)]2·5H2O, aqua(2,2'-biimidazole)malonatocopper(II) dihydrate, [Cu(C3H2O4)(C6H6N4)(H2O)]·2H2O or [Cu(H2biim)(mal)(H2O)]·2H2O, bis[aquabis(2,2'-biimidazole)copper(II)] dimalonatodiperchloratocopper(II) 2.2-hydrate, [Cu(C6H6N4)2(H2O)]2[Cu(C3H2O4)(ClO4)2]·2.2H2O or [Cu(H2biim)2(H2O)]2[Cu(mal)2(ClO4)2]·2.2H2O, and bis(2,2'-biimidazole)copper(II) bis[bis(2,2'-biimidazole)(2-carboxyacetato)malonatocopper(II)] tridecahydrate, [Cu(C6H6N4)2][Cu(C3H2O4)(C3H3O4)(C6H6N4)2]·13H2O or [Cu(H2biim)2][Cu(H2biim)2(Hmal)(mal)]2·13H2O. These assemblies are characterized by self-complementary donor-acceptor molecular interactions, demonstrating a recurrent and distinctive pattern of hydrogen-bonding preferences among the carboxylate, carboxylic acid and N-H groups of the coordinated 2,2'-biimidazole and malonate ligands. Additionally, coordination of the carboxylate group with the metallic centre helps sustain remarkable supramolecular assemblies, such as layers, helices, double helix columns or 3D channeled architectures, including mixed-metal complexes, into a single structure.

Effect of hydrofluoric acid and self-etch ceramic primers on the flexural strength and fatigue resistance of glass ceramics: A systematic review and meta-analysis of in vitro studies.

This systematic review evaluated the effect of different hydrofluoric acid (HF) etching regimens and a self-etch ceramic primer (SECP) on the flexural strength (FS) and fatigue failure load (FFL) of glass-ceramic materials.The identification of relevant studies was conducted by two authors in five databases: PubMED, Scopus, Web Of Science, LILACS and Virtual Health Library (BVS) until July 2022 with no year limit. The analysis was conducted in RevMan 5.4.1 Software (Cochrane Collaboration) using Random effect model at 5 %. The risk of bias of the included studies were assessed. From the 5349 articles identified, 34 were included for quantitative analysis. Meta-analysis showed that for predominantly glassy ceramics, etching with HF 5 % had no significant impact on FS, however, HF acid etching with concentrations greater than 5 % negatively impacted FS. For lithium disilicate glass-ceramics (LDGC) HF acid etching, negatively influenced FS, while increasing the FFL. HF etching negatively affected FS of hybrid ceramics. The self-etch ceramic primer and HF acid etching showed a similar impact on FFL and FS. This meta-analysis indicates that the impact of SECP and HF acid etching on the mechanical behavior of glass ceramics is material-dependent.

Exploration of Free Energy Surface of the Au10 Nanocluster at Finite Temperature.

The first step in comprehending the properties of Au10 clusters is understanding the lowest energy structure at low and high temperatures. Functional materials operate at finite temperatures; however, energy computations employing density functional theory (DFT) methodology are typically carried out at zero temperature, leaving many properties unexplored. This study explored the potential and free energy surface of the neutral Au10 nanocluster at a finite temperature, employing a genetic algorithm coupled with DFT and nanothermodynamics. Furthermore, we computed the thermal population and infrared Boltzmann spectrum at a finite temperature and compared it with the validated experimental data. Moreover, we performed the chemical bonding analysis using the quantum theory of atoms in molecules (QTAIM) approach and the adaptive natural density partitioning method (AdNDP) to shed light on the bonding of Au atoms in the low-energy structures. In the calculations, we take into consideration the relativistic effects through the zero-order regular approximation (ZORA), the dispersion through Grimme's dispersion with Becke-Johnson damping (D3BJ), and we employed nanothermodynamics to consider temperature contributions. Small Au clusters prefer the planar shape, and the transition from 2D to 3D could take place at atomic clusters consisting of ten atoms, which could be affected by temperature, relativistic effects, and dispersion. We analyzed the energetic ordering of structures calculated using DFT with ZORA and single-point energy calculation employing the DLPNO-CCSD(T) methodology. Our findings indicate that the planar lowest energy structure computed with DFT is not the lowest energy structure computed at the DLPN0-CCSD(T) level of theory. The computed thermal population indicates that the 2D elongated hexagon configuration strongly dominates at a temperature range of 50-800 K. Based on the thermal population, at a temperature of 100 K, the computed IR Boltzmann spectrum agrees with the experimental IR spectrum. The chemical bonding analysis on the lowest energy structure indicates that the cluster bond is due only to the electrons of the 6 s orbital, and the Au d orbitals do not participate in the bonding of this system.

Ru(II)-Catalyzed Asymmetric Transfer Hydrogenation of α-Alkyl-ß-Ketoaldehydes via Dynamic Kinetic Resolution.

The (R,R)-Teth-TsDPEN-Ru(II) complex promoted the one-pot double C=O reduction of α-alkyl-ß-ketoaldehydes through asymmetric transfer hydrogenation/dynamic kinetic resolution (ATH-DKR) under mild conditions. In this process, ten anti-2-benzyl-1-phenylpropane-1,3-diols (85:15 to 92:8 dr) were obtained in good yields (41-87%) and excellent enantioselectivities (>99% ee for all compounds). Notably, the preferential reduction of the aldehyde moiety led to the in situ formation of 2-benzyl-3-hydroxy-1-phenylpropan-1-one intermediates. These intermediates played a crucial role in enhancing both reactivity and stereoselectivity through hydrogen bonding.

Using cocrystals as a tool to study non-crystallizing molecules: crystal structure, Hirshfeld surface analysis and computational study of the 1:1 cocrystal of (E)-N-(3,4-difluorophenyl)-1-(pyridin-4-yl)methanimine and acetic acid.

Using a 1:1 cocrystal of (E)-N-(3,4-difluorophenyl)-1-(pyridin-4-yl)methanimine with acetic acid, C12H8F2N2·C2H4O2, we investigate the influence of F atoms introduced to the aromatic ring on promoting π-π interactions. The cocrystal crystallizes in the triclinic space group P1. Through crystallographic analysis and computational studies, we reveal the molecular arrangement within this cocrystal, demonstrating the presence of hydrogen bonding between the acetic acid molecule and the pyridyl group, along with π-π interactions between the aromatic rings. Our findings highlight the importance of F atoms in promoting π-π interactions without necessitating full halogenation of the aromatic ring.

Combining Orthodontic and Restorative Care with Novel Workflows.

This report describes multidisciplinary care combining orthodontics and restorative dentistry for a patient with Class II occlusion and stained mandibular and maxillary resin composite veneers. The orthodontic treatment improved severe overjet and malocclusion prior to restorative care. Occlusal assessment was provided with a novel digital device (PlaneSystem, Zirkonzahn) that is integrated with digital workflows for the evaluation of the occlusal plane and condylar path inclination. Diagnostic digital impressions and digital wax-up for intraoral mock-ups led to the patient's treatment acceptance. Minimally invasive tooth preparation, final digital impressions, and bonding under dental dam isolation fulfilled the patient's esthetic and functional demands with all-ceramic restorations.

Effect of multi-layer applications of self-etch universal bonding agents on the adhesion of resin composite to enamel.

To evaluate the effect of adhesive coats application on the enamel microtensile bond strength (µTBS) of universal adhesives, morphological etching pattern and their chemical interaction with hydroxyapatite (HA). Two universal adhesives were investigated: Scotchbond Universal (SBU, 3 M) and Prime&Bond Universal (PBU, Dentsply). The adhesives were applied in self-etching mode on bovine enamel (n = 8) in one (1L), two (2L) or three coats (3L) and light-cured as per manufacturers' instructions. As controls adhesives were applied to etched enamel (H3PO4-37% phosphoric acid). Bonded specimens were cut into sticks that were stored in deionized water for 24 h or 6 months prior to µTBS testing. Two-way ANOVA and Tukey's test were used for statistical analysis of bond strength with α = 5%. For morphological SEM analysis, enamel surfaces were treated as aforementioned and immediately rinsed with acetone. The intensity of monomer-calcium salt formation from each treatment was measured via infrared spectroscopy (ATR-FTIR). All treatments presented no significant reduction on µTBS after aging (p > 0.05). However, SBU attained highest µTBS when applied in 3L. PBU showed higher µTBS when applied to H3PO4 etched enamel than 1L or 2L. Etching pattern was enhanced by 3L application, particularly with PBU. Chemical interaction was notably higher for SBU than PBU, with no relevant differences with more layers or prior H3PO4-etching. The application of three adhesive coats of universal adhesives in self-etch mode using may enhance the bonding performance and etching pattern to enamel, surpassing the H3PO4-etched enamel bond for SBU. The chemical interaction with calcium from enamel is not affected by number of coats or prior phosphoric acid etching.

Effect of Phytic Acid Etching and Airborne-Particle Abrasion Treatment on the Resin Bond Strength.

Objective: This study aimed to evaluate the bond strength of a universal adhesive to dentin (µTBS) using different time periods of airborne particle abrasion (APA) and two types of acid etching. Methods: Seventy-two human third molars were divided into 9 groups (n=8) according to dentin pretreatment: APA duration (0, 5, or 10s) and acid etching (no acid - NA, 37% phosphoric acid - PhoA, or 1% phytic acid - PhyA). APA was performed at a 0.5 cm distance and air pressure of 60 psi using 50 µm aluminum oxide particles. Afterwards, two coats of Single Bond Universal adhesive (3M) were applied to the dentin surface. Composite blocks were built using the incremental technique, sectioned into 1×1 mm slices and subjected to microtensile bond strength (µTBS) testing. Fracture patterns and surface topography of each dentinal pretreatment were evaluated using a Scanning electron microscope (SEM). Bond strength data were analyzed using two-way ANOVA and Bonferroni post-hoc tests. Results: The group that received pretreatment with 5s APA and PhoA presented higher µTBS values among all groups, which was statistically different when compared with the PhoA, 10APA+PhoA, and 5APA+PhyA groups. PhyA did not significantly influence the bond strength of the air-abraded groups. Finally, adhesive failure was considered the predominant failure in all groups. Conclusion: Dentin pretreated by airborne particle abrasion using aluminum oxide demonstrated an increase in bond strength when abraded for 5 seconds and conditioned with phosphoric acid in a universal adhesive system.

Mother-infant bonding: The role of postpartum depression, violence, and bonding established with one's own mother during childhood.

Mother-infant bonding is influenced by several risk and protective factors, and the literature has investigated the relationships between these factors independently. This study aimed to verify the interrelationships of some of these factors and how they influence mother-infant bonding in Brazil. In this study, 361 mothers participated, and the outcome variable of mother-infant bonding was assessed using the Postpartum Bonding Questionnaire (PBQ). Multivariate regression analysis was performed using a hierarchical model with three blocks structured according to the influence exerted on mother-infant bonding. The PBQ's factor scores were estimated and used in the subsequent analyses to decrease measurement error. The variable "violence experienced by mothers" was statistically significant for explaining the second block model but not significant for the third block. Network analysis was performed after multiple regression, showing that the violence experienced by mothers does not directly influence mother-infant bonding but rather is mediated by postpartum depression. This explains why violence is not significant in the hierarchical multiple regression when maternal depression is added to the model. This study's strengths lie in its utilization of PBQ factor scores and network analysis, enabling the estimation of conditional relationships among variables. This approach provides deeper insights into factors affecting mother-infant bonding.

Varios factores de riesgo y de protección ejercen influencia sobre la unión afectiva madre­infante; la literatura disponible ha investigado las relaciones entre estos factores de una manera independiente. Este estudio se propuso verificar las interrelaciones de algunos de estos factores y cómo ellos influyen en la unión afectiva madre­infante. Se consultó un total de 361 madres y el variable resultado de afectividad madre­infante se evaluó por medio del Cuestionario de Afectividad de Postparto (PBQ). Se llevaron a cabo análisis de regresión multivariados usando un modelo jerárquico con tres estructuras de bloques de acuerdo con la influencia ejercida sobre la unión afectiva madre­infante. Se estimaron y usaron los puntajes de factores del PBQ en los análisis subsecuentes para disminuir el error en la medida. La variable "violencia experimentada por las madres" fue estadísticamente significativa para explicar el segundo modelo de bloque, pero no significativa para el tercer bloque. Se llevó a cabo un análisis de interrelaciones después de la regresión múltiple, demostrando que la violencia experimentada por las madres no influye directamente la afectividad madre­infante, sino que la misma es mediada por la depresión posterior al parto. Esto explica por qué la violencia no es significativa en la jerárquica regresión múltiple cuando la depresión materna se le agrega al modelo. Entre los puntos fuertes de este estudio se incluye el uso de los puntajes de factores del PBQ y el análisis de interrelaciones, lo cual permitió que se estimaran las relaciones condicionales existente dentro del grupo de variables, aportando una mayor comprensión de algunos factores que interfieren en la unión afectiva madre­infante.

Restablecimiento de guía anterior con restauraciones adhesivas / Reestablishing of anterior guidance with adhesive restorations

La estética ha llegado a formar una parte muy importante en la odontología actual. Sin embargo, no debemos sobreponer las necesidades estéticas sobre las necesidades funcionales. La pérdida de estructura dental asociada a bruxismo puede ser considerada patológica cuando compromete la guía anterior, la cual es la influencia en los movimientos mandibulares que proveen las superficies contactantes de los dientes maxilares anteriores con los mandibulares anteriores y evita contactos excéntricos dañinos en los dientes posteriores. El objetivo de este reporte de caso es presentar una alternativa conservadora para restablecer tanto la estética como la funcionalidad de una paciente de 34 años de edad que acudió a la Clínica de Prostodoncia de la Universidad Autónoma de Guadalajara en busca de rehabilitación estética de dientes anteriores. Una vez realizada su evaluación inicial se llegó al diagnóstico de pérdida de guía anterior por desgaste patológico asociado a bruxismo. El tratamiento incluyó tratamientos de conductos, remoción de caries y restauraciones mal ajustadas, coronas y carillas para restablecer la guía anterior. Se cumplieron con las expectativas estéticas que tenía la paciente al igual que con las necesidades funcionales que fueron objetivo desde el inicio, logrando un restablecimiento de la guía anterior de manera conservadora (AU)

Esthetics has become a very important part of dentistry today. However, we should not superimpose esthetic needs over functional needs. The loss of tooth structure associated with bruxism can be considered pathologic when it compromises the anterior guidance, which is the influence on mandibular movements that provides the contacting surfaces of the maxillary anterior teeth with the mandibular anterior teeth and avoids damaging eccentric contacts in the posterior teeth. The aim of this case report is to present a conservative way to restore both esthetics and function in a 34-year-old patient who came to the Prosthodontics Clinic of the Universidad Autónoma de Guadalajara in search of an esthetic appearance of her anterior teeth. After her initial evaluation, a diagnosis of anterior guide loss due to pathological wear associated with bruxism was made. Treatment included root canal treatment, removal of caries, and ill-fitting restorations, crowns, and veneers to reestablish the anterior guidance. The aesthetic expectations of the patient have met as well as the functional needs that were aimed from the beginning, achieving a conservative reestablishment of the anterior guidance system (AU)

Expanding chalcogen bonds in thiophenes to interactions with halogens.

Compounds containing the thiophene moiety find several applications in physics and chemistry, such as electrical conduction, which depends on specific conformations to properly exhibiting the desired properties. In turn, chalcogen bonding has found to modulate the conformation of some N-thiophen-2-ylfomamides. Since halogens participate in a kin interaction (halogen bonding) and are abundant in agrochemicals, pharmaceuticals, and materials, we have quantum-chemically explored the interaction between organic halogen and thiophene as a conformational modulator in some model compounds. Although such interaction indeed appears, as demonstrated by atoms in molecules and natural bond orbital analysis, it is inefficient to control the conformational equilibrium. An energy decomposition analysis scheme demonstrated that halomethane and thiophene tend to move away from one another due to a core component (Pauli repulsion and exchange), which is mainly due to a deformation term. Therefore, chalcogen bonds with halogens appear weaker than with other chalcogens.

Clinical performance of posterior restorations using a universal adhesive over moist and dry dentin: A 36-month double-blind split-mouth randomized clinical trial.

OBJECTIVES: To evaluate the influence of dentin moisture on the clinical behavior of a universal adhesive on posterior teeth after 36 months of follow-up. METHODS: Forty-five patients participated in this study. Following a split-mouth design, three operators placed 90 Class I/Class II restorations over moist dentin (MD) or dry (DD) (n = 45) with resin composite (Filtek Bulk Fill) and a universal adhesive used in the etch-and-rinse mode (Single Bond Universal). Each restoration was evaluated according to the FDI and USPHS criteria (postoperative sensitivity, fracture and retention, marginal staining, marginal adaptation, and recurrence of caries) at baseline and after 6-, 12-, and 36 months. For statistical analysis, Kruskal Wallis analysis of variance rank (α = 0.05) and Kaplan-Meier survival analysis were used. RESULTS: No significant difference between groups was observed in each FDI criterion after 36 months of clinical evaluation (p > 0.05). The retention rates (confidence interval 95 %) were 97.37 % (86.5 - 99.5) for both MD and DD without significant difference between them (p > 0.05). Eight restorations (MD = 4; DD = 4) showed minimal marginal staining defects (p > 0.05). Two restorations were lost (MD = 1; DD = 1). Fifteen restorations (MD = 8; DD = 7) presented minor marginal discrepancies according to the FDI criteria (p > 0.05). CONCLUSION: The clinical performance of the universal adhesive when applied in etch-and-rinse mode was not influenced by dentin moisture in posterior bulk-fill composite restorations. CLINICAL SIGNIFICANCE: The level of dentin moisture appears not to influence the clinical efficacy of a universal adhesive when applied using the etch-and-rinse technique in posterior composite resin restorations.

Longer light-curing time decreases the effect of ageing on composite resin hardness used in root reinforcement.

This study evaluated the hardness of a composite resin used for root reinforcement, considering the light-curing time, root canal region and ageing due to long-term storage. Twenty incisor roots were reinforced using composite resin, varying the photopolymerisation time (40 or 120 s). Following fibre post cementation, the roots were transversely sectioned into coronal, middle and apical regions. Composite hardness was measured initially and after 18 months of water storage. Data underwent repeated measures analysis of variance and Tukey's post hoc tests. The factors 'light-curing time', 'root region' and 'ageing' affected the hardness. Significant interactions were observed between 'light-curing time × root region' and 'ageing × light-curing time'. Regardless of time, resin hardness in the apical region was lower. After ageing, hardness in the coronal and middle regions decreased when the light-curing time was 40 s, while no significant effect on hardness was noted with a light-curing time of 120 s.

Decoding the mechanism governing the structural stability of wheat germ agglutinin and its isolated domains: A combined calorimetric, NMR, and MD simulation study.

Wheat germ agglutinin (WGA) demonstrates potential as an oral delivery agent owing to its selective binding to carbohydrates and its capacity to traverse biological membranes. In this study, we employed differential scanning calorimetry and molecular dynamics simulations to comprehensively characterize the thermal unfolding process of both the complete lectin and its four isolated domains. Furthermore, we present the nuclear magnetic resonance structures of three domains that were previously lacking experimental structures in their isolated forms. Our results provide a collective understanding of the energetic and structural factors governing the intricate unfolding mechanism of the complete agglutinin, shedding light on the specific role played by each domain in this process. The analysis revealed negligible interdomain cooperativity, highlighting instead significant coupling between dimer dissociation and the unfolding of the more labile domains. By comparing the dominant interactions, we rationalized the stability differences among the domains. Understanding the structural stability of WGA opens avenues for enhanced drug delivery strategies, underscoring its potential as a promising carrier throughout the gastrointestinal environment.

Adhesion and sealing of different universal adhesive systems associated with bulk-fill resins after using endodontic irrigation solutions: An in vitro study.

This study aimed to evaluate the interface of universal adhesive (UA) with bulk-fill resin (BF) and dentin, after endodontic irrigation. The pulp chamber of 96 molars was irrigated with chlorhexidine 2% (CHX) or sodium hypochlorite 5.25% (NaOCl) and restored according to three restorative protocols. Microtensile bond strength (µTBS) and nanoleakage tests were performed after 24 h of thermocycling. Kruskal Wallis, Mann-Whitney and Wilcoxon were performed (p < 0.05). Comparing restorative systems, a difference was found only when irrigated with CHX after 24 h. CHX provided higher µTBS than NaOCl after 24 h for two restorative protocols; after thermocycling, NaOCl provided the greatest µTBS than CHX for one group. Decreased µTBS was observed for all restorative systems when CHX was used after thermocycling. NaOCl demonstrated the highest nanoleakage. The composition of UA influenced the immediate adhesion and sealing to BF when CHX was used; ageing has a deteriorating effect on adhesion and sealing for all restorative systems.

Pomegranate extract on eroded dentin: antioxidant action, bond strength and morphology of the adhesive interface after aging.

Objectives: This study aimed to evaluate the effect of pomegranate solution (Punica granatum) on eroded dentin through antioxidant action, shear bond strength (SBS) and interface morphology. Materials and Methods: The 10% pomegranate peel extract was prepared by the lyophilization method. Punicalagin polyphenol was confirmed by high-performance liquid chromatography. Antioxidant activity was evaluated by capturing the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. For the SBS, 48 dentin fragments were divided into sound or eroded, and subdivided according to the pretreatment (n = 12): water or P. granatum. The surfaces were restored with self-etch adhesive and a bulk-fill resin (Ecosite; DMG). The SBS was done immediately (24 hours) and after thermal cycling + water storage (12 months). For scanning electron microscopy, 48 dentin fragments (24 sound and 24 eroded) received the same treatments as for SBS (n = 6), and they were analyzed after 24 hours and 12 months. Results: The P. granatum had antioxidant action similar (p = 0.246) to the phenolic standard antioxidants. After 24 hours, eroded dentin had lower SBS than sound dentin (p < 0.001), regardless of the pretreatment. After 12 months, P. granatum maintained the SBS of sound dentin (13.46 ± 3.42 MPa) and eroded dentin (10.96 ± 1.90 MPa) statistically similar. The lowest values were found on eroded dentin treated with water (5.75 ± 1.65 MPa) (p < 0.001). P. granatum on eroded dentin caused peritubular demineralization and hybrid layer with resin tags. Conclusions: The pomegranate extract had antioxidant action and preserved the adhesive interface of the eroded dentin.

Influence of silver fluoride plus potassium iodine on adhesive properties of primary carious dentin-resin interface: An in vitro study.

This paper evaluated the influence of different protocols of silver fluoride (SF) pretreatment of artificial carious lesions on the adhesive interface of composite resin restorations and remineralization of deciduous dentin compared to silver diamine fluoride (SDF). Sixty-four deciduous molar teeth were randomly divided into 8 groups (n = 8) according to the restoration time (immediately - IM; 30 days after SDF/SF treatment - 30 D) and treatment before restoration (SDF 38 %; SDF 38 % + potassium iodide - KI; SF 38 %; SF 38 % +KI). After SDF/SF application, teeth in the IM group were restored with self-etch universal adhesive system/composite resin. Samples in the 30D groups were stored in artificial saliva (37 °C) for 30 days before receiving the same restoring protocol. Beams were obtained from all groups and subjected to bond strength tests (µTBS), ultrastructural qualitative analysis (FEG) and mineral analysis (SEM/EDX; Micro-Raman spectroscopy). The µTBS data were subjected to three-factor ANOVA and multiple comparisons (Holm-Sidak method). Bond strength values (MPa) for IM groups were 16.9 ± 2.7 (SDF); 17.6 ± 3.5 (SDF + KI); 16.8 ± 5.5 (SF); 18.4 ± 4.1 (SF + KI); and 14.9 ± 4.2 (SDF); 16.0 ± 5.4 (SDF + KI); 14.1 ± 3.6(SF); 16.4 ± 5.4 (SF + KI) for 30D groups. Bond strength wasn't influenced by the moment of restoration (IM or 30D); the use of KI didn't alter adhesion characteristics; SDF/SF solutions resulted in similar adhesive strength; calcium and phosphate expressions were identified at the interfaces on IM and 30D moments. However, 30D presented qualitative increase in these ions, compatible with remineralization. It was concluded that the adhesion of composite resin restorations in artificial caries lesions of deciduous teeth treated with SDF (38 %) and SF (38 %) had similar effects in vitro; the use of KI or the moment when restorations were accomplished did not influence the adhesion and all tested protocols promoted remineralization of carious dentin.

Exploring the role of flavonoids in caries-affected dentin adhesion: A comprehensive scoping review.

OBJECTIVES: The aim of this scoping review was to evaluate the available scientific evidence regarding the use of flavonoids in the treatment of caries-affected dentin focusing on bonding to dentin. METHODS: A comprehensive literature search was performed in five databases from March 2022 and updated in April 2023: PubMed, EMBASE, Scopus, Web of Science, and Scielo. Additionally, the references of included studies were manually searched. Gray literature was excluded from the review. STUDY SELECTION: Inclusion criteria included in vitro, in situ, and in vivo studies (animal or human) published in English. Abstracts, reviews, case reports, book chapters, doctoral dissertations, guidelines, and studies using pure plant extracts were excluded. Data collected from the selected studies were summarized and subjected to narrative and descriptive analysis. Out of the 91 studies identified, only 16 studies met the inclusion criteria. RESULTS: The review analyzed eight different flavonoids (hesperidin, galardin, proanthocyanidin, genipin, quercetin, naringin, epigallocatechin-3-gallate, and other catechins subtypes) used as pretreatment or loaded into adhesive systems, primers, and phosphoric acid. The use of flavonoids improved the mechanical properties of the materials and modified the biological properties of the dentin, reducing collagen loss by the inhibition of proteolytic activity of matrix metalloproteinases (MMPs). CONCLUSIONS: Based on the findings of this scoping review, it can be concluded that the use of flavonoids as pretreatment or incorporation into dental materials preserves collagen in the hybrid layer, inhibiting the MMPs activities, modifying the collagen fibrils of the dentin matrix and improving the mechanical properties of the dental adhesive systems. Therefore, it represents a promising approach for promoting dentin biomodification. This can result in more stable bonding of adhesive restorations to caries-affected dentin.

Influence of airborne particle abrasion on dentin bonding effectiveness of a 2-step universal adhesive.

OBJECTIVE: To determine the effect of airborne particle abrasion (APA) on micro-tensile bond strength (µTBS) to dentin using different air-abrasion/polishing powders. METHODS: The bonding effectiveness of G2 Bond Universal (G2B), used in etch-and-rinse (E&R) and self-etch mode (SE), was tested on bur-cut dentin and dentin air abraded/polished using six different powders (aluminum oxide 29 µm (AO29) and 53 µm (AO53), aluminum trihydroxide (AT), sodium bicarbonate (SB), sodium bicarbonate soft (SBsoft) and bioactive glass (BG); Velopex). Adhesive-composite resin specimens were immersed in distilled water at 37 °C for one week and cut into microspecimens. Half of the specimens were subjected to 50,000 thermocycles (aged). Immediate and aged µTBS to dentin were measured. Statistical analysis was performed using linear mixed-effects (LME) modeling (p < 0.05). RESULTS: Comparing the aged bond strengths to air-abraded/polished dentin with bur-cut dentin, pretreatment with SB and SBsoft in combination with G2B used in E&R mode, and BG air polishing in combination with both application modes (E&R, SE), resulted in a significantly higher bond strength. Dentin bond strength was only significantly lower when air abraded with AO29 and using G2B in SE mode. Aging did not significantly influence bond strength for both application modes (E&R, SE), except for AO29 and AT-treated dentin, where bond strengths decrea sed significantly using G2B in SE mode. In general, G2B reached significantly higher bond strengths on air-abraded/polished dentin in E&R mode than in SE mode. CONCLUSION: Air-abrasion/polishing did not impair dentin bond strength using G2B, except when dentin was air abraded with AO29 and using G2B in SE mode. Air polishing positively influenced the bond strength to dentin in specific groups. CLINICAL SIGNIFICANCE: APA is safe concerning bonding to dentin. The E&R application mode is preferred using G2B as adhesive on air-abraded/polished dentin. Air polishing with BG positively influenced dentin bond strength for both application methods.

Pnictogen bond-driven control of the molecular interaction between organophosphorus and acetylcholinesterase enzyme.

This study addresses a comprehensive assessment of the interaction between chemical warfare agents (CWA) and acetylcholinesterase (AChE) systems, focus on the intriguing pnictogen-bond interaction (PnB). Utilizing the crystallographic data from the Protein Data Bank pertaining to the AChE-CWA complex involving Sarin (GB), Cyclosarin (GF), 2-[fluoro(methyl)phosphoryl]oxy-1,1-dimethylcyclopentane (GP) and venomous agent X (VX) agents, the CWA is systematically displaced by increments of 0.1 Å along the PO bond axis, extending its distance by 4 Å from the original position. The AIM analysis was carried out and consistently revealed the presence of a significant interaction along the PO bond. Investigating the intrinsic nature of the PnB, the NBO and the EDA analysis unearthed the contribution of orbital factors to the overall energy of the system. Strikingly, this observation challenges the conventional σ-hole explanation commonly associated with such interactions. This finding adds a layer of complexity to understanding of PnB, encouraging further exploration into the underlying mechanisms governing these intriguing chemical phenomena.