Microhardness, diametral tensile strength and color stability of heated resin composites used for luting ceramic veneers.

Purpose: To evaluate color change in ceramic veneers luted to enamel with light-cured, dual-cured resin luting agents, or heated resin composites, as well as to evaluate microhardness and diametral tensile strength of these luting agents.

Methods: For color analysis, 0.5 mm-thick leucite-reinforced glass ceramic veneers (IPS Empress CAD) were cemented onto 40 bovine dental blocks (n= 10) using RelyX Ultimate (RU) or RelyX Veneer (RV) resin-based luting agents, or Gradia Direct (GD) and Palfique Lx5 (P) heated resin composites.

Anatomical Measurement as a Reference for Functional Endoscopic Sinus Surgery Based on CT Scans and Dissections.

Diseases of the paranasal sinuses, nasal cavities, and those related to the skull base can be treated with nasal endoscopic surgery. Anatomical references are essential to safely perform these surgeries.  To measure and compare the distance from the posterior wall of the maxillary sinus to the anterior skull base in cadavers and on computed tomography (CT) scans to determine a measurement as an anatomical reference in imaging exams for sinus and anterior skull base surgery.

Effect of different design and surface treatment on the load-to-failure of ceramic repaired with composite.

Unlabelled: Glass ceramics are widely used to manufacture esthetic veneers, inlays, onlays, and crowns. Although the clinical survival rates ofglass-ceramic restorations arefavorable,fractures or chips are common. Certain cases can be repaired with direct composite.

Impact of COVID-19 pandemic among patients with lung and head and neck cancer assisted in a public cancer center in Brazil.

Background: There is no updated national data regarding the real impact of the COVID-19 pandemic on delaying diagnosis and treatment among patients with lung, and head, and neck cancers in Brazil. This study aimed to analyze the COVID-19 pandemic impact on cancer diagnosis and clinical outcomes among lung, head, and neck cancer patients assisted in a tertiary cancer center in Southeastern Brazil, as well as to analyze these patients' pretreatment clinical features.

Methods: Retrospective cohort of patients with lung or head and neck cancer assisted in a tertiary cancer center in southeastern Brazil between January/2019 and December/2021.

Effect of chemical or mechanical finishing/polishing and immersion in staining solutions on the roughness, microhardness, and color stability of CAD-CAM monolithic ceramics.

Unlabelled: During the manufacture of ceramic restorations there is an important step of finishing and polishing and the effects of different types of these procedures on the surface characteristics of ceramics are not known for sure.

Aim: To evaluate the effects of various surface treatments and immersion in coloring substances on the roughness, microhardness, and color stability of CAD-CAM monolithic ceramics.

Materials And Method: The ceramics used were lithium disilicate reinforced with zirconium dioxide (Suprinity), lithium disilicate (E.

Long-term bond strength of ormocer-based resin composites using a universal adhesive used in different adhesive strategies.

Purpose: To evaluate over time the bond strength to dentin of different resin composites (RBCs) associated with the universal adhesive system applied with self-etching or total-etching strategies.

Methods: 60 human third molars were obtained, randomly divided into experimental groups (n= 10) according to RBCs: methacrylate-based nanofilled (Z350 XT); low-viscosity Ormocer-based bulk-fill (Admira Fusion X-base Universal); or high-viscosity Ormocer-based bulk-fill composite (Admira Fusion X-tra). The adhesion procedure was performed using a universal adhesive (Futurabond U) applied in self-etching or total-etching mode.

Varnish with S-PRG filler reduces dentin permeability after erosive/abrasive challenge.

Purpose: To evaluate the effect of different varnishes on dentin permeability to erosive/abrasive challenges.

Methods: 60 superficial dentin discs were randomly allocated to six groups (n=10): Duraphat, PRG Barrier Coat, Clinpro XT, Profluorid, Fluor Protector S and untreated (control). Permeability tests were carried out: after acid conditioning, after treatment, and after abrasive/erosive challenges.

Fracture load and failure mode of semi-direct resin composite occlusal veneers: Influence of design and mechanical cycling.

Aims: To evaluate the influence of the type of preparation and mechanical cycling on the fracture load and failure mode of semi-direct posterior resin composite restorations.

Methods: In total, 70 healthy third molars were used; 10 belonging to the control group (C - unprepared teeth) and 60 teeth prepared and restored with nanoparticle resin composite, divided into 3 groups (n = 20): O - exclusively occlusal preparation (Table Top); OV - occlusal preparation with buccal extension (Veneerlay); OVP - Occlusal preparation with chamfer on the proximal and buccal-lingual/palatal surfaces (Overlay). The preparations were performed with diamond burs with a thickness of 1 mm.

Ozone gas therapy for tooth bleaching preserves enamel microhardness, roughness and surface micromor.

Unlabelled: After ozone therapy for bleaching, it is important to evaluate enamel surface properties, to ensure that bleaching provides adequate conditions for sound dental substrate. Aim: The aim of this in vitro study was to evaluate the effects of a bleaching treatment with 10% carbamide peroxide (CP), with or without ozone (O), on the microhardness, roughness and micromorphology of the enamel surface.

Materials And Method: Bovine enamel blocks were planed and distributed among the following three bleaching treatment groups (n=10): CP - 1 hour per day/14 days (Opalescence PF 10%/ Ultradent); O - 1 hour per day every 3 days/3 sessions (Medplus V Philozon, 60 mcg/mL and oxygen flow rate of 1 L/min); and OCP - CP with O, 1 hour per day every 3 days/3 sessions.

Effect of endodontic sealers on push-out bond strength of CAD-CAM or prefabricated fiber glass posts.

This study aimed to evaluate the effect of endodontic sealer (ES) on bond strength (BS) of prefabricated or milled-CAD-CAM (computer-aided design and computer-aided manufacturing) glass-fiber-posts (GFP). Canals of 90 single-rooted teeth were prepared for filling by the single-cone technique with gutta-percha and one of the following ES: AH Plus (epoxy resin), Endofill (zinc-oxide and eugenol), and Bio-C Sealer (calcium-silicate). After post-space preparation, tooth-specimens were equally divided in half according to type of GFP to be used.

Bonding strategy of a universal adhesive system containing chitosan: influence on dentin permeability, and effect on adhesive layer micromorphology.

Aim: This study evaluated the influence of chitosan added to a universal adhesive system used in totaletch (TE) or self-etch (SE) mode on dentin permeability, and on the micromorphology of the adhesive layer.

Materials And Method: Dentin discs were obtained from human third molars and randomly distributed according to bonding strategy (TE or SE), and to whether or not 1% chitosan (C) was added to a universal adhesive system (Single Bond Universal/3M ESPE), to create the following groups (n=10): TE, TEC, SE, and SEC. Dentin permeability was measured at baseline and after application of dentin treatments.

Physicochemical evaluation of hydrogen peroxide bleaching gels containing titanium dioxide catalytic agent, and their influence on dental color change associated with violet LED.

Background: The purpose of this study was: 1) to analyze the physical-chemical properties of hydrogen peroxide (HP) agents at 7.5% (HP7) and 35% (HP35), and the association with or without TiO nanotubes; 2) to evaluate dental bleaching effectiveness by using HP7 and HP35 together with or without TiO nanotubes, and applied with or without violet LED (VL).

Methodology: 80 bovine incisors were treated according to groups (n = 10): HP35; HP35 + VL; HP35T (HP35 + TiO); HP35T + VL; HP7; HP7 + VL; HP7T (HP7 + TiO); HP7T + VL.

Neuraminidase is a host-directed approach to regulate neutrophil responses in sepsis and COVID-19.

Background And Purpose: Neutrophil overstimulation plays a crucial role in tissue damage during severe infections. Because pathogen-derived neuraminidase (NEU) stimulates neutrophils, we investigated whether host NEU can be targeted to regulate the neutrophil dysregulation observed in severe infections.

Experimental Approach: The effects of NEU inhibitors on lipopolysaccharide (LPS)-stimulated neutrophils from healthy donors or COVID-19 patients were determined by evaluating the shedding of surface sialic acids, cell activation, and reactive oxygen species (ROS) production.

Titanium dioxide nanotubes in a hydrogen peroxide-based bleaching agent: physicochemical properties and effectiveness of dental bleaching under the influence of a poliwave led light activation.

Objectives: The effects of different concentrations of titanium dioxide (TiO) into 40% hydrogen peroxide (HP) were evaluated as regards the effectiveness of dental color change either associated with activation by polywave LED light or not.

Materials And Methods: TiO (0, 1, 5, or 10%) was incorporated into HP to be applied during in-office bleaching (3 sessions/40 min each). Polywave LED light (Valo Corded/Ultradent) was applied or not in activation cycles of 15 s (total time of 2 min).

Seasonal variation in the chemical composition and larvicidal activity against Aedes aegypti L. of essential oils from Brazilian Amazon.

Arthropod-borne viral diseases are important public health threats in tropical countries. In the Americas, diseases such as Dengue, Zika, Chikungunya, Mayaro, and Yellow fever, which are mainly transmitted by Aedes aegypti L. are responsible for high rates of morbidity and mortality in the populations.

Bulk-fill restorative composites under simulated carious and erosive conditions.

Acidic conditions can cause hydrolysis and accelerate degradation of resin composites (RCs). Since there are limited and controversial data on the effect of acids on bulk-fill RCs, this study assessed the surface roughness (SR) and flexural strength (FS) of these RCs under simulated carious and erosion conditions. Bars of Filtek Bulk Fill (FBF, 3M/ESPE), X-tra fil (XTF, Voco), Tetric N-Ceram Bulk Fill (TBF, Ivoclar/Vivadent), and Aura Bulk Fill (ABF, SDI) and a conventional RC [Filtek Z350XT (FZ, 3M/ESPE)] were allocated (n=15) to undergo caries or erosion conditions.

Implant-Abutment Misfit after Cyclic Loading: An In Vitro Experimental Study.

This study aimed to evaluate the influence of thermomechanical cycling (TMC) and type of abutment on the misfit and compressive strength of the implant−abutment interface. Forty 3.75-mm external hexagon implants with 25° angled abutments were divided into four groups (N = 10).

Effects of ionizing radiation and different resin composites on shear strength of ceramic brackets: an in vitro study.

Introduction: Head and neck cancer is considered one of the most common types, and its treatment includes radiotherapy, which can trigger side effects and undesirable sequelae in the oral cavity and dental tissues.

Objective: This study aimed to make an in vitro evaluation of the shear strength and failure mode of ceramic orthodontic brackets bonded with two different composites in enamel submitted to ionizing radiation.

Methods: After the study was approved by the Research Ethics Committee, 60 healthy human premolars were selected and divided into two groups, based on the absence or presence of ionizing irradiation of the enamel.

Effect of different polishing systems and staining solution on surface roughness and color stability of bulk fill resin composites.

Purpose: To evaluate the effect of polishing systems (discs or rubbers) on surface roughness (Ra) and color change (ΔE) of two bulk fill and one conventional resin composite after immersion in a dye solution.

Methods: 180 samples (10 mm x 2 mm) were separated into three groups: (1) Resin composite: Filtek One Bulk Fill (FO), Tetric N-Ceram Bulk Fill (TNC), Filtek Z350 XT (FXT) (n= 60); (2) polishing system: unpolished (control); aluminum oxide discs (Sof-Lex, AOD); cup-shaped abrasive rubber polishers (Astropol, CSA) (n= 20), and (3) immersion solutions: coffee or distilled water (n= 10). Immersion was under 5 mL of each solution for 3 hours daily, for 30 days.

Dimethyl Sulfoxide Dentin Pretreatments Do Not Improve Bonding of a Universal Adhesive in Etch-and-Rinse or Self-etch Modes.

Purpose: To evaluate the influence of dimethyl sulfoxide (DMSO) solutions used as dentin pretreatments on microtensile bond strength (µTBS), as well as the dentin/restoration interface micromorphology of a universal adhesive in etch-and-rinse or self-etch mode.

Materials And Methods: Eighty blocks of dentin were submitted to acid conditioning with 35% phosphoric acid (etch-and-rinse), or not (self-etch), and distributed among the treatments (n = 10): CON: Scotchbond Universal/3M Oral Care; DMSO: pretreatment with DMSO; DMSO/water: pretreatment with DMSO in water (1:1); DMSO/ethanol: pretreatment with DMSO in ethanol (1:1). Microtensile bond strength and failure tests were performed after 24-h and 6-month storage.

The use of desensitizing agents during in-office bleaching might not decrease tooth bleaching sensitivity: a randomized clinical trial.

Background: Due to controversial results in relation to the influence of desensitizing agents on sensitivity during bleaching, the present study evaluated the degree of tooth bleaching sensitivity, color change, and patient acceptability of desensitizing agents containing potassium nitrate/sodium fluoride (PNF) or nanostructured calcium phosphate (N) associated with in-office bleaching with 35% hydrogen peroxide (HP).

Materials And Methods: Seventy-five patients were randomly distributed into three groups (n = 25): 1) Group W - in-office bleaching (Whiteness HP Maxx - three sessions of 45 min); 2) Group WD - associated with PNF desensitizing gel (Desensibilize KF 2%) applied for 10 min before each session; 3) Group WDN - associated with N desensitizing paste (Desensibilize Nano P) applied after bleaching for 5 min. The degree of sensitivity and patient acceptability of the desensitizing treatments were evaluated using a visual analog scale.

Effect of whitening dentifrices on color, surface roughness and microhardness of dental enamel in vitro.

Purpose: To evaluate the color, surface roughness and microhardness of human dental enamel subjected to brushing with whitening dentifrices.

Methods: The enamel samples (4 x 4 x 2 mm) were darkened using 0.2% chlorhexidine and black tea, and were randomly divided into seven groups (n= 15) for brushing cycles with only water; control; conventional dentifrice (Colgate Maximum Anticaries Protection); dentifrice containing 2% hydrogen peroxide (Colgate Luminous White Advanced); dentifrice containing sodium tripolyphosphate (Sensodyne True White); dentifrice containing activated charcoal (Black is White); and dentifrice containing blue covarine (Close Up White Now).

Assessment of frictional resistance and surface roughness in orthodontic wires coated with two different nanoparticles.

Several mechanical and biological factors may change the orthodontic wire frictional resistance (FR). Titanium dioxide (TiO ) and silica dioxide (SiO ) nanoparticle (NP) coatings may be used to improve the characteristics of materials, reducing FR between archwire and bracket. This in vitro study aimed to evaluate the FR of orthodontic wires with and without coating in both dry and wet environments and measure the surface roughness (SR).

Immediate and long-term microshear bond strength of resin-based cements to core build-up materials.

Background: To evaluate the microshear bond strength (μ-SBS) between resin-based cements and core build-up materials after water storage.

Material And Methods: Cylinders (1x1 mm) of conventional dual-cure resin cement (RelyX ARC, 3M ESPE), universal dual-cure resin cement (RelyX Ultimate, 3M ESPE) or self-adhesive resin cement (RelyX U200, 3M ESPE) were adhered to disks (6x2 mm) made with commercial core build-up materials (Bis-Core, Bisco or LuxaCore Z, DMG) or conventional nanocomposite resin (Filtek Z350 XT, 3M ESPE). The specimens (n=10) were submitted to μ-SBS test using a universal testing machine and fracture pattern analysis at 48 hours or after 9 months of water storage.

Low- and high-viscosity bulk-fill resin composites: a comparison of microhardness, microtensile bond strength, and fracture strength in restored molars.

The aim of this study was to compare low- and high-viscosity bulk-fill composites for Knoop microhardness (KHN), microtensile bond strength (MTBS) to dentin in occlusal cavities, and fracture strength (FS) in molars with mesialocclusal- distal restoration. Disk-shaped samples with different thicknesses (2 or 4 mm) of low-viscosity (SDR Flow, Dentsply) and high-viscosity bulk-fill composites (Filtek BulkFill, 3M ESPE; and Tetric-N Ceram Bulk Fill, Ivoclar Vivadent) were prepared for top and bottom KHN analysis (n=10). MTBS to dentin and fracture pattern was evaluated in human molars with occlusal cavities restored with (n=10): conventional nanocomposite (Z350XT, 3M ESPE), low-viscosity (Filtek Bulk-fill Flow, 3M ESPE) or high-viscosity bulk-fill composites (Filtek BulkFill).