MARPE expander activation load with different configurations of extender arms heights: in-vitro evaluation.

Objective: Evaluate the load mini-implants exert on the artificial bone when expanding the MARPE EX in three different extension arm configurations.

Methods: A device simulating the human palate was fabricated and attached to a universal testing machine, for conducting tests with different MARPE expanders (n=5): non-adjustable/control (MARPE SL, Peclab) or with low, intermediate, and high extender arms (MARPE EX, Peclab). The expanders were manually activated until failure of the device occurred, and maximum load values were recorded.

Influence of viscosity and fiber reinforcement of resin composite on fracture strength and failure mode of restored molars.

Objective: To evaluate the fracture behavior of human molars with extensive MOD restorations using short-fiber-reinforced resin composite of varying viscosities.

Materials And Methods: Human molars were randomly divided into seven groups (n = 12): intact teeth (control); restoration using conventional high-viscosity resin composite without (Filtek Z350XT, 3M) or with fibers (everX Posterior, GC); conventional low-viscosity resin composite without (Filtek Supreme Flowable, 3M) or with fibers (everX Flow Dentin Shade, GC); bulk-fill low-viscosity resin composite (Filtek Bulk Fill Flow, 3M) or with fibers (everX Flow Bulk Shade, GC). Restorations were performed on extensive MOD preparations, following the manufacturers' recommendations for each material.

Effect of a brush tip on in-office bleaching gels in an attachable syringe: Hydrogen peroxide penetration, bleaching efficacy and amount of gel expended.

Objective: Evaluate the penetration of hydrogen peroxide (HP) into the pulp chamber, bleaching efficacy (BE) and amount of gel expended during in-office bleaching using an applicator brush tip and conventional tip from different commercial brands.

Materials And Methods: 104 human premolars were randomly distributed into thirteen groups (n = 8) according to the commercial brand: DSP White Clinic 35 % Calcium (DW), Nano White 35 % (NW), Total Blanc One-Step 35 % (TS), Whiteness HP Blue 35 % (WB), Potenza Bianco Pro SS 38 % (PB), Opalescence XTra Boost 40 % (OB), no bleaching (negative control), and application method: applicator brush tip and conventional tip for all groups. Initial HP concentration (%) was determined via titration and pH was measured with digital pH meter.

Influence of etchant type on the shear bond strength of orthodontic brackets to enamel.

The aim of this study was to evaluate the influence of the type of etchant on the shear bond strength (SBS) of metallic brackets to enamel and the Adhesive Remnant Index (ARI) after debonding. A total of 30 mandibular and maxillary premolars were randomly distributed into groups (n = 10) treated with 1 of 3 enamel surface-conditioning agents: 35% phosphoric acid (PA), 35% glycolic acid (GA), or 35% ferulic acid (FA). The designated acid was applied to the buccal enamel surface of the tooth for 20 seconds, and the tooth was then rinsed with distilled water for 20 seconds and air dried for 5 seconds.

Effectiveness of changing the color of darker teeth is potentiated by association with violet LED light.

Background: The effectiveness of in-office bleaching protocols performed with violet LED light either combined with a bleaching agent containing 37% carbamide peroxide, or not, was determined by comparing teeth with different degrees of darkening.

Methodology: Eighty bovine incisors were separated into groups of "light" teeth (luminosity greater than or equal to B3) and "dark" teeth (less than or equal to A3.5) to receive the protocols: HP - 35% hydrogen peroxide (Whiteness HP), CP - 37% carbamide peroxide (Whiteness SuperEndo), LED - violet LED light (Bright Max Whitening), CPLED - CP associated with the LED.

Hybrid light applied with 37% carbamide peroxide bleaching agent with or without titanium dioxide potentializes color change effectiveness.

Background: The effectiveness of dental color change was assessed by incorporating titanium dioxide (TiO) into 37% carbamide peroxide bleaching agent associated with hybrid light.

Methodology: Fifty bovine incisors were selected to receive the bleaching treatment, and separated into five groups (n = 10): 35% hydrogen peroxide (HP) (Whiteness HP, FGM/HP); 37% carbamide peroxide (CP) (Whiteness SuperEndo, FGM/CP); CP + hybrid light (HL) (CP HL); CP + 1% TiO (CP TiO); CP TiO + hybrid light (CP TiO HL). The bleaching gels were applied to the dental surface for 30 min.

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.

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.

Continuous vs fractionated violet LED light protocols for dental bleaching: Evaluations of color change and temperature of the dental pulp and buccal surface.

Background: Dental color change and the temperature of the pulp chamber and of the buccal surface were evaluated during bleaching with 37% carbamide peroxide (CP) with continuous vs fractionated violet LED light protocols.

Methodology: Bovine incisors received in-office bleaching for 30 min using different light protocols (Bright Max Whitening, MMOptics). Teeth were separated into groups (n = 10): HP) 35% hydrogen peroxide (Whiteness HP, FGM)/no light; CP) 37% carbamide peroxide (Whiteness SuperEndo, FGM)/no light; CP10) CP+10 min of continuous light; CP20) CP+20 min of continuous light; CP30) CP+30 min of continuous light; CPF) CP+20 cycles of 60 s light / 30 s no light (fractionated).

Wet-bonding technique with ethanol may reduce protease activity in dentin-resin interface following application of universal adhesive system.

Background: Greater degradation of the hybrid layer is expected when a universal adhesive system is used, especially in the conventional application strategy. Therefore, it would important to evaluate the effect of the ethanol (ETH) and a potential matrix protease inhibitor (caffeic acid phenethyl ester/ CAPE) to maximize the ability to achieve stable dentin bond strength. The aim of this study was to evaluated the effect of ETH on a wet-bonding technique, and dentin pretreatments with different concentrations of CAPE in ethanolic solution, followed by application of a universal adhesive system (Single Bond Universal) to inhibit proteolytic activity.

Stress distribution on implant- supported zirconia crown of maxillary first molar: effect of oblique load on natural and antagonist tooth.

This study evaluated the stress distribution on an implant-supported zirconia crown of a mandibular first molar subjected to oblique loading by occlusal contact with the natural maxillary first molar by using the 3D finite element method. Two virtual models were made to simulate the following situations: (1) occlusion between maxillary and mandibular natural first molars; (2) occlusion between zirconia implant-supported ceramic crown on a mandibular first molar and maxillary natural first molar. The models were designed virtually in a modeling program or CAD (Computer Aided Design) (Rhinoceros).

Effects of in vitro erosion on surface texture, microhardness, and color stability of resin composite with S-PRG fillers.

Objectives: To evaluate the effect of acid erosion on different physical properties of resin composite with S-PRG (surface pre-reacted glass) fillers, by conducting simulations of intrinsic and extrinsic sources.

Materials And Methods: Cylindrical samples (Ø6 vs. 2 mm) of a conventional nanohybrid resin composite (Forma, Ultradent) and of a nanohybrid resin composite with S-PRG filler (Beautifil II, Shofu) were exposed to erosive cycling (5 days), based on (n=12) remineralizing solution (control); 0.

TiO nanotube-based nanotechnology applied to high-viscosity conventional glass-ionomer cement: ultrastructural analyses and physicochemical characterization.

This study characterized TiO nanotube (TiO-nt) ultrastructure and morphology, and the physicochemical impact on high-viscosity conventional glass-ionomer cement (GIC). TiO-nt was synthesized by the alkaline method (n = 3), assessed by scanning (SEM) and transmission electron microscope (TEM), and was added (3%, 5%, 7%-in weight) to KM (Ketac Molar EasyMix™). Analyses included: SEM; Energy-dispersive spectroscopy (EDS); Raman spectroscopy (RAMAN); Setting time with Gillmore needles (ST); Color (Co); Radiopacity (XR); Water sorption (WS); and solubility (SO).

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.

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).

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).

Can brushing with regular and whitening dentifrices influence changes in color and micromorphologic surfaces of ceramic brackets subjected to coffee staining?

The aim of the present study was to evaluate the influence of brushing with regular or whitening dentifrices on the change in color and micromorphologic surface of ceramic orthodontic brackets subjected to coffee staining. Fifty ceramic brackets were subjected to cycles of coffee staining followed by brushing according to the following groups (n = 10): C, control (no brushing); DW, brushing with distilled water; CT, brushing with Colgate Total 12 Clean Mint (regular toothpaste); COW, brushing with Colgate Optic White (containing 1% hydrogen peroxide); and CUWA, brushing with Close-Up White Attraction (containing blue covarine). The color of the brackets was assessed using the Commission Internationale de l'Eclairage (CIE) L*a*b* system at 5 different timepoints: prior to staining (baseline) and after 1, 7, 14, and 21 days of staining and brushing cycles.

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).

Color change after tooth bleaching with ozone and 10% ozonized carbamide peroxide for in-office use.

There is a constant search for bleaching treatments that can offer greater safety with fewer adverse effects, especially in the techniques performed in the office, which usually employ hydrogen peroxide in high concentrations (35% to 40%) that are not recommended by some international control agencies. This in vitro study evaluated the color change after tooth bleaching with the use of ozone and a 10% ozonized carbamide peroxide bleaching treatment for in-office use. Thirty molars were allocated (n = 10): three applications of ozone (1 hour every 3 days); three applications of 10% ozonized carbamide peroxide (1 hour every 3 days); 10% carbamide peroxide agent (8 hours a day for 7 days).

Phenolic extract of Libidibia ferrea inhibits dentin endogenous enzymatic activity depending on the adhesive system strategy.

This study evaluated the influence of Libidibia ferrea (Lf) extract used as dentin pretreatment on the resin-dentin bond strength stability and dentin endogenous enzymatic activity. The phytochemical profile (PP) of the Lf extract was evaluated by liquid chromatography; particle size, polydispersity index (PdI), and zeta potential (ZP) were evaluated by dynamic light scattering. The tested groups were ER-Scotchbond Universal (SBU) in the etch-and-rinse (ER) mode; ERLf-SBU in the ER mode + Lf after etching; SE- SBU in the self-etch (SE) mode; and LfSE-Lf before SBU in the SE mode.

Antimicrobial resistance of bacterial strains in patients undergoing orthodontic treatment with and without fixed appliances.

Objectives: To identify microorganisms isolated from patients wearing fixed orthodontic appliances and to evaluate the resistance of isolated bacterial strains to different antimicrobials.

Materials And Methods: Seventeen healthy patients wearing a fixed orthodontic appliance (group 1) and six nonwearers (group 2, control group) were evaluated. The biofilm that formed around the orthodontic brackets was collected, and the samples were then plated in a chromogenic medium (chromIDT, bioMérieux).

Physical, chemical, mechanical, and micromorphological characterization of dental needles.

Background: In anesthetic techniques, touching bones can cause needle bending. Theoretically, a needle should support such deflection without fracturing. However, it is possible that a needle may fracture depending on the quality and type of needle used.