Effect of finishing and polishing systems on surface roughness and color stability of aesthetic restorations exposed to staining solution.

The color and the surface roughness of aesthetic restorations are related to the clinical sucess and longevity of these treatments. Aim: This study evaluated the influence of finishing and polishing systems, and storage media on the surface roughness and color stability of aesthetic restorative composites. Materials and Method: Cylindrical specimens (n=10) were prepared and treated according to: 1.

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.

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.

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.

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.

Modeler liquids: Effect on the cohesive strength, color and staining resistance of stratified resin composite restorations.

Purpose: To evaluate the effect of filled and unfilled modeler liquids on the cohesive strength and color stability when applied in between the resin composite layers in the stratification technique and on the uppermost surface layer.

Methods: For the cohesive strength test (n= 10), 30 cylindrical samples were packed into a Teflon mold (6x2 mm) in 2 mm increments. Firstly, a dentin-shade resin composite (Empress Direct) was placed, followed by the accommodation of a body-shade resin composite (Filtek Z350 XT) and an enamel-shade resin composite (Estelite Omega).

Salivary, acidic and enzymatic degradation of resin composite subjected to different finishing and polishing systems.

Purpose: To evaluate the effect of different finishing and polishing systems on the surface roughness of a resin composite subjected to simulated saliva-, acid-, and enzyme-induced degradation.

Methods: 160 specimens (n= 40) were fabricated with Filtek Z350 XT nanofilled composite and analyzed for average surface roughness (Ra). The specimens were finished and polished using: AD - Al₂O₃-impreginated rubberized discs (medium, fine, and superfine grit, Sof-Lex); SD - silicon carbide and Al₂O₃-impregnated rubberized discs (coarse, medium and fine grit, Jiffy,); MB - 12- and 30-multiblade burs.

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.

Effect of simplified or multi-step polishing techniques on roughness and color stability of resin composites.

Purpose: To evaluate the impact of simplified or multi-step polishing techniques on the roughness, color, and susceptibility to staining of different resin composites.

Methods: Discs (Ø6 mm x 2 mm) were obtained from different resin composites [nanofilled (Z350XT), suprananofilled (Estelite Omega), and nanohybrid (Forma)]. The specimens (n= 15) were submitted to a simplified protocol using abrasive discs (Sof-Lex) and spiral discs (Diacomp Plus Twist), or a multi-step protocol using abrasive discs (Sof-Lex), abrasive points (Jiffy), silicon carbide brush and felt disc with diamond pastes (Diamond Polish).

Precision of polyether ether ketone (PEEK) or cobalt-chrome implant bar fit to implants after mechanical cycling.

Unlabelled: Based on its mechanical properties, PEEK (polyether-ether-ketone) might be useful in restorative procedures. In oral rehabilitation, its viability has been studied mainly for prostheses and dental implants.

Aim: The aim of this study was to evaluate the fit accuracy of dental implant bars made of either PEEK or cobalt-chrome submitted to cycling mechanics.

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.

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.

Smoothness provided by a one-step finishing and polishing system and its maintenance after 12-month aging.

Purpose: To evaluate the smoothness provided by a one-step finishing and polishing system and its maintenance after hydrothermal aging and brushing of a nanofilled resin composite.

Methods: 96 samples of the nanofilled composite Filtek Z350 XT were fabricated, which, after initial average roughness (Ra) analysis, were randomly distributed into three groups, according to the selected finishing and polishing system. The multi-step systems Sof-Lex (aluminum oxide discs) and Jiffy (bullet-shaped abrasive rubbers), and the one-step system OneGloss (bullet-shaped abrasive rubber) were used.

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.

The potential of salivary albumin to degrade composite resin.

Unlabelled: Albumin is a salivary enzyme capable of cleaving ester linkages and catalyzing degradation of resin-based dental materials. However, the effect of concentration-dependent esterolytic action on composite resins as yet remains unexplored.

Aim: The purpose of this study was to evaluate whether artificial saliva formulations with different concentrations of albumin affected the surface roughness, flexural strength and microhardness of a composite resin.

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.

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).

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).

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.