Thermal effects caused by the association of hybrid light and incorporation of titanium dioxide into 37% carbamide peroxide for dental bleaching.

This study monitored the thermal changes in the pulp chamber and on the buccal surface of teeth during in-office bleaching with 37% carbamide peroxide (CP) either with or without the incorporation of titanium dioxide (TiO) and with or without activation with a hybrid light (HL). A total of 50 bovine incisors were prepared and randomly separated into 5 treatment groups (n = 10): 35% hydrogen peroxide (HP); CP; CP + HL; CP + TiO; and CP + TiO + HL. The bleaching gels were applied for 30 minutes.

Effect of polishing systems on the roughness, color, and staining of conventional and bulk-fill resin composites with and without S-PRG filler.

Objective: To evaluate the effect of polishing systems on the color and roughness of conventional and bulk-fill nanofilled resins, compared to conventional and bulk-fill nano-hybrid resins with S-PRG fillers.

Materials And Methods: Discs (n = 12) were fabricated from the following resin composites: conventional nanofilled resin (Filtek Z350 XT, 3 M), bulk-fill nanofilled resin (Filtek One Bulk-Fill, 3 M), conventional nano-hybrid resin with S-PRG fillers (Beautifil II LS, Shofu), and bulk-fill nano-hybrid resin with S-PRG filler (Beautifil Bulk Restorative, Shofu). Polishing was conducted using multi-grit aluminum oxide abrasive discs (Sof-Lex Pop On, 3 M) or a single-grit aluminum oxide tip (OneGloss, Shofu).

Occlusion, acid resistance, and elemental characterization of dentin treated with desensitizing agents.

The objective of this study was to evaluate the occlusion potential of in-office desensitizing agents, and characterize the human dentin elements after acid exposure. Twelve human dentin discs were sectioned into four specimens each, and randomized into treatments (n = 20): no treatment (negative control); no treatment and 6% citric acid exposure (positive control); application of Gluma desensitizer (Heraeus Kulzer) or PRG Barrier Coat (Shofu), followed by 6% citric acid exposure. Occlusion and dentin surface characteristics were determined by scanning electron microscopy (SEM, n = 10), and elemental composition (at%), by energy-dispersive X-ray spectroscopy (EDS, n = 10).

Impact of polyethylene fiber-reinforced composite resin and thermomechanical cycling on dentin bond strength.

This study evaluated the microtensile bond strength (μTBS) and fracture pattern of direct composite resin reinforced with polyethylene fiber (Ribbond®) on dentin substrate after thermomechanical cycling (TMC). Dentin blocks (dentin thickness=2 mm) were obtained from forty human third molars and randomly divided into four groups (n=10) according to type of restoration (composite resin with or without Ribbond®) and to whether they were or were not subjected to TMC (100,000 cycles of 50 N / 2 Hz / 1-minute baths of 5 and 55ºC). The 1-mm-thick square-shaped specimens were submitted to μTBS testing in a universal testing machine at 0.

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 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.

Objective assessment of simulated non-carious cervical lesion by tridimensional digital scanning - An in vitro study.

Objective: Clinical assessment of progression of non-carious cervical lesions (NCCLs) is currently based on subjective methods. We hypothesize that 3D digital intraoral scanners (IOS) can provide quantitative outcomes for objective measuring and monitoring of NCCLs. This in vitro study verified the reliability of IOS to monitor dental structure loss of simulated NCCLs, in comparison to a reference bench-top 3D optical profilometer (BTS).

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).

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.

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.

Association of Non-carious Cervical Lesions with Oral Hygiene Aspects and Occlusal Force.

Aim: The purpose of this case-control (CT) study was to investigate the association between the presence of non-carious cervical lesions (NCCLs) with occlusal force and other potential risk factors.

Materials And Methods: Thirty-nine participants with NCCLs [cases (CS)] and 39 with no NCCLs [control (CT)] attending the dental clinic of the Faculdades Integradas São Pedro (FAESA), located in Brazil, were enrolled in this study. Information was collected through anamnesis, clinical examination, and a questionnaire addressing aspects related to tooth brushing, dentifrice, and mouthwash use.

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.