Evolution of roughness and optical properties of resin composites submitted to whitening toothpastes-cigarette smoking cycling.

Purpose: To evaluate the effect of cycling whitening toothpaste with cigarette smoking (WTCS) on the evolution of roughness, color, translucency, and gloss of microfilled, microhybrid, and nanofilled resin composites.

Methods: 15 specimens of Durafill - DVS, Empress Direct - ED, and Z350 - FZ were divided into three groups according to the toothpastes:: conventional, control group, (Colgate - C) and Whitening (Colgate Luminous White - CW and Oral B 3D White - OW) and roughness, color, translucency, and gloss were evaluated before and after the specimens were submitted to WTCS for 8 weeks. Data were analyzed by two-way ANOVA, 3-way repeated measures ANOVA, and Tukey HSD post hoc test (α= 0.

Evaluation of Recementation Protocols for Dislodged Glass Fiber Posts.

Purpose: To evaluate different protocols for recementation of dislodged glass fiber posts (GFPs).

Materials And Methods: The root canals of 50 bovine incisors were prepared to receive GFPs that were conditioned with 24% hydrogen peroxide, silanized, and cemented with a self-adhesive resin cement. After light curing, the specimens were submitted to a pullout test.

Glass fiber posts relining: can composite opacity influence retention to root canal dentin?

This study aimed at evaluating the influence of glass-fiber post (GFP) relining with composites of different opacities on resin cement layer thickness (CLT), bond strength (BS) to root dentin, and resin cement degree of conversion (DC%). Standardized roots of 52 bovine incisors had their canals prepared and were distributed into 4 groups (n = 10 for CLT and BS; n = 3 for DC%) according to the post used: WP3 (Control)-Whitepost DC3; groups DE, EN and TR-Whitepost DC0.5 relined, respectively, with dentin, enamel, and translucent shade composites.

Antimicrobial potential of resin matrices loaded with coffee compounds.

This study evaluated the biological behavior of the coffee compounds Trigonelline (T), chlorogenic acid (C), and nicotinic acid (N), correlating with their release from a resin matrix. Minimum inhibitory concentration (MIC) was evaluated against Streptococcus mutans UA159, and cytotoxicity was assessed by methyl tetrazolium salt on OD-21 cells. Resin matrices (bisphenol A-glycidyl-dimethacrylate/triethylene glycol-dimethacrylate 70/30 wt%, camphorquinone/ethyl 4-dimethyl aminobenzoate 0.

Development and characterization of biological bovine dentin posts.

This study aimed at evaluating the use of biological dentin post (BDP), achieved by milling bovine root, through the analyses of mechanical and optical properties. BDPs were compared to a glass fiber post (GFP) in the following tests (n = 10): a) elastic modulus (E) and flexural resistance (σ) by three point bending test; b) fracture resistance (FR) by compressive load at 45° and failure pattern; c) light transmitting (LT) ability and their influence on the resin cement's degree of conversion (DC%); d) bond strength (BS) by push-out test and failure pattern. Bovine teeth were decoronated and root length was standardized at 14 mm.

Can the Use of a Warm-Air Stream for Solvent Evaporation Lead to a Dangerous Temperature Increase During Dentin Hybridization?

Purpose: To analyze the effect of a warm-air stream for solvent evaporation on the temperature rise in the pulp chamber during dentin hybridization.

Materials And Methods: Dentin disks with thicknesses of 0.5, 1.

Effect of Calcium Hydroxide on Bonding Performance of an Experimental Self-etch Adhesive.

Purpose: To investigate the effect of Ca(OH)2 concentration on pH neutralization, degree of conversion (DC%), and bonding performance of experimental self-etch adhesives (SEAs).

Materials And Methods: Four different concentrations of Ca(OH)2 (0 wt%, 1 wt%, 2 wt%, and 4 wt%) were added to the bond of an experimental two-step SEA consisting of primer (10-MDP [30 wt%], TEG-DMA [30 wt%], ethanol [35 wt%], water [5 wt%], camphorquinone [0.5 wt%], and tertiary amine [0.

Can whitening toothpastes maintain the optical stability of enamel over time?

Besides the effects on the health of individuals, cigarette smoking can also interfere with the appearance of their teeth. To evaluate the effect of cigarette smoking-toothbrushing-cycling (CSTC) with whitening toothpastes on the roughness and optical behavior of bovine enamel for eight weeks. Thirty bovine dentin/enamel discs, 8.

Characterization of an experimental resin composite organic matrix based on a tri-functional methacrylate monomer.

This study evaluated the potential of a tri-functional monomer (trimethylolpropane trimethacrylate -TMPTMA) for inclusion in a dental composite organic matrix. Initially, four ternary matrixes with different concentrations (wt%) of bi-functional monomers [BisGMA (G), Bis-EMA (E) and TEGDMA (T)] were analyzed: GET523, GET532, EGT523 and EGT532 (the numbers (n) represent n×10 wt% of each monomer). The following properties were evaluated: degree of conversion, flexural strength, elastic modulus, hardness, absorption, solubility, diffusion coefficient of water and crosslink density.

Influence of organic acids present in oral biofilm on the durability of the repair bond strength, sorption and solubility of resin composites.

Purpose: To evaluate the repair bond strength after storage in water, lactic and propionic acid after 7 days and 6 months and the sorption and solubility of resin composites used.

Methods: Five cylinders of each resin composite (microhybrid, nanofilled and silorane-based composite) were prepared. Specimens were aged with thermocycling (5 and 55°C) 5,000 times.

Marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS).

Unlabelled: Marginal integrity is one of the most crucial aspects involved in the clinical longevity of resin composite restorations.

Objective: To analyze the marginal integrity of restorations produced with a model composite based on polyhedral oligomeric silsesquioxane (POSS).

Material And Methods: A base composite (B) was produced with an organic matrix with UDMA/TEGDMA and 70 wt.

Can cement film thickness influence bond strength and fracture resistance of fiber reinforced composite posts?

Objectives: This study compared the influence of cement film thickness (CFT) on bond strength (BS) and fracture resistance (FR) of fiber-reinforced composite (FRC) posts to root canal.

Materials And Methods: One hundred bovine incisors were used for BS and FR analysis (n = 10) and distributed into five experimental groups according to FRC post diameters (WhitePost DC no. 0.

Effects of different surface treatments on bond strength of an indirect composite to bovine dentin.

Background: Several surface treatments could be used to improve the bond strength (BS) between indirect composites and cement.

Aim: To evaluate the BS of an indirect composite submitted to different surface treatments, cemented to bovine dentin.

Settings And Design: One hundred and fifty conical cavities were prepared in slices of bovine dentin and bulk filled with the composite.

Degradation of resin composites in a simulated deep cavity.

The aim of this study was to analyze the sorption and solubility of a nanofilled (Filtek Z350) and a midifilled (Filtek P60) resin composite in oral environment-like substances, in a simulated deep cavity. A cylindrical cavity prepared in a bovine incisor root was incrementally filled with resin composites. The obtained resin composite cylinders were cut perpendicularly to the axis to obtain 1-mm-thick discs that were divided into fifteen groups (n=5) according to depth (1, 2, 3, 4 and 5 mm) and immersion media (distilled water - DW, artificial saliva - AS and lactic acid - LA).

Longitudinal evaluation of simulated toothbrushing on the roughness and optical stability of microfilled, microhybrid and nanofilled resin-based composites.

Objectives: The aim of this study was to evaluate the influence of simulated toothbrushing over ten weeks on the roughness and optical stability (colour, translucency and gloss) of microfilled - Mf (Durafil VS), microhybrid - Mh (Empress Direct) and nanofilled - Nf (Z 350) resin-based composites (RBC).

Methods: The roughness, colour, translucency and gloss of each RBC were measured before and after storage in distilled water (DW) and propionic acid (PA) for ten weeks. The specimens were removed from the media each week, submitted to toothbrushing simulation and the properties measured.

Long-term degradation of resin-based cements in substances present in the oral environment: influence of activation mode.

Unlabelled: Indirect restorations in contact with free gingival margins or principally within the gingival sulcus, where the presence of organic acids produced by oral biofilm is higher, may present faster degradation of the resin-based cement pellicle.

Objectives: To investigate the degradation of four resin-based cements: Rely X ARC (R), Variolink II (V), Enforce (E) and All Cem (A), after immersion in distilled water (DW), lactic acid (LA) and artificial saliva (AS) and to analyze the influence of the activation mode on this response.

Material And Methods: Two activation modes were evaluated: chemical (Ch) and dual (D).

Influence of organic acids present in the oral biofilm on the microtensile bond strength of adhesive systems to human dentin.

This study evaluated the influence of organic acids present in the oral biofilm on the microtensile bond strength (μTBS) of adhesive systems to human dentin. Sixty occlusal dentin surfaces were wet ground with 600 grit SiC abrasive paper and divided into four groups according to the adhesive systems: Scotchbond Multipurpose (SMP), Adper Single Bond 2, Adper Scotchbond SE (ASE), and Clearfill SE Bond (CSE). After the adhesive systems were applied, a block of resin composite was built up on the dentin surfaces.

A critical analysis of the degree of conversion of resin-based luting cements.

Objective: This study analyzed the degree of conversion (DC%) of four resin-based cements (All Ceram, Enforce, Rely X ARC and Variolink II) activated by two modes (chemical and dual), and evaluated the decrease of DC% in the dual mode promoted by the interposition of a 2.0-mm-thick IPS Empress 2 disc.

Material And Methods: In the chemical activation, the resin-based cements were prepared by mixing equal amounts of base and catalyst pastes.

The diffusion kinetics of a nanofilled and a midifilled resin composite immersed in distilled water, artificial saliva, and lactic acid.

This study investigated the diffusion kinetics of a nanofilled (Filtek Z350) and a midifill (Filtek P60) resin composite immersed in distilled water, artificial saliva and lactic acid. Resin composite specimens were desiccated, immersed in the media, weighed at suitable time intervals until they reached sorption equilibrium and were then desiccated again. Sorption and solubility (µg/mm(3)) were calculated based on ISO 4049:2000(E).

The effect of mouthrinses on salivary sorption, solubility and surface degradation of a nanofilled and a hybrid resin composite.

This in vitro study evaluated the effect of mouth rinses on salivary sorption (Sp), solubility (Sl) and surface degradation of a nanofilled (Z350) and hybrid (P60) resin composite. Specimens (6 mm in diameter and 1 mm thick) of a nanofilled and hybrid resin composite were immersed in artificial saliva at 37 degrees C for seven days. Twice a day, the samples (n = 5) were immersed in 20 ml of three mouth rinses: Listerine, Plax Mint and Plax.

Influence of the degree of dentine mineralization on pulp chamber temperature increase during resin-based composite (RBC) light-activation.

Objectives: To analyse the influence of the degree of dentine mineralization on the pulp chamber temperature increase during composite light-activation.

Methods: Dentine discs (2mm thick) obtained from recently extracted teeth or those with extensive dentine sclerosis were analysed by FT-IR spectrometry in order to choose the two discs with the greatest difference in the degree of mineralization. A model tooth was set up with the dentine discs between a molar with the pulp chamber exposed and a crown with a standardized class II cavity.

Influence of post-cure treatments on hardness and marginal adaptation of composite resin inlay restorations: an in vitro study.

Objectives: The purpose of this study was to evaluate the Vickers hardness number (VHN) and the in vitro marginal adaptation of inlay restorations of three hybrid composite resins (Filtek Z250, Opallis and Esthet-X) subjected to two post-cure treatments.

Material And Methods: For the microhardness test, three different groups were prepared in accordance with the post-cure treatments: control group (only light cure for 40 s), autoclave group (light cure for 40 s + autoclave for 15 min at 130 masculineC); and microwave group (light cure for 40 s + microwave for 3 min at 450 W). To assess the marginal adaptation, the composite resin was inserted incrementally into a mesial-occlusal-distal cavity brass mold and each increment light-cured for 40 s.

Relationship between the degree of conversion, solubility and salivary sorption of a hybrid and a nanofilled resin composite.

This study analyzed the relationship between the degree of conversion (DC), solubility, and salivary sorption of a hybrid (Filtek P 60) and a nanofilled resin composite (Filtek Supreme), and evaluated the influence of the light-activation mode on these properties. Two light-activation modes were used: Conventional (C; 850 mW/cm(2) for 20 s) and Soft-start (SS; 100-1,000 mW/cm(2) for 10 s + 1,000 mW/cm(2) for 10 s). The DC (%) was evaluated by FT-Raman spectroscopy.

Degree of conversion and plasticization of dimethacrylate-based polymeric matrices: influence of light-curing mode.

This study analyzed the correlation between the degree of conversion (DC) and the plasticization (P) of experimental dimethacrylate-based polymeric matrices. Six polymeric matrices produced with Bis-GMA (G), UDMA (U) and TEGDMA (T) dimethacrylate monomers were studied: G, U, GT55, GT73, GU55, GU73 - (55 = 50/50wt% and 73 = 70/30wt%). Photoactivation was induced by camphoroquinone/ethyl N, N-dimethyl-4-aminobenzoate.