Effect of sodium metabisulfite gel on the bond strength of dentin of bleached teeth.

Objective: This study aimed to evaluate the effect of the application of sodium metabisulfite (SMB) on the bond strength of bleached teeth.

Materials And Methods: The study was divided into two parts. The first part evaluated the application of various concentrations of SMB for 1 h prior to the completion of bonding procedures.

Influence of Enamel Thickness on Bleaching Efficacy: An In-Depth Color Analysis.

This study evaluated the influence of different enamel thicknesses and bleaching agents on treatment efficacy in-depth by spectrophotometry color analysis. Eighty bovine dental fragments were previously stained in black tea solution and randomly assigned into eight groups (n=10), 1.75mm dentin thickness and different enamel thicknesses as follows: 0.

Tooth enamel properties and morphology after microabrasion: an in situ study.

Aim: This study evaluated the effect of saliva on enamel after microabrasion with different microabrasive compounds under in situ conditions.

Methods: Enamel/dentin blocks (16 mm ) from bovine incisors were divided into nine groups (n = 19): one control group (no treatment), four groups treated with microabrasion using 35% phosphoric acid (H PO ) + pumice, and the last four groups treated with microabrasion using 6.6% hydrochloric acid (HCl) + silica.

Effects of Bleaching Agents Combined with Regular and Whitening Toothpastes on Surface Roughness and Mineral Content of Enamel.

Objective: The purpose of this study was to evaluate surface roughness and changes in the composition of enamel submitted to different bleaching protocols and toothbrushing with regular and whitening toothpastes.

Background Data: Bleaching treatment could promote morphological and chemical changes in enamel surface.

Methods: Enamel blocks were randomized into nine groups (n=10) according to the bleaching treatment (no bleaching, control group; 6% hydrogen peroxide, HP; or 10% carbamide peroxide, CP) and toothpaste used (placebo, PL; regular, R; or whitening dentifrice, W).

Enamel morphology after microabrasion with experimental compounds.

Background: Enamel microabrasion is an esthetic treatment for removing superficial stains or defects of enamel.

Aim: This study evaluated the roughness after enamel microabrasion using experimental microabrasive systems.

Materials And Methods: One hundred and ten samples (5 × 5 mm) were obtained from bovine incisors and divided into 11 groups (n = 10) in accordance with the treatment: Microabrasion using 6.

In vitro effects of hydrogen peroxide combined with different activators for the in-office bleaching technique on enamel.

Objective: The aim of this study was to evaluate the alteration of human enamel bleached with high concentrations of hydrogen peroxide associated with different activators.

Materials And Methods: Fifty enamel/dentin blocks (4 × 4 mm) were obtained from human third molars and randomized divided according to the bleaching procedure (n = 10): G1 = 35% hydrogen peroxide (HP - Whiteness HP Maxx); G2 = HP + Halogen lamp (HL); G3 = HP + 7% sodium bicarbonate (SB); G4 = HP + 20% sodium hydroxide (SH); and G5 = 38% hydrogen peroxide (OXB - Opalescence Xtra Boost). The bleaching treatments were performed in three sessions with a 7-day interval between them.

Enamel microabrasion: An overview of clinical and scientific considerations.

Superficial stains and irregularities of the enamel are generally what prompt patients to seek dental intervention to improve their smile. These stains or defects may be due to hypoplasia, amelogenesis imperfecta, mineralized white spots, or fluorosis, for which enamel microabrasion is primarily indicated. Enamel microabrasion involves the use of acidic and abrasive agents, such as with 37% phosphoric acid and pumice or 6% hydrochloric acid and silica, applied to the altered enamel surface with mechanical pressure from a rubber cup coupled to a rotatory mandrel of a low-rotation micromotor.

Influence of surface treatments on enamel susceptibility to staining by cigarette smoke.

Objectives: The purpose of this study was to evaluate the influence of remineralizing agents, including artificial saliva, neutral fluoride, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), on the susceptibility of bleached enamel to staining by cigarette smoke.

Study Design: Fifty bovine enamel blocks were randomly divided into five groups (n = 10): G1- bleaching; G2- bleaching and immersion in artificial saliva; G3- bleaching and application of CPP-ACP; G4- bleaching and application of neutral fluoride; and G5- untreated (Control). Teeth were bleached with 35% hydrogen peroxide and treated with the appropriate remineralizing agent.

Effectiveness of dental bleaching in depth after using different bleaching agents.

Objectives: This study evaluated the effectiveness of low- and high-concentration bleaching agents on enamel and deep dentin.

Study Design: Stained bovine incisors fragments were randomized placed into 10 groups (n=5), according to the sample thicknesses (2.0 mm or 3.

Efficacy of tooth bleaching with the prior application of a desensitizing agent.

Aim: In the present study, we evaluated the efficacy of bleaching on enamel and opposite dentin surfaces using 35% hydrogen peroxide (HP) with the prior application of a desensitizing agent.

Methods: Thirty bovine dental fragments, with thicknesses of 1 mm enamel and 1.75 mm dentin, were stained in a solution of black tea.

Effect of polymerization mode and time of adhesive system on microleakage in composite resin restorations.

Aim: To quantify the microleakage on restorations carried out with a two-step etch-and-rise adhesive system and nanofilled composite resin after thermal and mechanical loading cycling.

Methods: Ninety cavities were prepared on proximal surfaces of incisive teeth, and were randomly divided according to the photoactivation time (10, 20, or 30 s) and light-curing mode (Quartz Tungsten Halogen (QTH) lamps, 450 mW/cm(2); Light Emitting Diode (LED) second generation, 1100 mW/cm(2); or LED third generation, 700 mW/cm(2)) of an adhesive system (n = 10). Following restorative procedures and thermal and mechanical loading cycling, the samples were immersed in Methylene Blue for 2 h.

Esthetic and functional rehabilitation via reattachment of dental fragments.

Anterior teeth fractures are frequently encountered in clinical practice. The reattachment of dental fragments, if possible, is a conservative and effective technique, which is utilized in this case. This case presentation concerns an 18-year-old male patient with a root-crown fracture of the left maxillary central incisor, which involves the periodontal biologic space.

Influence of coffee and red wine on tooth color during and after bleaching.

Objective: The aim of this study was to evaluate the influence of coffee and red wine staining on tooth color during and after bleaching.

Materials And Methods: Blocks obtained from human molars were divided into 11 groups (n = 5) in accordance with the bleaching treatment-peroxide carbamide 10%, 15% or 20%-and in accordance with the stain therapy-coffee, wine or without staining (control). Color change analysis was performed by photo-reflectance using a spectrophotometer, during (3-times/week) and after (7, 15 and 30 days) the bleaching treatment.

Effect of curing light distance and different mouthwashes on the sorption and solubility of a nanofilled composite.

The aim of this in vitro study was to evaluate the sorption (Sp) and solubility (Sl) of a nanofilled composite (Filtek™ Z350) light-activated from the top in three curing light distances (0 mm, 3 mm and 6 mm) and immersed in three different mouthwashes (Plax Fresh Mint, Plax Alcohol Free, and Plax Whitening). Specimens (6 mm Ø and 1 mm height) were prepared (n = 5) and initially the degree of conversion (DC%) of discs was obtained by using a fourier transform infrared spectrometer. Then, the specimens were placed in a desiccator at 37°C and were weighed until a constant mass (m1) was obtained.

Effect of light polymerization time, mode, and thermal and mechanical load cycling on microleakage in resin composite restorations.

This study evaluated the effect of polymerization mode and time and thermal and mechanical loading cycling (TMC) on microleakage in composite resin restorations. One hundred and eighty cavities were prepared and randomly divided according to the light curing time (20, 40, or 60 s), modes (quartz-tungsten-halogen (QTH)-420 mW/cm(2), LED 2 (2nd degree generation)-1,100 mW/cm(2), or LED 3 (3rd degree generation)-700 mW/cm(2)), and TMC. Following standard restorative procedures, the samples were prepared for analysis in an absorbance spectrophotometer.

Evaluation of ultrasound and light sources as bleaching catalysts - an in vitro study.

Purpose: To evaluate the efficacy of tooth bleaching with high concentration agents, varying the catalyst sources and exposure times.

Materials And Methods: Stained human third molar fragments were randomized and placed into 8 groups (n = 5). G1: Whiteness HP Maxx (FGM, Joinville, SC, Brazil) 35% (HP)/5 min on enamel surface without external catalyst source; G2: HP/15 min without external catalyst association; G3: HP/5 min with Quartz Tungstein Halogen (QTH: Optilux 501C, Demetron/Kerr, Danbury, CT, USA) as a catalyst; G4: HP/15 min with QTH as a catalyst; G5: HP/5 min with LED/laser as a catalyst; G6: HP/15 min with LED/ laser as a catalyst; G7: HP/5 min with ultrasound as a catalyst; G8: HP/15 min with ultrasound as a catalyst.

Influence of chemical or physical catalysts on high concentration bleaching agents.

Objectives: The aim of this in vitro study was to evaluate the bleaching efficacy of high concentration bleaching agents activated by chemical or physical catalysts.

Materials And Methods: This study was divided into two parts. Part 1 evaluated the efficacy of tooth whitening after treatment with 35% hydrogen peroxide (Whiteness HP Maxx) that was activated by different light-curing units: halogen lamp (conventional and bleach mode) (Optilux 501C, Demetron/Kerr), LED first generation (Ultrablue IV, DMC), LED/diode laser (Ultrablue IV, DMC), LED second generation (Bluephase 16i, Ivoclar Vivadent), and no light source (control group).

Influence of previous acid etching on interface morphology and bond strength of self-etching adhesive to cavosurface enamel.

Objectives: The aim of this study was to evaluate the (1) bond strength of a etch-and-rinse and self-etching adhesive systems to cavosurface enamel, (2) influence of the previous acid etching with phosphoric acid 35% to the self-etching adhesive application on bond strength values, and (3) analysis of the cavosurface enamel morphology submitted to different types of conditioning, with the use of a scanning electronic microscope (SEM).

Methods: Twenty four human third molars were sectioned on mesio-distal direction, resulting in two slices. The specimens were ground flat with 600-grit aluminum oxide papers, and were randomly divided into three groups: Group 1 (etch-and-rinse adhesive system (control group)), Group 2 (self-etching adhesive), and Group 3 (self-etching adhesive with previous 35% phosphoric acid-etching for 15 s).

Advances in dental veneers: materials, applications, and techniques.

Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient.

Effect of surface sealants on microleakage of Class II restorations after thermocycling and long-term water storage.

Purpose: To evaluate interface degradation leading to marginal microleakeage in Class II restorations that had received an application of surface sealant at the tooth/restoration interface or not.

Materials And Methods: Eighty bovine incisors were used, and the teeth were split obliquely, 10 mm from the amelodentinal proximal junction, and finished with water abrasive papers to obtain a smooth, flat incisal surface. Cavities were made to simulate Class II preparations (8 mm high, 4 mm wide and 1.

Effects of mouthwashes on Knoop hardness and surface roughness of dental composites after different immersion times.

The aim of this in vitro study was to evaluate the effect of different mouthwashes on superficial roughness and Knoop hardness of two resin composites. Eighty specimens (6 mm Ø and 2 mm height) were prepared and divided into eight experimental groups (n = 10) according to the resin composites (4 Seasons and Esthet X), and storage solutions (G1 - Distilled water; G2 - Colgate Plax Overnight; G3 - Colgate Plax Alcohol Free; and G4 - Colgate Plax Whitening). The initial hardness and roughness readings (T1) were measured and then the specimens were stored in 2 mL of mouthwash for 12 h (T2) and 24 h (T3).

Effect of different light-curing modes on degree of conversion, staining susceptibility and stain's retention using different beverages in a nanofilled composite resin.

Statement Of Problem: It is unknown whether the staining pigment concentration would affect the color of composite resin and whether the absorption of the staining pigment is related to the degree of conversion (DC).

Purpose: The purpose of this study was to evaluate the effect of light-curing units (LCUs) on DC, superficial staining (ΔE), and pigment concentration (PC) in a nanofilled composite resin (Z350, 3M ESPE) using different beverages.

Materials And Methods: Specimens were polymerized for 20 seconds using four LCUs (N=50): quartz-tungsten-halogen (QTH)--450 mW/cm(2); laser (LAS)--300 mW/cm(2); second-generation light-emitting diode (LED)-1100 mW/cm(2); and third generation LED--700 mW/cm(2).

Influence of extended light exposure time on the degree of conversion and plasticization of materials used as pit and fissure sealants.

Aim: To evaluate the conversion and plasticization of fissure sealer materials, as influenced by extended curing time.

Methods: Twenty specimens (n=5) of a pit and fissure sealant and a flowable composite at two curing times (20 and 60 sec) were photocured with the Bluephase 16i light-emitting diode. The conversion was determined by Fourier transform infrared/attenuated total reflection spectroscopy 24 h after polymerization.

In vitro evaluation of the effectiveness of bleaching agents activated by different light sources.

Purpose: This study evaluated the efficacy of tooth whitening and color stability at different time periods after treatment.

Materials And Methods: Blocks obtained from human molars were divided into 15 groups (n = 5) by bleaching agents: 35% hydrogen peroxide (Whiteness HP and Opalescence Xtra) and 37% carbamide peroxide (Whiteness Super); and light sources: halogen lamp and plasma arc lamp (bleach mode), LED/diode laser, argon laser, and no light source. The efficacy of bleaching was measured using a spectrophotometer.

Influence of light curing and sample thickness on microhardness of a composite resin.

The aim of this in vitro study was to evaluate the influence of light-curing units and different sample thicknesses on the microhardness of a composite resin. Composite resin specimens were randomly prepared and assigned to nine experimental groups (n = 5): considering three light-curing units (conventional quartz tungsten halogen [QTH]: 550 mW/cm(2) - 20 s; high irradiance QTH: 1160 mW/cm(2) - 10 s; and light-emitting diode [LED]: 360 mW/cm(2) - 40 s) and three sample thicknesses (0.5 mm, 1 mm, and 2 mm).