A method for calculating the compliance of bonded-interfaces under shrinkage: validation for Class I cavities.

Objective: The compliance for tooth cavity preparations is not yet fully described in the literature. Thus, the objectives were to present a finite element (FE) method for calculating compliance and to apply this to peak shrinkage stress regions in model cavities restored with resin-composite.

Methods: Three groups of FE-models were created, with all materials considered linear, homogeneous, elastic and isotropic: (a) a pair of butt-joint bonded cubic prisms (dentin/resin-composite), with dentin of known compliance (0.

Effect of light irradiation on tooth whitening: enamel microhardness and color change.

The aim of this study was to evaluate the influence of light exposure associated with 35% hydrogen peroxide (Pola Office, SDI, Melbourne, Vic., Australia) or 15% hydrogen peroxide (BriteSmile, Discus, Culver City, CA, USA) on the microhardness and color changes of bovine enamel. Experimental groups were Britesmile + Light (BL) (15% hydrogen peroxide + plasm arc; 4 x 20 minutes), Britesmile + No Light (BN) (BL, no light), Pola office + Light (PL) (35% hydrogen peroxide + LED; 4 x 8 minutes), and Pola office + No light (PN) (PL, no light).

Chemical versus conventional caries removal techniques in primary teeth: a microhardness study.

The aim of this in vitro study was to assess the remaining dentinal surface after carious tooth tissue removal with a low speed conventional bur and two chemomechanical methods, (Papacárie and Carisolv), using the microhardness test. It was concluded that the hardness of the remaining dentin after carious tissue removal was lower than that obtained on healthy dentin, without significance between the different means of carious tissue removal (p<0.05).

Microtensile bond strength of photoactivated and autopolymerized adhesive systems to root dentin using translucent and opaque fiber-reinforced composite posts.

Statement Of Problem: The use of fiber-reinforced composite resin posts in endodontically treated teeth has increased. However, selecting an adhesive system that provides reliable and long-lasting bonding to root canal dentin remains difficult.

Purpose: This study evaluated the microtensile bond strength of 2 adhesive systems to root dentin and 2 different fiber-reinforced composite resin posts.

Composite depth of cure obtained with QTH and LED units assessed by microhardness and micro-Raman spectroscopy.

This study analyzed the depth of cure of a composite assessed by microhardness and the degree of conversion as a function of the light cure unit (LCU) used. Two light cure units, one LED (Ultraled-Dabi Atlante) and one quartz-tungsten-halogen (QTH, Optilux 401-Demetron) unit were used to cure 4.0 x 4.

Shear versus micro-shear bond strength test: a finite element stress analysis.

Objectives: This study aimed at comparing the stress distribution in shear and micro-shear test set-ups using finite element analysis, and suggesting some parameter standardization that might have important influence on the results.

Methods: Two-dimensional plane strain finite element analysis was performed using MSCPatran and MSCMarc softwares. Model configurations were based on published experimental shear and micro-shear test set-ups and material properties were assumed to be isotropic, homogeneous and linear-elastic.

Effect of light-activation methods and water storage on the flexural strength of two composite resins and a compomer.

The present study evaluated the flexural strength of three composite resins recommended for direct esthetic restorations: a polyacid modified composite (Dyract AP), a unimodal composite resin (Filtek Z250) and a hybrid composite resin (Point 4). The variation factors, apart from the type of composite resin, were the light activation method and the water storage period. The composite resins were light-cured in continuous mode (40 s, 500 mW/cm2) or in ramp mode (0-800 mW/cm2 for 10 s followed by 30 s at 800 mW/cm2) and stored for 24 hours or 30 days in distilled water at 37 degrees C.

Influence of rubber dam isolation on human pulp responses after capping with calcium hydroxide and an adhesive system.

Objective: The objective was to evaluate the influence of rubber dam isolation on the response of human pulps capped with calcium hydroxide and an adhesive system.

Methods And Materials: Direct pulp capping was performed in 40 caries-free human premolars scheduled for extraction as part of orthodontic treatment. The teeth were randomly divided into 8 groups (n = 5) according to the combination of treatment factors: capping agent (adhesive resin or calcium hydroxide), isolation (rubber dam or cotton pellets only), and period of evaluation (30 or 60 days).

A novel method to obtain microtensile specimens minimizing cut flaws.

Cutting procedures conventionally used for microtensile specimens' preparation induce mechanical stress and attrition, leading to cracks in dental structure. Enamel is mainly affected due to its high module of elasticity and brittleness. As an alternative to the conventional diamond saw, a diamond wire was used for cutting.

The effect of specimen dimensions on the flexural strength of a composite resin.

Unlabelled: PUORPOSE: The aim of this study was to evaluate the effect of specimen dimensions on the flexural strength of a composite resin (Heliomolar RO).

Methods: The different dimensions tested - length x width x height (mm) were: 25x2x4; 25x2x2 (ISO 4049); 15x2x2; 10x2x2 and 10x2x1. Light-curing was performed at 600 mW/cm² for 40s, three times along the 25mm specimens, twice along 15mm specimen and once for the 10mm specimens.

Microtensile bond strength of light- and self-cured adhesive systems to intraradicular dentin using a translucent fiber post.

This study evaluated the bond strength of a light- and self-cured adhesive system to different intraradicular dentin areas (cervical, middle and apical thirds). Twenty single-rooted teeth were instrumented and their roots were prepared to receive a #2 translucent fiber post (Light Post). The root canals were irrigated with 0.

Adverse effects of human pulps after direct pulp capping with the different components from a total-etch, three-step adhesive system.

Objectives: The objective was to evaluate the response of human pulps capped with different components from a total-etch three-step adhesive system.

Methods: Direct pulp capping was performed in 25 caries-free human premolars scheduled for extraction due to orthodontic treatment. The teeth were randomly divided in five groups, and capped with the following materials: Group 1-acid+primer+adhesive were used as recommended; Group 2-only primer was applied; Group 3-only bonding resin (light-cured for 10s); Group 4-only composite resin (light-cured for 40s); Group 5-calcium hydroxide.

The effect of long-term storage on the microleakage of composite resin restorations: qualitative and quantitative evaluation.

The aim of this study was to evaluate the influence of storage periods of 24 hours and 3 months on the microleakage of class II cavities. Two methods of assessing microleakage were also compared. Class II cavities were prepared in sound human molars.

The influence of handling on the elasticity of addition silicone putties.

The handling of vinyl polysiloxane (addition silicone) impression putties with latex gloves is said to interfere with the setting of these impression materials. The aim of this study is to evaluate the effect of handling techniques on the setting of vinyl polysiloxane impression putties using several types of gloves. The setting of these materials was evaluated by means of an elasticimeter.

Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release.

Objectives: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition.

Methods: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489.