Abrasion resistance of direct and indirect resins as a function of a sealant veneer.

Background: Abrasive wear is one of the most common type of wear that not only affect teeth, as also dental restorations. Thus to investigate one of the etiological factors as tooth brushing procedure is clinical relevant in order to select the best material combination that may prevent damage of resin dental restoration's abrasion.

Aims: This study evaluated the influence of tooth brushing on mass loss and surface roughness of direct Venus (Vs) and indirect Signum (Sg) resin composites, with and without a surface sealant, Fortify (F).

Degree of chronic orofacial pain associated to the practice of musical instruments in orchestra's participants.

Objective: The practice of playing musical instruments can affect structures of the head, neck, mouth, and the masticatory system. The aim of this study was to obtain information regarding the prevalence of orofacial pain in musicians according to the type of instrument they play, by applying a specific questionnaire.

Materials And Methods: One hundred and seventeen musicians of Sao Paulo state's orchestras participated in this study.

Surface agents' influence on the flexural strength of bilaminated ceramics.

The objective of this study was to evaluate the influence of different surface agents on the flexural strength of a ceramic system. Eighty bar-shaped specimens of zirconia were divided into four groups according to the agent to be used: group Control--to be cleaned with alcohol; group VM9--application of a fluid layer of porcelain; group Effect Bonder--application of a bonding agent; and group Coloring Liquid--application of coloring liquid. All specimens received the porcelain application by the layering technique and were then subjected to thermocycling.

In Vitro assessment of dentin erosion after immersion in acidic beverages: surface profile analysis and energy-dispersive X-ray fluorescence spectrometry study.

The aim of this study was to investigate the effects of some acidic drinks on dentin erosion, using methods of surface profile (SP) analysis and energy-dispersive X-ray fluorescence spectrometry (EDXRF). One hundred standardized dentin slabs obtained from bovine incisor roots were used. Dentin slabs measuring 5x5 mm were ground flat, polished and half of each specimen surface was protected with nail polish.

Clinical evaluation of two packable resin-based composite restorations: a three-year report.

This randomized clinical trial sought to evaluate the performance of two packable composites over a period of 36 months. A total of 39 Class I and II restorations were placed in the permanent teeth of 20 patients. Using United States Public Health Services criteria, two investigators evaluated the restorations immediately after placement and again after 12 and 36 months, examining color match, marginal discoloration, marginal integrity, recurrent caries, proximal contact, anatomical shape, surface texture, and postoperative sensitivity.

Intrapulpal temperature variation during bleaching with various activation mechanisms.

Objectives: The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35% hydrogen peroxide using different sources of activation.

Material And Methods: Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12): (G1) Control - Bleaching gel without light activation, (G2) Bleaching gel + halogen light, (G3) Bleaching gel + LED, (G4) Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel.

Temperature variation caused by high-intensity LED curing lights in bovine dentin.

This study sought to evaluate the temperature variations in bovine dentin when cured with high-intensity LED appliances and quartz-tungsten-halogen (QTH) appliances. Forty-five slices of bovine dentin (0.7 mm thick) were divided into three groups.

Polymerization efficiency of high-intensity LEDs with different exposure times.

This study compared two high-intensity light-emitting diode (LED) appliances to a quartz-halogen-tungsten (QTH) appliance and measured their ability to polymerize resin composite efficiently. Eighty-four test specimens (2 mm x 5 mm) were made of resin composite and exposed to one of the two LED appliances for 10, 20, or 40 seconds; the QTH appliance was used as a control group for 40 seconds. It was concluded that using the high-intensity LEDs for 20 seconds produced microhardness similar to that produced by using the QTH appliance for 40 seconds, but the high intensity LEDs did not improve depth of cure.

Knowledge of general dentists in the current guidelines for emergency treatment of avulsed teeth and dental trauma prevention.

A high prevalence of dental trauma exists and its effects on function and esthetics deserve the attention of general dentists. The aim of this study was to assess the level of general dental practitioners' (GDPs) knowledge about guidelines for dental avulsion and its prevention using a questionnaire. The 21-item questionnaire was distributed among 264 GDPs and the survey was realized between August-November 2006.

Penetration of 35% hydrogen peroxide into the pulp chamber in bovine teeth after LED or Nd:YAG laser activation.

This aim of the present study was to evaluate the pulp chamber penetration of 35% hydrogen peroxide activated by LED (light-emitting diode) or Nd:YAG laser in bovine teeth, after an in-office bleaching technique. Forty-eight bovine lateral incisors were divided into four groups, acetate buffer was placed into the pulp chamber and bleaching agent was applied as follows: for group A (n = 12), activation was performed by LED; for group B (n = 12), activation was performed by Nd:YAG laser (60 mJ, 20 Hz); group C (n = 12) received no light or laser activation; and the control group (n = 12) received no bleaching gel application or light or laser activation. The acetate buffer solution was transferred to a glass tube and Leuco Crystal Violet and horseradish peroxidase were added, producing a blue solution.

Influence of cavity preparation and curing method on the marginal seal of resin composite restorations: an in vitro evaluation.

Objective: To evaluate the influence of cavity design and photocuring method on the marginal seal of resin composite restorations.

Method And Materials: Seventy-two bovine teeth were divided into 2 groups: group 1 received box-type cavity preparations, and group 2 received plate-type preparations. Each group was divided into 3 subgroups.

The effect of adhesive systems on the pullout strength of a fiberglass-reinforced composite post system in bovine teeth.

Purpose: To evaluate the pullout strength of a glass fiber-reinforced composite post (glass FRC) cemented with three different adhesive systems and one resin cement. The null hypothesis was that pullout strengths yielded by the adhesive systems are similar.

Materials And Methods: Thirty bovine teeth were selected.

Effects of dentin collagen removal on microleakage of bonded restorations.

Purpose: To evaluate the effects of removing dentin collagen exposed by acid etching on the microleakage of bonded restorations with and without flowable composite application and submitted to thermocycling and long-term water storage.

Materials And Methods: Standardized Class V cavities were prepared in 180 bovine incisors. They were randomly assigned to three groups according to the adhesive technique used.

Sealing evaluation of the cervical base in intracoronal bleaching.

Discoloration of non-vital teeth is an esthetic deficiency frequently requiring bleaching treatment. The purpose of this study was to evaluate in vitro the cervical base efficacy in order to prevent or to minimize the leakage along the root canal filling and into the dentinal tubules. Thirty-eight extracted single-root human teeth were used, which were biomechanically prepared, filled, and divided into three experimental groups: G1, a cervical base was applied (3 mm of thickness) below the cemento-enamel junction, with resin-modified glass-ionomer cement (Vitremer); G2, the base was done with glass-ionomer cement (Vidrion R); and G3 (Control), did not receive any material as base.