Analysis of the mandibular molars root canals morphology. Study by computed tomography.

This study aimed to analyze the root and root canal morphology of mandibular first and second molars using CBCT images. A total of 2,400 mandibular molars exams were selected from 600 patients aged between 18 and 75 years. The number of roots, number of root canals, and root canal configuration according to the Vertucci classification were verified.

Bleaching effect of violet LED of 405-410 nm on stained endodontically treated teeth.

Aim: To evaluate in vitro the whiteness index (WID) and the whiteness index variation (ΔWID), as well as the color stability of stained endodontically treated teeth after bleaching with violet LED (VL) and with hydrogen peroxide 35% (HP) associated or not to VL.

Methods: Twenty-four lower incisors were selected. The color was measured using a spectrophotometer at the following times: baseline, after staining, bleaching, and thermocycling, to determine the whiteness index and variation (WID and ΔWID).

Effect of Er:YAG laser irradiation and chitosan biomodification on the stability of resin/demineralized bovine dentin bond.

Objective: The purpose of this study was to evaluate the effect of Er:YAG laser for selective removal of carious lesion, followed by biomodification with chitosan on the microtensile bond strength (µTBS), adhesive interface, dry mass loss and hydroxyproline release (HYP).

Methods: Artificial lesions were created in 104 bovine dentin blocks. Blocks were divided according to caries removal method: bur or Er:YAG laser.

Effect of Er:YAG laser on enamel demineralization around restorations.

This study evaluates in situ the effect of erbium-doped yttrium aluminum garnet (Er:YAG) laser parameters on the development of caries-like lesions adjacent to dental restorations. One hundred fifty bovine enamel slabs were randomly allocated among 15 volunteers. The specimens were subdivided into ten groups: nine experimental groups prepared with Er:YAG laser (300 mJ output, frequency of 2, 4 or 6 Hz, water flow rate of 2.

Microhardness of intracoronal dentin exposed to bleaching and fluoride treatment.

Objectives: The aim of this study was to assess the surface microhardness (SMH) of intracoronal dentin exposed to 38% hydrogen peroxide (HP) light-activated or not and to 2% sodium fluoride gel (F2%) or 5% varnish (F5%).

Study Design: Intracoronal dentin specimens were exposed to bleaching (B), bleaching and light activation (BL), or no bleaching (NB), followed by F2%, F5%, or no exposure (NF). SMH test was performed.

Effect of Er:YAG laser on tensile bond strength of sealants in primary teeth.

Purpose: The purpose of this in vitro study was to evaluate the tensile bond strength of sealants in primary molars after the surface pretreatment with an Er:YAG laser.

Methods: Thirty primary molars were selected, and their roots were removed. Crowns were embedded in polyester resin and enamel surfaces were flattened.

Temperature changes in the deciduous pulp chamber during cavity preparation with the Er:YAG laser.

Purpose: The purpose of this in vitro study was to evaluate the temperature changes in the pulp chambers of deciduous molars during cavity preparation with an Er:YAG (erbium substituted: yttrium aluminium garnet) laser.

Methods: Two cavities were prepared in 14 maxillary deciduous molars: one with the Er:YAG laser and other with a diamond bur using a high-speed handpiece (control), providing 4 groups with 7 cavities each. The laser treatment was applied for 30 seconds (group 1) and 60 seconds (group 3).

Adhesion to Er:YAG laser-prepared dentin after long-term water storage and thermocycling.

This in vitro study evaluated the microtensile bond strength of a resin composite to Er:YAG-prepared dentin after long-term storage and thermocycling. Eighty bovine incisors were selected and their roots removed. The crowns were ground to expose superficial dentin.

Effect of Er:YAG laser irradiation distance on superficial dentin morphology.

Purpose: To assess in vitro the effect of Er:YAG laser irradiation distance on dentin surface morphology, by SEM.

Methods: 60 sound human third molars were employed to obtain discs (approximately equal to 1mm thick), that were polished to standardize the smear layer. Discs were randomly assigned to six groups (n=10) and sequentially bisected.

Shear bond strength of resin-modified glass ionomer cements to Er:YAG laser-treated tooth structure.

This study evaluated the effect of Er:YAG laser irradiation of enamel and dentin on the shear bond strength of resin-modified glass ionomer cements (RMGIC). Twenty molars were selected and the roots removed. The crowns were bisected, embedded in polyester resin and ground to plane the enamel or expose the dentin.