Effect of the Combination of Restorative Material and the Etching Protocol in Enamel Microleakage in Class II Cavities after Thermocycling.

This study is aimed at evaluating the marginal microleakage of bulk-fill class II restorations after thermocycling. Thirty-two human third molars received class II cavities prepared on mesial and distal faces. The cavities were bonded according to the adhesive protocol (total or self-etching).

Resin composite adhesion to dentin using different curing lights and adhesive systems applied under electric current.

Objectives: To evaluate the effect of electric current application on the resin composite-tooth bond strength and hybrid layer of three adhesive systems light-cured by two light-curing units (LCUs).

Materials And Methods: Human molar teeth were distributed into 12 groups (n=6). Three adhesive systems were used: two-step etch-and-rinse (SB2; Adper Single Bond 2, 3M ESPE); two-step self-etch (CSE; Clearfil SE Bond, Kuraray); and one-step self-etch (SBU; Single Bond Universal, 3M ESPE) applied with (50μA) and without (control; conventional application) electric current, and light-cured with different LCUs.

Mouthguard Use Effect on the Biomechanical Response of an Ankylosed Maxillary Central Incisor during a Traumatic Impact: A 3-Dimensional Finite Element Analysis.

(1) Background: Trauma is a very common experience in contact sports; however, there is an absence of data regarding the effect of athletes wearing mouthguards (MG) associated with ankylosed maxillary central incisor during a traumatic impact. (2) Methods: To evaluate the stress distribution in the bone and teeth in this situation, models of maxillary central incisor were created containing cortical bone, trabecular bone, soft tissue, root dentin, enamel, periodontal ligament, and antagonist teeth were modeled. One model received a MG with 4-mm thickness.

Biomechanical evaluation of anterior implants associated with titanium and zirconia abutments and monotype zirconia implants.

Purpose: The present in silico study evaluated the behavior of titanium dental implants associated with abutments in zirconia and monotype zirconia implant using finite element analysis (FEA).

Methods: A partial image of the anterior region of the maxilla was obtained by computed tomography. Three models of finite element were made using 3D modeling software (SolidWorks): Ti-Ti (control): implant morse cone (3.

Effect of Implant Platform Connection and Abutment Material on Removal Torque and Implant Hexagon Plastic Deformation.

Objectives:  The aim of this study was to evaluate the plastic deformation of the hexagonal connection, and the removal torque of the implant-abutment joint of two dental implants combined with internal or external hexagonal connection implants after mechanical cycling.

Materials And Methods:  Twenty-four dental implants were used in the study. Half of the implants had internal hexagonal connections (IH; Titamax II Plus) and the other half had external hexagonal connections (EH; Titamax Ti Ex).

Influence of polishing systems on roughness and color change of two dental ceramics.

Purpose: To evaluate the polishing effect on roughness and color change of pressed and layering ceramics after immersion in coffee solution.

Materials And Methods: 88 ceramic discs (1.0 mm × 10.

Effect of polymerization method and fabrication method on occlusal vertical dimension and occlusal contacts of complete-arch prosthesis.

Purpose: This study evaluated the dimensional stability of a complete-arch prosthesis processed by conventional method in water bath or microwave energy and polymerized by two different curing cycles.

Materials And Methods: Forty maxillary complete-arch prostheses were randomly divided into four groups (n = 10): MW1 - acrylic resin cured by one microwave cycle; MW2 - acrylic resin cured by two microwave cycles: WB1 - conventional acrylic resin polymerized using one curing cycle in a water bath; WB2 - conventional acrylic resin polymerized using two curing cycles in a water bath. For evaluation of dimensional stability, occlusal vertical dimension (OVD) and area of contact points were measured in two different measurement times: before and after the polymerization method.

Influence of plasma-based dry etching on the bond strength of Y-TZP ceramic.

The aim of this study was to evaluate the bond strength between an yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic and a luting agent when submitted to plasma etching surface treatment before and after thermocycling (TC) with 3000 cycles of 5°C-55°C. The null hypothesis was that the surface treatments and thermocycling would not influence the bond strength. A total of 160 Y-TZP ceramic blocks in 2 sizes (10 size 1 and 10 size 2 blocks in each group) were distributed into 8 groups: group C (control), no surface treatment; group C-TC, TC without prior surface treatment; group SAO, sandblasting with aluminum oxide (Al2O3); group SAO-TC, sandblasting with Al2O3 followed by TC; group SAOS, sandblasting with silica-coated Al2O3; group SAOS-TC, sandblasting with silica-coated Al2O3 followed by TC; group PE, plasma etching; and group PE-TC, plasma etching followed by TC.

Wear at the Implant-Abutment Interface of Zirconia Abutments Manufactured by Three CAD/CAM Systems.

Purpose: To evaluate the changes in the external-hexagon surface of the titanium (Ti) implant before and after mechanical cycling, when coupled with zirconia (Zr) abutments (A) manufactured by three computer-aided design/computer-aided manufacturing (CAD/CAM) systems (Neodent Digital, Zirkonzahn, and AmannGirrbach) and the ZrTi abutment manufactured by Neodent.

Materials And Methods: Four groups were formed (n = 6): titanium implant with Zr AmannGirrbach abutment (AZrAG), with Zr Zirkonzahn abutment (AZrZ), with Zr Neodent abutment (AZrN), and with Zr abutment with infrastructure in Ti Neodent (AZrTiN). Standardized abutments were made from three identical abutments milled in wax.

Three-dimensional finite element analysis of occlusal splint and implant connection on stress distribution in implant-supported fixed dental prosthesis and peri-implantal bone.

The aim of this study was to investigate the influence of occlusal splint therapy on the stress distribution of implant-supported fixed dental prosthesis (FDP) and peri-implantal bone structures using three-dimensional (3D) finite element analysis (FEA). The system consisted of two implants (positioned on region of second premolar and second molar) as retainers of fixed porcelain-fused-to-metal 3-unit FDP (first molar as pontic element). Two implant connections systems (external and internal hexagon) were tested.

Comparative photoelastic study of dental and skeletal anchorages in the canine retraction.

Objective: To compare dental and skeletal anchorages in mandibular canine retraction by means of a stress distribution analysis.

Methods: A photoelastic model was produced from second molar to canine, without the first premolar, and mandibular canine retraction was simulated by a rubber band tied to two types of anchorage: dental anchorage, in the first molar attached to adjacent teeth, and skeletal anchorage with a hook simulating the mini-implant. The forces were applied 10 times and observed in a circular polariscope.

Evaluation of castable and premachined metal base abutment/implant interfaces before and after cyclical load.

Purpose: The purpose of this study was to compare the vertical fit of the castable abutment/implant and premachined base metal abutment/implant interface, before and after cyclic loading.

Materials And Methods: Ten UCLA abutments were distributed in 2 groups: castable and premachined with a cobalt-chromium metal base. The abutments were cast in cobalt-chromium alloy and were screwed onto implants (3.

Influence of diamondlike carbon-coated screws on the implant-abutment interface.

Purpose: To evaluate the implant-abutment interface area and the abutment screw loosening value when diamondlike carbon (DLC)-coated or titanium screws were used before and after cyclic loading.

Materials And Methods: Thirty-six implants were divided into four groups according to the type of connection (external hexagon [EH] or internal hexagon [IH]) and the type of abutment screw (with [EHD/IHD] or without [EHT/IHT] DLC coating). The implants were placed in epoxy resin-glass fiber composite, and crowns cast in a metal alloy were screwed to the implants.

Influence of loading and use of occlusal splint in implant-supported fixed prostheses.

The aim of the study was to assess the tensions generated in the long axis of the implants and the interimplants in the cervical, middle, and apical regions when subjected to different loads with or without interposition of the flat occlusal plane splint. A photoelastic model was made with 2 external hexagon implants located in the space corresponding to the second premolar and molar inferiors. A screw-retained metal superstructure was installed on the implants with a torque of 20 N·cm, and the set (photoelastic model with superstructure) were positioned in the circular polariscope in the dark-field configuration to observe the distribution of isochromatic fringes around the implants and interimplant areas.

Influence of anatomic reference on the buccal contour of prosthetic crowns.

During clinical practice, when performing prosthetic rehabilitation with single crowns, improper reproduction of the dental contour by the dental laboratory is a common occurrence. Therefore, the present study evaluated the fidelity of the reproduction of the buccal contour in an upper left canine performed by three Dental Prosthesis Technicians (DPT) using the indirect laminate veneer technique. First, the DPTs confected the veneers based on a model obtained from the upper arch of a dental dummy, containing a replica of an upper left canine with a prosthetic preparation for a laminate veneer.

Concurrence between interpupillary line and tangent to the incisal edge of the upper central incisor teeth.

Objective: Dento-facial harmony is essential to obtain adequate esthetics and a successful treatment. Therefore, the aim of the present study was to analyze the existence of polar symmetry, obtained by two parallel lines, one along the pupils and another along the incisal edge of the upper central incisor teeth of 102 dental students distributed across five Brazilian dental schools.

Materials And Methods: One hundred and two students with no missing teeth, who had never been subjected to any kind of dental treatment, not even orthodontic treatment, were selected and photographed using a dental eye II camera (Yashica-Kyocera Optics Inc.