Publications by authors named "Rossana P De Almeida"

Purpose: To evaluate the marginal and internal misfit of fixed partial denture zirconia frameworks developed from conventional impression and intraoral scanning, before and after being subjected to the thermal cycle of the covering ceramic.

Methods: A three-elements fixed partial denture was prepared, molded, and poured with polyurethane. Group CI (n= 7) was impressed by the conventional technique with polyvinyl siloxane material, and the plaster models scanned on the inEosX5 bench scanner.

View Article and Find Full Text PDF

Purpose: This study aimed to develop and evaluate a simple, non-destructive method for assessing the misfit and passivity of implant-retained prostheses frameworks.

Materials And Methods: To simulate the rehabilitation of a mandible posterior partially edentulous area using 3-unit screw-retained frameworks supported by two implants were fabricated and divided into the following five groups (n = 10 in each group): OP = one-piece framework cast in Co-Cr with the conventional method (control-group); Co-Cr frameworks sectioned and welded by laser (=LAS) or tungsten inert gas (=TIG); Co-Cr CAD-CAM = milled Co-Cr framework; Zir CAD-CAM = milled zirconia framework. The horizontal |X| and vertical |Y| misfits were measured using confocal laser scanning microscopy with one or both screws tightened.

View Article and Find Full Text PDF

Objective: This study evaluated the influence of carbamide peroxide, 10% and 16%, on the surface roughness and gloss of a pressable ceramic.

Materials And Methods: Carbamide peroxide (10% or 16%) was applied for 4 hours or 3 hours per day for 14 days, respectively, in pressable ceramic discs (14 mm × 2 mm). Specimens were stored in distilled water at 37°C.

View Article and Find Full Text PDF

Purpose: The objective of this study was to evaluate the marginal fit and the flexural resistance of nickel-chromium frameworks welded by different techniques, gas-torch, laser, and tungsten inert gas (TIG), compared with that of frameworks made via one-piece casting.

Methods: To evaluate the marginal fit, a master model was fabricated simulating four implants. Transfers and replicas were used to transfer the positions of the implants to the model, using a silicone matrix.

View Article and Find Full Text PDF

Tooth loss can result in loss of facial esthetics, in addition to its effect on mastication, swallowing, and speech. Adequate planning is required in order for the prosthetic treatment of the teeth and implants to be successful. Here, we present a clinical case demonstrating that improper positioning of an implant can make prosthetic rehabilitation unfeasible, necessitating new surgical and rehabilitation planning to achieve the desired esthetics.

View Article and Find Full Text PDF

Purpose: The purpose of this study was to evaluate the rotational freedom between implant and abutment counterpart of two abutments types over external hexagon implants submitted to mechanical cycling.

Materials And Methods: Ten implants with external hexagon (3.75 mm × 13 mm), five cast abutments, and five premachined abutments both with 4.

View Article and Find Full Text PDF

There is no consensus in literature regarding the best plan for prosthetic rehabilitation with partial multiple adjacent implants to minimize stress generated in the bone-implant interface. The aim of this study was to evaluate the biomechanical behavior of cemented fixed partial dentures, splinted and nonsplinted, on Morse taper implants and with different types of coating material (ceramic and resin), using photoelastic stress analysis. A photoelastic model of an interposed edentulous space, missing a second premolar and a first molar, and rehabilitated with 4 different types of cemented crowns and supported by 2 adjacent implants was used.

View Article and Find Full Text PDF

Purpose: The purpose of this study was to compare the tensile strength of commercially pure titanium dowels and cores cemented with zinc phosphate or resin cements.

Methods: Twenty-one extracted human canines were endodontically treated. The root preparations were accomplished using Largo reamers (10mm in depth and 1.

View Article and Find Full Text PDF