Publications by authors named "Roberto S Pessoa"
This study evaluated the stress distribution in the dentoalveolar and palatal bone structures during maxillary expansion in a 17-year-old male patient with bilateral cleft lip and palate (BCLP) using expanders with dental (HYRAX) and skeletal anchorage (MARPE). For the generation of the specific finite element models, cone-beam computed tomography was used, and the DICOM files were exported to Mimics 3-Matic (Materialise) and Patran (MSC Software) software. Three specific three-dimensional models were generated: A) HYRAX: conventional four-banded hyrax screw (9 mm); B) MARPE-DS: 3 miniscrews (1.
View Article and Find Full Text PDFPurpose: The purpose of this study was to evaluate mouthguard shock absorption ability, strain, and stress generation during impact on dental implants placed in the anterior maxilla. The mouthguard material was also characterized.
Materials And Methods: Sixty experimental models were created and divided into six groups (n = 10): implant type, external hexagon (EH) and Morse taper (MT); without and with two mouthguards (MTG), EVA custom-fitted (Ct-MTG) and standard self-adapted (St-MTG).
Introduction: A ferrule on anterior endodontic-treated teeth has been evaluated using clinical trials, in vitro tests, and finite element analysis (FEA). The patient-specific FEA with a nonuniform ferrule and nonlinear contact biting load associated with clinical validation can be used to predict failure.
Methods: A patient was selected with both maxillary central incisors with different ferrule designs who received endodontic treatment and restoration using a fiber post, composite core, and computer aided design and computer aided manufacturing lithium disilicate ceramic crowns.
Purpose: To evaluate the influence of different implant numbers and connection types on the biomechanical behavior of mandibular full-arch implant-supported rehabilitation.
Materials And Methods: Computed tomography-based finite element models comprising a totally edentulous mandible and 3.8 × 13-mmdiameter implants, abutments, abutment screws, bar retaining screw, and bar were constructed.
Objectives: To evaluate clinical, radiographic, microbiologic, and biomechanical parameters related to bone remodeling around implants with external hexagon (EH) and Morse-taper (MT) connections.
Materials And Methods: Twelve totally edentulous patients received four custom-made implants in the interforaminal region of the mandible. Two of those implants had the same macroscopic design, but different prosthetic connections.
Background: It is not yet well understood to what extent different implant-abutment mismatch sizes and implant-abutment connection types may influence the peri-implant biomechanical environment of implants in different clinical situations.
Methods: Computed tomography-based finite element models comprising a maxillary central incisor socket and 4.5 × 13 mm outer-diameter implants with external and internal hex connection types were constructed.
Purpose: To evaluate the influence of different implant designs on the biomechanical environment of immediately placed implants.
Materials And Methods: Computed tomography (CT)-based finite element models comprising a maxillary central incisor socket and four commercially available internal-connection implants (SIN SW, 3i Certain, Nobel Replace, and ITI Standard) of comparable diameters and lengths were constructed. Biomechanical scenarios of immediate placement, immediate loading, and delayed loading protocols were simulated.
The objective of the present study was to assess the influence of various clinically relevant scenarios on the strain distribution in the biomechanical surrounding of five different dental implant macrogeometries. The biomechanical environment surrounding an implant, i.e.
View Article and Find Full Text PDFBackground: Chemical modification of implant surface is typically associated with surface topographic alterations that may affect early osseointegration. This study investigates the effects of controlled surface alterations in early osseointegration in an animal model.
Methods: Five implant surfaces were evaluated: 1) alumina-blasting, 2) biologic blasting, 3) plasma, 4) microblasted resorbable blasting media (microblasted RBM), and 5) alumina-blasting/acid-etched (AB/AE).
Purpose: To evaluate the influence of platform switching on the biomechanical environment of implants in different placement and loading protocols.
Materials And Methods: A computed tomography-based finite element model of a maxillary central incisor extraction socket was constructed containing a conical 13-mm external-hex implant with a 4.3-mm-diameter shoulder.
Context: The prediction of implant treatment is directly influenced by the quality of the remaining bone after tooth extraction.
Aims: The purpose of this experimental study was to, histologically and histometrically, evaluate the bone repair process in the central areas of extraction sockets filled with platelet-rich plasma.
Materials And Methods: Four young adult male Cebus apella monkeys were used.
Purpose: The purpose of the present study was to evaluate the biomechanical environment of immediately placed implants, before and after osseointegration, by comparing three different implant-abutment connection types.
Materials And Methods: A computer tomography-based finite element model of an upper central incisor extraction socket was constructed containing implants with either external hex, internal hex, or Morse-taper connection. Frictional contact elements were used in the bone, implant, abutment, and abutment screw interfaces in the immediately placed simulations.