Paulo Santos-Filho - Academia.edu (original) (raw)

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Papers by Paulo Santos-Filho

General dentistry

With the advent of new adhesive technologies, fiber-reinforced composite fixed partial dentures (... more With the advent of new adhesive technologies, fiber-reinforced composite fixed partial dentures (FRC-FPDs) have become an inexpensive, esthetic and useful restorative option for patients missing a single tooth. This article describes a case involving an inlay-retained FRC-FPD with a prefabricated fiber-reinforced pontic substructure. In addition, a 6-year follow-up is presented. The FRC-FPD fully restored the single missing molar with simple and conservative intracoronal preparations in the proximal teeth and was deemed clinically acceptable after the evaluation period. The clinical procedures to build a FRC-FPD with a prefabricated fiber-reinforced pontic substructure typically are finished by the clinician in 1 or 2 visits without laboratory assistance, making it a viable alternative for patients who cannot afford implant-based treatment or a conventional metal-ceramic FPD.

... The dentin surface was scanned after enamel was removed by HCl-2% acid solution. The scanned ... more ... The dentin surface was scanned after enamel was removed by HCl-2% acid solution. The scanned surfaces were exported to Bio-CAD software where the pulp, PDL and a polymer-cylinder were created to simulate the experimental conditions. ...

Dental Traumatology, 2015

Objective: The purpose of this study was to investigate the influence of post and crown type and ... more Objective: The purpose of this study was to investigate the influence of post and crown type and ferrule presence on stress distribution, strain, fracture resistance and mode of failure of root filled teeth. Method: The investigation was conducted by using 3D finite element analysis (FEA) and in-vitro tests. 3D models of a maxillary central incisor were generated: WFe, without ferrule; Fe1, 1.0 mm of ferrule; and Fe2, 2.0 mm of ferrule; restored with glass fiber post (Gfp) or cast post-and-core (Cpc); and metal crowns (Mc) or alumina-reinforced ceramic crowns (Cc). Each FE model was subjected to 100 N oblique loads. The results were evaluated by von Mises criterion and Principal maximum stress. One hundred and twenty bovine incisors were selected and divided into 12 treatment groups (n=10). Treatment variations were the same as used in finite element analysis. The teeth were loaded at a 135-degree angle, and the root strain was measured. Specimens were subsequently loaded until frac...

Objective: To evaluate the micropush-out bond strength influence of self-cured and dual-cured lut... more Objective: To evaluate the micropush-out bond strength influence of self-cured and dual-cured luting systems and degree of conversion these systems. Method: Forty single-rooted bovine teeth were root filled and prepared to receive fiberglass post Exacto nº 3 [Angelus]. The luting systems (LS) tested were (n=10): All Bond 2 (AB)/C&B (CB) [Bisco], Fusion Duralink (FD)/Cement-Post (CP) [Angelus], SingleBond 2 (SB)/Rely X ARC (ARC) [3M Espe] and Rely X U100 (U100) [3M Espe]. Two slices for cervical, middle and apical third of root were obtained. The slices were tested with micropush-out test (MBS) at a speed of 0.5 mm min¯¹. Degree of conversion (DC) was determined by Fourier transform infrared spectroscopy (FT-IR) (n=3). The MBS and DC values were analyzed using ANOVA and Tukey’s test (p < 0.05). Result: The table shows MBS (MPa) and DC mean (%) and standard deviations for experimental groups. Luting System Third - MBS (MPa) DC (%) Cervical Middle Apical AB/CB 12.0±7.1Aab 5.6±2.9Ba ...

Brazilian Dental Journal, 2015

American journal of dentistry, 2015

To investigate the influence of a high elastic modulus material insert on the stress, shock absor... more To investigate the influence of a high elastic modulus material insert on the stress, shock absorption and displacement of mouthguards. Finite element models of a human maxillary central incisor with and without mouthguard were created based on cross-sectional CT-tomography. The mouthguard models had four designs: without insert, and middle, external, or palatal hard insert. The hard inserts had a relatively high elastic modulus when compared to the elastic modulus of ethylene vinyl acetate (EVA): 15 GPa versus 18 MPa. A non-linear dynamic impact analysis was performed in which a heavy rigid object hit the model at 1 m/s. Strain and stress (von Mises and critical modified von Mises) distributions and shock absorption during impact were calculated as well as the mouthguard displacement. The model without mouthguard had the highest stress values at the enamel and dentin structures in the tooth crown during the impact. It was concluded that the use of a mouthguard promoted lower stress...

Dental traumatology : official publication of International Association for Dental Traumatology, Jan 3, 2015

Custom-fitted mouthguards are devices used to decrease the likelihood of dental trauma. The aim o... more Custom-fitted mouthguards are devices used to decrease the likelihood of dental trauma. The aim of this study was to develop an experimental bovine dentoalveolar model with periodontal ligament to evaluate mouthguard shock absorption, and impact strain and stress behavior. A pendulum impact device was developed to perform the impact tests with two different impact materials (steel ball and baseball). Five bovine jaws were selected with standard age and dimensions. Six-mm mouthguards were made for the impact tests. The jaws were fixed in a pendulum device and impacts were performed from 90, 60, and 45° angles, with and without mouthguard. Strain gauges were attached at the palatal surface of the impacted tooth. The strain and shock absorption of the mouthguards was calculated and data were analyzed with 3-way anova and Tukey's test (α = 0.05). Two-dimensional finite element models were created based on the cross-section of the bovine dentoalveolar model used in the experiment. A ...

Brazilian Dental Journal, 2015

Objective: To evaluate the biomechanical behavior of endodontically treated anterior teeth by str... more Objective: To evaluate the biomechanical behavior of endodontically treated anterior teeth by strain measurement, finite element analysis (FEA), and fracture resistance by varying the presence of ferrule and length of different endodontic posts. Methods: Eighty bovine incisor roots were selected and divided into 2 groups (n = 40): with ferrule of 2.0 mm, with no ferrule. These groups were divided into 4 subgroups (n = 10) varying the endodontic posts: fiberglass posts and cast post-and-cores, in lengths of 12 and 7 mm. All roots were restored with metal crowns. Five specimens from each group were subjected to strain-gage measurement. The fracture resistance was measured in mechanical testing machine with application of tangential load at an angle of 135 ° with the long axis of the tooth. Data were submitted to factorial analysis of variance. The failure pattern was analyzed in accordance with the degree of damage to the tooth structure.Tridimensional models of each experimental grou...

Objective: The aim of this study was to quantify the influence of direct and indirect restorative... more Objective: The aim of this study was to quantify the influence of direct and indirect restorative techniques on stress distribution pattern of maxillary premolar by 3D finite element method. Method: One intact maxillary premolar was selected and the enamel/root boundaries were scanned using a contact-scanner (LPX-400, Roland, USA) in which 3D-stereolithography files were obtained. On the next step, the enamel and dentin were sequentially degraded with HCl-2% acid solution. The dentin/pulp boundaries were scanned. These files were exported to Bio-CAD software (Rhino3D). The volumes of each structure were obtained by NURBS surfaces association. In this software, the periodontal-ligament simulation was made. All volumes were exported to Finite Element software packages (NeiNastran and FEMAP). The meshes of each structure were created with tetrahedral nodes, according to mechanical properties obtained by literature review. A linear-static-isotropic model and boundary conditions were cre...

The journal of contemporary dental practice, 2007

The aim of this article is to describe a step-by-step protocol for emergency care of a patient wi... more The aim of this article is to describe a step-by-step protocol for emergency care of a patient with a dentoalveolar injury in the anterior region of the mouth as well as the fabrication of a mouthguard to prevent future trauma. Dental trauma is one of the most serious oral health problems in active children and adolescents. Care of traumatized patients requires immediate initial emergency treatment followed by integrated procedures to restore damaged oral structures along with a subsequent trauma prevention strategy. Dentoalveolar injuries in the anterior region of the mouth are often characterized by tooth avulsion and coronal fracture. They are managed using procedures such as dental splinting, endodontic therapy with its unique characteristics, and restorative techniques to re-establish function and esthetics as well as protective mouthguards. A 16-year-old male presented with avulsion of his maxillary central incisors as a result of a direct, unintentional impact with an opponen...

Acta odontológica latinoamericana : AOL, 2012

This study evaluated the effect of adhesive application only to enamel on the marginal microleaka... more This study evaluated the effect of adhesive application only to enamel on the marginal microleakage of composite resin restorations performed with different adhesive systems. Standardized cylinder-shaped cavities were prepared on the buccal surface of eighty bovine incisors. Two etch-and-rinse (Adper Scotchbond Multi-purpose [3M ESPE, St. Paul, MN USA] and Adper Single Bond 2 [3M ESPE]) and two self-etching (Clearfil SE Bond [Kuraray, Osaka, Japan] and Adper Prompt [3M ESPE]) adhesive systems were evaluated. The adhesives were applied only to enamel or to both dentin and enamel. After adhesive light-activation, the cavities were restored with composite resin. The samples were coated with two layers of nail polish, except an area of 1-mm wide around of the restoration, and immersed in a methylene blue solution. Afterwards, the specimens were ground in order to obtain powder which was immersed in absolute alcohol. The solutions were centrifuged and the supernatant was analyzed using a...

Brazilian oral research

The aim of this study was to evaluate the effect of parallel and tapered threaded post placement ... more The aim of this study was to evaluate the effect of parallel and tapered threaded post placement on the strain and stress distribution of endodontically treated teeth. Fifteen bovine incisors were sectioned 15 mm from their apices, endodontically treated, and divided into three groups (n=5) according to three different threaded posts: parallel threaded post (Radix-Anker, RA); tapered threaded post (Euro-Post, EP) and tapered threaded post (Reforpost II, RII). A strain-gauge was fixed on the proximal surface perpendicular to the long root axis, 2 mm from the cervical limit. Strain generated during post placement was recorded and compared using one-way ANOVA and Tukey's test (α=.05). A scanning electron microscope was used to examine the longitudinal root sections. Stress was evaluated for each group in a two-dimensional finite element analysis. The models were meshed with tetrahedron elements and loaded with 2 N at an angle of 135° to the lingual face. The equivalent Von Mises st...