Crisnicaw Veríssimo
Federal University of Uberlandia
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Featured researches published by Crisnicaw Veríssimo.
Journal of Endodontics | 2014
Paulo César Freitas Santos-Filho; Crisnicaw Veríssimo; Paulo Vinícius Soares; Rebeca Carniello Saltarelo; Carlos José Soares; Luis Roberto Marcondes Martins
INTRODUCTION The aim of this study was to evaluate the influence of post system, length, and ferrule on biomechanical behavior of endodontically treated anterior teeth. METHODS The investigation was conducted by using laboratory tests and 3-dimensional finite element analysis. Eighty bovine incisors were selected and divided into 8 treatment groups (n = 10) with absence of ferrule and 2.0 mm of ferrule, restored with glass fiber post or cast post and core, and 12.0 and 7.0 mm of post length. The specimens were loaded at 135° angle, and the strain was measured by using strain gauge method. Specimens were subsequently loaded until fracture. Strain and fracture resistance results were analyzed by 3-way analysis of variance and Tukey honestly significant difference tests (α = 0.05). Three-dimensional models of a maxillary central incisor were generated with the same treatment variations used in laboratory tests. Each model was subjected to 100 N oblique loads. Results were evaluated by von Mises criterion. RESULTS Ferrule was a determining factor in the strain, fracture resistance, and fracture pattern. In the absence of ferrule, the use of fiberglass posts represents a conservative choice from the standpoint of the fracture patterns observed. The length of 7 mm for cast post and cores produced high rates of root fractures. Finite element analysis showed that glass fiber post showed homogeneous stress distribution, whereas cast post showed stress concentration into root canal. CONCLUSIONS Post length influenced only the cast post strain and stress distribution. The ferrule groups always showed more satisfactory stress distribution and fracture resistance.
Journal of Endodontics | 2014
Paulo César Freitas Santos-Filho; Crisnicaw Veríssimo; Luís Henrique Araújo Raposo; MecEng Pedro Yoshito Noritomi; Luis Roberto Marcondes Martins
INTRODUCTION The aim of this study was to evaluate the influence of a ferrule, post system, and length on the stress distribution of weakened root-filled teeth. METHODS The investigation was conducted by using 3-dimensional (3D) finite element analysis. A sound tooth and 8 3D models of a weakened root-filled central incisor were generated using computer-aided design/computer-aided manufacturing software. The models were created without a ferrule and with a 2.0-mm ferrule, restored with a relined glass fiber post or a cast post and core (Cpc), and 12.0- and 7.0-mm post lengths. Each 3D model was imported using ∗.STEP files to the finite element software for mesh generation. The models were subjected to 100-N oblique loading at the palatal surface, and the results were evaluated by von Mises criterion and maximum principal stress distribution. RESULTS Finite element analysis showed that the Cpc models showed elevated stress levels in the root canal regardless of the presence of a ferrule. Relined glass fiber post models showed homogeneous stress distribution to the dentin external surface similar to the sound tooth model. Without a ferrule, Cpc with a 7- or 12-mm length promoted high levels of tensile stress inside the root canal. CONCLUSIONS Ferrule presence promoted more satisfactory stress distribution to the roots. Post length influenced the stress distribution only for the models restored with a cast post and core. High levels of tensile stress inside the root canals were verified with a cast post and core, which should be avoided to rehabilitate weakened roots, mainly in the absence of a ferrule.
Dental Traumatology | 2016
Crisnicaw Veríssimo; Paulo Victor Moura Costa; Paulo César Freitas Santos-Filho; Daranee Tantbirojn; Antheunis Versluis; Carlos José Soares
BACKGROUND/AIM The aim of this study was to evaluate the tooth stresses and strains, shock absorption, and displacement during impact of custom-fitted mouthguards with different thicknesses. METHODS Six bar-shaped specimens of the EVA were made and subjected to tensile test for elastic modulus assessment. Two-dimensional plane-strain models of a human maxillary central incisor, periodontal ligament, bone support, soft tissue, and mouthguard (MTG) were created. The mouthguards were modeled in five different thicknesses (2, 3, 4, 5, and 6 mm). One model was created without mouthguard. A nonlinear dynamic impact analysis was performed in which a rigid object hit the model at 1 m s(-1). Strain and stress (von Mises and Critical modified von Mises) distributions were evaluated, and the displacement of the mouthguard with respect to the tooth was calculated. RESULTS The mean [SD] for the EVA elastic modulus was 18.075 [0.457] MPa. The model without mouthguard showed the highest stress values at the enamel and dentin structures in the tooth crown during the impact. For the MTG models, the location of the stress concentrations changed to the root, regardless of the MTG thickness, but maximum stresses in the enamel and dentin were lower compared with the model without MTG. Increasing the mouthguard thickness did not notably decrease the stress-strain values. CONCLUSION It was concluded that the use of a mouthguard promoted lower stresses and strains in teeth during an impact with a rigid object. There was no substantial difference in peak stresses and strains and in shock absorption among the different mouthguard thicknesses.
Brazilian Oral Research | 2013
Paulo César Freitas Santos Filho; Paulo Vinícius Soares; Bruno Rodrigues Reis; Crisnicaw Veríssimo; Carlos José Soares
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 Tukeys 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 stress was calculated. The one-way ANOVA showed significant difference among the groups. The RA group (150.0±12.2 A) produced higher external strain than the RII (80.0±12.2 B) and the EP (70.0±6.1 B) groups. The inner strain was approximately five times greater than the external dentin strain. High stress concentrations in each thread of the posts were observed. Scanning electron micrographs showed cracks that started in the threads of the posts. The threaded post placement induced root strain mainly on the parallel side post. Root strain and stress concentration on the post threads tended to create cracks in the inner root canal dentin.
Brazilian Dental Journal | 2015
Natércia Rezende da Silva; Grazielle Crystine Rodrigues Aguiar; Monise de Paula Rodrigues; A.A. Bicalho; Priscilla Barbosa Ferreira Soares; Crisnicaw Veríssimo; Carlos José Soares
The aim of this study was to evaluate the effect of porosity of self-adhesive resin on the stress distribution, post retention and failure mode of fiber post cemented to human root dentin. Ten human central upper incisors with circular root canal were selected. They were sectioned with 15 mm and were endodontically filled. The roots were scanned using micro-CT after post space preparation for root filling remaining evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were scanned for resin cement bubbles volume measurements and submitted to a push-out test (PBS). Three operators using stereomicroscopy and confocal laser microscopy classified the failure mode. Stress distributions during the push-out test were analyzed using 3D finite element analysis. PBS values (MPa) were submitted to one-way ANOVA and Tukeys post hoc tests and the failure modes using the Kappa coefficient to assess inter-operator agreement. Chi-square test was used to determine significant differences between the methods ( = 0.05). Push-out bond strength was significantly affected by the bubbles presence in all root depth (p<0.05). The stress concentration was higher when the bubbles were present. Adhesive dentin/resin cement interface failure was the most frequent type of failure. Confocal microscopy was better than stereomicroscopy for failure analysis. Bubbles generated during resin cement insertion into the root canal negatively affect the stress distribution and the bond strength. The use of confocal microscopy is recommended for failure analysis.
Archive | 2012
Carlos José Soares; Antheunis Versluis; Andréa Dolores Correia Miranda Valdivia; A.A. Bicalho; Crisnicaw Veríssimo; Bruno de Castro Ferreira Barreto; Marina Guimarães Roscoe
The primary function of the human dentition is preparation and processing of food through a biomechanical process of biting and chewing. This process is based on the transfer of masticatory forces, mediated through the teeth (Versluis & Tantbirojn, 2011). The intraoral environment is a complex biomechanical system. Because of this complexity and limited access, most biomechanical research of the oral environment such as restorative, prosthetic, root canal, orthodontic and implant procedures has been performed in vitro (Assuncao et al., 2009). In the in vitro biomechanical analysis of tooth structures and restorative materials, destructive mechanical tests for determination of fracture resistance and mechanical properties are important means of analyzing tooth behavior. These tests, however, are limited with regard to obtaining information about the internal behavior of the structures studied. Furthermore, biomechanics are not only of interest at the limits of fracture or failure, but biomechanics are also important during normal function, for understanding property-structure relationships, and for tissue response to stress and strain. For a more precise interrogation of oral biomechanical systems, analysis by means of computational techniques is desirable.
Dental Traumatology | 2017
Crisnicaw Veríssimo; A.A. Bicalho; Priscilla Barbosa Ferreira Soares; Daranee Tantbirojn; Antheunis Versluis; Carlos José Soares
BACKGROUND/AIM Custom-fitted mouthguards are devices used to prevent dental injuries. The aim of this study was to verify the influence of the antagonist contact on the stresses and strains of the anterior teeth, shock absorption and displacement of EVA custom-fitted mouthguards during a horizontal impact. MATERIALS AND METHODS Finite element models of human maxillary central incisors with and without a mouthguard for different occlusion conditions (with and without antagonist contact) were created based on tomography. A nonlinear dynamic impact analysis using the single-step Houbolt method was performed in which a rigid object hit the model at 1 m s-1 . Strain and stress were evaluated by means of Von Mises and Critical modified Von Mises criterion and shock absorption during impact were calculated as well as the mouthguard displacement. RESULTS The model without mouthguard and without antagonist contact showed the highest stress and strain values at the enamel and dentin in the tooth crown on impact compared to the model without mouthguard and with antagonist contact. Mouthguard presence reduced the stress and strain values regardless of the occlusion condition. The mouthguard displacement decreased with the mandibular antagonist contact. CONCLUSIONS Mouthguards are efficient at decreasing the stress and strain values on the tooth in front of an impact reaching more than 90% of shock absorption. A mouthguard with balanced occlusion and maximum number of contacts with mandibular anterior teeth should be considered because it reduces mouthguard displacement.
Journal of Endodontics | 2017
Monise de Paula Rodrigues; Priscilla Barbosa Ferreira Soares; Andréa Dollores Correia Miranda Valdivia; Roberto Sales Pessoa; Crisnicaw Veríssimo; Antheunis Versluis; Carlos José Soares
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. Strain gauges were attached to the buccal surfaces of both teeth to record ceramic strain during bite force recording for FEA validation. Cone‐beam computed tomographic imaging was performed, and the Digital Imaging and Communication in Medicine files were exported to Mimics, 3‐Matic (Materialise, Leuven, Belgium) and Patran (MSC Software, Santa Ana, CA) software to create a patient‐specific FEA model. Bite load was applied using contact load applied by antagonist teeth (155 N). Mechanical properties were obtained from the literature. Modified von Mises equivalent stress was used for stress evaluation. Results Stresses on the dentin and fiber post on the left incisor, which had a nonuniform ferrule, were higher compared with the right incisor. The strain values recorded for the right central incisor (strain gauge =79.9 ± 3.8 &mgr;S and FEA = 69.5 &mgr;S) and the left central incisor (strain gauge = 83.5 ± 5.3 &mgr;S and FEA = 73.9 &mgr;S) validate the FEA analysis. Conclusions FEA was validated with in vivo strain values measured at the buccal crown surfaces, supporting that the stress levels were realistic for investigation of the clinical performance of fiber posts. Maintaining a uniform ferrule was more favorable than a localized higher ferrule. HighlightsThis study created the protocol for combining the patient‐specific finite element model with clinical validation. This method proved to be an important tool for the evaluation of endodontic‐treated teeth restored using a fiber post.Simulating loading using the antagonists resulted in a realistic stress level considering the clinical success of the fiber post.The strain values recorded on the ceramic surface for both central incisors validated the finite element analysis (FEA).This patient‐specific FEA supported that the stress levels were realistic for the investigation of the clinical performance of fiber posts.Clinically, the contribution was that maintaining a uniform ferrule was more favorable than a localized higher ferrule.
Brazilian Oral Research | 2015
Carolina Guimarães Castro; Karla Zancopé; Crisnicaw Veríssimo; Carlos José Soares; Flávio Domingues das Neves
The aim of this study was to evaluate the amount of deformation from compression caused by different diameters of Morse taper implants and the residual deformation after load removal. Thirty Morse taper implants lacking external threads were divided into 3 groups (n = 10) according to their diameter as follows: 3.5 mm, 4.0 mm and 5.0 mm. Two-piece abutments were fixed into the implants, and the samples were subjected to compressive axial loading up to 1500 N of force. During the test, one strain gauge remained fixed to the cervical portion of each implant to measure the strain variation. The strain values were recorded at two different time points: at the maximum load (1500 N) and 60 seconds after load removal. To calculate the strain at the implant/abutment interface, a mathematical formula was applied. Data were analyzed using a one-way Anova and Tukeys test (α = 0.05). The 5.0 mm diameter implant showed a significantly lower strain (650.5 μS ± 170.0) than the 4.0 mm group (1170.2 μS ± 374.7) and the 3.5 mm group (1388.1 μS ± 326.6) (p < 0.001), regardless of the load presence. The strain values decreased by approximately 50% after removal of the load, regardless of the implant diameter. The 5.0 mm implant showed a significantly lower strain at the implant/abutment interface (943.4 μS ± 504.5) than the 4.0 mm group (1057.4 μS ± 681.3) and the 3.5 mm group (1159.6 μS ± 425.9) (p < 0.001). According to the results of this study, the diameter influenced the strain around the internal and external walls of the cervical region of Morse taper implants; all diameters demonstrated clinically acceptable values of strain.
Brazilian Dental Journal | 2013
Gabriela Campos Mesquita; Crisnicaw Veríssimo; Luís Henrique Araújo Raposo; Paulo César Freitas Santos-Filho; Adérito Soares da Mota; Carlos José Soares
The cure time of endodontic sealers may influence the bond strength of fiber posts to root dentin. Forty teeth were selected and endodontically filled using calcium hydroxide cement and then divided into 2 groups according to the time elapsed between endodontic filling and post luting (n = 20): Immediately - glass fiber post luting immediately after endodontic filling; and Delayed - post luting performed 7 days after endodontic filling. The roots were also subdivided according to resin cement used for post luting (RelyX ARC and RelyX Unicem). The specimens were stored at 37°C for 24 h and sectioned in six 1-mm-thick slices from cervical, middle and apical thirds. The slice specimens were submitted to a push-out test at a crosshead speed of 0.5 mm/min, and the bond strength values obtained (MPa) were submitted to two-way ANOVA in a split-plot arrangement and Tukeys test (α=0.05). For both RelyX ARC and Unicem, the bond strength was significantly higher when the posts were cemented 7 days after the endodontic treatment. RelyX Unicem showed significantly higher bond strength values than RelyX ARC for both cementation periods. It was concluded that post luting should be made after the complete setting of the root canal sealer. Self-adhesive resin cement should be preferred for fiber post luting.