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Papers by Gustavo Frainer Barbosa
American journal of dentistry, 2018
To evaluate the color change caused by cigarette smoke in both microhybrid and nanohybrid resin c... more To evaluate the color change caused by cigarette smoke in both microhybrid and nanohybrid resin composites of three different manufacturers (Z100, Z350, Charisma, and Opallis). Samples of microhybrid (n= 40) and nanohybrid (n= 40) resin composites (A2) were prepared for each resin brand, totaling 240 samples. The samples were divided into subgroups: Control: control group without exposure; C5: five cigarettes, 25 minutes/ exposure; C10: 10 cigarettes, 50 minutes/ exposure; C20: 20 cigarettes, 100 minutes/ exposure. The samples were then photographed and color change was measured by a computerized image analysis. L*a*b* values were obtained and color change was calculated. The Kolmogorov-Smirnov test was used to examine data normality; color change associated with an individual brand and the number of smoked cigarettes was analyzed with differentiation across the groups by the Tukey test (P≤ 0.05). The student t-test (P≤ 0.05) was used for the differentiation of inorganic fillers. Th...
Full Dentistry in Science
The Journal of oral implantology, Jan 14, 2017
Presenting patients with the opportunity to restore their smiles using dental implants, which is ... more Presenting patients with the opportunity to restore their smiles using dental implants, which is a reliable and widely accepted technique, is highly recommended. Therefore, a correct clinical judgment and a, consequently, dental implant treatment planning is a central component of a good practice of implant dentistry. Moreover, to the oral clinician be able to make better decisions and reach a more accurate clinical judgment, it is necessary continuing professional development being, this development, an essential professional activity for dentists that intend planning implant treatments. Thus, considering that a correct "clinical judgment is a central component of the practice of implant dentistry", this paper intends to discuss some issues related to the impact that professional formation might have on patient-centered outcomes. By describing three examples of inaccurate treatment decisions through the analysis of radiographic images (two panoramic radiographies and 1 pe...
Implantnews, 2007
Base de dados : LILACS. Pesquisa : 518123 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 518123 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. experimental, Documentos relacionados. Id: 518123. ...
The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of... more The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality.
Implantnews, Dec 30, 2008
Clinical Oral Implants Research
Background: The bone quality classification proposed by Lekholm and Zarb in 1985 describes four t... more Background: The bone quality classification proposed by Lekholm and Zarb in 1985 describes four types of bone depending on proportion of cortical and cancellous bone in radiographic examinations. It is accepted that the type IV bone (less quantity of cortical bone) is more susceptible to implant failures since it is related with lower primary stability. In other hand, type I and type II bones are known to present better primary stability and consequently higher survival rates. Retrospective data of conventional implants placed in the mandible showed an inverse correlation between the proportion of cortical bone and marginal bone loss. However, the effect of cortical bone proportion on marginal bone loss of single short implants placed in the posterior region of mandible and maxilla remains unclear.
This study tested two hypotheses. The first null hypothesis affirms that there is no statistical ... more This study tested two hypotheses. The first null hypothesis affirms that there is no statistical difference when composite resin is submitted to knoop or vickers microhardness using different testing protocols. The second hypothesis tested the possible influence of elastic modulus of composite resin in microhardness tests. Two nanohybrid composites were used with different viscosity behavior (Grandio and Grandio Flow). Samples (n=540) were made with 4 mm diameter and 2 mm high using a PTFE mould, stored for 24h at 37°C protected from light and randomly divided into 36 groups according to the resin viscosity (medium and low), microhardness methodology (vickers or knoop), load (50, 100 or 500g) and time (15, 30 or 45s). Two readings were made at the light exposed surface of each sample with Shimadzu HMV tester accomplishing 1.080 indentations. The vickers and knoop results were submitted to a three-way ANOVA with fixed factors the composite viscosity, load and time, and the post-hoc Tukey multiple comparison test at α=0.05. Significant differences were recorded (p<0.001) between the microhradness methodologies with two viscosities rejecting both hypotheses rejecting both null hypotheses. Among the vickers tested samples, the average recorded ranged from 164.94 (50g for 45s) to 210.33 (100g for 45s) for the medium viscosity composite and from 31.2 (100g for 30s) to 88 (500g for 45s) for a low viscosity resin. Knoop microhardness results ranged from 128.92 (500g for 45s) to 184.26 (100g for 15s) for medium viscosity composite and from 23.6 (100g for 15s) to 73.4 (500g for 30s) for flowable compositive. In a controlled in vitro experiment, the microhardness formulas mislead researchers to associate an improvement of diagonal measurements to higher load with a linear and proportional behavior. It is not recommended to clinicians compare both vickers and knoop microhardness results of composite materials without similar protocols applied in the research.
Background: Short dental implants have been considered as an alternative treatment to advanced bo... more Background: Short dental implants have been considered as an alternative treatment to advanced bone augmentation surgery in the posterior region of maxilla and mandible. Nevertheless, most previous studies clustered the clinical outcomes of short implants supporting different types of reconstructions, from single crowns to fixed partial dentures and overdentures. Also, they usually assessed survival rates of short implants based on heterogeneous data from both retrospective and prospective studies. Therefore, there is still controversy on the prognosis and biomechanical risk factors for the rehabilitation of the posterior region of maxilla and mandible with single crowns supported by short implants.
Stomatologija / issued by public institution "Odontologijos studija" ... [et al.], 2008
The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of... more The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality. The aim of this study was the processing of tomographic images in order to develop an advanced three-dimensional reconstruction of the anatomy of a molar tooth and the integration of the resulting solid with commercially available CAD/CAE software. Computed tomographic images were obtained from 0.5 mm thick slices of mandibular molar and transferred to commercial cad software. Once the point cloud data have been generated, the work on these points started to get to the solid model of the tooth with Pro/Engineer software. The obtained tooth model showed very accurate shape and dimensions, as it was obtained from rea...
Stomatologija, 2008
The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of... more The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality.
Revista Odonto Ciência, 2016
Background: Search for materials that may either replace titanium dental implants or constitute a... more Background: Search for materials that may either replace titanium dental implants or constitute an alternative as a new dental implant material has been widely studied. As well, the search for optimum biocompatible metal surfaces remains crucial. So, the aim of this work is to develop an oxidized surface layer on tantalum using plasma electrolytic oxidation (PEO) similar to those existing on oral implants been marketed today.
American journal of dentistry, 2018
To evaluate the color change caused by cigarette smoke in both microhybrid and nanohybrid resin c... more To evaluate the color change caused by cigarette smoke in both microhybrid and nanohybrid resin composites of three different manufacturers (Z100, Z350, Charisma, and Opallis). Samples of microhybrid (n= 40) and nanohybrid (n= 40) resin composites (A2) were prepared for each resin brand, totaling 240 samples. The samples were divided into subgroups: Control: control group without exposure; C5: five cigarettes, 25 minutes/ exposure; C10: 10 cigarettes, 50 minutes/ exposure; C20: 20 cigarettes, 100 minutes/ exposure. The samples were then photographed and color change was measured by a computerized image analysis. L*a*b* values were obtained and color change was calculated. The Kolmogorov-Smirnov test was used to examine data normality; color change associated with an individual brand and the number of smoked cigarettes was analyzed with differentiation across the groups by the Tukey test (P≤ 0.05). The student t-test (P≤ 0.05) was used for the differentiation of inorganic fillers. Th...
Full Dentistry in Science
The Journal of oral implantology, Jan 14, 2017
Presenting patients with the opportunity to restore their smiles using dental implants, which is ... more Presenting patients with the opportunity to restore their smiles using dental implants, which is a reliable and widely accepted technique, is highly recommended. Therefore, a correct clinical judgment and a, consequently, dental implant treatment planning is a central component of a good practice of implant dentistry. Moreover, to the oral clinician be able to make better decisions and reach a more accurate clinical judgment, it is necessary continuing professional development being, this development, an essential professional activity for dentists that intend planning implant treatments. Thus, considering that a correct "clinical judgment is a central component of the practice of implant dentistry", this paper intends to discuss some issues related to the impact that professional formation might have on patient-centered outcomes. By describing three examples of inaccurate treatment decisions through the analysis of radiographic images (two panoramic radiographies and 1 pe...
Implantnews, 2007
Base de dados : LILACS. Pesquisa : 518123 [Identificador único]. Referências encontradas : 1 [ref... more Base de dados : LILACS. Pesquisa : 518123 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. experimental, Documentos relacionados. Id: 518123. ...
The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of... more The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality.
Implantnews, Dec 30, 2008
Clinical Oral Implants Research
Background: The bone quality classification proposed by Lekholm and Zarb in 1985 describes four t... more Background: The bone quality classification proposed by Lekholm and Zarb in 1985 describes four types of bone depending on proportion of cortical and cancellous bone in radiographic examinations. It is accepted that the type IV bone (less quantity of cortical bone) is more susceptible to implant failures since it is related with lower primary stability. In other hand, type I and type II bones are known to present better primary stability and consequently higher survival rates. Retrospective data of conventional implants placed in the mandible showed an inverse correlation between the proportion of cortical bone and marginal bone loss. However, the effect of cortical bone proportion on marginal bone loss of single short implants placed in the posterior region of mandible and maxilla remains unclear.
This study tested two hypotheses. The first null hypothesis affirms that there is no statistical ... more This study tested two hypotheses. The first null hypothesis affirms that there is no statistical difference when composite resin is submitted to knoop or vickers microhardness using different testing protocols. The second hypothesis tested the possible influence of elastic modulus of composite resin in microhardness tests. Two nanohybrid composites were used with different viscosity behavior (Grandio and Grandio Flow). Samples (n=540) were made with 4 mm diameter and 2 mm high using a PTFE mould, stored for 24h at 37°C protected from light and randomly divided into 36 groups according to the resin viscosity (medium and low), microhardness methodology (vickers or knoop), load (50, 100 or 500g) and time (15, 30 or 45s). Two readings were made at the light exposed surface of each sample with Shimadzu HMV tester accomplishing 1.080 indentations. The vickers and knoop results were submitted to a three-way ANOVA with fixed factors the composite viscosity, load and time, and the post-hoc Tukey multiple comparison test at α=0.05. Significant differences were recorded (p<0.001) between the microhradness methodologies with two viscosities rejecting both hypotheses rejecting both null hypotheses. Among the vickers tested samples, the average recorded ranged from 164.94 (50g for 45s) to 210.33 (100g for 45s) for the medium viscosity composite and from 31.2 (100g for 30s) to 88 (500g for 45s) for a low viscosity resin. Knoop microhardness results ranged from 128.92 (500g for 45s) to 184.26 (100g for 15s) for medium viscosity composite and from 23.6 (100g for 15s) to 73.4 (500g for 30s) for flowable compositive. In a controlled in vitro experiment, the microhardness formulas mislead researchers to associate an improvement of diagonal measurements to higher load with a linear and proportional behavior. It is not recommended to clinicians compare both vickers and knoop microhardness results of composite materials without similar protocols applied in the research.
Background: Short dental implants have been considered as an alternative treatment to advanced bo... more Background: Short dental implants have been considered as an alternative treatment to advanced bone augmentation surgery in the posterior region of maxilla and mandible. Nevertheless, most previous studies clustered the clinical outcomes of short implants supporting different types of reconstructions, from single crowns to fixed partial dentures and overdentures. Also, they usually assessed survival rates of short implants based on heterogeneous data from both retrospective and prospective studies. Therefore, there is still controversy on the prognosis and biomechanical risk factors for the rehabilitation of the posterior region of maxilla and mandible with single crowns supported by short implants.
Stomatologija / issued by public institution "Odontologijos studija" ... [et al.], 2008
The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of... more The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality. The aim of this study was the processing of tomographic images in order to develop an advanced three-dimensional reconstruction of the anatomy of a molar tooth and the integration of the resulting solid with commercially available CAD/CAE software. Computed tomographic images were obtained from 0.5 mm thick slices of mandibular molar and transferred to commercial cad software. Once the point cloud data have been generated, the work on these points started to get to the solid model of the tooth with Pro/Engineer software. The obtained tooth model showed very accurate shape and dimensions, as it was obtained from rea...
Stomatologija, 2008
The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of... more The use of Finite Element Analysis (FEA) is becoming very frequent in Dentistry. However, most of the three-dimensional models presented by the literature for teeth are limited in terms of geometry. Discrepancy in shape and dimensions can cause wrong results to occur. Sharp cusps and faceted contour can produce stress concentrations, which are incoherent with the reality.
Revista Odonto Ciência, 2016
Background: Search for materials that may either replace titanium dental implants or constitute a... more Background: Search for materials that may either replace titanium dental implants or constitute an alternative as a new dental implant material has been widely studied. As well, the search for optimum biocompatible metal surfaces remains crucial. So, the aim of this work is to develop an oxidized surface layer on tantalum using plasma electrolytic oxidation (PEO) similar to those existing on oral implants been marketed today.