Andrea Kaplan - Academia.edu (original) (raw)
Papers by Andrea Kaplan
The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers us... more The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers used for pit and fissure sealing in terms of retention, marginal adaptation, caries recurrence and cracking. Eighty-three fully erupted first permanent molars were sealed, in a group of children aged 5 to 8 years. A doubleblind, single operator, paired design was used. Materials applied were Fuji IX and VII. Retention (R), presence of caries (PC), marginal discoloration (MD), marginal adaptation (MA) and cracking (C) were evaluated at 6 and 12 months using Ryge’s criteria. Data registered 6 months after treatment were: Fuji IX: R: Alpha 37, Bravo 2, Charlie: 4; PC: Alpha 43, Bravo: 0; MA: Alpha 38, Bravo: 1; MD: Alpha 39, Bravo: 0, Charlie: 0; C: Alpha 39, Bravo: 0. Fuji VII: R: Alpha 29, Bravo 4, Charlie: 7; PC: Alpha 40, Bravo: 0; MA: Alpha: 34, Bravo: 0; MD: Alpha: 34, Bravo: 0; Charlie: 0; C: Alpha 33, Bravo: 0. Results after one year were: Fuji IX: R: Alpha 33, Bravo: 3, Charlie: 9; P...
POLÍTICA EDITORIAL El objetivo de Acta Odontológica Latinoamericana (AOL) es ofrecer a la comunid... more POLÍTICA EDITORIAL El objetivo de Acta Odontológica Latinoamericana (AOL) es ofrecer a la comunidad científica un medio adecuado para la difusión internacional de los tra-bajos de investigación, realizados prefe-rentemente en Latinoamérica, dentro del campo odontológico y áreas estrechamen-te relacionadas. Publicará trabajos origi-nales de investigación básica, clínica y epidemiológica, tanto del campo biológi-co como del área de materiales dentales y técnicas especiales. La publicación de tra-bajos clínicos será considerada siempre que tengan contenido original y no sean meras presentaciones de casos o series. En principio, no se aceptarán trabajos de revi-sión bibliográfica, si bien los editores podrán solicitar revisiones de temas de particular interés. Las Comunicaciones Breves, dentro del área de interés de AOL, serán consideradas para su publicación. Solamente se aceptarán trabajos no publi-cados anteriormente, los cuales no podrán ser luego publicados en otro medio sin expres...
The aim of this study was to determine the effect of SDF on the dentin-pulp complex using two mod... more The aim of this study was to determine the effect of SDF on the dentin-pulp complex using two models: teeth after SDF application (ex vivo) and experimental animal molars. A descriptive study was performed using two models. In the first model, primary teeth (ex vivo) with enamel-dentin caries, without pulp involvement and previously treated with 38% SDF, were evaluated by means of two techniques: (a) Scanning Electron Microscopy (SEM) and energy-dispersive X-ray detector (EDS) to determine qualitative and quantitative composition, and (b) brightfield optical microscopy (OM) after decalcification. The second model used laboratory animal molars from 12 male Wistar rats. Standardized enamel-dentin cavities approximately 0.5 mm deep were made the distal fossa of the occlusal face of both first lower molars, to one of which a 38% SDF solution was applied, while the other was used as a control. Histological sections were prepared and dental pulp was evaluated qualitatively in both groups....
Journal of Petroleum Science and Engineering, 2020
Abstract A one-step procedure is presented for developing novel superhydrophobic oil-water separa... more Abstract A one-step procedure is presented for developing novel superhydrophobic oil-water separation membranes, based on composites of nanoparticles and polymers. The combination of hydrophilic particles with hydrophobic polymers allows obtaining superhydrophobic coatings on metal meshes, with chemical and physical stability. The methodology consists of coating SiO2 hydrophilic nanoparticles with two hydrophobic polymers (polydimethylsiloxane and polyvinylidene fluoride, PDMS and PVDF, respectively) on metal meshes. The nanoparticles generate roughness in the nanoscale, while the combination of PVDF and PDMS provides hydrophobicity, chemical resistance, and reinforce of mechanical properties. Membranes were characterized by XPS, SEM, TEM, FTIR, TGA, water-contact-angles (WCA) measurements, and elongation tests. The membranes present oil flux in the order of 102 Lm−2s−1, with stable performance during several months for water/oil separation tests when using saline (Na+, Cl−) and hard water (Ca+2, Mg+2) solutions. The synergetic mixture of three components, PDMS-PVDF-SiO2, provides superhydrophobic behaviour while coatings formed by any combination of only two components do not show the targeted properties.
Open Access Journal of Dental Sciences, 2016
A clinical case is presented in which the prosthetic restoration of two anterior teeth, esthetica... more A clinical case is presented in which the prosthetic restoration of two anterior teeth, esthetically compromised was required. Quartz fiber posts were used in wide non rounded root canals. A relining technique with composite resin was used to accomplish a better adaptation of the tooth posts to the internal walls of the tooth, thus reducing the required quantity of adhesive resin cement and achieve a best friction to favor fixation. In this research it is emphasized the importance of communication, teamwork and integration of prosthetic as well as endodontic concepts to confront the challenge of a better adaptation of the posts to non rounded root canals.
RSBO, 2019
Irreversible hydrocolloids have been used in dental practice for decades and their pouring time h... more Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-w...
saber.ula.ve
Palabr as clave: aleaciones de níquel-cromo, brackets de ortodoncia, corrosión por picadura.
Universitas Odontologica, Dec 27, 2011
Rev Asoc Odontol Argent, May 1, 2006
Rev Asoc Odontol Argent, Dec 1, 2005
Bol Asoc Argent Odontol Ninos, Sep 1, 2000
Acta Odontologica Latinoamericana Aol, 2010
The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers us... more The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers used for pit and fissure sealing in terms of retention, marginal adaptation, caries recurrence and cracking. Eighty-three fully erupted first permanent molars were sealed, in a group of children aged 5 to 8 years. A double-blind, single operator, paired design was used. Materials applied were Fuji IX and VII. Retention (R), presence of caries (PC), marginal discoloration (MD), marginal adaptation (MA) and cracking (C) were evaluated at 6 and 12 months using Ryge's criteria. Data registered 6 months after treatment were: Fuji IX: R: Alpha 37, Bravo 2, Charlie: 4; PC: Alpha 43, Bravo: 0; MA: Alpha 38, Bravo: 1; MD: Alpha 39, Bravo: 0, Charlie: 0; C: Alpha 39, Bravo: 0. Fuji VII: R: Alpha 29, Bravo 4, Charlie: 7; PC: Alpha 40, Bravo: 0; MA: Alpha: 34, Bravo: 0; MD: Alpha: 34, Bravo: 0, Charlie: 0; C: Alpha 33, Bravo: 0. Results after one year were: Fuji IX: R: Alpha 33, Bravo: 3, Charlie: 9; PC: Alpha 44, Bravo: 1; MA: Alpha 33, Bravo: 1; MD: Alpha: 34, Bravo: 0, Charlie: 0; C: Alpha: 34, Bravo: 0. Fuji VII: R: Alpha 22, Bravo 4, Charlie: 13, PC: Alpha 40, Bravo: 0; MA: Alpha 23, Bravo: 1; MD: Alpha 23, Bravo: 1, Charlie: 0; C: Alpha 23, Bravo: 1. Statistical analysis using Fisher test showed no significant difference (p > 0.05) for R, and MA. For PC, MD and C, values are not reported because both materials showed the same results. The second control showed no significant difference (p > 0.05) for R, MA, PC, MD and C. Results suggest no difference between Fuji IX and Fuji VII as sealants in fully erupted permanent molars.
Acta Odontologica Latinoamericana Aol, 2011
The purpose of this study was to evaluate the linear dimensional stability of different elastomer... more The purpose of this study was to evaluate the linear dimensional stability of different elastomeric impression materials over time. A metal mold was designed with its custom trays, which were made of thermoplastic sheets (Sabilex sheets 0.125 mm thick). Three impressions were taken of it with each of the following: the polyvinylsiloxane Examix-GC-(AdEx), Aquasil-Dentsply-(AdAq) and Panasil-Kettenbach-(AdPa), and the polydimethylsiloxane Densell-Dental Medrano-(CoDe), Speedex-Coltene-(CoSp) and Lastic-Kettenbach-(CoLa). All impressions were taken with putty and light-body materials using a one-step technique. Standardized digital photographs were taken at different time intervals (0, 15, 30, 60, 120 minutes; 24 hours; 7 and 14 days), using an "ad-hoc" device, and analyzed using software (Image Tool) by measuring the distance between lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. The initial and final values for mean and SD were: AdEx: 1.32 (0.01) and 1.31 (0.00); AdAq: 1.32 (0.00) and 1.32 (0.00), AdPa: 1.327 (0.006) and 1.31 (0.00); CoDe: 1.32 (0.00) and 1.32 (0.01); CoSp: 1.327 (0.006) and 1.31 (0.00), CoLa: 1.327 (0.006) and 1.303 (0.006). Statistical evaluation showed that both material and time have significant effects. Under the conditions in this study we conclude that time would significantly affect the lineal dimensional stability of elastomeric impression materials.
Orthodontics the Art and Practice of Dentofacial Enhancement, 2011
AIM: To compare the adhesive potential, the mechanics implicated in adhesive failure, and the eff... more AIM: To compare the adhesive potential, the mechanics implicated in adhesive failure, and the effect on the enamel of four brands of lingual brackets.METHODS: One hundred sixty premolars and four types of commercially available lingual brackets (STB, ORG, Magic, and Stealth) were selected. Forty brackets per manufacturer were used, half bonded directly and half indirectly. Each of these bonding groups was further subdivided: 10 brackets were bonded without treatment, while the other 10 were sandblasted. Thus, a total of four groups were created for each type of bracket: (a) sandblasted and directly bonded, (b) sandblasted and indirectly bonded, (c) not sandblasted and directly bonded, and (d) not sandblasted and indirectly bonded. Immediately after bonding, each bracket was tested for adhesion strength, and each appliance was then examined via electron microscopy to calculate the ARI.RESULTS: Statistical analysis showed a significant difference among the four bracket types; a general improvement in lingual appliance mechanical features provoked by sandblasting, albeit with some exceptions; and no significant effect of bonding method on the degree of bond strength. The ARI revealed that the most common area of adhesion crisis was at the adhesive-bracket interface.CONCLUSION: Overall, STB brackets performed better, and sandblasting proved to be an efficient way of improving the mechanical features of lingual brackets. Bonding technique, on the other hand, did not seem to exert a great influence on bonding success, and the bracket-adhesive interface was identified as the area most prone to failure.
Acta odontológica latinoamericana : AOL, 2015
The aim of this study was to evaluate in vitro the marginal microleakage of two glass ionomer mat... more The aim of this study was to evaluate in vitro the marginal microleakage of two glass ionomer materials used as pit and fissure sealants. Thirty healthy premolars extracted for orthodontic treatment were randomly assigned to two groups (n=15) and respectively sealed with two glass ionomers (Group I, Fuji VII and Group II, Fuji IX). All teeth were preserved in artificial saliva (NAF) for 10 days, thermocycled (250 cycles; 5oC, 37oC and 60oC), isolated, and immersed in 2% alcohol gentian violet blue solution for 24 h. After washing, teeth were included in acrylic resin and sectioned longitudinally in a bucco-lingual direction with a Struers-Minitom cutting device. Samples were analyzed for leakage using an optical microscope (Olympus BX- 60M). TheWilliams and Winter semi-quantitative ranked scale was used to score dye penetration. In Group I the grades were distributed as follows: Grade 1, 1 sample and Grade 3, 14 samples (Mean 2.87 Median 3, SD 0.52). In Group II: Grade 0: 4 samples,...
Acta odontológica latinoamericana : AOL, 2015
The aim of the present work was to analyze the ultrastructure and mineral composition of the surf... more The aim of the present work was to analyze the ultrastructure and mineral composition of the surface of the enamel on a molar with MIH, with and without acid etching. A permanent tooth without clinical MIH lesions (control) and a tooth with clinical diagnosis of mild and moderate MIH, with indication for extraction, were processed with and without acid etching (H3PO4 37%, 20") for observation with scanning electron microscope (SEM) ZEISS (Supra 40) and mineral composition analysis with an EDS detector (Oxford Instruments). The control enamel showed normal prismatic surface and etching pattern. The clinically healthy enamel on the tooth with MIH revealed partial loss of prismatic pattern. The mild lesion was porous with occasional cracks. The moderate lesion was more porous, with larger cracks and many scales. The mineral composition of the affected surfaces had lower Ca and P content and higher O and C. On the tooth with MIH, even on normal looking enamel, the demineralization ...
This study analyzes and quantifies the adhesion strength at interfaces between a metal and other ... more This study analyzes and quantifies the adhesion strength at interfaces between a metal and other ceramic materials. This is part of a larger work focused on the characterization of this type of interfaces applied in the area of dental materials. The experimental work consists in the preparation, manufacture and testing of specimens under "IRAM-ISO 9693: Porcelain-to-metal dental restoration systems." Standard. Proposed assays by the Standard involve the determination of the applied force causing the detachment or separation of a portion of ceramic deposited on a metal base, during a test of three-point bending. There are no precise specifications regarding the determination of this release. It is proposed as a continuation of a previously published work, using the technique of Acoustic Emission (AE) to determine more precisely the process of separation between the two materials and also to assess the conditions or type of effort that produced the event. This technique involves detection of signals caused by any source of AE such as propagation of microcracks, deformation, etc. These sources alter the material stress field, producing and propagating elastic waves that reach the surface, where they are detected by sensors. In this case, the bending test load is applied at a constant speed on the metal substrate. A load cell senses the charge. The AE is measured with an AE PAC plate of two-channel obtaining the characteristic parameters of the AE signal. Furthermore, a displacement sensor (LVDT) was implemented to correlate load with the applying tip displacement. The tests were monitored and filmed through a digital microscope.
Acta odontológica latinoamericana: AOL
ABSTRACT
The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers us... more The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers used for pit and fissure sealing in terms of retention, marginal adaptation, caries recurrence and cracking. Eighty-three fully erupted first permanent molars were sealed, in a group of children aged 5 to 8 years. A doubleblind, single operator, paired design was used. Materials applied were Fuji IX and VII. Retention (R), presence of caries (PC), marginal discoloration (MD), marginal adaptation (MA) and cracking (C) were evaluated at 6 and 12 months using Ryge’s criteria. Data registered 6 months after treatment were: Fuji IX: R: Alpha 37, Bravo 2, Charlie: 4; PC: Alpha 43, Bravo: 0; MA: Alpha 38, Bravo: 1; MD: Alpha 39, Bravo: 0, Charlie: 0; C: Alpha 39, Bravo: 0. Fuji VII: R: Alpha 29, Bravo 4, Charlie: 7; PC: Alpha 40, Bravo: 0; MA: Alpha: 34, Bravo: 0; MD: Alpha: 34, Bravo: 0; Charlie: 0; C: Alpha 33, Bravo: 0. Results after one year were: Fuji IX: R: Alpha 33, Bravo: 3, Charlie: 9; P...
POLÍTICA EDITORIAL El objetivo de Acta Odontológica Latinoamericana (AOL) es ofrecer a la comunid... more POLÍTICA EDITORIAL El objetivo de Acta Odontológica Latinoamericana (AOL) es ofrecer a la comunidad científica un medio adecuado para la difusión internacional de los tra-bajos de investigación, realizados prefe-rentemente en Latinoamérica, dentro del campo odontológico y áreas estrechamen-te relacionadas. Publicará trabajos origi-nales de investigación básica, clínica y epidemiológica, tanto del campo biológi-co como del área de materiales dentales y técnicas especiales. La publicación de tra-bajos clínicos será considerada siempre que tengan contenido original y no sean meras presentaciones de casos o series. En principio, no se aceptarán trabajos de revi-sión bibliográfica, si bien los editores podrán solicitar revisiones de temas de particular interés. Las Comunicaciones Breves, dentro del área de interés de AOL, serán consideradas para su publicación. Solamente se aceptarán trabajos no publi-cados anteriormente, los cuales no podrán ser luego publicados en otro medio sin expres...
The aim of this study was to determine the effect of SDF on the dentin-pulp complex using two mod... more The aim of this study was to determine the effect of SDF on the dentin-pulp complex using two models: teeth after SDF application (ex vivo) and experimental animal molars. A descriptive study was performed using two models. In the first model, primary teeth (ex vivo) with enamel-dentin caries, without pulp involvement and previously treated with 38% SDF, were evaluated by means of two techniques: (a) Scanning Electron Microscopy (SEM) and energy-dispersive X-ray detector (EDS) to determine qualitative and quantitative composition, and (b) brightfield optical microscopy (OM) after decalcification. The second model used laboratory animal molars from 12 male Wistar rats. Standardized enamel-dentin cavities approximately 0.5 mm deep were made the distal fossa of the occlusal face of both first lower molars, to one of which a 38% SDF solution was applied, while the other was used as a control. Histological sections were prepared and dental pulp was evaluated qualitatively in both groups....
Journal of Petroleum Science and Engineering, 2020
Abstract A one-step procedure is presented for developing novel superhydrophobic oil-water separa... more Abstract A one-step procedure is presented for developing novel superhydrophobic oil-water separation membranes, based on composites of nanoparticles and polymers. The combination of hydrophilic particles with hydrophobic polymers allows obtaining superhydrophobic coatings on metal meshes, with chemical and physical stability. The methodology consists of coating SiO2 hydrophilic nanoparticles with two hydrophobic polymers (polydimethylsiloxane and polyvinylidene fluoride, PDMS and PVDF, respectively) on metal meshes. The nanoparticles generate roughness in the nanoscale, while the combination of PVDF and PDMS provides hydrophobicity, chemical resistance, and reinforce of mechanical properties. Membranes were characterized by XPS, SEM, TEM, FTIR, TGA, water-contact-angles (WCA) measurements, and elongation tests. The membranes present oil flux in the order of 102 Lm−2s−1, with stable performance during several months for water/oil separation tests when using saline (Na+, Cl−) and hard water (Ca+2, Mg+2) solutions. The synergetic mixture of three components, PDMS-PVDF-SiO2, provides superhydrophobic behaviour while coatings formed by any combination of only two components do not show the targeted properties.
Open Access Journal of Dental Sciences, 2016
A clinical case is presented in which the prosthetic restoration of two anterior teeth, esthetica... more A clinical case is presented in which the prosthetic restoration of two anterior teeth, esthetically compromised was required. Quartz fiber posts were used in wide non rounded root canals. A relining technique with composite resin was used to accomplish a better adaptation of the tooth posts to the internal walls of the tooth, thus reducing the required quantity of adhesive resin cement and achieve a best friction to favor fixation. In this research it is emphasized the importance of communication, teamwork and integration of prosthetic as well as endodontic concepts to confront the challenge of a better adaptation of the posts to non rounded root canals.
RSBO, 2019
Irreversible hydrocolloids have been used in dental practice for decades and their pouring time h... more Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-w...
saber.ula.ve
Palabr as clave: aleaciones de níquel-cromo, brackets de ortodoncia, corrosión por picadura.
Universitas Odontologica, Dec 27, 2011
Rev Asoc Odontol Argent, May 1, 2006
Rev Asoc Odontol Argent, Dec 1, 2005
Bol Asoc Argent Odontol Ninos, Sep 1, 2000
Acta Odontologica Latinoamericana Aol, 2010
The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers us... more The aim of this study was to evaluate the clinical behavior of two conventional glass ionomers used for pit and fissure sealing in terms of retention, marginal adaptation, caries recurrence and cracking. Eighty-three fully erupted first permanent molars were sealed, in a group of children aged 5 to 8 years. A double-blind, single operator, paired design was used. Materials applied were Fuji IX and VII. Retention (R), presence of caries (PC), marginal discoloration (MD), marginal adaptation (MA) and cracking (C) were evaluated at 6 and 12 months using Ryge's criteria. Data registered 6 months after treatment were: Fuji IX: R: Alpha 37, Bravo 2, Charlie: 4; PC: Alpha 43, Bravo: 0; MA: Alpha 38, Bravo: 1; MD: Alpha 39, Bravo: 0, Charlie: 0; C: Alpha 39, Bravo: 0. Fuji VII: R: Alpha 29, Bravo 4, Charlie: 7; PC: Alpha 40, Bravo: 0; MA: Alpha: 34, Bravo: 0; MD: Alpha: 34, Bravo: 0, Charlie: 0; C: Alpha 33, Bravo: 0. Results after one year were: Fuji IX: R: Alpha 33, Bravo: 3, Charlie: 9; PC: Alpha 44, Bravo: 1; MA: Alpha 33, Bravo: 1; MD: Alpha: 34, Bravo: 0, Charlie: 0; C: Alpha: 34, Bravo: 0. Fuji VII: R: Alpha 22, Bravo 4, Charlie: 13, PC: Alpha 40, Bravo: 0; MA: Alpha 23, Bravo: 1; MD: Alpha 23, Bravo: 1, Charlie: 0; C: Alpha 23, Bravo: 1. Statistical analysis using Fisher test showed no significant difference (p > 0.05) for R, and MA. For PC, MD and C, values are not reported because both materials showed the same results. The second control showed no significant difference (p > 0.05) for R, MA, PC, MD and C. Results suggest no difference between Fuji IX and Fuji VII as sealants in fully erupted permanent molars.
Acta Odontologica Latinoamericana Aol, 2011
The purpose of this study was to evaluate the linear dimensional stability of different elastomer... more The purpose of this study was to evaluate the linear dimensional stability of different elastomeric impression materials over time. A metal mold was designed with its custom trays, which were made of thermoplastic sheets (Sabilex sheets 0.125 mm thick). Three impressions were taken of it with each of the following: the polyvinylsiloxane Examix-GC-(AdEx), Aquasil-Dentsply-(AdAq) and Panasil-Kettenbach-(AdPa), and the polydimethylsiloxane Densell-Dental Medrano-(CoDe), Speedex-Coltene-(CoSp) and Lastic-Kettenbach-(CoLa). All impressions were taken with putty and light-body materials using a one-step technique. Standardized digital photographs were taken at different time intervals (0, 15, 30, 60, 120 minutes; 24 hours; 7 and 14 days), using an "ad-hoc" device, and analyzed using software (Image Tool) by measuring the distance between lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. The initial and final values for mean and SD were: AdEx: 1.32 (0.01) and 1.31 (0.00); AdAq: 1.32 (0.00) and 1.32 (0.00), AdPa: 1.327 (0.006) and 1.31 (0.00); CoDe: 1.32 (0.00) and 1.32 (0.01); CoSp: 1.327 (0.006) and 1.31 (0.00), CoLa: 1.327 (0.006) and 1.303 (0.006). Statistical evaluation showed that both material and time have significant effects. Under the conditions in this study we conclude that time would significantly affect the lineal dimensional stability of elastomeric impression materials.
Orthodontics the Art and Practice of Dentofacial Enhancement, 2011
AIM: To compare the adhesive potential, the mechanics implicated in adhesive failure, and the eff... more AIM: To compare the adhesive potential, the mechanics implicated in adhesive failure, and the effect on the enamel of four brands of lingual brackets.METHODS: One hundred sixty premolars and four types of commercially available lingual brackets (STB, ORG, Magic, and Stealth) were selected. Forty brackets per manufacturer were used, half bonded directly and half indirectly. Each of these bonding groups was further subdivided: 10 brackets were bonded without treatment, while the other 10 were sandblasted. Thus, a total of four groups were created for each type of bracket: (a) sandblasted and directly bonded, (b) sandblasted and indirectly bonded, (c) not sandblasted and directly bonded, and (d) not sandblasted and indirectly bonded. Immediately after bonding, each bracket was tested for adhesion strength, and each appliance was then examined via electron microscopy to calculate the ARI.RESULTS: Statistical analysis showed a significant difference among the four bracket types; a general improvement in lingual appliance mechanical features provoked by sandblasting, albeit with some exceptions; and no significant effect of bonding method on the degree of bond strength. The ARI revealed that the most common area of adhesion crisis was at the adhesive-bracket interface.CONCLUSION: Overall, STB brackets performed better, and sandblasting proved to be an efficient way of improving the mechanical features of lingual brackets. Bonding technique, on the other hand, did not seem to exert a great influence on bonding success, and the bracket-adhesive interface was identified as the area most prone to failure.
Acta odontológica latinoamericana : AOL, 2015
The aim of this study was to evaluate in vitro the marginal microleakage of two glass ionomer mat... more The aim of this study was to evaluate in vitro the marginal microleakage of two glass ionomer materials used as pit and fissure sealants. Thirty healthy premolars extracted for orthodontic treatment were randomly assigned to two groups (n=15) and respectively sealed with two glass ionomers (Group I, Fuji VII and Group II, Fuji IX). All teeth were preserved in artificial saliva (NAF) for 10 days, thermocycled (250 cycles; 5oC, 37oC and 60oC), isolated, and immersed in 2% alcohol gentian violet blue solution for 24 h. After washing, teeth were included in acrylic resin and sectioned longitudinally in a bucco-lingual direction with a Struers-Minitom cutting device. Samples were analyzed for leakage using an optical microscope (Olympus BX- 60M). TheWilliams and Winter semi-quantitative ranked scale was used to score dye penetration. In Group I the grades were distributed as follows: Grade 1, 1 sample and Grade 3, 14 samples (Mean 2.87 Median 3, SD 0.52). In Group II: Grade 0: 4 samples,...
Acta odontológica latinoamericana : AOL, 2015
The aim of the present work was to analyze the ultrastructure and mineral composition of the surf... more The aim of the present work was to analyze the ultrastructure and mineral composition of the surface of the enamel on a molar with MIH, with and without acid etching. A permanent tooth without clinical MIH lesions (control) and a tooth with clinical diagnosis of mild and moderate MIH, with indication for extraction, were processed with and without acid etching (H3PO4 37%, 20") for observation with scanning electron microscope (SEM) ZEISS (Supra 40) and mineral composition analysis with an EDS detector (Oxford Instruments). The control enamel showed normal prismatic surface and etching pattern. The clinically healthy enamel on the tooth with MIH revealed partial loss of prismatic pattern. The mild lesion was porous with occasional cracks. The moderate lesion was more porous, with larger cracks and many scales. The mineral composition of the affected surfaces had lower Ca and P content and higher O and C. On the tooth with MIH, even on normal looking enamel, the demineralization ...
This study analyzes and quantifies the adhesion strength at interfaces between a metal and other ... more This study analyzes and quantifies the adhesion strength at interfaces between a metal and other ceramic materials. This is part of a larger work focused on the characterization of this type of interfaces applied in the area of dental materials. The experimental work consists in the preparation, manufacture and testing of specimens under "IRAM-ISO 9693: Porcelain-to-metal dental restoration systems." Standard. Proposed assays by the Standard involve the determination of the applied force causing the detachment or separation of a portion of ceramic deposited on a metal base, during a test of three-point bending. There are no precise specifications regarding the determination of this release. It is proposed as a continuation of a previously published work, using the technique of Acoustic Emission (AE) to determine more precisely the process of separation between the two materials and also to assess the conditions or type of effort that produced the event. This technique involves detection of signals caused by any source of AE such as propagation of microcracks, deformation, etc. These sources alter the material stress field, producing and propagating elastic waves that reach the surface, where they are detected by sensors. In this case, the bending test load is applied at a constant speed on the metal substrate. A load cell senses the charge. The AE is measured with an AE PAC plate of two-channel obtaining the characteristic parameters of the AE signal. Furthermore, a displacement sensor (LVDT) was implemented to correlate load with the applying tip displacement. The tests were monitored and filmed through a digital microscope.
Acta odontológica latinoamericana: AOL
ABSTRACT