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1.
Biomolecules ; 10(3)2020 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-32121647

RESUMEN

Bone defects cause aesthetic and functional changes that affect the social, economic and especially the emotional life of human beings. This complication stimulates the scientific community to investigate strategies aimed at improving bone reconstruction processes using complementary therapies. Photobiomodulation therapy (PBMT) and the use of new biomaterials, including heterologous fibrin biopolymer (HFB), are included in this challenge. The objective of the present study was to evaluate the influence of photobiomodulation therapy on bone tibial reconstruction of rats with biomaterial consisting of lyophilized bovine bone matrix (BM) associated or not with heterologous fibrin biopolymer. Thirty male rats were randomly separated into three groups of 10 animals. In all animals, after the anesthetic procedure, a noncritical tibial defect of 2 mm was performed. The groups received the following treatments: Group 1: BM + PBMT, Group 2: BM + HFB and Group 3: BM + HFB + PBMT. The animals from Groups 1 and 3 were submitted to PBMT in the immediate postoperative period and every 48 h until the day of euthanasia that occurred at 14 and 42 days. Analyses by computed microtomography (µCT) and histomorphometry showed statistical difference in the percentage of bone formation between Groups 3 (BM + HB + PBMT) and 2 (BM + HFB) (26.4% ± 1.03% and 20.0% ± 1.87%, respectively) at 14 days and at 42 days (38.2% ± 1.59% and 31.6% ± 1.33%, respectively), and at 42 days there was presence of bone with mature characteristics and organized connective tissue. The µCT demonstrated BM particles filling the defect and the deposition of new bone in the superficial region, especially in the ruptured cortical. It was concluded that the association of PBMT with HFB and BM has the potential to assist in the process of reconstructing bone defects in the tibia of rats.

2.
Braz Oral Res ; 33: e097, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31664360

RESUMEN

To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys - R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.


Asunto(s)
Aleaciones/química , Aleaciones Dentales/química , Instrumentos Dentales , Preparación del Conducto Radicular/instrumentación , Análisis de Varianza , Diseño de Equipo , Análisis de Falla de Equipo , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Valores de Referencia , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Estrés Mecánico , Propiedades de Superficie , Torque
3.
Am J Transl Res ; 11(8): 5261-5271, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31497239

RESUMEN

The use of biomaterials in medical and dental areas has become increasingly important due to the need to restore areas with bone loss or defects. This study analyzed the use of a new elastin polymer matrix combined with Bone Morphogenetic Protein for the repair of cranial defects in rats. Thirty rats were divided into five groups: control (C) defect without graft, E24 (defect filled with elastin matrix submitted to alkaline hydrolysis at 50°C for 24 h), E24/BMP (defect filled with elastin matrix treated at 50°C for 24 h plus BMP), E96 (defect filled with elastin matrix treated at 37°C for 96 h) and E96/BMP (defect filled with elastin matrix treated at 37°C for 96 h plus BMP). The animals were killed after 6 weeks. In the histological and microtomographic analysis, all groups showed bone growth from the defect margins remaining in this region without a marked inflammatory process, but in the E96/BMP group the lamellae were thicker and the collagen fibers more organized. Histometrically, the same group presented higher percentage of new formation (43.25 ± 3.72) in relation to the other groups. It was concluded that the support and delivery system formed by the elastin matrix associated with BMPs had a positive effect on the bone repair process.

4.
Int J Mol Sci ; 20(7)2019 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-30974743

RESUMEN

Fibrin sealants derived from human blood can be used in tissue engineering to assist in the repair of bone defects. The objective of this study was to evaluate the support system formed by a xenograft fibrin sealant associated with photobiomodulation therapy of critical defects in rat calvaria. Thirty-six rats were divided into four groups: BC (n = 8), defect filled with blood clot; FSB (n = 10), filled with fibrin sealant and xenograft; BCPBMT (n = 8), blood clot and photobiomodulation; FSBPBMT (n = 10), fibrin sealant, xenograft, and photobiomodulation. The animals were killed after 14 and 42 days. In the histological and microtomographic analysis, new bone formation was observed in all groups, limited to the defect margins, and without complete wound closure. In the FSB group, bone formation increased between periods (4.3 ± 0.46 to 6.01 ± 0.32), yet with lower volume density when compared to the FSBPBMT (5.6 ± 0.45 to 10.64 ± 0.97) group. It was concluded that the support system formed by the xenograft fibrin sealant associated with the photobiomodulation therapy protocol had a positive effect on the bone repair process.


Asunto(s)
Regeneración Ósea , Trasplante Óseo , Adhesivo de Tejido de Fibrina/farmacología , Terapia por Luz de Baja Intensidad , Animales , Regeneración Ósea/efectos de los fármacos , Regeneración Ósea/efectos de la radiación , Humanos , Masculino , Ratas , Ratas Wistar
5.
Braz Oral Res ; 33: e011, 2019 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-30758408

RESUMEN

To evaluate the influence of novel ultrasonic tips as an auxiliary method for the rotary preparation of flattened/oval-shaped canals. Forty-five mandibular incisors were selected and divided into one of three experimental groups (n = 15): Group PFCP - ProDesign Logic 25/.05 + Flatsonic + Clearsonic + Prodesign Logic 40/.01; Group FCP - Flatsonic + Clearsonic + ProDesign Logic 40/.01; and Group PP - Prodesign Logic 25/.05 + Prodesign Logic 40/.05. The teeth were scanned preoperatively and postoperatively using microcomputed tomography. The percentage values for increase in volume, non-instrumented surface area, dentin removal, degree of canal transportation, and centering ratio between the experimental groups were examined. Data were analyzed using the non-parametric Kruskal-Wallis and Dunn's tests (p < 0.05). Group PFCP showed the greatest volume increase in the total portion of the root canal and the lowest percentage of non-instrumented surface area. Regarding the degree of transportation in the buccolingual direction, statistically significant differences between groups PFCP and PP were observed at the coronal third of the canal. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. As for the centering ratio, statistically significant differences were found in the buccolingual direction. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. The use of novel ultrasonic tips combined with rotary instruments in group PFCP provided a significant increase in volume and reduced the percentage of non-instrumented areas during the preparation of flattened/oval-shaped canals.


Asunto(s)
Cavidad Pulpar/anatomía & histología , Preparación del Conducto Radicular/instrumentación , Terapia por Ultrasonido/instrumentación , Instrumentos Dentales/normas , Dentina/cirugía , Diseño de Equipo , Humanos , Microscopía Electrónica de Rastreo , Valores de Referencia , Reproducibilidad de los Resultados , Estadísticas no Paramétricas , Propiedades de Superficie , Resultado del Tratamiento , Microtomografía por Rayos X/métodos
6.
Clin Oral Investig ; 23(7): 3047-3052, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30397733

RESUMEN

OBJECTIVES: The aim of this study was to evaluate the impact of body temperature on the cyclic fatigue resistance of different NiTi alloys used for the manufacturing of Reciproc Blue R25 (RB 25.08; VDW, Munich, Germany), X1 Blue File 25 (X1 25.06; MK Life Medical and Dental Products, Porto Alegre, Brazil) and WaveOne Gold Primary (WOG 25.07; Dentsply Maillefer, Ballaigues, Switzerland). MATERIALS AND METHODS: Sixty instruments of the RB 25.08, X1 25.06 and WOG 25.07 systems were used (n = 20). Cyclic fatigue tests were performed at room temperature (20° ± 1 °C) and at body temperature (37° ± 1 °C). The instruments were reciprocated until fracture occurred in an artificial stainless steel canal with a 60° angle and a 5-mm radius of curvature. The time to fracture (TTF) was recorded. Also, the number of cycles to fracture (NCF) was calculated. Data were analysed using one-way ANOVA and Tukey's tests for inter-group comparison at both temperatures and for the reduction of cyclic fatigue at body temperature. For intra-group comparison at the different temperatures, the unpaired t test was used. RESULTS: The cyclic fatigue test at 20 °C showed that RB 25.08 and X1 25.06 presented significantly higher TTF and NCF than WOG 25.07 (P < 0.05). At 37 °C, all groups presented significant reduction of TTF and NCF (P < 0.05). RB 25.08 presented significant higher TTF than WOG 25.07 (P < 0.05). Regarding the NCF, there was no significant difference among the groups (P > 0.05). The WOG 25.07 presented the lowest percentage reduction of cyclic fatigue (P < 0.05). CONCLUSION: The body temperature treatment caused a marked reduction of the cyclic fatigue resistance for all reciprocating instruments tested. The RB 25.08 and X1 25.06 systems presented similar results at both temperatures tested. However, WOG 25.07 presented the lowest percentage reduction in fatigue resistance at body temperature. CLINICAL RELEVANCE: The cyclic fatigue resistance of NiTi reciprocating instruments has been evaluated at room temperature. However, the fatigue resistance significantly decreases upon exposure to body temperature, which could affect the mechanical behaviour of the NiTi instruments during root canal preparation.


Asunto(s)
Instrumentos Dentales , Preparación del Conducto Radicular , Temperatura Ambiental , Aleaciones Dentales , Diseño de Equipo , Falla de Equipo , Ensayo de Materiales , Estrés Mecánico , Titanio
7.
Braz. oral res. (Online) ; 33: e011, 2019. tab, graf
Artículo en Inglés | LILACS-Express | ID: biblio-989484

RESUMEN

Abstract To evaluate the influence of novel ultrasonic tips as an auxiliary method for the rotary preparation of flattened/oval-shaped canals. Forty-five mandibular incisors were selected and divided into one of three experimental groups (n = 15): Group PFCP - ProDesign Logic 25/.05 + Flatsonic + Clearsonic + Prodesign Logic 40/.01; Group FCP - Flatsonic + Clearsonic + ProDesign Logic 40/.01; and Group PP - Prodesign Logic 25/.05 + Prodesign Logic 40/.05. The teeth were scanned preoperatively and postoperatively using microcomputed tomography. The percentage values for increase in volume, non-instrumented surface area, dentin removal, degree of canal transportation, and centering ratio between the experimental groups were examined. Data were analyzed using the non-parametric Kruskal-Wallis and Dunn's tests (p < 0.05). Group PFCP showed the greatest volume increase in the total portion of the root canal and the lowest percentage of non-instrumented surface area. Regarding the degree of transportation in the buccolingual direction, statistically significant differences between groups PFCP and PP were observed at the coronal third of the canal. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. As for the centering ratio, statistically significant differences were found in the buccolingual direction. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. The use of novel ultrasonic tips combined with rotary instruments in group PFCP provided a significant increase in volume and reduced the percentage of non-instrumented areas during the preparation of flattened/oval-shaped canals.

8.
Full dent. sci ; 11(41): 119-126, 2019. ilus
Artículo en Portugués | BBO - Odontología | ID: biblio-1052061

RESUMEN

O insucesso do tratamento endodôntico é descrito como a persistência de sinais clínicos e radiográficos e da sintomatologia dolorosa pós-tratamento. O tratamento (cirúrgico ou não cirúrgico) e o prognóstico dependem da causa e das condições presentes do dente. O objetivo deste estudo foi relatar um caso clínico de fracasso de um tratamento endodôntico associado a uma perfuração radicular, relatando sua etiologia, diagnóstico, tratamento e acompanhamento. Paciente de 32 anos, sexo masculino, compareceu à clínica de Endodontia da Faculdade de Odontologia de Bauru, com queixa de desconforto na região de incisivo lateral superior direito, para avaliação. O exame radiográfico revelou presença de lesão periapical e obturação insatisfatória, enquanto que o exame clínico demonstrou presença de bolsa periodontal, discreta mobilidade, sensibilidade à percussão vertical e à palpação apical. O exame tomográfico mostrou perfuração na região vestibular da raiz associada a um extravasamento de material obturador, sugerindo ser a causa do fracasso do tratamento endodôntico primário. A cirurgia foi indicada como intervenção. A perfuração foi cirurgicamente exposta, limpa e selada com SuperEBA, enquanto que o canal foi simultaneamente retratado e obturado. No final, um enxerto ósseo e uma membrana foram utilizados para estimular uma regeneração tecidual guiada da região. Em um acompanhamento clínico e radiográfico de 4 anos, demonstrou-se reparo satisfatório do tecido ósseo com ausência de sintomatologia dolorosa. O diagnóstico preciso e o tratamento cirúrgico com obturação simultânea do canal radicular foram determinantes para o reparo satisfatório da lesão periapical e remissão dos sinais e sintomas de inflamação (AU).


The insucess of the endodontic treatment is described as the persistence of clinical and radiographic signs and painful symptomatology post-treatment. Its therapy (non-surgical and surgical treatment) and prognosis depend on the cause and tooth conditions. The aim of this study was report a case of an endodontic treatment failure associated with a root perforation retreating its etiology, diagnosis, management, and overcome. A 32-years old male patient was reffered to clinic of endodontics in Bauru School of Dentistry with complaint of discomfort in the region of maxillary right lateral incisor for evaluation. The radiographic revealed the presence of periapical lesion and unsatisfactory filling, while the clinical examination revealed the presence of periodontal pocket, discrete mobility, sensitivity to vertical percussion and to apical palpation. The tomographic examination showed a perforation on vestibular region of the root associated with filling material extravasation suggesting it be the cause of the failure of the primary endodontic treatment. The surgery was indicated as intervention. The perforation was surgically exhibited, cleaned up, and sealed with SuperEBA, while the root canal was simultaneously retreated and filled. Finally, a bone grafting and a membrane insertion were performed to induce tissue regeneration of the region. Four years follow up x-ray and clinical exam showed satisfactory repair of the hard tissue with absence of painful symptomatology. The correctly diagnosis and the surgical treatment with simultaneous filling of root canal were determinant for satisfactory repair of periapical lesion and the resolution of inflammation signs and symptomatology (AU).


Asunto(s)
Humanos , Masculino , Adulto , Tratamiento del Conducto Radicular , Cavidad Pulpar , Endodoncia , Cirugía Bucal , Tomografía Computarizada de Haz Cónico/instrumentación
9.
Braz. oral res. (Online) ; 33: e097, 2019. tab, graf
Artículo en Inglés | LILACS-Express | ID: biblio-1039297

RESUMEN

Abstract To evaluate the torsional properties of engine-driven pathfinding instruments manufactured from different NiTi alloys - R-Pilot (tip size 12.5;.04 taper; M-Wire) and One G (tip size 14;.03 taper; Conventional NiTi). A total of 40 NiTi instruments from engine-driven pathfinding instruments (n = 20) were used. The torsion tests followed ISO 3630-1 (1992). Three millimeters of each instrument tip was fastened to a small load cell by a lever arm linked to the axis of torsion. During the test, the torsion testing machine software measured the maximum torsional strength and angle of rotation (0) before instrument failure. The fractured surface of each instrument was assessed by scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area and the metal mass volume of each instrument 3 mm from the tip. Data were analyzed using a t-test, with significance level set at 5%. R-pilot had significantly higher torsional strength than did One G (p < 0.05). Regarding the angle of rotation to fracture, One G had higher angles than did R-Pilot (p < 0.05). The supplementary examination showed that R-Pilot had the highest cross-sectional area and volume of metal mass at 3 mm from the tip (p < 0.05). R-pilot (M-Wire NiTi alloy) had a significantly higher torsional strength and One-G (superelastic NiTi alloy) had the highest angle of rotation to fracture.

10.
J Endod ; 44(12): 1862-1866, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30390974

RESUMEN

INTRODUCTION: The purpose of this study was to evaluate the accuracy of small-volume cone-beam computed tomography (CBCT) to detect and measure isthmi in the apical root canals of mandibular molars by using micro-computed tomography (µ-CT) as the reference standard. METHODS: Forty mandibular first molars selected on the basis of µ-CT scan and presenting isthmi in the apical 3-mm mesial roots were scanned by using the highest-resolution settings of a small-volume CBCT unit. Isthmi lengths were measured and compared between both µ-CT and CBCT images to study the accuracy of CBCT readings. Quantitative data for sensitivity rate were depicted as percentage value with 95% confidence interval. Results were analyzed by using linear regression between true lengths (µ-CT) and CBCT lengths, Bland-Altman plot and t test, at α = 0.05. RESULTS: CBCT sensitivity for isthmi detection was 65% (95% confidence interval, 0.4667-0.8333). An average of 74.7% of the lengths could be measured, and differences among the lengths in µ-CT and CBCT were significant (P < .05; mean, 0.756 ± 0.655; t test), showing that there was no agreement between both methods. CONCLUSIONS: Accuracy of identifying apical isthmi of mandibular molars was highly influenced by the evaluation method. Small-volume CBCT imaging could not detect and measure apical isthmi length accurately. Moreover, using high-resolution settings in CBCT, it was not reliable to forecast the actual apical root canal anatomy.


Asunto(s)
Tomografía Computarizada de Haz Cónico/métodos , Cavidad Pulpar/anatomía & histología , Intensificación de Imagen Radiográfica , Ápice del Diente/anatomía & histología , Humanos , Mandíbula , Diente Molar/anatomía & histología , Sensibilidad y Especificidad
11.
J Conserv Dent ; 21(4): 383-387, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30122818

RESUMEN

Aim: The aim of this study was compare the capacity of different irrigation protocols for debris removal from artificial grooves and assess the effectiveness of Easy Clean used in different kinematics by means of micro-CT. Methodology: Fifty acrylic prototyped maxillary incisors were instrumented and included in a muffle. The specimens were longitudinally sectioned, and a longitudinal groove was made on the inner surface of the root canal in one of hemisections, and the dentin debris was inserted into the grooves. The specimens were divided into five groups (n = 10): G1: Conventional with open-ended needle; G2: Conventional with double side-vented needle; G3: Easy Clean in reciprocating movement; G4: Easy clean in continuous rotation (ECCR); and G5: Passive ultrasonic irrigation (PUI). All specimens were scanned using microcomputed tomography before and after the irrigation technique and calculated the volume (mm3) of dentin debris. The paired t-test and post hoc Tukey test were the statistical tests used, with significance set at 5%. Results: There were no significant difference (P > 0.05) between PUI and ECCR. ECCR was significantly (P < 0.05) more effective than the groups of conventional irrigation techniques. Conclusions: PUI and ECCR favored the removal of a larger volume of dentin debris from the groove.

12.
Braz Oral Res ; 32: e88, 2018 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-30110086

RESUMEN

The aim of this study was to evaluate the influence of a novel ultrasonic tip as an auxiliary method for removing filling material from flattened/oval-shaped canals. The null hypothesis tested was that this method does not influence removing the filling material in flattened/oval-shaped canals. Forty-five mandibular incisors were selected and randomly divided into three experimental groups (n = 15) according to different protocols for removing root canal filling material. Group R: Reciproc R25/.08, Group RC: Reciproc R25/.08 + Clearsonic tip, and Group CR: Clearsonic tip + Reciproc R25/.08. The teeth were scanned pre and post-operatively by means of a micro-computed tomography system. Data were analyzed using non-parametric Kruskal-Wallis and Dunn tests (p < 0.05). The percentage of residual root canal filling material between the experimental groups was examined. Statistically significant differences between the experimental groups were found in the root canal. Group R had the highest percentage of residual root canal filling material when compared with Groups RC and CR. The lowest percentage of residual root canal filling material was observed in Group CR. In the apical third of the root canal, statistically significant differences were found between the different protocols. The use of the ClearSonic tip followed by the Reciproc 25/.08 file to remove filling material resulted in the lowest percentage of residuals in the whole root canal and in the apical third.


Asunto(s)
Instrumentos Dentales , Cavidad Pulpar/anatomía & histología , Materiales de Obturación del Conducto Radicular , Preparación del Conducto Radicular/instrumentación , Ultrasonido/instrumentación , Análisis de Varianza , Diseño de Equipo , Humanos , Incisivo/anatomía & histología , Ensayo de Materiales , Valores de Referencia , Reproducibilidad de los Resultados , Retratamiento , Preparación del Conducto Radicular/métodos , Estadísticas no Paramétricas , Ultrasonido/métodos , Microtomografía por Rayos X
13.
J Endod ; 44(9): 1425-1429, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30078572

RESUMEN

INTRODUCTION: This study compared the cyclic fatigue and the canal transportation promoted by Twisted File (TF) Adaptive and Navigator EVO systems when used with 2 different motions. METHODS: Forty mesiobuccal roots of maxillary molars were scanned by using micro-computed tomography imaging before and after root canal preparation with the 2 instrument systems used with 2 motions (adaptive and continuous rotation). Samples were divided into 4 groups: TFA, TF Adaptive instruments under adaptive motion; TFC, TF Adaptive instruments under continuous motion; NA, Navigator instruments under adaptive motion; and NC, Navigator instruments under continuous motion. Root canals were prepared until 35.04 instruments. Apical transportation was analyzed by using micro-computed tomography at 3 levels: 3, 6, and 9 mm from the apex. The cyclic fatigue tests were performed by using a custom-made device. Ten instruments of each brand were activated by using a 6:1 reduction handpiece powered by a torque-controlled motor using the preset programs "custom mode" and "TF Adaptive" to activate 25.06 and 35.04 instruments. Kruskal-Wallis and Dunn tests were used to assess canal transportation, centering ability, and canal volume. The Student t test was used to evaluate cyclic fatigue (P = .05). RESULTS: At 3 and 9 mm, the canal transportation and centering ability were similar in all groups (P > .05). At 6 mm, TFC presented higher canal transportation toward furcal region than NA and NC (P < .05). After canal preparation, TFA promoted great dentinal excision, presenting higher canal volume than NA and NC (P < .05). Higher cyclic fatigue resistance was observed under continuous than adaptive motion regardless of system or tip/diameter of the instrument (P < .05). CONCLUSIONS: Both systems can be used under adaptive or continuous rotation. However, the life span of the instruments was higher when used under continuous rotation. Small canal transportation occurred when mesiobuccal root canals from maxillary molars were prepared until 35.04 instruments.


Asunto(s)
Análisis de Falla de Equipo , Falla de Equipo , Obturación del Conducto Radicular/instrumentación , Preparación del Conducto Radicular/instrumentación , Aleaciones , Humanos , Movimiento (Física) , Rotación
14.
ROBRAC ; 27(81): 73-76, Abr. -Jun 2018. tab, ilus
Artículo en Portugués | LILACS-Express | ID: biblio-967551

RESUMEN

Introdução: O objetivo deste estudo foi avaliar a associação do hipoclorito de sódio e EDTANa4 como irrigante comparado ao EDTANa3 quanto a capacidade de limpeza, preparo biomecânico e na irrigação final, associados ou não com a agitação ultrassônica. Materiais e Método: Foram utilizados 40 pré-molares inferiores, instrumentados e analisados em MEV para comprovar a formação de smear-layer. Realizou-se então os protocolos de irrigação utilizando diferentes associações, associadas ou não a agitação ultrassônica. Resultados: O EDTA trissódico agitado ou não com ultrassom, favoreceu limpeza significante (P<0.05) apenas nos terços médio e cervical, enquanto que para o EDTA tetrassódico sem agitação a limpeza foi significante (P<0.05) apenas no terço médio. Comparando os irrigantes, independente do método de irrigação, houve diferença estatisticamente significante (P<0.05) apenas no terço médio na comparação entre o EDTA trissódico pela irrigação convencional e EDTA tetrassódico pela irrigação convencional. Conclusão: O EDTA trissódico favoreceu uma melhor limpeza em relação ao EDTA tetrassódico, principalmente no terço médio. Além disso, a agitação ultrassônica não favoreceu melhor limpeza de parede em relação à irrigação convencional.


AIM: The aim of this study was to evaluate the efficacy of Sodium Hypochlorite associated or not with Tetrasodium EDTA in smear layer removal during root canal preparation. Additionally, to compare the cleaness of dentin walls after a final irrigation of Trisodium EDTA and Sodium Hypochlorite associated with Tetrasodium EDTA, activated or not by utrasonic. Methods: 40 mandibular premolars were used, which were divided in 2 groups (n=20). G1 the root canals were instrumented using Sodium hypochlorite and G2 using Sodium hypochlorite associated with Tetrasodium EDTA. Then, the dentin walls were analyzed by Scanning Electron Microscopy (SEM) to assess presence or not of smear-layer. After this step, it was performed a final irrigation of Trisodium EDTA and Sodium Hypochlorite associated with Tetrasodium EDTA, activated or not by utrasonic. Results: The was no significantly difference between the Sodium Hypochlorite and Sodium Hypochlorite associated with Tetrasodium EDTA during root canal preparation (P>0.05). Regarding the final irrigation, the Trisodium EDTA presented significantly difference when activated ultrasonic in the coronal and middle thirds (P<0.05). The association of Sodium Hypochlorite and Tetrasodium EDTA presented significantly difference only in the middle third without ultrasonic activation (P<0.05). In general, the Trisodium EDTA favoured better smear layer removal than Tetrasodium EDTA. Conclusion: The Trisodium EDTA favored a better smear layer ramoval than Tetrasodium EDTA, mainly in the middle third. In addition, ultrasonic activation improved the smear layer removal in comparison with conventional irrigation.

15.
Restor Dent Endod ; 43(2): e23, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29765903

RESUMEN

Objectives: This study evaluated the effect of ultrasonic agitation of mineral trioxide aggregate (MTA), calcium silicate-based cement (CSC), and Sealer 26 (S26) on adaptation at the cement/dentin interface and push-out bond strength. Materials and Methods: Sixty maxillary canines were divided into 6 groups (n = 10): MTA, S26, and CSC, with or without ultrasonic activation (US). After obturation, the apical portions of the teeth were sectioned, and retrograde cavities were prepared and filled with cement by hand condensation. In the US groups, the cement was activated for 60 seconds: 30 seconds in the mesio-distal direction and 30 seconds in the buccal-lingual direction, using a mini Irrisonic insert coupled with the ultrasound transducer. After the materials set, 1.5-mm thick sections were obtained from the apexes. The presence of gaps and the bond between cement and dentin were analyzed using low-vacuum scanning electron microscopy. Push-out bond strength was measured using a universal testing machine. Results: Ultrasonic agitation increased the interfacial adaptation of the cements. The S26 US group showed a higher adaptation value than MTA (p < 0.05). US improved the push-out bond strength for all the cements (p < 0.05). Conclusions: The US of retrograde filling cements enhanced the bond to the dentin wall of the root-end filling materials tested.

16.
Clin Oral Investig ; 22(4): 1865-1871, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29224061

RESUMEN

OBJECTIVES: The aim of this study was to evaluate the cyclic and torsional fatigue resistance of the reciprocating single-file systems Reciproc Blue 25.08 (VDW GmbH, Munich, Germany), Prodesign R 25.06 (Easy Dental Equipment, Belo Horizonte, Brazil), and WaveOne Gold 25.07 (Dentsply/Tulsa Dental Specialties, Tulsa, OK, USA). MATERIALS AND METHODS: Sixty reciprocating instruments of the systems Reciproc Blue R25 (RB #25 .08 taper), Prodesign R (PDR #25 .06 taper), and WaveOne Gold (WOG #25 .07 taper) (n = 20) were used. Cyclic fatigue resistance testing was performed by measuring the time to failure in an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius located 5 mm from the tip (n = 10). The torsional test (ISO 3630-1) evaluated the torque and angle of rotation at failure of new instruments (n = 10) in the portion 3 mm from the tip. The fractured surface of each fragment was also observed using scanning electron microscopy (SEM). In addition, a supplementary examination was performed to measure the cross-sectional area of each instrument 3 and 5 mm from the tip. The data were analyzed using one-way ANOVA and Tukey's test, and the level of significance was set at 5%. RESULTS: The cyclic fatigue resistance values of PDR 25.06 were significantly higher (P < 0.05). RB 25.08 showed higher fatigue resistance than WOG 25.07 (P < 0.05). The torsional test showed that PDR 25.06 had lower torsional strength (P < 0.05). No differences were observed between RB 25.08 and WOG 25.07 (P > 0.05). PDR 25.06 showed higher angular rotation values than RB 25.08 and WOG 25.07 (P < 0.05). RB 25.08 presented higher angular rotation than WOG 25.07 (P < 0.05). The cross-sectional area analysis showed that PDR 25.06 presented the smallest cross-sectional areas at 3 and 5 mm from the tip (P < 0.05). CONCLUSION: PDR 25.06 presented the highest cyclic fatigue resistance and angular rotation until fracture compared to RB 25.08 and WOG 25.07. In addition, RB 25.08 and WOG 25.07 had higher torsional strength than PDR 25.06. CLINICAL RELEVANCE: In endodontic practice, thermally treated reciprocating instruments have been used for the root canal preparation of curved and constricted canals; therefore, these instruments should present high flexibility and suitable torsional strength to minimize the risk of instrument fracture.


Asunto(s)
Aleaciones Dentales/química , Instrumentos Dentales , Análisis de Falla de Equipo , Níquel/química , Titanio/química , Diseño de Equipo , Calor , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Torque , Torsión Mecánica
17.
J Endod ; 44(3): 501-505, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29254816

RESUMEN

INTRODUCTION: The aim of this study was to evaluate some of the physicochemical properties of a new root canal sealer. METHODS: The sealers tested were Sealer Plus compared with AH Plus. For the radiopacity, flow, solubility, and fabrication of test specimens relative to setting times, the American National Standards Institute/American Dental Association No. 57 (2000) and International Organization for Standardization 6876 (2012) specifications were followed. To measure the initial and final setting times, the ASTM C266/2008 standard was used. pH was evaluated in the time intervals of 3, 24, 72, and 168 hours. Statistical tests were applied to the results obtained at a level of significance of 5%. RESULTS: The results demonstrated that the Sealer Plus sealer showed a lower radiopacity value than AH Plus sealer (P < .05); however, this was higher than the minimum value recommended by the specifications (ie, 3 mm Al). Relative to flow, the value for Sealer Plus was 19.19 mm and for AH Plus, 19.81 mm (P > .05). Sealer Plus presented initial and final setting times of 138 minutes and 210 minutes, respectively, whereas the values for AH Plus were 437 minutes and 849 minutes, respectively (P < .05). Relative to solubility, Sealer Plus presented 0.21% and AH Plus, 0.27% (P > .05). None of the sealers showed a significant increase in pH (P > .05). CONCLUSIONS: Sealer Plus sealer presented physicochemical properties in accordance with American National Standards Institute/American Dental Association (2000) No. 57 and International Organization for Standardization 6876 (2012) specifications.


Asunto(s)
Hidróxido de Calcio/química , Resinas Epoxi/química , Materiales de Obturación del Conducto Radicular/química , Fenómenos Químicos , Ensayo de Materiales
19.
Braz. oral res. (Online) ; 32: e88, 2018. tab, graf
Artículo en Inglés | LILACS-Express | ID: biblio-952167

RESUMEN

Abstract The aim of this study was to evaluate the influence of a novel ultrasonic tip as an auxiliary method for removing filling material from flattened/oval-shaped canals. The null hypothesis tested was that this method does not influence removing the filling material in flattened/oval-shaped canals. Forty-five mandibular incisors were selected and randomly divided into three experimental groups (n = 15) according to different protocols for removing root canal filling material. Group R: Reciproc R25/.08, Group RC: Reciproc R25/.08 + Clearsonic tip, and Group CR: Clearsonic tip + Reciproc R25/.08. The teeth were scanned pre and post-operatively by means of a micro-computed tomography system. Data were analyzed using non-parametric Kruskal-Wallis and Dunn tests (p < 0.05). The percentage of residual root canal filling material between the experimental groups was examined. Statistically significant differences between the experimental groups were found in the root canal. Group R had the highest percentage of residual root canal filling material when compared with Groups RC and CR. The lowest percentage of residual root canal filling material was observed in Group CR. In the apical third of the root canal, statistically significant differences were found between the different protocols. The use of the ClearSonic tip followed by the Reciproc 25/.08 file to remove filling material resulted in the lowest percentage of residuals in the whole root canal and in the apical third.

20.
J Appl Oral Sci ; 25(6): 641-649, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29211285

RESUMEN

MATERIAL AND METHODS: The aim of this study was evaluate the influence of ultrasonic activation (UA) of AH Plus to improve canal and isthmus filing, and analyse the antimicrobial effect against Enterococcus faecalis within dentinal tubules. Thirty mesial roots of mandibular first molars were selected and divided into 2 groups (n = 15): with and without UA of the sealer. Then the root canals were filled by using the single cone technique, and the specimens were sectioned at 2, 4 and 6 mm from the apex for stereomicroscope and confocal laser scanner microscopy (CLSM) analysis. In addition, 30 bovine incisors were contaminated with Enterococcus faecalis and divided into 3 groups (n = 10). The specimens were obturated by using the single cone technique with (G1) and without (G2) UA of the sealer and G3 as the control group. All were sectioned into 6 mm-long cylinders and stained with LIVE/DEAD to assess bacterial viability by CLSM. RESULTS: The UA of the sealer significantly reduced the presence of unfilled areas in the canal and isthmus area in all sections (p<0.05), and there was a significant increase in sealer penetration in both canals and isthmuses (p<0.05). As regards gaps, a significant reduction was found at 2 and 6 mm in the isthmus area of the UA group (p<0.05). Moreover, UA of the sealer significantly reduced bacterial viability in the superficial dentine when compared with the other groups (p<0.05). CONCLUSION: Ultrasonic activation of the AH Plus sealer promoted a better quality of root canal filling and increased the intratubular penetration of sealer, especially in the isthmus area. Additionally, ultrasonic activation of the sealer increased the intradentinal antimicrobial action against Enterococcus faecalis, mainly in the superficial dentine of the root canal.


Asunto(s)
Cavidad Pulpar/microbiología , Enterococcus faecalis/efectos de los fármacos , Resinas Epoxi , Materiales de Obturación del Conducto Radicular/farmacología , Obturación del Conducto Radicular/métodos , Ultrasonido , Humanos , Microscopía Confocal
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