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1.
Braz. oral res. (Online) ; 30(1): e1, 2016. tab, graf
Article in English | LILACS | ID: lil-768263

ABSTRACT

This study evaluates the effect of two thermoplastic obturation systems (MicroSeal and Obtura II) on bond strength of different sealers to intraradicular dentin. Sixty root canals of human canines were prepared using ProTaper rotary files (crown-down technique) and irrigated with 2.5% sodium hypochlorite and 17% EDTA. The root canals were filled by MicroSeal, Obtura II, or lateral compaction techniques using AH Plus and Epiphany SE. 1.5 mm thick root slices were subjected to the push-out test. ANOVA and Tukey's test showed that the bond strength values (MPa) observed in the groups obturated with MicroSeal (2.96 ± 2.72) and Obtura II (2.68 ± 2.18) did not significantly differ from each other (p > 0.05) but were significantly higher than that observed in the group obturated with lateral condensation (2.01 ± 1.48; p < 0.05). There were no statistically significant differences in strength (p > 0.05) among the root canal thirds (cervical: 2.44 ± 2.03; middle: 2.50 ± 2.27; and apical: 2.70 ± 2.34). Adhesive failures were predominant (60%) in all groups. In conclusion, MicroSeal and Obtura II techniques, using AH plus sealer, increased the resistance to displacement of the filling material, when compared with lateral compaction. Moreover, when used with Epiphany SE, these obturation systems did not affect the bond strength of the material to root dentin.


Subject(s)
Humans , Dental Bonding/methods , Epoxy Resins/chemistry , Root Canal Filling Materials/chemistry , Root Canal Obturation/methods , Analysis of Variance , Dental Restoration Failure , Dentin/drug effects , Gutta-Percha/chemistry , Materials Testing , Reproducibility of Results , Statistics, Nonparametric
2.
Braz. oral res. (Online) ; 30(1): e27, 2016. tab, graf
Article in English | LILACS | ID: biblio-952023

ABSTRACT

Abstract The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm3) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = ٠.٠٥). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique.


Subject(s)
Humans , Root Canal Filling Materials/chemistry , Bismuth/chemistry , Calcium Hydroxide/chemistry , Salicylates/chemistry , Root Canal Preparation/methods , Epoxy Resins/chemistry , X-Ray Microtomography/methods , Materials Testing , Random Allocation , Reproducibility of Results , Statistics, Nonparametric , Imaging, Three-Dimensional , Gutta-Percha/chemistry
3.
Braz. dent. j ; 24(4): 367-370, July-Aug/2013. tab, graf
Article in English | LILACS | ID: lil-689839

ABSTRACT

This study used micro-computed tomography (micro-CT) to evaluate the fit of the master gutta-percha cone at time of cone fit, gutta-percha volume in the filling material, and the filling material volume in relation to the canal at the apical limit of the working length. Root canals of 20 maxillary central incisors were prepared with rotary instruments and distributed into two groups (n=10). The gutta-percha cone tip was either plasticized (apical thermal impression technique - ATI) or not (conventional technique - CT), and its apical fit was checked. The apical 1 mm of working length was examined with a micro-CT, canals were filled with gutta-percha and sealer, and new micro-CT scans were obtained. In CT, gutta-percha filled 35.83 ± 15.05% of the canal at cone selection and 38.72 ± 11.64% after filling. In ATI, these values were 23.14 ± 7.74% and 26.98 ± 20.40%, respectively. Gutta-percha volume in the filling material, and filling material volume in relation to the canal were, respectively, 61.28 ± 11.64% and 87.76 ± 9.98% for CT, and 73.00 ± 20.41% and 89.96 ± 9.08% for ATI. No significant difference was found between cone selection and after canal filling, for either CT (p=0.593) or ATI (p=0.4975). The techniques did not differ significantly with respect to gutta-percha volume in the filling material (p=0.132) and filling material volume in relation to the canal (p=0.612). An ideal fit of the master gutta-percha cone at working length was not achieved regardless of the cone selection technique, and the material-filled area was similar for both techniques.


Este estudo utilizou microtomografia computadorizada (micro-CT) para avaliar a adaptação do cone de guta-percha no momento da sua seleção, o volume de guta-percha no material obturador, e o volume do material obturador em relação ao canal no limite apical do comprimento de trabalho. Canais radiculares de 20 incisivos centrais superiores foram preparados com instrumentos rotatórios e distribuídos em dois grupos (n=10). A ponta do cone de guta-percha foi plastificada (técnica de impressão térmica apical - TIT) ou não (técnica convencional - TC), e seu ajuste apical foi verificado. O milimetro apical do comprimento de trabalho foi examinado em micro-CT, os canais foram preenchidos com guta-percha e cimento, e novas imagens em micro-CT foram obtidas. Na TC, a guta-percha preencheu 35,83 ± 15,05% do canal no momento da seleção do cone e 38,72 ± 11,64% após a obturação. Na TIT, estes valores foram de 23,14 ± 7,74% e 26,98 ± 20,40%, respectivamente. O volume de guta-percha no material obturador, e o volume do material obturador em relação ao canal, foram, respectivamente, 61,28 ± 11,64% e 87,76 ± 9,98% para a TC, e 73,00 ± 20,41% e 89,96 ± 9,08% para TIT. Não foi encontrada diferença significativa entre a seleção do cone e depois o preenchimento do canal para ambas as técnicas, TC (p =0,593) ou TIT (p=0,4975). As técnicas não diferiram significativamente com respeito ao volume de guta-percha no material obturador (p=0,132), e volume de preenchimento de material em relação ao canal (p=0,612). Um ajuste ideal do cone principal de guta-percha cone no seu comprimento de trabalho não foi alcançado, independentemente da técnica de seleção empregada, e a area preenchida pelo material obturador foi semelhante para ambas as técnicas.


Subject(s)
Humans , Gutta-Percha , X-Ray Microtomography/methods
4.
RSBO (Impr.) ; 9(4): 282-287, Oct.-Dec. 2012. ilus, tab
Article in English | LILACS-Express | LILACS | ID: lil-755714

ABSTRACT

Introduction and objective: The aim of this study was to assess the surface and the substrate/glass ionomer cement (GIC) interface after Er:YAG laser irradiation by means of scanning electron microcopy. Material and methods: Thirty human third molars were selected and had their roots removed. Crowns were sectioned to obtain discs that were randomly assigned to three groups according to the surface pretreatment: 40% polyacrylic acid (control); Er:YAG laser irradiation (80mJ/2Hz) or Er:YAG laser followed by 40% polyacrylic acid. Two discs of each group were put aside to the surface analysis and the others were bisected. One half received Ketac-Fil and the other received Fuji II LC. Specimens were prepared for SEM and were analyzed under different magnifications. Results: Er:YAG laser group showed no adhesive interface for both enamel and dentin, but strongly damaged the interface build-up for dentin/Fuji II LC. The application of laser irradiation followed by the polyacrylic acid exhibited gaps and irregularities for both substrates. Conclusion: Er:YAG laser irradiation combined or not with 40% polyacrylic acid produced a surface unfavorable for GIC interaction, especially for the resin-modified ones.

5.
RSBO (Impr.) ; 9(3): 280-285, Jul.-Sep. 2012. ilus, tab
Article in English | LILACS-Express | LILACS | ID: lil-748126

ABSTRACT

Introduction: The use of adhesive composite resin with fluoride and with greater fluidity can be favorable to the restoration of the palatal/lingual face of teeth submitted to internal bleaching. Objective: This study evaluated the bond strength of adhesive systems and composite resins to bleached dentin. Material and methods:Forty maxillary canines were sectioned to obtain 40 blocks (5 x 5 mm) of intracoronary dentin. The fragments were included and bleached with 37% carbamide peroxide. After 7 days, the specimens were divided into two groups according to the adhesive system: with (Optibond Solo Plus) and without (Single Bond) fluoride and subdivided into 2 subgroups (n = 10) according to the composite resin: microhybrid (Z250) and flowable (Z350). The restoration was carried out through a bipartite matrix. After 24 hours, the specimens were subjected to shear bond strength test. The data (MPa) were analyzed by ANOVA and Tukey test (a = 0.05). Results: The best results (p < 0.05) were obtained for fluoridated adhesive (7.44 ± 2.35) compared with that without fluoride (5.36 ± 2.01); flowable resin (7.76 ± 2.23) performed better than microhybrid resin (5.03 ± 1.72). When the two variables were associated, the highest results were obtained for the specimens restored with fluoridated adhesive and flowable resin (9.04 ± 1.92). Lower results were observed for non-fluoridated adhesive + microhybrid resin - control (4.24 ± 1.59), without statistically significant differences when compared with the fluoridated adhesive + microhybrid resin (5.83 ± 1.52). Conclusion: The combination with fluoridated adhesive and flowable resin increases the shear bond strength of bleached dentin.

6.
RSBO (Impr.) ; 9(3): 292-297, Jul.-Sep. 2012.
Article in English | LILACS-Express | LILACS | ID: lil-748127

ABSTRACT

Introduction: The bonding of dental posts to the root canal walls depends on the resin cement Objective:This in vitro study assessed the bond strength of resin cements used for post cementation to different root regions. Material and methods: Thirty canine roots were endodontically treated and prepared to receive dental posts which were luted with different resin cements (n = 10): Enforce (Dentsply), Panavia F (Kuraray Dental Co) and RelyX ARC (3M ESPE). The cements were light-cured for 20 s. After cementation, slices from cervical, middle and apical post/root regions were submitted to the push out test in a universal testing machine. The data (MPa) were analyzed using ANOVA and Tukey’s test (a = 0.05). Results: RelyX ARC (3.24 ± 1.49) and Enforce (3.45 ± 1.42) showed higher bond strength than Panavia (0.95 ± 0.39) (p < 0.05), without statistically significant difference between each other (p > 0.05). The bond strength values at the cervical (3.37 ± 1.47) were higher than middle (2.62 ± 1.94) and apical (1.65 ± 0.99) regions (p < 0.05), which were similar between them (p > 0.05). Conclusion: The resin cements RelyX ARC and Enforce presented greater bond strength than Panavia and the bond strength was higher at the cervical region.

7.
RSBO (Impr.) ; 9(3): 298-302, Jul.-Sep. 2012. tab
Article in Spanish | LILACS-Express | LILACS | ID: lil-748128

ABSTRACT

Introduction: The aim of this study was to evaluate in vitro the bonding of AH Plus and Endofill sealers to intraradicular canal walls after different dentin surface treatments. Material and methods: Sixty canines were sectioned obtaining dentin discs with 4-mm thickness and were embedded in acrylic resin. The canals were prepared with diamond burs. The specimens were divided into two groups (n = 30): GI - AH Plus and GII - Endofill and were subdivided into three groups based on the dentin surface treatment (n = 10): A - distilled and deionized water (control), B - 17% EDTA, C - CO2 laser with 3W in continuous mode for 10s. The specimens were submitted to push out test in a universal testing machine. Results: Tukey test revealed that the IB (AH Plus/17% EDTA) (17.59 ± 6.04) and IC (AH Plus/CO2 laser) (21.69 ± 4.93) subgroups had the highest values, which were statistically similar between each other (p > 0.05) and different from the other subgroups (p < 0.05). IIC subgroup (Endofill/CO2 laser) (7.25 ± 1.59) had intermediate values, which were statistically similar to (p > 0.05) IA subgroup (AH Plus/water) (10.99 ± 2.63), IIA subgroup (Endofill/water) (3.16 ± 0.83) and IIB subgroup (Endofill/ 17% EDTA) (5.31 ± 3.61), which had the smallest values (p < 0.05). Conclusion: The treatment of superficial intracanal dentin with CO2 laser and EDTA favored the adhesion of AH Plus and Endofill sealers.

8.
RSBO (Impr.) ; 9(3): 303-308, Jul.-Sep. 2012. tab
Article in English | LILACS-Express | LILACS | ID: lil-748129

ABSTRACT

Introduction: The bond strength of dentin bleached with high concentrated agents can be reestablished if the appropriate restorative material is selected. Objective:The aim of this study was to evaluate the influence of bleaching agents and adhesive system on bond strength of restorative material to intracoronary dentin. Material and methods: 60 fragments of intracoronary dentin (25 mm2) were embedded in acrylic resin and divided into 3 groups (n = 10): GI - not bleached (control), GII - 35% hydrogen peroxide (35HP), GIII - 38% hydrogen peroxide (38HP). The gel was applied for 10 min onto the dentin surface. This protocol was repeated three times at a single session. After 14 days, the groups were divided into subgroups according to the adhesive system used in the restoration: A - Self-etching (Clearfil SE Bond) and B - Total etching (Single Bond 2). The fragments were restored with Z100 Filtek resin using a bipartite matrix. After 24 h, the specimens were subjected to shear bond strength test. Data were analyzed by two-way ANOVA and Tukey test (p < 0.05). Results: The group bleached with 38HP (6.02 ± 3.95) had the highest bond strength to dentin, followed by 35HP (5.36 ± 3.54), and control group (3.11 ± 2.71) (p < 0.05), although without statistically significant differences. It was also verified a higher bond strength in the group restored with the self-etching adhesive system (6.60 ± 4.18) when compared to the total etching system (3.06 ± 1.57). Conclusion: When performing the restoration of teeth bleached with hydrogen peroxide at high concentrations (35% and 38%), self-etching adhesive system should be the first choice.

9.
RSBO (Impr.) ; 9(3): 328-333, Jul.-Sep. 2012. ilus
Article in Portuguese | LILACS-Express | LILACS | ID: lil-748133

ABSTRACT

Introduction: Traumatic injuries are usually the result of impacts whose aggressive strength exceeds the resistance found in bone, muscle and tooth tissues. With the advent of the etching technique and considering the improvement of composite resins, simpler and more conservative alternatives are indicated in the aesthetic and functional rehabilitation of fractured anterior teeth. Report and Objective: This study aimed to report the treatment of a 13 year-old patient that fractured his central incisor due to a trauma. After clinical and radiographic examination, an oblique crown fracture with extensive involvement of the incisal angle, without pulp exposure or injury to the biological space of the left maxillary central incisor (tooth #21) was observed. Because the fractured tooth fragment was lost, it was not possible to process a fragment bonding. Thus, it was proposed to treat the tooth through direct technique restoration with composite resin. Conclusion: It can be concluded that the aesthetic and functional rehabilitation with direct composite resin is a viable option for the conservative treatment of fractured anterior teeth.

10.
Braz. dent. j ; 23(6): 679-685, 2012. ilus, tab
Article in English | LILACS | ID: lil-662426

ABSTRACT

The aim of this study was to assess the influence of surface pretreatments of fiber-reinforced posts on flexural strength (FS), modulus of elasticity (ME) and morphology of these posts, as well as the bond strength (BS) between posts and core material. Fifty-two fiber posts (smooth and serrated) were assigned to 4 groups (n=13): no treatment (control), 10% hydrogen peroxide (HP) for 10 min (HP-10), 24% HP for 1 min (HP-24) and airborne-particle abrasion (Al2O3). To evaluate FS and ME, a 3-point bending test was performed. Three posts of each group were examined by scanning electron microscopy. Composite resin was used as the core build-up and samples were sectioned to obtain microtensile sticks. Data were analyzed by ANOVA and Tukey's test (α=0.05). For FS, significant differences were observed between posts type and surface pretreatment (p<0.05), with the highest means for the smooth posts. Al2O3 provided higher FS than HP-24. Al2O3 promoted higher ME than HP-24 and control. SEM images revealed partial dissolution of the resin matrix in all treated groups. The smooth posts had higher BS and FS than serrated posts (p<0.05). Mechanical properties of the glass fiber posts and the bond strength between posts and composite material were not altered by the surface treatments, except for airborne-particle abrasion that increased the post elastic modulus.


O objetivo deste estudo foi avaliar a influência do pré-tratamento de superfície dos pinos de fibra de vidro na resistência à flexão (RF), módulo de elasticidade (ME) e morfologia, bem como a resistência de união (RU) entre os pinos e o núcleo de preenchimento. Cinqüenta e dois pinos de fibra de vidro (lisos e serrilhados) foram divididos em 4 grupos (n=13): sem tratamento (controle), peróxido de hidrogênio a 10% por 10 min (HP-10), peróxido de hidrogênio 24% por 1 min (HP-24) e jato de óxido de alumínio (Al2O3). Para avaliar a RF e ME, o ensaio de flexão de 3 pontos foi realizado. Três pinos de cada grupo foram examinados em MEV. Resina composta foi utilizada como núcleo de preenchimento e as amostras foram seccionadas para obter palitos de microtração. Os dados foram analisados por ANOVA e teste de Tukey (α=0,05). Na RF, observou-se diferença estatisticamente significante entre os pinos e tipo de pré-tratamento de superfície (p<0,05), com as maiores médias para os pinos lisos. Al2O3 proporcionou maior RF que HP-24. Al2O3 promoveu maior ME que HP-24 e grupo controle. MEV revelou dissolução parcial da matriz de resina em todos os grupos tratados. Os pinos lisos tiveram a maior RU (p<0,05). Os pinos lisos apresentaram RF e RU superior aos pinos serrilhados (p<0,05). As propriedades mecânicas dos pinos de fibra de vidro e a resistência de união entre os pinos e o material resinoso não foram alterados pelos tratamentos de superfície, com exceção do jato de óxido de alumínio que aumentou o módulo de elasticidade dos pinos.


Subject(s)
Humans , Dental Bonding , Dental Etching/methods , Dental Materials/chemistry , Glass/chemistry , Post and Core Technique/instrumentation , Aluminum Oxide/chemistry , Composite Resins/chemistry , Dental Prosthesis Design , Dental Stress Analysis/instrumentation , Elastic Modulus , Epoxy Resins/chemistry , Hydrogen Peroxide/chemistry , Materials Testing , Microscopy, Electron, Scanning , Oxidants/chemistry , Pliability , Solubility , Stress, Mechanical , Surface Properties , Silanes/chemistry , Temperature , Tensile Strength , Time Factors , Water/chemistry
11.
Braz. dent. j ; 23(1): 28-35, 2012. ilus, tab
Article in English | LILACS | ID: lil-618001

ABSTRACT

This study evaluated the effect of bleaching agents on bond strength at the dentin/resin interface and the flexural strength of dentin. Forty maxillary canines were selected for the study. In the shear strength test, 40 slabs of intracoronary dentin (5 x 5 mm) obtained from buccal surfaces of the crowns were included in acrylic resin. In the flexural strength test, 40 dentin bars (8 x 2 x 2 mm) were obtained from the roots. The 40 hemi-sections of the lingual surface were prepared for scanning electron microscopy (SEM). The specimens were divided into 4 groups according to the bleaching protocol (n=10): Unbleached (control), Sodium perborate + 20 percent hydrogen peroxide (SP + 20 percent HP), 37 percent carbamide peroxide (37 percent CP) and 38 percent hydrogen peroxide (38 percent HP). After 7 days, the bond strength specimens were restored and tested. Dentin bars were bleached and subjected to a three-point bending test. Data (MPa) were analyzed by ANOVA and Tukey's test (α=0.05). In the shear test, the control group was superior (p<0.05) to the bleached groups, which, in turn, were statistically similar (p>0.05). In the flexural strength test, the control group also had the highest values and differed significantly from the other groups (p<0.05). SEM revealed smear layer in all groups, with fissures in the bleached specimens. SP + 20 percent HP and 38 percent HP showed discontinuous interfaces with few tags. In conclusion, bond strength of restorative material to dentin and flexural strength of dentin were reduced after the use of high-concentration bleaching agents.


Este estudo avaliou o efeito de agentes clareadores na resistência de união da interface dentina/resina e resistência à flexão da dentina. Quarenta caninos superiores foram selecionados para o estudo. No teste de cisalhamento, 40 fragmentos de dentina intracoronária (5 x 5 mm) obtidos a partir de superfícies vestibulares das coroas foram incluídos em resina acrílica. No teste de flexão, 40 barras de dentina (8 x 2 x 2 mm) foram obtidas a partir das raízes. As 40 hemi-seções da superfície lingual foram preparadas para microscopia eletrônica de varredura (MEV). Os espécimes foram divididos em 4 grupos de acordo com o protocolo de clareamento (n=10): Não clareados (controle), perborato de sódio + peróxido de hidrogênio 20 por cento (PS + PH 20 por cento), peróxido de carbamida 37 por cento (PC37 por cento) e peróxido de hidrogênio 38 por cento (PH 38 por cento). Após 7 dias, as amostras destinadas à resistência de união foram restauradas e submetidas ao teste. As barras de dentina foram clareadas e submetidas ao teste de flexão de 3 pontos. Os dados (MPa) foram analisados por ANOVA e teste de Tukey (α=0,05). No teste de cisalhamento, o controle foi superior (p<0,05) aos grupos clareados, que foram semelhantes entre si (p>0,05). Na resistência à flexão, o grupo controle também exibiu os maiores valores, diferente dos demais (p<0,05). SEM revelou camada de smear em todos os grupos, com fissuras nos espécimes clareados. PS + 20 por cento PH e PH 38 por cento apresentaram interfaces de descontínuas com poucos tags. A resistência de união do material restaurador à dentina e a resistência à flexão da dentina foram reduzidas após o uso de agentes clareadores de alta concentração.


Subject(s)
Humans , Composite Resins/chemistry , Dental Stress Analysis , Dental Enamel/drug effects , Dentin-Bonding Agents/chemistry , Dentin/drug effects , Tooth Bleaching/adverse effects , Adhesiveness , Analysis of Variance , Bleaching Agents/adverse effects , Bleaching Agents/chemistry , Dentin/chemistry , Incisor , Maxilla , Microscopy, Electron, Scanning
12.
Braz. dent. j ; 22(5): 382-387, 2011. ilus, tab
Article in English | LILACS | ID: lil-601838

ABSTRACT

This study evaluated the effect of 980-nm diode laser on apical microleakage and intraradicular dentin morphology. Roots of 110 mandibular incisors were used in the study: 92 for microleakage test and 18 for scanning electron microscopy (SEM). Roots were randomly assigned to 3 groups according to the irrigating solution (water, NaOCl and NaOCl/EDTA) and were divided into 3 subgroups according to the laser irradiation protocol (without irradiation, irradiated at 1.5 W and irradiated at 3.0 W). Two specimens of each subgroup were prepared for SEM. The remaining roots were filled with AH Plus and gutta-percha. Apical leakage was assessed by ink penetration and data were analyzed statistically by ANOVA and Tukey-Krammer test (α=0.05). SEM analysis showed intensification of changes with increase of laser power as well as variations according to the irrigating solution. Modified smear layer was observed in specimens treated with water and irradiated with laser. Roots irrigated with NaOCl/EDTA had lower levels of infiltration (0.17 ± 0.18 mm) differing significantly (p<0.05) from those of roots irrigated with water (0.34 ± 0.30 mm), but similar (p>0.05) to those irrigated with NaOCl (0.28 ± 0.29 mm). Non-irradiated roots had lower levels of infiltration (0.10 ± 0.14 mm), differing (p<0.05) from those irradiated at 1.5 W (0.32 ± 0.22 mm) and 3.0 W (0.37 ± 0.32 mm). The 980 nm diode laser modified dentin morphology and increased apical microleakage.


Este estudo avaliou o efeito do laser de diodo 980 nm na microinfiltração apical e na morfologia intrarradicular da dentina. Raízes de 110 incisivos inferiores foram utilizadas no estudo: 92 para o teste de microinfiltração e 18 para microscopia eletrônica de varredura (MEV). As raízes foram divididas em 3 grupos de acordo com a solução irrigante (água, NaOCl e NaOCl/EDTA) e subdivididas em 3 de acordo com a irradiação laser (sem irradiação, irradiados com 1,5 W e irradiados com 3,0 W). Duas amostras de cada subgrupo foram preparadas para MEV. As raízes restantes foram preenchidas com AH Plus e guta percha. A infiltração apical foi avaliada nas raízes por meio da penetração do corante e os dados foram analisados por ANOVA e teste de Tukey-Krammer (α=0,05). Os resultados da MEV mostraram intensificação das mudanças quando se aumentou a potência do laser e variações de acordo com a solução irrigadora. Camada de smear modificada foi observada em espécimes tratados com água e irradiados com laser. Raízes irrigadas com NaOCl/EDTA tiveram níveis menores de infiltração (0,17 ± 0,18 mm) estatisticamente diferente (p<0,05) das raízes irrigadas com água (0,34 ± 0,30 mm), mas semelhante (p>0,05) aos irrigados com NaOCl (0,28 ± 0,29 mm). As raízes não irradiadas tiveram níveis menores de infiltração (0,10 ± 0,14 mm), diferente (p<0,05) de 1,5 W (0,32 ± 0,22 mm) e 3.0 W (0,37 ± 0,32 mm). O laser de diodo 980 nm alterou a morfologia da dentina e aumentou a infiltração marginal apical.


Subject(s)
Humans , Dental Leakage/classification , Dental Pulp Cavity/radiation effects , Dentin/radiation effects , Lasers, Semiconductor/therapeutic use , Tooth Apex/radiation effects , Coloring Agents , Cuspid/radiation effects , Cuspid/ultrastructure , Dental Bonding , Dental Pulp Cavity/ultrastructure , Dentin/ultrastructure , Edetic Acid/therapeutic use , Epoxy Resins/therapeutic use , Gutta-Percha/therapeutic use , Incisor/radiation effects , Incisor/ultrastructure , Materials Testing , Microscopy, Electron, Scanning , Radiation Dosage , Root Canal Filling Materials/therapeutic use , Root Canal Irrigants/therapeutic use , Root Canal Preparation/methods , Smear Layer , Sodium Hypochlorite/therapeutic use , Tooth Apex/ultrastructure , Water
13.
Braz. dent. j ; 22(1): 32-36, 2011. tab
Article in English | LILACS | ID: lil-582398

ABSTRACT

This study evaluated the influence of bleaching protocols on intrapulpal temperature and fracture strength of the bleached teeth. Ninety maxillary incisors were assigned to 9 groups (n=10): G1: 35 percent carbamide peroxide (35 percent CP), G2: 38 percent hydrogen peroxide (38 percent HP), G3: halogen light, G4: LED-laser, G5: 35 percent CP + halogen light, G6: 38 percent HP + halogen light, G7: 35 percent CP + LED-laser, G8: 38 percent HP + LED-laser, and G9: no treatment (control). Pulp space was widened, a thermocouple was introduced through the apex up to the pulp chamber and the temperature was recorded (°C). The fracture strength (kN) was determined using an Instron machine. Data were analyzed by ANOVA and Tukey's test (p<0.05). The halogen light alone (1.10 ± 0.24) (G3) and associated with 38 percent HP (1.15 ± 0.30) (G6) produced the highest temperature increase, statistically different (p<0.05) from the other groups. G1 (0.15 ± 0.06) and G6 (0.19 ± 0.07) produced the lowest values, statistically different (p<0.05) from G5 (0.65 ± 0.49). The bleaching protocols increased the temperature, but no increment exceeded the critical value of 5.6°C. Neither 35 percent CP nor 38 percent HP or the light sources alone altered the fracture strength of the teeth.


Este estudo avaliou a influência de protocolos de clareamento na temperatura intrapulpar e resistência à fratura de dentes clareados. Noventa incisivos superiores foram divididos em 9 grupos (n=10): G1: peróxido de carbamida a 35 por cento (PC 35 por cento), G2: peróxido de hidrogênio a 38 por cento (PH 38 por cento), G3: luz halógena, G4: LED-laser, G5: PC 35 por cento + luz halógena, G6: PH 38 por cento + luz halógena, G7: PC 35 por cento + LED-laser, G8: PH 38 por cento + LED-laser e G9: sem tratamento (controle). O canal radicular foi alargado, um termopar foi introduzido no ápice até a câmara pulpar e a temperatura foi calculada (°C). A resistência à fratura (kN) foi determinada em máquina Instron. Os dados foram analisados por análise de variância e teste de Tukey (p>0,05). A luz halógena utilizada isoladamente (1,10 ± 0,24) (G3) e associada ao PH 38 por cento (1,15 ± 0,30) (G6) proporcionaram os maiores valores de temperatura, sendo estatisticamente diferentes dos demais grupos (p<0,05). O G1 (0,15 ± 0,06) e o G6 (0,19 ± 0,07) produziram os menores valores de resistência à fratura, sendo estatisticamente diferentes (p<0,05) do G5 (0,65 ± 0,49). Os protocolos de clareamento aumentaram a temperatura, mas nenhum incremento excedeu o valor crítico de 5,6oC. O PC 35 por cento, PH 38 por cento e as fontes de luz utilizadas isoladamente não alteraram a resistência à fratura dos dentes.


Subject(s)
Humans , Body Temperature/drug effects , Dental Pulp/drug effects , Tooth Bleaching Agents/administration & dosage , Tooth Bleaching/methods , Tooth Fractures/prevention & control , Curing Lights, Dental , Dental Stress Analysis , Dental Pulp/physiology , Hydrogen Peroxide/administration & dosage , Incisor/drug effects , Lasers, Semiconductor , Maxilla , Peroxides/administration & dosage , Tooth Bleaching Agents/adverse effects , Tooth Bleaching/adverse effects , Tooth Fractures/etiology , Urea/administration & dosage , Urea/analogs & derivatives
14.
Braz. dent. j ; 22(2): 117-121, 2011. tab
Article in English | LILACS | ID: lil-583799

ABSTRACT

This study evaluated the fracture resistance of teeth submitted to internal bleaching and restored with different procedures. Forty maxillary incisors were endodontically treated and assigned to 4 groups (n=10): G1- restored with composite resin (CR), G2- bleached with hydrogen peroxide (HP) and restored with CR, G3- restored with CR and fiberglass posts (CR + posts) and G4- bleached and restored with CR + posts. HP was applied in the buccal surface and pulp chamber 3 times at each one of 2 sessions with an interval of 7 days between them. Additional 10 sound incisors were subjected to fracture strength test (gold standard). The fracture strength (kN) was determined in an Instron machine. Data were analyzed by ANOVA and Tukey-Kramer test (α=0.05). The untreated teeth (gold standard) showed the highest (p<0.05) fracture strength (0.43 ± 0.16). Teeth restored with CR (G1) without internal bleaching had the lowest (p<0.05) fracture strength (0.23 ± 0.11). Teeth bleached and restored with CR (G2) (0.26 ± 0.10), restored with CR + posts ithout internal bleaching (G3) (0.31 ± 0.17) and, bleached and restored with CR + posts (G4) (0.33 ± 0.12) had intermediate values, sometimes similar to the group with the highest value, sometimes similar to the group with the lowest value. In conclusion, as far as the fracture strength is concerned, teeth subjected to internal bleaching can be restored with composite resin alone, as the use of posts in these teeth did not increase their resistance.


Este estudo avaliou a resistência à fratura de dentes submetidos ao clareamento interno restaurados com diferentes procedimentos. Quarenta incisivos superiores foram tratados endodonticamente e divididos em 4 grupos (n = 10): G1- restaurados com resina composta (RC), G2- clareados com peróxido de hidrogênio (PH) e restaurados com o RC, G3- restaurado com RC e pinos de fibra de vidro (RC + pinos) e G4- clareados e restaurados com RC + pinos. O PH foi aplicado na superfície vestibular e câmara pulpar 3 vezes por sessão, por 2 sessões com intervalo de 7 dias entre elas. Dez dentes hígidos adicionais foram submetidos a teste fratura (padrão ouro). A resistência à fratura (kN) foi determinada em máquina Instron. Os dados foram analisados por Análise de Variânica e teste de Tukey-Krammer (α= 0,05). Os dentes não tratados (padrão ouro) apresentaram a maior resistência à fratura (0,43 ± 0,16) (p <0,05). Os dentes restaurados com RC (G1) apresentaram a menor resistência à fratura (0,23 ± 0,11) (p <0,05). Os dentes clareados e restaurados com RC (G2) (0,26 ± 0,10), restaurado com RC + pinos (G3) (0,31 ± 0,17) e os clareados e restaurados com RC + pinos (G4) (0,33 ± 0,12) apresentaram valores intermediários, ora semelhantes ao do grupo com o maior valor, ora similares ao grupo de valores mais baixos. Pode-se concluir que os dentes submetidos ao clareamento interno podem ser restaurados com apenas resina composta.


Subject(s)
Humans , Dental Restoration, Permanent/methods , Post and Core Technique , Tooth Bleaching/methods , Tooth Fractures/prevention & control , Tooth, Nonvital/physiopathology , Analysis of Variance , Composite Resins , Dental Restoration Failure , Dental Stress Analysis , Glass , Hydrogen Peroxide/administration & dosage , Statistics, Nonparametric , Tooth Bleaching Agents/administration & dosage , Tooth Fractures/etiology
15.
Braz. dent. j ; 22(4): 317-321, 2011. tab
Article in English | LILACS | ID: lil-595663

ABSTRACT

This study assessed the effect of bleaching protocols with 38 percent hydrogen peroxide (HP) and post-bleaching times on shear bond strength of a composite resin to dentin. One-hundred slabs of intracoronary dentin were included and randomly assigned into 2 groups according to the bleaching protocol: HP (2 applications of 10 min each) and HP activated by LED laser (2 applications of 10 min each/45 s of light activation). Groups were subdivided according to the post-bleaching time (n=10): 1 day, 3 days, 7 days, 10 days and 14 days. The control group was unbleached and restored (n=10). The specimens were restored with Single Bond adhesive system/Filtek Z250 resin using a polytetrafluorethylene matrix and were submitted to the shear bond strength testa after 24 h,. Data were analyzed by ANOVA and Tukey's test (α=0.05). Unbleached group (0.283 ± 0.134) had the highest bond strength and was statistically similar (p>0.05) to HP/10 days (0.278 ± 0.064), HP + LED laser/10 days (0.280 ± 0.078), HP/14 days (0.281 ± 0.104), HP + LED laser/14 days (0.277 ± 0.093). Lower bond strength were verified in HP/1 day (0.082 ± 0.012), HP/3 days (0.079 ± 0.013), HP + LED laser/1 day (0.073 ± 0.018) and HP + LED laser/3 days (0.080 ± 0.015), which were statistically similar (p>0.05). HP/7 days (0.184 ± 0.154) and HP + LED laser/7 days (0.169 ± 0.102) had intermediate values (p<0.05). The restorative procedure of intracoronary dentin bleached with 38 percent HP with or without the use of light source should be performed after at least 10 days after the bleaching treatment.


Este estudo avaliou o efeito de protocolos de clareamento com peróxido de hidrogênio 38 por cento (PH) e tempos pós-clareamento na resistência ao cisalhamento de uma resina composta á dentina. Cem fragmentos de dentina intracoronária foram incluídos e distribuídos aleatoriamente em 2 grupos experimentais de acordo com o protocolo de clareamento: PH (2 aplicações de 10 min cada) e HP ativado por LED laser (2 aplicações de 10 min cada/45 s de ativação pela luz). Os grupos foram subdivididos de acordo com o tempo pós-clareamento (n=10): 1 dia, 3 dias, 7 dias, 10 dias e 14 dias. O grupo controle não foi clareado e apenas restaurado (n=10). Os espécimes foram restaurados com sistema adesivo Single Bond/resina Filtek Z250 usando matriz de teflon. Após 24 h, foram submetidos ao teste de cisalhamento. Os dados foram analisados por ANOVA e teste de Tukey (α=0,05). O grupo não clareado (0,283 ± 0,134) apresentou a maior resistência de união e foi estatisticamente semelhante (p>0,05) ao PH- 10 dias (0,278 ± 0,064), PH + LED laser/10 dias (0,280 ± 0,078), PH/14 dias (0,281 ± 0,104), PH + LED laser/14 dias (0,277 ± 0,093). Resistência de união inferior foram verificadas para PH/1 dia (0,082 ± 0,012), PH/3 dias (0,079 ± 0,013), PH + LED laser/1 dia (0,073 ± 0,018) e PH + LED laser/3 dias (0,080 ± 0,015), que foram estatisticamente semelhantes entre si (p>0,05). HP/7 dias (0,184 ± 0,154) e PH + LED laser/7 dias (0,169 ± 0,102) apresentaram valores intermediários (p<0,05). O procedimento restaurador da dentina intracoronária clareada com peróxido de hidrogênio 38 por cento, com ou sem o uso de fonte de luz, deve ser realizado pelo menos após 10 dias do tratamento clareador.


Subject(s)
Humans , Dental Bonding , Dentin/ultrastructure , Hydrogen Peroxide/chemistry , Oxidants/chemistry , Tooth Bleaching Agents/chemistry , Acid Etching, Dental/methods , Bisphenol A-Glycidyl Methacrylate/chemistry , Composite Resins/chemistry , Dental Stress Analysis/instrumentation , Dentin-Bonding Agents/chemistry , Lasers, Semiconductor , Materials Testing , Phosphoric Acids/chemistry , Shear Strength , Stress, Mechanical , Time Factors , Tooth Bleaching/methods
16.
ROBRAC ; 17(43): 32-38, jun. 2008. tab, ilus
Article in Portuguese | LILACS-Express | LILACS | ID: lil-525099

ABSTRACT

O presente estudo avaliou a atividade antiinflamatória de antiinflamatórios não-esteroidais (AINEs)em tecido pulpar de ratos, por meio de microscopia óptica. Preparos cavitários foram realizados nos incisivossuperiores de 40 ratos para a indução de processo inflamatório pulpar. Os animais foram distribuídos aleatoriamenteem 5 grupos segundo a medicação administrada: G1 - celecoxib; G2 - rofecoxib; G3 - diclofenacode sódio; G4 - ibuprofeno e G5 - solução fisiológica (controle). A terapia com AINEs foi iniciada apo?s 24 horasda realização da exposição pulpar. Nos períodos de 1, 3, 5 e 7 dias após o início da terapia medicamentosa,2 animais de cada grupo foram sacrificados e tiveram seus dentes extraídos para a análise histológica dotecido pulpar. Os índices utilizados para avaliação qualitativa variaram de 1 (tecido quase regenerado) até6 (inflamação severa). Os dados foram analisados por meio de Análise de Variância e teste de Tukey. Verificou-se que todos os medicamentos testados foram capazes de reduzir a inflamação quando comparadosao grupo controle. O grupo tratado com celecoxib apresentou os melhores resultados na redução do quadroinflamatório (p<0,01), seguido pelo rofecoxib e ibuprofeno, que se comportaram de maneira estatisticamentesemelhantes entre si (p>0,01) e superiores ao diclofenaco de sódio (p<0,01).


This study evaluated the anti-inflammatory effect of non-steroids anti-inflammatory (AINEs) in rat´s pulps,behind optic microscopy. Cavities were done in maxillary incisors of 40 rats to induce pulp inflammatory.The animals were divided in 5 groups according to medication: G1 - celecoxib; G2 - rofecoxib; G3 - diclofenacode sódio; G4 - ibuprofeno and G5 - saline (control). The therapy was initialized 24 hours after the pulpexposition. In the periods of 1, 3, 5 and 7 days after the therapy, 2 animals of each group were sacrificedand had their teeth extracted to histological analysis of pulp tissue. The scores were 1 (healed tissue) to 6(severe inflammation). The data were evaluated by Variance analysis and Tukey´s test. It was verified thatall medicaments were capable to reduce inflammation compared to control group. The celecoxib group presentedthe best results in reduction of inflammation (p<0,01), followed by rofecoxib and ibuprofeno, whichwere statistically equal (p>0,01) and better than diclofenaco de sódio (p<0,01).

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