ABSTRACT
Objetivo: Este estudo avaliou o efeito da solução de gluconato de clorexidina 0,2% (CHX) usado como primer terapêutico sobre a resistência de união longitudinal de adesivo convencional a dentina. Material e Métodos: dentes bovinos foram desgastados para obter uma área de dentina, e foram divididos em 2 grupos: Grupo C (Controle) - ácido fosfórico à 37%) + 0,2% CHX por 30s + Single Bond. Blocos de resina composta form fabricados e armazenados por 24 h e 6 meses, seccionados e submetidos ao teste de resistência a microtração. Os resultados foram analisados por ANOVA dois-fatores seguido pelo teste de Tukey. Resultados: Valores de média (±Desvio-padrão) (MPa): Grupo CHX/24h - 41,8(±2,62)A; Grupo C/24h - 40,8(±3,35)AB; Grupo CHX/6 meses 36,4(±3,52)B; Grupo CHX/6 meses - 26,1(±1,54) C. Resultados: Valores de média (±Desvio-padrão) (MPa): CHX (24 h) 41,76 (±2,62)a; C (24h) 40,81 (±3,35)ab; GT (24h): 37,38(2,98)abc; CHX (6 meses) 36,04 (±3,52) bcd; EGCG (24h) 35,91 (±4,82)cd; EGCG (6 meses) 35,75 (±4,44)cd; GT (6 meses) 31,95 (±3,40)de; C (6 meses): 30,05 (±1,54)e. Conclusão: CHX aumentou a resistência de união imediata da interface dentina-resina e significantemente reduziu a perda de resistência de união após 6 meses de armazenagem em água quando comparado ao grupo controle.(AU)
Objective: This study evaluated the effect of 0.2% chlorhexidine gluconate solution used as an therapeutic primer on the long-term bond strength of etch-and-rinse adhesive to dentin. Material and Methods: Bovine incisors were worn to expose an area of dentin and were divided into 2 groups: Group C (Control) - acid etching with 37% phosphoric acid + Single Bond; Group CHX (0.2% CHX) - acid etching with 37% phosphoric acid + 0.2% CHX for 30 s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukey tests. Results: Mean (±SD) values (in MPa) were as follow: Group CHX/24h - 41.8(±2.62)A; Group C/24h - 40.8(±3.35)AB; Group CHX/6 months 36.4(±3.52)B; Group CHX/6 months - 26.1(±1.54)C. Conclusion: CHX improve the imediatte bond strength of resin-dentin and significantly lowered the loss of bond strength after 6 months water storage as seen in the control bonds.(AU)
Subject(s)
Animals , Cattle , Chlorhexidine , Composite Resins , Dentin , Dentin-Bonding AgentsABSTRACT
ABSTRACT Objective: The aim of this study was to evaluate the effects of toothbrushing using a fluoride toothpaste and Aloe vera tooth gel on artificial white spot lesions through the Knoop microhardness (KHN) analysis. Methods: Sound bovine enamel samples (2 mm/diameter and 2 mm/depth) were prepared and immersed in artificial white spot lesion for 24 h. The preparation of artificial white spot lesions was performed by pH-cycling process. The samples were randomly divided into two groups (n=20), according the dentifrice used: containing fluoride (Colgate Total 12) or Aloe vera (Forever Bright Aloe Vera Toothgel). The top surface of samples was submitted to 10,000, 25,000, 50,000 and 100,000 brushing cycles (200 g load) in an automatic brushing machine with abrasive slurry. The KHN analysis were evaluated at baseline, after immersion in artificial white spot lesion and after 10,000, 25,000, 50,000 and 100,000 cycles of brushing. Data were analyzed by two-way repeated measures ANOVA and Tukey tests (p=0.05). Results: The KHN values significantly increased after brushing cycles compared to demineralized means. No significant differences showed for dentifrice factor (p=0.263). However, there were statistically significant differences between groups in cycles of brushing times (p=0.0001). Conclusion: The toothpastes (containing fluoride or Aloe vera) were effective in increasing the superficial microhardness of artificial white spot lesions.
RESUMO Objetivo: Avaliar o efeito da escovação simulada usando creme dental com flúor e Aloe vera em lesão de mancha branca artificial in vitro, através da análise da microdureza Knoop (KHN). Métodos: Amostras de esmalte bovino (2 mm/diâmetro e 2 mm/altura) foram preparados e imersos em solução artificial de cárie por 24 h. O preparo para indução de lesão de mancha branca foi realizado por processo de ciclagem de pH. As amostras foram aleatoriamente divididas em dois grupos (n=20), de acordo com o dentifrício utilizado: creme dental contendo flúor (Colgate Total 12) ou creme dental à base de Aloe vera (Forever Bright Aloe Vera Toothgel). A superfície das amostras foi submetida à 10.000, 25.000, 50.000 e 100.000 ciclos de escovação simulada (200 g/peso) em uma máquina de escovação. A análise de microdureza (KHN) foi realizada inicialmente, após o período de imersão em solução artificial de mancha branca e após 10.000, 25.000, 50.000 e 100.000 ciclos de escovação. Os dados foram submetidos aos testes RM-ANOVA dois fatores e Tukey (p=0.05). Resultados: Os valores de KHN aumentaram significantemente após os ciclos de escovação, quando comparado aos valores após a imersão em solução desmineralizante. Não houve diferenças estatisticamente significantes entre os cremes dentais (p=0.263). Entretanto, em relação aos ciclos de escovação, houve diferenças significantes (p=0001). Conclusão: Os cremes dentais (contendo flúor ou Aloe vera) foram efetivos no aumento da microdureza superficial em lesão artificial de mancha branca.
ABSTRACT
Objetivo: este estudo avaliou o efeito da solução de gluconato de clorexidina 0,2% (CHX), do chá verde e do componente ativo epigallocatequina 3-gallato (gel de EGCG) usados como primers terapêuticos sobre a resistência de união longitudinal de adesivo convencional a dentina. Material e Métodos: oitenta dentes bovinos foram desgastados para obter uma área de dentina plana, que foi condicionada (ácido fosfórico à 37%) seguida de lavagem. Os dentes foram divididos em 4 grupos (n- 20): Grupo C (Controle) - Single Bond; Grupo CHX 0,2% CHX por 30s + Single Bond; Grupo EGCG - gel de EGCG 10µM por 30s + Single Bond; Group GT chá verde aquoso por 30s + Single Bond. Blocos de resina composta form fabricados e armazenados por 24 h e 6 meses, seccionados e submetidos ao teste de resistência a microtração. Os resultados foram analisados por ANOVA dois-fatores seguido pelo teste de Tukey. Resultados: Valores de média (±Desvio-padrão) (MPa): CHX (24 h) 41,76 (±2,62)a; C (24 h) 40,81 (±3,35)ab; GT (24h): 37,38(2,98)abc; CHX (6 meses) 36,04 (±3,52) bcd; EGCG (24h) 35,91 (±4,82)cd; EGCG (6 meses) 35,75 (±4,44)cd; GT (6 meses) 31,95 (±3,40)de; C (6 meses): 30,05 (±1,54)e. Conclusão: O gel de EGCG produziu uma interface adesiva dentina-resina que não alterou os valores de resistência de união após 6 meses de armazenagem em água, mas reduziu a resistência de união para o tempo de 24 h quando comparado com os grupos Controle e CHX.
Objective: This study evaluated the effect of 0.2% chlorhexidine gluconate solution (CHX), green tea and active epigallocatechin-gallate (EGCG) used as therapeutic primers on the longterm bond strength of etch-and-rinse adhesive to dentin. Material and Methods: Eighty bovine incisors were worn to expose an area of dentin, that were acid-etched (37% phosphoric acid) and rinsed. The teeth were divided into 4 groups (n = 20): Group C (Control) - Single Bond; Group CHX - 0.2% CHX for 30s + Single Bond; Group EGCG - active EGCG gel at 10 µM for 30 s + Single Bond; Group GT - aqueous green tea for 30s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukeys test (5%). Results: Mean (±SD) values (in MPa) were as follow: CHX (24 h) 41.76 (±2.62); C (24 h) - 40.81 (±3.35); GT (24 h): 37.38(2.98); CHX (6 months) - 36.04 (±3.52); EGCG (24h) - 35.91 (±4.82); EGCG (6 months) - 35.75 (±4.44); GT (6 months) - 31.95 (±3.40); C (6 months): 30.05 (±1.54). Conclusion: EGCG produced resin-dentin bonds that did not change after 6 months water storage but it decreased the immediate bond strength when compared to control and chlorhexidine groups
Subject(s)
Animals , Cattle , Camellia sinensis , DentinABSTRACT
Objective: To compare he influence of two activation modes on two similar dual-polymerized resin cements. Methods: Bars (2 × 2 × 12 mm) of RelyX ARC (3M ESPE, MN, USA) (ARC) and Enforce (Dentsply, Rio de Janeiro, Brazil) (ENF) were prepared, and three types of polymerization method were tested: (1) L: LED photoactivation/40 s; (2) H: halogen Light activations/40 s, and (3) C: chemical activation only (Complete absent of light). The groups were ARC-L; ARC-H, ARC-C, Enf-L, Enf-H, and Enf-C (n = 8). After 24 h, the specimens were tested using the 3-point bending method on a universal testing machine. Results: The ARC cement showed superior flexural strength results. The mode of activation revealed similar results on both cements tested, but lightactivated groups (with LED or Halogen light) showed higher flexural strength values than did the chemical-activation-only group. Conclusion: (1) RelyX ARC cement showed superior flexural strength when compared with Enforce; and (2) light activation resulted in better flexural strength values when compared to chemical activation on dual-polymerized resin cements.
Objetivo: Comparar a influência do modo de ativação de dois cimentos semelhantes, porém de fabricantes distintos. Métodos: Barras (2 x 2 x 12 mm) dos cimentos RelyX ARC (3M ESPE, MN, USA) e Enforce (Dentsply, Rio de Janeiro, Brasil) (ENF) foram confeccionadas com auxílio de uma matriz de teflon bipartida, e três modos de fotopolimerização foram testados: (1) L: fotoativação por LED / 40 segundos; (2) H - fotoativação por luz halógena / 40 segundos; e (3) Q - apenas ativação química (ausência total de luz). Os grupos formados foram: ARC-L; ARC-H; ARC-Q; Enf-L; Enf-H e Enf-Q, com 8 amostras cada. Após 24 horas, o teste de miniflexão de três pontos foi aplicado em máquina universal de testes. Resultados: O cimento ARC apresentou resultados de resistência superiores ao cimento Enf. O modo de ativação agiu de forma semelhante nos dois cimentos testados, sendo que a ativação por luz, seja L ou H, aumentou a resistência para ambos, comparada a ativação Q. Conclusão: (1) O cimento RelyX ARC (3M ESPE, MN, USA) apresentou maior resistência à flexão de três pontos quando comparado ao cimento Enforce(Dentsply, Rio de Janeiro, Brasil); e (2) a ativação por luz aumentou a resistência para cimentos resinosos duais.
Subject(s)
Self-Curing of Dental Resins , Resin Cements , Materials ScienceABSTRACT
Objective: The aim of this study was to evaluate the erosive effect of three beverages which are considered to be acidic in vitro study.Methods: We used 45 third molars. The teeth were cut to obtain 90 4x4 mm enamel blocks, obtained from the buccal and lingual surfaces of each tooth. The groups were divided by type of beverage (Coca-Cola®, Coca-Cola do Brasil, Rio de Janeiro, Brazil; Coca-Cola Zero®, Coca-Cola do Brasil, Rio de Janeiro, Brazil and Gatorade uva®, Ambev, Jaguariúna, Brazil) and number of cycles (7, 15 and 30 cycles). For each cycle, the specimens were immersed in the drink for 2.5 minutes by alternating with immersion in saliva for 1 hour. Each cycle simulates one day of intake. Statistical analysis, ANOVA and Tukey 5% for profilometry showed the statistical difference between the kind of beverages and between periods.Results: Coca-Cola® (Coca-Cola do Brasil, Rio de Janeiro, Brazil) (3.99±1.25) differed from other kinds of beverage. All the periods differed and the period of 30 days saw the greatest structural loss. For microhardness, the statistical analysis showed greater loss of surface hardness for the group Coca-Cola® (Coca-Cola do Brasil, Rio de Janeiro, Brazil) within 30 days (126.02 ± 30.98) SHL. Conclusion: IIt was concluded that the soft drink Coca Cola® (Coca-Cola do Brasil, Rio de Janeiro, Brazil) had the greatest erosive effects and the higher the number of cycles the greater the influence on the process of dental erosion.
Objetivo: Avaliar o efeito erosivo de três bebidas ácidas sobre o esmalte dentário num estudo in vitro. Métodos: Foram utilizados 45 terceiros molares humanos. Noventa blocos de esmalte de dente humano (4X4 mm) foram obtidos a partir das faces vestibular e lingual de terceiros molares. Os blocos de esmalte foram divididos de acordo com o tipo de bebida testada (Coca-Cola®, Coca-Cola do Brasil, Rio de Janeiro, Brasil; Coca-Cola Zero®, Coca-Cola do Brasil, Rio de Janeiro, Brasil e Gatorade uva®, Ambev, Jaguariúna, Brasil) e quantidade de ciclos (7, 15 e 30 ciclos). Cada ciclo simulava um dia de ingestão, o qual compreendia a imersão dos corpos de prova (n=10/tipo de bebida e quantidade de ciclos) nas bebidas (2,5 minutos), alternados por imersão em saliva (1 hora). Para quantificação do efeito erosivo, foi avaliada a perfilometria (?m±DP) e a perda de dureza superficial. Os dados foram analisados por ANOVA 2 fatores e Tukey 5%. Resultados: A perfilometria demonstrou diferença estatística entre as bebidas e entre os períodos, sendo que a Coca-Cola® (Coca-Cola do Brasil, Rio de Janeiro, Brasil) (3.99±1,25) diferiu das outras bebidas. Todos os períodos diferiram entre si sendo que para o período de 30 dias ocorreu a maior perda de estrutura. Para a microdureza a análise estatística demonstrou maior perda de dureza superficial para o grupo Coca-Cola® (Coca-Cola do Brasil, Rio de Janeiro, Brasil) no período de 30 dias (126,02 ± 30,98) perda de dureza superficial. Conclusão: Concluiu-se que a Coca-Cola® (Coca-Cola do Brasil, Rio de Janeiro, Brasil) apresentou os maiores efeitos erosivos e quanto maior número de ciclos, maior a influência no processo dentário erosivo.
Subject(s)
Beverages , Dental Enamel , Hardness TestsABSTRACT
Objetivo: O objetivo deste estudo foi avaliar a resistência de união dentinária tratada com clorexidina, ácido hialurônico, vitamina C e chá verde. Material e Métodos: As raízes de 50 dentes bovinos foram removidas e a superfície de dentina vestibular exposta. Após o condicionamento ácido, os espécimes foram divididos em 5 grupos (n = 10), de acordo com as estratégias adesivas na dentina: CO - dentina não tratada; CHX tratamento com clorexidina 2% por 30 s; HA - tratamento com ácido hialurônico 1% por 30 s; VC - tratamento com vitamina C 10% por 30 s; GT tratamento com extrato de chá verde 1% por 30 s. Sistema adesivo Adper Single Bond II foi aplicado segundo recomendações do fabricante. Os espécimes foram restaurados com uma camada de 4 mm de espessura de resina composta, que foi polimerizada por 40 s. As amostras foram armazenadas em água destilada a 37 ° C durante 24 h, e seccionada em palitos de 1 x 1 mm2 contendo a interface adesiva. Teste de microtração foi realizado com uma máquina de ensaios universal a uma velocidade de 0,5 mm/min. Resultados: Os resultados foram analisados com teste de variância ANOVA um-fator e testes de múltipla comparação de Tukey (p < 0,05). Grupo GT apresentou os maiores valores de resistência de união (29,4 ± 3,1) a, mas sem diferença significativa em relação aos demais grupos experimentais HA (26,7 ± 3,1) ab, CHX (25,4 ± 2,6) ab e VC (22,4 ± 6,0) b. Resistência de união dos grupos experimentais não foi significativamente diferente do grupo CO. Conclusão: a resistência de união imediata foi mantida mesmo após os diferentes tratamentos dentinários.
Objective: The aim of this study was to evaluate the bond strength of dentin treated with chlorhexidine, hyaluronic acid, vitamin C and green tea. Material and Methods: The roots of 50 bovine teeth were removed and buccal coronal dentin was exposed. After acidetching, the specimens were divided into 5 groups (n= 10), according to the dentin treatment strategy: CO -untreated dentin; CHX - treated with 2 wt% chlorhexidine for 30 s; HA - treated with 1 wt% hyaluronic acid for 30s; VC - treated with 10 wt% vitamin C for 30 s; GT - treated a 1% green tea extract for 30 s. Adper Single Bond was then applied to the treated according to the manufacturers recommendations. The specimens were restored with a 4 mm thick layer of the resin composite, which was polymerized for 40 s. The specimens were stored in distilled water at 37°C for 24 h and sectioned into 1 x 1 mm2 sticks containing the adhesive interface. Microtensile bond strength testing was performed with a universal testing machine at a cross-head speed of 1.0 mm/min. Results: The results were analyzed with onefactor ANOVA and Tukeys multiple comparison tests. GT group presented the highest values bond strength (29.4 ± 3.1) a, but no significant difference compared to the other experimental groups HA (26.7 ± 3.1) ab, CHX (25.4 ±2.6) ab and VC (22.4 ± 6.0) b. Bond strengths of experimental groups were not significantly different from the CO. Conclusion: Immediate bond strength was preserved after acid-etched dentin was treated.
Subject(s)
Animals , Cattle , Ascorbic Acid , Camellia sinensis , Chlorhexidine , Hyaluronic AcidABSTRACT
The aim of this study was to investigate the effects of some acidic drinks on dentin erosion, using methods of surface profile (SP) analysis and energy-dispersive X-ray fluorescence spectrometry (EDXRF). One hundred standardized dentin slabs obtained from bovine incisor roots were used. Dentin slabs measuring 5x5 mm were ground flat, polished and half of each specimen surface was protected with nail polish. For 60 min, the dentin surfaces were immersed in 50 mL of 5 different drinks (Gatorade®, Del Valle Mais orange juice®, Coca-Cola®, Red Bull® and white wine), 20 blocks in each drink. The pH of each beverage was measured. After the erosive challenge, the nail polish was removed and SP was analyzed. The mineral concentration of dentin surfaces was determined by means of EDXRF. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). SP analysis showed that Red-Bull had the highest erosive potential (p<0.05). EDXRF results exhibited a decrease in phosphate in the groups immersed in Red-Bull, orange juice and white wine (p<0.05), and no significant difference in calcium content between the reference surface and eroded surface. In conclusion, this study demonstrated that all studied beverages promoted erosion on root dentin and Red Bull had the highest erosive potential. There was no correlation between pH of beverages and their erosive potential and only the P content changed after erosive challenge.
O objetivo deste estudo foi investigar os efeitos de algumas bebidas ácidas sobre a erosão da dentina, utilizando métodos de análise de perfil de superfície (SP) e espectrometria de energia dispersiva de fluorescência de raios X (EDXRF). Cem blocos de dentina padronizados obtidos de raízes de incisivos bovinos foram utilizados. Os blocos de dentina medindo 5x5 mm foram planificados, polidos e metade de cada superfície das amostras foram impermeabilizados com esmalte para unhas. Por 60 min, as superfícies de dentina foram imersas em 50 mL de 5 bebidas diferentes (Gatorade, suco de laranja, Coca-Cola, Red Bull e vinho branco), 20 blocos em cada bebida. O pH de cada bebida foi medido. Após o desafio erosivo, o esmalte de unha foi removido e SP foram analisados. A concentração de minerais das superfícies de dentina foi determinada por meio de EDXRF. Os dados foram analisados estatisticamente por ANOVA e teste de Tukey. (p<0,05). A análise SP mostrou que o Red-Bull apresentou o maior potencial erosivo. Os resultados do EDXRF apresentaram uma diminuição do fosfato dos grupos imersos no Red-Bull, suco de laranja e vinho branco, e não houve diferença significativa no teor de cálcio entre a superfície de referência e a superfície que sofreu erosão. O Red Bull apresentou o maior potencial erosivo sobre a dentina radicular. Não houve correlação entre o pH das bebidas e o seu potencial erosivo.
Subject(s)
Animals , Cattle , Beverages/adverse effects , Dentin/pathology , Tooth Erosion/etiology , Acids , Citrus sinensis , Calcium/analysis , Carbonated Beverages/adverse effects , Energy Drinks/adverse effects , Hardness , Hydrogen-Ion Concentration , Phosphates/analysis , Spectrometry, X-Ray Emission , Time Factors , Wine/adverse effectsABSTRACT
Este estudo avaliou a microdureza da resina composta à base de silorano (RCS) fotoativada com luz halógena (LH) e LED, seguido da exposição aos colutórios bucais Periogard, Listerine e Colgate Plax Sem Álcool. Foram confeccionados 40 espécimes da RCS Filtek P90 e divididos em 2 grupos (n = 20): Grupo LED - fotoativação com LED por 40 s (1200 mW/cm2); Grupo LH - fotoativação com LH por 40 s (600 mW/cm2). Os espécimes foram distribuídos em 4 subgrupos (n-5) de acordo com o bochecho: Subgrupo C - imersos em saliva artificial por 7 dias; Subgrupo LI - agitados no colutório Listerine 1 vez ao dia por 1 minuto durante 7 dias, em seguida, armazenados em saliva artificial; Subgrupo CP - agitados no colutório Colgate Plax Sem Álcool, seguindo o mesmo protocolo acima; Subgrupo PE - agitados no colutório Periogard, seguindo o mesmo protocolo acima. Os espécimes foram submetidos ao ensaio de microdureza no Microdurômetro digital Vickers com três endentações e carga de 50 g/ 15 s e os dados, submetidos aos testes ANOVA dois fatores (Fonte de luz e Colutório bucal) e Tukey (5%). Houve diferença significante para os fatores Fonte de luz e Colutório bucal (p = 0,00). Os valores da microdureza para o fator Fonte de luz: Grupo LED - 72,61 a; Grupo LH - 67,21 b; para o fator Colutório bucal: Subgrupo C - 79,29 a; Subgrupo PL - 75,5 a; Subgrupo PE - 66,12 b; Subgrupo LI - 58,75c. Para o fator Fonte de luz, LED apresentou dureza superior a LH. Para o fator Colutório bucal, o armazenamento em saliva artificial apresentou dureza superior em relação ao uso dos colutórios Periogard e Listerine.
This study evaluated the microhardness of silorane-based composite resin cured with halogen light and LED, followed by the use of mouthwashes: Periogard, Listerine, and Colgate Plax Without Alcohol. Forty specimens were fabricated with silorane-based composite resin Filtek P90 and divided into two groups (n = 20): Group LED - LED light curing for 40 s (1200 mW/cm2), Group HL - Halogen light curing for 40 s (600 mW/cm2). The specimens were divided into four subgroups (n-5) in accordance with the use of the mouthwash: Subgroup C - immersed in artificial saliva for 7 days; Subgroup LI - Listerine mouthwash once daily for 1 minute during 7 days, then stored in artificial saliva; Subgroup CP - Colgate Plax Without Alcohol mouthwash, following the same protocol above; Subgroup PE - Periogard mouthwash, following the same protocol above. The specimens were subjected to microhardness test on digital Microhardness Vickers with three indentations and load of 50 g/ 15 s. The data were submitted to ANOVA two factors (Light and Mouthwash) and Tukey (5%). There were significant differences for the factors Light and Mouthwash (p = 0.00). The values of microhardness for Light Factor: LED Group - to 72.61 a and Group HL - 67.21 b; for Mouthwash Factor: Subgroup C - 79.29 a; subgroup PL - to 75.5 a; subgroup EP - 66.12 b; Subgroup LI - 58.75 c. For Light Factor, LED showed hardness higher than halogen light. For Mouthwash Factor, storage in artificial saliva showed higher hardness compared to the use of Listerine and Periogard mouthwashes.
ABSTRACT
OBJECTIVE: This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. MATERIAL AND METHODS: Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10), according to the root reconstruction protocol: Group I (control): non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05). RESULTS: Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. CONCLUSION: The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol.
Subject(s)
Humans , Composite Resins/therapeutic use , Glass , Post and Core Technique , Tooth Fractures/physiopathology , Tooth Root/injuries , Compressive Strength , Dental Restoration Failure , Dental Stress Analysis , Materials Testing , Root Canal Preparation/methods , Stress, Mechanical , Tooth Root/surgery , Tooth, Nonvital/therapyABSTRACT
OBJECTIVE: This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. MATERIAL AND METHODS: Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10), according to the root reconstruction protocol: Group I (control): non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05). RESULTS: Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. CONCLUSION: The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol.
Subject(s)
Composite Resins/therapeutic use , Glass , Post and Core Technique , Tooth Fractures/physiopathology , Tooth Root/injuries , Compressive Strength , Dental Restoration Failure , Dental Stress Analysis , Humans , Materials Testing , Root Canal Preparation/methods , Stress, Mechanical , Tooth Root/surgery , Tooth, Nonvital/therapyABSTRACT
Purpose: In addition to the chemical damage due to bleaching gels penetration into the pulp during pulp vitality dental bleaching, another possible aggressive factor could be the heat generated by the exothermal oxidation reaction of the bleaching gel, which may also be aggravated by the use of light activation. This study assessed the temperature variation in the pulp chamber in human teeth, using three different bleaching gels with or without LED light activation. Methods: Thirty human pre-molars were cut longitudinally to obtain buccal and lingual halves. The 60 specimens were divided into 3 groups, and the bleaching gel used varied as follows: 35% hydrogen peroxide (WHP); 37% carbamide peroxide (W) and 38% hydrogen peroxide (OX). Half of the specimens were submitted to bleaching with light activation and, the other half, without light activation. The light source used was the light emitting diode appliance (LED, 3-Light, Clean Line), and the intrapulpal temperatures were measured by using a digital thermometer. Data were analyzed by ANOVA and Tukey´s tests (alpha=5%). Results: The intrapulpal temperatures (in oC) were as follows: without light activation (WHP= 0.68b; W= 0.40b; OX= 0.48b); with light activation (WHP= 2.35a; W= 1.60a; OX= 1.80a ). Conclusion: LED light activation of bleaching gels increased the temperature in the pulp chamber, but did not achieve the critical temperature value of 5.5 oC.
Objetivo: Além da agressão química devido à penetração dos géis clareadores na polpa durante o clareamento de dentes com vitalidade pulpar, outro possível fator agressor pode ser o calor gerado pela reação de oxidação exotérmica do gel clareador, que pode também ser agravada pela fotoativação. Este estudo avaliou a variação da temperatura na câmara pulpar de dentes humanos, utilizando-se três diferentes géis clareadores, com ou sem fotoativação.Metodologia: Trinta pré-molares humanos foram cortados longitudinalmente para obtenção de duas metades: vestibular e lingual. Os 60 espécimes foram divididos em 3 grupos e os agentes clareadores utilizados variaram como segue: peróxido de hidrogênio 35% (WHP), peróxido de carbamida 37% (W) e peróxido de hidrogênio 38% (OX). Metade dos espécimes foi submetida ao clareamento com fotoativação e, a outra metade, sem fotoativação. A fonte de luz utilizada foi o aparelho à base de diodo emissor de luz (LED, 3-Light, Clean Line) e as temperaturas foram medidas por um termômetro digital. Os dados foram analisados por análise de variância e teste de Tukey (alfa=5%).Resultados: Os resultados de temperatura foram: sem fotoativação (WHP= 0.68b; W= 0.40b; OX= 0.48b); com fotoativação (WHP= 2.35a; W= 1.60a; OX= 1.80a).Conclusão: A fotoativação dos géis clareadores com LED contribuiu para um maior aumento de temperatura na câmara pulpar, mas não se atingiu a temperatura crítica de 5,5oC.
Subject(s)
Humans , Dental Pulp Cavity , Light/adverse effects , Peroxides/administration & dosage , Tooth Bleaching , Hot Temperature/adverse effectsABSTRACT
Introdução: as principais características dos CIVs são: liberação de flúor, biocompatibilidade, adesividade aos tecidos dentais duros e expansão térmica linear próxima à dentina. Objetivo: avaliar a capacidade dos cimentos de ionômero de vidro de promover à dentina maior resistência frente aos ácidos e microrganismos presentes na cavidade oral, discutindo a suposta bioatividade desse material relacionada ao substrato dentinário em diversas situações. Revisão de literatura: são inúmeras as opções e possibilidades de indicação dos CIVs, porém, a situação clínica deve ser avaliada com critério para escolher o material mais viável e aquele que ofereça o maior número de vantagens. Conclusões: os CIVs apresentam adesividade a estrutura dental, proporcionam vedamento marginal, reduzem a micro infiltração e/ou a passagem de nutrientes para os microorganismos que porventura possam estar presentes na cavidade. Devido à liberação de fluoretos, os CIVs apresentam potencial remineralizador ou paralisador mesmo em dentina cariada.
Introduction: the main characteristics of GICs are: fluoride release, biocompatibility, adhesion to dental hard tissues and linear thermal expansion similar the dentin. Aim: this literature review, based on the work currently available, evaluated the ability of glass ionomer cements to promote greater dentin resistance against acids and microorganisms presents in the oral cavity, discussing the supposed bioactivity of this material related to dentinary substrate in various situations. Literature review: there are countless options and possibilities for indication of GICs, however, the clinical situation must be evaluated on the criteria for selecting the material most viable and one that offers the greatest number of advantages. Conclusion: it was concluded that the GICs exhibit adhesion to tooth structure, providing marginal sealing, reduce microleakage and / or the passage of nutrients to the microorganisms who may be present in the cavity. Due to the release of fluoride, GICs have potential remineralizing paralyzing or even in carious dentin.
Subject(s)
Humans , Glass Ionomer Cements/chemistry , Dental Marginal Adaptation , Dental Restoration, Permanent , Fluorides/metabolism , Tooth Remineralization , Materials TestingABSTRACT
The aim of this in vitro study was to compare the photoactivation effects of QTH (Quartz-Tungsten-Halogen) and LED (Light-Emitting Diode) on the SBS (Shear Bond Strength) of orthodontic brackets at different debond times. Seventy-two bovine lower incisors were randomly divided into two groups according to the photoactivation system used (QTH or LED). The enamel surfaces were conditioned with Transbond self-etching primer, and APC (Adhesive Pre-Coated) brackets were used in all specimens. Group I was cured with QTH for 20 s and Group II with LED for 10 s. Both groups were subdivided according to the different experimental times after bonding (immediately, 24 h and 7 days). The specimens were tested for SBS and the enamel surfaces were analyzed according to the Adhesive Remnant Index (ARI). The statistical analysis included the Tukey's test to evaluate the main effects of photoactivation and debond time on SBS. The Chi-square test was used to compare the ARI values found for each group, and no statistically significant difference was observed. The debond time of 7 days for QTH photoactivation showed statistically greater values of SBS when compared to the immediate and 24 h periods. There was no statistically significant difference between the QTH and LED groups immediately and after the 24 h period. In conclusion, bonding orthodontic brackets with LED photoactivation for 10 s is suggested because it requires a reduced clinical chair time.
Subject(s)
Curing Lights, Dental , Light-Curing of Dental Adhesives/methods , Orthodontic Brackets , Shear Strength/radiation effects , Acid Etching, Dental , Animals , Cattle , Dental Debonding , Materials Testing , Resin Cements/radiation effects , Surface Properties/radiation effects , Time FactorsABSTRACT
Purpose: The aim of this study was to assess the influence of topical acidulated phosphate fluoride on the surface roughness of both human enamel and different restorative materials. Methods: Resin-modified glass ionomer (Vitremer = V), microhybrid composite resin with fluoride (Tetric Ceram = T), and nanofiller composite resin without fluoride (Z350 = Z) were evaluated. Acidulated phosphate fluoride (APF, 1.23%) was applied to half of the specimens (groups VF, TF, ZF and EF). Ten intact human third molars were used to obtain enamel specimens (E). Six experimental groups (n=10) and two control groups (n=10) were formed. The mean surface roughness (Ra) of both the restorative materials and enamel, with and without fluoride, was evaluated with a profilometer. Data were analyzed with an ANOVA, Tukey's test, Student's t-test, and Dunn-Bonferroni test at the 5% significance level. Results: The mean values of surface roughness, in micrometers, were as follows: Z=0.60; TF=1.00; ZF=1.05; VF=1.18; T=2.10; V=2.70; E=16.99; and EF=21.19. Both E and EF presented significantly higher surface roughness than the other experimental groups. Conclusion: It was concluded that APF increased the surface roughness of enamel and decreased the surface roughness of both resin-modified glass-ionomer cement and microhybrid composite resin with fluoride. The surface roughness of the nanofiller composite resin was not modified by APF.
Objetivo: Este estudo avaliou a influência da aplicação tópica de flúor fosfato acidulado sobre a rugosidade do esmalte e de diferentes materiais restauradores. Metodologia: Amostras de cimento de ionômero de vidro modificado por resina (Vitremer - V), resina composta microhíbrida com flúor (Tetric Ceram - T) e resina nanopartículada sem flúor em sua composição (Z350 - Z) foram confeccionadas. Metade das amostras recebeu aplicação tópica de flúor fosfato acidulado a 1,23% (FFA) (grupos VF, TF, ZF e EF) e a outra metade não, totalizando 6 grupos experimentais (n=10). Dez terceiros molares humanos hígidos foram utilizados para confecção de amostras de esmalte (E), constituindo os grupos controles (n=10). A rugosidade média superficial (Ra) dos materiais restauradores e do esmalte, com e sem flúor, foi analisada pelo rugosímetro. Os dados foram submetidos à análise de variância, testes de Tukey, t-Student e de Dunn-Bonferroni (5 % de significância). Resultados: Os valores médios de rugosidade, em micrômetros, foram: Z=0,60; TF=1,00; ZF=1,05; VF=1,18; T=2,10; V=2,70; E=16,99 e EF=21,19. E e EF apresentaram Ra significativamente superior aos grupos experimentais. Conclusão: Concluiu-se que o FFA aumentou a rugosidade do esmalte, diminuiu a do cimento de ionômero de vidro e da resina microhíbrida com flúor e não alterou a rugosidade da resina nanoparticulada sem flúor.
Subject(s)
Humans , Composite Resins , Dental Enamel , Fluorine/adverse effects , Glass Ionomer Cements , Case-Control StudiesABSTRACT
The aim of this in vitro study was to compare the photoactivation effects of QTH (Quartz-Tungsten-Halogen) and LED (Light-Emitting Diode) on the SBS (Shear Bond Strength) of orthodontic brackets at different debond times. Seventy-two bovine lower incisors were randomly divided into two groups according to the photoactivation system used (QTH or LED). The enamel surfaces were conditioned with Transbond self-etching primer, and APC (Adhesive Pre-Coated) brackets were used in all specimens. Group I was cured with QTH for 20 s and Group II with LED for 10 s. Both groups were subdivided according to the different experimental times after bonding (immediately, 24 h and 7 days). The specimens were tested for SBS and the enamel surfaces were analyzed according to the Adhesive Remnant Index (ARI). The statistical analysis included the Tukey's test to evaluate the main effects of photoactivation and debond time on SBS. The Chi-square test was used to compare the ARI values found for each group, and no statistically significant difference was observed. The debond time of 7 days for QTH photoactivation showed statistically greater values of SBS when compared to the immediate and 24 h periods. There was no statistically significant difference between the QTH and LED groups immediately and after the 24 h period. In conclusion, bonding orthodontic brackets with LED photoactivation for 10 s is suggested because it requires a reduced clinical chair time.
Subject(s)
Animals , Cattle , Curing Lights, Dental , Light-Curing of Dental Adhesives/methods , Orthodontic Brackets , Shear Strength/radiation effects , Acid Etching, Dental , Dental Debonding , Materials Testing , Resin Cements/radiation effects , Surface Properties/radiation effects , Time FactorsABSTRACT
Purpose: The aim of this in vitro study was to evaluate whether using different types of light activation during the in-office bleaching agent technique increases the effectiveness of the dental bleaching procedure by measuring the color change in teeth. Methods: From 60 extracted bovine incisor teeth, specimen sizes were standardized and dentin was conditioned by immersion in 38% phosphoric acid for 15 s. Following this procedure, the samples were placed in a water bath with ultrasound for 20 min and then immersed in a 25% coffee solution for a two-week period. The dentin was polished with a felt disc and aluminum oxide paste and finally sealed with colorless nail polish. Specimens were randomly divided into five groups, and their original color was measured using the EasyShade (VITA) spectrophotometer. All specimens received three applications of the bleaching agent Opalescence Xtra-Boost (Ultradent) during a period of 15 min each. Group 1 did not receive light activation, Group 2 was activated with a Halogen light (15 min), Group 3 was activated with a blue hybrid LEDs and a laser (15 min), Group 4 was activated with light from a green LED and a laser (15 min) and Group 5 was activated with a red laser (15 min). Tooth color was measured again after performing the various bleaching techniques on all specimens. The resulting data on color variations ΔE, Δa*, Δb* and ΔL*, and the color variations referenced on the Vita Classical scale were subjected to ANOVA, Tukey and Dunn tests (α=5%). Results: The bleaching performance of 38% hydrogen peroxide was affected by the light source used; color reduction was observed for the blue LED and halogen lights, and quantitative assessments of tooth color measured by spectrophotometer and matched to the Vita Classical color scale arrived at similar results in all experimental groups. Conclusions: The type of hybrid lights used interferes in the efficiency of the bleaching agent.
Objetivo: Avaliar se fontes de luz aumentam a eficácia do peróxido de hidrogênio na técnica de clareamento profissional. Metodologia: Foram empregados 60 dentes incisivos bovinos, com dimensões coronárias e radiculares padronizadas a partir do limite amelo-cementário, sendo descartada a porção lingual. Os corpos-de-prova (cp) foram limpos em ultra-som por 20 min e a dentina condicionada com H3PO4 a 38% por 15 s, sendo os (cp) imersos em solução de café solúvel a 25% por duas semanas. A dentina foi impermeabilizada com esmalte e os (cp) divididos em 5 grupos, sendo a cor inicial mensurada através do espectofotômetro-EasyShade (VITA). Todos os (cp) receberam três aplicações por 10 min do gel clareador Opalescence Xtra-Boost (Ultradent) conforme segue: Grupo 1 - controle, não recebeu fotoativação, Grupo 2 - ativado com luz halôgena, Grupo 3 - ativado com LED azul/LASER, Grupo 4 - ativado com LED verde/LASER e Grupo 5 - ativado com LED vermelho. Após o clareamento foi mensurada a variação de cor ΔE, Δa*, Δb*e ΔL* e as referentes à escala de cor Vita Clássico. Os dados foram submetidos à análise de variância, teste de Tukey e de Dunn (α=5%). Resultados: A diferença geral da cor foi reduzida quando se empregou LED Azul e Luz Halógena, sendo que o desempenho do peróxido de hidrogênio a 38 % foi intensificado dependendo da fonte de luz utilizada. A avaliação quantitativa de cor, obtida por espectrofotômetro e pela escala de cor Vita Clássico, foram coincidentes. Conclusão: O tipo de fonte de luz empregada interfere na eficácia do agente clareador.
Subject(s)
Animals , Cattle , Tooth Bleaching/methods , In Vitro Techniques , Lasers , Curing Lights, Dental , Hydrogen Peroxide , Case-Control StudiesABSTRACT
Objetivos: O objetivo desse estudo foi avaliar a microinfiltração em restaurações de classe V de resina composta utilizando sistemas adesivos convencionais e autocondicionante. Material e Métodos: Avaliou-se, in vitro a ocorrência e a intensidade da microinfiltração inicial (24 horas) e aos 6 meses. Foram utilizados 40 molares humanos extraídos por razões ortodônticas, com consentimento dos pacientes, nos quais se confeccionaram preparos cavitários de classe V padronizadas nas faces vestibular e lingual. As amostras foram divididas em 3 grupos com diferentes sistemas adesivos: SB - Adper Single Bond (3M ESPE); PB - Prime & Bond NT (Denstply) convencionais com utilização de condicionamento ácido; e OP - One Up Bond F Plus (Tokuyama) sistema adesivo autocondicionante, todos adesivos foram utilizados de acordo com as indicações dos fabricantes. Após os diferentes tempos de armazenagem, as amostras foram imersas por 24 horas em Rodamina B a 2%, lavadas, secas, seccionadas conforme um plano axial vestíbulo-lingual passando pelo centro das restaurações. A microinfiltração foi avaliada de acordo com o grau de infiltração do corante e classificado pelo critério de escores. Resultados: Os resultados mostraram os seguintes valores para médios de microinfiltração: 24 horas SB-2,5; Pb - 2,7; e OP - 3,0; 6 meses SB - 3,8; PB - 4,1; e OP - 3,6. Conclusão: Concluiu-se que os sistemas adesivos foram incapazes de impedir a microinfiltração e que houve aumento da mesma entre 24 horas e 6 meses em todos os sistemas adesivos estudados.
Objectives: The objective of this study was to evaluate the microleakage in class V restorations of composite resin using conventional adhesive systems and self-etching. Material and Methods: Evaluated in vitro the occurrence and the intensity of the initial microleakage (24 hours) and to the 6 months. 40 molars human extracted were used by reasons orthodontics, with the patients consent, which preparations class V cavitations were made standardized in the faces vestibular exam and lingual. The specimens were divided in 3 groups with different adhesive systems: SB - Adper Single Bond (3M ESPE); PB - Prime & Bond NT (Denstply) with conventional conditioning acid; and OP - One Up Bond F Plus (Tokuyama) used in agreement with the manufacturers indications. After the different times of storage, the specimens were immersed by 24 hours in Rodamina B to 2%, washed, droughts, sectioned according to a axial plan vestibular-lingual going by the center with penetration of the color and evaluating the infiltration degree for the criterion of Escores. Results: The results showed the following values for medium of micro leakage: 24 hours SB-2,5; Pb -2,7; and OP - 3,0; 6 months SB - 3,8; PB - 4,1; and OP - 3,6. Conclusion: It was ended that the adhesive systems were unable to impede the micro leakage and that there was increase of the same between 24 hours and 6 months in all the studied adhesive systems.
Subject(s)
Humans , Dentin-Bonding Agents/chemistry , Dental Bonding , Dental Leakage , Composite Resins/chemistry , Statistics, Nonparametric , Dental Cavity Preparation , Dental Restoration, PermanentABSTRACT
OBJECTIVES: The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35 percent hydrogen peroxide using different sources of activation. MATERIAL AND METHODS: Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12): (G1) Control - Bleaching gel without light activation, (G2) Bleaching gel + halogen light, (G3) Bleaching gel + LED, (G4) Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel. Data were analyzed statistically by the Dunnet's test, ANOVA and Tukey's test (a=0.05). RESULTS: The mean intrapulpal temperature values (ºC) in the groups were: G1: 0.617 ± 0.41; G2: 1.800 ± 0.68; G3: 0.975 ± 0.51; and G4: 4.325 ± 1.09. The mean maximum temperature variation (MTV) values were: 1.5ºC (G1), 2.9ºC (G2), 1.7ºC (G3) and 6.9ºC (G4). When comparing the experimental groups to the control group, G3 was not statistically different from G1 (p>0.05), but G2 and G4 presented significantly higher (p<0.05) intrapulpal temperatures and MTV. The three experimental groups differed significantly (p<0.05) from each other. CONCLUSIONS: The Nd:YAG laser was the activation method that presented the highest values of intrapulpal temperature variation when compared with LED and halogen light. The group activated by LED light presented the lowest values of temperature variation, which were similar to that of the control group.
Subject(s)
Humans , Body Temperature/drug effects , Dental Pulp/drug effects , Hydrogen Peroxide/therapeutic use , Light , Oxidants/therapeutic use , Tooth Bleaching/methods , Gels , Hydrogen Peroxide/administration & dosage , Hydrogen Peroxide/radiation effects , Lasers, Solid-State/therapeutic use , Lighting/instrumentation , Materials Testing , Oxidants/administration & dosage , Oxidants/radiation effects , Thermometers , Time FactorsABSTRACT
The aim of this study was to evaluate the sealing of indirect resin restorations cemented with three different luting agents. Thirty bovine teeth were used. Box type cavities preparations were made in the middle third of the buccal face. The cavities were restored with inlay restorations by the direct/indirect technique using resin composite Resilab (Wilcos, Petrópolis, RJ, Brazil). The teeth were randomly divided into three groups: Group 1: etched with 37% phosphoric acid for 30 seconds, adhesive system Prime Bond 2.1 and Enforce resin cement (Dentsply, Petrópolis, RJ, Brazil); Group 2:etched with 37% phosphoric acid for 30 seconds, adhesive system Single Bond and RelyX ARC resin cement (3M ESPE,St Paul, MN, USA); and Group 3: resin-modified glass ionomer cement RelyX Unicem Aplicap (Dentsply, Petrópolis,RJ, Brazil). The indirect restorations were cemented with the respective cements and thermal cycled for 800 cycles. The specimens were stored in 50% silver nitrate dye for 24 hours, after this procedure the teeth were sectioned in the bucco-lingual direction into 3 slices of 1 mm thick, fixed on a glass slide and then analyzed by a stereomicroscope were was coupled a digital camera to register the images. From these pictures, the marginal leakage areas were measuredby the software Image Tool 3.0. The data obtained were submitted to the ANOVA and Tukey tests. ANOVA showedthat there was no significant difference (p=0.73) among groups (mean values(±SD): Group 1=0.96(±0.71); Group 2:1.10(±0.63) and Group 3: 0.99(±0.35) . It was concluded that the 3 luting agents presented no significance regarding marginal microleakage, demonstrating similar performance in the proposed research situation.
O objetivo deste estudo foi avaliar o selamento de restaurações indiretas de resina cimentadas com três diferentes agentes de cimentação. Foram empregados 30 dentes bovinos onde foram realizados preparos cavitários tipo caixa no terço médio da face vestibular. As cavidades foram restauradas com resina composta indireta Resilab. Aleatoriamente, os dentes foram separados em três grupos: Grupo 1: condicionamento com ácido fosfórico a 37% por 30s, sistema adesivo Prime Bond2.1 (Dentsply) e cimento resinoso Enforce (Dentsply); Grupo 2: condicionamento com ácido fosfórico a 37% por 30s,sistema adesivo Single Bond (3M ESPE) e cimento resinoso RelyX ARC (3M ESPE) e Grupo 3: cimento de ionômerode vidro resino modificado RelyX Unicem Aplicap (3M ESPE). As peças foram cimentadas com os respectivos cimentos e os espécimes termociclados por 800 ciclos. Para avaliação de infiltração utilizou-se o corante nitrato de prata a 50 %por 24h. Os dentes foram seccionados no sentido vestíbulo-lingual em 3 fatias de 1 mm, fixados em lâmina de vidro e avaliados em estereomicroscópio, onde havia uma câmera digital acoplada e as imagens foram registradas e áreas de infiltração marginal posteriormente mensuradas pelo software Image Tool 3.0. Os dados obtidos foram submetidos aos testes estatíticos ANOVA e Tukey. ANOVA demonstrou não haver diferenças estatísticas entre os grupos (p=0,73). As médias (desvio padrão) foram: Grupo 1=0,96(±0,71); Grupo 2: 1,10(±0,63) e Grupo 3:0,99(±0,35) . Concluiu-se que os 3 agentes de cimentação apresentaram entre eles uma pequena diferença, porém não estatisticamente significante, em relação a microinfiltracão marginal, demonstrando comportamentos semelhantes diante proposição desta pesquisa
Subject(s)
Dental Cements , Dental Leakage , Dental Cavity Preparation , Dental Restoration, PermanentABSTRACT
Objetivo: Verificar a influência da opacidade de cor e tipos de aparelhos fotopolimerizadores (luz halogena X led azul) na microdureza da resina composta. Método: A resina composta Esthet-X (Dentsply), nas cores A2 e A2-O, foi inserida em uma matriz de aço-inoxidável com cavidades de 5mm de diâmetro e 2mm de profundidade e fotopolimerizadas por aparelhos; de luz halógena, XL 3000 (3M) ou de LED azul, Optilight LD II (Gnatus), por 40s. Formaram-se 8 grupos com quinze amostras cada, sendo estes divididos conforme as fontes polimerizadoras utilizadas, a área de exposição (superfície e a base) e a opacidade da resina composta empregada, perfazendo um total de 120 amostras de estudo. Estas foram armazenadas em água destilada, por 24h e embutidas em resina acrílica ativada quimicamente (RAAQ), sendo posteriormente realizados o acabamento e polimento com discos de lixa e de feltro. Realizou-se a leitura da microdureza em Microdurômetro Digital Vickers, utilizando 50g de carga por 30s de permanência. As médias das amostras foram submetidas aos testes estatísticos de análise de variância (ANOVA) e ao teste de comparação múltipla de Tukey (5%). Resultados: A microdureza da superfície foi sempre maior que a da base independente do aparelho polimerizador utilizado; o aparelho de luz halógena apresentou maiores valores médios de microdureza da resina composta (57,61HV) em relação ao aparelho de LED (42,53HV); foram encontradas diferenças significantes entre os valores médios de microdureza ao se variar a opacidade, sendo que em profundidade obteve-se os menores valores com a resina A2-O. Conclusão: A opacidade da resina, bem como, o aparelho fotopolimerizador influenciam no grau de microdureza da resina composta.