Mechanical-physicochemical properties and biocompatibility of catechin-incorporated adhesive resins

Several anti-proteolytic dentin therapies are being exhaustively studied in an attempt to reduce dentin bond degradation and improve clinical performance and longevity of adhesive restorations. Objectives: This study assessed the effect of epigallocatechin-3-gallate (EGCG) on long-term bond strength when incorporated into adhesives. Material and Methods: Adhesive systems were formulated with EGCG concentrations of 0 wt%: (no EGCG; control); 0.5 wt% EGCG; 1.0 wt% EGCG, and 1.5 wt% EGCG. Flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), compressive strength (CS), degree of conversion (DC), polymerization shrinkage (PS), percentage of water sorption (%WS), percentage of water solubility (%WL) and cytotoxicity properties were tested. Dentin microtensile bond strength (µTBS) was evaluated after 24 h and again after 6 months of water storage. The adhesive interface was analyzed using scanning electron microscopy (SEM). Results: No significant differences were found among the groups in terms of FS, ME, MR, CS and PS. EGCG-doped adhesives increased the DC relative to the control group. EGCG concentrations of 1.0 wt% and 0.5 wt% decreased the WS of adhesives. WL decreased in all cases in which EGCG was added to adhesives, regardless of the concentration. EGCG concentrations of 1.0 wt% and 0.5 wt% reduced cytotoxicity. EGCG concentrations of 1.0 wt% and 0.5 wt% preserved µTBS after 6 months of storage, while 1.5 wt% EGCG significantly decreased µTBS. SEM: the integrity of the hybrid layer was maintained in the 0.5 wt% and 1.0 wt% EGCG groups. Conclusion: EGCG concentrations of 1.0 wt% and 0.5 wt% showed better biological and mechanical performance, preserved bond strength and adhesive interface, and reduced cytotoxicity

Estudo longitudinal da resistência adesiva aos substratos dentários de sistemas adesivos associados ou não ao Nd:YAG Laser

O objetivo deste estudo foi avaliar a resistência de união dos sistemas adesivos Clearfil SE Bond (CL) e Single Bond (SB) ao esmalte e dentina, em função da associação ou não do Nd:YAG Laser e do tempo de armazenagem (24 h e 12 meses). Foram utilizados 240 dentes bovinos com superfícies de esmalte ou dentina planificadas, que foram divididos em 4 grupos (n = 15) para cada substrato, de acordo com o sistema adesivo e a técnica: G1 (Controle) - CL + fotopolimerização; G2 (Controle) - SB + fotopolimerização; G3 (Experimental/Laser) - CL + Nd:YAG Laser + fotopolimerização; G4 (Experimental/Laser) - SB + Nd:YAG Laser + fotopolimerização. Para o esmalte, foi utilizada a densidade de energia = 174,16 J/cm2 e, para a dentina, a densidade de energia = 149,28 J/cm2 do Nd:YAG Laser. Foram confeccionadas restaurações de resina composta Z-350. Após armazenagem de 24 h ou 12 meses em água destilada à 37º C, foram realizadas as secções nos dentes para obtenção de amostras com área adesiva de aproximadamente 1 mm2, seguido de teste de microtração. Para cada substrato, foi realizado o teste estatístico ANOVA três fatores (Sistema adesivo X Técnica X Tempo de armazenagem), seguido do Teste de Tukey (α = 5%). Foi realizada MEV para análise complementar da interface adesiva. Para o esmalte, foram observadas diferenças significantes para a interação entre Tipo de adesivo X Técnica e Técnica X Tempo de armazenagem. Os valores de média em MPa (±Desvio-padrão) para a interação entre Tipo de adesivo X Técnica: SB/Controle = 35,78 (± 6,04)a; SB/Laser = 26,40 (± 7,25)b; CL/Controle = 26,32 (± 5,71)b; CL/Laser = 23,90 (± 7,49)b. Os valores de média em MPa (±Desvio-padrão) para a interação entre Técnica X Tempo de armazenagem: Controle/24h = 32,58 (± 6,49)a; Controle/12 meses = 29,52 (± 8,38)a; Laser/24h = 29,37 (± 5,71)a; Laser/12 meses = 20,92 (± 6,5)b. Para...The aim of this study was to evaluate the bond strength of Clearfil SE Bond (CL) and Single Bond (SB) adhesive systems to enamel and dentin, depending on whether association with Nd: YAG Laser and storage time (24 h and 12 months). A total of 240 bovine teeth with enamel or dentin surfaces planned were prepared, which were divided into 4 groups (n = 15) for each substrate, according to the adhesive system and technique: G1 (control) - CL + photopolymerization; G2 (Control) - SB + photopolymerization; G3 (Experimental/Laser) - CL + Nd: YAG Laser + photopolymerization; G4 (Experimental/Laser) - SB + Nd: YAG Laser + photopolymerization. To the enamel, was used energy density = 174.16 J/cm2 and for dentine, energy density = 149.28 J/cm2 of Nd: YAG Laser. Composite restorations were fabricated (Filtek Z-350). After storage for 24 h or 12 months in distilled water at 37 ° C, the sections were performed on teeth to obtainment sticks with an area of about 1 mm2 adhesive interface, followed by microtensile test. For each substrate, we performed a three-way ANOVA (adhesive X Technical X Storage time), followed by the Tukey test (α = 5%). SEM analysis was performed to supplement the adhesive interface. For enamel, significant differences were observed for interaction factors Adhesive X Technique and Technique X Storage time. The mean values in MPa (± standard deviation) for interaction factor Adhesive X Technique: SB / Control = 35.78 (± 6.04) a; SB / Laser = 26.40 (± 7.25) b, CL / Control = 26.32 (± 5.71) b, CL / Laser = 23.90 (± 7.49) b. The mean values in MPa (± standard deviation) for interaction factor Technique X Storage time: Control/24h = 32.58 (± 6.49)a; Control/12 months = 29.52 (± 8.38 )a; Laser/24h = 29.37 (± 5.71)a; Laser/12 months = 20.92 (± 6.5)b. For dentin, significant differences were observed for interaction factors Technique X Storage time and Adhesive X Technique ..

Prevalência do lado preferencial mastigatório e sua relação com a alimentação, a saúde periodontal, o lado preferencial no primeiro ciclo mastigatório e a dominância lateral nas dentições decídua, mista e permanente

Esse estudo de prevalência objetivou avaliar o lado preferencial mastigatório nas dentições decídua, mista e permanente e sua relação com: a consistência da dieta alimentar; o índice de placa e o índice gengival entre as hemi-arcadas direita e esquerda; o lado preferencial no primeiro ciclo mastigatório e as dominâncias laterais. Foram avaliados 300 indivíduos divididos em três grupos: Grupo 1 - 100 indivíduos entre 3 e 5 anos de idade com dentição decídua; Grupo 2 - 100 indivíduos entre 6 e 12 anos de idade com dentição mista; Grupo 3 - 100 indivíduos a partir de 18 anos de idade com dentição permanente. Foram coletados dados sobre a consistência alimentar (sólido, semi-sólido, pastoso e líquido) dos indivíduos. Foi realizado o índice gengival segundo o critério de Löe e Silness (1963) e o índice de placa segundo os critérios de Greene e Vermilion (1964) entre as hemi-arcadas direitas e esquerdas. Foi realizado o teste midificado de Mc Donnell et al. (2004) para determinar o lado preferencial mastigatório e o teste desenvolvido por Hoogmartens e Caubergh (1987a) para determinar o lado preferencial no primeiro ciclo mastigatório. Foi realizado o teste desenvolvido por Porac e Coren (1981) para determinar a dominância lateral das mãos, pés, olhos e ouvidos. Foi utilizada estatística descritiva para observar a prevalência do lado preferencial mastigatório, o teste Qui-quadrado e o teste Z para a relação entre os dados obtidos. Pode-se observar uma prevalência do lado preferencial mastigatório de 87% para o grupo 1, de 82% para o grupo 2 e de 76% para o grupo 3. O teste qui-quadrado demonstrou haver relação significante entre o lado preferencial mastigatório e: o lado preferencial no 9 primeiro ciclo mastigatório para os grupos 1, 2 e 3; a dominância lateral dos ouvidos para o grupo 1; e as dominâncias laterais das mãos e dos pés para grupos...This study evaluated the prevalence of chewing side preference in deciduous, mixed and permanent dentition and its relationship with: food consistency, gingival and plaque index between the left and right hemiarcades, the side preference at first chewing and lateral dominance. It was evaluated 300 subjects divided into three groups: Group 1 - 100 individuals between 3 and 5 years old with deciduous dentition; Group 2 - 100 individuals between 6 and 12 years old with mixed dentition; 3 - 100 individuals between 18 and 47 years old with permanent dentition. Data of food consistency were obtained with a questionnaire (solid, semi-solid, paste and liquid). The plaque index was performed according to Greene and Vermilion (1964) criteria and the gingival index was performed according to Löe e Silness (1963) criteria, for the left and right hemiarcades. To determine the chewing side preference, was used the test developed by Christensen and Radue (1985a). To determine the side preference at first chewing, was used the test developed by Hoogmartens and Caubergh (1987a). To determine the lateral dominance of the hands, feet, eyes and ears, was used the test developed by Porac and Coren (1981). Descriptive statistics was used to observe the prevalence of the chewing side preference. The chi-square test and Wilcoxon test and Z-test were used for the relation between the data obtained. It can be observe the prevalence of the chewing side preference: 87% for group 1, 82% for group 2 and 76% for group 3. The chi-square test showed that there was significant relation between chewing side preference and: side preference at first chewing for the deciduous, mixed and permanent dentition; ear lateral dominance for the primary dentition; hand and feet lateral dominances for the mixed and permanent dentitions. It can be concluded that the side preference at first chewing is directly related to the chewing... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Effects of Resinous Monomers Used in Restorative Dental Modeling on the Cohesive Strength of Composite Resin

Purpose: The purpose of this study was to evaluate the cohesive strength of the composite using different resinous monomers to lubricate instruments used in the Restorative Dental Modeling Insertion Technique (RDMIT).Materials and Methods: The composite specimens were made by using a prefabricated Teflon device. Different resinous monomers were used at the interface to lubricate the instruments, for a total of 72 specimens divided into 6 groups: 1. control group, no resinous monomer was used; 2. Composite Wetting Resin; 3. C & B Liquid; 4. Scotchbond Multi-Purpose Adhesive; 4. Adper Single Bond Adhesive; 6. Prime & Bond NT. Specimens were submitted to the circular area tensile test to evaluate the cohesive strength at the composite interfaces. Data were analyzed using ANOVA and Tukey's test (alpha = 0.05).Results: ANOVA showed a value of p < 0.0001, which indicated that there were significant differences among the groups. The means (SD) for the different groups were: Adper Single Bond Adhesive: 26 (12) a; control group: 28 (3) ab; Prime & Bond NT: 32 (12) ab; Composite Wetting Resin: 36 (9) abc; C&B Liquid: 38 (7) bc; Scotchbond Multi-Purpose Adhesive: 46 (10) c. Groups denoted with the same letters were not significantly different. Only Scotchbond Multi-Purpose Adhesive, used for direct restorations, had a statistically significantly higher bond strength than the control group, Adper Single Bond Adhesive, and Prime & Bond NT. Adper Single Bond with Adhesive showed a statistically significantly lower mean value than C & B Liquid.Conclusion: The results of this study indicate that the resinous monomers used for lubricating the instruments in the RDMIT did not alter the mechanical properties of the composite, and therefore did not reduce the cohesive bond strength at the composite interfaces

Effects of Self-Etching Adhesive Systems Used in the Dental Modelling Technique on the Cohesive Strength of Composite Resin

This study evaluated the cohesive strength of composite using self-etching adhesive systems (SE) in the lubrication of instruments between layers of composite. The specimens were made by using a Teflon (R) device. SE were used at the interface to lubricate the instruments: Group 1(G1) - control group, no lubricant was used; Group 2(G2) -Futurabond (R) M; Group 3(G3) - Optibond (R) All-In-One; Group 4(G4) - Clearfil (R) SE Bond; Group 5(G5) - Futurabond (R) NR; Group 6(G6) - Adper (R) SE Plus; Group 7(G7) - One Up Bond (R) F. Specimens were submitted to the tensile test to evaluate the cohesive strength. Data were submitted to the ANOVA and Tukey tests. ANOVA showed a value of p = 0.00. The average means (SD): G2 = 11.33(+/-3.44) a, G3 = 15.36(+/-4.06) ab, G4 = 18.9(+/-4.72) bc, G7 = 19.62(+/-4.46) bc, G5 = 21.02(+/-5.09) bc, G6 = 23.39(+/-4.17) cd, and G1 = 28.49(+/-2.89) d. All SE decreased the cohesive strength of the composite, except for Adper (R) SE Plus