Influência de agentes antiproteolíticos na resistência de união da interface dentina, adesivo e cimento resinoso / Influence of antiproteolytic agents on dentin, adhesive and luting cement interface

O objetivo deste trabalho, foi avaliar a influência de agentes antiproteolíticos, imediatamente e após 12 meses, na cimentação adesiva. Foram utilizadas as porções coronárias de 64 molares humanos hígidos. As amostras foram divididas aleatoriamente em 4 grupos, de acordo com o tratamento da dentina: CT (grupo controle); CXL (grupo clorexidina); EGCG (grupo epigalocatequina-3-galato); AT (grupo antocianina). Para a restauração, foram confeccionados cilindros em resina composta Filtek Z350 XT. Após o condicionamento ácido da dentina, as soluções antiproteolíticas foram aplicadas e mantidas sobre a superfície por 60 s, em seguida as restaurações foram cimentadas às amostras com o adesivo Adper Single Bond 2 + cimento resinoso Variolink II. Todos os grupos foram subdivididos de acordo com o tempo de armazenamento em água destilada para o ensaio mecânico: I (Imediato = após 24 h); A (Armazenado = após 12 meses). As amostras foram cortadas em palitos e submetidas ao teste de microtração. Os dados obtidos foram submetidos ao teste de ANOVA a 2 fatores, seguido do teste de Tukey (α=5%). Foram encontradas diferenças para os fatores Tratamento (p=0,03) e Armazenamento (p=0,00). Os valores em MPa de média e desvio padrão para interação entre os fatores Tratamento X Armazenamento, foram: CT.I: 42.56 (±7,60) A; EGCG.I: 39.6 (±8,99) A; CLX.I: 39.37 (±9,44) A; AT.I: 38.69 (±8,65) A; CT.A: 31.85 (±6,96) A; AT.A: 31.29 (±4,89) AB; EGCG.A: 30.94 (±9,91) AB; CLX.A: 18.68 (±4,53) B. Foram confeccionadas duas amostras adicionais de cada grupo para avaliação descritiva da microdureza knoop de subsuperfície e avaliação qualitativa da interface adesiva em MEV. Conclui-se que as soluções de EGCG e AT foram capazes de manter a estabilidade da resistência de união após 12 meses de armazenamento e que a solução de CLX afetou negativamente os valores de resistência de união comparado aos demais subgrupos(AU)

The aim of this study was to evaluate immediately and longitunally the antiproteolytic agent influence to adhesive cementation. Were used 64 coronary portion of sound human molars. The samples were divided into 4 groups according to the dentin treatment: CG (Control group); CLX (chlorhexidine group); EGCG (epigallocatechin-3- gallate group); AT (anthocyanin group). Cylindrical composite blocks were prepared using a resin composite Filtek Supreme for the restorations. The solutions were applied on the acid-etched dentin and were kept for 60 s. The resin composite blocks were cemented with the adhesive system Adper Single Bond 2 + resin cement Variolink II. All groups were subdivided according to the storage time in distilled water for mechanical testing: I (Immediate = after 24 h); S (Stored = after 12 months). Samples were cut into beams and tested in a universal testing machine at a crosshead speed of 0.5 mm/min until failure. The data were submitted to two-way ANOVA, followed by the Tukey test (α = 5%). Significant differences were found for the Treatment factor (p = 0.03) and Storage factor (p = 0.00). The mean values and standard deviation for interaction between the factors Treatment X Storage, were CG.I: 42.56 (± 7.60) A; EGCG.I: 39.6 (± 8.99) A; CLX.I: 39.37 (± 9.44) A; AT.I: 38.69 (± 8.65) A; CG.S: 31.85 (± 6.96) A; AT.S: 31.29 (± 4.89) AB; EGCG.S: 30.94 (± 9.91) AB; CLX.S: 18.68 (± 4.53) B. Two additional samples from each group were confectioned to descriptive analyses of microhardness knoop of dentin subjacent to the bonding interface and a qualitative interface evaluation with SEM (scanning electron microscope). It can be conclude that EGCG and AT solutions were able to maintain the bond strength stability after 12 months of storage and CLX solution adversely affect the bond strength values compared to other subgroups(AU)

Effects of Different Surface Treatments on Composite Repairs.

PURPOSE: To evaluate the influence of different surface treatments on roughness and bond strength of composite repairs. MATERIALS AND METHODS: 120 truncated conical specimens were prepared with composite Grandio SO (VOCO) and submitted to 5000 thermal cycles. Specimens were divided into 12 groups (n = 10) regarding the surface treatments: negative control (NC), without treatment; medium-grit diamond bur (MGD); coarse-grit diamond bur (CGD); conventional carbide bur (ConC); crosscut carbide bur (CutC); chemical vapor deposition diamond bur (CVD); sandblasting with aluminum oxide (AlO); Er:YAG laser 200 mJ/10 Hz (Er200); Er:YAG laser 60 mJ/10 Hz (Er50); Nd:YAG laser 120 mJ/15 Hz (Nd120); Nd:YAG laser 60 mJ/ 15Hz (Nd60); air abrasion with 110-µm silica modified aluminum oxide (Rocatec Plus-3M) (SIL). After the surface treatments, the surface roughness (Ra) was measured using a profilometer, and then the adhesive system Admira Bond (VOCO) was applied. Another truncated conical restoration was built up with the same composite over the bonded area of each specimen. In order to evaluate the cohesive strength, double-cone specimens were made and considered as a control group (CoheC). The specimens were submitted to tensile bond strength testing and the obtained data (MPa) were evaluated by one-way ANOVA, Tukey's and correlation tests. RESULTS: ANOVA showed significant differences among experimental groups for roughness and adhesive strength (p < 0.00). The roughness values (Ra) were: NC (0.21 ± 0.19)(c); ConC (0.30 ± 0.08)(c); CutC (0.50 ± 0.22)(cd); CVD (0.74 ± 0.14)(bd); MGD (0.89 ± 0.39)(ab); Er50 (0.89 ± 0.14)(ab); AlO (0.90 ± 0.07)(ab); Nd60 (0.94 ± 0.33ab; SIL (0.98 ± 0.07)(ab); Nd120 (1.10 ± 0.19)(a); CGD (1.10 ± 0.32)(a); Er200 (1.12 ± 0.21)(a). The results of the tensile bond strength test in MPa were: CGD (11.58 ± 3.03)(a); MGD (12.66 ± 3.82)(ab); NC (13.51 ± 3.95(ab); Nd120 (14.11 ± 5.95)(ab); ConC (14.73 ± 6.12)(ab); Er200 (15.51 ± 1.45)(abc); CVD (15.61 ± 5.00(abc); Er50 (16.44 ± 2.75) (abc); CutC (16.79 ± 2.98)(abc); Nd60 (17.72 ± 2.45)(abcd); AlO (18.33 ± 3.19)(bcd); SIL (21.13 ± 4.48(cd); CoheC (23.50 ± 5.81)(d). The groups followed by the same letters were not statistically significantly different (Tukey's test). No correlation was found between bond strength and roughness (r = 0.007). CONCLUSION: Air abrasion with silica coating (Rocatec) was the only method which resulted in significantly higher bond strength in relation to the negative control group. The increase in laser energy produced a rougher surface, but reduced the bond strength.

Afastamento gengival: técnicas e materiais / Gingival retraction: techniques and materials

Este trabalho teve como objetivo levar o leitor a uma revisão da literatura sobre os diferentes métodos de afastamento gengival, suas técnicas, indicações e contraindicações. Foram abordadas as variações dos métodos e técnicas, a fim de facilitar a escolha mais adequada às diferentes situações clínicas. São feitas considerações sobre as soluções químicas, os fios utilizados para o afastamento gengival, as pastas adstringentes, bem como a combinação entre eles. Foram elaborados quadros comparativos entre os diferentes métodos de afastamento gengival, entre as soluções químicas mais utilizadas e entre as diferentes marcas comerciais existentes.

This paper aims to take the reader on a review of literature about the diff erent methods of gingival retraction, their techniques, indications and contraindications. Variations of the methods and techniques were discussed in order to facilitate the most appropriate choice for diff erent clinical situations. Some considerations were made about the chemical solutions, the gingival retraction cords, as well as their combination. Comparative tables among the diff erent gingival retraction methods, the most used chemical solutions, and the diff erent trademarks were prepared.

Effect of Matrix Metalloproteinase-inhibiting Solutions and Aging Methods on Dentin Bond Strength.

PURPOSE: This study examined the effects of matrix metalloproteinase-inhibiting solutions and aging methods on the bond strength between resin composite and human dentin. MATERIALS AND METHODS: Crown segments of 105 human non-carious molars were bonded using simulated pulpal pressure at 20 cm water pressure. The teeth were randomly split into 5 groups according to the solution applied: CG (control, no solution), CHX (0.2% chlorhexidine), EPE (10% ethanolic propolis extract), APE (aqueous propolis extract), and E (70% ethanol). Each solution was left on the acid-etched dentin for 1 min. Adper Single Bond 2 and resin composite (Filtek Z350 XT) were applied to all specimens. The 5 groups were subdivided according to the aging method: SI (sectioned immediately); S (storage in artificial saliva for 6 months); and T (thermomechanical aging with 240,000 mechanical cycles and 1000 thermal cycles). Specimens were sectioned into sticks and subjected to microtensile testing. Bond strength data were analyzed by two-factor ANOVA followed by a post-hoc Tukey's test (α=0.05). RESULTS: For the factor "solution", there was no significant difference among the groups (p=0.32). For the factor "aging method", significant differences were found (p<0.001), with the following mean bond strengths (MPa): SI: 31.1; S: 24.4; T: 26.8. CONCLUSIONS: The use of matrix metalloproteinase-inhibiting solutions on dentin as an adjunct to the application of an etch-and-rinse adhesive does not prevent the loss of bond strength after aging. Nevertheless, these solutions have no adverse effect on adhesion to tooth structure.

The effect of CPP-ACP and Nd:YAG laser on the bond strength of softened dentin.

The purpose of this study was to investigate the effect of CPP-ACP treatment and Nd:YAG laser on microtensile bond strength (µTBS) of softened dentin. Sixty samples were obtained from thirty sound third molars. All samples were submitted to dentin softening procedure, by the immersion of the specimens in 30 mL of Sprite Zero for 30 min. Afterwards, the samples were randomly divided according to the CPP-ACP treatment: CG-Control group; MP-treated with CPP-ACP paste (MI Paste); MPP-treated with CPP-ACP+900 ppm NaF paste (MI Paste Plus). Each group was further divided according to bonding procedure: NL-No laser; L-Laser irradiation after adhesive application and before polymerization. The laser parameters used were 1.4 W, 10 Hz, 140 mJ/pulse, with an optic fiber of 320 µm, generating energy of 174 J/cm(2) per pulse. All samples were restored with Clearfil SE Bond/Filtek Z350 XT. After 24 h, the restored samples were cut into beams (± 1 mm(2) adhesive interface area) and subjected to a µTBS test. Data were analyzed by two-way ANOVA test and Holm-Sidak post-hoc method (α = 0.05). The treatment with CPP-ACP pastes did not significantly affect softened dentin µTBS (p = 0.070). Statistic revealed significant reduction on µTBS values for CG/L, leading to the rejection of the second null hypothesis (p < 0.001). Both CPP-ACP based pastes did not affect µTBS of softened dentin for the adhesive system utilized. The Nd:YAG laser irradiation after application of adhesive system did affect µTBS values of softened dentin samples untreated with CPP-ACP based pastes.

The effect of CPP-ACP and Nd:YAG laser on the bond strength of softened dentin

The purpose of this study was to investigate the effect of CPP-ACP treatment and Nd:YAG laser on microtensile bond strength (µTBS) of softened dentin. Sixty samples were obtained from thirty sound third molars. All samples were submitted to dentin softening procedure, by the immersion of the specimens in 30 mL of Sprite Zero for 30min. Afterwards, the samples were randomly divided according to the CPP-ACP treatment: CG-Control group; MP-treated with CPP-ACP paste (MI Paste); MPP-treated with CPP-ACP+900 ppm NaF paste (MI Paste Plus). Each group was further divided according to bonding procedure: NL-No laser; L–Laser irradiation after adhesive application and before polymerization. The laser parameters used were 1.4 W, 10 Hz, 140 mJ/pulse, with an optic fiber of 320 µm, generating energy of 174 J/cm2 per pulse. All samples were restored with Clearfil SE Bond/Filtek Z350 XT. After 24 h, the restored samples were cut into beams (± 1 mm2adhesive interface area) and subjected to a µTBS test. Data were analyzed by two-way ANOVA test and Holm-Sidak post-hoc method (α = 0.05). The treatment with CPP-ACP pastes did not significantly affect softened dentin µTBS (p = 0.070). Statistic revealed significant reduction on µTBS values for CG/L, leading to the rejection of the second null hypothesis (p < 0.001). Both CPP-ACP based pastes did not affect µTBS of softened dentin for the adhesive system utilized. The Nd:YAG laser irradiation after application of adhesive system did affect µTBS values of softened dentin samples untreated with CPP-ACP based pastes.

A split-mouth randomized clinical trial of conventional and heavy flowable composites in class II restorations.

OBJECTIVE: The aim of this study was to evaluate the 2-year clinical performance of class II restorations made with a composite resin with two different viscosities. METHODS: 47 patients received two class II restorations (n=94), one made with GrandioSO (conventional viscosity - CV), and the other with GrandioSO Heavy Flow (flowable viscosity - FV), subjecting both materials to the same clinical conditions. The self-etching adhesive Futurabond M was used for all restorations. The composites were inserted using the incremental technique. The restorations were evaluated using the modified USPHS criteria according to the periods: baseline, 6 months, 1 year and 2 years after restorative procedures. RESULTS: After 24 months, 40 patients attended the recall and 78 restorations were evaluated. In all periods, no secondary caries was observed. After 6 months, there were slightly overall changes of scores for most parameters. After 24 months, the higher number of changes from score Alfa to Bravo was observed for marginal discolouration (32.5% - CV and 39.5% - FV) and colour match (15% - CV and 31.6% - FV), followed by proximal contact (25% - CV and 23.7% - FV) and marginal adaptation (20% - CV and 21.1% - FV). For wear, surface texture and postoperative sensitivity the changes were very small. Just two restorations were lost during the 24-month follow up. Less than 5% of all restorations showed postoperative sensitivity. Chi-square test showed no significant differences between the two materials for all parameters analysed. CONCLUSION: After 2 years of clinical service, no significant differences were observed between GrandioSO conventional and GrandioSO Heavy Flow for the parameters analysed. Both materials provided acceptable clinical behaviour in class II restorations. CLINICAL SIGNIFICANCE: This study presents the possibility of using a flowable composite with high filler content, for performing class II restorations.

Avaliação da liberação de íon fluoreto de cimentos ionoméricos antes e após a recarga e com proteção da superfície / Fluoride ion release from glass ionomer cements before and after recharge and surface protection

Objetivo: Avaliar a liberação de íon fluoreto de 2 cimentos de ionômerode vidro (CIV) anidro e 2 modificados por resina composta antes e apósrecarga com fluoreto de sódio neutro a 2% por 4min. e após a proteçãoda superfície do CIV Maxxion R com um adesivo odontológico, umverniz cavitário e um esmalte incolor para unhas.Métodos: Com uma matriz de aço inox com 2mm x 6mm,confeccionou-se 5 corpos de prova de cada material, que foramimersos em 5mL de água deionizada, trocada a cada 24h. Foramrealizadas leituras em um potenciômetro nos dias 1, 2, 9 e 17 na 1ª e 2ªetapas, e as amostras foram tamponadas com solução TISAB III. Na 2ªetapa, as amostras foram submetidas à recarga e novamente imersasem 5mL de água deionizada. Na 3ª etapa foi realizada a proteção dasuperfície dos CIVs e feitas leituras nos 5min., 24h, 48h e 72h. Utilizouseos testes estatísticos Post Hoc de Tukey e t Student (p<0,05).Resultados: Observou-se diferença estatisticamente significante aocomparar a 1ª com a 2ª etapas em todos os materiais, exceto no dia 2para o Vidrion R e para o VitroFil LC. Na 3ª etapa observou-se que emtodos os materiais, comparando os primeiros 5 min. com os outrostempos, as diferenças entre as médias da liberação das concentraçõesde íon fluoreto foram estatisticamente significantes. Ao 0comparar osdemais tempos, tanto o verniz quanto o esmalte incolor para unhasapresentou diferença estatisticamente significante entre 24h e 48h,bem como em 24h e 72h.Conclusão: Os CIVs anidros tiveram maior efetividade na liberação deíon fluoreto e na recarga em comparação com os CIVs modificados porresina composta e o Maxxion R apresentou um comportamentohomogêneo e estatisticamente significante nas duas etapas. Todos osmateriais protetores testados foram eficazes, e o esmalte incolor paraunhas apresentou o melhor comportamento...

Objective: To evaluate fluoride ion release from two anhydrous glassionomer cements (GICs) and two resin-modified GICs (RMGICs) before and after recharge with 2% neutral sodium fluoride for 4 min and after surface protection of the Maxxion R GIC with an adhesive system, a cavity varnish and a colorless nail polish. Method: A stainless steel 2x6 mm matrix was used for fabricating 5 specimens of each material, which were immersed in 5 mL of deionized water, renewed every 24 h. Measurements with a potentiometer were performed on days 1, 2, 9 and 17, in the 1st and 2nd phases, and thespecimens were buffered with a TISAB III solution. In the 2nd phase, thespecimens were subjected to recharge and immersed again in 5 mL ofdeionized water. In the 3rd phase, the GIC surfaces were protected andreadings were made at 5 min, 24 h, 48 h and 72 h. TukeyÆs post-hoc and StudentÆs t tests were used for statistical analyses (p<0.05). Results: There was statistically significant difference in the comparison between the 1st and 2nd phases for all materials, except at day 2 for Vidrion R and VitroFil LC. In the 3rd phase, it was observed that for all materials, comparison of the first 5 min with the other times revealedstatistically significant differences among the means of fluoride ionrelease. In the comparison with the other times, both the varnish and the colorless nail polish presented statistically significant differencebetween 24 and 48 h as well as between 24 and 72 h. Conclusion: The anhydrous GICs were more effective in fluoride ion release and recharge compared with the RMGICs. Maxxion R presented a homogeneous and statistically significant behavior in both phases. All materials for surface protection were efficient and the colorless nail polish had the best behavior...

Avaliação da resistência de união em dentina submetida ao desafio erosivo: adesão ao substrato tratado com CPP-ACP e irradiado ou não com laser Nd:YAG / Evaluation of dentin bond strength under erosive challenge: adhesion to substrate treated with CPP-ACP and Nd:YAG irradiated

O estudo avaliou a influência do CCP-ACP (casein phosphopeptide – amorphous calcium phosphate) e CPP-ACP associado ao NaF, na resistência de união à dentina submetida ao desafio erosivo por bebida ácida, com ou sem irradiação por laser Nd:YAG. Foram utilizados 60 molares humanos, os quais tiveram a porção coronária seccionada mesio-distalmente, obtendo dois espécimes. Após a exposição da dentina, os espécimes foram embutidos em resina acrílica quimicamente ativada. Quatro grupos (n=30) foram obtidos: GC (grupo controle); DE (desafio erosivo); DE.M (desafio erosivo + MI Paste); DE.MP (desafio erosivo + MI Paste Plus). O desafio erosivo foi realizado pela imersão única das amostras em Sprite Zero, durante 30 min. Os grupos DE.M e DE.MP foram submetidos ao tratamento remineralizador com a aplicação de uma camada de aproximadamente 0,5mm por 3 min. Os grupos foram divididos em dois subgrupos: SL (sem laser Nd:YAG) e CL (sistema adesivo + laser Nd:YAG + fotopolimerização). A densidade de energia utilizada foi 174J/cm2, 140 mJ/pulsos, 10 Hz, 1,4W. Todos os espécimes foram restaurados com o sistema adesivo Clearfil SE Bond (Kuraray) e a resina composta Z350XT (3M-ESPE). Após 24h de armazenagem em água deionizada, os espécimes foram cortados em palitos, com secção transversal de 1mm2 de área e em seguida foi realizado o ensaio de microtração. Os dados foram submetidos à ANOVA 2 fatores e foram encontradas diferenças estatísticamente significantes para o fator tratamento (p=0,00). O grupo DE foi o que apresentou menor valor de resistência adesiva após o teste de Tukey. As médias de todos os grupos, em ordem crescente, foram: DE.CL (29,22) < DE.SL (33,50) < DE.M.SL (33,89) < DE.MP.SL (34,96) < GC.SL (36,40) < DE.MP.CL (36,92) < GC.CL (37,46) < DE.M.CL (37,68). Concluiu-se que: o desafio erosivo proposto resultou na diminuição da resistência de união quando comparado ao grupo controle; O CPP-ACP e o CPP-ACP associado ao NaF promoveram o aumento da resistência de ...

The purpose of this study was to evaluate the influence of CPP-ACP (MI Paste) and CPP-ACP associated to NaF (MI Paste Plus) on microtensile bond strength of dentin softened by a soft drink, irradiated or not with laser Nd:YAG. Sixty human molars had their crowns sectioned from mesial to distal face in order to obtain two specimens. The enamel was flattened until the exposure of 3 mm dentin area and then were embedded in acrylic resin. The samples were randomly divided into four groups (n=30): CG (control group); EC (erosive challenge); EC.M (erosive challenge + MI Paste); EC.MP (erosive challenge + MI Paste Plus). The erosive challenge consisted by a single immersion of the specimens in Sprite Zero, for 30 min. The EC.M and EC.MP were submitted to remineralizing treatment with the application of a 0,5 mm layer, for 3 min. The groups were subdivided into two subgroups: WITH (WL) or WITHOUT (W) Nd:YAG laser application. Laser application was made by the energy density of 174J/cm2, 140 mJ/pulse, 10 Hz, 1.4W, and the sequence was: adhesive system + Nd:YAG laser + photopolimerization. All the samples were restored by the adhesive system Clearfil SE Bond (Kuraray) and the composite Z350XT (3M-ESPE). After 24h storage in deionized water, the samples were cut in sticks, with 1mm2 cross-section area, then was accomplished the microtensile test. The microtensile data were analyzed with two-way ANOVA. Significant statistically differences were found to the treatment factor (p=0.00) and Tukey test showed that the EC group presented lower values to microtensile bond strength. The averages of each group, in ascending order, were: EC.WL (29.22) < EC.W (33.50) < EC.M.W (33.89) < EC.MP.W (34.96) < CG.W (36.40) < EC.MP.WL (36.92) < CG.WL (37.46) < EC.M.WL (37.68). It was concluded that: the erosive challenge decreased the bond strength compared to control group; the CPP-ACP and CPP-ACP associated to NaF increased the bond strength4 compared to the groups which had not ...