ABSTRACT
PURPOSE: To evaluate the effect of different concentrations of ethylene-diamine-tetra acetic acid (EDTA) on bond strength (BS) and nanoleakage (NL) of fiber posts bonded into root canals. MATERIALS AND METHODS: Seventy-two single roots were endodontically treated and divided into six groups (n = 12), according to the combination of the following factors: surface treatment (no irrigation [control], 17% EDTA, or 24% EDTA), and composite cement applied with an adhesive used in a self-etch mode (Single Bond Universal/RelyX Ultimate [SB], 3M Oral Care; Ambar Universal/Allcem [AM], FGM). After fiber post cementation, six 1-mm-thick disks were obtained for each root. Push-out bond strength (BS) was evaluated using 8 specimens per group, and the other 4 specimens were used to examine nanoleakage (NL). Data from BS and NL of each adhesive were evaluated by two-way ANOVA (surface treatment vs root region) and Tukey's test (α = 0.05). RESULTS: The application of 17% and 24% EDTA did not influence the bond strengths of either adhesive. In general, the application of 17% and 24% EDTA increased NL values for both adhesives. CONCLUSION: Pre-treatment with different concentrations of EDTA was not able to improve the adhesion of fiber posts into root canals with universal adhesives..
Subject(s)
Dental Bonding , Post and Core Technique , Dental Cements , Dental Pulp Cavity , Dentin , Edetic Acid , Materials Testing , Resin CementsABSTRACT
Abstract The purpose of this study was to analyze the effect of the application of different concentrations of EDTA on the adhesion of fiber posts to root dentin using self-adhesive resin cements. After endodontic treatment, 78 single roots were randomly divided into six groups (n = 13) according to the combination of the following factors: surface dentin treatment - control (distilled water), 17% EDTA and 24% EDTA; and self-adhesive resin cement - RelyX U200 (RX); and Multilink Speed (ML). After fiber post cementation, six slices were obtained for each root. Ten roots of each group were used for bond strength (BS) and three for microhardness (MH) evaluations. Data obtained from BS and MH tests for each resin cement were subjected to two-way ANOVA (surface treatment vs. root region) and to a post-hoc Tukey's test (α = 0.05). The lowest BS value was observed in the 24% EDTA group for RX cement, whereas the highest values for ML cement were observed for the control group in the middle and apical regions. In the MH test, the lowest value for RX was observed for 24% EDTA in the cervical region, whereas and the highest value for the ML cement was observed in the control group. Regarding both self-adhesive resin cements tested, the application of 24% EDTA was not able to improve the adhesion of fiber posts to root canal.
Subject(s)
Resin Cements , Materials Testing , Post and Core Technique , Edetic Acid/pharmacology , Dental Pulp Cavity , Dentin , GlassABSTRACT
The purpose of this study was to analyze the effect of the application of different concentrations of EDTA on the adhesion of fiber posts to root dentin using self-adhesive resin cements. After endodontic treatment, 78 single roots were randomly divided into six groups (n = 13) according to the combination of the following factors: surface dentin treatment - control (distilled water), 17% EDTA and 24% EDTA; and self-adhesive resin cement - RelyX U200 (RX); and Multilink Speed (ML). After fiber post cementation, six slices were obtained for each root. Ten roots of each group were used for bond strength (BS) and three for microhardness (MH) evaluations. Data obtained from BS and MH tests for each resin cement were subjected to two-way ANOVA (surface treatment vs. root region) and to a post-hoc Tukey's test (α = 0.05). The lowest BS value was observed in the 24% EDTA group for RX cement, whereas the highest values for ML cement were observed for the control group in the middle and apical regions. In the MH test, the lowest value for RX was observed for 24% EDTA in the cervical region, whereas and the highest value for the ML cement was observed in the control group. Regarding both self-adhesive resin cements tested, the application of 24% EDTA was not able to improve the adhesion of fiber posts to root canal.
Subject(s)
Resin Cements , Dental Pulp Cavity , Dentin , Edetic Acid/pharmacology , Glass , Materials Testing , Post and Core TechniqueABSTRACT
Aim: The roughness and micromorphology of various surface treatments in aged metal-free crowns and the bond strength of these crowns repaired with composite resin (CR) was evaluated in vitro. Methods: A CR core build-up was confectioned in 60 premolars and prepared for metal-free crowns. Prepared teeth were molded with the addition of silicone, and the laboratory ceromer/fiber-reinforced crowns (SR Adoro/Fibrex Lab) were fabricated. Subsequently, the crowns were cemented and artificially aged in a mechanical fatigue device (1.2 X 106 cycles), then divided into 4 groups (n = 15) according to the surface treatment: 1) phosphoric acid etching (PA); 2) PA + silane application; 3) roughening with a diamond bur + PA; and 4) sandblasting with Al2O3 + PA. After the treatments, the crowns (n = 2) were qualitatively analyzed by scanning electron microscope (SEM) and surface roughness (n = 5) was analyzed before and after the surface treatment (Ra parameter). The remaining crowns (n = 8) received standard repair with an adhesive system (Tetric N-Bond) and a nanohybrid CR (Tetric N-Ceram), and the microshear bond strength (SBS) test was performed (0.5 mm/min). Roughness and SBS data were analyzed by one- and two-way ANOVA, respectively, as well as Tukey's post-test (α = 0.05). Results: Sandblasting with Al2O3 + PA resulted in the highest final roughness and SBS values. The lowest results were observed in the PA group, whereas the silane and diamond bur groups showed intermediate values. Conclusion: It may be concluded that indirect ceromer crowns sandblasted with aluminum oxide prior to PA etching promote increased roughness surface and bond strength values
Subject(s)
Surface Properties , Ceramics , Composite Resins , Shear Strength , Electron Microscope TomographyABSTRACT
STATEMENT OF PROBLEM: Preparation of coronal dentin by using a diamond rotary instrument usually results in higher bond strength values than preparation with tungsten carbide burs, but information is lacking about the influence of rotary instruments on root canals before the bonding of fiber posts. PURPOSE: The purpose of this in vitro study was to evaluate the influence of the rotary instrument used to prepare the root canal and bonding strategies on the adhesion of fiber posts to root dentin with universal adhesive systems. MATERIAL AND METHODS: Human premolars were used and divided into 8 groups according to the combination of the following factors: rotary instrument (tungsten carbide bur versus diamond rotary instrument), cementation system (single-bond versus prime and bond), and bonding method (etch-and-rinse versus self-etch). Eight teeth per group were evaluated by push-out bond strength, 4 teeth were evaluated for nanoleakage by using scanning electron microscopy (SEM), and 2 teeth were evaluated for shape by SEM. Data for bond strength and nanoleakage for each cementation system were subjected to 2-way ANOVA and Tukey honest significant differences tests (α=.05). RESULTS: The highest bond strength values were observed for preparation using a diamond rotary instrument for both cementation systems. For prime and bond, the highest bond strength values were observed with the self-etch adhesion strategy, and the self-etch strategy was better for the single-bond; and the self-etch strategy was better than etch-and-rinse just after the use of a diamond instrument. In relation to nanoleakage for the cementation system, the prime and bond had the lowest values for groups using a diamond instrument and self-etch strategy. For the single bond, the adhesion strategy did not influence nanoleakage, but the rotary instrument did, with diamond rotary instruments resulting in lower values. SEM analyses showed a greater number of unobliterated tubules in the self-etch mode and a more regular surface when prepared with a diamond rotary. CONCLUSIONS: To improve the adhesion of fiber posts to root canal, a diamond rotary instrument should be used, and generally, universal adhesive systems must be used in self-etch mode.
Subject(s)
Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Post and Core Technique , Root Canal Preparation/instrumentation , Bicuspid , Bisphenol A-Glycidyl Methacrylate , Diamond , Equipment Design , Humans , In Vitro Techniques , Materials Testing , Microscopy, Electron, Scanning , Polyethylene Glycols , Polymethacrylic Acids , Resin CementsABSTRACT
The aim of this study was to compare in vitro the bond strength (BS) between fiberglass posts and flared root canals reinforced with different materials. The roots of 48 premolars were endodontically treated. After one week, the root canals were prepared to simulate an oversized root canal, except for the positive control group (PCG), which was cemented with a prefabricated fiber post (PFP) compatible with the root canal size, simulating an ideal adaptation. The other samples (n=8/group) were used to test alternative restorative techniques for filling root canals: negative control group (NCG [PFP with a smaller diameter than of the root canal]), composite resin group - CRG, bulkfill group - BFG, self-adhesive cement group - SAG, and glass ionomer group - GIG. The posts were cemented and after 1 week, each root was sectioned transversely into six 1-mm thick discs and the push-out test was done to evaluate the BS. Data were analyzed by two-way repeated measures ANOVA and Tukey's tests (α=0.05). The highest BS value was observed for PCG. The NCG and the GIG groups showed the lowest BS values. Root reinforcement with conventional and bulk-fill composite resins showed the highest BS values; however, the bulk-fill resin was the only treatment able to maintain high BS values in all regions of the root canal. The self-adhesive cement showed intermediate results between CRG and GIG. Root reinforcement with bulk-fill composite resin is an effective option for flared root canals before cementation of a prefabricated fiber post.
Subject(s)
Dental Bonding/methods , Dental Materials/chemistry , Dental Pulp Cavity/drug effects , Glass/chemistry , Post and Core Technique , Root Canal Preparation/methods , Analysis of Variance , Dental Pulp Cavity/anatomy & histology , Dental Restoration Failure , Humans , Materials Testing , Reference Values , Reproducibility of Results , Time FactorsABSTRACT
Abstract The aim of this study was to compare in vitro the bond strength (BS) between fiberglass posts and flared root canals reinforced with different materials. The roots of 48 premolars were endodontically treated. After one week, the root canals were prepared to simulate an oversized root canal, except for the positive control group (PCG), which was cemented with a prefabricated fiber post (PFP) compatible with the root canal size, simulating an ideal adaptation. The other samples (n=8/group) were used to test alternative restorative techniques for filling root canals: negative control group (NCG [PFP with a smaller diameter than of the root canal]), composite resin group - CRG, bulkfill group - BFG, self-adhesive cement group - SAG, and glass ionomer group - GIG. The posts were cemented and after 1 week, each root was sectioned transversely into six 1-mm thick discs and the push-out test was done to evaluate the BS. Data were analyzed by two-way repeated measures ANOVA and Tukey's tests (α=0.05). The highest BS value was observed for PCG. The NCG and the GIG groups showed the lowest BS values. Root reinforcement with conventional and bulk-fill composite resins showed the highest BS values; however, the bulk-fill resin was the only treatment able to maintain high BS values in all regions of the root canal. The self-adhesive cement showed intermediate results between CRG and GIG. Root reinforcement with bulk-fill composite resin is an effective option for flared root canals before cementation of a prefabricated fiber post.
Subject(s)
Humans , Dental Bonding/methods , Dental Materials/chemistry , Dental Pulp Cavity/drug effects , Glass/chemistry , Post and Core Technique , Root Canal Preparation/methods , Analysis of Variance , Dental Pulp Cavity/anatomy & histology , Dental Restoration Failure , Materials Testing , Reference Values , Reproducibility of Results , Time FactorsABSTRACT
PURPOSE: To evaluate the effect of dentin moisture and application mode of universal adhesives on bond strength (BS) and nanoleakage (NL) of fiber posts bonded to root dentin. MATERIALS AND METHODS: The roots of 96 extracted human canines were treated endodontically, and the fiber posts were cemented according to the combination of the following factors: dentin moisture (dry and wet), cementation system [Single Bond Universal/RelyX ARC (SBU) and Prime&Bond elect/Enforce (PBE)], and adhesive application [active (A) and passive (P)] in accordance with the manufacturer's instructions. After one week, the specimens were transversely sectioned into six 1-mm-thick disks. From each group, 8 specimens were subjected to the push-out BS test and the other 4 specimens underwent NL analysis. For both tests, the data were subjected to 3-way repeated measures ANOVA and Tukey's tests (α = 0.05). RESULTS: For BS and NL, the cross-product interaction of all factors was significant (p < 0.05). Lower BS was observed under P application independent of the dentin moisture; for A application, SBU showed higher BS than did PBE in both moisture conditions. Nanoleakage was present in all groups and ranged from 22.9% to 36%. CONCLUSION: The active application of universal adhesives improves the adhesion in fiber post cementation, independent of dentin moisture condition.
Subject(s)
Dentin-Bonding Agents , Post and Core Technique , Dental Bonding , Dental Cements , Dental Pulp Cavity , Dentin , Glass , Humans , Materials Testing , Resin CementsABSTRACT
Objetivo: Avaliar a liberação e a capacidade de recarga de flúor de diferentes cimentos de ionômero de vidro, durante a simulação de desafio cariogênico. Material e método: Foram confeccionados 12 corpos de prova para cada grupo experimental, com cimentos de ionômero de vidro convencionais - Maxxion R (FGM), Ketac Molar EasyMix (3M ESPE); cimento de ionômero de vidro modificado por resina - Vitrebond (3M ESPE), e resina composta, Filtek™ Z350XT (3M ESPE), como controle negativo. Os corpos de prova foram imersos alternadamente em sistema de ciclagem de pH, permanecendo 6 horas na solução de desmineralização e 18 horas na de remineralização, sendo mantidos em estufa a 37°C. Liberação de flúor foi verificada 1, 2, 7 e 14 dias antes e após a recarga com flúor, com eletrodo específico acoplado ao aparelho analisador de pH/fluoretos, calibrado a cada medição com soluções de fluoreto de sódio a 1 e 10 ppm, preparadas com TISAB II. Para leitura, foi adicionado 0,5 mL da amostra a igual volume de TISAB II. Recarga foi realizada com flúor neutro 2% por 4 minutos nas amostras, lavadas e imersas novamente nas soluções do sistema de ciclagem de pH. Os dados foram submetidos à análise de variância e ao teste de Tukey (α=0,05). Resultado: A liberação inicial de fluoreto (µgF/cm2) foi de 45,36; 37,49, e 26,35 para Maxxion R, Vitrebond e Ketac Molar EasyMix, respectivamente. Diferenças estatísticas significativas entre os materiais foram verificadas antes e após a recarga (p=0,001). Após a aplicação tópica de flúor, os cimentos de ionômero de vidro apresentaram capacidade de recarga de flúor. Conclusão: Cimentos de ionômero de vidro avaliados foram capazes de liberar flúor em soluções de ciclagem de pH e podem recarregar flúor através da aplicação tópica.
Objective: To evaluated the ability to fluoride release and recharge in the different glass ionomer cements during simulation of cariogenic challenge. Material and method: Twelve samples were made for each experimental group: conventional glass ionomer cements, Maxxion R (FGM), Ketac Molar EasyMix (3M ESPE); resin modified glass ionomer cement, Vitrebond (3M ESPE); and composite resin n Filtek™Z350XT (3M ESPE), negative control. The samples were immersed alternately in pH cycling method, remaining 6 hours in demineralization solution and 18 hours in remineralization solution and maintained at 37 °C. Fluoride release was measured 1, 2, 7, and 14 days before and after recharging with specific electrode coupled to the analyzer apparatus pH/fluoride, each measurement with calibrated solutions of sodium fluoride to 1 and 10 ppm, prepared with TISAB II. For reading was added 0.5 mL of sample to an equal volume of TISAB II. Recharging was made with neutral sodium fluoride to 2% for 4 minutes in the samples, washed and again immersed pH cycling solutions. Data were subjected to two-way ANOVA and Tukey's post-hoc test (α=0.05). Result: The initial fluoride release (µgF/cm2) was 45.36 ; 37.49 and 26.35 for Maxxion R, Vitrebond and Ketac Molar EasyMix, respectively. Significant differences between the materials before and after recharging were observed (p=0.001). After topical application of fluoride, both showed ability to recharge. Conclusion: The glass ionomer cements evaluated were capable of releasing fluoride in pH cycling solutions and may recharge through of a topical application.