996 resultados para DENTIN
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The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.
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Currently, periodontal aesthetics has been prized for harmony of the smile. The clinical crown lengthening, gingival excess or altered passive eruption, is effectively corrected by periodontal surgery. The purpose of this paper is to show, through a literature review, some types of surgery on clinical crown lengthening and root coverage. Clinical crown lengthening is done to Change the size of the anterior teeth and to optimize the cosmetic result of treatment with new coronal restoration and other cosmetic dental care. In general, the treatment plan and the choice of operative technique begin with careful clinical examination. Recessions tissue can be defined as a displacement of the gingival margin toward the junction mucogingival exposing the root surface. These, when present, impacting on patient comfort by providing the occurrence of cervical dentin hypersensitivity, and the esthetic, the amendment of the gum line. Successful treatment of recessions is based on knowledge of its etiology and assessment of predictability of surgical techniques that aim to root coverage. Through literature review, we can conclude that the types of surgery most often used are: 1) to increase the clinical crown, gingivectomy, flap surgery and gingivoplasty osteotomy, and 2) for root coverage, the use will depend on the amount of gum keratinized and especially the classification of Miller.
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The purpose of this study was to use a fluorescent dye and CLSM microscope to observe the effect of different light intensities on dentin tensile bond strength. Flat dentin surfaces were created on 16 intact human third molars and divided in 4 groups: Group G1 - halogen - KM -200R®; Group G2 - LED - Ultraled®; Group G3 - LED - UltraLume LED5® and Group G4 - LED - Biolux Single V®. For all the groups, the restoration procedure used Single Bond® adhesive, mixed with rodamin B and InTen-S® composite resin. Then, they were cut on serial sections to obtain 1 mm2 area and submitted to micro tensile test and after words, the fractures were analyzed with a digital microscope and CLSM. The statistical analysis showed that all in all groups, except Group G2, which had a significant smaller tensile bond strength ratio. The fracture mode analysis showed that there were significant differences when comparing groups G1 / G2, and G2 / G4. There is no evidence of relevant differences among the other groups. With these results, we conclude that the use of fluorescent dye and CLSM demonstrated to be a simple and nondestructive technique, and that there are evidences that light intensities influenced the dentine tensile.
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ABSTRACT. Introduction: an in vitro model was used to measure the hydraulic conductance in human dentin discs treated with oxalic acid for 15, 30 or 60 s maintaining the occlusive effect and measuring 7 and 14 days after application. Methods: 45 dentin discs measuring 1 mm thick were obtained from human third molars which were free of caries and in no occlusion; the samples were obtained from patients aged 16 to 30 years. Discs were sorted out into three study groups (n = 15) depending on the time of application of a commercial solution of oxalate-based dentin desensitizer (DD) (BisBlock®) which contains ˂ 5% oxalic acid of 1.5-1.8 pH: in group A the agent was applied for 15 s, in group B it was applied for 30 s, and in group C for 60 s. The hydraulic conductance of each disc was calculated after acid etching, which corresponds to the maximum permeability of discs (100%) after immediate application of oxalic acid, as well as seven and fourteen days of storage in saline solution. The statistical analysis was done with ANOVA test and post-hoc Games-Howell test. Results: 35,46 ± 23.41% in Group A, 36.34 ± 15.88% in Group B and 24.99 ± 14.99% in Group C, showing that the use of DD for 15, 30 or 60 s decreased permeability in a statistically significant manner (p <0.05). Conclusions: DD was effective in reducing hydraulic conductance regardless of application time, but this reduction was temporary only, since after seven days permeability returns to values close to those of baseline.
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Endodontic sealer residues on dentinal surface have negative effects on adhesion of adhesives system and/or can cause discoloration of the dental crown. Objective: To evaluate the efficacy of 95% ethanol in removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal surface. Material and methods: Thirty-two bovine incisor dental crown fragments (0.5 mm x 0.5 mm) were treated with 17% EDTA and 2.5% NaOCl. The specimens were divided into three experimental groups (n = 10): G1 (AH Plus), G2 (Epiphany SE) and G3 (Sealapex). In each group was applied a coating of one endodontic sealer type and were left undisturbed for 5 minutes. After this period, the specimens were cleaned with 95% ethanol. The control group was composed by two specimens that did not receive any sealer or cleaning treatment. The sealer residues persistence after cleaning with 95% ethanol was evaluated by scanning electron microscopy (x500) and a score system was applied. Data obtained were analyzed by Kruskal-Wallis and Dunn tests (α = 5%). Results: Moderate amount of endodontic sealer residues were observed in all groups, regardless of the endodontic sealer compositions. G1, G2 and G3 presented similar amount of sealer residues on dentinal surface after cleaning with 95% ethanol (p > 0.05). Conclusion: 95% ethanol was inefficiency to remove completely AH Plus, Epiphany SE and Sealapex residues of sealer-contaminated dentin.
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This study aimed to evaluate the effect of Er:YAG (L) and diamond drills (DD) on: 1) the microshear bond strength (MPa); 2) the adhesive interface of two-step (TS) – Adper Scotchbond Multipurpose and one-step (OS) adhesives – Adper EasyOne, both from 3M ESPE. Material and methods: According to the preparation condition and adhesives, the samples were divided into four groups: DD_TS (control); DD_OS; L_TS and L_OS. 60 bovine incisors were randomly divided into experimental and groups: 40 for microshear bond strength (n = 10) and 20 for the adhesive interface morphology [6 to measure the thickness of the hybrid layer (HL) and length of tags (t) by CLSM (n = 3); 12 to the adhesive interface morphology by SEM (n = 3) and 2 to illustrate the effect of the instruments on dentine by SEM (n = 1)]. To conduct the microshear bond strength test, four cylinders (0.7 mm in diameter and 1 mm in height with area of adhesion of 0.38 mm) were constructed with resin composite (Filtek Z350 XT – 3M ESPE) on each dentin surface treated by either L or DD and after adhesives application. Microshear bond strength was performed in universal testing machine (EMIC 2000) with load cell of 500 kgf and a crosshead speed of 0.5 mm / min. Adhesive interface was characterized by thickness of hybrid layer (HL) and length of tags (t) in nm, with the aid of UTHSCSA ImageTool software. Results: Microshear bond strength values were: L_TS 34.10 ± 19.07, DD_TS 24.26 ± 9.35, L_OS 33.18 ± 12.46, DD_OS 21.24 ± 13.96. Two-way ANOVA resulted in statistically significant differences only for instruments (p = 0.047). Mann-Whitney identified the instruments which determined significant differences for HL thickness and tag length (t). Concerning to the adhesive types, these differences were only observed for (t). Conclusion: It can be concluded that 1) laser Er:YAG results in higher microshear bond strength values regardless of the adhesive system (TS and OS); 2) the tags did not significant affect the microshear bond strength; 3) the adhesive interface was affected by both the instruments for cavity preparation and the type of adhesive system used.
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Introduction: Endodontic sealer residues on dentinal surface have negative effects on adhesion of adhesives system and/or can cause discoloration of the dental crown. Objective: To evaluate the efficacy of 95% ethanol in removal of residues of epoxy-based (AH Plus), methacrylate-based (Epiphany SE) or calcium-based (Sealapex) sealers on dentinal surface. Material and methods: Thirty-two bovine incisor dental crown fragments (0.5 mm x 0.5 mm) were treated with 17% EDTA and 2.5% NaOCl. The specimens were divided into three experimental groups (n = 10): G1 (AH Plus), G2 (Epiphany SE) and G3 (Sealapex). In each group was applied a coating of one endodontic sealer type and were left undisturbed for 5 minutes. After this period, the specimens were cleaned with 95% ethanol. The control group was composed by two specimens that did not receive any sealer or cleaning treatment. The sealer residues persistence after cleaning with 95% ethanol was evaluated by scanning electron microscopy (x500) and a score system was applied. Data obtained were analyzed by Kruskal-Wallis and Dunn tests (α = 5%). Results: Moderate amount of endodontic sealer residues were observed in all groups, regardless of the endodontic sealer compositions. G1, G2 and G3 presented similar amount of sealer residues on dentinal surface after cleaning with 95% ethanol (p > 0.05). Conclusion: 95% ethanol was inefficiency to remove completely AH Plus, Epiphany SE and Sealapex residues of sealercontaminated dentin.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Aim: This study investigated the flowability, setting time, pH, calcium release and bond strength of a MTA-based cement (MTA Fillapex®) compared to AH Plus and Sealapex. Materials and methods: For the flowability test, the ISO 6876:2001 specification was utilized and for the setting time test, the ASTM C266-03 specification was utilized. For the pH and calcium release measurements, 10 samples were prepared for each group and analyzed for several different periods. For the push-out test, dentin disks were distributed into three groups, according to the cement utilized and into three subgroups, according to the root third (n = 10). After obturation, the specimens underwent push-out testing. The data were compared statistically using a significance level of 5%. Results: The flowability of all materials was found to be similar (p > 0.05). The setting times were different among the groups tested (MTA Fillapex < Sealapex < AH Plus) (p < 0.05). At days 7 and 28, the MTA Fillapex presented the higher pH values (p < 0.05). At 24 hours and at 14 days, the calcium release of the MTA Fillapex was similar to that of Sealapex (p > 0.05). AH Plus presented the lowest pH and calcium release values (p < 0.05). In all root thirds, the adhesion to the dentin of the MTA Fillapex and Sealapex were significantly lower than that of AH Plus (p < 0.05). Conclusion: MTA Fillapex and Sealapex presented several similar properties and both were found to be different than AH Plus. Clinical significance: This study evaluated the physicochemical and mechanical properties of new MTA-based root canal cement, in order to use this scaler in root canal fillings. MTA Fillapex showed satisfactory properties for clinical use.
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The laser has been widely used in many specialties of dentistry and several wavelengths have been investigated as a substitute for high-speed handpiece. The purpose of this paper is to review the literature about the use of Er:YAG and Er,Cr:YSGG lasers in cavity preparation for dental tissues. Despite the differences in wavelength, pulse duration and energy, the morphological characteristics of the irradiated dentin surface with these lasers are comparable, as well as its effects as methods of dental caries prevention. Thus, Er:YAG and Er,Cr:YSGG lasers prepared cavities with similar effects on the dental tissue, however, further investigations about ideal irradiation conditions are needed for both lasers.
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Aim: To evaluate the effectiveness of ProTaper universal retreatment system in the removal of root canal filling material with thermomechanical compaction, in comparison to manualmechanical technique, associated with orange oil or eucalyptol. Materials and methods: Forty extracted lower incisors were filled with thermomechanical compaction technique. After 3 years, the root canal filling was removed by: G1 - manualmechanical technique with orange oil; G2 - manual-mechanical technique with eucalyptol; G3 - ProTaper universal retreatment system with orange oil and G4 - ProTaper universal retreatment system with eucalyptol. In sequence, all root canals were instrumented to F5 instrument. The teeth were longitudinally grooved, images of buccal half were obtained in stereomicroscope and covered area by root canal filling material was measured using image tool software, in cervical, middle and apical radicular thirds. The results were subjected ANOVA and Tukey test (p = 0.05). Results: In all thirds, the manual-mechanical technique showed lower presence of root canal filling material on root canal dentin in comparison to ProTaper retreatment universal system, regardless of organic solvent used (p < 0.05). There is no difference between organic solvents in removal root canal filling material (p > 0.05). Conclusion: The ProTaper universal retreatment system showed lower effectiveness in removal root canal filling material than manual-mechanical technique, regardless of organic solvents (orange oil or eucalyptol oil) used. Clinical significance: Recently rotary instruments have been proposed to removal of root canal filling material. However, there are no studies evaluating its effectiveness in removal root canal filling material in association with orange oil or eucalyptol oil.
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The human dentition is naturally translucent, opalescent and fluorescent. Differences between the level of fluorescence of tooth structure and restorative materials may result in distinct metameric properties and consequently perceptible disparate esthetic behavior, which impairs the esthetic result of the restorations, frustrating both patients and staff. In this study, we evaluated the level of fluorescence of different composites (Durafill in tones A2 (Du), Charisma in tones A2 (Ch), Venus in tone A2 (Ve), Opallis enamel and dentin in tones A2 (OPD and OPE), Point 4 in tones A2 (P4), Z100 in tones A2 ( Z1), Z250 in tones A2 (Z2), Te-Econom in tones A2 (TE), Tetric Ceram in tones A2 (TC), Tetric Ceram N in tones A1, A2, A4 (TN1, TN2, TN4), Four seasons enamel and dentin in tones A2 (and 4SD 4SE), Empress Direct enamel and dentin in tones A2 (EDE and EDD) and Brilliant in tones A2 (Br)). Cylindrical specimens were prepared, coded and photographed in a standardized manner with a Canon EOS digital camera (400 ISO, 2.8 aperture and 1/ 30 speed), in a dark environment under the action of UV light (25 W). The images were analyzed with the software ScanWhite©-DMC/Darwin systems. The results showed statistical differences between the groups (p < 0.05), and between these same groups and the average fluorescence of the dentition of young (18 to 25 years) and adults (40 to 45 years) taken as control. It can be concluded that: Composites Z100, Z250 (3M ESPE) and Point 4 (Kerr) do not match with the fluorescence of human dentition and the fluorescence of the materials was found to be affected by their own tone.
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This study evaluated the effect of Er,Cr:YSGG laser irradiation on the external adaptation of composite resin restorations in caries-affected cavities. Mixed class V cavity preparations were performed in 36 intact human third molars, in half of which caries was artificially induced. Both healthy and carious dentin were etched with 35% phosphoric acid (Ultradent Products Inc., South Jordan, Utah, USA), and the teeth were divided into three groups, i.e., (a) untreated etched dentin, (b) application of the Er, Cr:YSGG laser and (c) use of chlorhexidine as an adjunct in the bonding process. Restorations were fabricated with Z350 XT FiltekTM composite resin (3M ESPE) and subsequently the specimens were subjected to thermocycling to simulate artificial ageing. Quantitative analysis of external adaptation was performed by scanning electron microscopy in both healthy and affected dentin using epoxy resin replicas. It was concluded that the application of laser and chlorhexidine did not affect the percentages of marginal adaptation of class V restorations. Furthermore, thermocycling may influence adaptation values.
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To evaluate the effect of oxalic acid in cervical hypersensitivity, used under two different resin restorations one based on methacrylate and another based on silorane. Methods: 19 patients with “LCNC with hypersensitivity” were distributed into 4 groups according to treatment: G1 (n = 31): 0.5% oxalic acid (Desenssiv, SSWhite) + Z250 (3MESPE), G2 (n = 31): 0.5% oxalic acid + Filtek Silorane - P90 (3MESPE), G3 (n = 30): Distilled water + Z250; G4 (n = 30): Distilled water + Filtek Silorane - P90. Two clinical calibrated (kappa> 0.75) evaluated the sensitivity of the teeth: Before treatment, at 30, 60 and 90 days post-treatment (VAS). Results: The 4 groups at 30, 60 and 90 days reduced HS compared with the baseline (p <0.05). G1 and G2 showed less HS than G3 and G4 (p <0.05). Conclusion: The 4 restorative procedures significantly reduce the hypersensitivity, 30, 60 and 90 days compared to the baseline.
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The aim of this study was to compare the hydraulic conductance in human dentin disks, where 1, 2 or 3 layers of adhesive Single Bond 2(SB2) and Single Bond Universal(SBU) were applied. 84 1 mm. thick(+/- 0.1 mm.) dentin disks were fabricated. Samples were divided into 7 groups (n = 12) Control (without adhesive), A1: one layer of SB2, A2: two layers SB2, A3: three layers SB2, B1: one layer SBU, B2: two layers of SBU, B3: three layers of SBU. The results as averages for the hydraulic conductance of each separate group were: Control (0.0363), A1 (0.0206), A2 (0.0070), A3 (0.0061), B1 (0.0161), B2 (0.0062), B3(0.0056) expressed µl/min.cm2. There is statistically significant difference CH, between the control group and those samples that one coat was applied (p = 0.000) and also between the application of one and two layers (p = 0.000). No difference between the two adhesives (p = 0.434). Summary Key words: Dentin, conductance, difussion adhesive layers.