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This study investigated the impact of 'storage condition' and 'period of storage' on selected physico-mechanical properties and fracture reliability of a resin-based composite (RBC). Specimens, prepared from a nanofilled RBC (Filtek Z350 XT; 3M ESPE), underwent tests for degree of conversion (DC), flexural strength (σ), flexural modulus (E), and hardness. The specimens were initially grouped into dry storage at 37°C or wet storage in distilled water at 37°C. Subsequently, they were further divided into four subgroups based on the period of storage: 6, 24, 72, or 168 hours. Specimens tested immediately after preparation served as control. Data analysis employed two-way ANOVA and Weibull analysis (α = 5%). Compared to the control, an increase in DC was observed only after 72 hours of dry storage; σ showed higher values after both dry and wet storage, regardless of the storage period (except for the group wet-stored for 168 hours); E increased with dry storage for at least 24 hours or wet storage for 72 hours; and hardness increased after dry storage for at least 24 hours or wet storage for up to 72 hours. The Weibull modulus remained unchanged under any of the distinct storage conditions. Dry storage resulted in greater characteristic strength than the control, whereas wet storage contributed to higher strength values only at shorter periods (up to 24 hours). Overall, the inherent properties of RBCs with a similar composition to that tested in this study may change with varying storage conditions and periods.
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Resinas Compostas , Resistência à Flexão , Testes de Dureza , Dureza , Teste de Materiais , Resinas Compostas/química , Fatores de Tempo , Análise de Variância , Reprodutibilidade dos Testes , Valores de Referência , Propriedades de Superfície , TemperaturaRESUMO
Abstract This study investigated the impact of 'storage condition' and 'period of storage' on selected physico-mechanical properties and fracture reliability of a resin-based composite (RBC). Specimens, prepared from a nanofilled RBC (Filtek Z350 XT; 3M ESPE), underwent tests for degree of conversion (DC), flexural strength (σ), flexural modulus (E), and hardness. The specimens were initially grouped into dry storage at 37°C or wet storage in distilled water at 37°C. Subsequently, they were further divided into four subgroups based on the period of storage: 6, 24, 72, or 168 hours. Specimens tested immediately after preparation served as control. Data analysis employed two-way ANOVA and Weibull analysis (α = 5%). Compared to the control, an increase in DC was observed only after 72 hours of dry storage; σ showed higher values after both dry and wet storage, regardless of the storage period (except for the group wet-stored for 168 hours); E increased with dry storage for at least 24 hours or wet storage for 72 hours; and hardness increased after dry storage for at least 24 hours or wet storage for up to 72 hours. The Weibull modulus remained unchanged under any of the distinct storage conditions. Dry storage resulted in greater characteristic strength than the control, whereas wet storage contributed to higher strength values only at shorter periods (up to 24 hours). Overall, the inherent properties of RBCs with a similar composition to that tested in this study may change with varying storage conditions and periods.
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The sealing and bonding characteristics of luting cements may be affected by the application of desensitizers containing ingredients that induce chemical interaction with dentin organic matrix. This study evaluated the effect of different desensitizers on the immediate and long-term shear bond strength (SBS) of a self-adhesive resin cement (SARC) to dentin. Healthy bovine dentin specimens were used for the study. Gluma® Desensitizer, Desensibilize Nano P®, and Soothe® desensitizer were used in study groups, while the control group did not receive any treatment. Next, SARC (RelyXTM U200) in cylindrical mold was applied to the sample surface. All specimens were stored at 37 °C for 24 h or six months and tested for SBS. Additionally, water contact angle was measured using an optical tensiometer. Results were analyzed by analysis of variance and Student-t tests (p Ë 0.05). Application of the different types of desensitizers had no significant influence on immediate or long-term SBS of SARC to dentin (p > 0.05). Differences for water contact angle were not statistically significant among the tested groups (p = 0.450). Within the limitations of the present study, it can be concluded that the application of the different types of desensitizers had no significant influence on the SBS of a SARC to dentin.
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This in vitro study evaluated the effects of preheating, ultrasound application, and composite resin luting agent composition on the optical characteristics of feldspar ceramic laminates. The hypothesis was that the optical properties of the ceramic-luting agent-substrate unit would be affected by the composition of the luting material and use of ultrasound. Preheated restorative composite resins Charisma, IPS Empress Direct, and Filtek Z350 were used, with unheated RelyX Veneer resin cement serving as the control. The response variables for the physical properties of the materials were degree of conversion (n = 3 per material) and viscosity (n = 3 per material). Seven groups were generated based on the tested luting agent and the use of ultrasound. Color parameters were evaluated with a spectrophotometer at 3 timepoints (before luting [baseline], 24 hours after luting, and 1 month after luting), and color change was calculated according to the Commission Internationale de l'Eclairage (CIE) CIEDE 2000 formula and translucency parameters. The statistical significance of color change and viscosity was measured using 2-way analysis of variance (ANOVA), while the degree of conversion was measured using 1-way ANOVA. For translucency parameters, ANOVA on ranks and post hoc Duncan multiple range tests were performed. The control group showed the highest degree of conversion, while Filtek Z350 showed the highest viscosity. Statistically significant differences in color change between luting material groups were found under most conditions (P < 0.001), but there was no difference in translucency parameters between the luting materials (P = 0.446). Overall, the use of preheated composite resins as luting agents offers similar to poorer performance than conventional resin cement.
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Resinas Compostas , Cimentos de Resina , Cerâmica/química , Cor , Resinas Compostas/química , Resinas Compostas/uso terapêutico , Cimentos Dentários/química , Porcelana Dentária/química , Humanos , Teste de Materiais , Cimentos de Resina/química , Cimentos de Resina/uso terapêutico , Propriedades de SuperfícieRESUMO
INTRODUCTION: The success of bone-implant prostheses depends on several factors, among them an adequate distribution and passive adaptation of occlusal loading. OBJECTIVE: this study evaluated the stress distribution in mandibular implant-supported prosthesis with internal connection morse taper interface, under effect of number of implants (4 or 5) and loadings (bilateral 100 N, bilateral 300 N). MATERIALS AND METHODS: the virtual models were subjected to analysis by 3D finite element method, across four experimental conditions. RESULTS: The stress values were evenly distributed to the peri-implant bone and implants in all simulated conditions. Stress values did not increase in the same proportion as the increase in the applied load (from 100 to 300 N). The stress value was 1.1 times higher on the implants and nearly doubled (1.5-2 times) on the peri-implant bone. CONCLUSION: For mandibular implant-supported prosthesis, the morse taper interface is strongly recommended, with similar mechanical demand for four and five implants in both loading conditions. Five implants offered no additional benefit over four implants. The commercial pure titanium frameworks presented stress values close to the yield strength of the metal, especially at the intersection with the cantilever.
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Implantes Dentários , Mandíbula , Fenômenos Biomecânicos , Planejamento de Prótese Dentária , Análise do Estresse Dentário , Análise de Elementos Finitos , Próteses e Implantes , Estresse MecânicoRESUMO
OBJECTIVES: This systematic review investigated the hypothesis that preheated resin composites (RCs) used as luting agents improve the mechanical properties, physicochemical performance, and color of indirect ceramic restorations. MATERIALS AND METHODS: Literature search was performed in three databases (Medline/PubMed, Scopus, and Web of Science) and in the grey literature (OpenGrey, ProQuest, and Catalog of Theses & Dissertations from CAPES). Eligibility criteria included only studies comparing at least one preheated RC used as a luting agent with resin cements. RESULTS: Data regarding the mechanical properties, physicochemical characteristics, and color were analyzed qualitatively, and the microtensile bond strength and film thickness were also evaluated by meta-analysis. The search strategy identified 3894 papers, and 28 were full-text screened. Seven studies were included in the review, and 5 were included in the meta-analysis. No significant difference was found for microtensile bond strength (P = 0.14). Preheated RCs showed significantly higher film thickness than resin cements (P = 0.001). CONCLUSION: Overall, the use of preheated RCs as luting agents offers similar to poorer performance than using resin cements for bonding indirect restorations. CLINICAL RELEVANCE: Despite the claim that preheated RC could be used as a luting agent, further studies should investigate the effect of clinically unacceptable film thickness.
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Colagem Dentária , Cimentos Dentários , Resinas Compostas/química , Cimentos Dentários/química , Teste de Materiais , Cimentos de Resina/química , Propriedades de SuperfícieRESUMO
STATEMENT OF PROBLEM: Although the clinical use of self-adhesive flowable composite resins is convenient, the decision to use flowable or conventional composite resin remains controversial. PURPOSE: The purpose of this systematic review and meta-analysis was to assess the in vitro bond strength of self-adhesive flowable composite resins to enamel or dentin compared with conventional composite resins using etch-and-rinse or self-etch adhesive systems. MATERIAL AND METHODS: Two independent reviewers performed searches in the PubMed (MEDLINE), Cochrane Wiley, Web of Science, Scopus, and Google Scholar databases for studies reporting on the bond strength of self-adhesive flowable and conventional composite resins to enamel and dentin published from January 2010 up to September 2020. A meta-analysis software program was used for the meta-analysis. Comparisons were conducted using standardized mean differences considering the random-effects model (α=.05). RESULTS: Twenty-two studies were considered for the meta-analysis. Immediate and long-term bond strength to enamel was improved when a conventional composite resin was used in combination with an adhesive system (P<.001). Bond strength to dentin was improved by using an adhesive system in combination with a conventional composite resin (P<.001). CONCLUSIONS: The bond strength of self-adhesive flowable composite resins is lower than that of conventional composite resins, indicating limited ability to bond to enamel and dentin.
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Colagem Dentária , Cimentos de Resina , Cimentos de Resina/química , Dentina/química , Cimentos Dentários , Teste de Materiais , Propriedades de Superfície , Resinas Compostas/uso terapêutico , Resinas Compostas/química , Adesivos Dentinários/químicaRESUMO
OBJECTIVE: The purpose of this systematic review and meta-analysis was to analyze the literature on the bond strength of self-etching (SE) adhesives containing 10-MDP or other acidic functional monomers, comparing the bonding performance of both compositions. METHODS: This study is registered in PROSPERO (CRD42020175715) and it followed the PRISMA Statement. The literature search was performed in PubMed, Web of Science, SciELO, Scopus, LILACS, IBECS, and BBO from the starting coverage date through 30 June 2021. Study eligibility criteria consisted of in vitro studies that evaluated the bond strength (microtensile, microshear, tensile or shear testing) to sound dentin/enamel of a minimum of two distinct SE systems, with at least one material containing 10-MDP and one other being comprised of a distinct acidic composition. Statistical analyses were carried out with RevMan 5.3.5 and using random-effects models with the significance level at p < 0.05. Also, Bayesian network meta-analysis (NMA) was conducted using MetaInsight V3 tool. RESULTS: From 740 relevant studies evaluated in full-text analysis, 210 were incorporated to the systematic review and 206 in meta-analysis. The majority of studies was classified as having medium risk of bias (56.7%), followed by low (35.2%) and high (8.1%) risk of bias. Data from a total of 64 adhesive systems were collected, which favored the 10-MDP-based group at both dentin (overall effect: 6.98; 95% CI: 5.61, 8.36; p < 0.00001) and enamel (overall effect: 2.79; 95% CI: 1.62, 3.96; p < 0.00001) substrates. Microtensile testing was more frequently used (73.4%) in the included studies. Adhesives based on 10-MDP showed greater bonding performance than adhesives comprised of monomers such as PENTA, 6-MHP, 4-META, 4-MET, pyrophosphate esters, mixed composition or monomers derived from sulfonic acid (p ≤ 0.01); whereas similar bond strength values were verified between 10-MDP-based materials and those containing PEM-F, acrylamide phosphates, 4-AET, MAC-10, or monomers derived from polyacrylic and phosphonic acids (p ≥ 0.05). Adhesives based on GPDM were the only ones that resulted in greater bonding potential than the 10-MDP-based group (p = 0.03). Dental bonds in dentin were favored with the application of 2-step 10-MDP-based adhesives; whereas in enamel the dental bonds were favored for both 2-steps versions of adhesives, regardless of the presence of 10-MDP. Indirect evidence from NMA revealed that 1-step 10-MDP-free and universal 10-MDP-free adhesives seemed to perform worst in dentin and enamel, respectively. SIGNIFICANCE: Adhesives containing 10-MDP showed higher bonding performance than materials formulated with other acidic ingredients, although this result relied on the type of mechanical testing, type of the substrate, acidic composition of the adhesive, and the application category of the SE system. This review summarized the effects of the foregoing factors on the adhesion to dental substrates.
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Colagem Dentária , Adesivos Dentinários , Teorema de Bayes , Cimentos Dentários , Dentina , Teste de Materiais , Metacrilatos , Cimentos de Resina , Resistência à TraçãoRESUMO
PURPOSE: To evaluate the effects of pretreatment with different crosslinking agents on glass-fiber-post adhesive luting. MATERIALS AND METHODS: Single-rooted human teeth (n = 20) were randomly assigned to four groups: proanthocyanidins (PA) from grape-seed extract, cardol and cardanol (separated from cashew nut-shell liquid) and negative control (hydroethanolic solution). The solutions were applied on 37% phosphoric acid-etched dentin for 60 s. Glass-fiber posts were cemented using a three-step etch-and-rinse adhesive (Scotchbond Multi-Purpose, 3M Oral Care) and composite cement (RelyX ARC, 3M Oral Care). Slices for the push-out bond strength test were cut and tested after 24-h or 6-month storage in distilled water. The dentin underlying the adhesive layer was analyzed by micro-Raman spectroscopy to evaluate vibrational formation of collagen crosslinks. Three additional slices per group were also made and the adhesive in-situ degree of conversion (DC) was analyzed by micro-Raman spectroscopy. The results were analyzed using two-way ANOVA and Tukey's test (p < 0.05). RESULTS: No statistically significant changes in bond strength were found over time for any of the groups, except with cardol, which increased bond strength (8.4 ± 3.9 MPa at 24 h to 15.0 ± 2.9 MPa after 6 months, p < 0.001) after aging. The formation of peaks at 1117 cm-1 and 1235 cm-1 showed the presence of collagen crosslinks for all three biomodification agents. The DC outcomes showed no statistically significant differences between groups (p = 0.514). CONCLUSION: Biomodification agents did not impair adhesive polymerization. Cardol demonstrated a positive influence on intraradicular dentin bonding for glass-fiber post luting.
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Técnica para Retentor Intrarradicular , Cimentos Dentários , Materiais Dentários , Dentina , Humanos , Raiz DentáriaRESUMO
Background: To assess the efficacy of PBMT on reducing postoperative pain scores in patients submitted to thirdmolar extractions.Material and Methods: A randomized controlled trial (ReBEC:RBR-94BCKZ) was designed according to theSPIRIT and followed the CONSORT. Patients were randomly allocated according to control or PBMT groups.PBMT consisted of the application of GaAlAs laser (808nm;50mW) applied in six points (1.23 min;11 J/cm2) afterextraction. Pain scores were assessed using the Visual Analogue Scale (VAS) in millimeters evaluated after 6(T6), 24 (T24), and 48 (T48) hours. The Wilcoxon MannWhitney test was used to check for possible associationsbetween VAS scores and treatment groups.Results: A total of 101 third molar extractions were performed in 44 patients. The mean age was 28 yearsold(SD±11.54). Comparing control and intervention, PBMT group showed a significant effect on the reductionof postoperative pain at T6(mean VAS=0.9; C.I:0.631.16) compared to control (mean VAS=2.5;C.I:2.12.88)(p<0.001). The same statistically significant effect on the reduction of postoperative pain was observed at T24(PBMT mean VAS=0.72;C.I:0.510.93; control mean VAS=2.86;C.I:2.403.31;p<0.001) and T48 (PBMT meanVAS=0.64;C.I:0.360.92; control mean VAS=2.86;C.I:2.373.34;p<0.001).Conclusions: PBMT significantly reduce the postoperative pain scores when assessed 6, 24, and 48 hours afterthird molar extractions.(AU)
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Humanos , Masculino , Feminino , Dente Serotino , Dor Pós-Operatória , Dente Serotino/cirurgia , Extração Dentária , Lasers Semicondutores , Saúde Bucal , Cirurgia Bucal , Patologia Bucal , Medicina BucalRESUMO
This study evaluated the effect of different adhesive protocols on the shear bond strength (SBS) of bulk-fill resin composite repaired with bulk-fill or conventional composite. Cylindrical bulk-fill resin composite specimens were prepared and allocated into groups according to the bonding strategy: no treatment, Silane+Scotch Bond Multipurpose (S+SBMP), Tetric N Bond Universal, and Single Bond Universal. Following bonding strategy, bulk-fill or conventional composite buildups were performed. After 24 h of storage in distilled water at 37°C, shear force was applied to the interface using a universal testing machine. The data were analyzed by two-way ANOVA and Tukey test (α=0.05). SBS was influenced by the bonding strategy and the composite used (p<0.001). Irrespective of the composite used, the group S+SBMP yielded the highest SBS values (p<0.001). Repair bond strength of bulk-fill composites can be improved by using a silane coupling agent followed by a hydrophobic resin.
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Colagem Dentária , Cimentos Dentários , Resinas Compostas , Teste de Materiais , Fenômenos Mecânicos , Cimentos de Resina , Resistência ao Cisalhamento , Silanos , Propriedades de SuperfícieRESUMO
STATEMENT OF PROBLEM: The inorganic filler of resin-based luting agents and the use of an adhesive layer could influence the bonding ability, mechanical performance, and interface morphology of bonded feldspathic ceramic. PURPOSE: The purpose of this in vitro study was to investigate the influence of resin-based luting agents loaded with different inorganic filler content, with or without an adhesive, on microtensile bond strength, biaxial flexural strength, and the adhesive interface morphology of bonded ceramic specimens. MATERIAL AND METHODS: Experimental resin-based luting agents with low (55wt%), intermediate (65wt%), and high (75wt%) filler contents were bonded to ceramic specimens, with or without a layer of adhesive. The resin-based luting agents were characterized by measuring viscosity, elastic modulus, Poisson ratio, and degree of conversion (n=3 for each test). The response variables for the bonded ceramic specimens were ceramic-resin microtensile bond strength (n=30), biaxial flexural strength (n=30) and characteristic strength, and Weibull modulus. Scanning electron microscopy was used for fractographic and interface analyses of the specimens fractured in the microtensile test (n=3). Data were subjected to ANOVA with the post hoc Tukey test (α=.05). Weibull moduli were also calculated. RESULTS: Increased inorganic filler content yielded significantly higher viscosity, stiffness, and film thickness. However, the Poisson ratio and degree of conversion were not affected. The lowest bond strength values were observed for the resin-based luting agents with high inorganic filler content when no adhesive was used and for the resin-based luting agent with low filler content when the adhesive was used. The increase in filler content of the resin-based luting agent appeared to be associated with a higher frequency of mixed failures. Increased filler content resulted in higher biaxial flexural and characteristic strength and decreased structural reliability. The adhesive helped fill irregularities on ceramic and slightly increased film thickness but had only a minor effect on mechanical strength. CONCLUSIONS: Experimental resin-based luting agent loaded with high inorganic filler content strengthened the bonded feldspathic ceramic and yielded significantly higher viscosity and film thickness. In contrast, the bond strength was lower if no adhesive was used.
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Colagem Dentária , Cimentos Dentários , Cerâmica , Porcelana Dentária , Teste de Materiais , Reprodutibilidade dos Testes , Cimentos de Resina , Propriedades de Superfície , Resistência à TraçãoRESUMO
This study evaluated the immediate and 6-month dentin bond strength of universal adhesives used in etch-and-rinse or self-etch bonding strategies. The adhesives tested were Ambar Universal, G-Bond, Single Bond Universal, Tetric N-Bond Universal, and Ybond Universal. Gold standard adhesives (Scotchbond Multipurpose Plus and Clearfil SE Bond) were controls. Microtensile dentin bond strength (n=5 teeth), pH, and C=C conversion (n=3) were evaluated. Data were analyzed at α=0.05. All adhesives showed differences in pH. Ybond had intermediately strong aggressiveness, whereas the others were ultra-mild. The C=C conversion was different in most adhesives. In the etch-and-rinse strategy, all adhesives showed similar results generally except for G-Bond, which had lower bond strength than most adhesives. G-Bond and Tetric-N-Bond showed lower bond strengths after 6 months compared with 24 h, whereas the other adhesives had stable dentin bonds. In the self-etch strategy, G-Bond had lower bond strength than most adhesives. After 6 months, Ambar was the only adhesive showing lower dentin bond strength compared with 24 h. Most adhesives had discreet drops in bond strength during aging when used in the self-etch strategy. The failure modes were also material dependent, with a general pattern of increased adhesive and/or pre-testing failures after storage. In conclusion, the bonding performance of universal adhesives to dentin is material dependent. Most adhesives had stable dentin bonds with results comparable to the gold standard materials, particularly when applied in the self-etch mode. In general, it seems the use of universal adhesives in dentin should not be preceded by phosphoric acid etching.
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Colagem Dentária , Adesivos Dentinários , Adesivos , Cimentos Dentários , Dentina , Teste de Materiais , Cimentos de Resina , Resistência à TraçãoRESUMO
Tooth bleaching is considered a non-invasive treatment, although the use of highly-concentrated products may provoke increased surface roughness and enamel demineralization, as well as postoperative sensitivity. Thus, the aim of this study was to investigate whether hydrogen peroxide (H2O2) concentration would affect tooth bleaching effectiveness and the enamel surface properties. Enamel/dentin bovine specimens (6â¯×â¯4â¯mm) were immersed in coffee solution for 7â¯days and evaluated with a spectrophotometer (Easyshade; baseline), using the CIEL*a*b* color parameters. Hardness was measured using a hardness tester. The specimens were randomly assigned into four groups: one negative control, in which the specimens were not bleached, but they were irradiated with a laser-light source (Whitening Lase II, DMC Equipments); and three groups using distinct H2O2 concentration, namely LP15% (15% Lase Peroxide Lite), LP25% (25% Lase Peroxide Sensy), and LP35% (35% Lase Peroxide Sensy), all products from DMC. The bleached specimens were also irradiated with the laser-light source. After bleaching, all specimens were evaluated using scanning electron microscopy (SEM). pH kinetics and rate was monitored during bleaching. The data were analyzed using ANOVA and Tukey's test (pâ¯<â¯0.05). All bleaching gels produced similar color change (pâ¯>â¯0.05). Concerning hardness, only the LP25% and LP35% significantly reduced hardness after bleaching; also, there was a progressive tendency for a greater percentage reduction in hardness with increased H2O2 concentration of the gel (R2â¯=â¯0.9973, pâ¯<â¯0.001). SEM showed that LP25% and LP35% produced an etching pattern on enamel with prism rods exposure. In conclusion, H2O2 concentration above the 15% level does not increase bleaching effectiveness, and may increase the possibility for alteration of enamel hardness, surface morphology, and acidity of the medium. When using H2O2-based bleaching agents, dental practitioners should choose for less concentrated gels, e.g., around the 15% level.
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Esmalte Dentário/efeitos dos fármacos , Peróxido de Hidrogênio/química , Clareadores Dentários/química , Clareamento Dental/métodos , Animais , Bovinos , Cor , Testes de Dureza , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Propriedades de SuperfícieRESUMO
Ameloblastoma is an uncommon, locally aggressive benign odontogenic tumor and can reach considerable dimensions causing facial deformity and functional impairment. They are characterized by local aggressiveness. It is recommended that maxillary ameloblastomas be treated aggressively due to proximity of various vital structures. Conservative treatments such as marsupialization, enucleation and curettage while preserving bone integrity seem to be associated with a high rate of recurrence. Treatment evaluation of ameloblastomas is a complex issue, as ideally it should not be so destructive due to the benign nature of this lesion, but should be extensive enough to avoid recurrences. The present study is about a clinical case of a 16-year- old man with a unicystic ameloblastoma treated successfully with marsupialization. Patient was followed up every 12 months. About 13 years after diagnosis, the patient is clinically healthy and radiographically it is possible to observe evidence of bone repair. Key words:Odontogenic tumors, ameloblastoma, marsupialization, unicystic.
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OBJECTIVES: This study investigated whether increasing the concentration of acidic monomers in one-step adhesives would allow reducing their application time without interfering with the bonding ability to primary enamel and dentin. MATERIAL AND METHODS: Experimental one-step self-etch adhesives were formulated with 5 wt% (AD5), 20 wt% (AD20), or 35 wt% (AD35) acidic monomer. The adhesives were applied using rubbing motion for 5, 10, or 20 s. Bond strengths to primary enamel and dentin were tested under shear stress. A commercial etch-and-rinse adhesive (Single Bond 2; 3M ESPE) served as reference. Scanning electron microscopy was used to observe the morphology of bonded interfaces. Data were analysed at p<0.05. RESULTS: In enamel, AD35 had higher bond strength when rubbed for at least 10 s, while application for 5 s generated lower bond strength. In dentin, increased acidic monomer improved bonding only for 20 s rubbing time. The etch-and-rinse adhesive yielded higher bond strength to enamel and similar bonding to dentin as compared with the self-etch adhesives. The adhesive layer was thicker and more irregular for the etch-and-rinse material, with no appreciable differences among the self-etch systems. CONCLUSION: Overall, increasing the acidic monomer concentration only led to an increase in bond strength to enamel when the rubbing time was at least 10 s. In dentin, despite the increase in bond strength with longer rubbing times, the results favoured the experimental adhesives compared to the conventional adhesive. Reduced rubbing time of self-etch adhesives should be avoided in the clinical setup.
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Bis-Fenol A-Glicidil Metacrilato/química , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Adesivos Dentinários/química , Dentina/efeitos dos fármacos , Metacrilatos/química , Análise de Variância , Falha de Restauração Dentária , Glicerol/química , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Resistência ao Cisalhamento , Solventes/química , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo , Água/químicaRESUMO
Abstract Objectives: This study investigated whether increasing the concentration of acidic monomers in one-step adhesives would allow reducing their application time without interfering with the bonding ability to primary enamel and dentin. Material and methods: Experimental one-step self-etch adhesives were formulated with 5 wt% (AD5), 20 wt% (AD20), or 35 wt% (AD35) acidic monomer. The adhesives were applied using rubbing motion for 5, 10, or 20 s. Bond strengths to primary enamel and dentin were tested under shear stress. A commercial etch-and-rinse adhesive (Single Bond 2; 3M ESPE) served as reference. Scanning electron microscopy was used to observe the morphology of bonded interfaces. Data were analysed at p<0.05. Results: In enamel, AD35 had higher bond strength when rubbed for at least 10 s, while application for 5 s generated lower bond strength. In dentin, increased acidic monomer improved bonding only for 20 s rubbing time. The etch-and-rinse adhesive yielded higher bond strength to enamel and similar bonding to dentin as compared with the self-etch adhesives. The adhesive layer was thicker and more irregular for the etch-and-rinse material, with no appreciable differences among the self-etch systems. Conclusion: Overall, increasing the acidic monomer concentration only led to an increase in bond strength to enamel when the rubbing time was at least 10 s. In dentin, despite the increase in bond strength with longer rubbing times, the results favoured the experimental adhesives compared to the conventional adhesive. Reduced rubbing time of self-etch adhesives should be avoided in the clinical setup.
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Humanos , Colagem Dentária/métodos , Adesivos Dentinários/química , Bis-Fenol A-Glicidil Metacrilato/química , Esmalte Dentário/efeitos dos fármacos , Dentina/efeitos dos fármacos , Metacrilatos/química , Solventes/química , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo , Teste de Materiais , Água/química , Microscopia Eletrônica de Varredura , Reprodutibilidade dos Testes , Análise de Variância , Falha de Restauração Dentária , Resistência ao Cisalhamento , Glicerol/químicaRESUMO
Prevotella intermedia é um microrganismo anaeróbio Gram negativo, considerado um dos agentes etiológicos de doenças periodontais. Tendo em vista que o biofilme subgengival é um dos seus principais habitats, qualquer quebra na homeostase do meio pode favorecer seu desenvolvimento e consequente dano aos tecidos atingidos. Diversas pesquisas vêm sendo realizadas a fim de identificar o papel deste microrganismo nas doenças periodontais. Assim, este trabalho teve por objetivo revisar a literatura para coletar informações sobre as características e efeitos de Prevotella intermedia no contexto saúde-doença periodontal. A busca foi realizada nas bases de dados PubMed e Lilacs, bem como através de uma busca aleatória. De um total de 47 artigos incluídos, alguns principais resultados puderam ser destacados: Prevotella intermedia está fortemente associada ao quadro de doenças periodontais e suas características favorecem o acometimento e intensificação de doenças diversas. Além disso, este microrganismo é capaz de produzir pigmentos e uma variedade de enzimas as quais favorecem danos aos tecidos periodontais. Existem várias características que aumentam a patogenicidade e virulência deste microrganismo, como por exemplos a sua cápsula polissacarídica, a presença de enzimas protetoras contra o oxigênio, a presença e produção de proteases, além da estimulação de fatores de crescimento no hospedeiro. Não há consenso na literatura acerca da relação de causa-efeito entre presença de Prevotella intermedia e diabetes. Contudo, este microrganismo parece estar envolvido no quadro de pacientes HIV positivo. Por fim, é importante salientar que Prevotella intermedia pode adquirir resistência a alguns tipos de antibióticos, e, por isso, o seu controle é um desafio à clínica atual...
Prevotella intermedia is a Gram negative anaerobic microorganism, considered one of the etiologic agents of periodontal diseases. Taking into account that the subgingival biofilm is its major habitat, any break of the environment homeostasis may lead to the development of the microorganism and consequent damage to the surrounding tissues. Several researches have been conducted in order to identify the role of this microorganism in the periodontal diseases. Thus, this study aimed to review the literature in an attempt to collect information about the characteristics and effects of Prevotella intermedia in the periodontal healthdisease context. The search was performed in the PubMed and Lilacs databases, as well as under a random search. From a total of 47 included articles, some major results could be drawn: Prevotella intermedia is strongly related to the occurrence of periodontal diseases, and its characteristics lead to the incidence of several diseases. Moreover, this microorganism is able to produce pigments and a variety of enzymes, which potentiate the damage of periodontal tissues. There are several characteristics that increase the pathogenicity and virulence of this microorganism, including the polyssacharidic capsule, the presence of protective enzymes against oxygen, the presence and production of proteases, as well as the stimulation of grow factors in the host. There is no consensus in the literature regarding the cause-effect relationship between the presence of Prevotella intermedia and diabetes. However, this microorganism seems to be involved in the occurrence of HIV-positive people. Lastly, it is worth to mention that Prevotella intermedia may acquire strength to some antibiotic types, and, therefore, its control is a challenge to the current clinic...
Assuntos
Doenças Periodontais , Prevotella intermedia , Virulência , Bactérias Aeróbias Gram-NegativasRESUMO
Nos últimos anos, a população de idosos na cidade do Rio de Janeiro aumentou consideravelmente. O objetivo deste trabalho foi avaliar a saúde oral de idosos no Centro do Rio de Janeiro. A amostra foi composta por 263 idosos, frequentadores do Convento Santo Antônio, e foi utilizada a ficha de avaliação da Organização Mundial de Saúde (OMS) (1997). O IPC foi avaliado, assim como o índice CPOD e o edentulismo. O questionário a respeito da renda familiar e frequência de escovação foi aplicado. Dos participantes, 45,62% apresentaram doença periodontal. O edentulismo apareceu elevado. Dos dentes remanescentes, 13,9% apresentavam cárie. A condição dos idosos examinados foi considerada precária.
Assuntos
Humanos , Idoso , Assistência Odontológica para Idosos , Estudos Epidemiológicos , Odontologia Geriátrica , Saúde Bucal , Fatores SocioeconômicosRESUMO
A obturação do canal radicular simultânea ao ato cirúrgico está indicada nos casos em que o tratamento endodôntico convencional fracassou, não havendo regressão da lesão periapical, ou quando não é possível a obturação dos canais radiculares devido à presença de exsudação persistente. O presente caso clínico visa a relatar a técnica de obturação do canal radicular simultânea ao ato cirúrgico, bem como enfatizar os passos operatórios a serem seguidos para obtenção do sucesso operatório.