Juliê Marra

Universidade Paulista, San Paulo, São Paulo, Brazil

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Publications (25)21.59 Total impact

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    ABSTRACT: OBJECTIVE: To evaluate the antimicrobial activity and surface properties of an acrylic resin containing the biocide polymer poly (2-tert-butylaminoethyl) methacrylate (PTBAEMA). BACKGROUND: Several approaches have been proposed to prevent oral infections, including the incorporation of antimicrobial agents to acrylic resins. MATERIALS AND METHODS: Specimens of an acrylic resin (Lucitone 550) were divided into two groups: 0% (control) and 10% PTBAEMA. Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Surface topography was characterised by atomic force microscopy and wettability properties determined by contact angle measurements. RESULTS: Data of viable cells (log (CFU + 1)/ml) for S. aureus (control: 7.9 ± 0.8; 10%: 3.8 ± 3.3) and S. mutans (control: 7.5 ± 0.7; 10%: 5.1 ± 2.7) showed a significant decrease with 10% of PTBAEMA (Mann-Whitney, p < 0.05). For C. albicans (control: 6.6 ± 0.2; 10%: 6.6 ± 0.4), there was no significant difference between control and 10% of PTBAEMA (Kruskal-Wallis, p > 0.05). Incorporating 10% PTBAEMA increased surface roughness and decreased contact angles. CONCLUSION: Incorporating 10% PTBAEMA into acrylic resins increases wettability and roughness of acrylic resin surface; and decreases the adhesion of S. mutans and S. aureus on acrylic surface, but did not exhibit antimicrobial effect against C. albicans.
    Gerodontology 12/2012; · 1.83 Impact Factor
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    ABSTRACT: OBJECTIVES: The purpose of this study was to evaluate the antimicrobial activity of an acrylic resin combined with an antimicrobial polymer poly (2-tert-butylaminoethyl) methacrylate (PTBAEMA) to inhibit Staphylococcus aureus, Streptococcus mutans and Candida albicans biofilm formation. MATERIAL AND METHODS: Discs of a heat-polymerized acrylic resin were produced and divided according to PTBAEMA concentration: 0 (control), 10 and 25%. The specimens were inoculated (10(7) CFU/mL) and incubated at 37ºC for 48 h. After incubation, the wells were washed and each specimen was sonicated for 20 min. Replicate aliquots of resultant suspensions were plated at dilutions at 37ºC for 48 h. The number of colony-forming units (CFU) was counted and expressed as log (CFU+1)/mL and analyzed statistically with α=.05. RESULTS: The results showed that 25% PTBAEMA completely inhibited S. aureus and S. mutans biofilm formation. A significant reduction of log (CFU+1)/mL in count of S. aureus (control: 7.9±0.8A; 10%: 3.8±3.3B) and S. mutans (control: 7.5±0.7A; 10%: 5.1±2.7B) was observed for the group containing 10% PTBAEMA (Mann-Whitney, p<0.05). For C. albicans, differences were not significant among the groups (control: 6.6±0.2A; 10%: 6.6±0.4A; 25%: 6.4±0.1A), (Kruskal-Wallis, p>0.05, P=0.079). CONCLUSIONS: Acrylic resin combined with 10 and 25% of PTBAEMA showed significant antimicrobial activity against S. aureus and S. mutans biofilm, but it was inactive against the C. albicans biofilm.
    Journal of applied oral science: revista FOB 12/2012; 20(6):643-648. · 0.39 Impact Factor
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    ABSTRACT: Objective: OBJETIVE: The incorporation of 2-tert-butylaminoethyl methacrylate (TBAEMA) into acrylic resins may be a possible alternative to reduce the biofilm formation on denture surface, since it has been reported that the presence of amine groups in TBAEMA composition could indicate antimicrobial activity. The objective of this study was to investigate the chemical interaction between TBAEMA and an acrylic resin (Onda-Cryl) and the presence of amine groups on the resin surface, and assess the glass transition temperature (Tg) and flexural strength of the resin after the incorporation of TBAEMA. Method: METHOD: Specimens were divided in five groups according to the concentration of TBAEMA incorporated to acrylic resin: 0%, 1%, 2%, 3% and 4%. Specimens’ surfaces were evaluated by Electron Spectroscopy for Chemical Analysis (ESCA) to detect the presence of amine groups, represented by nitrogen ratios. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) analysis were used to evaluate the polymerization process of acrylic resin in the presence of TBAEMA and the influence of the incorporation of TBAEMA on Tg, respectively. Flexural strength data were analyzed by ANOVA/Tukey’s test (α<0.05). Result: RESULT: Different nitrogen ratios were observed on specimens’ surfaces: 0.36%, 0.54%, 0.35% and 0.20% for groups 1%, 2%, 3% and 4%, respectively. FTIR results indicated copolymerization of acrylic resin and TBAEMA, and DSC results demonstrated that the incorporation of TBAEMA reduced Tg. Significant differences were found for flexural strength (p<0.05). The means and standard deviations for flexural strength were 91.1±5.5A, 77.0±13.1B, 67.2±12.5B, 64.4±13.0B and 67.2±5.9B MPa for groups 0%, 1%, 2%, 3% and 4%, respectively. Conclusion: CONCLUSION: The incorporation of TBAEMA to the acrylic resin resulted in copolymerization and the presence of amine groups on specimens’ surfaces, and in decrease of Tg and flexural strength.
    IADR General Session 2012; 06/2012
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    ABSTRACT: The objective of this study is to compare the effects of canine guidance (CG) and bilateral balanced occlusion (BBO) on denture satisfaction and kinesiographic parameters of complete denture wearers, by means of a cross-over trial. Fifty edentulous patients received new maxillary and mandibular complete dentures. After the intra-oral adjustments and adaptation period, 44 participants were enrolled in the trial and randomly received a sequence of occlusal schemes: BBO followed by CG, or CG followed by BBO. Outcomes were assessed after 30 days of each occlusal scheme. Participants answered a denture satisfaction questionnaire and a kinesiograph instrument recorded mandibular physiologic movements and pattern of maxillary denture movement during chewing. Wilcoxon test and paired sample t-test were used to compare satisfaction levels and kinesiographic data for each occlusal scheme, respectively (α=0.05). The results showed no differences between occlusal schemes on participant's satisfaction and in any of the kinesiographic parameters studied, except for the vertical intrusion of the maxillary complete denture during chewing, which was lower with CG. It can be concluded that the occlusal scheme did not influence on satisfaction and kinesiographic parameters evaluated, as long as volume and resilience of residual edentulous ridges of the participants were normal. Clinical Trial Registration Identifier: NC.T01420536.
    Journal of Oral Rehabilitation 04/2012; 39(8):615-22. · 2.34 Impact Factor
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    ABSTRACT: Objectives: The incorporation of the polymer poly (2-tert-butylaminoethyl) methacrylate (PTBAEMA) to acrylic resins may represent a possible alternative to reduce biofilm formation on denture surface and the prevention of denture stomatitis. The ability of Candida albicans to adhere to polymeric surfaces has been correlated with hydrophobic surfaces. Thus, surface properties are important parameters related to the initial phase of biofilm formation. The purpose of this study was to evaluate the superficial hydrophobicity of disc-shaped specimens obtained from an acrylic resin (Lucitone 550) containing the biocide polymer PTBAEMA. Methods: Specimens were divided into three groups (n=10), according to the PTBAEMA concentration: 0% (control), 5% and 10%. The water contact angle measurements were performed to characterize the surface hydrophobicity of the specimens, using an automated goniometer (Ram-hart 200). Measurements in two different locations were made for each specimen. Data were analyzed by one-way ANOVA and Tukey’s test, at 5% of significance. Results: Contact angle values of specimens containing PTBAEMA were lower than those measured on control group. Significant differences (P< .05) were detected among the groups (Group 0%= 57.3°±2.2A, Group 5%= 28.7°±3.2B, Group 10%= 44.3°±3.9C). Conclusions: It was observed that PTBAEMA incorporation decreased the hydrophobicity of acrylic resin surfaces, demonstrated by the contact angle decrease. Thus, incorporating PTBAEMA into acrylic resins could be a possible alternative for the prevention of denture stomatitis.
    AADR Annual Meeting 2012; 03/2012
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    ABSTRACT: Objectives: The purpose of this study was to evaluate the impact of replacing conventional mandibular complete dentures by implant-supported fixed dentures on the kinesiographic parameters of edentulous patients. Methods: Edentulous patients (n=10) received one set of new complete dentures. After the intraoral adjustments and adaptation period, the kinesiograph instrument K6-I (Myotronics Research Inc., Seattle, WA) was used to record opening and closure movement limits, postural rest position, chewing cycle and pattern of maxillary complete denture movement during chewing. Afterwards, the patients had their mandibular denture replaced by an implant-supported fixed denture and the same evaluation protocol was performed after 30, 60, 90, 180 and 360 days. Data were analyzed using paired t test (α=.05). Results: It was observed a significant increase in the most parameters related to extension of opening and closure movement limits after the treatment with implant-supported fixed dentures, for all periods evaluated. A greater vertical intrusion of the maxillary complete denture during chewing was also perceived after 360 days (0.38 mm). A significant reduction in the movement between rest position and intercuspal position was also found for the periods 30 (0.69mm), 60 (0.79mm) and 90 days (0.56mm). No significant differences were observed for chewing cycle. Conclusions: The treatment with implant-supported fixed denture interferes on amplitude of opening and closure movement limits and on intrusion of the maxillary complete denture during chewing.
    AADR Annual Meeting 2012; 03/2012
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    ABSTRACT: The prevalence of wearing and fracture of complete dentures was evaluated among edentulous patients treated in two dental schools in Brazil. Acceptance and wearing of complete dentures are related to adaptive behaviour of edentulous patients. However, one reason that could interfere with the wearing dentures is their potential to fracture, which is still a common complication in denture rehabilitation practice. Two hundred and twenty-four edentulous patients rehabilitated with complete dentures from 2000 to 2005 in Araçatuba and Araraquara Dental School, University of State of São Paulo, were assessed in 2006 and 2007 to answer a questionnaire about wearing and fracture of their dentures. Statistical analysis were performed using Epi Info software and chi-squared test to compare maxillary and mandibular data (α = 0.05). Almost 26% of the patients did not wear their dentures, and among the remainder, the majority wore the maxillary denture. About 30% of the dentures were fractured, with higher prevalence in the maxillary arch (p = 0.003). Discontinuation of wearing dentures was quite high, especially considering the treatment which was carried out in university clinics. Prevalence of fractures was also high, greater for the maxillary denture, and was one of the main reasons for non-wearing of complete dentures.
    Gerodontology 08/2011; 29(2):e728-34. · 1.83 Impact Factor
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    ABSTRACT: Polymethyl methacrylate (PMMA) resins have commonly been used as a denture base material. However, denture bases may act as a reservoir for microorganisms and contribute to oral diseases in denture wearers. It is hypothesized that the 2-tert-butylaminoethyl methacrylate (TBAEMA) incorporated to acrylic resins should have antimicrobial activity related to the presence of amino groups on acrylic resin surface. The objectives of this study were to evaluate the presence of amino groups on acrylic resin surface and the influence on flexural strength after incorporation of TBAEMA. Six groups were divided according to the concentration of TBAEMA incorporated to acrylic resin (Lucitone 550): 0, 0.5, 1.0, 1.5, 1.75 and 2%. Specimens surface were evaluated by Electron Spectroscopy for Chemical Analysis (ESCA) to detect the presence of amino groups, represented by nitrogen ratios. Flexural strength of the specimens was tested and results were analyzed by ANOVA and Tukey's test (α=0.05). Different nitrogen ratios were observed on specimen surfaces: 0, 0.13, 0.74, 0.66, 0.92 and 0.33% for groups 0, 0.5, 1.0, 1.5, 1.75, and 2%, respectively. Significant differences were found for flexural strength (p<0.001). The mean flexural strength values were 98.3±3.9, 93.3±3.2, 83.9±2.1, 82.8±5.2, 71.2±5.1 and 17.3±3.2 MPa for groups 0, 0.5, 1.0, 1.5, 1.75, and 2%, respectively. Within the limitations of this study, the incorporation of TBAEMA results in the presence of the potentially antimicrobial amino groups on specimen surfaces, but affect the flexural strength, depending on the concentration of TBAEMA.
    Journal of applied oral science: revista FOB 06/2011; 19(3):195-9. · 0.39 Impact Factor
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    ABSTRACT: Objectives: This study aimed to compare the effects of canine guidance and bilateral balanced occlusion on satisfaction and kinesiographic parameters of edentulous patients wearing complete dentures. Methods: Sixty-nine edentulous patients received one set of new complete dentures with bilateral balanced occlusion. After intraoral adjustments and adaptation period, the patients were randomly divided in two groups: canine guidance (CG) and bilateral balanced occlusion (BBO). After 30 days, the kinesiograph instrument K6-I (Myotronics Research Inc., Seattle, WA) was used to record opening and closure movement limits, postural rest position, chewing cycle and pattern of maxillary complete denture movement during chewing a test food (a piece of sandwich loaf) for 20 seconds. They also answered a denture satisfaction questionnaire. Immediately after that, the patients had their occlusal scheme changed and a new evaluation was performed 30 days after. Kinesiographic data were analyzed using t test (a=.05) and the denture satisfaction questionnaire using Wilcoxon test (a=.05). Results: The results showed no differences (P>.05) between the occlusal schemes in any of the kinesiographic parameters studied. Moreover, no differences (P>.05) were found for any answer from the denture satisfaction questionnaire. Conclusions: It can be concluded that mandibular physiologic movements, maxillary complete denture movement during chewing and patient satisfaction were not influenced by the occlusal scheme used in conventional complete dentures.
    IADR General Session 2011; 03/2011
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    ABSTRACT: Objectives: The objective of this study was to evaluate the impact of replacing conventional mandibular complete dentures by implant-supported fixed dentures on the oral health-related quality of life and kinesiographic parameters of edentulous patients. Methods: Edentulous patients (n=15) received one set of new complete dentures. After the intraoral adjustments and adaptation period, the kinesiograph instrument K6-I (Myotronics Research Inc., Seattle, WA) was used to record opening and closure movement limits, postural rest position, chewing cycle and pattern of maxillary complete denture movement during chewing. Additionally, the Brazilian version of Oral Health Impact Profile for assessing edentulous subjects (OHIP-EDENT) was used. Afterwards, the patients had their mandibular denture replaced by an implant-supported fixed denture and the same evaluation protocol was performed after 30 days. Kinesiographic data were analyzed using t test (a=.05) and OHIP-EDENT using Wilcoxon test (a=.05). Results: After 30 days of the insertion of the implant-supported fixed denture was observed a significant increase in vertical extension of chewing cycle (10.57 mm to 13.17mm) and maximum opening (26.79 mm to 31.38 mm). A significant reduction in anteroposterior movement between rest position and intercuspal position was also found (2.21 mm to 1.65 mm). No significant differences were observed for maxillary complete denture movement during chewing. The OHIP-EDENT showed that there was a significant improvement on functional limitation and social disability. However, no difference to general oral health-related quality of life was found to subjects after insertion of the implant-supported fixed denture. Conclusions: The insertion of implant-supported fixed dentures was enough to change mandibular physiologic movements, with increases in vertical amplitude of maximal opening and masticatory cycles. Moreover, participants perceived improvements on functional limitation and social disability as a consequence of implant treatment.
    IADR General Session 2011; 03/2011
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    ABSTRACT: Polymethyl methacrylate (PMMA) resins have commonly been used as a denture base material. However, denture bases may act as a reservoir for microorganisms and contribute to oral diseases in denture wearers. It is hypothesized that the 2-tert-butylaminoethyl methacrylate (TBAEMA) incorporated to acrylic resins should have antimicrobial activity related to the presence of amino groups on acrylic resin surface. Objectives: The objectives of this study were to evaluate the presence of amino groups on acrylic resin surface and the influence on flexural strength after incorporation of TBAEMA. Methods: Six groups were divided according to the concentration of TBAEMA incorporated to acrylic resin (Lucitone 550): 0%, 0.5%, 1.0%, 1.5%, 1.75% and 2%. Specimens surface were evaluated by Electron Spectroscopy for Chemical Analysis (ESCA) to detect the presence of amino groups, represented by nitrogen ratios. Flexural strength of the specimens was tested and results were analyzed by ANOVA/Tukey's test (a=.05). Results: Different nitrogen ratios were observed on specimen surfaces: 0%, 0.13%, 0.74%, 0.66%, 0.92% and 0.33% for groups 0, 0.5, 1.0, 1.5, 1.75, and 2%, respectively. Significant differences were found for flexural strength (p<0.001). The mean flexural strength values were 98.33.9A, 93.33.2A, 83.92.1B, 82.85.2B, 71.25.1C and 17.33.2D MPa for groups 0, 0.5, 1.0, 1.5, 1.75, and 2%, respectively. Same capital letters indicate no significant difference detected by the post hoc tests. Conclusion: Within the limitations of this study, the presence of amino groups on specimen surfaces after the incorporation of TBAEMA into acrylic resin could indicate possibility of antimicrobial activity, but may affect the flexural strength, depending on the concentration of TBAEMA.
    IADR General Session 2010; 07/2010
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    ABSTRACT: The method of porosity analysis by water absorption has been carried out by the storage of the specimens in pure water, but it does not exclude the potential plasticising effect of the water generating unreal values of porosity. The present study evaluated the reliability of this method of porosity analysis in polymethylmethacrylate denture base resins by the determination of the most satisfactory solution for storage (S), where the plasticising effect was excluded. Two specimen shapes (rectangular and maxillary denture base) and two denture base resins, water bath-polymerised (Classico) and microwave-polymerised (Acron MC) were used. Saturated anhydrous calcium chloride solutions (25%, 50%, 75%) and distilled water were used for specimen storage. Sorption isotherms were used to determine S. Porosity factor (PF) and diffusion coefficient (D) were calculated within S and for the groups stored in distilled water. anova and Tukey tests were performed to identify significant differences in PF results and Kruskal-Wallis test and Dunn multiple comparison post hoc test, for D results (α=0.05). For Acron MC denture base shape, FP results were 0.24% (S 50%) and 1.37% (distilled water); for rectangular shape FP was 0.35% (S 75%) and 0.19% (distilled water). For Classico denture base shape, FP results were 0.54% (S 75%) and 1.21% (distilled water); for rectangular shape FP was 0.7% (S 50%) and 1.32% (distilled water). FP results were similar in S and distilled water only for Acron MC rectangular shape (p>0.05). D results in distilled water were statistically higher than S for all groups. The results of the study suggest that an adequate solution for storing specimens must be used to measure porosity by water absorption, based on excluding the plasticising effect.
    Gerodontology 12/2009; 28(2):127-33. · 1.83 Impact Factor
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    ABSTRACT: Small pores of almost uniform shape and size are common in polymeric materials; however, significant porosity can weaken a denture base resin and promote staining, harboring of organisms such as Candida albicans, and bond failures between the artificial tooth and denture base resin. The aim of this study was to investigate the porosity at the interface of one artificial tooth acrylic resin (Trilux, copolymer of polymethyl methacrylate, ethylene glycol dimethacrylate, and color pigments) and three denture base resins: Acron MC (microwave-polymerized), Lucitone 550 (heat-polymerized), and QC-20 (heat-polymerized). Ten specimens of each denture base resin with artificial tooth were processed. After polymerization, specimens were polished and observed under a microscope at 80x magnification. The area of each pore present between artificial tooth and denture base resin was measured using computer software, and the total area of pores per surface was calculated in millimeter square. The Kruskal-Wallis test was performed to compare porosity data (alpha= 0.05). Porosity analysis revealed the average number of pores (n), area range (S, mm(2)), and diameter range (d, mum) for Acron MC (n = 23, S = 0.001 to 0.0056, d = 35 to 267), Lucitone 550 (n = 13, S = 0.001 to 0.005, d = 35 to 79), and QC-20 (n = 19, S = 0.001 to 0.014, d = 35 to 133). The analyses showed that there were no statistically significant differences among the groups (p= 0.7904). Within the limitations of this in vitro study, it was concluded that the denture base resins evaluated did not affect porosity formation at the artificial tooth/denture base resin interface.
    Journal of Prosthodontics 09/2009; 19(1):42-6. · 0.68 Impact Factor
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    ABSTRACT: The purpose of this study was to evaluate the thermocycling effects and shear bond strength of acrylic resin teeth to denture base resins. Three acrylic teeth (Biotone, Trilux, Ivoclar) were chosen for bonding to four denture base resins: microwave-polymerized (Acron MC), heat-polymerized (Lucitone 550 and QC-20), and light-polymerized (Versyo.bond). Twenty specimens were produced for each denture base/acrylic tooth combination and were divided into two groups (n = 10): without thermocycling (control groups) and thermocycled groups submitted to 5000 cycles between 4 and 60 degrees C. Shear strength tests (MPa) were performed with a universal testing machine at a crosshead speed of 1 mm/min. Statistical analysis of the results was carried out with three-way ANOVA and Bonferroni's multiple comparisons post hoc analysis for test groups (alpha = 0.05). The shear bond strengths of Lucitone/Biotone, Lucitone/Trilux, and Versyo/Ivoclar specimens were significantly decreased by thermocycling, compared with the corresponding control groups (p < 0.05). The means of Acron/Ivoclar and Lucitone/Ivoclar specimens increased after thermocycling (p < 0.05). The highest mean shear bond strength value was observed with Lucitone/Biotone in the control group (14.54 MPa) and the lowest with QC-20/Trilux in the thermocycled group (3.69 MPa). Some acrylic tooth/denture base resin combinations can be more affected by thermocycling; effects vary based upon the materials used.
    Journal of Prosthodontics 06/2009; 18(5):438-43. · 0.68 Impact Factor
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    ABSTRACT: Bond failures at the acrylic teeth and denture base resin interface are still a common clinical problem in prosthodontics. The effect of methyl methacrylate (MMA) monomer on the bond strength of three types of denture base resins (Acron MC, Lucitone 550 and QC-20) to two types of acrylic teeth (Biotone and Trilux) was evaluated. Twenty specimens were produced for each denture base resin/acrylic tooth combination and were randomly divided into control (acrylic teeth received no surface treatment) and experimental groups (MMA was applied to the surface of the acrylic teeth for 180 s) and were submitted to shear tests (1 mm/min). Data (MPa) were analyzed using three-way ANOVA/Student's test (α=0.05). MMA increased the bond strength of Lucitone denture base resins and decreased the bond strength of QC-20. No difference was detected for the bond strength of Acron MC base resin after treatment with MMA.
    International Journal of Adhesion and Adhesives. 01/2009;
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    ABSTRACT: To evaluate the pattern of maxillary complete denture movement during chewing for free-end removable partial dentures (RPD) wearers, compared to maxillary and mandibular complete denture wearers. Eighteen edentulous participants (group I) and 10 volunteers with bilateral posterior edentulous mandibles (group II) comprised the sample. Measures of mean denture movement and its variability were obtained by a kinesiographic instrument K6-I Diagnostic System, during the mastication of bread and a polysulphide block. Data were analysed using two-way ANOVA (alpha = 0.05). Upper movement during chewing was significantly lower for group II, regardless of the test food. The test food did not influence the vertical or lateral position of the denture bases, but more anterior dislocation was found when polysulphide blocks were chewed. Group II presented lower intra-individual variability for the vertical axis. Vertical displacement was also more precise with bread as a test food. It can be concluded that mandibular free-end RPD wearers show smaller and more precise movements than mandibular complete denture wearers.
    Gerodontology 09/2008; 26(1):19-25. · 1.83 Impact Factor
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    ABSTRACT: Failure of bonding between acrylic resin teeth and denture base material is a considerable problem for patients who wear complete dentures. The purpose of this study was to evaluate the bond strength between acrylic resins and resin denture teeth with different thermocycling and polymerisation methods. Microwave-polymerised (Onda-Cryl), heat-polymerised (Clássico) and autopolymerising (Jet) acrylic resins and resin denture tooth (Biotone) were used. The acrylic resins were polymerised according to the following: (A) microwave - fast cycle, Onda-Cryl; (B) microwave - long cycle, Onda-Cryl; (C) microwave - manufacturer's cycle, Onda-Cryl; (T) water bath - long cycle, Clássico; and (Q) bench polymerisation cycle, Jet. Twenty specimens were prepared for each polymerisation method. Ten were thermocycled, and 10 did not receive thermocycling. For the purpose of the study, a shear test was used. Data were analysed with the Kruskal-Wallis test and Dunn's multiple comparisons test (p = 0.05). Cycles B, C and T were similar (p > 0.05), and had statistically higher bonding values than cycles A and Q (p < 0.05) for the thermocycled and non-thermocycled groups. For all cycles, there were no statistically significant differences between thermocycled and non-thermocycled groups (p > 0.05), except for cycle Q (p = 0.0038). Thermocycling decreased the bond strength, but not significantly for microwave and heat-polymerised cycles. Regarding the bond strength of denture teeth to acrylic resin, the fast microwave polymerisation cycle should be avoided when polymerising Onda-Cryl acrylic resin. In addition, Jet acrylic resin is not adequate for use in denture repair.
    Gerodontology 04/2008; 25(4):237-44. · 1.83 Impact Factor
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    ABSTRACT: This study evaluated the influence of polymerization cycle and thickness of maxillary complete denture bases on the porosity of acrylic resin. Two heat-activated denture base resins--one conventional (Clássico) and one designed for microwave polymerization (Onda-Cryl)--were used. Four groups were established, according to polymerization cycles: A (Onda-Cryl, short microwave cycle), B (Onda-Cryl, long microwave cycle), C (Onda-Cryl, manufacturing microwave cycle), and T (Clássico, water bath). Porosity was evaluated for different thicknesses (2.0, 3.5, and 5.0 mm; thicknesses I, II, and III, respectively) by measurement of the specimen volume before and after its immersion in water. The percent porosity data were submitted to Kruskal-Wallis for comparison among the groups. The Kruskal-Wallis test detected that the combinations of the different cycles and thicknesses showed significant differences, and the mean ranks of percent porosity showed differences only in the thinnest (2.0 mm) microwave-polymerized specimens (A = 53.55, B = 40.80, and C = 90.70). Thickness did not affect the results for cycle T (I = 96.15, II = 70.20, and III = 82.70), because porosity values were similar in the three thicknesses. Microwave polymerization cycles and the specimen thickness of acrylic resin influenced porosity. Porosity differences were not observed in the polymerized resin bases in the water bath cycle for any thickness.
    Journal of Prosthodontics 03/2008; 17(2):125-9. · 0.68 Impact Factor
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    ABSTRACT: The aims of this study were to evaluate the reliability and to validate a Brazilian version of Oral Health Impact Profile for assessing edentulous subjects (OHIP-EDENT), an inventory for measuring oral health-related quality of life of edentulous subjects. The sample comprised 65 complete denture wearers (23 men, mean age of 69.1 +/- 10.3 years). The translated OHIP-EDENT was applied on two occasions with a washout period of 3 months. Reliability was assessed by an internal consistency analysis and a test-retest approach. A preliminary validation process was conducted by a qualitative approach/interview. Results of internal consistency showed a Cronbach's alpha of 0.86 or 0.90 for the first or second appointment respectively. Through the test-retest analysis, an intra-class correlation coefficient of 0.57 was found, and individual answers reflected a broad range of agreement. Interviewed volunteers (n = 6) comprehended most questions well. In conclusion, the Brazilian version of OHIP-EDENT is adequate for assessing the oral health-related quality of life for edentulous subjects.
    Journal of Oral Rehabilitation 12/2007; 34(11):821-6. · 2.34 Impact Factor
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    ABSTRACT: Despite the large number of studies addressing the effect of microwave polymerization on the properties of acrylic resin, this method has received limited clinical acceptance. This study evaluated the influence of microwave polymerization on the flexural strength of a denture base resin. A conventional heat-polymerized (Clássico), a microwave-polymerized (Onda-Cryl) and a autopolymerizing acrylic (Jet) resins were used. Five groups were established, according to polymerization cycles: A, B and C (Onda-Cryl, short cycle - 500W/3 min, long - 90W/13 min + 500W/90 sec, and manufacturing microwave cycle - 320W/3 min + 0W/3 min + 720W/3 min); T (Clássico, water bath cycle - 74 degrees C/9h) and Q (Jet, press chamber cycle - 50 degrees C/15 min at 2 bar). Ten specimens (65 x 10 x 3.3mm) were prepared for each cycle. The flexural strength of the five groups was measured using a three-point bending test at a cross-head speed of 5 mm/min. Flexural strength values were analyzed by one-way ANOVA and the Tukey's test was performed to identify the groups that were significantly different at 5% level. The microwave-polymerized groups showed the highest means (p<0.05) for flexural strength (MPa) (A = 106.97 +/- 5.31; B = 107.57 +/- 3.99; C = 109.63 +/- 5.19), and there were no significant differences among them. The heat-polymerized group (T) showed the lowest flexural strength means (84.40 +/- 1.68), and differ significantly from all groups. The specimens of a microwavable denture base resin could be polymerized by different microwave cycles without risk of decreasing the flexural strength.
    Journal of applied oral science: revista FOB 10/2007; 15(5):424-8. · 0.39 Impact Factor

Publication Stats

109 Citations
21.59 Total Impact Points

Institutions

  • 2012
    • Universidade Paulista
      San Paulo, São Paulo, Brazil
  • 2008–2012
    • São Paulo State University
      • Departamento de Materiais Odontológicos e Prótese (Araçatuba)
      Assis, Estado de Sao Paulo, Brazil
  • 2007
    • University of São Paulo
      San Paulo, São Paulo, Brazil