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Campanha NH, Pavarina AC, Jorge JH, Vergani CE, Machado AL, Giampaolo ET. The effect of long-term disinfection procedures on hardness property of resin denture teeth. Gerodontology 2011; 29:e571-6. [PMID: 21771050 DOI: 10.1111/j.1741-2358.2011.00520.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The aim of the study was to evaluate the effect of long-term disinfection procedures on the Vickers hardness (VHN) of acrylic resin denture teeth. MATERIAL AND METHODS Five acrylic resin denture teeth (Vipi Dent Plus-V, Trilux-T, Biolux-B, Postaris-P and Artiplus-A) and one composite resin denture teeth (SR-Orthosit-O) were embedded in heat-polymerised acrylic resin within polyvinylchloride tubes. Specimens were stored in distilled water at 37°C for 48 h. Measurements of hardness were taken after the following disinfection procedures: immersion for 7 days in 4% chlorhexidine gluconate or in 1% sodium hypochlorite (CIm and HIm group, respectively) and seven daily cycles of microwave sterilisation at 650 W for 6 min (MwS group). In the WIm group, specimens were maintained in water during the time used to perform the disinfection procedures (7 days). Data were analysed with anova followed by the Bonferroni procedure (α = 0.01). RESULTS Microwave disinfection decreased the hardness of all acrylic resin denture teeth (p < 0.001). Immersion for 7 days in 4% chlorhexidine gluconate or distilled water had significant effect on the hardness of the acrylic resin denture teeth A (p < 0.01), and 1% sodium hypochlorite on teeth T (p < 0.01). All disinfection procedures decrease the hardness of the composite resin denture teeth (p < 0.01). Teeth O exhibited the highest and teeth V the lowest hardness values in the control group (p < 0.01). CONCLUSIONS Disinfection procedures changed the hardness of resin denture teeth.
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Dovigo LN, Pavarina AC, Ribeiro APD, Brunetti IL, Costa CADS, Jacomassi DP, Bagnato VS, Kurachi C. Investigation of the photodynamic effects of curcumin against Candida albicans. Photochem Photobiol 2011; 87:895-903. [PMID: 21517888 DOI: 10.1111/j.1751-1097.2011.00937.x] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study describes the association of curcumin with light emitting diode (LED) for the inactivation of Candida albicans. Suspensions of Candida were treated with nine curcumin concentrations and exposed to LED at different fluences. The protocol that showed the best outcomes for Candida inactivation was selected to evaluate the effect of the preirradiation time (PIT) on photodynamic therapy (PDT) effectiveness, the uptake of curcumin by C. albicans cells and the possible involvement of singlet oxygen in the photodynamic action. Curcumin-mediated PDT was also assessed against biofilms. In addition to the microbiological experiments, similar protocols were tested on a macrophage cell line and the effect was evaluated by Methyltetrazolium assay (MTT) and SEM analysis. The optical properties of curcumin were investigated as a function of illumination fluence. When compared with the control group, a statistically significant reduction in C. albicans viability was observed after PDT (P < 0.05), for both planktonic and biofilm cultures. Photodynamic effect was greatly increased with the presence of curcumin in the surrounding media and the PIT of 20 min improved PDT effectiveness against biofilms. Although PDT was phototoxic to macrophages, the therapy was more effective in inactivating the yeast cell than the defense cell. The spectral changes showed a high photobleaching rate of curcumin.
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Sanitá PV, Pavarina AC, Giampaolo ET, Silva MM, Mima EGDO, Ribeiro DG, Vergani CE. Candida spp. prevalence in well controlled type 2 diabetic patients with denture stomatitis. ACTA ACUST UNITED AC 2011; 111:726-33. [DOI: 10.1016/j.tripleo.2011.02.033] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 02/14/2011] [Accepted: 02/19/2011] [Indexed: 10/18/2022]
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Reis JMSN, Giampaolo ET, Pavarina AC, Machado AL, Erxleben J, Vergani CE. Exothermic behavior, degree of conversion, and viscoelastic properties of experimental and commercially available hard chairside reline resins. J Appl Polym Sci 2011. [DOI: 10.1002/app.34268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Machado AL, Giampaolo ET, Pavarina AC, Jorge JH, Vergani CE. Surface roughness of denture base and reline materials after disinfection by immersion in chlorhexidine or microwave irradiation. Gerodontology 2011; 29:e375-82. [DOI: 10.1111/j.1741-2358.2011.00484.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Dovigo LN, Pavarina AC, Mima EGDO, Giampaolo ET, Vergani CE, Bagnato VS. Fungicidal effect of photodynamic therapy against fluconazole-resistant Candida albicans and Candida glabrata. Mycoses 2011; 54:123-30. [PMID: 19889173 DOI: 10.1111/j.1439-0507.2009.01769.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although photodynamic therapy (PDT) has shown great promise for the inactivation of Candida species, its effectiveness against azole-resistant pathogens remains poorly documented. This in vitro study describes the association of Photogem® (Photogem, Moscow, Russia) with LED (light emitting diode) light for the photoinactivation of fluconazole-resistant (FR) and American Type Culture Collection (ATCC) strains of Candida albicans and Candida glabrata. Suspensions of each Candida strain were treated with five Photogem® concentrations and exposed to four LED light fluences (14, 24, 34 or 50 min of illumination). After incubation (48 h at 37 °C), colonies were counted (CFU ml(-1)). Single-species biofilms were generated on cellulose membrane filters, treated with 25.0 mg l(-1) of Photogem® and illuminated at 37.5 J cm(-2). The biofilms were then disrupted and the viable yeast cells present were determined. Planktonic suspensions of FR strains were effectively killed after PDT. It was observed that the fungicidal effect of PDT was strain-dependent. Significant decreases in biofilm viability were observed for three strains of C. albicans and for two strains of C. glabrata. The results of this investigation demonstrated that although PDT was effective against Candida species, fluconazole-resistant strains showed reduced sensitivity to PDT. Moreover, single-species biofilms were less susceptible to PDT than their planktonic counterparts.
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Mima EGDO, Pavarina AC, da Silveira Vargas F, Giampaolo ET, Machado AL, Vergani CE. Effectiveness of chlorhexidine on the disinfection of complete dentures colonised with fluconazole-resistant Candida albicans: in vitro study. Mycoses 2011; 54:e506-12. [DOI: 10.1111/j.1439-0507.2010.01968.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ribeiro DG, Pavarina AC, Dovigo LN, de Oliveira Mima EG, Machado AL, Bagnato VS, Vergani CE. Photodynamic inactivation of microorganisms present on complete dentures. A clinical investigation. Lasers Med Sci 2011; 27:161-8. [DOI: 10.1007/s10103-011-0912-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 03/04/2011] [Indexed: 11/27/2022]
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Trindade FZ, Pavarina AC, Ribeiro APD, Bagnato VS, Vergani CE, de Souza Costa CA. Toxicity of photodynamic therapy with LED associated to Photogem®: An in vivo study. Lasers Med Sci 2011; 27:403-11. [DOI: 10.1007/s10103-011-0909-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 03/04/2011] [Indexed: 11/29/2022]
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Machado AL, Giampaolo ET, Vergani CE, Pavarina AC, da Silva Lopes Salles D, Jorge JH. Weight loss and changes in surface roughness of denture base and reline materials after simulated toothbrushing in vitro. Gerodontology 2011; 29:e121-7. [DOI: 10.1111/j.1741-2358.2010.00422.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Izumida FE, Ribeiro RC, Giampaolo ET, Machado AL, Pavarina AC, Vergani CE. Effect of microwave disinfection on the surface roughness of three denture base resins after tooth brushing. Gerodontology 2011; 28:277-82. [DOI: 10.1111/j.1741-2358.2010.00393.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ribeiro DG, Jorge JH, Varjão FM, Pavarina AC, Garcia PPNS. Evaluation of partially dentate patients’ knowledge about caries and periodontal disease. Gerodontology 2011; 29:e253-8. [DOI: 10.1111/j.1741-2358.2011.00460.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wady AF, Machado AL, Vergani CE, Pavarina AC, Giampaolo ET. Impact strength of denture base and reline acrylic resins subjected to long-term water immersion. Braz Dent J 2011; 22:56-61. [DOI: 10.1590/s0103-64402011000100010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Water may influence the mechanical properties of the acrylic resins. Thus, the effect of water storage on the impact strength (IS) of one denture base (Lucitone 550 - L) and four reline resins (Tokuyama Rebase II - T; UfiGel Hard - U; Kooliner - K; New Truliner - NT) was evaluated. Bars of L were made (60 x 6 x 2 mm) and relined (2 mm) with T, U, K, NT and L. Intact specimens of each material (60 x 6 x 4 mm) were also fabricated for comparative purposes. Specimens were submitted to Charpy impact tests without water storage (control) and after immersion in water for 7, 90 and 180 days. Data (kJ/m²) analyzed by two-way ANOVA and Tukey's test (p=0.05) revealed that after 90 days, U exhibited an increase in the IS (0.93) compared to 7 days (0.58). K (1.48) and L/K (7.21) exhibited a decrease at the 7-day period (1.01 and 3.23, respectively). NT (0.60) showed an increase in the IS after 180 days (1.52), whereas L/NT (7.70) showed a decrease (3.17). Water immersion improved the IS of U and NT, and decreased the IS of K, L/K, and L/NT. Water may affect differently the IS of acrylic resins and, consequently, the resistance to fracture of relined denture bases.
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Chaves CDAL, Machado AL, Carlos IZ, Giampaolo ET, Pavarina AC, Vergani CE. Cytotoxicity of monomers, plasticizer and degradation by-products released from dental hard chairside reline resins. Dent Mater 2010; 26:1017-23. [DOI: 10.1016/j.dental.2010.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 06/25/2010] [Indexed: 10/19/2022]
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Vergani CE, Seó RS, Reis JM, Giampaolo ET, Pavarina AC, Machado AL. Effect of water storage on the shear strength and fatigue limit of the reline resin bond to denture base resins. THE JOURNAL OF ADHESIVE DENTISTRY 2010; 12:319-327. [PMID: 20157660 DOI: 10.3290/j.jad.a17652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
PURPOSE This study evaluated the effect of water storage (WS) on the shear bond strength (SBS) and shear bond fatigue limit (SBFL) between denture base and reline resins. In addition, a possible correlation between SBS and SBFL was evaluated. MATERIALS AND METHODS Two denture base (Lucitone 550-L and Acron MC-AC) and two reline resins (Ufi Gel Hard- UGH and Tokuso Rebase Fast-TR) were selected. Cylinders (20 x 20 mm) of each denture base resin were processed, and the reline resins were packed on the bonding surfaces using a split mold (3.5 x 5.0 mm). Specimens of each denture base-reline resin combination were subjected to shear forces (0.5 mm/min) until fracture. A staircase approach was used to determine the SBFL. Specimens were submitted to either 10,000 cycles (5.0 Hz) or until fracture. For both SBS and SBFL, specimens were tested after relining (control) and after 30 days of WS. Data (MPa) were analyzed with 2-way ANOVA and Tukey's tests (α = 0.05). To test for a possible correlation between the SBS and SBFL, a linear regression analysis was performed. RESULTS WS significantly increased (p < 0.05) the SBS of AC-TR and AC-UGH and the SBFL of AC-TR, AC-UGH and LUGH. After WS, UGH produced higher (p < 0.05) SBS than TR, regardless of the denture base resin used. Regardless of the experimental groups and the denture base resins used, UGH produced higher (p < 0.05) SBFL than TR specimens. A strong positive linear correlation (r(2) = 0.949) was observed between the SBS and SBFL. CONCLUSION Overall, UGH promoted the highest SBS and SBFL. WS increased the SBS and SBFL of the AC relined specimens. A positive correlation was observed between the two variables.
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Almilhatti HJ, Giampaolo ET, Machado AL, Pavarina AC, Vergani CE. Infiltração marginal em facetas estéticas de resina composta em próteses parciais fixas. BRAZILIAN DENTAL SCIENCE 2010. [DOI: 10.14295/bds.2002.v5i1.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Diferentes materiais estéticos e sistemas de união têm sido desenvolvidos com o objetivo de reduzir a infiltração marginal na interface resina-metal de coroas. O presente estudo avaliou esse fenômeno utilizando corpos-de-prova confeccionados com três diferentes resinas e uma liga de Ni-Cr. Após sua confecção foram armazenados em água destilada a 37oC por 24 horas e, em seguida, submetidos a 100 ciclos alternados em água nos respectivos tempos e temperaturas: 15 segundos a 60}2°C e 15 segundos a 12}2°C. Após essa etapa foram colocados em solução aquosa de Rodamina B a 0,2% por 24 horas. Posteriormente, foram seccionados em 4 setores expondo-se as áreas infiltradas, que foram avaliadas em um perfilômetro. À vista dos resultados obtidos e de acordo com a metodologia empregada, concluiu-se que: ocorreu microinfiltração em todas as situações; a maior infiltração ocorreu com o material SRChromasit.
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Basso MFM, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Compagnoni MA. Influence of microwave disinfection on the linear dimensional stability of complete dentures: a clinical study. INT J PROSTHODONT 2010; 23:318-320. [PMID: 20617219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This clinical study evaluated the effect of two microwave disinfection protocols at 650 W for 3 minutes (group 1, once a week; group 2, three times a week) on the linear dimensional stability of complete dentures. Measurements were taken across four reference points: before the first microwave disinfection (baseline) and after each week of disinfection. Furthermore, the dentures were monitored clinically. Group 2 showed significantly greater shrinkage than group 1 in all evaluated weeks. During clinical monitoring, no significant findings were observed. Even though dimensional changes occurred, the clinical evaluation did not yield any changes in either group.
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Basso MFM, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Ribeiro RC. Influence of Microwave Disinfection on the Dimensional Stability of Denture Reline Polymers. J Prosthodont 2010; 19:364-8. [DOI: 10.1111/j.1532-849x.2010.00583.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Dovigo LN, Pavarina AC, Ribeiro DG, Adriano CS, Bagnato VS. Photodynamic inactivation of four Candida species induced by photogem(®). Braz J Microbiol 2010; 41:42-9. [PMID: 24031462 PMCID: PMC3768607 DOI: 10.1590/s1517-83822010000100009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 06/23/2009] [Accepted: 08/23/2009] [Indexed: 12/29/2022] Open
Abstract
This study evaluated the in vitro susceptibility of C. albicans, C. dubliniensis, C. tropicalis and C. krusei to photodynamic therapy (PDT) induced by Photogem®and light emitted diode (LED). Suspensions of each Candida strain were treated with three photosensitizer (PS) concentrations (10, 25 and 50 mg/L) and exposed to 18, 25.5 and 37.5 J/cm2 LED light fluences (λ ~ 455 nm). Control suspensions were treated only with PS concentrations, only exposed to the LED light fluences or not exposed to LED light or PS. Sixteen experimental conditions were obtained and each condition was repeated three times. From each sample, serial dilutions were obtained and aliquots were plated on Sabouraud Dextrose Agar. After incubation of plates (37 °C for 48 hours), colonies were counted (cfu/mL) and the data were statistically analyzed by ANOVA and the Tukey test (α=0.05). Complete killing of C. albicans was observed after 18 J/cm2 in association with 50 mg/L of PS. C. dubliniensis were inactivated after 18 J/cm2 using 25 mg/L of PS. The inactivation of C. tropicalis was observed after photosensitization with 25 mg/L and subsequent illumination at 25.5 J/cm2. For C. krusei, none of the associations between PS and light resulted in complete killing of this species. PDT proved to be effective for the inactivation of C. albicans, C. dubliniensis and C. tropicalis. In addition, reduction in the viability of C. krusei was achieved with some of the PS and light associations.
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da Cruz Perez LE, Machado AL, Canevarolo SV, Vergani CE, Giampaolo ET, Pavarina AC. Effect of reline material and denture base surface treatment on the impact strength of a denture base acrylic resin. Gerodontology 2010; 27:62-9. [DOI: 10.1111/j.1741-2358.2009.00292.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Giampaolo ET, Jorge JH, Machado AL, Pavarina AC, Vergani CE. Effect of thermal cycling on microleakage between hard chairside relines and denture base acrylic resins. Gerodontology 2010; 28:121-6. [PMID: 20082644 DOI: 10.1111/j.1741-2358.2009.00332.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES Microleakage is a pre-stage of debonding between hard chairside relines and denture base acrylic resins. Therefore, it is important to assess them with regard to the longevity of the relined denture. This study investigated the effect of thermal cycling on the microleakage at the interface of three hard chairside reline resins and three denture base resins. MATERIAL AND METHODS Rectangular bars (12 mm × 3 mm × 3 mm) of Lucitone 550, Acron MC and QC 20 were made and relined with Kooliner, Tokuyama Rebase Fast II and Ufi Gel Hard, Lucitone 550, Acron MC and QC 20 resins. Specimens were divided into one control and two test groups (n=10). In specimens of the control group, the microleakage was performed after the reline procedure. In Test Group 1, the specimens were stored for 24 h in distilled water at room temperature and in Test Group 2; the specimens were thermal cycled from 5 to 55°C for 5000 cycles with a 30-s dwell time. Subsequently, all specimens were immersed in 50% silver nitrate solutions for 24h. All specimens were sectioned longitudinally into three fractions and the lateral sections were examined (n=20). Silver nitrate stain penetration was examined under a stereoscopic lens with ×30 magnification, and the images were captured. Leica Qwin image analysis software was used to determine microleakage at the interface of the materials. Data were analysed using the Kruskal-Wallis test at a 95% level of significance. RESULTS For all cycles, there were no statistically significant differences between thermal cycled and non-thermal cycled groups (p>0.05). CONCLUSION It can be concluded that thermal cycling had no effect on the microleakage.
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Mima EGDO, Pavarina AC, Dovigo LN, Vergani CE, Costa CADS, Kurachi C, Bagnato VS. Susceptibility of Candida albicans to photodynamic therapy in a murine model of oral candidosis. ACTA ACUST UNITED AC 2010; 109:392-401. [PMID: 20060338 DOI: 10.1016/j.tripleo.2009.10.006] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/25/2009] [Accepted: 10/04/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE In vivo studies of antimicrobial PDT in animal models of oral candidosis are scarce and the association of porphyrin and LED light has not been evaluated for in vivo photoinactivation of Candida. In this study the effectiveness of photodynamic therapy (PDT) on the inactivation of Candida albicans in vivo was evaluated. STUDY DESIGN Seventy-one 6-week-old female Swiss mice were immunosuppressed, provided tetracycline to their drinking water, then orally swabbed with a suspension of C. albicans (10(7) CFU/mL). Four days after oral inoculation, PDT was performed on the dorsum of the tongue after topical administration of Photogem at 400, 500, or 1000 mg/L and followed 30 minutes later by illumination with LED light (305 J/cm(2)) at 455 or 630 nm (n = 5 each). After swabbing to recover yeast from the tongue, the number of surviving yeast cells was determined (CFU/mL) and analyzed by ANOVA and Holm-Sidak tests (P < .05). Animals were humanely killed, and the tongues surgically removed and processed for histological evaluation of presence of yeast and inflammatory reaction. RESULTS PDT resulted in a significant reduction in C. albicans recovered from the tongue (P < .001) when compared with mice from the positive control group. There was no difference between the concentrations of Photogem and LED light wavelengths used. Histological evaluation of the tongue revealed that PDT causes no significant adverse effects to the local mucosa. CONCLUSION PDT promoted significant reduction in the viability of C. albicans biofilm without harming the tongue tissue.
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Jorge JH, Giampaolo ET, Vergani CE, Machado AL, Pavarina AC, Carlos IZ. Effect of post-polymerization heat treatments on the cytotoxicity of two denture base acrylic resins. J Appl Oral Sci 2009; 14:203-7. [PMID: 19089074 PMCID: PMC4327198 DOI: 10.1590/s1678-77572006000300011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Accepted: 06/06/2006] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION Most denture base acrylic resins have polymethylmethacrylate in their composition. Several authors have discussed the polymerization process involved in converting monomer into polymer because adequate polymerization is a crucial factor in optimizing the physical properties and biocompatibility of denture base acrylic resins. To ensure the safety of these materials, in vitro cytotoxicity assays have been developed as preliminary screening tests to evaluate material biocompatibility. (3)H-thymidine incorporation test, which measures the number of cells synthesizing DNA, is one of the biological assays suggested for cytotoxicity testing. AIM The purpose of this study was to investigate, using (3)H-thymidine incorporation test, the effect of microwave and water-bath post-polymerization heat treatments on the cytotoxicity of two denture base acrylic resins. MATERIALS AND METHODS Nine disc-shaped specimens (10 x 1 mm) of each denture base resin (Lucitone 550 and QC 20) were prepared according to the manufacturers' recommendations and stored in distilled water at 37 degrees C for 48 h. The specimens were assigned to 3 groups: 1) post-polymerization in a microwave oven for 3 min at 500 W; 2) post-polymerization in water-bath at 55 degrees C for 60 min; and 3) without post-polymerization. For preparation of eluates, 3 discs were placed into a sterile glass vial with 9 mL of Eagle's medium and incubated at 37 degrees C for 24 h. The cytotoxic effect of the eluates was evaluated by (3)H-thymidine incorporation. RESULTS The results showed that the components leached from the resins were cytotoxic to L929 cells, except for the specimens heat treated in water bath (p<0.05). Compared to the group with no heat treatment, water-bath decreased the cytotoxicity of the denture base acrylic resins. CONCLUSION The in vitro cytotoxicity of the tested denture base materials was not influenced by microwave post-polymerization heat treatment.
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Jorge JH, Giampaolo ET, Vergani CE, Pavarina AC, Machado AL, Carlos IZ. Effect of microwave postpolymerization treatment and of storage time in water on the cytotoxicity of denture base and reline acrylic resins. QUINTESSENCE INTERNATIONAL (BERLIN, GERMANY : 1985) 2009; 40:e93-e100. [PMID: 20157935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVES To evaluate the effect of microwave postpolymerization heat treatment and water storage time on the cytotoxicity of denture base and reline acrylic resins. METHOD AND MATERIALS Sample disks of 6 acrylic resins were fabricated under aseptic conditions (Kooliner, GC; Tokuyama Rebase II, Tokuyama Dental; New Truliner, Bosworth; Acron MC, GC; Lucitone 550, Dentsply; QC 20, Dentsply). The denture base acrylic resin samples were stored in water for 24 and 48 hours at 37 degrees C. The fabricated samples were further subdivided into 2 groups: (1) samples without heat treatment and (2) samples treated in a microwave. The 3H-thymidine incorporation test was used to determine the cytotoxicity of the materials. The data were statistically analyzed using the incomplete 3-way ANOVA and Tukey HSD tests (P < .05). RESULTS Microwave postpolymerization heat treatment improved the biocompatibility of Tokuyama Rebase II. Tokuyama Rebase II without heat treatment and Acron MC in both experimental groups were graded as slightly cytotoxic in the group without water storage. The other resins were graded as noncytotoxic. After 24 hours of immersion in water, all materials were graded as noncytotoxic. After water storage for 48 hours, Acron MC without heat treatment and QC 20 in both experimental groups were graded as slightly cytotoxic. Lucitone 550 was graded as noncytotoxic in all experimental groups. CONCLUSION Microwave irradiation may be considered an alternative to reduce the cytotoxicity of Tokuyama Rebase II. Dental practitioners should choose Lucitone 550 processed with terminal boiling stage.
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Dovigo LN, Pavarina AC, Ribeiro DG, de Oliveira JA, Vergani CE, Machado AL. Microwave Disinfection of Complete Dentures ContaminatedIn Vitrowith Selected Bacteria. J Prosthodont 2009; 18:611-7. [DOI: 10.1111/j.1532-849x.2009.00489.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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