RESUMO

This study aimed to evaluate the influence of the Er,Cr:YSGG irradiation and 980-nm diode lasers on the surface roughness (SR) and volume loss (VL) of dentin subjected to cariogenic challenge. Subsequently, 130 specimens of bovine dentin were divided into the following 13 groups: NT: no treatment; FG: fluoride gel; FV: fluoride varnish; Di: 980-nm diode; Di + FG; Di + FV; FG + D; FV + Di; Er: Er,Cr:YSGG; Er + FG; Er + FV; FG + Er and FV + Er. Er,Cr:YSGG laser parameters were as follows: 0.25 W; 5.0 Hz; 4.46 J/cm2 without water and 55% air. Furthermore, the 980-nm diode laser parameters were 2.0 W; 2.0 Hz; 21.41 J/cm2. The samples from each group were subjected to pH cycling. A confocal laser scanning microscope was used to evaluate SR and VL. Difference between the volume of the reference and treated areas + DES/RE was used to determine SR and VL. The mean values of the different groups were subjected to analysis of variance and Tukey's post-hoc test. The VL values were analyzed using the Kruskal-Wallis and Dunn post-hoc test (p < 0.05). The SR of the reference area did not show a statistically significant 1807-3107-bor-38-e025treatment and cariogenic challenge (p > 0.05). Moreover, VL in the FV + Di and FV + Er groups showed a statistically significant difference compared with areas submitted to different types of treatment and cariogenic challenge (p > 0.05). Er,Cr:YSGG and 980-nm diode lasers associated with fluoride varnishes decreased dentin VL in bovine teeth submitted to cariogenic challenge.

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RESUMO

Abstract This study aimed to evaluate the influence of the Er,Cr:YSGG irradiation and 980-nm diode lasers on the surface roughness (SR) and volume loss (VL) of dentin subjected to cariogenic challenge. Subsequently, 130 specimens of bovine dentin were divided into the following 13 groups: NT: no treatment; FG: fluoride gel; FV: fluoride varnish; Di: 980-nm diode; Di + FG; Di + FV; FG + D; FV + Di; Er: Er,Cr:YSGG; Er + FG; Er + FV; FG + Er and FV + Er. Er,Cr:YSGG laser parameters were as follows: 0.25 W; 5.0 Hz; 4.46 J/cm2 without water and 55% air. Furthermore, the 980-nm diode laser parameters were 2.0 W; 2.0 Hz; 21.41 J/cm2. The samples from each group were subjected to pH cycling. A confocal laser scanning microscope was used to evaluate SR and VL. Difference between the volume of the reference and treated areas + DES/RE was used to determine SR and VL. The mean values of the different groups were subjected to analysis of variance and Tukey's post-hoc test. The VL values were analyzed using the Kruskal-Wallis and Dunn post-hoc test (p < 0.05). The SR of the reference area did not show a statistically significant 1807-3107-bor-38-e025treatment and cariogenic challenge (p > 0.05). Moreover, VL in the FV + Di and FV + Er groups showed a statistically significant difference compared with areas submitted to different types of treatment and cariogenic challenge (p > 0.05). Er,Cr:YSGG and 980-nm diode lasers associated with fluoride varnishes decreased dentin VL in bovine teeth submitted to cariogenic challenge.

RESUMO

OBJECTIVE: This study evaluated the effect of different glucose concentration on biofilm formation of Candida albicans and Candida glabrata strains isolated from diabetic and non-diabetic individuals. METHODS: The study was divided into two stages: (I) selection and identification of 48 C. albicans and C. glabrata strains by polymerase chain reaction followed by restriction fragment length polymorphism analysis (PCR/RFLP); (II) evaluation of biofilm formation by means of viability rates (colony-forming units), biofilm dry matter (mg) and biofilm-covered areas (µm2). Statistical comparisons were performed through nonparametric analysis of longitudinal data in factorial experiments with pairwise comparisons using Friedman Conover's test (α = 0.05). RESULTS: All the Candida spp. had their identifications confirmed by PCR/RFLP. C. albicans biofilm of strains from diabetic individuals cultivated in different glucose concentration showed higher viability rates than strains from non-diabetic individuals. No difference was observed on viability of C. glabrata biofilm. Regarding biofilm dry matter, C. albicans biofilm of strains from diabetic individuals cultivated in different glucose concentration showed lower amount in weight than strains from non-diabetic individuals. In C. glabrata strains, this result was only observed in biofilms cultivated with no glucose supplementation. With regard to biofilm-covered areas, only glucose supplementation and non-diabetic condition showed a positive effect on C. albicans biofilm development, and no condition affected C. glabrata biofilm formation. CONCLUSION: The strain type (C. albicans and C. glabrata) isolated from diabetic and non-diabetic individuals influenced on biofilm formation, but glucose supplementation did not.

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The acrylic resin used for the prosthesis base accumulates biofilm, causing diseases such as stomatitis. The addition of some nanoparticles promotes antimicrobial action. This study incorporated the nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) to the acrylic resin by two methods and evaluated the cytotoxicity for human gingival fibroblasts (HGF) and the released silver and vanadium ions. The concentrations of 0.5, 1, 2.5, and 5% of AgVO3 was incorporated by vacuum spatulation and polymeric film. The vacuum spatulation was performed for 60 s using the Turbomix equipment, and the polymeric film was obtained from the polymer solubilization in chloroform, the film was subjected to a cryogenic grinding, and the powder obtained was manually mixed at the monomer. HGF cell viability was assessed after 24 hours, 7 and 14 days by the MTT assay. The release of silver (Ag) and vanadium (V) ions were quantified by inductively coupled plasma mass spectrometry after 30 days. Kruskal-Wallis and Dunn's test were applied (α = 0.05). The HGF viability was inversely proportional to the incubation time. Both incorporation techniques and the negative and positive control groups presented significant statistical differences (p<0.05). The experimental groups presented no statistical difference compared to the negative control (p>0.05), except the vacuum spatulation group with 5% of AgVO3 that showed greater viability than the negative control (p=0.013) in 24 hours. The release of Ag and V ions was proportional to the concentration of AgVO3 The 5% group presented a significant difference compared to the other groups (p<0.05). In conclusion, the acrylic resin with and without the AgVO3 incorporation had a small cytotoxic potential for HGF in 24 hours, with a lower viability in longer contact times; the release of Ag and V ions was proportional to the concentration of AgVO3, not influencing cell viability. (AU)

A resina acrílica utilizada para a base da prótese acumula biofilme, causando doenças como a estomatite. A adição de algumas nanopartículas promove ação antimicrobiana. Este estudo incorporou o vanadato de prata nanoestruturado decorado com nanopartículas de prata (AgVO3) à resina acrílica por dois métodos e avaliou a citotoxicidade para fibroblastos gengivais humanos (HGF) e os íons prata e vanádio liberados. As concentrações de 0,5%, 1%, 2,5% e 5% de AgVO3 foram incorporadas por espatulação a vácuo e filme polimérico. A espatulação a vácuo foi realizada por 60 s no equipamento Turbomix, e o filme polimérico foi obtido a partir da solubilização do polímero em clorofórmio, o filme foi submetido a uma moagem criogênica e o pó obtido foi misturado manualmente ao monômero. A viabilidade celular de HGF foi avaliada após 24 horas, 7 e 14 dias pelo ensaio de MTT. A liberação de íons prata (Ag) e vanádio (V) foi quantificada por espectrometria de massa com plasma indutivamente acoplado após 30 dias. Os testes de Kruskal-Wallis e Dunn foram aplicados (α=0,05). A viabilidade de HGF foi inversamente proporcional ao tempo de incubação. As técnicas de incorporação e os grupos controle negativo e positivo apresentaram diferença estatisticamente significante (p<0,05). Os grupos experimentais não apresentaram diferença estatística em relação ao controle negativo (p>0,05), exceto o grupo de espatulação a vácuo com 5% de AgVO3 que apresentou maior viabilidade que o controle negativo (p = 0,013) em 24 horas. A liberação de íons Ag e V foi proporcional à concentração de AgVO3. O grupo 5% apresentou diferença significativa em relação aos demais grupos (p <0,05). Em conclusão, a resina acrílica com e sem a incorporação de AgVO3 apresentou um pequeno potencial citotóxico para o HGF em 24 horas, com menor viabilidade nos tempos de maior contato, e a liberação de íons Ag e V foi proporcional à concentração de AgVO3, não influenciando na viabilidade celular. (AU)

RESUMO

This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn's post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 µm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

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RESUMO

Abstract This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn's post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 μm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

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The incorporation of antimicrobial agents may influence the mechanical properties of acrylic resins. Thus, the use of these agents only in regions of dental prostheses subject to greater contamination may be an alternative. This study evaluates the effect of thermomechanical fatigue on the bond strength between a conventional and an experimental acrylic resin incorporated with nanostructured silver vanadate decorated with silver nanoparticles (AgVO3). 60 specimens (Ø13mm x 23mm height) in self-curing resin were obtained and divided into groups according to the experimental resin incorporated with AgVO3 (Ø4mm x 6mm height): G1­Conventional x Conventional, G2­Conventional x 2.5% of AgVO3, G3­Conventional x 5% of AgVO3. Ten samples of each group were subjected to bond strength analysis after manufacture, and 10 were previously submitted to 1.200.000 cycles with 98N load and 2Hz/second frequency and alternating baths of 5 ºC, 37ºC and 55 ºC. The fracture area was analyzed. The data were submitted to analysis of variance of two-factors with Bonferroni adjustment for post hoc comparisons (α=0.05) was used. The fatigue did not affect the bond strength (p=0.416), however, there was influence of the AgVO3 concentration on the bond strength between the resins (p=0.013). Mixed failures with adhesive predominance were observed in samples without AgVO3 and cohesive failures in samples with the nanomaterial. The use of AgVO3 can improve or maintain the bond strength between resins with no thermomechanical fatigue influence. (AU).

A incorporação de agentes antimicrobianos pode influenciar nas propriedades mecânicas de resinas acrílicas. Desta forma, o uso destes agentes apenas em regiões das próteses dentárias sujeitas a maior contaminação pode ser uma alternativa. Este estudo avalia o efeito da fadiga termomecânica na resistência de união entre uma resina acrílica convencional e uma experimental incorporada com vanadato de prata nanoestruturado decorado com nanopartículas de prata (AgVO3). Foram obtidos 60 espécimes (Ø13mm x 23mm de altura) em resina autopolimerizável, divididos em grupos de acordo com a resina experimental incorporada com AgVO3 (Ø4mm x 6mm de altura): G1-Convencional x Convencional, G2-Convencional x 2,5% de AgVO3, G3 -Convencional x 5% de AgVO3. Dez amostras de cada grupo foram submetidas à análise de resistência à união após a confecção e 10 foram submetidas previamente a 1.200.000 ciclos com carga de 98 N e frequência de 2Hz/segundo e banhos alternados de 5 ºC, 37 ºC e 55 ºC. A área de fratura foi analisada. Os dados foram submetidos à análise de variância de dois fatores com ajuste de Bonferroni para comparações pos hoc (α = 0,05). A fadiga não afetou a força de união (p=0,416), no entanto, houve influência da concentração de AgVO3 na resistência de união entre as resinas (p=0,013). Falhas mistas com predominância adesiva foram observadas nas amostras sem AgVO3 e falhas coesivas nas amostras contendo o nanomaterial. O uso de AgVO3 pode melhorar ou manter a resistência da união entre as resinas sem influência da fadiga termomecânica.

RESUMO

The purpose of thisin vitrostudy was to evaluate the influence of a new proposal of implant design and surgical protocol on primary stability in different bone densities. Four groups were tested (n=9): G1 - tapered, cone morse, Ø 4.3 mm x 10 mm in length (Alvim CM); G2 - experimental tapered; G3 - cylindrical, cone morse, Ø 4.0 mm x 11 mm in length (Titamax CM) and G4 - experimental cylindrical. The experimental implants were obtained from a design change in the respective commercial models. The insertion was performed in polyurethane (PU) blocks 0.24 g/cm3(20 pcf) and 0.64 g/cm3(40 pcf), according to different surgical protocols. The primary stability was measured by means of insertion torque (IT) and pullout test. Data were analyzed by ANOVA, Tukey's test (α=0.05) and Pearson's correlation. For IT and pullout, conventional and experimental implants showed no difference between them when inserted in the 20 pcf PU (p>0.05). In the 40 pcf PU, the modified implants exhibited greater IT (p<0.05) and lower pullout (p<0.05) compared to the respective conventional models. The implant design tested associated with the surgical protocol, positively influenced primary stability in higher density bones.

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RESUMO

Abstract The purpose of thisin vitrostudy was to evaluate the influence of a new proposal of implant design and surgical protocol on primary stability in different bone densities. Four groups were tested (n=9): G1 - tapered, cone morse, Ø 4.3 mm x 10 mm in length (Alvim CM); G2 - experimental tapered; G3 - cylindrical, cone morse, Ø 4.0 mm x 11 mm in length (Titamax CM) and G4 - experimental cylindrical. The experimental implants were obtained from a design change in the respective commercial models. The insertion was performed in polyurethane (PU) blocks 0.24 g/cm3(20 pcf) and 0.64 g/cm3(40 pcf), according to different surgical protocols. The primary stability was measured by means of insertion torque (IT) and pullout test. Data were analyzed by ANOVA, Tukey's test (α=0.05) and Pearson's correlation. For IT and pullout, conventional and experimental implants showed no difference between them when inserted in the 20 pcf PU (p>0.05). In the 40 pcf PU, the modified implants exhibited greater IT (p<0.05) and lower pullout (p<0.05) compared to the respective conventional models. The implant design tested associated with the surgical protocol, positively influenced primary stability in higher density bones.

Resumo O objetivo deste estudo in vitro foi avaliar a influência de uma nova proposta de design de implante e protocolo cirúrgico na estabilidade primária em diferentes densidades ósseas. Foram testados quatro grupos (n=9): G1 - cônico, cone morse, Ø 4,3 mm x 10 mm de comprimento (Alvim CM); G2 - experimental cônico; G3 - cilíndrico, cone morse, Ø 4,0 mm x 11 mm de comprimento (Titamax CM) e G4 - experimental cilíndrico. Os implantes experimentais foram obtidos a partir de uma mudança no design dos respectivos modelos comerciais. A inserção foi realizada em blocos de poliuretano (PU) 0,24 g/cm3 (20 pcf) e 0,64 g/cm3 (40 pcf), de acordo com diferentes protocolos cirúrgicos. A estabilidade primária foi aferida por meio do torque de inserção (TI) e ensaio de arrancamento. Os dados foram analisados por ANOVA, teste de Tukey (α=0,05) e correlação de Pearson. Para TI e arrancamento, os implantes convencionais e experimentais não mostraram diferença entre si quando inseridos na PU de 20 pcf (p>0,05). Na PU de 40 pcf, os implantes modificados exibiram maior TI (p <0,05) e menor arrancamento (p <0,05) em relação aos respectivos modelos convencionais. O design do implante testado associado ao protocolo cirúrgico, influenciou positivamente a estabilidade primária em ossos de maior densidade.

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ABSTRACT The aim of this case report was to describe a prosthetic rehabilitation associated with an alternative model of polymer capsule for fixation system of implant-retained overdentures. Patient sought treatment at the clinic of School of Dentistry of Ribeirão Preto, due to lack of retention of their conventional total superior prostheses and inferior overdenture. The initial complaint was clinicallyconfirmed by altered intermaxillary relationships and severe reabsorption of the maxillary crest. In order to restore the function and improve its quality of life, it was proposed a prosthetic solution including implant fixed prosthesis to maxilla and a mandibular overdenture, with ball-type attachments associated with an alternative model of polymer capsule. This treatment was proposed inorder to reestablish the intermaxillary relationships and adequate occlusion, maintain retention and stability of the prosthesis. At the end of treatment and during a one-year follow-up of the case, the patient reported satisfaction and significant improvement in quality of life.

RESUMO O objetivo deste relato de caso foi descrever uma reabilitação protética associada a um modelo alternativo de cápsula polimérica para sistema de fixação de overdentures implantado-retidas. Paciente procurou tratamento na clínica da Faculdade de Odontologia de Ribeirão Preto, devido falta de retenção de suas próteses totais superiores convencionais e overdenture inferior. A queixa inicialfoi clinicamente confirmada por relações intermaxilares alteradas e reabsorção severa da crista maxilar. Para restaurar a função e melhorar sua qualidade de vida, propôs-se como solução protética, a confecção de prótese fixa sobre implantes para a maxila e overdenture mandibular, com acessórios tipo bola associados a um modelo alternativo de cápsula polimérica. Esse tratamento foiproposto a fim de restabelecer as relações intermaxilares e a oclusão adequada, manter a retenção e a estabilidade da prótese. Ao final do tratamento e durante o acompanhamento de um ano do caso, o paciente relatou satisfação e melhora significativa na qualidade de vida.