Effect of different cleansers on the surface of removable partial denture

Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05% sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey’s test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD.As próteses parciais removíveis (PPR) exigem higienização específica e a associação da escovação com imersão em soluções químicas tem sido o método mais recomendado para controle do biofilme. Entretanto, os efeitos destas soluções não são amplamente reportados em componentes metálicos. Este estudo avaliou o efeito de diferentes agentes de higienização na superfície dos componentes de uma PPR. Foram confeccionados 5 espécimes (disco metálico de 12 x 3 mm centralizado em uma tira de resina com 38 x 18 x 4 mm) para cada situação experimental: 6 soluções [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), hipoclorito de sódio 0,05% (HS) e água destilada (AD) como controle)] e 2 ligas de cobalto-cromo [DeguDent (DD) e Vera PDI (VPDI)] foram utilizadas para cada situação experimental. Foram simuladas imersões de 180 dias. As aferições de rugosidade (Ra, μm) tanto em porção metálica quanto em resina acrílica termopolimerizável foram submetidos ao ANOVA e ao teste de Tukey. As alterações superficiais e manchas foram examinadas por meio de microscopia eletrônica de varredura (MEV). Áreas de interesse foram submetidas à espectrometria por energia dispersiva por raios X (EDS). Visualmente, puderam ser verificadas manchas nas superfícies metálicas quando utilizados HS e MI. A rugosidade dos materiais não foi afetada pelas soluções (p>0,05). As fotomicrografias evidenciaram que HS e MI ocasionaram alterações superficiais. As análises de EDS revelaram a presença de oxigênio nos grupos HS e MI, o que pode sugerir que estas duas soluções causaram oxidação das superfícies, provocando pontos de corrosão. Dentre as limitações do presente estudo, pode-se concluir que estas soluções não são apropriadas para a higienização das PPR

Comparison of physical and mechanical properties of microwave-polymerized acrylic resin after disinfection in sodium hypochlorite solutions

This study evaluated the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin after immersion in sodium hypochlorite (NaOCl), simulating 20 min of disinfection daily during 180 days. Forty disk-shaped (15 x 4 mm) and 40 rectangular (65 x 10 x 3 mm) specimens were prepared with a microwave-polymerized acrylic resin (Onda-Cryl). Specimens were immersed in either 0.5% NaOCl, 1% NaOCl, Clorox/Calgon and distilled water (control). Color measurements were determined by a portable colorimeter. Three parallel lines, separated by 1.0 mm, were registered on each specimen before and after immersion procedures to analyze the surface roughness. The flexural strength was measured using a 3-point bending test in a universal testing machine with a 50 kgf load cell and a crosshead speed of 1 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (?=0.05). There was no statistically significant differences (p>0.05) among the solutions for color, surface roughness and flexural strength. It may be concluded that immersion in NaOCl solutions simulating short-term daily use during 180 days did not influence the color stability, surface roughness and flexural strength of a microwave-polymerized acrylic resin.Este estudo avaliou a estabilidade de cor, rugosidade superficial e resistência à flexão de resina acrílica polimerizada por microondas após desinfecção em hipoclorito de sódio, simulando 20 min de desinfecção diária durante 180 dias. Quarenta espécimes circulares (15 x 4 mm) e 40 retangulares (65 x 10 x 3 mm) foram preparados em resina acrílica polimerizada por microondas (Onda-Cryl). As amostras foram imersas em hipoclorito de sódio a 0,5%, hipoclorito de sódio a 1%, Clorox/Calgon e água destilada (controle). Medidas de cor foram determinadas por um espectrocolorímetro portátil. Três linhas paralelas, separadas por 1,0 mm, foram registradas em cada amostra antes e depois dos procedimentos de imersão para analisar a rugosidade superficial. A resistência à flexão foi medida utilizando um teste de flexão por 3 pontos em uma máquina universal de ensaios com uma célula de carga de 50 Kgf e uma velocidade de 1 mm/min. Os dados foram analisados estatisticamente por ANOVA e teste de Tukey (?=0,05). Não houve diferença estatisticamente significante (p>0,05) entre as soluções para cor, rugosidade superficial e resistência à flexão. Pode-se concluir que a imersão em soluções de hipoclorito de sódio, simulando um uso diário de curta duração durante 180 dias, não influenciou a estabilidade de cor, rugosidade superficial e resistência à flexão de resina acrílica polimerizada por microondas.FAPESPCNP

Oral health-related quality of life of athletes with disabilities: a cross sectional study

Several studies have suggested that athletes with disabilities experience more difficulties having access to oral health care than the population in general. The aim of this study was to estimate the impact of socio-demographic/socio-economic factors, oral hygiene habits and clinical oral health conditions on the OHRQoL – Oral Health-Related Quality of Life (assessed with the Oral Health Impact Profile 14 – OHIP-14) on a sample of athletes with heterogeneous types of disabilities. Altogether, 105 athletes with disabilities were evaluated. Cross-sectional data was collected including interviews to obtain socio-demographic/socio-economic data, the OHIP-14 and clinical oral examinations parameters. The outcome variable was the OHIP-14 severity score. The explanatory variables were sex, age, monthly household income, level of schooling, frequency of toothbrushing and flossing, gingival bleeding, periodontal disease, trauma in incisors, prosthesis wearing and needs, number of sound teeth, DFMT (decayed, filled and missing teeth) index and its isolate components. Mann-Whitney, Kruskall-Wallis and Spearman tests used to compare OHIP-14 severity scores associated with the explanatory variables. The mean OHIP-14 severity score for the sample was 9.32 (SD 8.99) and the most affected domain was Physical Pain (mean 2.63; SD 1.97), followed by Psychological Discomfort (mean 1.81; SD 2.02). Significant differences in mean OHIP-14 scores were found for periodontal disease, need for complete dentures, number of sound teeth, DFMT index and its components. These results suggest that these clinical parameters can be related to impaired OHRQoL for this population

Color, corrosion and surface roughness evaluation of titanium c.p., alloys and heat-polymerized acrylic resin under the action of daily hygiene solutions

A higienização das próteses parciais ou totais removíveis é fundamental para a durabilidade do tratamento e prevenção de patologias orais. O objetivo deste estudo foi avaliar o efeito de agentes higienizadores de prótese na cor, corrosão e rugosidade superficial do titânio c.p., ligas metálicas e resina acrílica termopolimerizável, simulando um período de 180 dias de higienização. Espécimes em formato de discos (12 mm x 3 mm) foram confeccionados em: titânio comercialmente puro (Tritan - Ti c.p.), liga de níquel-cromo-molibdênio-titânio (Vi-Star), liga de níquel-cromo (Fit Cast-SB Plus) e liga de níquel-cromo-berílio (Fit Cast-V). Cada disco fundido foi incluído em mufla previamente preparada por matrizes retangulares de teflon (38 mm x 18 mm x 4 mm), incorporando-se o disco metálico à resina acrílica termopolimerizável. Os corpos-de-prova (n=5) foram imersos em soluções dos agentes higienizadores: hipoclorito de sódio a 0,05%, Periogard, Cepacol, pastilha Corega Tabs, pastilha Medical Interporous e pastilha Polident 3 Minute. Como controle, foi utilizada a água deionizada. Foram realizados ensaios de estabilidade de cor por meio de espectrocolorímetro (Color-guide 45/0), resistência à corrosão por meio da análise visual da presença de manchas no metal e análise da alteração de massa (balança eletrônica analítica), e rugosidade superficial por meio de rugosímetro (Surftest SJ-201P). Além disso, foi realizada análise quantitativa de liberação de íons metálicos por meio de espectrometria de massa com plasma indutivamente acoplado (ICP-MS - ELAN DRC II). Os resultados de estabilidade de cor, alteração de massa e rugosidade foram submetidos à ANOVA e teste de Tukey (p< 0,05). Quanto à estabilidade de cor da resina acrílica termopolimerizável (E), houve diferença estatisticamente significante entre o titânio c.p. e as ligas. A resina associada ao Ti c.p. apresentou menor alteração de cor, enquanto que a resina associada à Fit Cast-SB Plus apresentou a maior alteração de cor (1,33 ± 1,11 e 5,06 ± 1,96, respectivamente). Com relação à presença de manchas no metal, o hipoclorito de sódio causou manchamento nos espécimes das ligas Vi-Star e Fit Cast-V. Quando avaliada a alteração de massa (g), o Cepacol e a pastilha Corega Tabs propiciaram maior perda de massa. Entre os metais, a amostra do Ti c.p. apresentou maior perda de massa. Quanto à rugosidade (Ra, µm) da resina, o Cepacol causou maior rugosidade, enquanto que a pastilha Corega Tabs e o Periogard propiciaram maior lisura no corpo-de-prova. A resina associada ao Ti c.p. e ao Fit Cast-SB Plus apresentaram maior rugosidade. Quanto à rugosidade do metal, os produtos de imersão não influenciaram nos resultados, mas a liga Fit Cast-SB Plus apresentou maior rugosidade após a imersão. A liberação de íons mais expressiva foi constatada nas ligas Vi-Star e Fit Cast-V após a imersão na pastilha Medical Interporous. Pode-se concluir que as ligas Vi-Star e Fit Cast-V podem ser consideradas seguras para a confecção de aparelhos protéticos removíveis, mas com a condição de não utilizar o hipoclorito de sódio a 0,05% ou a pastilha Medical Interporous para a higienização, pois causaram corrosão e maior liberação de íons, respectivamente.The hygiene care of the removable partial and complete dentures is required for the longevity of the treatment and prevention of oral diseases. The aim of this study was to evaluate the effect of denture cleansers on color, corrosion and surface roughness of the commercially pure titanium, metal alloys and heat-polymerized acrylic resin, simulating a period of 180 days of hygiene. Disk-shaped specimens (12 mm x 3 mm) had been fabricated with commercially pure titanium (Tritan - Ti c.p.), nickel-chromium-molybdenum-titanium alloy (Vi-Star), nickel-chromium alloy (Fit Cast-SB Plus) and nickel-chromium-beryllium alloy (Fit Cast-V). Each cast disc was invested in the flasks previously prepared by Teflon rectangular matrices (38 mm x 18 mm x 4 mm), incorporating the metal disk to the heat-polymerized acrylic resin. The specimens (n= 5) had been immersed in the solutions: sodium hypochlorite 0.05%, Periogard, Cepacol, Corega Tabs, Medical Interporous and Polident 3 Minute. As a control, it was used deionized water. It was accomplished assays of color stability by means of a colorimeter (Color-guide 45/0), corrosion resistance by means of visual analysis of tarnishes on the metal and mass alteration analysis (analytical electronic balance), and surface roughness by means of a surface analyzer (Surftest SJ-201P). Besides, the quantitative analysis of metal ions release was accomplished by means of inductively coupled plasma mass spectrometry (ICP-MS - ELAN DRC II). Color stability, mass alteration and roughness results were submitted to ANOVA and Tukey test (p<0.05). Considering the color stability of the heat-polymerized acrylic resin (E), there were statistically significant difference between the titanium c.p. and the alloys. The resin associated with the Ti c.p. showed lesser color alteration, whereas the resin associated with Fit Cast-SB Plus showed the higher color alteration (1,33 ± 1,11 e 5,06 ± 1,96, respectively). In relation to the presence of tarnishes on the metals, the sodium hypochlorite caused tarnishes on specimens of the Vi-Star and Fit Cast-V alloys. When evaluated the mass alteration (g), Cepacol and Corega Tabs propitiated higher weight loss. Between the metals, the Ti c.p. samples showed greater weight loss. Considering the resin roughness (Ra, µm), Cepacol caused higher roughness, whereas Corega Tabs and Periogard propitiated greater smoothness on the specimens. The resin associated with the Ti c.p. and Fit Cast-SB Plus showed higher roughness. Considering the metal roughness, the immersion products did not influence on the results, but the Fit Cast-SB Plus showed greater roughness after immersion. The ionic release most significant was with the Vi-Star and Fit Cast-V alloys after immersion in Medical Interporous. It could be concluded that the Vi-Star and Fit Cast-V alloys can be considered safe for removable prosthesis finish, but with the condition of do not use sodium hypochlorite 0.05% or Medical Interporous tablet for hygiene, because they caused corrosion and greater ionic release, respectively

Liberdade rotacional em implantes dentários avaliada pelos métodos experimental e analítico

The aim of this study was to evaluate the integrity of the external hexagon of Internal Torque implants (IT Neodent Implante Osteointegrável), that despite of the external hexagon it uses internal hexagon to receive torque during surgical placement, comparing with external hexagon implants: conventional (External Hexagon, EH - Neodent Implante Osteointegrável) and Brånemark System MK III (Nobel Biocare, NO). Moreover, it was validated an analytical model of rotational freedom with experimental measurements. A device was made to measure rotational freedom angles between hexagons of implant and abutment for 10 intact samples of each group and after simulating surgical placement under torques of 45, 60 and 80 Ncm. The distance between the sides of the abutments internal hexagon had been measured for, together with the values of experimental rotational freedom, using the analytical model, with the aid of the program MATLAB. By means of this model it was possible to get the distances between the sides of the external hexagon of implants and thus to guide the measures in mono ocular optical microscope. Also, the distance between vertexes of the external hexagon were obtained for all intact samples. Again, the analytical model was used to get theoretical rotational freedom, in order to validate it. This sequence was repeated after each torque applied. Rotational freedom data were subjected to analysis of variance test (P<.05) showing no significant difference for the angles of intact EH and IT implants: EH 3.31±0.41° and IT 3.30±0.17°; and after 45 Ncm torque: EH 3.27±0.38° and IT 3.31±0.22°. Both were different from intact NO implants: 2.58±0.35°; and after 45 Ncm torque: 2.62±0.35°, that presented the lesser values. However, after 60 Ncm torque there were significant difference between the three types of implants: NO 2.67±0.34°, IT 3.40±0.20° and EH 4.03±0.54°. After 80 Ncm torque, there were significant difference between NO and IT implants, and the averages were 2.63±0.34° and 3.39±0.38°, respectively. The EH implants did not support this torque, deforming the external hexagon. The data of the distances between vertexes of the external hexagon were subjected to Mann-Whitney U test (P<.05) showing no significant difference for intact EH and IT implants, but both were different from NO implants, that presented the lesser values. After the torque of 60 Ncm, EH, IT and NO implants had presented equal statistical results. After the torque of 80 Ncm, IT and NO implants had not presented significant difference, but when comparing to EH implants both had presented difference, with EH implants presenting the lesser values. It could be concluded that IT and NO implants reacted better than EH implant after 60 and 80 Ncm torques in relation to the rotational freedom values. And still, the analytical model used in program MATLAB is valid to determine the theoretical rotational freedom angle of each sample after different levels of torque applied, without the need to realize measurements of rotational freedom in experimental device, being enough to get the distances between the sides of the hexagons of abutment and implants.Mestre em OdontologiaO objetivo deste estudo foi avaliar a integridade do hexágono externo de implantes Torque Interno (TI Neodent Implante Osteointegrável), que apesar do hexágono externo utiliza hexágono interno para receber torque durante a inserção cirúrgica, comparando com implantes também hexágono externo: convencional (Hexágono Externo, HE Neodent Implante Osteointegrável) e Brånemark System MK III (Nobel Biocare, NO). Além disto, foi validado um modelo analítico da liberdade rotacional com medidas experimentais. Um dispositivo foi fabricado para medir os ângulos de liberdade rotacional entre hexágonos de implante e pilar para 10 amostras intactas de cada grupo e após simulação de inserção cirúrgica sob torques de 45, 60 e 80 Ncm. Foram medidas as distâncias entre os lados do hexágono interno dos pilares para, juntamente com os valores de liberdade rotacional experimental, utilizar o modelo analítico, com auxílio do programa MATLAB. Por meio deste modelo foi possível obter as distâncias entre os lados do hexágono externo dos implantes e assim orientar as medidas em microscópio óptico mono ocular. Também, as distâncias entre os vértices do hexágono externo dos implantes foram obtidas para todas amostras intactas. Novamente, utilizou-se o modelo analítico para obter a liberdade rotacional teórica, a fim de validá-lo. Esta seqüência foi repetida após cada torque aplicado. Os dados de liberdade rotacional foram submetidos ao teste de análise de variância (p<0,05) demonstrando não haver diferença significante para os ângulos dos implantes HE e TI intactos: HE 3,31±0,41° e TI 3,30±0,17°; e após o torque de 45 Ncm: HE 3,27±0,38° e TI 3,31±0,22°. Ambos foram diferentes dos implantes NO intactos: 2,58±0,35° e após o torque de 45 Ncm: 2,62±0,35°, que apresentaram os menores valores. No entanto, após o torque de 60 Ncm, houve diferença significante entre os três tipos de implantes: NO 2,67±0,34°, TI 3,40±0,20° e HE 4,03±0,54°. Após o torque de 80 Ncm, houve diferença significante entre os implantes NO e TI, e as médias foram 2,63±0,34° e 3,39±0,38°, respectivamente. O implante HE não suportou este torque, deformando o hexágono externo. Os dados das distâncias entre os vértices dos hexágonos externos dos implantes foram submetidos ao teste U de Mann-Whitney (p<0,05) demonstrando não haver diferenças significantes para os implantes HE e TI intactos, mas ambos foram diferentes dos implantes NO, que apresentaram os menores valores. Após o torque de 60 Ncm, os implantes HE, TI e NO apresentaram resultados iguais estatisticamente. Após o torque de 80 Ncm, os implantes TI e NO não apresentaram diferença significante mas quando comparados aos implantes HE ambos apresentaram diferença, com os implantes HE apresentando os menores valores. Pode-se concluir que os implantes TI e NO comportaram melhor que o implante HE após a aplicação dos torques de 60 e 80 Ncm com relação aos valores de liberdade rotacional. E ainda, o modelo analítico utilizado no programa MATLAB é válido para determinar o ângulo de liberdade rotacional teórico de cada amostra após a aplicação dos diferentes níveis de torque, sem a necessidade de realizar as medidas de liberdade rotacional em dispositivo experimental, sendo suficiente se obter as distâncias entre os lados dos hexágonos do pilar e dos implantes

Immediate loading implants with mandibular overdenture: a 48-month prospective follow-up study

The aim of this prospective clinical study was to evaluate patient rehabilitation with two immediately loaded implants and bar-retained mandibular overdentures after 48 months of follow-up. Twenty patients were treated with two implants each; of these, 17 patients were re-evaluated for comparison. Gender, age, plaque index, gingival inflammation, keratinized mucosa, probing depth, bleeding, and implant loss data were recorded, and periapical radiographs were obtained for measurement of marginal bone loss. The results were statistically analyzed with one-way analysis of variance (ANOVA) followed by Student&#8217;s t-test and Pearson&#8217;s correlation test. To compare the data at baseline and after 48 months, a Wilcoxon Signed Rank Test was performed (&#945; = 0.05). One implant failed (2.9%) during the first year and was replaced. A total of 35 implants were evaluated. Bone loss values were 0.52&#8211;2.89 mm (mean, 1.46 mm). Probing depth was 1.75&#8211;3.75 mm (mean, 2.22 mm). Correlations were found between bone loss and plaque index and between bone loss and gender, but bone loss did not correlate with gingival inflammation, keratinized mucosa, probing depth, or age. The overall survival rate of the implants was 97.1%. Based on these results, the use of two immediately loaded splinted interforaminal implants to retain an overdenture with a bar attachment is a clinically viable option with a high survival rate

In vitro integrity of implant external hexagon after application of surgical placement torque simulating implant locking

The aim of this study was to evaluate the integrity of the external hexagon of an implant system with internal and external hexagons but with prosthetic connection through the external hexagon (Internal Torque, IT) in comparison with that of an implant system with external hexagon with mount (External Hexagon, EH). A device was made to measure the rotational freedom angles between implant and abutment hexagons in 10 implants from each group after the application of surgical placement torques of 45, 60 and 80 Ncm simulating implant locking. The distances between the vertices of the external hexagon were also obtained. Rotational freedom data were subjected to ANOVA and Tukey's test (P < .05) showing no significant difference between the angles of the intact implants (EH - 3.31 ± 0.41° and IT - 3.30 ± 0.17°) and after application of a 45 Ncm torque (EH - 3.27 ± 0.38° and IT - 3.31 ± 0.22°). However, after application of a 60 Ncm torque there were significant differences (IT - 3.40 ± 0.20° and EH - 4.03 ± 0.54°). After application of a 80 Ncm torque, the IT implant presented values of 3.39 ± 0.21° whereas the EH did not support the torque, suffering deformation of its external hexagon. Within the limits of this study, it can be concluded that the IT implant system may be preferable in clinical situations where implant placement within a certain bone density could generate torques higher than 60 Ncm