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1.
Dent Med Probl ; 57(3): 239-246, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33074597

RESUMO

BACKGROUND: The incorporation of an antibacterial agent into an adhesive could improve its clinical performance. Some nanoparticles (NPs), including copper nanoparticles (Cu NPs), display an antibacterial effect. Therefore, Cu NPs could act as a nanofiller when added to an adhesive. OBJECTIVES: The aim of this study was to evaluate the antibacterial activity, cytotoxicity and shear bond strength (SBS) of an experimental dental adhesive with Cu NPs. MATERIAL AND METHODS: Different concentrations (0.0050 wt%, 0.0075 wt% and 0.0100 wt%) of Cu NPs were added to the adhesive. The distribution of Cu NPs in the polymer matrix was observed based on transmission electron microscope (TEM) images. The antimicrobial activity of the adhesive + Cu NPs was evaluated with the agar disk diffusion test against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Streptococcus mutans (S. mutans). The cytotoxicity assay was performed by means of the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method with human pulp cells (HPC). Additionally, the SBS tests were carried out (n = 31) and the modes of fracture were registered. The vestibular and lingual surfaces of each tooth were randomly assigned to the study groups (group I - control adhesive; group II - adhesive + 0.0100 wt% Cu NPs). The samples were statistically analyzed (p ≤ 0.05). RESULTS: The adhesive + 0.0100 wt% Cu NPs showed inhibition zones against the strains under study that were similar to, or slightly smaller than, the halos produced by chlorhexidine (CHX) and specific drugs for each strain (30 µg of cefotaxime against S. mutans and S. aureus, and 1.25/3.75 µg of sulfamethoxazole/ trimethoprim against E. coli). The control adhesive was moderately cytotoxic (relative cell viability of 36.7 ±0.8%), being more cytotoxic than Cu NPs themselves (58.3 ±0.1%). A significantly higher SBS was obtained for the adhesive + 0.0100 wt% Cu NPs (6.038 ±2.95 MPa) than for the control group (3.278 ±1.75 MPa). The modes of fracture in group I were almost equally distributed between adhesive and cohesive failures whereas in group II, the failure was mainly cohesive. CONCLUSIONS: The results of this study suggest that incorporating Cu NPs into an adhesive improves its SBS and provides it with antibacterial properties, without increasing its inherent cytotoxicity - 2 desirable characteristics for the dental adhesives of composites.

2.
Prog Orthod ; 21(1): 24, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32803386

RESUMO

BACKGROUND: The purpose of the study is to assess the antiadherent and antibacterial properties of surface-modified different orthodontic brackets with silver nanoparticles against Streptococcus mutans and Streptococcus sobrinus, using radiomarker. METHODS: In this study evaluated quantitatively the adherence of Streptococci to orthodontic brackets, 300 samples of orthodontic brackets were selected and classified in to 10 groups as follow: GIn (InVu-Roth), GIIn (System-AlexanderLTS), GIIIn (Gemini-Roth), GIVn (NuEdge-Roth), GVn (Radiance plus-Roth), GVI (InVu-Roth), GVII (System-AlexanderLTS), GVIII (Gemini-Roth), GIX (NuEdge-Roth), GX (Radiance plus-Roth). All the samples were sonicated and Streptococci were cultivated by gender. A radioactive marker (3H) was used to codify the bacteria and measure them. After that, the brackets were submerged in a radiolabelled solution, and the radiation was measured. The statistical analysis was calculated with ANOVA test (Sheffè post hoc). RESULTS: The results showed significant differences were found among the groups. GIIIn shown the lowest scores for both bacteria; in contrast, GIX for Streptococcus mutans and GVI for Streptococcus sobrinus were the highest values. CONCLUSIONS: Surface modification of orthodontic brackets with silver nanoparticles can be used to prevent the accumulation of dental plaque and the development of dental caries during orthodontic treatment.


Assuntos
Cárie Dentária , Nanopartículas Metálicas , Braquetes Ortodônticos , Ortodontia , Humanos , Prata , Streptococcus mutans , Streptococcus sobrinus
3.
J Am Dent Assoc ; 151(4): 276-286, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32222176

RESUMO

BACKGROUND: The objective of this study was to compare the experience and distribution of tooth loss in people with and without diabetes. METHODS: The authors conducted a comparative cross-sectional study of patients at a public university. Analysis included medical records of those treated from 2013 through 2017. The dependent and main independent variables were the number of missing teeth and a diagnosis of diabetes, respectively. As covariables, the authors analyzed the sociodemographic and socioeconomic characteristics, as well as the general and oral health status of patients. A multivariate model based on negative binomial regression was constructed. RESULTS: Of the 3,406 medical records analyzed, 64.2% (n = 2,185) pertained to women, the mean age was 42.45 years, 87.9% did not have diabetes, and 12.1% had received a diagnosis of diabetes. The mean (standard deviation) number of missing teeth was 7.46 (7.89), 7.09 (7.60) in patients without diabetes, and 10.12 (9.32) in patients with diabetes. According to our final multivariate model, the expected mean number of missing teeth was 11.4% higher in patients with diabetes than in those without (P = .006). For every 1-year increase in age, the expected mean number of missing teeth increased by 3.9% (P < .001). Other variables related to tooth loss included occupation, marital status, and type of insurance. CONCLUSIONS: The results of the study indicate that the mean number of missing teeth is higher in people with diabetes and suggest that certain socioeconomic inequalities exist in the area of oral health. PRACTICAL IMPLICATIONS: The population needs to be apprised of the impact of diabetes on oral health.


Assuntos
Diabetes Mellitus , Perda de Dente , Adulto , Estudos Transversais , Feminino , Humanos , México , Saúde Bucal
4.
Oral Health Prev Dent ; 18(1): 35-42, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32051969

RESUMO

PURPOSE: To determine any associations between obesity and caries activity in the mixed dentition stage among primary school children in a low-income Mexican primary school. MATERIALS AND METHODS: This cross-sectional study was performed in Mexican schoolchildren aged 8-12 years. The body mass index (BMI) was obtained, and children were classified as overweight/obese considering age and sex. The experience of caries in permanent and temporary dentition was established with the sum of decayed/missing/filled teeth (DMFT or deft index for permanent or temporal dentition); a caries index for all teeth was also considered (total decay [TD]). Mann-Whitney U-test was used to contrast the distribution between sexes of the quantitative variables and to contrast the distribution of each variable per category, the Kruskal-Wallis test was used. Spearman's Rho test was used to establish the correlation between the quantitative variables. Multiple linear regression models were performed to find the relationship between the O'Leary index and the BMI. A Multilayer Perceptron was constructed as follows: (a) dependent variables: deft, DMFT, TD and O'Leary index; (b) factor: BMI; (c) covariable: age. RESULTS: A total of 331 children were included in the study. Dental caries prevalence was 32.4% (95% CI 29.7-35.2), while the mean DMFT was 0.64 (± SD 1.00). Through the Spearmen test, a statistically significant negative correlation was found between BMI-for-age with the total experience of carious lesions (r = -0.127, p = 0.021) and with experience of carious lesions in the deciduous dentition (deft) (r = -0.195, p ≤0.001). But when using the linear and logistic regression models to analyse the relationship with the O'Leary index, BMI was not statistically significant. With the Multilayer Perceptron there appears to be less error in the prediction of deft than the other indexes. CONCLUSIONS: This study confirms the high prevalence of obesity in primary school children. It also shows the scarce association between carious lesions and obesity.


Assuntos
Cárie Dentária , Criança , Estudos Transversais , Índice CPO , Humanos , México , Obesidade , Prevalência
5.
Microsc Res Tech ; 82(11): 1869-1877, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31373738

RESUMO

Laser irradiation has been proposed as a preventive method against dental caries since it is capable to inhibit enamel demineralization by reducing carbonate and modifying organic matter, yet it can produce significant morphological changes. The purpose of this study was to evaluate the influence of Er:YAG laser irradiation on superficial roughness of deciduous dental enamel and bacterial adhesion. Fifty-four samples of deciduous enamel were divided into three groups (n = 18 each). G1_control (nonirradiated); G2_100 (7.5 J/cm2 ) and G3_100 (12.7 J/cm2 ) were irradiated with Er:YAG laser at 7.5 and 12.7 J/cm2 , respectively, under water irrigation. Surface roughness was measured before and after irradiation using a profilometer. Afterwards, six samples per group were used to measure bacterial growth by XTT cell viability assay. Adhered bacteria were observed using confocal laser scanning microscopy (CLSM) and a scanning electron microscopy (SEM). Paired t-, one-way analysis of variance (ANOVA), Kruskal-Wallis and pairwise Mann-Whitney U tests were performed to analyze statistical differences (p < .05). Before treatment, samples showed homogenous surface roughness, and after Er:YAG laser irradiation, the surfaces showed a significant increase in roughness values (p < .05). G3_100 (12.7 J/cm2 ) showed the highest amount of Streptococcus mutans adhered (p < .05). The increase in the roughness of the tooth enamel surfaces was proportional to the energy density used; the increase in surface roughness caused by laser irradiation did not augment the adhesion of Streptococcus sanguinis; only the use of the energy density of 12.7 J/cm2 favored significantly the adhesion of S. mutans.


Assuntos
Aderência Bacteriana/efeitos da radiação , Cárie Dentária/prevenção & controle , Esmalte Dentário/efeitos da radiação , Lasers de Estado Sólido/uso terapêutico , Streptococcus mutans/fisiologia , Streptococcus/fisiologia , Aderência Bacteriana/fisiologia , Humanos , Microscopia Eletrônica de Varredura , Streptococcus/crescimento & desenvolvimento , Streptococcus/efeitos da radiação , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/efeitos da radiação , Streptococcus sanguis , Propriedades de Superfície/efeitos da radiação
6.
Medicine (Baltimore) ; 98(30): e16634, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31348316

RESUMO

INTRODUCTION: Dental caries is the most frequent oral disease worldwide and the main cause of tooth loss in children and young adults. One of the most frequently affected areas is the occlusal surfaces of the first permanent molars (FPM) due to their morphological complexity. At present, several preventive treatments can reduce the incidence of this disease in school populations. In Mexico, the most commonly used technologies are those derived from some presentation of fluoride; on the other hand, research on this topic has been limited. OBJECTIVE: To determine the cost-effectiveness of two different methods for preventing the incidence of caries on the FPM of schoolchildren (6-8 years of age) from public primary schools. MATERIAL AND METHODS: This is a randomized experimental design. Participants will be assigned to two treatment groups of 114 each. In the first group, pit and fissure sealants will be applied, whereas the second group will receive a fluoride varnish. The work will be carried out in schoolchildren that attend public elementary schools in the state of Hidalgo, Mexico. The result variable will be the incidence of caries and the total cost of each of the interventions will be calculated in order to calculate the intervention's cost-effectiveness. CONCLUSION: This work will allow us to compare the cost-effectiveness of the pit and fissure sealants and the fluoride varnish in order to determine which offers the best results.


Assuntos
Cárie Dentária/prevenção & controle , Fluoretos Tópicos/uso terapêutico , Selantes de Fossas e Fissuras/uso terapêutico , Criança , Análise Custo-Benefício , Método Duplo-Cego , Feminino , Fluoretos Tópicos/administração & dosagem , Fluoretos Tópicos/economia , Humanos , Masculino , México , Selantes de Fossas e Fissuras/economia , Projetos de Pesquisa
7.
Medicine (Baltimore) ; 98(11): e14875, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30882692

RESUMO

Dental caries-a highly prevalent public health problem in preschoolers and school children-is the main cause of premature dental loss during childhood, and this may be related to loss of space in the posterior sector. The objective of this study was to evaluate whether interproximal caries and premature tooth loss (D and/or E) are risk factors for loss of space in the posterior sector.A comparative cross-sectional study (split-mouth type) was performed in schoolchildren (6-8 years old). Seventeen gypsum models were evaluated. These children presented with unilateral loss of a dental organ or interproximal caries (teeth D and/or E) and without such affectations on the other side. Measurements were made with a digital Vernier caliper. The dependent variable was the difference (loss of space, mm) between the control and case sides. The independent variables were type of affectation (interproximal caries or tooth loss), sex, age, arcade, and number of interproximal surfaces affected.The mean age was 6.82 ±â€Š0.44 years and 64.7% were boys. The average space loss was 1.09 ±â€Š0.18 mm (control vs case; P < .0001). A greater loss of space was observed among those who lost a dental organ than those with interproximal caries (P = .0119). A correlation was observed between the variable loss of space and the number of interproximal surfaces affected (r = 0.5712, P = .0166).Interproximal caries and tooth loss were risk factors for loss of space in the posterior segment in this sample of Mexican schoolchildren.


Assuntos
Cárie Dentária/complicações , Criança , Estudos Transversais , Cárie Dentária/diagnóstico , Cárie Dentária/epidemiologia , Feminino , Humanos , Masculino , México , Prevalência , Fatores de Risco , Perda de Dente/classificação , Perda de Dente/complicações , Dente Decíduo/fisiopatologia
8.
Medicine (Baltimore) ; 97(22): e10887, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29851810

RESUMO

The objective of this study was to compare the differences between the measurements performed manually to those obtained using a digital model scanner of patients with orthodontic treatment.A cross-sectional study was performed in a sample of 30 study models from patients with permanent dentition who attended a university clinic between January 2010 and December 2015. For the digital measurement, a Maestro 3D Ortho Studio scanner (Italy) was used and Mitutoyo electronic Vernier calipers (Kawasaki, Japan) were used for manual measurement. The outcome variables were the measurements for maxillary intercanine width, mandibular intercanine width, maxillary intermolar width, mandibular intermolar width, overjet, overbite, maxillary arch perimeter, mandibular arch perimeter, and palate height. The independent variables, besides age and sex, were a series of arc characteristics. The Student t test, paired Student t test, and Pearson correlation in SPSS version 19 were used for the analysis.Of the models, 60% were from women. Two of nine measurements for pre-treatment and 6 of 9 measurements for post-treatment showed a difference. The variables that were different between the manual and digital measurements in the pre-treatment were maxillary intermolar width and palate height (P < .05). Post-treatment, differences were found in mandibular intercanine width, palate height, overjet, overbite, and maxillary and mandibular arch perimeter (P < .05).The models measured manually and digitally showed certain similarities for both vertical and transverse measurements. There are many advantages offered to the orthodontist, such as easy storage; savings in time and space; facilitating the reproducibility of information; and conferring the security of not deteriorating over time. Its main disadvantage is the cost.


Assuntos
Pesos e Medidas Corporais/métodos , Arco Dental/anatomia & histologia , Odontometria/métodos , Ortodontia/métodos , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Mandíbula/anatomia & histologia , Maxila/anatomia & histologia , México , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Adulto Jovem
9.
Microsc Res Tech ; 81(5): 494-501, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29411473

RESUMO

The morphological and chemical changes in deciduous dentin produced by different conditioning protocols were evaluated in this in vitro study. Eighty primary dentin samples were divided into eight groups (n = 10): G1, acid etching; G2, self-etching adhesive; G3, G4, Er: YAG laser irradiation at 25.5 and 38.2 J cm-2 , respectively; 10 Hz and spray irrigation. Groups 5, 6, 7, and 8 were irradiated at previous densities, and then phosphoric acid or self-etching adhesive conditioning was applied. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to evaluate chemical and morphological changes. Paired t-test and One-way ANOVA were used for statistical analysis (p ≤ 0.05). All samples showed different morphology with specific characteristics according to the conditioning protocol. Changing element concentration values are expressed in atomic percent (at %). After conditioning, there were statistically significant differences (p ≤ 0.05) for p at% and Ca/P in all groups; highlighting the following additional findings by group: G1, G7, and G8 showed changes in all elements studied, G2 presented a decrease in C at% and increased Ca at%, G3 and G4 exhibited at% changes in C, trace elements and Ca. Furthermore, G5 showed at% changes in O and trace elements; while G6 changes were observed on C at%, O at% and trace elements at%. Dentin morphology and chemical composition varied in accordance with the conditioning protocol, with characteristics specific for each one that could have clinical implications for the retention and bond strength performance of adhesive materials.


Assuntos
Dentina/citologia , Dentina/efeitos dos fármacos , Ácidos Fosfóricos/farmacologia , Análise de Variância , Dentina/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Espectrometria por Raios X , Oligoelementos/química
10.
Artigo em Inglês | MEDLINE | ID: mdl-28800094

RESUMO

OBJECTIVE: To determine the frequency and associated factors of visits to the dentist in the last year by Nicaraguan schoolchildren to receive professionally applied topical fluoride (PATF). MATERIAL AND METHODS: A cross-sectional study was designed in children from public schools in the city of León, Nicaragua, were included. A series of socioeconomic, sociodemographic, and behavioural variables were collected through a questionnaire. The dependent variable was the visit to the dentist to receive professionally applied topical fluoride in the last year, which was dichotomised as (0) Did not receive PATF and (1) Yes received PATF. In the statistical analysis, binary logistic regression was used. RESULTS: The mean age of the students included was 9 years, and 49.9% were girls. The prevalence of visits to the dentist in the last year to receive PATF was 3.1%. In the multivariate model, the associated characteristics (p < 0.05) were: female (OR = 2.73, 95% CI = 1.34-4.50); the positive attitude of the mother to the oral health of her child (OR = 2.15, 95% CI = 1.03-4.50); and the best socioeconomic position (OR = 2.68, 95% CI = 1.36-5.31). CONCLUSIONS: The prevalence of visits to the dentist in the last year to receive professionally applied topical fluoride was very low (3.1%). The results of the socioeconomic position suggest the existence of certain inequalities in oral health. It is necessary to implement policies and programs aimed at improving this scenario.


Assuntos
Países em Desenvolvimento , Fluoretos Tópicos , Fatores Socioeconômicos , Criança , Estudos Transversais , Assistência Odontológica , Feminino , Humanos , Modelos Logísticos , Masculino , Nicarágua , Instituições Acadêmicas , Estudantes , Inquéritos e Questionários
11.
Sci Rep ; 6: 36383, 2016 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-27805027

RESUMO

Dental demineralization was determined in patients at three time points during fixed orthodontic treatment. A multiple cross-sectional study included 108 patients divided into three different groups: (1) beginning of orthodontic treatment; (2) one year into treatment; and (3) two years into treatment. Demineralization was estimated using a DIAGNOdent pen. We obtained data from multiple tooth-by-tooth demineralization readings combined with salivary pH and patients' oral hygienic and dietary behaviors. A t-test for independent samples and Spearman´s correlation were performed. No demineralizations differences were found between the initial stage and one year into treatment. Between one and two years small differences were observed, but demineralization increased between the initial stage and second treatment year, predominating in upper right central incisors (p = 0.056), upper left lateral incisors (p = 0.040), both upper canines (p = 0.055 and p = 0.040, respectively) and first left premolars (p = 0.034 and p = 0.053, respectively). We did not find associations between oral hygiene and dietary behaviours or salivary pH. In conclusion, demineralization occurred in first year of treatment and increased during second year, predominating in the upper arch and the left side mainly in upper right central incisors, upper left lateral incisors, both upper canines, and first left premolars.


Assuntos
Braquetes Ortodônticos/efeitos adversos , Desmineralização do Dente/diagnóstico , Adolescente , Estudos Transversais , Dieta , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Higiene Bucal , Fatores de Risco , Saliva/química , Desmineralização do Dente/etiologia , Adulto Jovem
12.
Microsc Res Tech ; 78(11): 1019-25, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26397964

RESUMO

Sixty samples of human dentin were divided into six groups (n = 10) and were irradiated with Er:YAG laser at 100 mJ-19.9 J/cm(2), 150 mJ-29.8 J/cm(2), 100 mJ-35.3 J/cm(2), 150 mJ-53.0 J/cm(2), 200 mJ-70.7 J/cm(2), and 250 mJ-88.5 J/cm(2), respectively, at 7 Hz under a water spray. The atomic percentages of carbon, oxygen, magnesium, calcium, and phosphorus and the Ca-to-P molar ratio on the dentin were determined by energy dispersive X-ray spectroscopy. The morphological changes were observed using scanning electron microscopy. A paired t-test was used in statistical analysis before and after irradiation, and a one-way ANOVA was performed (P ≤ 0.05). The atomic percent of C tended to decrease in all of the groups after irradiation with statistically significant differences, O and Mg increased with significant differences in all of the groups, and the Ca-to-P molar ratio increased in groups IV, V, and VI, with statistically significant differences between groups II and VI. All the irradiated samples showed morphological changes. Major changes in the chemical composition of dentin were observed in trace elements. A significant increase in the Ca-to-P ratio was observed in the higher energy density groups. Morphological changes included loss of smear layer with exposed dentinal tubules. The changes produced by the different energy densities employed could have clinical implications, additional studies are required to clarify them.


Assuntos
Dentina/química , Dentina/efeitos da radiação , Lasers de Estado Sólido , Terapia com Luz de Baixa Intensidade , Propriedades de Superfície , Cálcio/análise , Carbono/análise , Elementos , Humanos , Magnésio/análise , Microscopia Eletrônica de Varredura , Oxigênio/análise , Fósforo/análise , Camada de Esfregaço/ultraestrutura , Espectrometria por Raios X
13.
J Appl Oral Sci ; 23(3): 321-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26221928

RESUMO

The use of nanoparticles (NPs) has become a significant area of research in Dentistry. Objective The aim of this study was to investigate the physical, antibacterial activity and bond strength properties of conventional base, core build and restorative of glass ionomer cement (GIC) compared to GIC supplemented with titanium dioxide (TiO2) nanopowder at 3% and 5% (w/w). Material and Methods Vickers microhardness was estimated with diamond indenter. Compressive and flexural strengths were analyzed in a universal testing machine. Specimens were bonded to enamel and dentine, and tested for shear bond strength in a universal testing machine. Specimens were incubated with S. mutans suspension for evaluating antibacterial activity. Surface analysis of restorative conventional and modified GIC was performed with SEM and EDS. The analyses were carried out with Kolmogorov-Smirnov, ANOVA (post-hoc), Tukey test, Kruskal-Wallis, and Mann Whitney. Results Conventional GIC and GIC modified with TiO2 nanopowder for the base/liner cement and core build showed no differences for mechanical, antibacterial, and shear bond properties (p>0.05). In contrast, the supplementation of TiO2 NPs to restorative GIC significantly improved Vickers microhardness (p<0.05), flexural and compressive strength (p<0.05), and antibacterial activity (p<0.001), without interfering with adhesion to enamel and dentin. Conclusion GIC supplemented with TiO2 NPs (FX-II) is a promising material for restoration because of its potential antibacterial activity and durable restoration to withstand the mastication force.


Assuntos
Antibacterianos/química , Colagem Dentária/métodos , Cimentos de Ionômeros de Vidro/química , Nanopartículas/química , Titânio/química , Análise de Variância , Força Compressiva , Esmalte Dentário/efeitos dos fármacos , Dentina/efeitos dos fármacos , Testes de Dureza , Teste de Materiais , Microscopia Eletrônica de Varredura , Maleabilidade , Valores de Referência , Resistência ao Cisalhamento , Estatísticas não Paramétricas , Streptococcus mutans/efeitos dos fármacos , Propriedades de Superfície
14.
J. appl. oral sci ; 23(3): 321-328, May-Jun/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-752432

RESUMO

The use of nanoparticles (NPs) has become a significant area of research in Dentistry. Objective The aim of this study was to investigate the physical, antibacterial activity and bond strength properties of conventional base, core build and restorative of glass ionomer cement (GIC) compared to GIC supplemented with titanium dioxide (TiO2) nanopowder at 3% and 5% (w/w). Material and Methods Vickers microhardness was estimated with diamond indenter. Compressive and flexural strengths were analyzed in a universal testing machine. Specimens were bonded to enamel and dentine, and tested for shear bond strength in a universal testing machine. Specimens were incubated with S. mutans suspension for evaluating antibacterial activity. Surface analysis of restorative conventional and modified GIC was performed with SEM and EDS. The analyses were carried out with Kolmogorov-Smirnov, ANOVA (post-hoc), Tukey test, Kruskal-Wallis, and Mann Whitney. Results Conventional GIC and GIC modified with TiO2 nanopowder for the base/liner cement and core build showed no differences for mechanical, antibacterial, and shear bond properties (p>0.05). In contrast, the supplementation of TiO2 NPs to restorative GIC significantly improved Vickers microhardness (p<0.05), flexural and compressive strength (p<0.05), and antibacterial activity (p<0.001), without interfering with adhesion to enamel and dentin. Conclusion GIC supplemented with TiO2 NPs (FX-II) is a promising material for restoration because of its potential antibacterial activity and durable restoration to withstand the mastication force. .


Assuntos
Antibacterianos/química , Colagem Dentária/métodos , Cimentos de Ionômeros de Vidro/química , Nanopartículas/química , Titânio/química , Análise de Variância , Força Compressiva , Esmalte Dentário/efeitos dos fármacos , Dentina/efeitos dos fármacos , Testes de Dureza , Teste de Materiais , Microscopia Eletrônica de Varredura , Maleabilidade , Valores de Referência , Resistência ao Cisalhamento , Estatísticas não Paramétricas , Propriedades de Superfície , Streptococcus mutans/efeitos dos fármacos
15.
J Conserv Dent ; 17(6): 536-40, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25506140

RESUMO

BACKGROUND: Chemomechanical caries removal system is part of the minimal invasive dentistry; the aim of the study was to compare the amount of bacteria after caries removal with chemomechanical system and conventional rotatory instruments and to test the Vickers microhardness and micro-RAMAN analysis of residual dentin after excavation. MATERIALS AND METHODS: Molars were induced for demineralization, confirmed with DIAGNOdent; Streptococcus mutans were inoculated into the cavities and filled. Caries removal was performed with rotatory instruments and chemomechanical system; surviving bacteria were cultured for 24 and 48 hours at 37°C. Vickers microhardness and micro-RAMAN analysis were tested after excavation. Data were analyzed with Wilcoxon, continuity correction, odds ratio, ANOVA post hoc Tukey test, and Spearman correlation. RESULTS: Demineralization was significantly detectable at 240 hours of incubation; conventional rotatory instruments and chemomechanical caries removal were effective in 19.4%-22.6% and 25.8%-32.3%, respectively. Vickers microhardness of chemomechanical system was higher (P < 0.0001) than conventional rotatory instruments and comparable to healthy dentin. Micro-RAMAN analysis showed that healthy dentin is correlated to chemomechanical system (R (2) = 0.683, P < 0.00001) and drilling with burs (R (2) = 0.139, P < 0.00001). CONCLUSION: The chemomechanical system is effective for caries elimination, comparable to conventional rotatory instruments; the remaining Vickers microhardness and composition surface tissue are similar to healthy dentin.

16.
Rev Invest Clin ; 65(3): 228-36, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-23877810

RESUMO

OBJECTIVE: To determine the experience, prevalence and severity of dental caries and its relationship with nutritional status in nursery infants 17 to 47 months of age. MATERIAL AND METHODS: A cross-sectional study in 152 infants 17 to 47 months of age attending one of five day care centers of the city of Pachuca, Hidalgo was performed. Clinical examinations were performed using the methods recommended by the World Health Organization for epidemiologic studies on dental caries. We calculated the caries index (dmft), the significant caries index (SiC) as well as the treatment needs index (TNI) and the care index (CI). Nutritional status was determined using the weight and height for age, in Federico Gomez's scale. In the statistical analysis nonparametric tests were used. RESULTS: Mean age was 2.52 ± 0.76 years; 51.3% were boys. With regard to nutritional status, 19.1% were classified as malnourished and 19.1% were overweight/obese. The dmft index was 1.53 ± 2.52. The SiC index was 4.14, the TNI 86.3% and the CI 13.7%. Caries prevalence was 48.0%. It was observed that 33.5% of children had 1 to 3 teeth with caries experience and 14.5% had 4 or more teeth affected. Statistically significant differences for tooth decay were identified (p < 0.05) by age, height and weight but not (p> 0.05) by sex and nutritional status. CONCLUSIONS: This study shows that nearly half of children examined had caries experience. High treatment needs for dental caries were observed. A correlation was found between dmft index and age, weight and height. No association was identified between experience, prevalence and severity of dental caries and nutritional status of infants. It appears necessary to improve oral health preventive measures in these infants.


Assuntos
Cárie Dentária/epidemiologia , Estado Nutricional , Estatura , Peso Corporal , Pré-Escolar , Comorbidade , Estudos Transversais , Índice CPO , Feminino , Humanos , Lactente , Masculino , Desnutrição/epidemiologia , México/epidemiologia , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Prevalência
17.
J Appl Oral Sci ; 20(5): 544-9, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23138741

RESUMO

UNLABELLED: In orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms. OBJECTIVE: The purpose of this study was to quantitatively determine the independent bacterial colonization of S. mutans and S. sobrinus in orthodontic composite resins. MATERIAL AND METHODS: Seven orthodontic composite adhesives for bonding brackets were selected and classified into 14 groups; (GIm, GIs) Enlight, (GIIm, GIIs) Grengloo, (GIIIm, GIIIs) Kurasper F, (GIVm, GIVs) BeautyOrtho Bond, (GVm, GVs) Transbond CC, (GVIm, GVIs) Turbo Bond II, (GVIIm, GVIIs) Blugloo. 60 blocks of 4x4x1 mm of each orthodontic composite resin were made (total 420 blocks), and gently polished with sand-paper and ultrasonically cleaned. S. mutans and S. sobrinus were independently cultivated. For the quantitative analysis, a radioactive marker was used to codify the bacteria (³H) adhered to the surface of the materials. The blocks were submerged in a solution with microorganisms previously radiolabeled and separated (210 blocks for S. mutans and 210 blocks for S. sobrinus) for 2 hours at 37 ºC. Next, the blocks were placed in a combustion system, to capture the residues and measure the radiation. The statistical analysis was calculated with the ANOVA test (Sheffè post-hoc). RESULTS: Significant differences of bacterial adhesion were found amongst the groups. In the GIm and GIs the significant lowest scores for both microorganisms were shown; in contrast, the values of GVII for both bacteria were significantly the highest. CONCLUSIONS: This study showed that the orthodontic composite resin evaluated in the GIm and GIs, obtained the lowest adherence of S. mutans and S. sobrinus, which may reduce the enamel demineralization and the risk of white spot lesion formation.


Assuntos
Aderência Bacteriana/fisiologia , Resinas Compostas , Cimentos Dentários , Braquetes Ortodônticos/microbiologia , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus sobrinus/crescimento & desenvolvimento , Resinas Acrílicas , Análise de Variância , Carga Bacteriana , Bis-Fenol A-Glicidil Metacrilato , Polimento Dentário , Ácidos Fosfóricos , Cimentos de Resina , Propriedades de Superfície
18.
J. appl. oral sci ; 20(5): 544-549, Sept.-Oct. 2012. tab
Artigo em Inglês | LILACS | ID: lil-654919

RESUMO

In Orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms. OBJECTIVE: The purpose of this study was to quantitatively determine the independent bacterial colonization of S. mutans and S. sobrinus in orthodontic composite resins. MATERIAL AND METHODS: Seven orthodontic composite adhesives for bonding brackets were selected and classified into 14 groups; (GIm, GIs) Enlight, (GIIm, GIIs) Grengloo, (GIIIm, GIIIs) Kurasper F, (GIVm, GIVs) BeautyOrtho Bond, (GVm, GVs) Transbond CC, (GVIm, GVIs) Turbo Bond II, (GVIIm, GVIIs) Blugloo. 60 blocks of 4x4x1 mm of each orthodontic composite resin were made (total 420 blocks), and gently polished with sand-paper and ultrasonically cleaned. S. mutans and S. sobrinus were independently cultivated. For the quantitative analysis, a radioactive marker was used to codify the bacteria (³H) adhered to the surface of the materials. The blocks were submerged in a solution with microorganisms previously radiolabeled and separated (210 blocks for S. mutans and 210 blocks for S. sobrinus) for 2 hours at 37ºC. Next, the blocks were placed in a combustion system, to capture the residues and measure the radiation. The statistical analysis was calculated with the ANOVA test (Sheffè post-hoc). RESULTS: Significant differences of bacterial adhesion were found amongst the groups. In the GIm and GIs the significant lowest scores for both microorganisms were shown; in contrast, the values of GVII for both bacteria were significantly the highest. CONCLUSIONS: This study showed that the orthodontic composite resin evaluated in the GIm and GIs, obtained the lowest adherence of S. mutans and S. sobrinus, which may reduce the enamel demineralization and the risk of white spot lesion formation.


Assuntos
Aderência Bacteriana/fisiologia , Resinas Compostas , Cimentos Dentários , Braquetes Ortodônticos/microbiologia , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus sobrinus/crescimento & desenvolvimento , Resinas Acrílicas , Análise de Variância , Carga Bacteriana , Bis-Fenol A-Glicidil Metacrilato , Polimento Dentário , Ácidos Fosfóricos , Cimentos de Resina , Propriedades de Superfície
19.
Am J Orthod Dentofacial Orthop ; 136(3): 425-30, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19732677

RESUMO

INTRODUCTION: The purpose of this study was to compare the shear bond strength (SBS) of orthodontic brackets bonded with 4 self-etching adhesives. METHODS: A total of 175 extracted premolars were randomly divided into 5 groups (n = 35). Group I was the control, in which the enamel was etched with 37% phosphoric acid, and stainless steel brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif). In the remaining 4 groups, the enamel was conditioned with the following self-etching primers and adhesives: group II, Transbond Plus and Transbond XT (3M Unitek); group III, Clearfil Mega Bond FA and Kurasper F (Kuraray Medical, Tokyo, Japan); group IV, Primers A and B, and BeautyOrtho Bond (Shofu, Kyoto, Japan); and group V, AdheSE and Heliosit Orthodontic (Ivoclar Vivadent AG, Liechtenstein). The teeth were stored in distilled water at 37 degrees C for 24 hours and debonded with a universal testing machine. The adhesive remnant index (ARI) including enamel fracture score was also evaluated. Additionally, the conditioned enamel surfaces were observed under a scanning electron microscope. RESULTS: The SBS values of groups I (19.0 +/- 6.7 MPa) and II (16.6 +/- 7.3 MPa) were significantly higher than those of groups III (11.0 +/- 3.9 MPa), IV (10.1 +/- 3.7 MPa), and V (11.8 +/- 3.5 MPa). Fluoride-releasing adhesives (Kurasper F and BeautyOrtho Bond) showed clinically acceptable SBS values. Significant differences were found in the ARI and enamel fracture scores between groups I and II. CONCLUSIONS: The 4 self-etching adhesives yielded SBS values higher than the bond strength (5.9 to 7.8 MPa) suggested for routine clinical treatment, indicating that orthodontic brackets can be successfully bonded with any of these self-etching adhesives.


Assuntos
Colagem Dentária , Braquetes Ortodônticos , Cimentos de Resina/química , Condicionamento Ácido do Dente , Resinas Acrílicas/química , Adesividade , Ligas Dentárias/química , Esmalte Dentário/lesões , Esmalte Dentário/ultraestrutura , Análise do Estresse Dentário/instrumentação , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Ácidos Fosfóricos/química , Resistência ao Cisalhamento , Aço Inoxidável/química , Estresse Mecânico , Propriedades de Superfície , Temperatura , Fatores de Tempo , Água/química
20.
Dent Mater J ; 28(1): 102-12, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19280975

RESUMO

This study was conducted to examine the ultrastructures of eight recently improved light-cure restorative composite resins with scanning and transmission electron microscopes (SEM and TEM). Additionally, Vickers hardness, volume/weight fraction of filler, and chemical composition were analyzed. Composite resins selected for evaluation were Beautifil II, Clearfil AP-X, Clearfil Majesty, Estelite sigma, Filtek Supreme, Filtek Z250, Solare, and Synergy. SEM and TEM images revealed a great diversity in ultrastructure, and Vickers hardness test showed significant differences amongst all the composite resins (except between Clearfil Majesty and Estelite sigma, and between Filtek Supreme and Filtek Z250). By means of EDX, similar elements such as C, O, and Si were detected, but the concentration was different in every composite resin. Results obtained in this study served to validate that the methods employed in this study SEM and TEM at high magnification--were useful in examining the ultrastructures of composite resins. It was also found that the ultrastructure, size of filler particles, volume/weight fraction of filler, and chemical composition of the composite resins had an effect on Vickers hardness. Given the great diversity of ultrastructures amongst the composite resins, which stemmed from the different revolutionary technologies used to manufacture them, further studies are warranted in the search of clinical applications that optimally match the differing properties of these materials.


Assuntos
Resinas Compostas/química , Materiais Dentários/química , Condicionamento Ácido do Dente , Bis-Fenol A-Glicidil Metacrilato/análise , Bis-Fenol A-Glicidil Metacrilato/química , Carbono/análise , Resinas Compostas/análise , Materiais Dentários/análise , Polimento Dentário/instrumentação , Microanálise por Sonda Eletrônica , Dureza , Humanos , Metacrilatos/análise , Metacrilatos/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxigênio/análise , Tamanho da Partícula , Silício/análise , Propriedades de Superfície
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