S-PRG-based toothpastes compared to NaF toothpaste and NaF varnish on dentin permeability in vitro

Objectives: To analyze the effect of 5 toothpastes containing different percentages of S-PRG fillers compared to NaF toothpaste and NaF varnish on the dentin hydraulic conductance (Lp). Methodology: Dentin disks (1.0±0.2 mm thickness) were cut from third molars, and their Lp values were evaluated using Flodec. The specimens were allocated into 7 groups (n=8). The minimum (smear layer) and the maximum (after acid etching) Lp values were recorded. Lp was also assessed after treatment with either a 0wt.%, 1wt.%, 5wt.%, 20wt.%, or 30wt.% S-PRG toothpaste, a NaF toothpaste, or a NaF varnish. Toothpastes were applied by brushing for 15 s, allowing it to settle for 1 min, and rinsing with deionized water. The NaF varnish was applied for 4 min and was removed with a probe. Specimens were exposed to citric acid (6%, pH 2.1, 1 min) and their final Lp was recorded. The pH of all products was recorded (n=3) and specimens from each group were analyzed by Laser Scanning Confocal Microscopy (LSCM). Data were subjected to 2-way repeated measures ANOVA and post-hoc Bonferroni (a=0.05). Results: The highest Lp reduction was noticed for the 5wt.% S-PRG toothpaste, NaF toothpaste, and NaF varnish. However, the toothpastes containing 5wt.%, 20wt.%, and 30wt.% of S-PRG were similar to all toothpastes but differed from the NaF varnish. After erosion, all groups retrieved their maximum Lp values, except for the NaF varnish. The LSCM evidenced deposits on the surface of specimens treated with 5%, 20%, and 30% S-PRG-based toothpastes and NaF toothpaste. Even more deposits were observed for the NaF varnish. After the erosive challenge, the deposits were diminished in all groups. Conclusion: Toothpastes containing 5wt.%, 20wt.%, and 30wt.% of S-PRG fillers behaved similarly to a conventional NaF toothpaste, even after an erosive challenge. The NaF varnish promoted better reduction of the Lp, but its effect was also diminished after erosion

Caracterizações estrutural, química e óptica de uma cerâmica experimental de SiO2-Y-TZP produzida pela técnica de prensagem uniaxial/isostática

New glass ceramics enriched by polycrystalline materials has been produced by different processing methods. However, for these materials to be used as restorative dental materials in esthetical areas they must count with good optical properties, which are directly influenced by their structure and chemical composition. For these reasons, the aim of this study was to produce a new glass ceramic containing SiO2+Y-TZP via uniaxial/isostatic powder compression and to structurally and chemically characterize this material relating to its optical properties. SiO2 and Zpex® were used as starting powders. These two powders were mixed (97w%-3% ratio) and pressed in uniaxial (80MPa) and isostatic (206MPa) press and sintered at 1150ºC for 2h. The starting powders, the mixed powder (before sintering) and the sintered specimens were submitted to Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM/EDX), Transmission Electron Microscope (TEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The materials density was measured. The contrast ratio and translucency parameter of the sintered specimen were compared to lithium disilicate (IPS e.max® CAD HT A1) and zirconia-reinforced lithium silicate (Celtra Duo® HT A1), using Kruskal-Wallis and post-hoc Dunn tests with a significance level set at 5%. Agglomerations of SiO2 and Zpex could be seen under SEM/EDX analysis due to their reduced particle size, yet, when sintered, some remaining porosities could be seen. The TEM analysis evidenced the spherical character of SiO2 grains and the crystallographic pattern of the Zpex particles. When mixed, Zpex can be seen inside the grain of SiO2. XDR analysis pointed out that SiO2 was amorphous, and Zpex presented monoclinic (m) and tetragonal (t) peaks. After sintering, crystallization of SiO2 can be seen without new m peaks. The FTIR spectra bands suggested an interaction between Si, O and Zr. The theoretical density value of the experimental ceramics was 1.663 g/cm3. The contrast ratio and the translucency parameter of the experimental ceramic were higher (p=0,000001) and lower (p=0,000001), respectively, than those of lithium disilicate and zirconia-reinforced lithium silicate. It can be concluded that the uniaxial/isostatic powder compression is an efficient method to obtain experimental ceramics for dental purposes and 1150ºC for 2h is sufficient to crystallize SiO2 without inducing t-m transformation of zirconia. Yet, this sintering protocol seems to be insufficient to densify the experimental ceramic, which may the reason for its lack of translucency.Novas cerâmicas vítreas enriquecidas por materiais policristalinos tem sido produzidas por diferentes métodos de processamento. Entretanto, para que sejam utilizados como materiais restauradores odontológicos em áreas estéticas, eles devem apresentar boas propriedades ópticas, que estão diretamente influenciadas por sua estrutura e composição química. Por esses motivos, o objetivo deste estudo foi produzir uma nova cerâmica vítrea contendo SiO2+Y-TZP através da via uniaxial/isostática, e caracterizar este material estrutural e quimicamente, relacionando às suas propriedades ópticas. SiO2 e Zpex® foram usados como pós de partida, misturados (97m%-3m%), prensados em prensa uniaxial (80MPa) e isostática (206MPa) e sinterizados à 1150ºC por 2h. Os pós de partida, o pó após a mistura (prévio à sinterização) e a amostra sinterizada foram submetidos à Microscopia Eletrônica de Varredura/Espectroscopia por Energia Dispersiva de Raios-X (MEV-EDX), Microscopia Eletrônica de Transmissão (MET), Difração de Raios-X (DRX) e Espectroscopia de Infravermelho com Transformada de Fourier (FTIR). A densidade do material foi mensurada. A razão de contraste e o parâmetro de translucidez da amostra sinterizada foram comparados aos do dissilicato de lítio (IPS e.max® CAD HT A1) e do silicato de lítio reforçado por zircônia (Celtra Duo® HT A1), utilizando os testes de Kruskal-Wallis e post-hoc Dunn com nível de significância de 5%. Aglomerações SiO2 e Zpex foram vistas sob MEV/EDX devido ao tamanho reduzido das partículas, porém, quando sinterizado, algumas porosidades puderam ser vistas. A análise em MET evidenciou o caráter esférico dos grãos de SiO2 e o padrão cristalográfico das partículas de Zpex. Quando misturados, Zpex pode ser visto dentro de uma partícula de SiO2. A análise em DRX destacou que a SiO2 era amorfo e Zpex apresentava picos monoclínicos (m) e tetragonais (t). Após a sinterização, a cristalização da SiO2 pode ser vista sem a formação de novos picos m. As bandas do espectro do FTIR sugeriram uma interação entre Si, O e Zr. A densidade do material foi 1,663g/cm3. A razão de contraste e o parâmetro de translucidez da cerâmica foi maior (p=0,000001) e menor (p=0,000001), respectivamente, que os do silicato de lítio e do silicato de lítio reforçado por zircônia. Podese concluir que a compressão dos pós em prensa uniaxial/isostática é um método eficiente em produzir cerâmicas experimentais para uso odontológico, e que 1150ºC por 2h é suficiente para cristalizar o SiO2 sem induzir transformação t-m na zirconia. Contudo, esse protocolo de sinterização parece ser insuficiente para densificar a cerâmica experimental, o que pode prejudicar sua translucidez

Presence of Serum Ferritin before and after Bariatric Surgery: Analysis in Dentate and Edentulous Patients.

Society has changed its own lifestyle, specially its eating habits and physical activities, leading to excessive weight and a sedentary behavior, which has contributed to obesity increase. Bariatric surgery is the most effective treatment to obesity, allowing weight loss and its maintenance. However, it has been related high levels of iron deficiency after surgery. A person's nutritional status might be affected by total or partial tooth loss. The aim of this longitudinal prospective cohort study was to evaluate the levels of serum ferritin before and after bariatric surgery and to identify if there is a relation with tooth loss. The sample was composed of 50 patients selected and assisted at Amaral Carvalho Hospital, located in Jaú city, Brazil. The use and necessity of prosthesis, dental absence or presence, and serum ferritin dosage were evaluated. Student's t test, Univariate analysis, Chi-square and Odds Ratio were adopted (p<0.05). There was no significant difference regarding the serum ferritin levels between dentate and edentulous patients prior to surgery (p = 0.436). After surgery, the serum ferritin levels were higher in edentulous patients (prosthesis users) when compared to the pre-surgical levels, and the post-surgical levels presented significant difference regarding the dentate patients (p = 0.024). It can be concluded that rehabilitated patients in postoperative period showed better levels of serum ferritin after surgical intervention

Presence of serum ferritin before and after bariatric surgery: analysis in dentate and edentulous patients

Society has changed its own lifestyle, specially its eating habits and physical activities, leading to excessive weight and a sedentary behavior, which has contributed to obesity increase. Bariatric surgery is the most effective treatment to obesity, allowing weight loss and its maintenance. However, it has been related high levels of iron deficiency after surgery. A person's nutritional status might be affected by total or partial tooth loss. The aim of this longitudinal prospective cohort study was to evaluate the levels of serum ferritin before and after bariatric surgery and to identify if there is a relation with tooth loss. The sample was composed of 50 patients selected and assisted at Amaral Carvalho Hospital, located in Jau A city, Brazil. The use and necessity of prosthesis, dental absence or presence, and serum ferritin dosage were evaluated. Student's t test, Univariate analysis, Chi-square and Odds Ratio were adopted (p<0.05). There was no significant difference regarding the serum ferritin levels between dentate and edentulous patients prior to surgery (p = 0.436). After surgery, the serum ferritin levels were higher in edentulous patients (prosthesis users) when compared to the pre-surgical levels, and the post-surgical levels presented significant difference regarding the dentate patients (p = 0.024). It can be concluded that rehabilitated patients in postoperative period showed better levels of serum ferritin after surgical intervention1110CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2012/10994-0; 2015/05749-

Distribution of the sample according to oral health

<p>Distribution of the sample according to oral health</p

Univariate analysis of serum ferritin levels preoperatively according to the condition of present and absent teeth.

<p>Univariate analysis of serum ferritin levels preoperatively according to the condition of present and absent teeth.</p

Used criteria to characterize the serum ferritin levels.

<p>Used criteria to characterize the serum ferritin levels.</p

Comparison of loss percentage of excess weight after 3 months of surgery between dentate and rehabilitated patients.

<p>Comparison of loss percentage of excess weight after 3 months of surgery between dentate and rehabilitated patients.</p

Study design.

<p>Study design.</p

Missing teeth in edentulous patients.

<p>Missing teeth in edentulous patients.</p