The impact of synthetic bone grafting for tissue regeneration: an in vivo study

Aims: This study aimed to examine the biological response of synthetic nanocomposite material on canine mandibular bone. Methods: Nine healthy adult male local breed dogs aged 12 to 18 months and weighing 10.2 to 15.2 kg were used in the study. Based on healing intervals of 1 and 2 months, the dogs were divided into 2 groups. Each group had 3 subgroups with 3 dogs each. The division was based on the grafting material used to fill the created defect: an empty defect (Control-ve), Beta-Tricalcium Phosphate, and nanocomposite (Beta-Tricalcium Phosphate and nanosilver 1%) . Surgery started after the dogs were anaesthetized. The surgical procedure began with a 5 cm parallel incision along the mandible's lower posterior border. After exposing the periosteum, a three 5mm-diameter, 5-mmdeep critical-size holes were made, 5mm between each one. Each group's grafting material had independent 3 holes. The defects were covered with resorbable collagen membranes followed by suturing of the mucoperiosteal flap. Results: Total densitometric analysis showed no significant differences between groups at 1-month intervals, with the nanocomposite group having a higher mean rank (165.66± 31.21) in comparison to other groups while at 2 months intervals that there was a highly significant difference between three groups as the P-value was (0.000) with the nanocomposite group having a higher mean rank (460.66± 26.40). Conclusions: In the current study, the use of nanocomposites improved osteoconductivity by accelerating new bone formation. Moreover, the encorporation of nanosilver enhanced growth factor activity. These attributes make nanocomposites a promising material for enhancing the bone healing process

Effect of fluoride gels with nano-sized sodium trimetaphosphate on the in vitro remineralization of caries lesions

Abstract Objective To evaluate the effects of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) on the in vitro remineralization of caries-like lesions. Methodology Bovine enamel subsurface lesions (n=168) were selected according to their surface hardness (SH) and randomly divided into seven groups (n=24/group): Placebo (without F/TMP), 4,500 ppm F (4500F), 4500F + 2.5% TMPnano (2.5% Nano), 4500F + 5% TMPnano (5% Nano), 4500F + 5% TMPmicro (5% Micro), 9,000 ppm F (9000F), and 12,300 ppm F (Acid gel). The gels were applied in a thin layer for one minute. Half of the blocks were subjected to pH cycling for six days, whereas the remaining specimens were used for loosely- (calcium fluoride; CaF2) and firmly-bound (fluorapatite; FA) fluoride analysis. The percentage of surface hardness recovery (%SHR), area of subsurface lesion (ΔKHN), CaF2, FA, calcium (Ca), and phosphorus (P) on/in enamel were determined. Data (log10-transformed) were subjected to ANOVA and the Student-Newman-Keuls' test (p<0.05). Results We observed a dose-response relation between F concentrations in the gels without TMP for %SHR and ΔKHN. The 2.5% Nano and 5% Micro reached similar %SHR when compared with 9000F and Acid gels. For ΔKHN, Placebo and 5% Nano gels had the highest values, and 5% Micro, 2.5% Nano, 9000F, and Acid gels, the lowest. All groups had similar retained CaF2 values, except for Placebo and Acid gel. We verified observed an increase in Ca concentrations in nano-sized TMP groups. Regarding P, TMP groups showed similar formation and retention to 9000F and Acid. Conclusion Adding 2.5% nano-sized or 5% micrometric TMP to low-fluoride gels lead to enhanced in vitro remineralization of artificial caries lesions.

Physico-chemical and biological properties of different magnesium modified calcium phosphate bone cements / 中华创伤杂志

Objective:To investigate the physicochemical and biological properties of different magnesium modified calcium phosphate bone cements.Methods:The different magnesium modified calcium phosphate bone cements were divided into magnesium citrate, magnesium lactate, magnesium malate, magnesium phosphate and magnesium glycinate groups, each of which was added with different magnesium agents in the proportion of 0%, 1%, 3% and 5% of the total weight of calcium phosphate bone cements. The initial and final setting time, injectability, anti-collapse performance and compressive strength of different magnesium modified calcium phosphate bone cements were tested. Furthermore, the screened bone cement extracts were used to culture with third generation osteoblasts. Bioactivity assays were performed using the Cell Proliferation and Toxicity Assay Kit (CCK-8). Alkaline phosphatase (ALP) staining and Alizarin Red S (ARS) staining were performed on osteoblasts to observe the osteogenic activity of magnesium malate modified calcium phosphate bone cements.Results:The addition of different proportions of different magnesium agents led to the shortening of the initial and final setting time of modified calcium phosphate bone cements. Moreover, the final setting time of 5% magnesium malate modified calcium phosphate bone cements was the shortest (<40 minutes), which was significantly shorter compared with other magnesium agents in the same proportion (all P<0.05). With the addition of different magnesium agents in different proportions, the injectability of bone cements was gradually increased, and the injectability of 5% magnesium malate calcium phosphate bone cements reached the highest for (87.3±1.9)%, which was significantly increased compared with other magnesium agents in the same proportion (all P<0.05). The anti-collapse performance of bone cements was decreased with the addition of different magnesium agents in different proportions. Magnesium citrate, magnesium phosphate and magnesium glycinate modified calcium phosphate bone cements could not resist the flushing of deionized water. In particular, magnesium malate modified calcium phosphate bone cements had the best anti-collapse performance, with the maximum weight loss rate for only (9.8±2.3)% after 30 minutes of deionized water flushing, which was better than the rest of the groups (all P<0.05). The compressive strength of magnesium lactate and magnesium phosphate modified calcium phosphate bone cements showed a decrease compared with original calcium phosphate bone cements, while the compressive strength of magnesium citrate and magnesium malate modified calcium phosphate bone cements was significantly increased compared with original calcium phosphate bone cements, of which 3% magnesium malate modified calcium phosphate bone cements had the greatest compressive strength of (6.2±0.2)MPa, significantly higher than the rest of the groups (all P<0.05). The sieve test yielded magnesium malate modified calcium phosphate bone cement, which had a weight loss of (27.0±0.9)% at 35 days in vitro. The release of magnesium ions was increased with increasing magnesium malate dose in the in vitro environment of magnesium malate modified calcium phosphate bone cements in different ratios. A stable magnesium ion release was achieved within 35 days.Also, the pro-proliferative and osteogenic effects of modified calcium phosphate bone cements on osteoblasts were more obvious with increase of magnesium malate dose. For 5% magnesium malate modified calcium phosphate bone cements, the cell number, ALP staining area ratio and calcium nodule area ratio were significantly increased compared with the groups in the proportion of 0% and 1% magnesium malate (all P<0.05). Conclusions:Among magnesium citrate, magnesium lactate, magnesium malate, magnesium phosphate and magnesium glycinate modified calcium phosphate bone cements, magnesium malate modified calcium phosphate bone cements have relatively suitable setting time, excellent anti-collapse performance and mechanical strength. Meanwhile, 5% magnesium malate modified calcium phosphate bone cements have better biological activity among different ratios of magnesium malate modified calcium phosphate bone cements, suggesting a potential value for clinical application.

Barniz polimerizable de vidrio ionómero modificado con resina "clinpro xt": una alternativa de tratamiento para la sensibilidad dentaria. Revisión sistemática de la literatura

Resumen Introducción: En respuesta a la sensibilidad dentinaria, se han desarrollado múltiples productos, entre ellos, Clinpro XT, barniz de vidrio ionómero modificado con resina fotopolimerizable con flúor, calcio y fosfato. Metodología: Se realizó una revisión sistemática de la literatura. La selección fue en base a título, resumen y texto completo de acuerdo a los criterios de inclusión y exclusión. Resultados: De 299 artículos, fueron seleccionados revisiones sistemáticas, metaanálisis, estudios in vivo e in vitro y 2 encuestas. Discusión: Clinpro XT reduce la permeabilidad dentinaria, ocluye túbulos dentinarios e inhibe su reapertura, aumenta la biodisponibilidad de minerales en saliva y promueve la remineralización del esmalte. Significando una mayor protección del esmalte y dentina de forma inmediata y a largo plazo. Conclusiones: Clinpro XT demostró disminuir la hipersensibilidad dentinaria incluso después 6 meses posterior a su aplicación.

Resumo Introdução: Em resposta à sensibilidade dentinária, foram desenvolvidos múltiplos produtos, incluindo Clinpro XT, um verniz de vidro de ionómero modificado com resina fotopolimerizável com flúor, cálcio, e fosfato. Metodologia: Foi realizada uma revisão sistemática da literatura. A selecção foi baseada no título, resumo e texto completo de acordo com os critérios de inclusão e exclusão. Resultados: De 299 artigos, revisões sistemáticas, meta-análises, estudos in vivo e in vitro e 2 inquéritos foram seleccionados. Discussão: Clinpro XT reduz a permeabilidade da dentina, oclui os túbulos dentinários e inibe a sua reabertura, aumenta a biodisponibilidade dos minerais na saliva e promove a remineralização do esmalte. O que significa uma maior protecção do esmalte e da dentina imediatamente e a longo prazo. Conclusões: Foi demonstrado que o Clinpro XT diminui a hipersensibilidade da dentina mesmo 6 meses após a aplicação.

Abstract Introduction: Multiple products have been developed to treat dentin sensitivity, including Clinpro XT, a lightcuring resinmodified ionomer glass varnish with fluoride, calcium, and phosphate. Methodology: A systematic literature review was conducted. The articles were selected based on title, abstract, and full text according to the inclusion and exclusion criteria. Results: Of 299 articles, systematic reviews, metaanalysis, in vivo and in vitro studies, and 2 surveys were selected. Discussion Clinpro XT reduces dentin permeability, occludes dentin tubules, inhibits their reopening, increases mineral bioavailability in saliva, and promotes enamel remineralization. This entails greater protection of enamel and dentin immediately and in the long term. Conclusions: Clinpro XT was shown to decrease dentin hypersensitivity even six months after application.

Efeitos de nanopartículas de hexametafosfato de sódio, associadas ou não ao fluoreto, em biofilmes mistos de Streptococcus mutans e Candida albicans e em biofilmes microcosmos / Effects of sodium hexametaphosphate nanoparticles, combined or not with fluoride, on dual-species biofilms of Streptococcus mutans and Candida albicans and on microcosm biofilms

O presente estudo avaliou os efeitos de nanopartículas de hexametafosfato de sódio (HMPnano), associadas ou não ao fluoreto (F), na composição orgânica (Subprojeto 1- S1) e inorgânica (Subprojeto 2-S2) de biofilmes mistos de Streptococcus mutans e Candida albicans formados in vitro; e na viabilidade celular e atividade metabólica de biofilmes microcosmos derivados de saliva (Subprojeto 3-S3). Em S1 e S2, soluções de HMPnano ou HMP microparticulado (HMPmicro) foram preparadas a 0,5% ou 1%, com ou sem F (1100 ppm F, NaF), além de 1100 ppm F (controle positivo) e saliva artificial (controle negativo). S. mutans e C. albicans foram cultivados em saliva artificial. Os biofilmes foram formados no fundo de poços de placas de microtitulação e tratados 72, 78 e 96 horas após o início da formação, por 1 minuto. Em S1, após o último tratamento, realizou-se análises de quantificação das unidades formadoras de colônias (UFCs), produção de biomassa total, atividade metabólica, além da composição da matriz extracelular dos biofilmes e avaliação estrutural. Observou-se que 1% de HMPnano combinado ao F levou aos menores UFCs de S. mutans, bem como às menores concentrações de carboidratos da matriz extracelular dos biofilmes, além de afetar substancialmente a sua estrutura. Em S2, após o último tratamento, avaliou-se o pH e a composição inorgânica dos biofilmes (análise das concentrações de F, cálcio (Ca) e fósforo (P)), antes e após exposição a sacarose. Soluções contendo 1% HMPnano combinado ao F promoveram os maiores valores de pH dos biofilmes, mesmo após exposição à sacarose. Além disso, 1% HMPnano promoveu maiores concentrações de P, enquanto que o HMP (micro/nano, com/sem F) levou a concentrações inexpressivas de Ca no fluido do biofilme. Em S3, os efeitos do HMPmicro ou HMPnano, sozinhos ou associados ao F, foram avaliados em biofilmes microcosmos derivados de saliva. Os biofilmes foram formados sobre discos de vidro por 24 h e, em seguida, S. mutans (C180- 2) foi incorporado ou não aos biofilmes. A partir deste momento, os mesmos ativos avaliados em S1/S2 foram adicionados ao meio de cultura, a 20% das concentrações utilizadas nesses subprojetos. Após 96 h de formação, foram determinadas as UFCs totais e de S. mutans, e avaliada a produção de ácido láctico pelos biofilmes. Todos os meios de cultura contendo contendo HMP levaram às menores concentrações de ácido láctico e às maiores reduções de UFCs totais e de S. mutans dos biofilmes, sem influência do tamanho da partícula de HMP, associação com F ou adição de S. mutans. Conclui-se que o HMPnano a 1%, associado a 1100 ppm F, promoveu uma diminuição substancial no metabolismo de biofilmes mistos de S. mutans e C. albicans, e da viabilidade de S. mutans. Esta combinação também levou a valores de pH mais próximos do neutro, além de afetar a composição inorgânica destes biofilmes. Para biofilmes microcosmos, o HMP promoveu a diminuição da viabilidade microbiana e acidogenicidade, sem influência, entretanto, do tamanho da partícula de HMP e da presença de F(AU)

This study evaluated the effects of sodium hexametaphosphate nanoparticles (HMPnano), combined or not with fluoride (F), on the organic (Subproject 1-S1) and inorganic (Subproject 2-S2) compositions of dual-species biofilms of Streptococcus mutans and Candida albicans formed in vitro; and on the cell viability and metabolic activity of saliva-derived microcosms biofilms (Subproject 3-S3). In S1 and S2, solutions containing HMPnano or conventional/micrometric HMP (HMPmicro) were prepared at 0.5 or 1%, combined or not with F (1,100 ppm F, as NaF). Also, a solution containing 1,100 ppm F and pure artificial saliva were tested as positive and negative controls, respectively. S. mutans and C. albicans strains were cultivated in artificial saliva. The biofilms were formed in well plates, and treated with the test solutions at 72, 78 and 96 from the beginning of the biofilm formation, for 1 minute. In S1, after the last treatment, the number of the colony-forming units (CFUs), production of total biomass, metabolic activity, composition of the extracellular matrix, and the structure of the biofilms were determined. HMP at 1% combined with F led to the lowest S. mutans CFUs and lowest concentration of carbohydrates from the extracellular matrix of the biofilms, besides substantially affecting biofilm's structure. In S2, after the last treatment, the pH and the inorganic composition of the biofilms (analysis of F, calcium (Ca), and phosphorus (P) concentrations), prior to and after sucrose exposure, were evaluated. Solutions containing 1% HMPnano combined with F led to the highest biofilm pH, even after exposure to sucrose. In addition, 1% HMPnano promoted the highest P concentrations, while HMP (micro/nano, with/without F) led to inexpressive Ca levels in the biofilm fluid. In S3, the effects of HMPmicro or HMPnano, alone or associated with F, were evaluated in salivaderived microcosm biofilms, which were formed during 24 h attached to glass coverslips. Thereafter, S. mutans (C180-2) was incorporated to the biofilms. From that timepoint onwards, the same actives analyzed in S1/S2 were added to the culture medium at 20% of the concentrations used in those subprojects. After 96 h of formation, total and S. mutans CFU-counting were determined, and the production of lactic acid was assessed. All HMP-containing culture media led to the lowest lactic acid concentrations, and to the highest reductions in total and S. mutans CFU counts, with no significant influence of HMP's particle size, association with F or the addition of S. mutans. In summary, it was concluded from S1 and S2 that 1% HMPnano combined with 1,100 ppm F substantially reduced the metabolism of S. mutans and C. albicans dual-species biofilms, besides reducing the viability of S. mutans. Also, this combination led to biofilm pH values closer to neutral ones, besides affecting their inorganic composition. From S3, HMP promoted reductions in the microbial viability and acidogenicity, without the influence, however, of HMP's particle size or the presence of F(AU)

Efeito do trimetafosfato de sódio micro e nanoparticulado, associadas ou não ao fluoreto, sobre biofilmes mistos de Streptococcus mutans e Candida albicans: avaliação da composição orgânica e inorgânica / Effect of micro and nanoparticulate sodium trimetaphosphate, associated or not with fluoride, on mixed biofilms of Streptococcus mutans and Candida albicans: evaluation of organic and inorganic composition

Este estudo avaliou o efeito de nanopartículas de TMP (TMPn) sobre a composição inorgânica e componentes da matriz extracelular de biofilmes mistos de Streptococcus mutans e Candida albicans. Biofilmes de duas espécies de S. mutans e C. albicans foram cultivados em saliva artificial em placas de 6 poços e tratados três vezes (72, 78 e 96 h após o início de sua formação), por 1 minuto, com soluções contendo TMP microparticulado (TMPm) e TMPn nas concentrações de 1% e 3%, combinadas ou não com 1100 ppm F. Além disso, solução de 1100 ppm F (F) e saliva artificial (CTL) foram testadas como controles positivos e negativos, respectivamente. Após o último tratamento, a composição da matriz extracelular foi analisada em termos de proteína e carboidrato, e o pH e as concentrações de F, cálcio (Ca), fósforo (P) e P do TMP da biomassa e fluido do biofilme foram determinadas. Em outro conjunto de experimentos, após o último tratamento, os biofilmes foram expostos a uma solução de sacarose a 20%, e o pH e componentes inorgânicos dos biofilmes foram avaliados conforme mencionado acima. Os dados de proteínas e carboidratos foram submetidos a ANOVA a 1 critério, seguido pelo teste de Student-Newman-Keuls, enquanto os dados da composição inorgânica do biofilme foram submetidos a ANOVA a 2 critérios, seguido pelo teste de Fisher LSD (p< 0,05). Tratamentos com TMPn a 3% combinado com F levou a reduções significativamente maiores nas concentrações de carboidratos da matriz extracelular, maior concentração iônica de F no fluido, e um pH significativamente mais alto, se comparado a todos os outros grupos. Além disso, TMPn a 3% sem F levou a concentrações de P significativamente mais altas em comparação a todos os outros grupos, antes da exposição a sacarose. Conclui-se que o TMPn afetou a composição da matriz extracelular, o pH dos biofilmes analisados, além de interferir nos componentes inorgânicos dos biofilmes ao aumentar os níveis de fósforo no fluido do biofilme(AU)

This study evaluated the effect of TMP nanoparticles (nTMP) on the inorganic composition and extracellular matrix components of mixed biofilms of Streptococcus mutans and Candida albicans. Biofilms of two species of S. mutans and C. albicans were cultivated in artificial saliva in 6-well plates and treated three times (72, 78 and 96 h after the beginning of their formation), for 1 minute, with Solutions containing microparticulate TMP (TMPm) and TMPn at concentrations of 1% and 3%, combined or not with 1100 ppm F. In addition, 1100 ppm F (F) solution and artificial saliva (CTL) were tested as positive and negative controls, respectively. After the last treatment, the composition of the extracellular matrix was analyzed in terms of protein and carbohydrate, and the pH and concentrations of F, calcium (Ca), phosphorus (P) and P of the TMP of the biomass and biofilm fluid were determined. In another set of experiments, after the last treatment, the biofilms were exposed to a 20% sucrose solution, and the pH and inorganic components of the biofilms were evaluated as mentioned above. Protein and carbohydrate data were subjected to 1-way ANOVA, followed by the Student-Newman-Keuls test, while biofilm inorganic composition data were subjected to 2-way ANOVA, followed by the Fisher LSD test (p< 0 .05). Treatments with 3% nTMP combined with F led to significantly greater reductions in extracellular matrix carbohydrate concentrations, and significantly higher pH, compared to all other groups. In addition, 3% nTMP without F led to significantly higher P concentrations compared to all other groups before sucrose exposure. It is concluded that TMPn affected the composition of the extracellular matrix, the pH of the analyzed biofilms, in addition to interfering with the inorganic components of the biofilms by increasing phosphorus levels in the biofilm fluid(AU)

Cardiovascular mortality in peritoneal dialysis: the impact of mineral disorders / Mortalidade cardiovascular em diálise peritoneal: o impacto dos distúrbios minerais

Abstract Introduction: Mineral and bone disorders (MBD) are associated with higher mortality in dialysis patients. The main guidelines related to the subject, Kidney Disease Outcomes Quality Initiative (KDOQI) and Kidney Disease: Improving Global Outcomes (KDIGO), were elaborated based on published information from hemodialysis participants. The aim of our study was to evaluate the impact of calcium (Ca), phosphorus (P), and parathyroid hormone (PTH) (according to guideline ranges from KDOQI and KDIGO) on the cardiovascular mortality of peritoneal dialysis (PD) patients. Methods: We used the BRAZPDII database, an observational multi-centric prospective study, which assessed participants on PD between December 2004 and January 2011. Amongst 9,905 participants included in this database, we analyzed 4424 participants who were on PD for at least 6 months. The appropriate confounding variables were entered into the model. Serum levels of Ca, P, and PTH were the variables of interest for the purposes of the current study. Results: We found a significant association between high P serum levels, categorized by KDOQI and KDIGO (P above 5.5 mg/dL), and cardiovascular survival (p < 0.01). Likewise, a compelling association was found between lower levels of PTH, categorized by guidelines (KDOQI and KDIGO - PTH less than 150 pg/mL, p < 0.01), and cardiovascular survival. Conclusion: In conclusion, levels of P above and PTH below the values proposed by KDOQI and KDIGO were associated with cardiovascular mortality in PD patients.

Resumo Introdução: Os distúrbios minerais e ósseos (DMO) estão associados a maior mortalidade em pacientes de diálise. As principais diretrizes relacionadas ao assunto, Kidney Disease Outcomes Quality Initiative (KDOQI) e Kidney Disease: Improving Global Outcomes (KDIGO) foram elaboradas com base em informações publicadas de pacientes em hemodiálise. O objetivo do nosso estudo foi avaliar o impacto do cálcio (Ca), fósforo (P) e paratormônio (PTH) (de acordo com as faixas propostas pelas diretrizes do KDOQI e KDIGO) na mortalidade cardiovascular de pacientes em diálise peritoneal (DP). Métodos: Utilizamos o banco de dados BRAZPDII, um estudo prospectivo observacional multicêntrico, que avaliou participantes de DP entre dezembro de 2004 e janeiro de 2011. Entre os 9.905 participantes incluídos neste banco de dados, analisamos 4.424 que estavam em DP há pelo menos 6 meses. As variáveis de confusão apropriadas foram inseridas no modelo. Os níveis séricos de Ca, P e PTH foram as variáveis de interesse para os fins do presente estudo. Resultados: Encontramos uma associação significativa entre níveis séricos de P elevados, categorizados por KDOQI e KDIGO (P acima de 5,5 mg/dL), e sobrevivência cardiovascular (p < 0,01). Da mesma forma, foi encontrada uma associação convincente entre níveis mais baixos de PTH, categorizados por diretrizes (KDOQI e KDIGO - PTH inferior a 150 pg/mL, p < 0,01), e sobrevivência cardiovascular. Conclusão: Em conclusão, níveis de P acima e PTH abaixo dos valores propostos por KDOQI e KDIGO foram associados à mortalidade cardiovascular em pacientes de DP.

Síntese e caracterização de ciclotrifosfato de sódio contendo cálcio e seu efeito na prevenção da erosão do esmalte in vitro / Synthesis and characterization of calcium-containing sodium cyclotriphosphate and its effect on preventing enamel erosion in vitro

O objetivo do presente estudo foi sintetizar e caracterizar ciclotrifosfato de sódio (NaTMP) contendo cálcio, e verificar seu efeito utilizando modelo de lesões iniciais de erosão do esmalte. Os ciclotrifosfatos contendo cálcio (CaNaTMP) foram sintetizados utilizando coluna para cromatografia e adição de sobrenadante de solução contendo hidróxido de cálcio e analisados por meio de microscopia eletrônica de varredura e espectroscopia de raios-X por dispersão de energia. Para determinar o efeito sobre lesões erosivas iniciais, blocos de esmalte bovino sadios (n=96) foram selecionados por dureza de superfície inicial e divididos em 8 grupos experimentais (12 blocos/grupo): controle (água deionizada), 0,24% NaF (1100 ppm F), 0,25%, 0,5% e 1% de NaTMP e CaNaTMP nas mesmas concentrações. Os blocos de esmalte foram imersos em 4 mL das soluções experimentais durante 2 minutos, seguidos por 4 desafios erosivos (ácido cítrico, 0,75%, pH 3,5, por 1 minuto, sob agitação). A porcentagem de perda da dureza de superfície (%SH) foi calculada após cada desafio ácido. Os dados foram submetidos à análise de variância de medidas repetidas a dois critérios, seguida pelo teste de Tukey (p< 0,05). O processo de síntese levou a substituição de átomos de Na por átomos de Ca e as partículas apresentaram tamanhos homogêneos. As soluções contendo 0,25%, 0,5% e 1% CaNaTMP apresentaram menor %SH quando comparadas as suas contrapartes sem cálcio (p< 0,001), após os quatro desafios erosivos. Quando comparado a solução contendo 1100 ppm F, as soluções 0,5% e 1% CaNaTMP promoveram redução na perda de dureza (p< 0,001). Concluiu-se que soluções contendo CaNaTMP promoveram efeitos protetores superiores em comparação ao grupo 1100 ppm F sobre lesões iniciais do esmalte(AU)

The objective of the present study was to synthesize and characterize sodium cyclotriphosphate (NaTMP) containing calcium and verify its effect using an initial enamel erosion model. Cyclotriphosphate containing calcium (CaNaTMP) was synthesized using column chromatography, and addition of a solution with calcio hydroxide supernatant and analyzed by scanning electron microscopy and energydispersive X-ray spectroscopy. To determine the effect on enamel initial erosion, sound bovine enamel blocks (n=96) were selected by initial surface hardness and divided into to 8 experimental groups (12 blocks/group): control (deionized water), 0.24% NaF (1100 ppm F), 0.25%, 0.5% and 1% NaTMP and CaNaTMP at the same concentrations. The enamel blocks were immersed in 4 mL of the experimental solutions for 2 minutes followed by 4 erosive challenges (citric acid, 0.75%, pH 3.5, for 1 minute, under stirring). The percentage of surface hardness variation (%SH) was calculated after each acid challenge. Data were subjected to two-way repeated measures analysis of variance, followed by Tukey's test (p< 0.05). The synthesis process led to the replacement atoms of Na by atoms of Ca with particles having, homogeneous sizes. The solutions containing 0.25%, 0.5% and 1% CaNaTMP promoted lower %SH when compared to their counterparts without calcium (p< 0.001), after the four erosive challenges. When compared to the solution containing 1100 ppm F, the 0.5% and 1% CaNaTMP solutions were superior in reducing hardness loss (p< 0.001). It was concluded that solutions containing CaNaTMP led to superior protective effects compared to the 1100 ppm F group on initial enamel erosion(AU)

Avaliação da atividade antimicrobiana de biomateriais nanocompósitos de poliamida 6 com nanopartículas de trimetafosfato decoradas com nanopartícula de prata / Evaluation of the antimicrobial activity of polyamide 6 nanocomposite biomaterials with trimetaphosphate nanoparticles decorated with silver nanoparticles

O uso de novos materiais nanocompósitos para fabricação de dispositivos protéticos, matrizes para preenchimento de defeitos ósseos, proteção do tecido pulpar de dentes e túbulos dentinários expostos pode colaborar significativamente na qualidade de vida da população. Objetivo: Realizar o processamento da matriz polimérica de poliamida-6 (P6) impregnada com nanopartículas de trimetafosfato (TMP) e nanopartícula de prata (AgNP), avaliar a atividade antimicrobiana contra Streptococcus mutans e Candida albicans e a liberação de TMP e Ag+ . Métodos: Foi determinado a concentração inibitória mínima (CIM) da AgNP com ou sem a presença da NH3 para S. mutans e C. albicans. Em seguida, realizado a síntese e caracterização dos nanocompósios (P6, P6-2,5, 5 e 10%TMP associado ou não a AgNP), quantificação das unidades formadoras de colônia (UFC), determinação do halo de inibição e quantificação de TMP e Ag+ liberados durante 1, 2, 3, 4, 5, 10, 12, 14, 16, 18, 20 e 24 horas em água deionizada. Os dados foram submetidos à análise de variância bidirecional, seguida do teste de Fisher LSD (p< 0,05). Resultados: A CIM para C. albicans foi de 9,40 mg/mL com ou sem a presença da NH3 e para o S. mutans foi de 601,9 mg/mL com NH3 e 300,9 mg/mL sem NH3. Nos testes de caracterização foi possível incorporar a P6 com TMP sem alterar suas propriedades. A maior quantidade de Ag+ liberada ocorreu nas primeiras três hora para todos os grupos decorados com AgNP. Houve liberação de TMP nas primeira três horas para os grupos P6-5%TMP e P6-10%TMP e para as demais membranas não foram detectadas liberações. No ensaio de difusão em ágar os halos formados para C. albicans e S. mutans mostraram ação da AgNP para ambos os microrganismos. Os grupos P6-Ag2,5%TMP e P6-Ag-5%TMP com AgNP apresentam maior redução de UFC para S. mutans quando comparado aos demais grupos, com maior redução no tempo de 18 horas. Para C. albicans todos os grupos apresentaram redução na UFC quando comparado ao controle, sem diferença estatística entre os mesmo. Conclusão: Foi possível desenvolver um matriz polimérica de P6 impregnada com TMP e AgNP com ação antimicrobiana contra os microrganismos testados(AU)

The use of new nanocomposite materials for the manufacture of prosthetic devices, matrices for filling bone defects, protection of the pulp tissue of exposed teeth and dentinal tubules can significantly contribute to the quality of life of the population. Objective: To perform the processing of the polymeric matrix of polyamide. 6 (P6) impregnated with trimetaphosphate nanoparticles (TMP) and silver nanoparticles (AgNP), evaluate the antimicrobial activity against Streptococcus mutans and Candida albicans and the release of TMP and Ag +. Methods: The minimum inhibitory concentration (MIC) of AgNP was determined with or without the presence of NH3 for S. mutans and C. albicans. Then, the synthesis and characterization of the nanocomposites (P6, P6-2.5, 5 and 10% TMP associated or not with AgNP), quantification of colony forming units (CFU), determination of the inhibition halo and quantification of TMP and Ag + released during 1, 2, 3, 4, 5, 10, 12, 14, 16, 18, 20 and 24 hours in deionized water. The data were submitted to bidirectional analysis of variance, followed by the Fisher LSD test (p < 0.05). Results: The MIC for C. albicans was 9.40 mg / mL with or without the presence of NH3 and for S. mutans it was 601.9 mg / mL with NH3 and 300.9 mg / mL without NH3. In the characterization tests it was possible to incorporate the P6 with TMP without changing its properties. The highest amount of Ag + released occurred in the first three hours for all groups decorated with AgNP. There was TMP release in the first three hours for the P6-5% TMP and P6-10% TMP groups and for the other membranes, no releases were detected. In the agar diffusion assay, halos formed for C. albicans and S. mutans showed AgNP action for both microorganisms. The P6-Ag-2.5% TMP and P6-Ag-5% TMP groups with AgNP show a greater reduction in CFU for S. mutans when compared to the other groups, with a greater reduction in the time of 18 hours. For C. albicans, all groups showed a reduction in CFU when compared to the control, with no statistical difference between them. Conclusion: It was possible to develop a polymeric matrix of P6 impregnated with TMP and AgNP with antimicrobial action against the microorganisms tested(AU)

Mechanical properties and surface roughness of polymer-based materials containing DCPD particles

Abstract The purpose of this study was to synthesize dicalcium phosphate dihydrate (DCPD) particles functionalized with triethylene glycol dimethacrylate (TEGDMA) through different routes by varying the receptor solution: ammonium phosphate (AP groups) or calcium nitrate (CN groups) and the moment in which TEGDMA was incorporated: ab initio (ab) or at the end of dripping the solution (ap). Two syntheses were performed without adding TEGDMA (nf). The particles were characterized by X-ray diffractometry, true density (using a helium pycnometer), surface area, and scanning electron microscopy. A 20 vol% of DCPD particles from the D, E, and F groups was added to the resin matrix to determine the degree of conversion (DC), biaxial flexural strength (BFS), the flexural modulus (FM), and surface roughness after an abrasive challenge (RA). A group with silanized barium glass particles was tested as a control. The data were submitted to ANOVA/Tukey's test (DC, BFS, and RA), and the Kruskal-Wallis test (FM) (alpha = 0.05). BFS values varied between 83 and 142 MPa, and the CN_ab group presented a similar value (123 MPa) to the control group. FM values varied between 3.6 and 8.7 GPa (CN_ab and CN_nf groups, respectively), with a significant difference found only between these groups. RA did not result in significant differences. The use of calcium nitrate solution as a receptor, together with ab initio functionalization formed particles with larger surface areas. Higher BFS values were observed for the material containing DCPD particles with a higher surface area. In general, the DC, FM, and RA values were not affected by the variables studied.

Efeito de vernizes fluoretados suplementados com nanopartículas de trimetafosfato de sódio sobre o desgaste dental erosivo in vitro e in situ / Effect of fluoride varnishes supplemented with nanosized Sodium Trimetaphosphate on enamel erosive wear in vitro and in situ

O presente estudo avaliou o efeito de vernizes fluoretados suplementados com nanopartículas de Trimetafosfato de Sódio (TMP) sobre o desgaste erosivo do esmalte dental bovino, em protocolos in vitro e in situ. Para a 1ª fase, blocos de esmalte dental bovino (n=100) foram selecionados por meio de dureza de superfície (DS) e aleatoriamente divididos em 5 grupos experimentais (n=20/grupo), de acordo com os vernizes testados: (a) Placebo (Pla - sem F ou TMP), (b) 5% NaF, (c) 5% NaF + 5% TMP microparticulado (5% Micro), (d) 5% NaF + 2,5% TMP nanoparticulado (2,5% Nano), (e) 5% NaF + 5% TMP nanoparticulado (5% Nano). Os blocos receberam uma única aplicação dos vernizes e foram imersos em saliva artificial por 6 h. Em seguida, os vernizes foram removidos e todos os blocos, submetidos a 4 desafios erosivos diários durante 5 dias (ERO, imersão em ácido cítrico 0,05 M, pH 3,2, 90 s/ciclo, sob agitação). Após ERO, metade dos blocos foi submetida a abrasão por escovação (15 s/ciclo) com dentifrício placebo (ERO+ABR). Os blocos foram analisados por perfilometria, dureza de superfície (DS) e dureza em secção longitudinal (ΔKHN). Os dados foram submetidos a ANOVA a dois critérios e Teste de Fisher LSD (p< 0,05). O desgaste do esmalte foi significativamente menor para ERO comparado a ERO+ABR para todos os vernizes testados (p< 0,001), seguindo o padrão 5% Nano < 5% Micro < 5% NaF < 2,5% Nano < Pla (ERO e ERO+ABR). A maior perda de DS foi observada para o Pla e a menor para 5% NaF (ERO) e 2,5% Nano (ERO+ABR), sem diferenças significativas entre 2,5% Nano, 5% NaF e 5% Micro. Os maiores valores de ΔKHN foram observados para 5% Micro e 5% Nano a 5-30 µm, com diferenças menos acentuadas entre os grupos a 30-70 µm (ERO e ERO+ABR). Para a 2ª fase, blocos de esmalte bovino (n=224) foram selecionados por DS e distribuídos aleatoriamente entre os grupos: (a) Placebo (Pla - sem F ou TMP), (b) 5% NaF, (c) 5% NaF + 5% TMP microparticulado (5% Micro), e (d) 5% NaF + 5% TMP nanoparticulado (5% Nano). Os blocos foram inseridos em dispositivos acrílicos palatinos (n=4/dispositivo), e tratados com os vernizes uma única vez, permanecendo na cavidade bucal dos voluntários (n=14) por 6 h. Em seguida, os vernizes foram removidos e os blocos, submetidos à ERO (imersão ex vivo em ácido cítrico 0,05 M, pH 3,2, 90 s, 4x/dia), enquanto dois blocos foram adicionalmente submetidos a abrasão por escovação com dentifrício fluoretado (ERO+ABR), totalizando 5 dias em cada etapa experimental, seguindo um protocolo duplo-cego e cruzado. As análises dos blocos e dos dados foram idênticas às da 1ª fase. Os valores do desgaste seguiram um padrão similar em ambas as condições experimentais (ERO ou ERO+ABR), com 5% Nano < 5% Micro < 5% NaF < Pla. Um padrão similar foi observado para dureza em secção longitudinal (ΔKHN), apesar de não serem verificadas diferenças significativas entre 5% Micro×5% Nano (5-30 µm). Quanto à perda de DS, o maior valor foi observado para Pla e o menor para 5% Nano (ERO ou ERO+ABR), sem diferenças significativas entre Pla×5% NaF (ERO), 5% NaF×5% Micro (ERO+ABR), e 5% Micro×5% Nano (ERO+ABR). Diante dos resultados, conclui-se que a adição de TMP a vernizes fluoretados melhorou significativamente a proteção contra o desgaste erosivo do esmalte in vitro e in situ. O uso de 5% de TMP em escala nanométrica aumentou ainda mais esses efeitos(AU)

The present study evaluated the effect of fluoride (F) varnishes supplemented with sodium trimetaphosphate (TMP) nanoparticles on erosive tooth wear, using in vitro and in situ protocols. For the first phase, bovine enamel blocks (n=100) were selected by surface hardness (SH) and randomly divided into 5 experimental groups (n=20/group), according to the varnishes tested: (a) Placebo (Pla - without F or TMP), (b) 5% NaF, (c) 5% NaF + 5% micrometric TMP (5% Micro), (d) 5% NaF + 2.5% nano-sized TMP (2.5% Nano), (e) 5% NaF + 5% nano-sized TMP (5% Nano). Blocks received a single varnish application, and were immersed in artificial saliva for 6 h. Varnishes were then removed and all blocks, subjected to 4 daily erosive challenges during for 5 days (ERO, immersion in 0.05 M citric acid, pH 3.2, 90 s/cycle, under agitation). After ERO, half of the blocks were subjected to abrasion by brushing (15 s/cycle) with placebo dentifrice (ERO+ABR). Blocks were analyzed by profilometry, surface hardness (SH) and cross-sectional hardness (ΔKHN). The data were submitted to 2-way ANOVA and Fisher's LSD test (p< 0.05). Enamel wear was significantly lower for ERO compared to ERO+ABR for all varnishes tested (p< 0.001), following the pattern 5% Nano < 5% Micro < 5% NaF < 2.5% Nano < Pla (ERO and ERO+ABR). The highest SH loss was observed for Pla, and the lowest for 5% NaF (ERO) and 2.5% Nano (ERO+ABR), without significant differences between 2.5% Nano, 5% NaF and 5% Micro. The highest values of ΔKHN were observed for 5% Micro and 5% Nano at 5-30 µm, with less marked differences between the groups at 30-70 µm (ERO and ERO+ABR). In the second phase, bovine enamel blocks (n=224) were selected by SH and randomly distributed among the groups: (a) Placebo (Pla - without F or TMP), (b) 5% NaF, (c) 5% NaF + 5% micrometric TMP (5% Micro), and (d) 5% NaF + 5% nano-sized TMP (5% Nano). The blocks were inserted in acrylic palatal devices (n=4/device), and treated with the varnishes only once, remaining in the oral cavity of the volunteers (n=14) for 6 h. Then, the varnishes were removed and the blocks, subjected to ERO (ex vivo immersion in 0.05 M citric acid, pH 3.2, 90 s, 4x/ day), while two blocks were additionally subjected to abrasion by brushing with fluoride dentifrice (ERO+ABR), totaling 5 days in each experimental stage, following a double-blind, crossover protocol. The blocks and the data were analyzed as described for the first phase. The wear values followed a similar pattern under both experimental conditions (ERO or ERO+ABR), with 5% Nano < 5% Micro < 5% NaF < Pla. A similar pattern was observed for hardness in depth (ΔKHN), although no significant differences were found between 5% Micro×5% Nano (5-30 µm). As for SH loss, the highest value was observed for Pla, and the lowest for 5% Nano (ERO or ERO+ABR), without significant differences between Pla×5% NaF (ERO), 5% NaF×5% Micro (ERO+ABR), and 5% Micro×5% Nano (ERO + ABR). In view of the results, it was concluded that the addition of TMP to fluoride varnishes significantly improved protection against erosive enamel wear in vitro and in situ. The use of 5% nano-sized TMP further increased these effects(AU)

Efeito de dentifrícios com reduzida concentração de fluoreto contendo trimetafosfato de sódio e polióis na erosão inicial do esmalte / Effect of low-fluoride toothpaste containing sodium trimetaphosphate and polyols on initial enamel erosion

Este estudo in vitro avaliou o efeito de dentifrícios contendo fluoreto (F), trimetafosfato de sódio (TMP) e/ou xilitol e eritritol (XE) em inibir ou reparar lesão erosiva inicial do esmalte. Blocos de esmalte bovino (n=120) foram selecionados por dureza de superfície (SH) inicial e divididos em 5 grupos compostos por dentifrícios (24 blocos/grupo): Placebo (sem F, TMP e XE); 1100 ppm F; 16% xilitol + 4% eritritol (XE); 200 ppm F + 0,2% TMP (200 ppm F/TMP); e 200 ppm F + 0,2% TMP + 16% xilitol + 4% eritritol (200 ppm F/TMP/XE). Para a análise do efeito protetor, blocos hígidos (n=60) foram imersos 1x/2 minutos em suspensão de dentifrícios/saliva humana. Em seguida, os blocos foram submetidos a 4 desafios erosivos com ácido cítrico (0,75%, pH 3,5) de 1 minuto cada, sob agitação. A seguir, a SH foi determinada pós-tratamento (t) e após o 1º, 2º, 3º e 4º desafios ácidos erosivos (d) para o cálculo da porcentagem de variação da SH (%SH). Para a análise do efeito reparador, esmalte previamente erodido (n=60) foi tratado e submetido aos mesmos desafios erosivos descritos anteriormente. A %SH de recuperação (R) e %SHt foram calculadas, bem como, a diferença entre a %SHR e %SHd obtendo-se o Δ%SH para cada desafio. Experimento adicional foi realizado para análise da deposição de precipitados por Microscopia Eletrônica de Varredura (MEV) em esmalte hígido e erodido. Os dados foram submetidos à análise de variância de medidas repetidas a dois critérios, seguida pelo teste de Student-Newman-Keuls (p<0,05). Os resultados mostraram que o maior efeito protetor e reparador foi produzido pelo dentifrício 200 ppm F/TMP/XE quando comparado aos demais grupos (p<0,001). Os grupos 1100 ppm F e 200 ppm F/TMP apresentaram similar efeito protetor para o 1º, 2º e 3º desafios (p>0,05), e menor quando comparados ao XE (p<0,001). O efeito protetor e reparador foi: XE>200 ppm F/TMP>1100 ppm F>Placebo (p<0,001). Na MEV observou-se deposição de precipitado no esmalte para todos os grupos, formando uma camada mais espessa e homogênea nos grupos contendo XE e/ou TMP. Concluiu-se que dentifrício contendo 200 ppm F, TMP e polióis apresenta efeito protetor e reparador superior quando comparado a um dentifrício 1100 ppm F em lesões erosivas iniciais no esmalte(AU)

This in vitro study evaluated the effect of toothpaste containing fluoride (F), sodium trimetaphosphate (TMP) and/or xylitol and erythritol (XE) in inhibit or repair initial enamel erosion lesions. Bovine enamel blocks (n=120) were selected by initial surface hardness (SH) and divided into 5 groups of toothpastes (n=24 blocks/group): Placebo (no F, TMP or XE); 1100 ppm F; 16% xylitol + 4% erythritol (XE); 200 ppm F + 0.2% TMP (200 ppm F/TMP); and 200 ppm F + 0.2% TMP + 16% xylitol + 4% erythritol (200 ppm F/TMP/XE). For the analysis of the protective effect, sound blocks (n=60) were immersed in toothpaste slurry in human saliva once for 2 minutes. Hereafter, the blocks were submitted to 4 erosive challenges in citric acid (0.75%, pH 3.5) by 1 minute, under stirring. Then, the SH was determined after treatment (t) and after the 1st, 2nd, 3rd and 4th erosive acid challenges (d) to calculate the percentage of change of the SH (%SH). For the analysis of the repair effect, eroded enamel (n=60) were treated and submitted to erosive challenges as describe previously. The recovery (R) of %SH and %SHt were calculated, as well as the difference between the %SHR and %SHd obtaining the Δ%SH for each challenge. Additional experimental was performed to analysis the deposition of precipitates by Scanning Electronic Microscopy (SEM) on sound and eroded enamel. Variables were submitted to two-way repeated measures analysis of variance followed by StudentNewman-Keuls test (p<0.05). The results showed that the highest protective and repair effect was produced by the 200 ppm F/TMP/XE toothpaste when compared to the other groups (p<0.001). The 1100 ppm F and 200 ppm F/TMP groups had similar protective effect for the 1st, 2nd and 3rd challenges (p>0.05), and lower when compared to XE (p<0.001). The protective and repair effect was: XE>200 ppm F/TMP>1100 ppm F>Placebo (p<0.001). There were deposition of precipitates on enamel for all groups, with a thicker layer and homogeneous for XE and/or TMP groups. It was concluded that toothpaste containing 200 ppm F, TMP and polyols has superior protective and repair effect when compared to 1100 ppm F toothpaste in initial enamel erosive lesions(AU)

Surface and mechanical properties of adhesives with calcium phosphates challenged to different storage media

Aim: To evaluate the behavior of experimental dental adhesives with hydroxyapatite (HAp), alpha-tricalcium phosphate (α-TCP) or octacalcium phosphate (OCP) after storing them in three different media: dry storage, distilled water, or lactic acid. Methods: An experimental adhesive resin was formulated with bisphenol A glycol dimethacrylate, 2-hydroxyethyl methacrylate, and photoiniciator/co-initiator system. HAp(GHAp), α-TCP (Gα-TCP), or OCP (GOCP) were added to the adhesive resin at 2 wt.%, and one group remained without calcium phosphates to be used as a control (GCtrl). The adhesives were evaluated for surface roughness, scanning electron microscopy (SEM), and ultimate tensile strength (UTS) after storing in distilled water (pH=5.8), lactic acid (pH=4) or dry medium. Results: The initial surface roughness was not different among groups (p>0.05). GHAp showed increased values after immersion in water (p<0.05) or lactic acid (p<0.05). SEM analysis showed a surface variation of the filled adhesives, mainly for Gα-TCP and GHAp. GHApshowed the highest UTS in dry medium (p<0.05), and its value decreased after lactic acid storage (p<0.05). Conclusions: The findings of this study showed that HAp, OCP, and α-TCP affected the physical behavior of the experimental adhesive resins in different ways. HAp was the calcium phosphate that most adversely affected the surface roughness and the mechanical property of the material, mainly when exposed to an acid medium

Stocks and Distribution of Soil Carbon, Nitrogen, Phosphorus and Sulfur in an Integrated Crop-Livestock System Treated with Phosphates

Abstract Conservation agriculture practices can contribute to changes in soil nutrient dynamics over time. This experiment evaluated the changes in total stocks and distribution of carbon, nitrogen, phosphorus and sulfur concentrations in soil, during 60 months, in an integrated crop-livestock system (ICLS) due to anticipated fertilization of sources and doses phosphates applied in soil surface. The experiment was conducted over a period of five years, under Typic Dystrudept, using a randomized block design, in an incomplete factorial scheme (3×3+1), with four replications. Treatments consisted of three sources of P [triple superphosphate (TSP), rock phosphate - Arad (RP) and magnesium thermophosphate (MTP)], along with four doses of P (0, 60, 120 and 180 kg ha-1 P2O5 total). Samples of soil were collected in 0-5, 5-10, 10-15, 15-20 and 20-30 cm layers at 24, 36, 48 and 60 months after beggining of experiment where the following chemical attributes were evaluated: (i) total organic carbon (TOC); (ii) total nitrogen Kjeldahl (TNK); (iii) available P by ion exchange resin method (P-IER); and (iv) available S-SO4 2-. The ICLS conditions provided increased total stocks and concentrations of TOC, TNK, P-IER and S-SO4 2- over time. The applications of different phosphates had no influence on soil TOC concentrations during the five years of experimentation. The concentrations of TNK, P-IER and S-SO4 2- showed an increase in different layers of soil, with the application of sources and doses of P. The P fertilization practice that was anticipated can consist of an efficient management of soil fertility, using properly managed conservation systems.

An in Vitro Evaluation of Remineralizing Capacity of Self-Assembling Peptide (SAP) P11-4 and Casein Phosphopeptides-Amorphous Calcium Phosphate (CPP-ACP) on Artificial Enamel

Objective: To determine and compare the remineralizing capacity of self-assembling peptide (SAP) P11-4 and casein phosphopeptides­amorphous calcium phosphate (CPP-ACP) on enamel. Material and Methods: Enamel samples were divided into 2 groups. Group I was treated with Self­assembling peptide (SAP) P11-4 and group II with casein phosphopeptides-amorphous calcium phosphate (CPP-ACP). In both groups, remineralizing capacity was assessed at baseline, 2 weeks, 6 weeks and 12 weeks. Student's t- test and ANOVA were applied, with the significance level set at 5%. Results: The mean calcium weight % was evaluated at baseline, 2 weeks, 6 weeks and 12 weeks. In Group I, there was increase in mean value (62.12 ± 1.24) from baseline to 12 weeks (67.36 ± 2.14). However, there was decrease in phosphate weight % from 37.16 ± 2.52 at baseline to 35.72 ± 2.11 at 12 weeks. In Group II, mean calcium weight % was 64.18 ± 1.52 at baseline, which ultimately increased to 66.01 ± 2.03 at 12 weeks. Phosphate weight % showed reduction from 37.34 ± 2.23 at baseline to 35.04 ± 2.02 at 12 weeks. Ca/P ratio showed significant improvement. There was significant difference in Ca/P ratio at 2 weeks, 6 weeks and 12 weeks in both groups (p<0.05). Conclusion: Self-assembling peptide (SAP) P11-4 found to be more effective and efficient as compared to casein phosphopeptides­amorphous calcium phosphate (CPP-ACP).

Comparative Evaluation of Remineralizing Potential of a Paste Containing Bioactive Glass and a Topical Cream Containing Casein Phosphopeptide-Amorphous Calcium Phosphate: An in Vitro Study

Objective: To evaluate and compare the remineralization potential of a dentifrice containing bioactive glass and a topical cream containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) in remineralizing artificial carious lesion on enamel. Material and Methods: Forty-five freshly extracted human permanent premolar teeth were selected. Samples were divided into three groups: GI - regular tooth paste without specific remineralizing agent; GII - tooth paste containing calcium sodium-phosphosilicate (novamin) and GIII - topical cream containing casein phosphopeptide-amorphous calcium phosphate. All the sound enamel samples were viewed under scanning electron microscope (SEM) to assess the topographical pictures of enamel surface and energy dispersing x-ray analysis (EDAX) was done to estimate quantitatively the amounts of mineral (calcium and phosphorous). The mineral content of calcium and phosphorus after demineralization in each group was noted. The samples were then subjected to SEM and EDAX. Results: GI does not show any increase in the calcium and phosphorus after applying toothpaste without any remineralizing agent but GII and GIII showed a net increase in calcium and phosphorous values after applying concern-remineralizing agents. Inter group comparison showed GIII yield higher net calcium and phosphorous values than GII. Conclusion: Two remineralizing agents showed remineralization potential on enamel surfaces. Casein phosphopeptide-amorphous calcium phosphate showed better remineralizing potential than calcium sodium phosphosilicate. Hence CPP-ACP can be considered as the material of choice in remineralizing early enamel carious lesions.

The Ability of Biodentine™ of Guided Tissue Remineralization (GTR): Analysis Using SEM, EDX and TEM

Objective: To analyze the Biodentine™ capability in guided tissue remineralization. Material and Methods: Four premolar with two cavities per tooth of 3 mm depth were demineralized with EDTA 17% in shaking incubator at 37°C temperature. After 7 days, the sample were washed with aquabidest then were soaked in 20 ml NaCl 1 M (pH 7.0) at 25°C temperature for 8 hours. The samples were divided into two groups: G1: The control group (cavity directly restored with composite resin); G2: Biodentine™ group (cavity with Biodentine™ as a base then restored with composite resin). All samples were stored in shaking incubator under PBS solution at 37°C temperature. SEM, EDX and TEM analysis were performed on the 7th and 14th day. Results: The 14th day Biodentine group had the best SEM remineralization feature with irregular dentine tubular features covered by density of mass. In the EDX analysis, the concentration of calcium ion of the Biodentine group was higher than the control group on the 7th day analysis (Biodentin™ 10.2167 and control 1.9667) and on the 14th day analysis (Biodentine™ 29.833 and Control 22.080). The Biodentine™ group and control group of the 7th and 14th day experienced significant increases in calcium ion concentration while the concentration of phosphate ion in the Biodentine™ and control group had a much lower value of calcium either on the 7th or 14th day. The TEM analysis of Biodentine™ group showed more intrafibrillar remineralization than the control group. The feature of intrafibrillar dentin remineralization is analyzed by looking at the density of black dots in collagen. Conclusion: Biodentine™ is able to trigger the process of remineralization by guided tissue remineralization.

Patent analysis for calcium phosphate bone cements / 中国组织工程研究

BACKGROUND: Calcium phosphate bone cement exhibits great commercial potential as bone filling materials in the field of clinical biomedical engineering; however, due to some existing technical and theoretical challenges, its wide spread application is hindered. It is therefore necessary to search existing patents to explore various potential improvements in modification of calcium phosphate bone cement. OBJECTIVE: To analyze the patent information of calcium phosphate bone cement for better understanding of the development of the calcium phosphate bone cement technology, and for early warning of patent infringement.METHODS: Based on the manual screening of Incopat patent database, we analyzed 2 711 patent documents from four aspects — the application trend, patent layout, competitor analysis, and efficacy matrix. In combination with technology development and industrialization, this paper also shows some important Chinese patents selectively. RESULTS AND CONCLUSION: The United States is in the leading position in the calcium phosphate bone cement field, while this technology is developing rapidly in China. Various components and methods are developed for modifying calcium phosphate bone cement, which are the focus of patent development and layout. Although some of the fundamental patents have expired, patent infringement risks need to be tested and mitigated for the development and industrialization by Chinese enterprises as there are some important patents in China arranged by foreign companies. At the same time, Chinese patent holders need to master international patent layout and develop their intellectual properties for the future international marketplace.

Three-dimensional printing beta-tricalcium phosphate scaffold loaded with icariin particles for repairing osteonecrosis of the femoral head in rabbits / 中国组织工程研究

BACKGROUND: Preliminary study has prepared three-dimensional printing β-tricalcium phosphate scaffold loaded with icariin. OBJECTIVE: To investigate the role of three-dimensional printing β-tricalcium phosphate scaffold loaded with icariin in the repair of rabbit models of osteonecrosis of the femoral head. METHODS: New Zealand white rabbits (provided by Qinglongshan Laboratory Animal Center of Nanjing) were selected to establish the steroid-induced osteonecrosis of the femoral head. The 27 model rabbits underwent core decompression and debridement, were randomly divided into three groups, and then implanted with autologous bone, β-tricalcium phosphate scaffold, three-dimensional printing β-tricalcium phosphate scaffold loaded with icariin (composite scaffold group) , respectively. The micro-CT scanning and pathological observation were performed at 4, 8, and 12 weeks after implantation. RESULTS AND CONCLUSION: (1) Micro-CT showed that at 4 weeks after implantation, trabecular bone was observed around and in implants in each group. In the autologous bone group, there were a large number of trabecular bones in the grafting area at 8 weeks, and the trabecular bone structure was dense at 12 weeks after implantation. In the tricalcium phosphate and composite scaffold groups, the scaffolds were well integrated with the bone interface. At 4 weeks after implantation, there was a certain amount of trabecular bone surrounding the scaffold, and trabecular grew into the scaffold until 8 weeks in the composite scaffold group. At 4 weeks after implantation, few thin trabecular bone was visible, and extensive trabecular bone formation was observed around the scaffold at 8 weeks in the tricalcium phosphate group. (2) Hematoxylin-eosin staining results showed that there were many mature osteoblasts, and few cartilage matrix, newly born bones integrated well to the implants at 12 weeks in the autologous bone and tricalcium phosphate groups. In the composite scaffold group, there were many cartilage matrixes, and newly born bones integrated poorly to the implants. (3) Masson staining showed that at 12 weeks after implantation, the osteogenic capacity in the composite scaffold group was lower than that in the autologous bone group (P < 0.05) , but higher than that in the tricalcium phosphate group (P < 0.05) . (4) TRAP staining results at 12 weeks after implantation revealed that the amount of osteoclast in composite scaffold group was less than that in the tricalcium phosphate group (P < 0.05) , and was not significantly different from the autologous bone group (P> 0.05) . (5) Immunohistochemical staining at 12 weeks after implantation revealed that the positive rate of vascular endothelial growth factor in the composite scaffold group was higher than that in the tricalcium phosphate group (P < 0.05) , and lower than that in the autologous bone group (P < 0.05) . (6) In summary, three-dimensional printing β-tricalcium phosphate scaffold loaded with icariin implanted into the rabbit model of osteonecrosis of the femoral head can promote the proliferation and differentiation of osteoblasts, inhibit the viability of osteoclasts, promote the angiogenesis, and contribute to the repair of osteonecrosis of the femoral head in rabbits.

Calcium phosphate cement/fibrin glue composite loaded with recombinant human bone morphogenetic protein 2 promotes osteoporotic fracture healing / 中国组织工程研究

BACKGROUND: Bone morphogenetic protein 2 is a most widely studied and osteogenic-inducing bone morphogenetic protein. However, simple bone morphogenetic protein can be diluted by tissue fluid and decomposed by protease after implantation, so it is difficult to maintain sustained drug concentration or play an effective role in bone induction. OBJECTIVE: To observe the effect of repairing osteoporotic fracture through calcium phosphate cement/fibrin glue composite as the carrier of bone morphogenetic protein 2. METHODS: Fifty-four female Sprague-Dawley rats were selected to remove bilateral ovaries for making osteoporosis models. Three months later, the middle femoral fracture models were made, and then randomized into three groups, with 18 rats in each group. Kirschner wire fixation group was injected nothing. The fracture end was injected with 0.5 mL calcium phosphate cement/fibrin glue (composite group) or calcium phosphate cement/fibrin glue loaded with recombinant human bone morphogenetic protein 2 (loaded group) . At 4 and 12 weeks after fracture, X-ray examination, micro-CT examination, biomechanical three-point bending test and pathological observation were performed. RESULTS AND CONCLUSION: (1) The fracture healing score in the loaded group was higher than that in the other two groups (P < 0.05) . (2) The bone volume fraction, trabecular thickness and number of trabeculae at 4 and 12 weeks in the loaded group were higher than those in the other two groups (P < 0.05) , and the trabecular segregation was lower than that in the other two groups (P < 0.05) . (3) The maximum load and stiffness at 4 and 12 weeks in the loaded group were higher than those in the other two groups (P < 0.05) , and the elastic modulus at 4 weeks after fracture was higher than that in the other two groups (P < 0.05) . (4) Fibrocartilage callus was mainly seen at 4 weeks after fracture in the Kirschner wire fixation group, and the callus was reconstructed into lamellar bone at 12 weeks after fracture with less callus content. Obvious fibrocartilage callus appeared at 4 weeks after fracture in the composite and loaded groups, and the callus was reconstituted into a plate-like bone at 12 weeks. (5) These results imply that the calcium phosphate cement/fibrin glue composite loaded with recombinant human bone morphogenetic protein 2 can promote the healing of osteoporotic fracture and improve bone strength.