Effect of the secretome of mesenchymal stem cells overexpressing BMP-9 on osteoblast differentiation and bone repair.

The secretome present in the conditioned medium (CM) of mesenchymal stem cells (MSCs) is a promising tool to be used in therapies to promote bone regeneration. Considering the high osteogenic potential of the bone morphogenetic protein 9 (BMP-9), we hypothesized that the secretome of MSCs overexpressing BMP-9 (MSCsBMP-9 ) enhances the osteoblast differentiation of MSCs and the bone formation in calvarial defects. CM of either MSCsBMP-9 (CM-MSCsBMP-9 ) or MSCs without BMP-9 overexpression (CM-MSCsVPR ) were obtained at different periods. As the CM-MSCsBMP-9 generated after 1 h presented the highest BMP-9 concentration, CM-MSCsBMP-9 and CM-MSCsVPR were collected at this time point and used to culture MSCs and to be injected into mouse calvarial defects. The CM-MSCsBMP-9 enhanced the osteoblast differentiation of MSC by upregulating RUNX2, alkaline phosphatase (ALP) and osteopontin protein expression, and ALP activity, compared with CM-MSCsVPR . The CM-MSCsBMP-9 also enhanced the bone repair of mouse calvarial defects, increasing bone volume, bone volume/total volume, bone surface, and trabecular number compared with untreated defects and defects treated with CM-MSCsVPR or even with MSCsBMP-9 themselves. In conclusion, the potential of the MSCBMP-9 -secretome to induce osteoblast differentiation and bone formation shed lights on novel cell-free-based therapies to promote bone regeneration of challenging defects.

Effects of Modulation of the Hedgehog and Notch Signaling Pathways on Osteoblast Differentiation Induced by Titanium with Nanotopography.

BACKGROUND: The events of bone formation and osteoblast/titanium (Ti) interactions may be affected by Hedgehog and Notch signalling pathways. Herein, we investigated the effects of modulation of these signalling pathways on osteoblast differentiation caused by the nanostructured Ti (Ti-Nano) generated by H2SO4/H2O2. METHODS: Osteoblasts from newborn rat calvariae were cultured on Ti-Control and Ti-Nano in the presence of the Hedgehog agonist purmorphamine or antagonist cyclopamine and of the Notch antagonist N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) or agonist bexarotene. Osteoblast differentiation was evaluated by alkaline phosphatase activity and mineralization, and the expression of Hedgehog and Notch receptors was also evaluated. RESULTS: In general, purmorphamine and DAPT increased while cyclopamine and bexarotene decreased osteoblast differentiation and regulated the receptor expression on both Ti surfaces, with more prominent effects on Ti-Nano. The purmorphamine and DAPT combination exhibited synergistic effects on osteoblast differentiation that was more intense on Ti-Nano. CONCLUSION: Our results indicated that the Hedgehog and Notch signalling pathways drive osteoblast/Ti interactions more intensely on nanotopography. We also demonstrated that combining Hedgehog activation with Notch inhibition exhibits synergistic effects on osteoblast differentiation, especially on Ti-Nano. The uncovering of these cellular mechanisms contributes to create strategies to control the process of osseointegration based on the development of nanostructured surfaces.

Brazilian dentists' perception of dentin hypersensitivity management.

The aim of this study was to investigate how Brazilian dentists perceive and manage dentin hypersensitivity (DH) in their clinical routine. A 13-item questionnaire-based survey was developed and sent electronically to a convenience sample of dentists. The questionnaire assessed the personal and dental practice characteristics of the sample, the occurrence of DH in their daily clinical practice, and management strategies. The data were analyzed descriptively and together with the chi-square test (a = 0.05). A total of 353 responses were obtained from September 2017 to March 2018. Of all the respondents, 62% were females, 49.9% reported fewer than five years of dental practice, and 70.5% were self-identified as private practitioners. Most of the dentists reported an estimated frequency (30-60%) of patients with DH in their practice. The most frequently cited (91.79%) trigger of DH was air blast and/or scratching with a probe. The first-choice strategy to manage DH was a dentin desensitizer (48.16%). The number of years in clinical practice did not influence DH relapse frequency (p = 0.76) significantly, or consider DH treatment as a problem (p = 0.22). The present findings indicate that, regardless of clinical experience, dentists in Brazil still consider DH management a challenge in their daily dental practice. In addition, the results suggest that guidelines should be developed to disseminate the available knowledge regarding this condition in ways that may influence decision-making processes among practitioners.

Relationship between noncarious cervical lesions, cervical dentin hypersensitivity, gingival recession, and associated risk factors: A cross-sectional study.

OBJECTIVES: The aim of this study was to evaluate the risk factors associated with noncarious cervical lesions (NCCLs), cervical dentin hypersensitivity (CDH), and gingival recession (GR), besides the relationship among these conditions in a specific Brazilian sample population. METHODS: 185 patients who attended the "Ambulatory Program for Rehabilitation of Patients with Noncarious Cervical Lesions and Cervical Dentin Hypersensitivity" were evaluated, and 5180 teeth were analyzed. The subjects filled out a form and a calibrated examiner performed the clinical exams to determine the presence of NCCLs, CDH, and GR. NCCLs were classified according to their morphology and depth, CDH levels were evaluated according to air stimuli response, and GRs were categorized according to Miller's classification. The association of the risk factors with NCCLs, CDH, and GR was determined with the Mann-Whitney U test and multiple linear regression. For the correlations, the Spearman test was used with a 95%-confidence level. RESULTS: The NCCLs, CDH, and GR distributions within the study were 88.1%, 89.1%, and 59.4%, respectively. Maxillary premolars were the most affected by all three conditions. A positive correlation was found between age, NCCLs, and GR; between NCCLs and CDH; CDH and GR; GR and NCCLs. Age, gender, oral hygiene, gastroesophageal diseases, and occlusal trauma were significantly associated with the presence of all three conditions. CONCLUSIONS: The NCCLs and GR distributions increased with age; NCCLs, CDH, and GR had positive correlation; the lesions' depth and morphology contributed to high levels of sensitivity and severity of recessions; age, gender, gastric disease, and occlusal trauma were relevant factors for the occurrence of NCCLs, CDH, and GR. CLINICAL SIGNIFICANCE: The increasing distribution of NCCLs, CDH, and GR is closely associated with people's lifestyles. Thus, it is important for the clinicians to recognize the etiological factors and their most relevant associations to prevent and control such alterations, in order to improve the population's quality of life.

Critical analysis of fiber post surface treatment: a review / Análise crítica do tratamento de superfície de pinos de fibra: uma revisão

The surface treatment of fiber posts influence the bonding between composite resin cements and intraradicular retainers, being relevant to the prognostic of teeth without coronal structure. This study aimed to evaluate the different fiber post surface treatment protocols described on literature. The search strategy included a review of PubMed/MEDLINE database using fiber post associated with adhesion; bonding; surface treatment; as keywords. Papers not comprehending English language; assessment of post surface treatment; or testing of materials and their physicmechanical properties were excluded. Studies about glass and quartz fiber post surface treatment were considered for this literature review. Among the 190 articles included, silane agent was the material most used (60.52%) for the surface treatment of fiber posts, followed by application of alcoholic solutions (38.29%), and primer and/or adhesive systems (36.84%). Sandblasting of post surface was mentioned in (17.89%), but it affected the physical and mechanical properties. Hydrogen peroxide was mentioned only in 5.78% and it was shown to result on adequate exposure of the glass fibers without damaging them. It was concluded that a consensus for fiber post surface treatment still not exist in the current literature. Among the protocols described, the one using hydrogen peroxide followed by application of silane seems the most promising, since it allows increased bond strengths without fiber damage.

O processo de tratamento da superfície de pinos pré-fabricados de fibra influencia na união entre cimentos resinosos e esses retentores intra-radiculares, sendo relevante para o prognóstico do tratamento restaurador de dentes sem remanescente coronário. Este estudo objetivou avaliar diferentes protocolos de tratamentos de superfície para pinos de fibra descritos na literatura. Como metodologia, realizou levantamento bibliográfico na plataforma PubMed/MEDLINE, com a palavras-chave fiber post associada à adhesion; bonding; surface treatment. Excluíram-se artigos não redigidos em inglês; que não trataram a superfície do pino; e testes de propriedades físicas-mecânicas. Estudos que trataram a superfície de pinos de fibra de quartzo ou vidro foram incluídos. Dentre os 190 artigos incluídos nesta revisão, o agente silano foi o material mais utilizado (60.52%) para tratamento de superfície de pinos de fibra, seguido pela aplicação de álcool (38.29%), e sistema adesivo (36.84%). O jateamento do pino foi mencionado em 17.89%, mas esta técnica resultou em alteração das propriedades físicas e mecânicas. O peróxido de hidrogênio foi mencionado em 5.78% dos manuscritos, entretanto este tratamento permite a adequada exposição das fibras sem danificá-las. Concluiu-se que não consta na literatura protocolo padrão do tratamento da superfície de pinos de fibra. Dentre os protocolos descritos, o protocolo utilizando peróxido de hidrogênio seguido da aplicação do silano aparece como o mais promissor, pois permite resistência de união aumentada sem promover danos as fibras.

The effects of non carious cervical lesions - morphology, load type and restoration - on the biomechanical behavior of maxillary premolars: a finite element analysis / OS efeitos das lesões cervicais não cariosas ­ morfologia, tipo de carregamento e restauração - no comportamento biomecânico de pré-molares superiores: análise por elementos finitos

The aim of the present study was to analyze the effects of different types of non-carious cervical lesions (NCCLs) and their morphologies in premolars, restored (or not) with composite resin, on the application three occlusal loadings. The hypothesis was that differing NCCL morphologies, loading types and restoration with composite resin affect stress distribution patterns. A two-dimensional linear Finite Element Analyses (FEA) simulated a healthy tooth model (H) with dental structures including: dentin, pulp, enamel, periodontal ligament, cortical bone, and trabecular bone. Three NCCL morphological models were examined: Mixed (MI), Sauce (SA) and Wedged-shape (WS). All types of lesions were analyzed with and without restoration. The models were considered homogeneous and elastic. In each model three load types: 100N: vertical load (VL), buccal load (BL) and palatine load (PL) were applied. The Maximum Principal Stress values were analyzed. The quantitative analysis of stress (MPa) was identified at five points of the NCCLs according to the morphology of the lesion type: initial point, superior wall, center of lesion, inferior wall and final point. It was found that NCCLs restored with composite resin exhibited stress distribution patterns similar to the healthy tooth model, independent of morphology and load. The Palatine Load was responsible for providing the highest values of accumulated tensions on the NCCL. The highest values of tensile stress on NCCL areas were found in the models without composite resin restoration, which had received PL. It was concluded that the different NCCL morphologies had little effect on stress distribution patterns. The major factors that affected the biomechanical behavior of premolars presenting NCCL were load type and the presence of composite restoration.

O objetivo desse estudo foi analisar a influência de diferentes morfologias de lesões cervicais não cariosas (LCNCs) em pré-molares superiores restaurados ou não com resina composta, aplicando três diferentes carregamentos oclusais. A hipótese é que a morfologia, o tipo de carregamento e a restauração influenciem no padrão de distribuição de tensão. Através do método de elementos finitos, foram simulados modelos bidimensionais, homogêneos, lineares e elásticos. O modelo do dente hígido (H) foi representado com as seguintes estruturas: dentina, polpa, esmalte, ligamento periodontal, osso cortical, osso trabeculado e posteriormente simulou-se três morfologias de LCNCs: Mista(MI), Arredondada (SA) e em forma de Cunha (WS). Todos os tipos de lesão foram analisados com a presença e ausência da restauração. Em cada modelo foram aplicados três diferentes tipos de carregamento, com 100 N cada: carregamento vertical (VL), carregamento vestibular (BL) e carregamento palatino (PL). A análise quantitativa das tensões foi realizada através do critério de Tensão Máxima Principal em cinco regiões de cada LCNC, nos seguintes pontos: ponto inicial, parede superior, centro da lesão, parede inferior e ponto final. Como resultado, as LCNCs restauradas com resina composta apresentaram distribuição de tensão semelhante a do modelo do dente hígido, independente da morfologia e do carregamento. O carregamento palatino foi responsável pelos maiores valores de acúmulo de tensão nas LCNCs. É possível conclui que Os diferentes tipos de morfologia das LCNCs apresentaram pequena influencia no padrão de distribuição de tensão. Os fatores de maior influência no comportamento biomecânico de pré-molares foram o tipo de carregamento e a presença da restauração.