Primary teeth show less protecting factors against root resorption.

BACKGROUND: Physiological root resorption differentiates primary from permanent teeth. The understanding of what protects and regulates root resorption might help to develop therapies to its control. AIM: To verify the presence and distribution of ECRM and the expression of CK14, OPG, TRAP and COX-2 in the periodontal ligament (PDL) of human primary and permanent teeth. Design. Eight primary teeth undergoing physiological or pathological root resorption and 4 permanent teeth were immunohistochemically processed for CK14, TRAP, COX-2 and OPG expression. RESULTS: PDL from primary and permanent teeth showed similar morphological features; however, fewer ECRM clusters and higher immunoreactivity to CK14 were found in primary PDL. In permanent teeth, ECRM were distributed along the entire PDL tissue. Howship's lacunae were found only in primary teeth, associated with the presence of TRAP-positive cells and increase in COX-2 expression. OPG expression in primary PDL was detected in nonresorptive cervical areas and in lacunae showing reparative tissue. It was observed higher expression of OPG in all permanent teeth when compared to primary specimens. CONCLUSIONS: It may be concluded that PDL from primary teeth shows less ECRM clusters and lower expression of OPG. These features may be associated with lower protection against root resorption in primary teeth.

Release of simvastatin from scaffolds of poly(lactic-co-glycolic) acid and biphasic ceramic designed for bone tissue regeneration.

The aim of this study was to evaluate the release of simvastatin from scaffolds composed of poly(lactic-co-glycolic) acid (PLGA) and biphasic ceramic designed for bone engineering and to assess the physico-chemical and mechanical properties of the scaffolds. Samples with 30% and 70% porosity were obtained with 0, 2, 5, and 8 wt %. of simvastatin through the solvent evaporation technique and leaching of sucrose particles. Scaffold degradation and simvastatin release were evaluated in phosphate-buffered saline. Scaffolds were analyzed by scanning electron microscopy and microtomography for two-dimensional and three-dimensional morphological characterization of the porosity, connectivity, and intrinsic permeability. The mechanical characterization was conducted based on the compressive strength and the chemical characterization by differential scanning calorimetry and energy dispersive X-ray spectroscopy. Gradual and prolonged simvastatin release from the scaffolds was observed. The release followed the Korsmeyer kinetics model with the predominance of case II transport for 30% porosity scaffolds, and anomalous behavior for the 70% porosity samples. Simvastatin release was also influenced by the slow scaffold degradation due to the strong chemical interaction between simvastatin and PLGA, as observed by differential scanning calorimetry. The scaffolds presented spherical and sucrose crystal-shaped pores that resulted in a homogenous porosity, with a predominance of open pores, ensuring interconnectivity. Simvastatin incorporation into the scaffolds and increased porosity did not influence the mechanical properties. The scaffolds presented gradual and prolonged simvastatin release, with satisfactory physico-chemical and mechanical properties. The scaffolds presented gradual and prolonged simvastatin release, with satisfactory physico-chemical and mechanical properties, a promise for applications in bone regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2152-2164, 2019.

Level of agreement between self-administered and interviewer-administered CPQ8₋10 and CPQ1₋14.

OBJECTIVES: The aim of the present study was to assess the psychometric properties and level of agreement between the self-administered and interviewer-administered Child Perceptions Questionnaire (CPQ) for children between 8 and 10 years of age (CPQ(8-10) ) and between 11 and 14 (CPQ(11-14) ) years of age. METHODS: A randomized cross-over study was carried out, involving 180 children (Group 1 - 90 children between 8 and 10; Group 2 - 90 children between 11 and 14 years of age) in the state of Minas Gerais, Brazil. All children completed both administration modes of the CPQ; half of each group received interviewer-administered mode first [Subgroup A (CPQ(8-10) n = 45) and Subgroup C (CPQ(11-14) n = 45)], and the other half performed the self-administered mode first [Subgroup B (CPQ(8-10) n = 45) and Subgroup D (CPQ(11-14) n = 45)]. Test-retest reliability of each mode of administration was tested on 60 children (30 for CPQ(8-10) ; 30 for CPQ(11-14) ), who were not included in the other analyses. The level of agreement between scores on the self-administered and interviewer-administered versions of the CPQ(8-10) and CPQ(11-14) was established using the intraclass correlation coefficient (ICC). The order of presentation of both instruments was tested considering the four subgroups (A, B, C and D). The calculation of effect size proposed by Cohen (1992) was used to test the clinical significance of the findings. RESULTS: Both the self-administered and interviewer-administered versions of CPQ(8-10) and CPQ(11-14) demonstrated acceptable psychometric properties. Agreement between the administration modes for the CPQ(8-10) and CPQ(11-14) was 0.90 and 0.88 (ICC), respectively. With the exception of the functional limitation subscale, the scores of the subscales and overall score on the CPQ(8-10) were significantly higher in the group of children who responded to the interviewer-administered measure first. With the CPQ(11-14) , statistically significant differences were found only for the emotional well-being subscale. CONCLUSIONS: Both administration modes of the CPQ(8-10) and CPQ(11-14) demonstrated satisfactory psychometric properties and a high level of agreement. Although statistically significant differences were observed for oral symptoms, emotional well-being and social well-being, with the first administration of the interviewer-administered version, the effect of the order of administration had small to medium effects on the CPQ scores.

Endothelial cells enhance tumor cell invasion through a crosstalk mediated by CXC chemokine signaling.

Field cancerization involves the lateral spread of premalignant or malignant disease and contributes to the recurrence of head and neck tumors. The overall hypothesis underlying this work is that endothelial cells actively participate in tumor cell invasion by secreting chemokines and creating a chemotactic gradient for tumor cells. Here we demonstrate that conditioned medium from head and neck tumor cells enhance Bcl-2 expression in neovascular endothelial cells. Oral squamous cell carcinoma-3 (OSCC3) and Kaposi's sarcoma (SLK) show enhanced invasiveness when cocultured with pools of human dermal microvascular endothelial cells stably expressing Bcl-2 (HDMEC-Bcl-2), compared to cocultures with empty vector controls (HDMEC-LXSN). Xenografted OSCC3 tumors vascularized with HDMEC-Bcl-2 presented higher local invasion than OSCC3 tumors vascularized with control HDMEC-LXSN. CXCL1 and CXCL8 were upregulated in primary endothelial cells exposed to vascular endothelial growth factor (VEGF), as well as in HDMEC-Bcl-2. Notably, blockade of CXCR2 signaling, but not CXCR1, inhibited OSCC3 and SLK invasion toward endothelial cells. These data demonstrate that CXC chemokines secreted by endothelial cells induce tumor cell invasion and suggest that the process of lateral spread of tumor cells observed in field cancerization is guided by chemotactic signals that originated from endothelial cells.