Suscettibilità Genetica alla Parodontite Aggressiva: Analisi di Polimorfismi in Geni Candidati

BACKGROUND & RATIONALE Aggressive Periodontitis (AgP) is a complex multifactorial periodontal disease where genetic and environmental factors are thought to play a paramount pathogenic role. Patients with AgP are characterized by a rapid and severe periodontal destruction in mainly younger individuals. While putative perio-pathogenic bacteria constitute the primary extrinsic agent in the etiology of AgP, the risk of developing periodontal disease is not the same for all individuals, suggesting that host factors, potentially related to the genetic make-up, are involved in determining the disease susceptibility. IL-1a and IL-1b, two functionally similar molecules, have been recognized as central proinflammatory cytokines. IL-1ra is an anti-inflammatory non-signaling molecule that competes for receptor binding with IL-1a and IL-1b. The overall contribution of IL-1 to the pro-inflammatory response depends on the balance between these three molecules. Polymorphisms of the Interleukin-1 (IL-1) gene cluster family have been described in association with inter-individual differences of IL-1 levels upon bacterial challenge and they have been proposed as potential genetic markers for periodontal diseases. AIM OF THE STUDY In our previous studies, we have investigated the role of IL-1 genes in explaining the individual susceptibility to both plaque-induced gingivitis and AgP. With respect to AgP, we examined 6 polymorphisms derived from genes of the IL-1 cluster comparing 40 AgP patients with 96 periodontally healthy controls. We tested the association through both the analysis of allelic/genotypic distributions as well as by constructing a map in LD units of the candidate region 2q13–14. Our analyses highlighted the presence of recombination hot spots between the IL-1B+3954 and IL-1B-511 variants and around the IL-1RN (VNTR) marker. The multilocus modelling of association with disease gave a location for the association peak at the IL-1B+3954 marker. Moreover, haplotype analysis identified the IL-1B+3954-IL-1B-511 haplotype as the one having the lowest p-value in the region. In view of this preliminary results, we decided to further investigate the role of IL-1 cluster genes in the pathogenesis of generalized AgP. In particular, we were aware that the main limitations of our previous studies were the small number of the genetic variants investigated and the limited size of the study population. Thus, for the present study, these two constrains have been settled by implementing the study cohort as well as by covering the chromosomal region of interest with an adequate number of single nucleotide polymorphisms (SNPs). MATERIALS AND METHODS Study Population A total of 95 generalized AgP patients (29 males and 66 females, mean age 43.4 ± 7.7) were recruited among those seeking care for periodontal treatment at two different University centers: the Research Center for the Study of Periodontal Diseases, University of Ferrara (56 subjects) and the Department of Odontostomatological, Orthodontic and Surgical Disciplines, Second University of Naples, (39 subjects). Patients were enrolled for genetic genotyping only if they fulfilled the criteria for a clinical diagnosis of generalized AgP at the time of the first (initial) examination according to AAP World Workshop definition. 121 systemically healthy individuals, (60 males and 61 females, mean age 30.1 ± 4,7), were recruited as controls. They were selected if they showed no interproximal attachment loss greater than 2 mm at any of the fully erupted teeth. All subjects enrolled for the study were unrelated Caucasian Italian and chosen among current and permanent residents of Ferrara and Naples areas, respectively. Written informed consent was provided by all participants before study inclusion. The study protocol was approved by the respective local ethical committees. Genotyping Genomic DNA was extracted from peripheral blood leukocyte using the QIAamp blood Kit (QIAGEN Inc., Germany) or a standard proteinase K digestion and phenol/chloroform extraction method. A minimum of 1g of genomic DNA (diluted in 0,2x TE buffer at 10 ng per microliter) from patients and controls was arrayed on 96-well plates and DNA concentrations were determined by fluorescence measurement with molecular probes (Invitrogen, Molecular Probes, USA). For each of the 216 samples of DNA extracted, the genotyping of the 70 polymorphisms selected was realized on Sequenom MassARRAY® platform (Sequenom, San Diego, CA), using protocol iPLEXTM. Statistical analysis A c2 test (p>0.05) was used to assess that the genotype distributions of the polymorphisms fulfilled the criteria of Hardy–Weinberg equilibrium (HWE). The analysis of the potential association between the candidate genes/regions and AgP, in the two samples considered, was verified through the application of the following specific statistical programs: The PLINK software [version 1.00] (http://pngu.mgh.harvard.edu/~purcell/plink/) was used to compare the allele counts in cases and controls by Fisher’s exact test and to calculate odds ratios (OR) with 95% confidence intervals. PLINK was also used to test for population stratification and for allelic heterogeneity between the two subgroups of subjects (from Ferrara and Naples area). From population genotype data, haplotypes were reconstructed by using PLINK toolset which implements a Expectation Maximization (EM) algorithm and performs the sliding window haplotype association analysis by the Chi square test. The CHROMSCAN program (http://cedar.genetics.soton.ac.uk/pub/PROGRAMS), was used to construct a LD map in Linkage Disequilibrium Units (LDUs) which has additive distances and locations monotonic with physical and genetic maps. The level of significance was chosen as P<0.05. When necessary, P values were subject to Bonferroni’s correction for multiple comparisons. RESULTS Control for Hardy-Weinberg Equilibrium After quality control, among the 70 markers selected, eight polymorphisms were excluded from further analysis because two SNPs were found to be monomorphic and six markers had a call rate less than 20%. Among the remaining sixty-two SNPs successfully characterized, three markers in the sample of affected subjects and four SNPs in the group of controls showed significant deviation from HWE. These latter SNPs were excluded from the subsequent analyses. Test for population stratification Based on the whole genome SNPs data, the 216x216 matrix of the pairwise identity-by-state (IBS) genetic distances was constructed using PLINK and used for Multidimensional Scaling (MDS). Through MDS, it was possible to obtain a graph where each point represented an individual and the two axes generated an image of the data reduced in two dimensions. The uniform distribution of points on the graph clearly indicated the absence of heterogeneity between the two subpopulations. To further check for homogeneity among populations, the Cochran-Mantel-Haenszel (CMH) test for stratified samples was also performed. At the CMH test, the most heterogeneous marker observed was the rs895497 variant which resulted not significant different in the two populations [c2 [CMH] = 2.1, p-value=0.146, OR[CMH] = 1.4 (95%CI 0.90-2.08)]. From these tests it was possible to assume that the two subpopulations sampled, Ferrara and Naples, were nearly genetically homogeneous for the investigated chromosomal region and, therefore, in the subsequent analyses, could be considered as a single group divided into cases and controls. Single-point analysis From all allelic and genotypic tests, a significant level less than 5% was found only for genotypic distribution of rs6751201 polymorphism, which maps in the tenth intron of the SEC7 homolog gene (p-value=0,025). However, this association did not hold the statistical significance after Bonferroni correction. LD structure of 2q13-14 region From the CHROMSCAN program, an LD map of the region 2q13–14 under the Malécot model for multiple markers was constructed. The coverage choice for each LDU was of four SNPs, with a mean distance between SNPs of 15.75 ± 11 Kb. The block-step structure of the candidate region was built by plotting, on the kb distances, the LDU locations obtained from: a) HapMap public data from Caucasian population, b) the entire Italian dataset, c) unaffected Italian subjects and d) AgP patients. LD maps showed very similar profiles and a close correspondence was found between the four LD maps. The chromosomal structure of the 2q13- 14 region obtained from Italian Caucasian data, that shows a total length of 16 LDUs, confirmes the profile obtained from the HapMap database. Haplotypic reconstruction On the basis of the "block-step" pattern obtained both from the LD map and from pairwise analysis, the 58 polymorphisms used have been subdivided in four regions grouping 15 (blocks 1 to 4), 10 (Blocks 5 to 8), 13 (Blocks 9 to 13) and 16 (Blocks 14 to 17) SNPs respectively. Within each region, the haplotypes have been reconstructed using the Expectation-Maximization algorithm implemented in PLINK software by means of sliding windows of size three and six (shifting 1 SNP at a time). Haplotype distributions were compared in cases and controls to test for haplotypic association with AgP. None of the possible inferred haplotypes showed a significant association with AgP at the global test. Inferred haplotypes, which contained the gene variants mapping within IL1F6 and IL1F8 (region 1, block 4, SNPs: rs879711, rs895497, rs2305150, rs1562302), demonstrated a significant or borderline association with disease (pvalues ranging from 0.028 to 0.058) both using 3 and 6 windows. Combined haplotypes consisting of SNPs mapping within IL1B (SNPs: rs3917368, rs1143634, rs1143627, rs16944) demonstrated only a very weak association with disease (p-values: 0.046 and 0.053) only for windows of size six. No significant association was found in the region where IL1A and IL1RN map. CONCLUSIONS In conclusion, within the limitation of the present study, our findings failed to support the existence of a causative variant for generalized AgP within the candidate region, where IL-1A, IL-1B and IL1RN genes reside, in an Italian Caucasian population

Minimal invasiveness in the surgical treatment of intraosseous defects: A systematic review

The modern approach to regenerative treatment of periodontal intraosseous defects should aim at maximizing the clinical outcomes while minimizing the invasiveness (pain, complications, aesthetic impairment, chair time, and costs) of the procedure. The present systematic review evaluated the effect of flap design, regenerative technology, and perioperative and postoperative adjunctive protocols on invasiveness. Overall, the results of the 13 included trials indicate that: (a) the elevation of a single (buccal or lingual) flap positively influences the intensity of postoperative pain and improves the quality of early wound healing compared with double flaps; (b) while the adjunctive use of a membrane is associated with significantly longer surgery-related chair time and higher postoperative pain, the adjunctive use of enamel matrix derivative at sites receiving a graft significantly reduces postoperative pain; also, graft materials showed no significant impact on invasiveness; (c) open flap debridement performed through the elevation of a single flap may lead to substantial clinical improvements of the lesion with reduced surgery-related chair time and costs, thus representing a promising alternative to regenerative treatment. However, for such an approach, a histological evaluation of the nature of the reconstructed tissues is still lacking, and the presurgery conditions (eg, probing depth, defect severity, and defect morphology), which may benefit in terms of invasiveness, have not yet been defined; and (d) intraoperative and postoperative low-level laser biostimulation of the defect site may favorably modulate the postoperative course

Plasma rich in growth factors in human extraction sockets: a radiographic and histomorphometric study on early bone deposition

Objectives To determine whether and to what extent the additional application of plasma rich in growth factors ( PRGF ) to an extraction socket may influence the early bone deposition, as assessed by micro‐computed tomography (micro‐ CT ) scan as well as histomorphometric markers. Material and methods Twenty‐eight patients (age range: 34–74 years) contributing 36 extraction sockets were included in the study. Sockets were either treated with PRGF ( PRGF group; 18 sites in 11 patients) or left to spontaneous healing (control group; 18 sites in 17 patients). Radiographic and histomorphometric analysis was performed on bone cores trephined from each healing socket after 4–6 (T1) or 7–10 (T2) weeks of healing. Results Patients treated with PRGF application showed (i) similar bone volume and tissue mineral content, (ii) a trend, although not statistically significant, toward a greater number of CD 68+ cells (at T 1 and T 2) and v VW + cells (at T1), and (iii) a similar OCN staining score throughout the study, when compared with control group. Conclusions Plasma rich in growth factors‐treated group did not show any enhancement in early (4 and 8 weeks) bone deposition compared with control group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100296/1/clr12033.pd

PIBIC/CNPq no divã

Resumo: A pesquisa tem como objetivo analisar a efetividade do processo de iniciação científica promovido pelo PIBIC/CNPq na formação de pesquisadores em Contabilidade, por meio da ampliação das lentes com as quais se observam o fenômeno (iniciação científica), transpondo as fronteiras institucionais desta atividade pela interrogação e confrontação do posicionamento dos diferentes atores integrantes do sistema, no qual simbolizam uma peça fundamental, acerca do desenvolvimento do PIBIC/CNPq. A coleta dos dados ocorreu por meio de pesquisa documental e entrevistas, cujos roteiros foram adaptados do estudo de Laursen et al. 2010, com respaldo nos elementos constitutivos e questões norteadoras de análise da Teoria da Atividade. Foram interrogados os orientadores e egressos que participaram do programa no curso de Ciências Contábeis de instituições que possuem PPG na área. A aplicação da técnica do discurso do sujeito coletivo nos depoimentos dos sujeitos revelou que as instituições não desenvolvem uma política de incentivo para a participação do programa de maneira efetiva, além de não disponibilizarem estrutura física para a execução dos projetos, limitando a permanência dos bolsistas na instituição. Em relação à conversão dos egressos, apurou-se uma taxa inferior em relação à taxa declarada pelo CNPq, sendo justificada pela atratividade exercida pelas ofertas do mercado, que remuneram melhor. No entanto, os egressos declaram que o PIBIC é um programa em potencial, sendo confirmatório com relação aos planos para a carreira

Parâmetros morfológicos e ópticos dos dentes anteriores superiores

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências da Saúde. Odontologia.O objetivo deste trabalho foi analisar a morfologia dental interna e externa de dentes anteriores superiores e reproduzir os parâmetros ópticos por meio de três técnicas restauradoras com resina composta. Para a análise morfológica externa, foi realizado um protocolo fotográfico das faces vestibular, palatal, incisal, mesial e distal da coroa dental de um incisivo central, um incisivo lateral e um canino (Câmera Nikon D3200, lente macro 105 mm Sigma, Flash circular Sigma e Estúdio fotográfico com 2 tochas Atek com softbox). Na sequência, os dentes foram submetidos a um registro de cor com espectrofotômetro (Easyshade, VITA) e moldagem com silicone de adição (Variotime, Heraus Kulzer) para obtenção de guias restauradoras. Os espécimes foram seccionados longitudinalmente em sentido mésio-distal ou vestíbulo-palatal (ISOMET) para análise da morfologia interna. Com o auxílio das guias, todos os dentes foram reproduzidos com resina composta, por três técnicas: técnica monocromática (Charisma Classical), técnica da dupla camada de cores (Charisma Diamond) e a técnica de estratificação policromática (Charisma Diamond). Em seguida, os mesmos foram submetidos a fotografia e mensuração da cor pelo espectrofotômetro. As três técnicas apresentaram resultado variável, a técnica monocromática apresentou saturação igual ao dente natural e a técnica estratificada apresentou os melhores resultados estéticos.The objective of this study was to analyze the internal and external dental morphology of upper anterior teeth and to reproduce the optical parameters through three restorative techniques with composite resin. For the external morphological analysis, a photographic protocol of the vestibular, palatal, incisal, mesial and distal surfaces of the dental crown of a central incisor, a lateral incisor and a canine (Nikon D3200 camera, Sigma macro lens 105mm, Sigma circular flash and Photo studio with 2 Atek torches with softbox). Afterwards, the teeth were submitted to color registration with a spectrophotometer (Easyshade, VITA) and addition silicone molding (Variotime, Heraus Kulzer) to obtain restorative guides. The specimens were sectioned longitudinally mesio-distal or vestibular-palatal (ISOMET) for analysis of internal morphology. With the help of the guides, all the teeth were reproduced with composite resin, using three techniques: monochromatic technique (Charisma Classical), double layer technique (Charisma Diamond) and color technique of Charisma Diamond. Afterwards, they were submitted to color spectrophotometer photography and color measurement. The three techniques presented variable results, the monochromatic technique showed saturation equal to the natural tooth and the stratified technique presented the best aesthetic results

The Effect of Partially Exposed Connective Tissue Graft on Root‐Coverage Outcomes: A Systematic Review and Meta‐Analysis

The aim of this systematic review was to compare the root‐coverage outcomes of using a partially exposed connective tissue graft (CTG) technique with a fully covered CTG technique for root coverage. An electronic search up to February 28th, 2017, was performed to identify human clinical studies with data comparing outcomes of root coverage using CTG, with and without a partially exposed graft. Five clinical studies were selected for inclusion in this review. For each study, the gain of keratinized gingiva, reduction of recession depth, number of surgical sites achieving complete root coverage, percentage of root coverage, gain of tissue thickness, and changes of probing depth and clinical attachment level were recorded. Meta‐analysis for the comparison of complete root coverage between the two techniques presented no statistically significant differences. A statistically significant gain of keratinized tissue in favor of the sites with an exposed CTG and a tendency of greater reduction in recession depth were seen at the sites with a fully covered CTG. Based on the results, the use of a partially exposed CTG in root‐coverage procedures could achieve greater gain in keratinized gingiva, while a fully covered CTG might be indicated for procedures aiming to reduce recession depth

Microscope and microâ camera assessment of Schneiderian membrane perforation via transcrestal sinus floor elevation: A randomized ex vivo study

ObjectiveWe sought to assess the effectiveness of using a microscope and nonâ invasive camera for assessing sinus membrane perforations during transcrestal sinus floor elevation (TSFE).Materials and methodsFive fresh human cadaver heads corresponding to eight maxillary sinuses (six bilateral and two unilateral) underwent 4 TSFEs per sinus (a total of 32 single site elevations). Each elevation was randomly assigned to receive a three or six mm membrane elevation height (MEH). A microscope and microâ camera were used to assess the sinus membrane perforation. Afterwards, radiological and clinical membrane perforation assessments were performed. The statistical analysis results are expressed using the means, standard deviations, range values of the residual ridge height (RRH), residual ridge width (RRW), sinus membrane thickness (SMT) and incidence of perforation (IoP). Generalized linear methods were used to test for the correlation of RRH and MEH to the microscope and microâ camera perforation assessments and the correlation of microscope and microâ camera assessments with the postâ operative CBCT and crestal liquid evaluation.ResultsThe cumulative percentage of IoP was 40.62%, (23.07% with 3 mm MEH, and 76.92% with 6 mm MEH, p < 0.05). The perforation assessed using either the microscope or microâ camera coincided with the postâ operative CBCT and crestal liquid assessment in 87.55% sites. No significant correlation was found between the microscope or microâ camera assessments with RRH or MEH.ConclusionApplication of a microscope and microâ camera during transcrestal sinus floor elevation may allow the detection of the integrity of the Schneiderian membrane with greater than 85% accuracy in this ex vivo model.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149727/1/clr13453.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149727/2/clr13453_am.pd