Genetic diversity of native populations of Croton tetradenius Baill. using ISSR markers.

Brazil has about 300 Croton species in different types of vegetation. Croton tetradenius Baill., which is endemic to the Northeast region and predominant in the Caatinga vegetation, stands out among the several species of this genus. Considering the importance of knowing the genetic variability of a species, the objective of this study was to analyze the genetic diversity of the genotypes of natural populations of C. tetradenius in the State of Sergipe, using ISSR molecular markers. Forty individuals were sampled in four natural populations of the State of Sergipe, Brazil. Thirteen primers were used for DNA amplification using ISSR-PCR, totaling 77 amplified fragments, of which 94.8% were polymorphic. Results of the cluster analysis obtained by the Jaccard's similarity index, using the UPGMA method, resulted in the formation of six distinct clusters. Analysis of molecular variance (AMOVA), used to estimate the genetic variability among populations, revealed significant genetic variance (P < 0.01) between and within the studied populations, and most of the genetic diversity was found (87%) within populations. According to the Jaccard's similarity index, none of the studied plants was genetically identical. CTE210 and CTE305 presented high similarity index (0.76), while CTE105 presented low similarity index (<0.16) with all related individuals. ISSR markers were efficient and allowed the formation of a molecular profile, and had sufficient polymorphism to estimate the genetic variability between the accessions of the studied populations.

Guided bone regeneration in the treatment of a large periapical lesion: a case report.

A large (19 mm x 24 mm) periapical lesion associated with tooth #10, perforating both the labial and palatal cortical plates, was treated with decalcified freeze-dried bone allograft and guided bone regeneration. The membranes were removed after a seven-month healing period. Complete osseous reconstruction of the cortical plates was noted. Biopsies demonstrated healing with mature bone and hemopoietic marrow. Few particles of decalcified freeze-dried bone could be observed. Graft particles that remained were surrounded by new bone. The learning objective of this article is to present the regeneration procedure utilized along with the histologic biopsy results to the clinician.