Five new species in the genus Staurosirella (Bacillariophyta) from European freshwater habitats.

Several populations belonging to the genus Staurosirella have been observed in European rivers that were previously identified as Staurosirellapinnata. In light of the recent taxonomic revisions of the genus Staurosirella, the morphology of the unknown Staurosirella populations has been critically investigated using light and scanning electron microscopy. Following the comparison with previously described Staurosirella species, five taxa could not be identified using the currently available literature on the genus. These five taxa are described as new based on differences in valve outline; shape, size and structure of the apical pore fields; structure of the striae; and the presence, position and structure of the marginal spines. Two new species were described using historic collection material: Staurosirellabinodiformis sp. nov. and Svanheurckiana sp. nov. Two new species were observed in samples from rivers in Flanders: S.marginostriata sp. nov. and S.stoksiana sp. nov. whereas a fifth species was observed in rivers from Iceland: S.jonssoniana sp. nov. All new species are compared with similar Staurosirella species worldwide. Notes are added on their ecological preferences derived from both physicochemical data and the associated diatom flora.

Multi-modular bone healing assessment in a randomized controlled clinical trial of root-end surgery with the use of leukocyte- and platelet-rich fibrin and an occlusive membrane.

OBJECTIVES: The aim of this study was to assess in a multi-modular manner the bone healing 1 year post root-end surgery (RES) with leukocyte- and platelet-rich fibrin (LPRF) and Bio-Gide® (BG; Geistlich Pharma North America, Inc., Princeton, USA) as an occlusive membrane. MATERIALS AND METHODS: A randomized controlled clinical trial (RCT) of RES +/- LPRF and +/- BG was performed. The follow-up until 1 year post RES was performed by means of ultrasound imaging (UI), periapical radiographs (PR), and cone-beam computed tomography (CBCT). RESULTS: From the 50 included patients, 6 dropped-out during follow-up. For the 44 assessed patients (34 with UI and 42 with PR and CBCT), there was no evidence (p > 0.05) for an effect of LRPF, neither on UI measurements nor on CBCT assessments. On the contrary, there was an indication for a better outcome with BG. UI presented significant shorter healing time for the bony crypt surface (p = 0.014) and cortical opening (p = 0.006) for the groups with BG. The qualitative CBCT assessment for the combined scores of the apical area and cortical plane was significantly higher for BG (p = 0.01 and 0.02). The quantitative CBCT measurement for bone healing after 1 year was lower with BG (p = 0.019), as well as the percentage of non-zero values (p = 0.026), irrespective of the preoperative lesion size and type. Furthermore, UI seemed to be safer for frequent follow-up during the early postoperative stage (0-3 months), whereas CBCT gave more accurate results 1 year post RES. Amongst the assessors, the qualitative PR analysis was inconsistent for a favorable outcome 1 year post RES with LPRF (p = 0.11 and p = 0.023), but consistent for BG (p = 0.024 and p = 0.023). CONCLUSIONS: There was no evidence for improvement of bone healing when RES was applied with LPRF in comparison with RES without LPRF. However, RES with BG gave evidence for a better outcome than RES without BG. CLINICAL RELEVANCE: The addition of an occlusive membrane rather than an autologous platelet concentrate improved bone regeneration 1 year post RES significantly, irrespective of the assessment device applied. The accuracy of PR assessment is questionable.