Drilling into debris-rich basal ice at the bottom of the NEEM (Greenland) borehole

After the NEEM (Greenland) deep ice-core drilling was declared terminated with respect to developing stratigraphic climate reconstructions, efforts were turned toward collecting basal ice-sheet debris and, if possible, drilling into the bedrock itself. In 2010, several meters of banded debris-rich ice were obtained under normal ice-drilling operations with the NEEM version of the Hans Tausen (HT) drill, but further penetration was obstructed by a rock in the path of the drill head at 2537.36 m. During short campaigns in 2011 and 2012, attempts were made to penetrate further using various reinforced ice cutters mounted on the HT drill head, tailored to cut through rock. These had some success in penetrating coarse material, but produced severely damaged cutters. Additionally a 51 mm diameter diamond cutting tipped rock drill was adapted to fit the NEEM drill. With this device, several additional meters of core containing subglacial sediments, rocks and rock fragments were collected. With these tools 1.39 m of additional material were obtained during the 2011 field season, and 7.1 m during 2012. Subglacial water refreezing into the newly formed borehole hindered further penetration, and the bedrock interface was not reached before final closure of the NEEM Camp.

Periodontal regeneration - furcation defects: a consensus report from the AAP Regeneration Workshop

BACKGROUND Treatment of furcation defects is a core component of periodontal therapy. The goal of this consensus report is to critically appraise the evidence and to subsequently present interpretive conclusions regarding the effectiveness of regenerative therapy for the treatment of furcation defects and recommendations for future research in this area. METHODS A systematic review was conducted before the consensus meeting. This review aims to evaluate and present the available evidence regarding the effectiveness of different regenerative approaches for the treatment of furcation defects in specific clinical scenarios compared with conventional surgical therapy. During the meeting, the outcomes of the systematic review, as well as other pertinent sources of evidence, were discussed by a committee of nine members. The consensus group members submitted additional material for consideration by the group in advance and at the time of the meeting. The group agreed on a comprehensive summary of the evidence and also formulated recommendations for the treatment of furcation defects via regenerative therapies and the conduction of future studies. RESULTS Histologic proof of periodontal regeneration after the application of a combined regenerative therapy for the treatment of maxillary facial, mesial, distal, and mandibular facial or lingual Class II furcation defects has been demonstrated in several studies. Evidence of histologic periodontal regeneration in mandibular Class III defects is limited to one case report. Favorable outcomes after regenerative therapy for maxillary Class III furcation defects are limited to clinical case reports. In Class I furcation defects, regenerative therapy may be beneficial in certain clinical scenarios, although generally Class I furcation defects may be treated predictably with non-regenerative therapies. There is a paucity of data regarding quantifiable patient-reported outcomes after surgical treatment of furcation defects. CONCLUSIONS Based on the available evidence, it was concluded that regenerative therapy is a viable option to achieve predictable outcomes for the treatment of furcation defects in certain clinical scenarios. Future research should test the efficacy of novel regenerative approaches that have the potential to enhance the effectiveness of therapy in clinical scenarios associated historically with less predictable outcomes. Additionally, future studies should place emphasis on histologic demonstration of periodontal regeneration in humans and also include validated patient-reported outcomes. CLINICAL RECOMMENDATIONS Based on the prevailing evidence, the following clinical recommendations could be offered. 1) Periodontal regeneration has been established as a viable therapeutic option for the treatment of various furcation defects, among which Class II defects represent a highly predictable scenario. Hence, regenerative periodontal therapy should be considered before resective therapy or extraction; 2) The application of a combined therapeutic approach (i.e., barrier, bone replacement graft with or without biologics) appears to offer an advantage over monotherapeutic algorithms; 3) To achieve predictable regenerative outcomes in the treatment of furcation defects, adverse systemic and local factors should be evaluated and controlled when possible; 4) Stringent postoperative care and subsequent supportive periodontal therapy are essential to achieve sustainable long-term regenerative outcomes.

Vinylsiloxanether: a new impression material. Clinical study of implant impressions with vinylsiloxanether versus polyether materials.

The performance of three elastomeric materials for the open monophase implant impressions technique was tested under the following clinical conditions: polyether (IM) and vinylsiloxanether without (ID) and with additional simultaneous splinting of the implant impression copings with a higher shore hardness A-silicone (IDF).