Osteotome sinus floor elevation without bone grafting and simultaneous implant placement in the atrophic maxilla: A pilot study

Aims: This study evaluated the clinical and radiographic outcome of implants placed in the posterior maxilla with the osteotome sinus floor elevation (OSFE) technique without graft material. Materials and Methods: Twenty-seven 4.1-mm-diameter dental implants (Straumann AG, Basel, Switzerland) were placed to 17 sinuses with residual bone height of ≤10 mm and ≥5 mm to rehabilitate 23 molar and 4 premolar sites. Implants were simultaneously placed with the OSFE procedure without graft material. Results: All implants were successfully integrated after 8-12 weeks healing time. At the 2-year follow-up, all the implants presented the survival criteria proposed by Buser et al. and Cochran et al. Conclusion: The OSFE technique without grafting material may be predictable because the success rate was 100% in this study. Implants gained endo-sinus bone despite the lack of graft material. More patients and longer follow-up are needed to validate the results of this pilot study

Simulation of clinical fractures for three different all-ceramic crowns

Comparison of fracture strength and fracture modes of different all-ceramic crown systems is not straightforward. Established methods for reliable testing of all-ceramic crowns are not currently available. Published in-vitro tests rarely simulate clinical failure modes and are therefore unsuited to distinguish between the materials. The in-vivo trials usually lack assessment of failure modes. Fractographic analyses show that clinical crowns usually fail from cracks initiating in the cervical margins, whereas in-vitro specimens fail from contact damage at the occlusal loading point. The aim of this study was to compare three all-ceramic systems using a clinically relevant test method that is able to simulate clinical failure modes. Ten incisor crowns of three types of all-ceramic systems were exposed to soft loading until fracture. The initiation and propagation of cracks in these crowns were compared with those of a reference group of crowns that failed during clinical use. All crowns fractured in a manner similar to fracture of the clinical reference crowns. The zirconia crowns fractured at statistically significantly higher loads than alumina and glass-ceramic crowns. Fracture initiation was in the core material, cervically in the approximal areas