Unusual clinical presentation in a family with catecholaminergic polymorphic ventricular tachycardia due to a G14876A ryanodine receptor gene mutation

A family was identified, of whom which 11 members were carriers of the G14876A ryanodine 2 receptor mutation. All but 1 were symptomatic at the time of the study. Exercise testing showed bidirectional or polymorphic arrhythmias in 4 patients, whereas in 5 patients, it showed monomorphic or rare minor polymorphic ventricular arrhythmias. Two young patients died suddenly at rest while asleep. This study demonstrates that arrhythmias occurring during exercise stress testing in patients affected by catecholaminergic polymorphic ventricular tachycardia (CPVT) could be minor even in very symptomatic patients. The diagnosis of CPVT must be considered in these patients with a familial history of typical CPVT.     

A novel in vitro approach to assess the fit of implant frameworks

Objective: To introduce a new strain gauge approach to assess the fit of fixed implant frameworks. Materials and methods: A partially edentulous epoxy resin mandible model received two Straumann implants in the area of the lower left second premolar and second molar. The model was used to fabricate four zirconia and four identical cobalt–chromium alloy frameworks using a laboratory computer‐aided design/computer‐aided manufacturing (CAD/CAM) system. A total of four linear strain gauges were then bonded around each implant on the peri‐implant structure (mesial, distal, buccal, and lingual). The experimental part was composed of two phases: qualitative and quantitative. For the qualitative assessment, the model was verified by recording the response of each strain gauge while applying a near‐constant force of known directions on each implant. For the quantitative phase, the frameworks were attached on the implants and the screws were torqued to 15 N cm. Results: In the qualitative phase, the strain gauge response to every force direction was recorded. After attaching the frameworks, all frameworks produced measurable strains, but with different strain patterns. Upon correlating the two phases, the zirconia frameworks were found to be slightly smaller than the inter‐implant distance, whereas the cobalt–chromium alloy frameworks tended to be slightly larger than the inter‐implant distance. Conclusions: The proposed technique is not only valid for detecting implant framework misfit but also for determining the form of inaccuracies. Model verification is an essential informative step to aid the interpretation of the pattern of framework distortion. To cite this article:
Abduo J, Bennani V, Lyons K, Waddell N, Swain M. A novel in vitro approach to assess the fit of implant frameworks. Clin. Oral Impl. Res. 22 , 2011; 658–663
doi: 10.1111/j.1600‐0501.2010.02019.x     

Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part IV: clinical effects on tissue healing

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this fourth article, investigation is made into the previously evaluated biology of PRF with the first established clinical results, to determine the potential fields of application for this biomaterial. The reasoning is structured around 4 fundamental events of cicatrization, namely, angiogenesis, immune control, circulating stem cells trapping, and wound-covering epithelialization. All of the known clinical applications of PRF highlight an accelerated tissue cicatrization due to the development of effective neovascularization, accelerated wound closing with fast cicatricial tissue remodelling, and nearly total absence of infectious events. This initial research therefore makes it possible to plan several future PRF applications, including plastic and bone surgery, provided that the real effects are evaluated both impartially and rigorously.