the fine art of examining a scientific paper was emphasised to us during an excellent paper review yesterday. the topic of the OS Journal Club session was guided bone regeneration and membranes, focussing on the PhD paper of a particular oral surgeon in his quest to understand the importance of membranes in guided bone regeneration. one of the salient points brought up was that the PhD student's research was done on rats, whereby he had to hack up a whole bunch of rat mandibles. time consuming surgery for sure, especially in such a tiny, fiddly, smelly animal model. his conclusion was that for block grafts, at least, while the placement of membranes did not give a significantly better result in terms of graft outcome, the smaller confidence intervals for the membrane group once he plotted his stats indicated that he would still like to put in his Gore-Tex for his grafts.
this was picked up on by members of the floor; Gore-Tex has its own little problems. while much more able to hold its shape that the equivalent collagen membrane, once a Gore-Tex membrane gets exposed infection (and loss of the whole chunk of graft) happens very rapidly. post-op infections seem to correlate to size; the bigger the graft area, the bigger the Gore-Tex, the larger the area of flap which will not benefit from vascularisation of the graft region (due to the interposed Gore-Tex barrier) and hence the higher the chance of failure. this was practically eliminated in the 5mm diameter defect and graft sites in the rats. the differing immune and wound healing physiologies were also mentioned as significant, with a pithy quote from Prof Henk Tideman to sum it all up. questioning the over-reliance on animal experimental models, he said
'...you can put poop in a dog and it will still heal'
indeed...