Nobel Biocare Letter - (Page 7) Nobel Biocare Slide #8: Nobel attributes the position of a non-existent “seating platform of the RePlant Implant ” as the basis for its argument that “the NobelReplace Tapered drill does not prepare the shoulder deeply enough.” This argument is without merit or logic. As the RePlant’s threads engage bone at the base of the 2mm deep countersink created by the NobelReplace drill, continued Clinical Implications turning of the implant results in creation of threads in the socket. With the Replace implant in soft bone, these threads are created by compression and in dense bone they are created by the bone tap. With the RePlant implant, whether in soft or hard bone, they are created by the sharp leading edge of the long, vertical grooves cut in the threads similar to the grooves in a bone tap. This groove extends half way up the implant about 4 threads above the start of the tapered end of the implant. Both the Replace and RePlant implants maintain The design of the NobelRePlace Tapered Drills is intended for the the same major diameter above the tapered end, matching the seating profile of the NobelReplace Tapered implant collar, from diameter of the platform at the top of the implant. As soon as the shoulder up, in a variety of clinical situations. the first 4.3mmD thread in the sequence on the next page, Because the seating platform of the RePlant implant is further pass the base of the countersink in bone, threads are cut to above this shoulder, the NobelReplace Tapered drill does not prepare the shoulder deeply enough. their full depth and all the threads on the implant above that point just follow the threads created in the bone. Therefore, Nobel’s argument that the RePlant will hold up at the junction of its two thread types is spurious. If the ledge of bone created by the countersink section of the drill was capable of stopping the self-tapping seating of the RePlant implant, it would do so when the first major diameter thread made contact with the ledge, leaving about half the length of the implant projecting above the opening to the socket. Nobel Biocare Slide #10 states that (1) “Portion of the RePlant above the blue line (representing top of bone) (is) caused by premature seating due to increased collar height.” of the RePlant implant. As shown in the pictures below Slide 10, of a RePlant in a plastic block and removed from the block, this speculation is without basis and is so misguided as to be nothing other than intentionally misleading. Once the first thread is cut in the socket by a bone tap or self-tapping insertion, the threads of the implant follow until the implant bottoms out in the socket. What actually stops the insertion of both the Replace and RePlant implants is the socket itself that is dimensioned and tapered like the implant but slightly smaller than the threaded areas to provide bone engagement by the threads. TM TM TM TM Nobel Biocare Slide #10: Nobel’s representation of the “Clinical Implications” of placing a RePlant implant into a socket prepared by a NobelReplace drill is false and misleading. Nobel claims that a “Portion of the RePlant above the blue line (representing the crest of the ridge) (is) caused by premature seating due to increased collar height.” This is fundamentally false because the RePlant has no ledge to come in contact with the base of the countersink created by NobelReplace drills - it has continuous threads of the same diameter between the double lead body threads and the mini-threads, which blend with the 1mm collar at the top of the implant. The countersink part of a NobelReplace drill provides an untapped section of bone for the 1mm and 2mm collars of the Replace and RePlant. LEFT PICTURE: 4.3mmD - 13mmL RePlant inserted into a Plastic block self-tapping, following site preparation using the appropriate diameter and length Replace drill only. RIGHT PICTURE: Threads created in the plastic after Implant removed showing unthreaded 2mm collar section. The base of the countersink created by the NobelReplace length-specific drill will be replaced with bone threads as the first major diameter thread of the implant engages bone at the base of the countersink. This applies to selftapping insertion of the RePlant and to insertion of the Replace with or without use of the bone tap. The depth of the countersink created by the NobelReplace drill has no effect on the depth of the RePlant implant. Blue line indicates desired placement depth Portion of the RePlant above the blue line caused by premature seating due to increased collar height > may not be evident until the implant is inserted RePlant seating depth in site prepared with NobelReplaceTM Tapered drill 4.3mmD/13mmL RePlant 1mm Collar 2.5mm Mini-threads Plastic Threaded Socket Unthreaded Collar 1st 4.3mmD Full Thread No Ledge to impede insertion 7
Table of Contents Feed for the Digital Edition of Nobel Biocare Letter Nobel Biocare Letter Nobel Biocare Letter - (Page 1) Nobel Biocare Letter - (Page 2) Nobel Biocare Letter - (Page 3) Nobel Biocare Letter - (Page 4) Nobel Biocare Letter - (Page 5) Nobel Biocare Letter - (Page 6) Nobel Biocare Letter - (Page 7) Nobel Biocare Letter - (Page 8) Nobel Biocare Letter - (Page 9) Nobel Biocare Letter - (Page 10) Nobel Biocare Letter - (Page 11) Nobel Biocare Letter - (Page 12)
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