DIAG IM3 - Page 126

15Internal 3 Dental Equipment Fixation & Instrumentation www.vetinst.com Locking Screws Locking Screws - Star Drive The angular security of locking plate systems depends on a rigid interface between screw and plate. This is achieved by the use of interlocking threads. Locking Screw Star Drive 3.5mm Threaded systems are the most common. The modulus of bone and stainless steel differs greatly and the ideal screw thread for one will not suit the other. Stainless steel demands fine threads whereas bone needs a relatively coarse thread. If we use a fine thread in the plate and a coarse thread in the bone, when the head of screw engages the plate, the screw moving faster through the bone than the plate would have the effect of pulling the plate towards the bone. This is exactly what we do not want. Some systems compromise by using the same thread in both screw head and bone plate. VI screws are an exact fit for standard locking plates but utilise the Star Drive rather than Hex drive. At Veterinary Instrumentation and in the industry Standard Locking Screw the problem is solved by some ingenious engineering. The threads on the head of our screws are fine as required but have a twin start. The threads taper down the head as a double helix. The pitch (the distance between the tips of the threads) of each individual fine thread is the same as the threads on the bone screw but because of the double helix the number of threads per millimeter of locking thread is double that of the bone screw giving the fine threads required for metal on metal. The screw moves through the bone at the same rate as it moves through the plate maintaining the relative positions of both bone fragment and plate. LOCKING SCREW STAR DRIVE 3.5MM USE 2.7MM PILOT PLUS DRILL SLEEVE LS35STAR10 LS35STAR12 LS35STAR14 LS35STAR16 LS35STAR18 LS35STAR20 LS35STAR22 LS35STAR24 LS35STAR26 LS35STAR28 LS35STAR30 LS35STAR32 LS35STAR34 LS35STAR36 LS35STAR38 LS35STAR40 LS35STAR42 LS35STAR44 LS35STAR45 LS35STAR46 LS35STAR48 LS35STAR50 LS35STAR52 LS35STAR54 LS35STAR56 LS35STAR58 LS35STAR60 LSDG35 H090104 SHLS35 There is an additional benefit of the double helix. As the screw head approaches the plate a single start thread may have to wait 360 degree rotation before the threads start to engage. In the 3.5 screw this might mean that the plate is pushed around one millimeter before the head of the screw engages. With a twin start thread the screw head will engage within 180 degrees of contact. Locking Screw Sets Available with either Hex (3.5mm only) or Star Drive Head. Sets discounted by over 5% from component price. 3.5 Set includes: Locking 3.5 Screw Star Drive10mm Locking 3.5 Screw Star Drive 12mm Locking 3.5 Screw Star Drive 14mm Locking 3.5 Screw Star Drive 16mm Locking 3.5 Screw Star Drive18mm Locking 3.5 Screw Star Drive 20mm Locking 3.5 Screw Star Drive 22mm Locking 3.5 Screw Star Drive 24mm Locking 3.5 Screw Star Drive 26mm Locking 3.5 Screw Star Drive 28mm Locking 3.5 Screw Star D &fR3А6r2R67&Wr7F"G&fR3&А6r2R67&Wr7F"G&fR3FА6r2R67&Wr7F"G&fR3fА6r2R67&Wr7F"G&fR3А6r2R67&Wr7F"G&fRCА6r2R67&Wr7F"G&fRC&А6r2R67&Wr7F"G&fRCFА6r2R67&Wr7F"G&fRCVА6r2R67&Wr7F"G&fRCfА6r2R67&Wr7F"G&fRCА6r2R67&Wr7F"G&fRSА6r2R67&Wr7F"G&fRS&А6r2R67&Wr7F"G&fRSFА6r2R67&Wr7F"G&fRSfА6r2R67&Wr7F"G&fRSА6r2R67&Wr7F"G&fRcА6r67&WrG&wVFRf"2P"vBG&2R6r67&Wv&*3"ダ*3"ダ*32cP*32cP*3Bp*3Bp*3B@*3R#*3RCP*3Rs*3b#0*3bC*3bs@*3r*3r#`*3rS*3rsp*30*30*3#*3S@*3`*3Sp*3#*3#c*3#c0*3#"c`*3SB*3rsP*3CB#6rVr7F"G&fP2"#B#"#fW#CGC"S7S"SФ6r67&Ww2BR6rVw2"r6WB6VFW32bӆBfW#G33&73BC6r67&Ww2BR6rVw2"B6WB6VFW32bӆBfW#G33&73BC6r67&Ww2BR6rVw2ࠥW6RF&FV7B6rW2GW&r6FW&rࠤ4r45$U~(4UE033T@33U5D$@3#u5D$@3#E5D$@3#5D$@2RWG&fR6r67&Wr6W@2R7F"G&fR6r67&Wr6W@"r7F"G&fR6r67&Wr6W@"B7F"G&fR6r67&Wr6W@"7F"G&fR6r67&Wr6W@*3S3P*3S3P*3#BP*3#BP*3#BP4rTr5D.(E$dP53U5D 5#E5D 5#5D 6rVrf"33U5D"67&Ww0*3#@6rVrf"3#s#E5D"b3#C#E5D"67&Ww0*3#@6rVrf"3#5D"67&Ww0*3#@