Pulpitis on 45 and a necrotic 46

From: Maarten Meire To: ROOTS Sent: Friday, March 26, 2010 7:40 AM Subject: [roots] necrotic 46 Young lady with pulpitis on 45 and a necrotic 46 with history of abcess formation. Large buccal swelling, lots of caries. First removed all restorations and caries. Buildup with GI (Fuji II). Snapped off an S1 in the ML canal during the first visit. Second visit: reduction of buccal swelling but no complete resolution yet. Put calcium again. Third visit OK. Was able to bypass the instrument and complete the instrumentation. Note the periapical healing over the 4,5 months between first and last session! - Maarten

Maarten, a great case! Congratulations! The fractures of S1 are chasing me from some time! I've treated a vital case, which I could have finish in single visit...but NO!!! I've fractured S1 in palatal canal in tooth 2.7? According to you what was the cause of the fracture? For my fractured instruments I blame only metal fatigue - because I use always same ammount of pressure (meaning I don't force the instruments, they lead their way). Thank you for sharing the case! Have a nice week!- Bojidar Very sexy shape as always Maarten ;) S1 is the most often fractured instrumentand by my colleagues and nevertheless everyone keeps on using it!! Don't u think a pre-Race would do the same job with much less risk of separation? - Amir Regarding the pre-Race, I think it should not be compared to the S1 but to Sx, since its length is the same (19mm) and it is not designed to go to full WL. So the pre-race would not exactly do the same job as the S1 (which cuts to length) but surely with less risk of separation. - Maarten Come on! That's placebo! the tip is iso 17 with 2% conicity. it's its middle third which is actively working.And the breakage often results becos we wanna impose the "S1" shape to canals which are relucatant receiving it or for we're trying to pass the huge S1 coronal mass through an early curve? es-tu d'accord Maarten? - Amir Hello, Amir! Allow me to disagree about the S1! The working part is its coronal part, so if you use it to WL you simply can't pass the coronal part of the instrument trough a severe curve! And the middle and the apical parts of S1 are flexible enough to negotiate any curvature that can be instrumented with rotary NiTi files. So form me the S1 is the most "universal" instrument that can be combined with any system on the market! And I can't think of any other instrument that has all the features of S1.- Bojidar Dear Mrs Smith, I just broke an instrument in your rootcanal but u shouldn't worry since it's a computer-designed instrument , made in a unique nickel-TITANIUM alloy, with variable taper and by the way , it's universal! - Amir Amir Actually I read and unpublished study that was compelling with a good study design showing that the S1 breaks at the highest frequency of all the Protaper rotary files (aside from the Sx which I don’t remember being studied) . The S2’s are much more fracture resistant. The F1’s are also weak but not as bad as the S1’s You can prevent breakage by being very careful with the S1’s and F1’s and not using them unless you can use them safely S1’s are a high separation risk and there is unpublished evidence suggesting that - Terry Hello, Amir! I don't think your sarcasm is very funny and want to ask you - Have you broken any files ever?! Now tell me that they all were S1...and one more thing - how do you tell your patients that you've broken an insrument! And I said for me i'ts the most universal and convinient, I do not want to argue with anybody! have a nice day! - Bojidar Hi Bojidar, I didn't wanna brush up on a sensitive spot... I wasn't actually refering to ur post which I hadn't actually read! I'm not on roots to make fun of people but to discuss with them As u know Protaper is now called Protaper "Universal" and it was this that I was refering to. have a nice day too. - Amir I understand now! Sorry for my spicy post, I rushed to write it! No hard feelings, because I also want to discuss endo - that;s how the truth is born! - Bojidar