History of Endodontics aae/abe



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Does CaOH2 Kill Bacteria?


Yes


  1. Sjogren – 7 day CaOH2 eliminated 100% intracanal bacteria




  1. Shuping/Trope 2000 – >7 day CaOH2 (avg 25 days) eliminated 92.5% intracanal bacteria (vs. 62% with instrumentation S1-S4 + 1.25% NaOCl alone)




  1. Safavi – CaOH2 inactivates LPS (gram – endotoxin)




  1. Baik – CaOH2 inactivates E. faecalis LTA (gram + endotoxin)




  1. Bystrom/Sundqvist – Bacteria rapidly repopulate the canal without intracanal medicament. Negative culture following instrumentation + NaOCl + EDTA + CaOH2.



Does CaOH2 Kill Bacteria?


Yes


  1. Law 2004Review - CaOH2 remains the best medicament available to reduce residual microflora beyond instrumentation effort.




  1. Mickel 2003 JOE – Thin mix more effective antibacterial than thick mix




  1. Vera/Siqueira 2012 JOE – 2 visit w/ CaOH2 =  Bacterial counts in main canal, dentinal tubules, isthmuses, apical ramifications, lateral canals (DIAL) = Improved histobacteriologic status




  1. Xavier/Martinho/Oliveria 2013 JOE – 2 visit w/CaOH2 were more effective at reducing bacterial endotoxins (LPS) than 1 visit protocols (98% vs. 86%)



Does CaOH2 dissolve tissue?


YES

  1. Hasselgren 1988– CaOH2 completely dissolved necrotic porcine muscle tissue in 12 days. Tissue pretreated with CaOH2 prior to 0.5% NaOCl treatment dissolved in 60-90 mins vs. No complete dissolution at 12 days for tissue treated with NaOCl alone. CaOH2 causes swelling of the tissue and increases surface area for dissolution (synergistic)




  1. Turkun – Pretreatment with CaOH2 enhanced tissue dissolving efficacy of 0.5% NaOCl to the level achieved with 5% NaOCl. CaOH2 causes tissues to swell and become more accessible to the NaOCl.




  1. Wadachi 1998Bovine teeth, SEM analysis of remaining pulpal tissue: NaOCl >30 s, CaOH2 -7 days showed significantly lower debris scores compared to shorter time intervals; Combination of NaOCl + CaOH2 significantly enhanced the tissue dissolution effect compared to either NaOCl or CaOH2 alone (Synergistic effect)

How do you place CaOH2?


  1. Sigurdsson/Madison 1992 – Compared CaOH2 placement techniques. Lentulo spiral > Calasept syringe + #25 finger plugger > #25 k-file CCW rotation for quality (density) and length of CaOH2 within canal (MB canal)



Does CaOH2 have an effect on the apical seal?


  1. Porkaew 1990 – CaOH2 medicated teeth demonstrated less apical leakage (dye) than non-medicated teeth. This may be due to temporary occlusion of dentinal tubules by the CaOH2 paste or incorporation into the sealer.




  1. Kontakiotis/Wu/Wesselink 1997 – CaOH2 decolors methylene blue dye used in apical leakage studies. Compared apical leakage using fluid tranport model and dye leakage model. CaOH2 had less leakage in only the dye leakage model, calling into question the use of this model for analysis of leakage




  1. Van der Sluis/Wu/Wesselink 2007 – The negative impact of CaOH2 remnants on long term apical seal and leakage has not been evaluated

What is the optimal time for CaOH2 mixture?





  1. Hosoya 2001Optimal peak pH (periapical tissues): Aqueous mixture (CaOH2 powder/distilled H2O) - 14 days; CaOH2 powder alone - 49 days; Time required for opt. intracanal CaOH2 activity is at least 2 weeks



Does residual CaOH2 affect Sealer setting?

YES

  1. Margelos/Lambrianidis 1997Effect of CaOH2 on ZOE cement/sealers: CaOH2 preferentially interacts w/ Eugenol (rapid set), inhibiting ZnO-Eugenol chelate formation and leaving eugenol in set product; Brittle and Granular; Poor cohesion w/ destruction of sealer layer adj to CaOH2





  1. Hosoya 2004 – Effect of CaOH2 on various sealers: ZOE, Ketac-Endo, Sealapex. Significant reduction in working time, Faster setting time, and Increased film thickness occurred. Did not evaluate chemical rxns.

Can CaOH2 be completely removed from the canal?


NO

  1. Lambrianidis/Margelos 1997– In vitro. Considerable amounts of CaOH2 remain on canal walls/apical region following irrigation/filing methods; Filing/15% EDTA/2.25% NaOCl most effective at removing residual CaOH2




  1. Kenee 2006 – In vitro. Mesial canals Mandibular molars; MAF Rotary file or PUI (5.25% NaOCl) significantly more effective at removing CaOH2 (3-4% remaining) than Irrigation alone: 5.25% NaOCl; 5.25% NaOCl + 17% EDTA (19-20% remaining)




  1. Van der Sluis/Wu/Wesselink 2007 – In Vitro. CaOH2 + Artifical groove in apical canal. Compared removal techniques: PUI w/ 2% NaOCl, PUI w/ H2O, and syring delivery 2% NaOCl. PUI w/ 2% NaOCl significantly more effective at removing CaOH2 (63%) vs. PUI w/H2O (6.7%) or NaOCl only (16.7%).
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