Dental Press

[ original article ] The persistence of different calcium hydroxide paste medications in root canals: an SEM studystudies that found the removal of calcium hydroxidebaseddressings extremely difficult or even impossible.13-21,23The use of pure Ca(OH) 2as intracanal dressing,although reported in some studies, 18,28 seem to beboth impractical clinically in narrow canals and notdesirable, since ionic diffusion would be minimal. Inthe present study, it was used merely as a control, toallow comparison with other formulations. Althoughthe lower persistence in the root canal system reportedin the results, the use of such medicationwithout a vehicle does not seem to be suitable ordesirable clinically.Propylene glycol or polyethylene glycol used asvehicles provide a viscous consistency to the paste,which facilitates the insertion in the root canal, leadingsome authors to prefer this formulation. The slowrelease of ions and resorption by the surroundingtissues are also among the qualities advocated. 5,11,12However, results suggest that removal of viscouspastes may be more difficult than other formulations,causing an excess of medication remaining at the apicallevel of the root canal. Similar findings were foundby Lambrianidis et al 15 and Nandini et al, 18 but usingcommercially available pastes based on methylcelluloseor silicone oil, respectively. Other authors foundno differences regarding Ca(OH) 2medication persistenceassociated to different vehicles. 23,28Association of Ca(OH) 2with saline solution showedto be easier to remove from the root canals than propyleneor polyethylene glycol, but still persisted ingreater amounts when compared to glycerin used asvehicle. Other studies may be necessary to understandthe reasons of the lower amounts of Ca(OH) 2found onthe Ca(OH) 2+ glycerin group (GIV).Conclusions1. Pure calcium hydroxide based medications orits association to glycerin allows an easier removalfrom the root canal.2. The association of Ca(OH) 2with polyethyleneglycol or propylene glycol 400 determines ahigher persistence of the medication inside thecanal prior to obturation.3. None of the intracanal medications could betotally removed from the root canals.© 2011 Dental Press Endodontics 80Dental Press Endod. 2011 apr-june;1(1):77-81