The effect of pH of the sodium hypochlorite on smear layer removal

Introduction. Canal irrigation is an important segment of endodontic treatment. The aim of this study was to assess the efficacy of 0.5% NaOCl solutions of different pH values on smear layer removal. Material and Methods. Thirty-two freshly extracted single rooted teeth with gangrenous pulp were used in the study. The samples were divided into four groups of eight teeth in each. Four solutions of 0.5% NaOCl having pH values 5, 7, 9 and 12 respectively, were used during chemomechanical instrumentation with hand instruments and using step back technique. SEM analysis was done to assess the quality of smear layer removal in apical, middle and coronal part of root canal. Presence and quantity of smear layer and detritus was quantified using the scale from 1 to 5. Results. SEM analysis results showed similar results for 0.5% NaOCl solutions of different pH values in root canal cleaning with no statistically significant differences. Conclusion. The most effective cleaning root canal was achieved with 0.5% NaOCl solution of pH 5. Uvod. Irigacija kanala je znacajan segment svakog endodontskog lecenja zuba. Cilj ovog rada je bio da se proveri efekat ciscenja zida kanala korena zuba nakon ispiranja rastvorom od 0,5% natrijum-hipohlorita (NaOCl) razlicitih pH vrednosti. Materijal i metode rada. Kao materijal koriscena su 32 sveze izvadjena jednokorena zuba sa gangrenoznom pulpom. Uzorci su svrstani u cetiri grupe od po osam zuba. Za ispiranje tokom mehanicko-medikamentne obrade tzv. step-back tehnikom i rucnim endodontskim instrumentima primenjena su cetiri rastvora koncentracije od 0,5% NaOCl sa puferovanim rastvorima cija je pH vrednost bila 5, 7 i 9, odnosno nepuferovanim rastvorom pH vrednosti 12. SEM analizom je proveren kvalitet ciscenja zida kanala od razmaznog sloja u apeksnom, srednjem i koronarnom delu kanala korena. Procena zastupljenosti i kolicine razmaznog sloja i detritusa vrsena je ocenjivanjem na skali od 1 do 5. Rezultati. Rezultati SEM analiza su pokazali slicno dejstvo razlicitih pH vrednosti rastvora NaOCl u ciscenju kanala korena zuba bez statisticke znacajne razlike. Zakljucak. Najefikasnije ciscenje kanala korena ostvareno je 0.5% rastvorom NaOCl ciji je pH 5.