Effect of gravity and capillarity on human saliva penetration in coronally unsealed obturated root canals

The purpose of this study was to evaluate the effect of gravity and capillarity on penetration of human salivary bacteria into the entire length of obturated root canals, and to demonstrate the dye penetration configuration. Fifty single-rooted premolars were decoronated, prepared to a standardized length of 15 mm, instrumented, and randomly divided into two groups [A and B] of 25 teeth each. Each group consisted of experimental [15 samples] and negative and positive controls [five samples each]. The experimental groups were obturated with gutta-percha and root canal sealer. The positive control groups were obturated with a single cone of gutta-percha and root canal sealer. The outer surfaces [except for the apical 2 mm] were covered with two layers of nail varnish. An apparatus containing Brain Heart Infusion broth was designed, in which the teeth were placed. The samples in Group A were placed upside down, while Group B was placed normally. The coronal portions of the samples were placed in contact with fresh saliva. The number of days required for bacteria to penetrate the entire length of canals was determined. The samples were then immersed in India ink to determine the dye penetration configuration. Data were analyzed using Student's Mest. The extent of dye penetration was significantly greater in Group B compared to Group A, and they were in a pattern rather than linear form. Gravity and capillarity insignificantly affected bacterial leakage. Although gravity and capillarity did not affect bacterial penetration when applied to the coronal access of endodon-tically treated teeth, it seems that they can promote penetration of India ink into the canal after the bacterial test on the same tooth

Comparison of antimicrobial efficacy of IKI and NaOCI irrigants in infected root canals: An in vivo study

Effective debridement of the root canal system with chemical irrigants prior to obturation is the key to long-term success of endodontic therapy. The purpose of this study is to compare the antibacterial activity of 2.5% sodium hypochlorite [NaOCI] and 2% iodine potassium iodide [IKI] solutions as intracanal disinfectant in infected root canals during one-visit endodontic treatment procedure. Thirty single-rooted teeth with necrotic pulps in 27 patients were selected according to specific inclusion/exclusion criteria and divided into two random groups. In group I, canals were irrigated with 2.5% NaOCI during instrumentation and in group II canals were initially irrigated with sterile saline during biomechanical preparation and then exposed to a 5-minute final irrigation with 2% IKI. Bacterial samples were taken before treatment [Si], and at the end of treatment [S[2]]. Mann-Whitney U test was used for analysis. Bacteria were present in all initial samples. NaOCI was able to significantly reduce the number of colony forming units [CPU] from Si to S[2] in approximately 90% of canals. Only 15% reductions in CPUs occurred after irrigation/instrumentation in group II; this degree of disinfection was not statistically significant. According to this study, although root canal irrigation with 2.5% NaOCI could not eradicate all bacteria within the canals; it was significantly superior in comparison with 2% IKI use