Reverse rotary instrumentation in the apical third of the root canal system: An scanning electron microscope analysis

The aim of the present study was to evaluate the efficacy of reverse rotary instrumentation in disinfection of the root canal at the apical third and qualitative confirmatory analysis using the scanning electron microscope (SEM). Subjects and Methods: Sixty single-rooted mandibular premolars were instrumented up to Protaper rotary file size F2 and contaminated with a known species of Enterococcus faecalis (ATCC 29212). The samples were then divided into three groups; Group 1: Experimental group-irrigation by agitation of 1% NaOCl with reverse rotary instrumentation; Group 2: Negative control-no irrigation; and Group 3 positive control-irrigation with 1% NaOCl using a 30-gauge needle. The colony forming units of all the groups were checked. SEM analysis of the samples was focused on the apical third to confirm the absence of E. faecalis biofilms. The data obtained were statistically analyzed by the Fisher's exact test and Pearson's Chi-square test. Results: Group I and III showed significant reduction in the growth of E. faecalis (P ≤ 0.001). SEM confirmed dense bacterial colonies in the Group II consistent with biofilm formation and reduction in bacterial colonies in Group I and II. Conclusion: Agitation with reverse rotary instrumentation in the apical third of the root canal along with 1% sodium hypochlorite proved effective in disinfection of the apical third of the root canal, which was further confirmed by scanning electron microscopic analysis. Hence, it can be used as an adjunct during rotary instrumentation in efficient cleansing of the root canal system in the apical third of the root canal system.

Apical Third Horizontal Root Fractures in Anterior.

Horizontal root fractures are a type of traumatic dental injury. Horizontal root fractures are classified as apical third, middle third, and cervical third of the root based on the fracture line and on the degree of dislocation of the coronal fragment. The prognosis of the tooth depends on the patient’s age, stage of root growth, mobility of the coronal fragment and diastasis of the fragments. Proper clinical and radiographic examination should be done to reveal apical root fractures. Hence, the treatment plan can be decided depending on the type of fracture and extent of fracture line. This review was conducted to evaluate the apical third horizontal root fractures in order to determine the appropriate therapy.

A Comparison of the irrigation systems in calcium hydroxide removal / 대한치과보존학회지

The purposes of this study were to compare the efficacy of irrigation systems by removing a calcium hydroxide (Ca(OH)2) paste from the apical third of the root canal and the effect of the patency file. Sixty single rooted human teeth were used in this study. The canals were instrumented by a crown-down manner with .04 taper ProFile to ISO #35. Ca(OH)2 and distilled water were mixed and placed inside the root canals. The teeth were divided into 6 groups according to the root canal irrigation system and the use of patency file as follows: group 1 - conventional method; group 2 - EndoActivator(R); group 3 - EndoVac(R); group 4 - conventional method, patency; group 4 - EndoActivator(R), patency; group 6 - EndoVac(R), patency. All teeth were irrigated with sodium hypochlorite. After the root canal irrigation, the teeth were split in bucco-lingual aspect. Percentage of the root canal surface coverage with residual Ca(OH)2 until 3 mm from working length was analyzed using Image Pro Plus ver. 4.0. Statistical analysis was performed using the One-way ANOVA, t-test and Scheffe's post-hoc test. Conventional groups had significantly more Ca(OH)2 debris than EndoActivator(R), EndoVac(R) groups. There was no significant difference between EndoActivator(R) and EndoVac(R) groups. Groups with patency file showed more effective in removing Ca(OH)2 paste than no patency groups, but, it was no significant difference. This study showed that EndoActivator(R) and EndoVac(R) systems were more effective in removing Ca(OH)2 paste from the apical third of the root canal than conventional method.