Ömer Görduysus

A comparison of three rotary systems and hand instrumentation technique for the elimination of Enterococcus faecalis from the root canal.

The aim of this study was to compare the in vitro reduction of a bacterial population in a root canal by mechanical instrumentation using three rotary systems and hand instrumentation technique. The root canals contaminated with a suspension of Enterococcus faecalis were instrumented using ProTaper, K3, HeroShaper and K-file hand instrumentation technique. Later the root canals were sampled. After serial dilutions, samples were incubated in culture media for 24 h. Bacterial colonies were counted and the results were given as number of colony-forming units per millilitre. The results showed that all the canal instrumentation systems reduced the number of bacterial cells in the root canals. Statistically, ProTaper instruments were more effective in reducing the number of bacteria than the other rotary files or hand instruments.

Antimicrobial effects of root canal medicaments against Enterococcus faecalis and Streptococcus mutans.

AIM To compare the antimicrobial activities of Activ Point (Roeko, Langenau, Germany), Calcium Hydroxide Plus Point (Roeko, Langenau, Germany), calcium hydroxide, 1% chlorhexidine gel and bioactive glass (S53P4) against Enterococcus faecalis and Streptococcus mutans. METHODOLOGY One hundred and twenty extracted single-rooted human teeth were used. After removing the crowns, root canals were prepared by using the Protaper rotary system. Following autoclave sterilization, root canals were incubated at 37 °C with E. faecalis ATCC 29212 and S. mutans RSHM 676 for 1 week. The specimens, which were divided into five treatment groups for each microorganism according to the intracanal medicament used, were tested in 10 experimental runs. In each experimental run, 10 roots were included as treatment, one root as positive control and one root as sterility control. Sterile paper points were utilized to take samples from root canals after the incubation of teeth in thioglycollate medium at 37 °C for 1 week. Samples taken from teeth by sterile paper points were inoculated onto sheep blood agar, and following an overnight incubation, the colonies grown on sheep blood agar were counted and interpreted as colony-forming units. Results were tested statistically by using Kruskal-Wallis and Conovers nonparametric multiple comparison tests. RESULTS CHX gel (P < 0.001 and P < 0.001), Activ Point (P = 0.003 and P = 0.002) and Ca(OH)₂ (P = 0.010 and P = 0.005) were significantly more effective against E. faecalis than that of Ca(OH)₂ Plus Point and bioactive glass, respectively. On the other hand, compared with Ca(OH)₂ , CHX gel (P < 0.001), and Activ Point (P < 0.001), bioactive glass (P = 0.014) produced significantly lower colony counts of S. mutans. When compared with the positive control, treatment with Ca(OH)₂ Plus Point (P = 0.085 and P = 0.066) did not produce significantly lower colony counts of E. faecalis and S. mutans, respectively. CONCLUSIONS Compared with the medicaments having an antimicrobial effect because of their alkaline pH, the medicaments containing chlorhexidine were effective against both E. faecalis and S. mutans.

Spontaneously healed root fractures: two case reports.

We report on two undiagnosed horizontal root fractures of two maxillary right central incisors in two different patients caused by dental trauma which occurred several years ago. These fractures were discovered during a routine full-mouth radiographic examination. While, in case one, the fracture was located in the middle-third of the root, it was in the cervical-third of the root in case two. The fractured teeth were observed to have healed spontaneously without any sign or symptom, and tested as vital to electric pulp test.

Effectiveness of a new canal brushing technique in removing calcium hydroxide from the root canal system: A scanning electron microscope study

Aim: To evaluate the effectiveness of Canal Brush technique removal Ca(OH)2 from the root canal system using Scanning Electron Microscope (SEM). Materials and Methods: Eighteen teeth were instrumented up to #40 and dressed with Ca(OH)2. Ca(OH)2 was removed with master apical file (MAF) (Group 1, n:6) and CanalBrush technique (Group 2, n:6). Six teeth served as positive and negative controls. The roots were splited in the buccolingual direction and prepared for SEM examination. Two examiners evaluated the wall cleanliness then statistical analysis was performed by Mann-Whitney U and Friedman tests. Results: Differences in cleanliness were observed between Group 1 and Group 2 in the apical thirds (P=0.002). In the coronal and middle thirds, there were no differences between the two groups. Conclusions: It is essential to re-instrument the root canal walls using instrumentation techniques while irrigating with NaOCl and EDTA combination. The Canal Brush technique results in the packing effect of the Ca(OH)2 through to the apex.

Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

Cytotoxic effect of endodontic irrigants in vitro.

Background Cytotoxicity of root canal irrigants is important due to their close contact with host tissues. The aim of this study was to assess the cytotoxic effect of NaOCl 3%, Chx 2%, and MTAD on rat periodontal ligament fibroblasts, at 0.1 and 100 μl/mL, using WST-1 colorimetric method. Material/Method Rat ligamental fibroblasts were exposed to the irrigants and their viability was assessed after 1, 24, 48, and 72 h. The measurements were determined using WST-1 assay, using a micro ELISA reader. Results At 100 ml/L all 3 irrigants were strongly cytotoxic, although CHX was less so than NaOCl and MTAD. At the 0.1 ml/L concentration, NaOCl and MTAD were only moderately cytotoxic, whereas Chx was highly deleterious to cell viability at all time points. There was a significant influence of the dilution rate of the substance, because the odds ratio for cell viability being over 50% was increased 51 times between the 100 ml/L and 0.1 ml/L dilutions. Conclusions It seems that irrigating solutions should be used at lower concentrations to enhance cell viability.

Effects of preparation techniques on root canal shaping assessed by micro-computed tomography.

Background Root canal shaping without any procedural error is of the utmost preference. Therefore, the purpose of this study was to use micro-computed tomography to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files. Material/Methods Sixty extracted upper second premolars were selected and were divided into 2 groups of 30. Before preparation, all samples were scanned by micro-CT. Then, 30 teeth were prepared with stainless steel files and the remaining 30 with ProTaper rotary files. Canal transportation and centering ability before and after root canal shaping were assessed using micro-CT. The amount and direction of canal transportation and the centering ratio of each instrument were determined in the coronal, middle, and apical parts of the canal. The 2 groups were statistically compared using one-way ANOVA. Results ProTaper rotary files gave less transportation (p<0.001) and better centering ability (p<0.00001) compared with stainless steel files. Conclusions The manual technique for preparation of root canals with stainless steel files produces more canal transportation, whereas rotary files remain more centered in the canal.

A comparison of different irrigation systems and gravitational effect on final extrusion of the irrigant.

Background The aim of this study was to compare manual needle irrigation (MNI), RinsEndo (RE), and passive ultrasonic irrigation (PUI), and assess the effect of gravity on extrusion from the apex in vitro. Material and Methods The distobuccal roots of molars were used and the canals were instrumented up to F2. Teeth were mounted on models, which permitted visualization and manipulation of the apices for necessary procedures. The models were placed in articulator to simulate the jaw. Six groups (G) were formed as: G1, G2 and G3 represented mandibular positioning of teeth and were irrigated with MNI, RE, and PUI, respectively, while G4, G5, and G6 represented maxillary positioning of teeth and were also irrigated in same sequence. Prior to the final irrigation, 72 cube-shaped foam pieces covered with aluminum foil were weighed and the values were recorded as the initial weights. The cubes were then placed on the apical part of each sample. Final irrigation was performed with distilled water and the cubes were weighed again to determine their final weight. Data were analyzed using Kruskal-Wallis and Mann-Whitney U post-hoc test (p<0.05). Results Irrespective of the irrigation technique used, the amount of irrigant extruded from the apex showed a statistically significant difference related to the effect of gravity (p<0.05). There was no statistically significant difference between irrigation methods (p>0.05). When the irrigation systems were compared to examine the effect of gravity, the significant difference was found between G2 and G5 (p<0.05). Conclusions Within the limitations of this study, MNI and PUI were found to be reliable irrigation systems. Caution should be exercised when using RinsEndo. Key words:Final irrigation, manual needle irrigation, passive ultrasonic irrigation, RinsEndo.

An evaluation of antimicrobial efficiency of endo-Fill root canal sealant and filling material

The antimicrobial efficiency of Endo-Fill root canal sealant and filling material was microbiologically evaluated. The zones of inhibition around the Endo-Fill by agar diffusion method were measured. Staphylococcus aureus, Streptococcus faecalis, Streptococcus pyogenes, Escherichia coli, Candiada albicans, and Pseudomonas aeruginosa were used as the selected microorganisms. No zone of inhibition was seen around the Endo-Fill in any of the examples.

In vitro comparison of cytotoxicity of four root canal sealers on human gingival fibroblasts.

The goal of this in vitro study was to evaluate the relative biocompatibility of four endodontic sealers on the cell culture of the human fibroblast through cytotoxicity. Materials and Methods: In this study four endodontics sealers was used GuttaFlow (Roeko)silicone based sealer, AH plus (De Tray-DENTSPLY) epoxy resin based, Apexit (Vivadent) calcium hydroxide based and Endorez (Ultradent) methacrylate based sealer. Sealers were tested on primary cell lines of human gingival fibroblasts. Experiments were preformed in laboratories of Hacettepe University of Ankara, Turkey and Faculty of Dentistry, University of Sarajevo, Bosnia and Herzegovina Cytotoxicity was determinate using WST-1 assay. Results: Results were analyzed by SPSS 19 program. Kolgomorov-Smirnov test, Shapiro-Wilk and descriptive statistics also were used, as well as Kriskall-Wallis, ANOVA test and T- test. According to our results all four sealers showed different cytotoxicity effects on human gingival fibroblast cell culture, but all of them are slightly cytotoxic. Conclusions: According to results of this study it can be concluded: all four sealers showed different cytotoxicity effects on primary cell lines of human gingival fibroblasts, but all of them are slightly cytotoxicity.