Neslihan Simsek

Effectiveness of different irrigation systems on smear layer removal: A scanning electron microscopic study

Objectives: To evaluate effectiveness of the apical negative pressure irrigation (EndoVac), passive ultrasonic irrigation (PUI), and conventional needle irrigation (CI) systems on smear layer (SR) removal. Materials and Methods: Sixty single-rooted canines were prepared using NiTi rotary files and subjected to different irrigation regimens: EndoVac with NaOCl (Group 1) or NaOCl/EDTA (Group 2); PUI with NaOCl (Group 3) or NaOCl/EDTA (Group 4); CI with NaOCl (Group 5) or NaOCl/EDTA (Group 6). The roots were split longitudinally. SEM images were taken to evaluate the amount of residual SR. Results: In Groups 1, 3, and 5, there was no removal of SR (P > 0.05). The coronal thirds within Groups 2, 4, and 6 were cleaned completely, but the middle and the apical thirds was achieved partially or completely (P > 0.05). Conclusion: Regardless of which irrigation system was used, the use of NaOCl alone failed to remove the SR. In NaOCl/EDTA combination groups, the SR was removed partially or completely and no statistical significance. This study demonstrated that in order to remove the SR should be used EDTA solution for final irrigation in the root canal, regardless of the technique in each of the three.

3D Analysis of D-RaCe and Self-Adjusting File in Removing Filling Materials from Curved Root Canals Instrumented and Filled with Different Techniques

The aim of this study was to compare the efficacy of D-RaCe files and a self-adjusting file (SAF) system in removing filling material from curved root canals instrumented and filled with different techniques by using microcomputed tomography (micro-CT). The mesial roots of 20 extracted mandibular first molars were used. Root canals (mesiobuccal and mesiolingual) were instrumented with SAF or Revo-S. The canals were then filled with gutta-percha and AH Plus sealer using cold lateral compaction or thermoplasticized injectable techniques. The root fillings were first removed with D-RaCe (Step 1), followed by Step 2, in which a SAF system was used to remove the residual fillings in all groups. Micro-CT scans were used to measure the volume of residual filling after root canal filling, reinstrumentation with D-RaCe (Step 1), and reinstrumentation with SAF (Step 2). Data were analyzed using Wilcoxon and Kruskal-Wallis tests. There were no statistically significant differences between filling techniques in the canals instrumented with SAF (P = 0.292) and Revo-S (P = 0.306). The amount of remaining filling material was similar in all groups (P = 0.363); all of the instrumentation techniques left filling residue inside the canals. However, the additional use of SAF was more effective than using D-RaCe alone.

Assessment of the biocompatibility of mineral trioxide aggregate, bioaggregate, and biodentine in the subcutaneous tissue of rats

OBJECTIVE The objective of this study was to evaluate the tissue inflammation caused by three endodontic repair materials. MATERIALS AND METHODS The materials included micro mega-mineral trioxide aggregate (MM-MTA), bioaggregate (BA), and biodentine (BD), which were implanted into the subcutaneous tissue of rats. The tissue samples for histological examination were prepared. The infiltration of lymphocytes and macrophages into the tissue was examined to assess the inflammatory response. RESULTS Lymphocyte infiltration: A significant increase was detected in the MM-MTA and BA groups on the 7th and 14th days as compared with the control (7th day P=0.0001, 14th day P=0.0176). There was no difference between the groups on the 45th day (P=0.1730). Lymphocyte infiltration had decreased over time in all groups. Macrophage infiltration: There was a significant increase by the 7th day in the test groups as compared to the control group (P=0.007). However, there was no difference between the experimental groups on the 14th (P=0.2708) and 45th (P=0.1291) days. CONCLUSION While MM-MTA and BA showed a similar biocompatibility, BD was more biocompatible than MM-MTA and BA in the 1 st week of the experiment. However, there was no difference between the materials at the end of the 45th day. MM-MTA, BA, and BD can be considered suitable endodontic repair materials.

Biocompatibility of a new epoxy resin-based root canal sealer in subcutaneous tissue of rat.

Objective: The objective was to evaluate the subcutaneous biocompatibility of two root canal sealers. Materials and Methods: Thirty female rats were distributed into two groups of 15 animals. Each received subcutaneous dorsal implants: Silicone tubes filled with AH Plus or Obtuseal. After the 11 th , 14 th , and 45 th days, tissues were collected for biopsy and fixed and processed for histologic evaluation. Observations of the cellular inflammatory components, such as lymphocytes and macrophages, were made. The data were analyzed using Kruskal-Wallis and Connover tests (P < 0.05). Results: By the 7 th day, lymphocyte infiltration increased in both groups (P = 0.0104). However, macrophage infiltration increased only in the AH Plus group (P = 0.0011). By the 14 th and 45 th days, lymphocyte and macrophage infiltrations were reduced. At the end of the experimental period, no statistically significant differences were found between the AH Plus group and the Obtuseal group (P > 0.05). Conclusion: After 45 days, Obtuseal yielded a satisfactory tissue reaction; it was biocompatible when tested in subcutaneous rat tissue. On the basis of the obtained results, it was concluded that Obtuseal root canal sealer caused a satisfactory tissue reaction as AH plus, because it was biocompatible when tested in the subcutaneous tissue of rats.

Heat conductive properties of set root canal sealers

Abstract Objective. The aim of this study was to examine the thermal conductivity of five different root canal sealers in vitro. Materials and methods. Sealapex, AH Plus, AH 26, Endomethasone and RoekoSeal root canal sealers were examined. These materials were prepared in accordance with the manufacturers instructions and applied to standard molds. Three samples of each material were prepared. The samples were kept for 5 days under 37°C conditions. Measurements were taken using a heat conduction unit (P.A. Hilton Ltd. Stockbridge, Hants, UK). The thermal conductivity coefficient was calculated for each sample using the Fourier equation. Coefficients were analyzed statistically by the Kruskal–Wallis test. Results. Significant differences were found for thermal conductivity between some materials (p < 0.05). The conductivity coefficient of AH Plus was found to be higher than those of the other materials (p < 0.05). No statistically significant differences were found between AH 26 and RoekoSeal (p > 0.05) and the conductivity coefficients of these sealers were found to be lower than those of the other materials (p < 0.05). No statistically significant differences were found between Sealapex and Endomethasone (p > 0.05) and the conductivity coefficients of these sealers were found to be lower than that of AH Plus but higher than those of RoekoSeal and AH26 (p < 0.05). Conclusions. The results showed that root canal sealers functioned as thermal insulators and had different heat-conductive properties that depended on their composition.

Comparative evaluation of root canal preparations of maxillary first molars with self‐adjusting file, reciproc single file, and revo‐s rotary file: A micro‐computed tomography study

This study was aimed to use micro-computed tomography (μ-CT) to evaluate the canal shaping properties of three nickel-titanium instruments, Self-Adjusting File (SAF), Reciproc, and Revo-S rotary file, in maxillary first molars. Thirty maxillary molars were scanned preoperatively by using micro-computed tomography (μ-CT) scans at 13,68 μm resolution. The teeth were randomly assigned to three groups (n = 10). The root canals were shaped with SAF, Reciproc, and Revo-S, respectively. The shaped root canals were rescanned. Changes in canal volumes and surface areas were compared with preoperative values. The data were analyzed using Kruskal-Wallis and Conovers post hoc tests, with p < .05 denoting a statistically significant difference. Preoperatively canal volumes and surface area were statistically similar among the three groups (p > .05). There were statistically significant differences in all measures comparing preoperative and postoperative canal models (p = 0.0001). These differences occurred after instrumentation among the three experimental groups showed no statistically significant difference for volume (p > .05). Surface area showed the similar activity in buccal canals in each of the three techniques whereas no statistically significant difference was detected among surface area, the SAF, and the Revo-S in the palatal (P) canal. Each of three shaping system showed the similar volume activity in all canals, but SAF and Revo-S provided more effectively root planning in comparison with Reciproc in P canal.

Endodontic treatment of hypertaurodontism with multiple bilateral taurodontism

The term taurodontism is derived from the Latin word tauros, for “bull,” and the Greek term odus, for “tooth,” or “bull tooth.” Taurodontism is a morpho-anatomical developmental anomaly, which is seen infrequently in teeth only. It is characterized by a deficiency in the constriction at the cement-enamel junction, with lengthened pulp chambers and apical displacement of the pulpal floor. This gives the tooth a quadrilateral or cylindrical look. This report presents a case of multiple bilateral taurodontism and the successful endodontic treatment of the tooth that had hypertaurodontism. A male patient was referred to the endodontic clinic with decayed left maxillary first molar. Hypertaurodontism was confirmed after clinical and radiographic examination. Panaromic X-rays revealed that all of the patients molar teeth were taurodontic. Taurodontism offers challenges to the practitioner during shaping and disinfection and at the time of filling the root canals.

Determination of trace elements in kidneys, livers and brains of rats with sealer implants by ICP-MS

ABSTRACT Following root canal treatment, sealers may contact periapical tissue. The purpose of this study was to evaluate the systemic toxic effects of epoxy resin-based sealers (AH Plus and Obtuseal). Inductively coupled plasma-mass spectrometry (ICP-MS) was used to measure levels of trace elements (beryllium, magnesium, aluminium, calcium, chromium, arsenic and lead) in the brain, kidney and liver of rats. Twenty sterilized polyethylene tubes were then filled with AH Plus and Obtuseal and implanted into the dorsal subcutaneous tissue of 10 rats; three unoperated animals were used as a control group. After 45 days, the rats were sacrificed by cervical dislocation following anaesthesia, and brains, kidneys and livers were removed from all experimental animals. ICP-MS analysis was used to determine levels of trace elements. Data were analysed using Kruskal–Wallis and Connover post hoc tests. No significant differences were found in aluminium and calcium levels, but brains, kidneys and livers showed significantly higher amounts of magnesium and chromium than the corresponding controls. In the kidney and liver samples, arsenic levels were found to be higher than in the control group. Lead was detected at higher levels only in liver samples from the AH Plus group. Beryllium was not detected in any organ. It was concluded that AH Plus and Obtuseal release minimal quantities of trace elements when in contact with subcutaneous tissue, and further studies are needed to understand the systemic effects of these materials.

Multidisciplinary treatment approach for horizontal root fractures

The aim of this case report is to present a multidisciplinary treatment plan for horizontal root fracture of maxillary anterior teeth that resulted from trauma. A 16-year-old male presented a horizontal root fracture in the middle-third of teeth 11 and 21. Dislocated tooth fragments were repositioned using a composite splint technique. Follow-up examinations revealed the teeth lost vitality after trauma. Separated tooth fragments were removed by a surgical operation and then reattached using fiber post and resin cement. Teeth were replanted into the alveolar socket and splinted after root canal treatment. After 1 year of follow-up examinations, this comprehensive treatment was observed to be successful both clinically and radiographically. Horizontal root fractures can be treated successfully by extraoral reattaching of fractured segments and intentional replantation of teeth after root canal treatment.

A comparison of the bond strength of different adhesive systems to dentin contaminated with chloroform

Aim: The purpose of this study was to evaluate the microtensile bond strengths of five different bonding agents to dentin contaminated with chloroform which cleaning the remnants of the root canal sealer in coronal access cavities of teeth. Materials and Methods: A total of 30 extracted human mandibular molar teeth were used for study. Teeth were sectioned with diamond bur to expose the superficial dentin. AH Plus as a root canal sealer was placed to exposed dentin surface. Teeth were stored at least for 5 min motionless for sealer set. More of sealer on the surface of teeth was taken with the help of cotton pellets. Dentin surface was treated with 0.1 mL of chloroform which was kept for 1 min. After that, surfaces of teeth were flushed with distilled water and dried. Teeth were separated randomly into five groups and Clearfil SE Bond, Futura Bond M, Adper Easy Bond, Clearfil S3 Bond, and Optibond FL bonding agents were applied according to manufacturer′s instructions. The specimens were sectioned parallel blocks approximately 1 mm thickness and 1 mm width. The specimens pasted apparatus and subjected to microtensile testing device with a crosshead speed of 1 mm/min. Connection surface of all samples was measured after the end of the test process. The connection types of surfaces were examined under a light microscope magnification Χ10. Results: There was no statistically significant difference between the Optibond FL and Adper Easy Bond. However, Adper Easy Bond gave higher binding than the other tested materials. There was no statistically difference among Optibond FL, Clearfil S3 Bond, and Clearfil SE Bond. Conclusions: Many endodontically treated teeth are lost due to poor restorative treatment of teeth. Endodontic treatment procedures will affect bonding agents, so it could result in failure of the restoration.