Fuat Ahmetoglu

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.

Quality of different gutta-percha techniques when filling experimental internal resorptive cavities: a micro-computed tomography study.

The purpose of this ex vivo study was to determine the quality of root fillings in experimental internal resorptive cavities filled using cold lateral condensation (CLC), vertical condensation and Thermafil techniques. Forty-five extracted maxillary canine teeth were selected. After root canal instrumentation, the roots were sectioned horizontally and experimental internal resorption cavities were prepared. The root sections were re-approximated with a luting agent and randomly assigned to three groups (n = 15) to be filled using CLC, vertical condensation and Thermafil, respectively. Assessment of obturation quality in the internal resorptive cavity was performed using a desktop X-ray micro focus computed tomography scanner, and the percentage of gutta-percha (GP), sealer and voiding was calculated for each specimen. Data were statistically analysed using non-parametric tests, with P < 0.05 denoting a statistically significant difference. Vertical condensation filled 96.25 ± 8.31% of the total artificial cavity, and was superior to CLC (63.20 ± 16.87%) and Thermafil (59.26 ± 18.47%). The mean percentage of voids was 3.75 ± 8.31% in the vertical condensation group, 37.09 ± 17.13% in the CLC group and 41.06 ± 18.60% in the Thermafil group. We conclude that obturation of experimental resorption cavities is significantly better when using vertical condensation than when using other GP-based techniques.

Effect of different light sources in combination with a light‐transmitting post on the degree of conversion of resin composite at different depths of simulated root canals

AIM The aim of this study was to evaluate the degree of conversion (DC) of composite resin at different depths of simulated immature root canals using light-transmitting plastic post (LTPP) and three different light sources. METHODOLOGY Composite resin was packed into 60 black plastic cylinders 12mm in length with 4mm internal diameters to simulate immature root canals. LTPPs were inserted into half of the simulated canals and the other half acted as controls. Both the simulated canals with LTPPs and the controls were divided into three groups of 10, and each group was cured using either a quartz-tungsten-halogen (QTH), light-emitting diode (LED), or plasma arc (PAC) curing unit. Specimens were sectioned in three horizontally 24h after curing to represent cervical, middle, and apical levels. DC for each section of composite resin was measured using a Fourier transform infrared spectrophotometer, and data were analyzed using three-way anova and Tukey tests. RESULTS At the cervical level, no significant differences were found between specimens cured using different light sources or between specimens with and without LTPPs (P>0.05). However, DC was significantly higher in specimens with LTPPs than in those without LTPPs at both the middle and apical levels (P<0.05). The mean DC of all specimens with LTPPs was significantly higher than that of specimens without LTPPs (P<0.05). PAC unit showed lower DC than QTH and LED units at both the middle and apical levels; however, the differences were not statistically significant (P > 0.05). CONCLUSIONS The results of this study suggest that the use of a LTPP increased the DC of composite resin at the middle and apical levels of simulated immature root canals, but that DC was independent of type of light source.

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.

Comparative analysis of three different filling techniques and the effects of experimental internal resorptive cavities on apical microleakage

Objectives: The aim of this study was to evaluate the sealing abilities of three different gutta-percha techniques in experimentally defective roots (EDR) and non-defective roots (NR). Materials and Methods: Sixty canine teeth were divided into six groups of ten; Group 1, NR + cold lateral condensation (CLC); Group 2, EDR + LC; Group 3, NR + BeeFill; Group 4, EDR + BeeFill; Group 5, NR + Thermafil; and Group 6, EDR + Thermafil. Apical leakage was measured using a computerized fluid filtration meter with a laser system. Results : Statistical analysis revealed that the CLC demonstrated more microleakage in the EDR than in the NR (P < 0.01). Thermafil demonstrated more microleakage in the NR than in the EDR (P < 0.01). No statistically significant differences were found between the BeeFill groups (P > 0.05). Conclusions: The results of this study indicate that internal resorptive cavities can affect the apical sealing properties of different root canal filling techniques, with Thermafil ensuring the lowest apical microleakage.

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.

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.

Comparison of the sealing ability of different glass ionomer cements as root-end filling materials

Objectives: The purpose of this study was to compare the sealing ability of different glass ionomer cements (GIC) as root-end filling (RF) materials. Materials and Methods: One-hundred and eleven extracted human canines were cleaned and prepared using a rotary nickel titanium files with crown-down technique. All the teeth were filled with gutta-percha and then the apical third of each root was resected perpendicularly to the long axis direction. After, root-end cavity was prepared using a round bur. The specimens were randomly divided into 7 groups of 15 samples, filled with one of the test materials (Ionofil, Ketac Molar Quick Aplicap, Argion Molar AC, Photac Fil Quick Aplicap, Fuji II LC Capsule, Dyract Extra, Glasiosite Caps) and were stored at 37°C and 100% humidity for 7 days. 1-week later, apical parts of roots of 10 ± 0.05 mm were attached to the computerized fluid filtration device. The data obtained were analyzed using an ANOVA and post hoc Tukey′s tests (P ≤ 0.05). Results: Statistical analysis indicated that RF with Argion molar AC (reinforced GIC) had the least micro-leakage of all and whereas Ketac Molar Quick Aplicap (conventional GIC) showed highest apical leakage than the other groups. Conclusion: This present study has shown that none of GICs, which used as a RF material unable to prevent apical leakage exactly and Argion Molar AC is used as a RF material among current GICs better than others.

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.

Effect of salivary contamination on micro-tensile bond strength of self-etch adhesives systems after bonding procedure

Aims: The purpose of this study was to evaluate the effect of saliva contamination on the micro-tensile bond strength (μTBS) of two self-etching (SE) adhesive systems (Clearfil SE Bond, Clearfil S3 Bond). Materials and Methods: Flat occlusal dentin surfaces were created on 12 extracted human third molar teeth. The two bonding systems and resin composite (Spectrum® TPH® 3) were bonded to the dentin under six surface conditions: Group 1: Tooth samples were randomly divided into three equal subgroups. Clearfil SE 1: This was a control group in which dentin was not contaminated with the saliva (primer/bonding/composite). Clearfil SE 2: Contaminated once (primer/bonding (cured)/saliva/rinsing/drying/primer/bonding/composite). Clearfil SE 3: The samples were contaminated 2 times (primer/bonding (cured)/saliva/rinsing/drying/primer/bonding (cured)/saliva/rinsing/drying/primer/bonding/composite). Group 2: The procedures for Group 2 were similar to Group 1 but did not contain a primer stage. Tooth samples were randomly divided into three equal subgroups (Clearfil S3 1, 2, and 3). After 24 h, the teeth were prepared for microtensile bond testing and tensile bond strength was measured (1 mm/min). The data were calculated as megapascal (MPa) and analyzed using the one-way ANOVA and Tukey′s post-hoc test (P < 0.05). Results: The μTBS of the Clearfil S3 3 subgroup was statistically higher than that of the Clearfil S3 2 subgroup and Clearfil S3 1 subgroup. There were no significant statistical differences in the μTBSs between the Clearfil S3 2 subgroup and the control subgroup. There were no statistical differences in μTBSs among the Clearfil SE subgroups. Conclusion: μTBS is not affected adversely from one or two saliva contamination after the bonding procedure.