Davut Çelik

Comparative study of removal of current endodontic fillings.

The aim of the present study was to assess the removability of canal fillings performed by using current methods during re-treatment with rotary instruments. Seventy-two freshly extracted human anterior teeth with single straight root canals were instrumented with Mtwo rotary files. The teeth were randomly divided into 4 obturation groups of 18 specimens each as follows: group 1, Resilon and Epiphany; group 2, GuttaFlow obturation system; group 3, EndoTwinn obturation system; group 4, gutta-percha with AH Plus sealer. The filled canals were re-treated by using Mtwo-Retreatment instruments and Mtwo instruments. The time required to remove the obturation material was recorded. After splitting the roots, the amount of residual filling material on the canal walls was imaged and measured with image analyzer software. Statistical analysis was accomplished by Kruskal-Wallis and Mann Whitney U tests for the analysis of root canal cleanliness. There was no statistically significant difference among the 4 filling techniques regarding the amount of residual material in the apical, middle, and coronal thirds and inside the whole canal area (P > .05). Regarding the mean time of re-treatment, the fillings performed by using GuttaFlow and EndoTwinn methods were removed much more quickly compared with the other 2 methods (P < .001). It was observed that the fillings performed with the above canal filling methods were removed in a similar fashion with rotary instruments during re-treatment.

Efficacy of several techniques for the removal of calcium hydroxide medicament from root canals

AIM To compare the efficacy of several techniques for the removal of calcium hydroxide (Ca(OH)(2)) from root canals. METHODOLOGY The root canals of 24 freshly extracted human mandibular premolars were prepared with ProTaper rotary instruments. The teeth were sectioned longitudinally along the length of the instrumented canals. The roots were subsequently reassembled with wires. After Ca(OH)(2) was placed into the canals, four techniques were used for its removal. In Group I, the teeth were irrigated with 5 mL of 2.5% NaOCl. Group II was treated in the same manner as Group I, but 5 mL of 17% EDTA was used in addition to NaOCl. In Group III, the teeth were irrigated with 5 mL of 2.5% NaOCl and agitated by an ultrasonic unit. In Group IV, the teeth were irrigated with 5 mL of 2.5% NaOCl and a CanalBrush was used to remove the Ca(OH)(2) . The roots were disassembled and digital photographs were taken. Measurements of residual Ca(OH)(2) were performed as percentages of the overall canal surface area. The data was analysed with one-way ANOVA with post hoc Tukey test. RESULTS Significantly less residual material was obtained with a CanalBrush and passive ultrasonic agitation of NaOCl than the other groups (P < 0.05). There was no significant difference between syringe delivery of NaOCl and NaOCl+EDTA (P > 0.05). CONCLUSIONS None of the techniques removed the Ca(OH)(2) dressing completely. CanalBrush and ultrasonic agitation of NaOCl were significantly more effective than irrigant-only techniques.

Comparative Study of 6 Rotary Nickel-Titanium Systems and Hand Instrumentation for Root Canal Preparation in Severely Curved Root Canals of Extracted Teeth

INTRODUCTION Some improvements have been developed with new generations of nickel-titanium (NiTi) rotary instruments that led to their successful and extensive application in clinical practice. The purpose of this in vitro study was to compare the root canal preparations performed by using GT Series X and Twisted File systems produced by innovative manufacturing process with Revo-S, RaCe, Mtwo, and ProTaper Universal systems manufactured directly from conventional nitinol and with stainless steel K-Flexofile instruments. METHODS The mesiobuccal root canals of 140 maxillary first permanent molars that had between 30°-40° curvature angle and 4- to 9-mm curvature radius of the root canal were used. After root canal preparations made by using GT Series X, Twisted File, Revo-S, RaCe, Mtwo, and ProTaper Universal NiTi rotary systems and stainless steel K-Flexofile instruments, transportation occurred in the root canal, and alteration of working length (WL) was assessed by using a modified double-digital radiographic technique. The data were compared by the post hoc Tukey honestly significant difference test. RESULTS NiTi rotary systems caused less canal transportation and alteration of WL than K-Flexofile instruments (P < .05). There was no significant difference between NiTi rotary system groups at any levels (P > .05) except 2.5 mm from the WL. At this level ProTaper Universal system caused significant canal transportation (P < .05). CONCLUSIONS GT Series X and Twisted File rotary systems produced with innovative process were concluded to shape the curved canals to result in minimal canal transportation, similar to Revo-S, RaCe, Mtwo, and ProTaper Universal rotary systems manufactured by traditional methods.

Comparison of the sealing ability of three filling techniques in canals shaped with two different rotary systems: A bacterial leakage study

OBJECTIVE This study compared the sealing ability of 3 current filling techniques in root canals shaped with 2 different rotary systems. STUDY DESIGN Eighty human extracted mandibular premolars were divided randomly into 2 similar groups of 40 each and instrumented with either ProTaper (Dentsply Maillefer, Tulsa, OK; group A) or Mtwo (VDW; Antaeos, Munich, Germany; group B) rotary systems. Each group was divided into 3 subgroups (n = 10) and 2 control groups (n = 5). Canals were filled either with the tapered single-cone technique (SC; subgroups A1 and B1), with lateral condensation (LC; subgroups A2 and B2), or warm vertical compaction (WVC; subgroups A3 and B3). AH Plus was used as a root canal sealer in all groups. Samples were sterilized in an ethylene oxide sterilizer for 12 hours. The apical 3-4 mm of the roots were immersed in brain-heart infusion culture medium with phenol red indicator within culture chambers. The coronal access of each specimen was inoculated every 48 hours with a suspension of Enterococcus faecalis. Bacterial leakage was monitored every 24 hours for 8 weeks. The data obtained were analyzed using a chi-squared test, and P was set at .05. RESULTS In group A, 70% of the specimens filled with SC (subgroup A1), 50% of the specimens filled with LC (subgroup A2), and 20% of the specimens filled with WVC (subgroup A3) leaked. There was no statistically significant difference between the subgroups (P > .05). In group B, bacterial leakage was observed in 50% of SC samples (subgroup B1), 40% of LC samples (subgroup B2), and 50% of WVC samples (subgroup B3). There was no statistically significant difference between subgroups B1, B2, and B3 (P > .05). There was also no statistically significant difference between group A and group B (P > .05). CONCLUSION Filling with SC, LC, and WVC techniques in canals treated with ProTaper or Mtwo rotary instruments showed similar levels of sealing efficacy.

The restoration of a maxillary central incisor fracture with the original crown fragment using a glass fiber‐reinforced post: a clinical report

This report describes an esthetic, conservative, and economical alternative restoration technique for a fractured central incisor using the patients own tooth crown piece and a bondable reinforcement glass fiber. Although the long-term durability of this adhesive post core restoration remains unknown, it remains successful after 1 year.

Effect of Unintentionally Extruded Mineral Trioxide Aggregate in Treatment of Tooth with Periradicular Lesion: A Case Report

INTRODUCTION This case report describes the effect of unintentionally extruded mineral trioxide aggregate (MTA) into periradicular lesions and tissues on the prognosis of periradicular healing in maxillary left central incisor with periradicular lesion. METHODS A 17-year-old girl with a large periradicular lesion from the apices of her maxillary left central to lateral incisors was referred. Tooth #9 had an open apex, but tooth #10 was normal. Conservative root canal treatment was performed to tooth #10. The apical third of the canal of tooth #9 was filled with MTA as an apical plug because of open apex. During this procedure, a radiograph was taken, and it showed an excessive extrusion of MTA into the periradicular lesion. The remaining canal space was filled with gutta-percha and AH Plus sealer by using a lateral condensation technique. RESULTS At follow-up examinations, the tooth was asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic surgical intervention. CONCLUSIONS The results of this case showed that complete periapical healing is possible despite the extrusion of the MTA. This might be due to biologic properties of the MTA. Even so, extrusion of the filling material is not advocated.

Treatment of horizontal root fractures using a triple antibiotic paste and mineral trioxide aggregate: A case report

This case report describes the treatment of a horizontal root fracture in a maxillary central incisor (tooth #8) using a triple antibiotic paste and mineral trioxide aggregate. A nonsurgical endodontic treatment was performed to a coronal root canal fragment of tooth #8. During the treatment procedure, 1% sodium hypochlorite solution was used for irrigation and a triple antibiotic paste was used as an intracanal medicament. The coronal part of the canal was obturated with mineral trioxide aggregate totally. At follow-up examination after 12 months, the tooth was asymptomatic and radiographically showed repair of the fracture region. Healing was achieved without any need for further interventions.

An in vitro comparison of apically extruded debris using three rotary nickel-titanium instruments

Background/purpose The aim of this in vitro study was to compare the amount of extruded debris using three rotary nickel-titanium (NiTi) instruments (ProTaper Universal, Mtwo, and BioRaCe). Materials and methods Sixty freshly extracted human single-rooted mandibular premolars were randomly assigned into three groups of 20 teeth each. The root canals were instrumented using ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), Mtwo (VDW, Munich, Germany), or BioRaCe (FKG Dentaire, La-Chaux-de-Fonds, Switzerland) NiTi instruments. Debris and liquid extruded from the apical foramen during instrumentation were collected into tubes. Then, the liquid inside the tubes was removed by lyophilization, and the mean weight of the remaining debris was calculated for each group and compared. Data were then statistically analyzed using one-way ANOVA and post-hoc Tukeys tests. Results There were significant differences in the amount of debris extruded among all groups (P Conclusion According to this study, all instrumentation techniques apically extruded debris through the apical foramen. However, the BioRaCe instruments induced less extruded debris than the ProTaper Universal and Mtwo rotary systems.

Bond strength of calcium silicate-based sealers to dentine dried with different techniques.

Objective: To assess the influence of various canal-drying techniques on the push-out bond strength between radicular dentine and both MTA Fillapex and iRoot SP sealers. Materials and Methods: Eighty extracted single-root teeth were instrumented with ProTaper Universal rotary instruments to a size F4. The teeth were randomly assigned to 1 of 4 groups as follows: group 1, excess fluid in the canals was removed using a Luer vacuum adapter; group 2, the canals were dried with a single paper point; group 3, the canals were dried with 3-5 paper points, and group 4, the canals were rinsed with 95% ethanol and then dried with 3-5 paper points. In each group, the specimens were subgrouped according to root canal sealer into either subgroup A (MTA Fillapex) or subgroup B (iRoot SP sealer). Horizontal sections (thickness 1 ± 0.1 mm) were obtained from each specimen and a push-out test was performed using a universal testing machine at a crosshead speed of 1 mm/min on root slices. Statistical analysis was done using the Kruskal-Wallis test and Dunns test for pair-wise comparisons. p < 0.05 was considered statistically significant. Results: Canals dried with only 1 paper point and obturated with the iRoot SP sealer (subgroup 2B) showed significantly higher bond strengths to the root canal wall compared to all other subgroups (p < 0.05), except for subgroup 1B (p > 0.05). Conclusions: The canal-drying technique influenced the adhesive bond strength between calcium silicate-based root canal sealers and the root canal wall.

Comparison of influence of different manufacturing methods on the cleaning efficiency of rotary nickel–titanium files

The purpose of this study was to evaluate and compare cleaning effectiveness of TwistedFile, GT series X, Revo‐S, RaCe, Mtwo, and ProTaper Universal rotary files in curved canals. Seventy mesiobuccal canals of extracted human first maxillary molars were divided into seven groups of 10 samples each. Canals were prepared with six nickel–titanium (NiTi) rotary systems and manual K‐Flexofile. Irrigation was performed with 2 mL 2.5% NaOCl solution after each file, and 5 mL 2.5% NaOCl was used for the final flush. After the roots were split longitudinally, the presence of debris and smear layer was visualized using scanning electron microscopic photomicrographs taken at coronal, middle, and apical third. Mean scores for debris and the smear layer were calculated and statistically analyzed for significance between groups using the Kruskal–Wallis nonparametric analysis of variance (P < 0.05) and Mann–Whitney U test (P < 0.001). There was no significant difference among the groups in terms of debris and smear layer scores (P > 0.05). Without considering the preparation method used, while no statistically significant difference was found between the coronal third and the middle third (P > 0.05), higher amount of debris and smear layer were found in apical third (P = 0.001). The new generation of NiTi rotary files including the Twisted File and GT Series X presented similar cleaning effectiveness compared with traditionally ground NiTi rotary files. Microsc. Res. Tech. 76:231–236, 2013.