Mehmet Tanriver

Variations in cyclic fatigue resistance among ProTaper Gold, ProTaper Next and ProTaper Universal instruments at different levels

AIM To compare the cyclic fatigue resistance of ProTaper Gold (PTG, Dentsply Tulsa Dental Specialities, Tulsa, OK, USA), ProTaper Next (PTN, Dentsply Tulsa Dental Specialities) and ProTaper Universal (PTU, Dentsply Tulsa Dental Specialities) instruments at different levels. METHODOLOGY A total of 72 files were used to evaluate the cyclic fatigue of PTU (F2), PTN (X2) and PTG (F2) at 5 mm (n = 12) and 8 mm (n = 12) from the tip in 3-mm-radius steel canals with a 60° angle of curvature. The time to fracture was recorded. The Kolmogorov-Smirnov test was used to assess the normality of the samples distribution, and the statistical analysis was performed using the independent sample t-test (P < 0.01). RESULTS Significant differences were found amongst the instruments 5 mm from the tip (P < 0.01). The PTG files had the highest CF resistance, and the PTN files displayed greater CF resistance than the PTU files. No significant differences were found between the PTG and PTN files 8 mm from the tip (P > 0.01). The PTG and PTN files demonstrated greater CF resistance than the PTU files (P < 0.01). CONCLUSIONS The PTG instruments were the most resistant 5 and 8 mm from the tip; however, at 8 mm, there was no difference between the PTG and PTN instruments. The PTU files had the lowest CF resistance at all levels.

Fracture resistance of simulated immature teeth after apexification with calcium silicate-based materials

Objective: To compare the fracture resistance of simulated immature teeth filled with an apical barrier of mineral trioxide aggregate (MTA), Biodentine, and calcium-enriched mixture (CEM). Materials and Methods: Fifty-two single-rooted human maxillary central incisors were used. For standardization, the teeth were sectioned 6 mm above and 9 mm below the cementoenamel junction to simulate immature apex. Simulations of roots into immature apices were carried out using 1.5 mm diameter drills. The specimens were then randomly divided into three experimental groups (n = 13) and one control group (n = 13). In experimental groups, MTA, Biodentine, and CEM were placed to apical 4 mm of the simulated immature roots. The samples were stored at 37° C and 100% humidity for 1 week. A load was applied on the crown of all teeth at 135° to their long axis until fracture. The data were analyzed using one-way analysis of variance and Tukey post-hoc tests. Results: No statistically significant differences were found among MTA, CEM, and Biodentine (P > 0.05), and these groups demonstrated higher fracture resistance than control group (P < 0.05). Conclusions: Using any of the MTA, Biodentine, and CEM as an apical plug and restoring with fiber post and composite resin increases the fracture resistance of immature teeth.

Fracture strength of roots instrumented with three different single file systems in curved root canals

Objective: The aim of this study was to compare the fracture strength of roots instrumented with three different single file rotary systems in curved mesial root canals of maxillary molars. Materials and Methods: Curvatures of 25°-35° on mesial roots of 60 maxillary molar teeth were sectioned below the cementoenamel junction to obtain roots 11 mm in length. The roots were balanced with respect to buccolingual and mesiodistal diameter and weight. They were distributed into three experimental groups and one control group (no instrumentation) (n = 15): Reciproc rotary file (R25, VDW, Munich, Germany), WaveOne Primary rotary file (Dentsply Tulsa Dental Specialties, Tulsa, UK) and OneShape (Micro-Mega, Besancon, France) rotary file. Vertical load was applied until fracture occurred. Data were statistically analyzed using one-way analysis of variance test (P < 0.05). Results: The mean fracture load was 412 ± 72 Newton (N) for the control group, 395 ± 69 N for the Reciproc group, 373 ± 63 N for the WaveOne group and 332 ± 68 N for the OneShape group. The fracture load differences among three experimental groups were not statistically significant (P > 0.05.) Whereas, the fracture loads of control and OneShape groups were significantly different (P = 0.012). Conclusions: Fracture resistance of the roots instrumented with WaveOne and Reciproc file systems were similar to the control group whereas it was observed that OneShape rotary file systems enhance the fracture strength of standardized curved roots when compared with the control group.

Comparison of cyclic fatigue resistance between different NiTi instruments with 4% taper

The aim of this study was to make a comparison between the cyclic fatigue (CF) resistance of F360, twisted files (TF), FlexMaster (FM) and RaCE instruments with 4% taper. A total of 40 instruments were evaluated 8 mm from the tip. A stainless steel block with a simulated canal of 1.5 mm diameter, and a 60° angle of curvature was tested using CF testing. One‐way ANOVA and posthoc Tukeys test (P < 0.05) were used. The F 360 files showed the highest CF resistance while the TF files had greater CF resistance than the FM and RaCE (P < 0.05). There was no significant difference between the FM and RaCE (P > 0.05). F360 instruments with a double S cross‐section had the highest CF resistance among the group. The TF led the NiTi rotary files to be more resistant to fatigue than the FM and RaCE instruments. Microsc. Res. Tech. 79:345–348, 2016.

In Vitro Evaluation of Microleakage and Microhardness of Ethanolic Extracts of Propolis in Different Proportions Added to Glass Ionomer Cement.

OBJECTIVE To evaluate the effect of ethanolic extracts of propolis (EEP) addition in different proportions to glass ionomer cement (GIC) on microleakage and microhardness of GIC. STUDY DESIGN The cement was divided into four groups: one using the original composition and three with 10%, 25%, and 50% EEP added to the liquid and then manipulated. For microleakage assessment, sixty primary molars were randomly divided into four groups (n=15). Standard Class II cavities were prepared and then filled with EEP in different proportions added to GICs. Microleakage test was performed using a dye penetration method. The data were analyzed using one-way ANOVA and Mann-Whitney U tests (α = 0.05). Disc shaped specimens were prepared from the tested GIC to determine Vickers hardness (VHN). The data were analyzed using one-way ANOVA and post hoc Tukey test (α = 0.05). RESULTS There were no statistically significant differences between the groups in terms of microleakage (p > 0.05). There were statistically significant differences between the VHN values of groups (p < 0.05). Increasing addition of EEP to GIC statistically significantly increased VHN value of GIC (p < 0.05). CONCLUSIONS The addition of EEP to GIC increased the microhardness of the GIC and did not adversely affect the microleakage. Thus, it might be used during routine dental practice due to its antibacterial properties.

Effects of Different Instrumentation Techniques on Calcium Hydroxide Removal From Simulated Immature Teeth

The aim of this study was to evaluate the effectiveness of endodontic instrument systems in the removal of calcium hydroxide [Ca(OH)(2)] from simulated immature teeth. The root canals of 106 human single-rooted teeth were shaped with ProTaper rotary files up to an F5 file size. Simulation of roots with immature apices was carried out using size 4 green 1.5-mm diameter Unicore drills. A non-setting Ca(OH)(2) was injected into each root canal and inserted into the working length using lentulo spiral, after which cotton pellets were placed over canal orifices. The apical and coronal side of the roots were then sealed with glass ionomer cement and light cured. Specimens were stored in distilled water for 3 months at 37 °C. After 3 months, the temporary coronal seal was removed and the samples were randomly divided into five experimental groups according to the method used for Ca(OH)(2) removal (ProTaper, Reciproc, OneShape, WaveOne, and Manual) (n = 20), one positive control group (n = 3) and one negative control group (n = 3). The amount of remaining Ca(OH)(2) in the canal walls was measured under a stereomicroscope at 30× magnification. The data were analyzed using Kruskal-Wallis test and Mann-Whitney U test at a significance level of 0.05. Positive and negative control groups were found to be statistically different from all other groups (p < 0.05). There were no significant differences among the ProTaper, Reciproc, OneShape, WaveOne, and Manual groups (p > 0.05). As a conclusion, none of the techniques completely removed Ca(OH)(2) from simulated immature teeth.

Effectiveness of different irrigation protocols on calcium hydroxide removal from simulated immature teeth after apexification

Abstract Aim: To evaluate the effectiveness of different irrigation solutions and ultrasonic activation of the irrigation solutions on the removal of calcium hydroxide (Ca(OH)2) from the simulated immature root canals after apexification. Materials and methods: One-hundred and one single-rooted teeth were used. The root canals were shaped with ProTaper rotary files up to F5. Simulation of roots with immature apices was carried out using size 4 Unicore drills. An injectable Ca(OH)2 was injected into each root canal, and packed to the working length. Then, cotton pellets were placed over canal orifices, and apical and coronal parts of the roots were sealed with resin-modified glass ionomer cement, and light cured. Specimens were stored in distilled water for 3 months at 37°C. After 3 months, the temporary coronal seal was removed and the samples were randomly divided into: (a) saline (n = 20), (b) ultrasonic activation of saline (n = 20), (c) sodium hypochlorite (NaOCl) (n = 20), (d) ultrasonic activation of NaOCl (n = 15), (e) chlorhexidine digluconate (CHX) (n = 20) and one positive control group (n = 3) and one negative control group (n = 3). The amount of remaining Ca(OH)2 on the canal walls was measured under stereomicroscope with 30× magnification. Comparisons between groups were made by the non-parametric Kruskal-Wallis test and Dunn post-test at a significance level of p < 0.05. Results: There were no significant differences among the saline, ultrasonic activation of saline, NaOCl, ultrasonic activation of NaOCl and CHX (p > 0.05) groups. Conclusions: Irrigation solutions and ultrasonic activation of the irrigation solutions could not completely remove Ca(OH)2 from the simulated immature root canals.

CAD/CAM Endocrown Fabrication from a Polymer-Infiltrated Ceramic Network Block for Primary Molar: A Case Report

OBJECTIVE The aim of this case report is to describe the treatment of a primary molar with a deep carious lesion by pulpotomy and placement of a ceramic endocrown. CLINICAL CASE A 7-year-old male patient with profound caries in tooth number 85 was referred to our clinic and underwent a pulpotomy. As the final treatment in tooth restoration, placement of an endocrown was planned, because little more than half of the tooth structure remained. After an additional request from the patients parents for an advanced and prompt restoration, a computer-aided design/computer-aided manufacturing (CAD/CAM) polymer-infiltrated ceramic network (PICN) block was chosen. A three-dimensional model of the arch was obtained after scanning the dental cast, and the endocrown was designed digitally according to the model. When the design was complete, the endocrown was fabricated with a milling machine. Finally, the endocrown was cemented with self-adhesive resin cement. RESULTS Over the 9-month follow-up period, no pulpal or periradicular pathology was observed on radiographs. Regarding the crown, the marginal fit was excellent, the anatomical form was protected, and no discoloration occurred. CONCLUSION During follow-up, the CAD/CAM PICN block endocrown proved to be a good material for the short- to long-term treatment of a primary tooth. However, more clinical cases and follow-up are required to investigate the long-term effects of antagonistic tooth wear.

Clinical management of a traumatized maxillary central incisor restored with the original fragment using fiber-reinforced post system

This case report describes the management of a supragingivally complicated crown fracture of a maxillary central incisor. A 19-year-old male patient was referred to the Department of Endodontics for the management of his traumatized maxillary incisors. He had no medical disorders and there was no evidence of a periapical pathology in the initial radiograph. The maxillary left central and right lateral incisors had an enamel fracture but were asymptomatic to palpation and percussion tests so it was decided to be treated with a direct composite restoration. Whereas, the right central one was symptomatic and had a supragingivally complicated crown fracture. Therefore, it was medicated with calcium hydroxide dressing for one week. After the root canal treatment was completed, the tooth was restored using a light-transmitting fiber-reinforced post system with the original fragment. There was an excellent satisfaction with using original fractured fragment even after 12 months.

A comparison of different irrigation/agitation methods for the removal of calcium hydroxide medicament from the root canal walls

Aim: To compare the removal efficiency of calcium hydroxide (CH) medicament from the root canal walls with different irrigation/agitation methods. Materials and Methods: Forty human mandibular premolars were selected. Root canals of these teeth were prepared up to F4 file using ProTaper rotary system and then filled with CH. All root specimens were stored at 37΀C and 100% relative humidity for 7 days. Teeth were randomly divided into four different groups (n = 10). For the removal of the medicaments from the canal walls, roots were subjected to the final irrigation/agitation methods used as follows: Conventional syringe irrigation with side-vented needle (Group 1), passive ultrasonic irrigation (PUI; Group 2), manual dynamic agitation (Group 3), and apical negative pressure irrigation (Group 4). The negative control did not receive CH placement. The positive control received the intracanal medication, but no subsequent removal. Roots were split longitudinally into two halves. Digital images of the root canal walls were acquired by a digital camera and assessed for residual amount of medicament. Cervical, middle, and apical third of each canal was assessed by using a scoring system. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey′s multiple comparison tests, at 95% confidence interval (P < 0.05). Results: There were no statistically significant differences between all experimental groups and the negative group in each canal third (P > 0.05). However, there were statistically significant differences between the experimental groups and the positive control (P < 0.05). None of the experimental groups totally removed CH medicaments from root canal walls. Conclusions: In the limitations of this in vitro study, all experimental groups produced similar removal efficiency in terms of canal cleanliness.