ABSTRACT
OBJECTIVE: The aim of this study was to compare the cyclic fatigue resistance at body temperature and phase transformation behaviors of novel Rotate instrument (25.06) with rotating Mtwo (25.06) and reciprocating Reciproc Blue (25.08) and Reciproc (25.08) instruments. MATERIALS AND METHODS: The Rotate, Reciproc Blue, Reciproc, and Mtwo instruments free of visible deformations were collected and tested in a static cyclic fatigue test method, which has a ceramic block containing an artificial canal with 60° angle of curvature and a 5-mm radius of curvature at 37 °C (n = 16). All instruments were operated until fracture occurred, and both time to fracture (TF) and the lengths of the fractured fragments were recorded. TF data was analyzed with one-way ANOVA followed by post hoc Tukey tests and Weibull analysis, and fractured fragment length data were subjected to one-way ANOVA and post hoc Tukey tests (P < 0.05). Two unused instruments from each brand were also subjected to differential scanning calorimetry (DSC) analysis to determine their phase transformation temperatures. RESULTS: The Reciproc Blue instruments showed significantly higher TF values and reliability than the other groups (P < 0.05). Rotate instruments exhibited greater cyclic fatigue resistance than the Reciproc and Mtwo instruments (P < 0.05). No significant difference was detected among the fractured fragment lengths (P > 0.05). The lowest austenite finish temperature was exhibited by the Mtwo, which presented a single transformation peak, followed by the Rotate, Reciproc Blue, and Reciproc instruments which all presented two peaks during transformation. CONCLUSIONS: Cyclic fatigue resistance of instruments manufactured from thermally treated Blue wire instruments was superior to those of the Mtwo and Reciproc, whereas reciprocating the Blue wire showed the highest resistance. CLINICAL RELEVANCE: The present study compared the cyclic fatigue resistance of the novel Rotate instrument with similar instruments manufactured from conventional nickel-titanium, m-wire, and Blue wire at body temperature and reported that Blue-treated instruments exhibited superior cyclic fatigue resistance.
Subject(s)
Dental Instruments , Nickel , Body Temperature , Dental Alloys , Equipment Design , Equipment Failure , Materials Testing , Reproducibility of Results , Root Canal Preparation , Stress, Mechanical , Temperature , TitaniumABSTRACT
OBJECTIVE: The aim of this study was to evaluate the cyclic fatigue resistance of Reciproc and Reciproc Blue by testing in a severe apical curvature at intracanal temperature. MATERIALS AND METHODS: Eighteen Reciproc R25 (25.08) and Reciproc Blue (25.08) instruments were tested in a cyclic fatigue device at body temperature (37 °C) using a stainless steel block with an artificial canal with a curvature angle of 90° and radius of curvature of 2 mm. The number of cycles to fracture (NCF) was calculated. The instruments were examined by differential scanning calorimetry (DSC). The data were analyzed using both Student's t tests and Weibull analysis. RESULTS: The NCF values of Reciproc R25 were significantly lower than Reciproc Blue R25 (P < 0.05). There was no significant difference between the instruments regarding the length of fractured fragments (P > 0.05). CONCLUSIONS: Reciproc Blue R25 instruments displayed significantly higher NCF than Reciproc R25. CLINICAL RELEVANCE: This study reported that novel reciprocating blue wire instruments exhibited higher cyclic fatigue resistance than its precedence M-wire instrument when tested in severely curvatured canals.
Subject(s)
Dental Instruments , Equipment Failure , Materials Testing , Root Canal Preparation , TemperatureABSTRACT
OBJECTIVE: The aim of the present study was to compare the cyclic fatigue resistance of R-Pilot (VDW; Munich, Germany) with ProGlider (Denstply Sirona; Ballaigues, Switzerland) and WaveOne Gold Glider (Denstply Sirona; Ballaigues, Switzerland) glide path instruments. MATERIALS AND METHODS: R-Pilot, ProGlider, and WaveOne Gold Glider instruments were collected (n = 15) and tested in a dynamic cyclic fatigue test device, which has an artificial canal with 60° angle of curvature and a 5-mm radius of curvature. All instruments were operated until fracture occurred, and both time to fracture (TF) and the lengths of the fractured fragments were recorded. Mean and standard deviations of TF and fragment length were calculated for each reciprocating system. TF data and fractured fragment length data were subjected to one-way ANOVA and post-hoc Tukey tests (P < 0.05). Also a Weibull analysis was performed on TF data. RESULTS: The cyclic fatigue resistance values of the WaveOne Gold Glider and R-Pilot were significantly higher than those of the ProGlider (P < 0.05), with no significant difference between them (P > 0.05). Weibull analysis revealed that WaveOne Gold Glider showed the highest predicted TF value for 99% survival rate, which was followed by R-Pilot and ProGlider. Regarding the length of the fractured tips, there were no significant differences among the instruments (P > 0.05). CONCLUSIONS: The reciprocating WaveOne Gold Glider and R-Pilot instruments had significantly higher cyclic fatigue resistance than rotary ProGlider instruments. CLINICAL RELEVANCE: This study reported that novel reciprocating glide path instruments exhibited higher cyclic fatigue resistance than rotating glide path instrument.
Subject(s)
Dental Instruments , Equipment Failure Analysis , Equipment Design , Materials TestingABSTRACT
OBJECTIVE: The objective of this study is to evaluate the clinical performance of direct resin composite restorations placed with different techniques (incremental or bulk) and different flowable linings (conventional or bulk-fill) in endodontically treated teeth. MATERIALS AND METHODS: Forty-seven pair class II (mesio-occlusal or disto-occlusal) composite restorations were placed in 37 patients. In all cavities, Adper Single Bond 2 was used. In one of the cavities of each pair, a conventional flowable composite, Aelite Flo, was applied in approximately 2 mm thick, and the remaining cavity was restored incrementally with GrandioSO. In the second cavity, a bulk-fill flowable composite, x-tra base, was applied in approximately 4 mm thick in bulk increments and the remaining 2-mm occlusal part of the cavity was restored with GrandioSO. All cavities were restored with open-sandwich technique by the same operator. At baseline and after 6-month, 1-, 2-, and 3-year follow-up visits, restorations were evaluated by modified USPHS criteria. RESULTS: At 3-year recall, 33 restorations with Aelite Flo lining and 33 with x-tra base lining were available. Two restorations from each group (6.0 %) were scored as Bravo in terms of surface texture. One restoration's color match from x-tra base group scored as Bravo (3.0 %). All other evaluated criteria were scored as Alfa (100 %) for all restorations. No statistically significant difference between the two groups was found in all evaluated criteria during 3-year period (p > 0.05). CONCLUSION: Bulk-filling technique showed clinically acceptable performance comparable to the incremental technique. CLINICAL RELEVANCE: Restorations placed with bulk-filling technique with x-tra base lining and incremental technique with a conventional flowable lining showed highly clinical performance over 3-year period.
Subject(s)
Composite Resins , Dental Cavity Lining/methods , Dental Restoration, Permanent/methods , Tooth, Nonvital , Adult , Barium Compounds , Bisphenol A-Glycidyl Methacrylate , Dental Cements , Female , Humans , Male , Silicon Dioxide , Treatment OutcomeABSTRACT
UNLABELLED: In this case report, an alternative approach was presented for treatment of coronal fracture including pulp of maxillary central incisor, one of the abutments of an adhesive bridge, by using fiber post and tooth's own fractured component. The patient was referred to our clinic with the complaint of pain from the upper right central incisor and mobility of the adhesive bridge in maxillary anterior segment. It was realized that, the upper right central incisor, one of the abutments of the adhesive bridge, had been fractured at middle thirds of the crown including the pulp chamber. After dismounting the adhesive bridge and completion of the root canal treatment, a fiber post was placed into the fractured tooth. The fractured component, adherent to adhesive bridge retainer, was concorded to the fiber post. The whole structure was cemented with adhesive resin. A 1-mm-wide groove was made along the fracture line and restored with composite resin. The patient was evaluated clinically and radiographically at 12 and 30 months after the treatment. CLINICAL SIGNIFICANCE: Adhesive cementation of fractured component by supporting the remaining tooth structure with a fiber post is an inexpensive and conservative treatment alternative when the fractured component is compatible with the remaining tooth structure in cases of tooth fractures including the pulp chamber at anterior segment.
Subject(s)
Dental Abutments , Denture, Partial, Fixed, Resin-Bonded , Incisor/injuries , Patient Care Planning , Tooth Crown/injuries , Tooth Fractures/therapy , Acid Etching, Dental/methods , Adult , Cementation/methods , Composite Resins/chemistry , Dental Pulp Exposure/therapy , Dentin-Bonding Agents/chemistry , Female , Follow-Up Studies , Humans , Post and Core Technique/instrumentation , Resin Cements/chemistry , Root Canal Preparation/methodsABSTRACT
INTRODUCTION: This study aimed to compare ProGlider (Dentsply Sirona, Ballaigues, Switzerland) and R-Pilot (VDW, Munich, Germany) instruments in terms of their cyclic fatigue resistance using an artificial stainless steel canal showing an abrupt apical curvature, torsional resistance according to the ISO specification, and topographic changes on the instrument surface after glide path management in mesial canals of mandibular first molars with the abrupt curvature selected based on their micro-computed tomographic examination. METHODS: Eighty instruments were used: 40 ProGlider (size 0.16, .02v taper) and 40 R-Pilot (size 0.125, .04 taper) instruments. The cyclic fatigue resistance was tested in a static test model using an artificial canal with an abrupt apical curvature (angle of curvature of 90° and radius of curvature of 2 mm). The torsional resistance test was performed according to ISO 3630-1 specifications. To determine surface topography of the unused and used instruments, mesial root canals of mandibular molars with an abrupt apical curvature were selected to prepare a glide path with either the ProGlider or R-Pilot instrument. An optical profilometer and scanning electron microscopy were used to determine the surface properties. Normally distributed torsional and cyclic resistance data were analyzed using the Student t test, whereas quantitative data obtained by the optical profilometer were analyzed with the Kruskal-Wallis H test with a 5% significance threshold. RESULTS: The R-Pilot showed significantly higher cyclic fatigue and torsional resistance than the ProGlider (P < .05). Angular deflection values were similar between instruments (P < .05). Measurements made from the blade area showed that the surface roughness values of the ProGlider were larger. Cutting blade measurements showed that unused instruments had significantly greater roughness values than used ones (P < .05). Although there was a 14% increase between the blade edge radii of the used and unused R-Pilot instruments, this difference was determined as 61% in ProGlider instruments. CONCLUSIONS: The R-Pilot exhibited greater cyclic fatigue strength than the ProGlider when tested in an artificial canal with an inner diameter of 1.0 mm and an abrupt apical curvature. Torsional resistance of the R-Pilot was higher than the ProGlider, but the angular deflection values were similar. Glide path preparation in a mesial root canal with an abrupt apical curvature did not increase the surface roughness of both instruments but resulted in a greater blade edge radius.
Subject(s)
Dental Instruments , Root Canal Preparation , Equipment Design , Equipment Failure , Humans , Materials Testing , TitaniumABSTRACT
The present study aimed to compare the apically extruded debris produced during glide path preparation using R-Pilot (RP), WaveOne Gold Glider (WGG) and ProGlider (PG) with the subsequent preparation using Reciproc Blue in curved root canals. Mesial roots of mandibular molars with angle of curvature between 25° and 35° were selected (n = 20). The Myers and Montgomery method was used to collect and assess apically extruded debris. The glide path was prepared either manually with K-file, ProGlider, R-Pilot or WaveOne Gold Glider. Manual preparation group produced the highest amount of apically extruded debris (P < 0.05), while all groups caused debris extrusion. There were no significant differences among the extruded debris caused by RP, PG and WGG groups (P > 0.05). Apically extruded debris produced by engine-driven reciprocational or continuous rotational single file glide path instruments was similar, whereas manual glide path preparation was associated with the greatest amount of extruded debris.
Subject(s)
Dental Pulp Cavity , Root Canal Preparation , Gold , Molar , Tooth RootABSTRACT
OBJECTIVE: Widespread use of rotary nickel-titanium systems has caused manufacturers to produce gutta-percha cones that match the taper of the canals prepared with these systems. Obturations with these cones may provide 3-dimensional obturation of the root canal in less time. The aim of this study was to use a fluid filtration method to compare the apical sealing ability of matched-taper single-cone, Thermafil and lateral condensation obturations. MATERIALS AND METHODS: Sixty-six extracted human lower premolar teeth were instrumented to size F3 with ProTaper instruments. The teeth were divided into 3 groups and obturated with matched-taper single-cone, Thermafil and lateral condensation techniques. AH Plus was used as a sealer. Six teeth were used as positive and negative controls. A fluid filtration system was used to evaluate the apical seal. Measurements were made at 2-minute intervals for 8 minutes and the average of these values was recorded. One-way analysis of variance test was used for statistical analysis. RESULTS: Mean leakage values for the lateral condensation, single-cone and Thermafil groups were 0.49 +/- 0.37 microL min(-1), 0.39 +/- 0.24 microL min(-1) and 0.44 +/- 0.25 microL min(-1), respectively. The difference between the groups was not statistically significant (p > 0.05). CONCLUSIONS: The apical sealing ability of matched-taper single-cone obturation was comparable with that of lateral condensation and Thermafil techniques.
Subject(s)
Dental Leakage/classification , Gutta-Percha/chemistry , Root Canal Filling Materials/chemistry , Root Canal Obturation/methods , Dental Bonding , Dental Marginal Adaptation , Dental Pulp Cavity/anatomy & histology , Epoxy Resins/chemistry , Equipment Design , Filtration/methods , Humans , Humidity , Materials Testing , Root Canal Preparation/instrumentation , Surface Properties , Temperature , Time Factors , Tooth Apex/anatomy & histologyABSTRACT
The aim of this study was to compare the cyclic fatigue resistance of rotary NiTi files, produced with four different manufacturing methods on specially designed dynamic models that simulated clinical conditions. In this study, 120 files, consisting of 30 files for Typhoon, ProTaper Next, RaCe, and Twisted Files nickel titanium rotary systems were used. The 30 files of each group were divided into three subgroups to be used in artificial canals with a 60° angle of curvature and radii of curvature of 2, 5, and 8 mm (n = 10). All files were rotated in the artificial canals until fracture occurred and the number of cycles to fracture was calculated. The data were analyzed using one- and two-way analyses of variance and Tamhane multiple comparison tests. In all three groups, Typhoon instruments had the highest number of cycles to failure than the RaCe, ProTaper Next, and Twisted Files instruments, and the difference statistically significant (p < .05). There were no significant differences between the RaCe, ProTaper Next, and Twisted Files groups (p > .05). The CM wire Typhoon system was significantly more resistant to cyclic fatigue compared to the other file systems in all three artificial canals. When the fracture resistance of an instrument in three different artificial canals was compared, the mean NCFs decreased as the radius of the curvature of the canal decreased from 8 to 2 mm. Manufacturing method is one of the most important factors on cyclic fatigue resistance, also the radius of curvature effects the cyclic fatigue.
ABSTRACT
OBJECTIVES: The aim of this study was to investigate the effect of glide path preparation with PathFile and ProGlider nickel-titanium (NiTi) files on the cyclic fatigue resistance of WaveOne NiTi files. MATERIALS AND METHODS: Forty-four WaveOne Primary files were used and divided into four groups (n = 11). In the first group (0 WaveOne), the WaveOne Primary files served as a control group and were not used on acrylic blocks. In the 1 WaveOne Group, acrylic blocks were prepared using only WaveOne Primary files, and in the PF+WaveOne group and PG+WaveOne groups, acrylic blocks were first prepared with PathFile or ProGlider NiTi files, respectively, followed by the use of WaveOne Primary files. All the WaveOne Primary files were then subjected to cyclic fatigue testing. The number of cycles to failure was calculated and the data were statistically analyzed using one-way analysis of variance (ANOVA) and the Tukey honest significant difference multiple-comparison test at a 5% significance level. RESULTS: The highest number of cycles to failure was found in the control group, and the lowest numbers were found in the 1 WaveOne group and the PF+WaveOne group. Significant differences were found among the 1 WaveOne, PF+WaveOne, and control groups (p < 0.05). No statistically significant differences were found between the PG+WaveOne group and the other three groups (p > 0.05). CONCLUSION: Glide path preparation with NiTi rotary files did not affect the cyclic fatigue resistance of WaveOne Primary files used on acrylic blocks.
ABSTRACT
INTRODUCTION: The present study aimed to compare the torsional resistance of ProGlider (Dentsply Sirona, Ballaigues, Switzerland), Hyflex EDM (Coltene-Whaledent, Altstätten, Switzerland), and One G (Micro-Mega, Besancon, France) glide path instruments. METHODS: Fifteen ProGlider (16.02â¼08), 15 Hyflex EDM (10.05), and 15 One G (14.03) instruments were collected and tested for torsional strength using a custom-designed testing device. Data were analyzed using 1-way analysis of variance and Tukey post hoc tests with 5% significance level. The tested specimens were examined under a scanning electron microscope. RESULTS: There was no significant difference between Hyflex EDM and ProGlider regarding their torsional resistance values (P > .05). One G showed the lowest torsional resistance (P < .05). Hyflex EDM exhibited the highest angle of rotation values among the instruments (P < .05). CONCLUSIONS: Hyflex EDM and ProGlider instruments had significantly higher torsional fatigue resistance than One G instruments, whereas Hyflex EDM showed the highest angle of rotation values. The differences in the torsional resistances might be associated with their different design features and manufacturing processes.
Subject(s)
Dental Instruments , Root Canal Preparation , Equipment Design , Equipment Failure , Materials Testing , Rotation , Torsion, MechanicalABSTRACT
INTRODUCTION: The aim of this study was to compare the cyclic fatigue resistance of the ProTaper Gold (PTG; Dentsply Maillefer, Ballaigues, Switzerland), K3XF (SybronEndo, Orange, CA), and XP-endo Shaper (FKG Dentaire, La Chaux-de-Fond, Switzerland) nickel-titanium rotary instruments at intracanal temperatures. METHODS: Eighteen XP-endo Shaper (30.01), 18 K3XF (30.04), and 18 PTG F3 (30.09v) instruments were used to test the cyclic fatigue resistance at an intracanal temperature of 35° ± 2°C. The instruments were tested in a metal block that simulated a canal curvature angle of 60° and a curvature or radius of 5 mm. All instruments were operated until fracture occurred, and then the number of cycles to failure was calculated. The lengths of fractured fragments were measured with a digital caliper. The data were analyzed statistically using 1-way analysis of variance and the Tukey post hoc test with significance set at P < .05. RESULTS: The XP-endo Shaper instruments showed a significantly higher number of cycles to fracture than the K3XF and PTG instruments (P < .05). There was no difference between the PTG and K3XF instruments (P > .05). CONCLUSIONS: The XP-endo Shaper instruments exhibited greater cyclic fatigue resistance compared with the other instruments at the intracanal temperature.
Subject(s)
Root Canal Preparation/instrumentation , Alloys , Dental Alloys , Equipment Failure Analysis , HumansABSTRACT
The aim of this in vivo study was to evaluate the performance of ProPex apex locator after extirpation and in presence of different irrigation solutions: 2.5% NaOCl, 0.9% NaCl, and 0.2% chlorhexidine gluconate solutions. Twenty-seven single-rooted human teeth scheduled for extraction with mature apices were selected for this study. Measurements were performed by using ProPex after extirpation and in presence of the irrigation solutions. After extraction of the teeth, a stereomicroscope was used to confirm visually the relationship of the tip of the endodontic file to the apical foramen, and actual lengths (ALs) were determined by reducing 0.5 mm from these lengths. The data were statistically analyzed with cluster analysis. The results of this study showed that measurements after extirpation had the smallest distance to the ALs. Among the irrigation solution groups, chlorhexidine gluconate group had the smallest distance to the ALs, whereas saline group had the greatest. Most accurate measurements were obtained after extirpation.
Subject(s)
Dental Instruments , Dental Pulp Cavity/anatomy & histology , Root Canal Preparation/instrumentation , Tooth Apex/anatomy & histology , Adult , Cluster Analysis , Electronics, Medical , Humans , Middle Aged , Odontometry/instrumentation , Root Canal IrrigantsABSTRACT
The purpose of this study was to evaluate the topography of new and used ProTaper rotary nickel-titanium (NiTi) instruments by using atomic force microscope. Four new and four used size S1, S2, F1, and F2 instruments were selected for this study. New and used instruments were analyzed on 11 points along a 3-mm section at the tip of the instrument. Quantitative measurements according to the topographic deviations (root mean square) were recorded. Data were analyzed by paired samples t test. Mean root mean square values for used ProTaper instruments were higher than the new ones, and the difference between them was statistically significant. The results of this study showed that used ProTaper instruments demonstrated more surface deformation and wear.
Subject(s)
Dental Instruments , Root Canal Preparation/instrumentation , Analysis of Variance , Dental Alloys , Equipment Reuse , Microscopy, Atomic Force , Nickel , Surface Properties , TitaniumABSTRACT
The aim of this study was to compare the apical sealing ability of three different obturation techniques using an electrochemical evaluation and evaluating dye penetration. One hundred and thirty-two maxillary anterior teeth were randomly divided into six groups. There were 20 teeth in each group. The teeth were obturated as follows: Groups 1 and 4 with Thermafil, Groups 2 and 5 with System B, and Groups 3 and 6 with cold lateral condensation (CLC). The apical leakage in these groups was evaluated using an electrochemical method for Groups 1, 2, 3 and a dye penetration method for Groups 4, 5 and 6. In both methods, the lowest mean leakage values were observed for Thermafil and the highest were observed for the CLC groups. The difference between Thermafil and CLC was statistically significant (P < 0.05). In both groups, System B fillings showed moderate leakage and the difference was not significant with Thermafil and CLC groups.
Subject(s)
Dental Leakage/prevention & control , Root Canal Obturation/methods , Analysis of Variance , Bismuth , Coloring Agents , Dental Leakage/diagnosis , Drug Combinations , Electric Conductivity , Gutta-Percha , Humans , Polyvinyls , Root Canal Filling Materials , Zinc OxideABSTRACT
INTRODUCTION: The purpose of this study was to compare the cyclic fatigue resistance of used and new ProGlider (Dentsply Maillefer, Ballaigues, Switzerland) and PathFile (Dentsply Maillefer) rotary glide path files. METHODS: Forty ProGlider and 40 PathFile #2 instruments were used in the present study. In group 1, 20 PathFile #2 files and, in group 2, 20 ProGlider files were used to prepare a total of 40 J-shaped transparent acrylic blocks. In group 3 (control group), 20 new PathFile files and, in group 4 (control group), 20 new ProGlider files were included. Cyclic fatigue testing of instruments was performed in a stainless steel artificial canal with a 5-mm radius of curvature and a 60° angle of curvature. All 80 instruments were rotated until fracture, and the number of cycles to failure (NCF) was recorded. Data were analyzed using 1-way analysis of variance to determine any statistical difference; the significance was determined at the 95% confidence level. RESULTS: The used glide path files' NCF was lower than the new ones; however, this difference was not statistically significant (P > .05). The cyclic fatigue resistance of the used and new PathFile #2 files was statistically significantly higher than that of the ProGlider files (P < .05). CONCLUSIONS: Within the limitations of the present study, the used glide path files' NCF was lower than the new ones; however, this difference was not statistically significant.
Subject(s)
Dental Instruments , Materials Testing , Root Canal Preparation/instrumentation , Equipment Design , Equipment Failure AnalysisABSTRACT
INTRODUCTION: The aim of the present study was to compare the cyclic fatigue resistance of Reciproc Blue R25 (VDW, Munich, Germany) with Reciproc R25 (VDW) and WaveOne Gold Primary (Denstply Maillefer, Ballaigues, Switzerland). METHODS: Fifteen Reciproc Blue R25, 15 Reciproc R25, and 15 WaveOne Gold Primary instruments were collected and tested in a dynamic cyclic fatigue test device, which has an artificial canal with a 60° angle of curvature and a 5-mm radius of curvature. All instruments were operated until fracture occurred, and time to fracture (TF) and the lengths of the fractured fragments were recorded. The mean and standard deviations of TF and fragment length were calculated for each reciprocating system. TF data were subjected to Kruskal-Wallis 1-way analysis of variance and the Dunn test, whereas fractured fragment length data were subjected to 1-way analysis of variance (P < .05). RESULTS: Reciproc Blue R25 exhibited the highest cyclic fatigue resistance (P < .05). The cyclic fatigue resistance values of WaveOne Gold Primary were significantly higher than those of Reciproc R25 (P < .05). There was no significant difference in the mean length of the fractured fragments among the instruments (P > .05). CONCLUSIONS: Reciproc Blue R25 instruments had significantly higher cyclic fatigue resistance than WaveOne Gold and Reciproc R25 instruments.
Subject(s)
Dental Instruments , Equipment Failure Analysis/methods , Root Canal Preparation/instrumentation , Dental Stress Analysis , Equipment Design , Materials Testing , Nickel , Stress, Mechanical , Titanium , Torsion, MechanicalABSTRACT
OBJECTIVES: To determine the actual revolutions per minute (rpm) values and compare the cyclic fatigue life of Reciproc (RPC, VDW GmbH), WaveOne (WO, Dentsply Maillefer), and TF Adaptive (TFA, Axis/SybronEndo) nickel-titanium (NiTi) file systems using high-speed camera. MATERIALS AND METHODS: Twenty RPC R25 (25/0.08), 20 WO Primary (25/0.08), and 20 TFA ML 1 (25/0.08) files were employed in the present study. The cyclic fatigue tests were performed using a dynamic cyclic fatigue testing device, which has an artificial stainless steel canal with a 60° angle of curvature and a 5-mm radius of curvature. The files were divided into 3 groups (group 1, RPC R25 [RPC]; group 2, WO Primary [WO]; group 3, TF Adaptive ML 1 [TFA]). All the instruments were rotated until fracture during the cyclic fatigue test and slow-motion videos were captured using high-speed camera. The number of cycles to failure (NCF) was calculated. The data were analyzed statistically using one-way analysis of variance (ANOVA, p < 0.05). RESULTS: The slow-motion videos were indicated that rpm values of the RPC, WO, and TFA groups were 180, 210, and 425, respectively. RPC (3,464.45 ± 487.58) and WO (3,257.63 ± 556.39) groups had significantly longer cyclic fatigue life compared with TFA (1,634.46 ± 300.03) group (p < 0.05). There was no significant difference in the mean length of the fractured fragments. CONCLUSIONS: Within the limitation of the present study, RPC and WO NiTi files showed significantly longer cyclic fatigue life than TFA NiTi file.
ABSTRACT
INTRODUCTION: The aim of this study was to compare the cyclic fatigue resistances of nickel-titanium rotary glide path files, which are manufactured as single-file systems, under dynamic model. METHODS: Twenty ProGlider (16.02) and 20 One G (14.03) nickel-titanium glide path files were included in this study. Cyclic fatigue tests were performed with specifically manufactured dynamic cyclic testing device. The device has an artificially prepared canal with 60° curvature angle and 5-mm curvature radius. The canal inner diameter is 1.5 mm, and its curvature center is located at the coronal 5 mm from the apical. The files were randomly divided into 2 groups (n = 20): group 1, ProGlider; group 2, One G. Time to fracture was recorded, and the number of cycles to failure for each instrument was obtained. Statistical analyses were performed by using independent samples t test. The statistically significant level was set at P < .05. RESULTS: The cyclic fatigue resistance of ProGlider files was found to be statistically significantly higher than that of the One G files (P < .05). CONCLUSIONS: Within the limitations of the present study, it was concluded that the cyclic fatigue resistance of ProGlider, which is manufactured as single-file glide path system, is higher than that of the One G file.
Subject(s)
Dental Instruments , Dental Stress Analysis/instrumentation , Equipment Failure , Root Canal Preparation/instrumentation , Dental Alloys , Equipment Design , Materials Testing , Nickel , Stress, Mechanical , Titanium , Torsion, MechanicalABSTRACT
INTRODUCTION: A number of rotary nickel-titanium (NiTi) systems have been developed to provide better, faster, and easier cleaning and shaping of the root canal system, and recently, rotary NiTi systems designed for root canal retreatment have been introduced. Because the main problem with the rotary NiTi files is fracture, the aim of this study was to compare the cyclic fatigue resistance of 3 different rotary NiTi systems designed for root canal retreatment. METHODS: Total of 60 instruments of 3 different rotary NiTi systems designed for root canal retreatment were used in this study. Twenty R-Endo R3, 20 ProTaper D3, and 20 Mtwo R (Retreatment) 25.05 instruments were tested. Cyclic fatigue testing of instruments was performed by using a device that allowed the instruments to rotate freely inside an artificial canal. Each instrument was rotated until fracture occurred, and the number of cycles to fracture for each instrument was calculated. Representative samples were also evaluated under a scanning electron microscope to confirm the fracture was flexural. Data were analyzed by using 1-way analysis of variance test. RESULTS: R-Endo R3 instruments showed better cyclic fatigue resistance than ProTaper D3 and Mtwo R 25.05 instruments, and the difference was statistically significant (P < .05). There was no significant difference between ProTaper D3 and Mtwo R 25.05 groups. CONCLUSIONS: The R-Endo R3 instruments were more resistant to fatigue failure than ProTaper D3 and Mtwo R 25.05.