Surface profile of different heat-treated nickel-titanium files before and after root canal preparation

Abstract The aim of this study was to evaluate surface wear, presence of microcracks and surface irregularities of WaveOne (WO) and WaveOne Gold (WOG) instruments before and after multiple uses. Eight Primary instruments of the WO and WOG systems were evaluated, each one was used to prepare six mesial canals of extracted human mandibular molars. The surface of the instruments was evaluated before use (T0), after instrumentation of three (T1) and six (T2) root canals. Surface wear was analyzed using a three-dimensional optical profiler and the presence of microcracks and surface irregularities were evaluated using a tabletop scanning electron microscopy. The Friedman test was used to assess surface wear and Kruskal-Wallis test to evaluate the presence of microcracks and surface irregularities, with a 5% significance level. There was a significant increase in wear in both groups at T2, compared to T0 (p=0.0003). The surface wear after instrumentation of six canals (T2-T0) was statistically greater in the WOG group, than in the WO group (p=0.02), where the presence of microcracks was significantly greater and increased after multiple uses (p<0.05). The presence of surface irregularities in the cutting blade before and after use was statistically greater in the WOG group than WO group (p<0.05). Wear of the cutting blade, microcracks and surface irregularities were observed on the surface topography of all the instruments after multiple uses. These surface changes may affect the cutting efficiency of WOG files and increase the risk of fracture of WO files.

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Shaping and Centering Ability, Cyclic Fatigue Resistance and Fractographic Analysis of Three Thermally Treated NiTi Endodontic Instrument Systems

Materials ◽

10.3390/ma13245823 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5823

Author(s):

Saulius Drukteinis ◽

Vytaute Peciuliene ◽

Ruta Bendinskaite ◽

Vilma Brukiene ◽

Rasmute Maneliene ◽

...

Keyword(s):

Fatigue Resistance ◽

Cyclic Fatigue ◽

Fractographic Analysis ◽

Significance Level ◽

Root Canals ◽

Topographic Features ◽

New Instrument ◽

Before And After ◽

Number Of Cycles ◽

Thermally Treated

The better understanding of the clinically important behavioral features of new instrument systems has an important significance for the clinical endodontics. This study aimed to investigate the shaping and centering ability as well as cyclic fatigue resistance of HyFlex CM (CM), HyFlex EDM (EDM) and EdgeFile (EF) thermally treated nickel–titanium (NiTi) endodontic instrument systems. Sixty curved root canals of the mesial roots of mandibular molars were randomly assigned into three groups (n = 20) and shaped using CM, EDM and EF files up to the size 40 and taper 04 of the instruments. µCT scanning of the specimens before and after preparation was performed and the morphometric 2D and 3D parameters were evaluated in the apical, middle and coronal thirds of root canals. In each group, 40.04 instruments (n = 20) were subjected to the cyclic fatigue resistance test in artificial root canals at 37 °C temperature until fractures occurred, and the number of cycles to failure (NCF) was calculated. The fractographic analysis was performed using a scanning electron microscope, evaluating topographic features and surface profiles of the separated instruments. The one-way analysis of variance with post hoc Tuckey’s test was used for statistical analysis of the data; the significance level was set at 5%. All systems prepared the comparable percentage of root canal surface with the similar magnitude of canal transportation in all root thirds (p > 0.05), but demonstrated significantly different resistance to cyclic fatigue (p < 0.05). The most resistant to fracture was EF, followed by EDM and CM. The length of the fractured fragments was not significantly different between the groups, and fractographic analysis by SEM detected the typical topographic features of separated thermally treated NiTi instrument surfaces.

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Safety and Effectiveness of Additional Apical Preparation using a Rotary Heat-treated Nickel–Titanium file with Larger Diameter and Minimum Taper in Retreatment of Curved Root Canals

European Journal of Dentistry ◽

10.1055/s-0041-1723065 ◽

2021 ◽

Author(s):

Jader Camilo Pinto ◽

Fernanda Ferrari Esteves Torres ◽

Airton Oliveira Santos-Junior ◽

Marco Antonio Hungaro Duarte ◽

Juliane Maria Guerreiro-Tanomaru ◽

...

Keyword(s):

Fatigue Resistance ◽

Continuous Wave ◽

Cyclic Fatigue ◽

Nickel Titanium ◽

Filling Material ◽

Root Canals ◽

Filling Materials ◽

Heat Treated ◽

Before And After ◽

Curved Root Canals

Abstract Objective The aim of this study was to investigate the effect of additional apical preparation using the ProDesign Logic (PDL) 50/.01 rotary heat-treated nickel–titanium (NiTi) file with a larger diameter and minimal taper for retreatment of curved root canals. Materials and Methods Mesial curved root canals of 12 mandibular molars were prepared using PDL 25/.06 and filled using the continuous wave of condensation technique and AH Plus sealer. After retreatment using ProDesign S (PDS) 25/.08, PDL 25/.06 and PDL 35/05, a complementary procedure was performed with PDL 50/.01. Microcomputed tomography (micro-CT) scanning was performed before and after retreatment procedures. The cyclic fatigue resistance of unused PDS 25/.08, PDL 25/.06, PDL 35/.05 and PDL 50/.01 instruments (n = 12) was evaluated in a stainless-steel device. Statistical Analysis Data on the volumes of the root canals and the remaining filling materials were submitted to the paired t-test. Cyclic fatigue resistance data was submitted to one-way ANOVA and Tukey’s tests (α = 0.05). Results Use of PDL 50/.01 decreased the remaining filling materials in the apical third (p < 0.05). The root canal volume was similar in the cervical and middle thirds before and after preparation using PDL 50/.01 (p > 0.05). PDL 50/.01 presented the highest cyclic fatigue resistance (p < 0.05). Conclusions Use of the PDL 50/.01 instrument as an additional apical preparation for retreatment of curved root canals improved filling material removal in the apical third, while maintaining the dentin in the cervical and middle thirds. In addition, PDL 50/.01 presented high-flexural resistance.

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Shaping Ability of XP Endo Shaper File in Curved Root Canal Models

International Journal of Dentistry ◽

10.1155/2020/4687045 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Abdulmohsen Alfadley ◽

Abdalrhman Alrajhi ◽

Hamad Alissa ◽

Faisal Alzeghaibi ◽

Lubna Hamadah ◽

...

Keyword(s):

Body Temperature ◽

File Systems ◽

Lower Number ◽

Significance Level ◽

Root Canals ◽

Shaping Time ◽

Significant Difference ◽

Before And After ◽

Canal Shaping ◽

Shaping Ability

The aim of this study was to assess the shaping ability of the XP Shaper (XPS) file in severely curved canal models under simulated body temperature and compare it with that of the WaveOne Gold (WOG) file. Ninety-six simulated root canals were equally distributed into XPS and WOG systems to be shaped by eight files each. Files were assessed under a stereomicroscope prior to canal shaping to detect deformation if any. The canals were shaped at 35 ± 1°C using the X-Smart Plus motor. Images of the canals were obtained before and after instrumentation using a stereomicroscope to measure the amount of removed resin from both the inner and outer curvature sides at apex (0 mm) and 3 mm and 6 mm from the apex. The shaping time was calculated. The data were statistically analyzed by the independent t-test at 5% significance level. The XPS and WOG systems shaped the canals in 37.0 ± 9.5 and 62.6 ± 11.3 seconds (P<0.05), respectively. At the apex level, the amount of resin removal in both sides did not show a significant difference between the tested groups (P>0.05). At 3 mm and 6 mm levels, the WOG removed more resin than XPS at both sides (P<0.05). In XPS, deformation was observed in four files: one file after the first use, one file after the fourth use, and two files after the sixth use. In WOG, two files were deformed: one file after the fifth use and one file after the sixth use. One XPS file was fractured after the sixth use. In short, XPS and WOG files can be used in shaping severely curved canals as they showed the ability to maintain the original shape with minimal transportation. Both file systems showed signs of deformation after use with a lower number of deformed files observed in WOG throughout the experiment.

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A modified approach based on bearing area curve for surface wear characterization

Industrial Lubrication and Tribology ◽

10.1108/ilt-06-2019-0233 ◽

2020 ◽

Vol 72 (3) ◽

pp. 273-278

Author(s):

Yun Wang ◽

Junhong Mao ◽

Suwen Lu ◽

Zhenying Xu ◽

Hong Liu ◽

...

Keyword(s):

Three Dimensional ◽

Surface Profile ◽

Surface Wear ◽

H13 Steel ◽

Wear Area ◽

Content Type ◽

Profile Method ◽

Wear Analysis ◽

Curve Method ◽

Worn Surface

Purpose Wear greatly influences the machine lifetime, performance and reliability and its quantification is very important. This paper aims to propose a modified bearing area curve method by combining the theory of the bearing area curve, and the relocation technique to calculate wear accurately and efficiently. Design/methodology/approach H13 steel was chosen as the material of wear pair, and the wear experiments were carried out at 50 N, 60 r/min for 20 min. The surface was measured before and after wear experiments. The relocation was made by comparing the mean lines (planes) of the unworn and worn surface profiles. The calculated results using the proposed method were compared with that of the surface profile method for a two-dimensional surface to validate its accuracy. The method was then applied for a three-dimensional (3D) wear analysis. Findings The worn surface shows clearly displacement compared to the unworn surface and implies the importance of including relocation in the bearing area curve method. The results from the proposed method are 98 per cent close to that from the surface profile method, indicating that the method is accurate for wear evaluation. Originality/value As no feature point or relocation mark is needed to calculate the relocation value using the proposed method, the method can be applied to mild to severe wear. Also, as the deviation of different scans does not affect the relocation calculation, and no matching and stitching is required, this method can be easily applied to a wide wear area and 3D surface wear analysis.

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The Effect of Ultrasonic Agitation on the Porosity Distribution in Apically Perforated Root Canals Filled with Different Bioceramic Materials and Techniques: A Micro-CT Assessment

Journal of Clinical Medicine ◽

10.3390/jcm10214977 ◽

2021 ◽

Vol 10 (21) ◽

pp. 4977

Author(s):

Saulius Drukteinis ◽

Goda Bilvinaite ◽

Hagay Shemesh ◽

Paulius Tusas ◽

Vytaute Peciuliene

Keyword(s):

Root Canal ◽

Micro Computed Tomography ◽

Root Canal Filling ◽

Porosity Distribution ◽

Significance Level ◽

Ultrasonic Agitation ◽

Root Canals ◽

Gutta Percha ◽

Before And After ◽

Rotary Instrument

The present study evaluated the effect of ultrasonic agitation on the porosity distribution of BioRoot RCS/single gutta-percha cone (BR/SC) and MTA Flow (MF) root canals fillings used as apical plugs in moderately curved and apically perforated roots. Eighty mesial root canals of mandibular first molars were enlarged up to ProTaper NEXT X5 rotary instrument 2 mm beyond the apical foramen, simulating apical perforations. Specimens were randomly divided into four experimental groups (20 canals per group) according to the material and technique used for root canal obturation: BR/SC, BR/SC with ultrasonic agitation (BR/SC-UA), MF and MF with ultrasonic agitation (MF-UA). The ultrasonic tip was passively inserted into the root canal after the injection of flowable cement and activated for 10 s. The specimens were scanned before and after obturation with a high-resolution micro-computed tomography scanner, and the porosity of the apical plugs was assessed. The differences between groups were analyzed using the Kruskal-Wallis and Mann-Whitney tests, with the significance level set at 5%. None of the obturation materials and techniques used in this study was able to provide a pore-free root canal filling in the apical 5 mm. Considerably higher percentages of open and closed pores were observed in the MF and MF-UA groups, with the highest porosity being in the MF-UA group (p < 0.05). No significant differences were observed between the BR/SC and BR/SC-UA groups, where the quantity of open and closed pores remained similar (p > 0.05).

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Dentinal Microcrack Formation after Root Canal Instrumentation by XP-Endo Shaper and ProTaper Universal: A Microcomputed Tomography Evaluation

International Journal of Dentistry ◽

10.1155/2020/4030194 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Sarah M. Alkahtany ◽

Ebtissam M. Al-Madi

Keyword(s):

The Body ◽

Micro Ct ◽

Cross Sectional ◽

Significance Level ◽

Root Canals ◽

Type Iv ◽

Significant Difference ◽

Before And After ◽

Microcrack Formation ◽

Group 2

Aim. To evaluate dentinal microcrack formation on root canals instrumented, continuously in the body temperature, with XP-endo shaper (XPES) and ProTaper Universal (PTU), by means of microcomputed tomographic (micro-CT) analysis. Methodology. Nineteen mesial roots with two separate canals (Vertucci Type IV) of extracted mandibular molars were used in this study. The root canals (N = 38) were divided into 2 groups. Group 1 (n = 19): all MB canals were instrumented with XPES. Group 2 (n = 19): all ML canals were instrumented with PTU. All roots were scanned with micro-CT before and after instrumentation. Two precalibrated examiners evaluated the cross-sectional images of each sample with DataViewer program. The dentinal microcracks (complete and incomplete) were counted in each third of the root for the preinstrumentation and the postinstrumentation images. Wilcoxin signed-rank and Mann–Whitney U tests were used for statistical analysis at a significance level of P<0.05. Results. The number of microcracks increased significantly (P<0.05) after instrumentation with XPES in the middle and cervical thirds. The number of microcracks increased significantly (P<0.05) after instrumentation with PTU in the cervical third only. There was no significant difference between the groups in the cervical and apical thirds. In the middle third, the XPES induced more incomplete microcracks than PTU (P<0.05). Conclusion. Within the limitations of this study, there was no significant difference in the dentinal microcrack formation between XPES and PTU in the apical and cervical thirds of the root. However, XPES instrumentation induced more incomplete microcracks than PTU in the middle third of human roots.

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The Implications of Energetic and Kinetic Surface Instability for a Stress Measurement Technique

MRS Proceedings ◽

10.1557/proc-594-495 ◽

1999 ◽

Vol 594 ◽

Author(s):

H. H. Yu ◽

Z. Suo

Keyword(s):

Activation Energy ◽

Stress State ◽

Measurement Technique ◽

Elastic Energy ◽

Stress Measurement ◽

Three Dimensional ◽

Surface Profile ◽

Surface Instability ◽

Before And After ◽

Stress Dependent

AbstractIt has been understood for some time that elastic energy can cause surface roughening during a solid surface motion. This instability has recently led to a novel experimental technique to determine stress state on the surface of a solid by measuring the surface profile before and after etching [1]. Along a separate line of investigation, Aziz and co-workers has recently described a different kind of instability, also driven by stress [2]. Their experiments showed that the activation energy of the surface mobility depends linearly on the stress state, and this dependence can cause surface instability. The two kinds of instabilities have very different characteristics. In this paper, we describe a linear stability analysis of a three dimensional interface evolving under stress. The interface can be destabilized either by stress-dependent activation energy or by elastic energy. The implications for the stress measurement technique are discussed. It is suggested that the same experimental procedure be used to measure surface energy and activation strains.

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Effect of post–orthognathic surgery condylar axis changes on condylar morphology as determined by 3-dimensional surface reconstruction

The Angle Orthodontist ◽

10.2319/052113-387.1 ◽

2013 ◽

Vol 84 (2) ◽

pp. 316-321 ◽

Cited By ~ 18

Author(s):

Soo-Bum An ◽

Soo-Byung Park ◽

Yong-Il Kim ◽

Woo-Sung Son

Keyword(s):

Orthognathic Surgery ◽

Pearson Correlation ◽

Three Dimensional ◽

Class Iii ◽

Absolute Deviation ◽

Skeletal Class ◽

Before And After ◽

Group 2 ◽

Jaw Surgery ◽

Surface Changes

ABSTRACT Objective: To evaluate the effect of postoperative condylar axis changes on mandibular condylar remodeling by comparing the condylar head in three-dimensional (3D) surface reconstructions before and after surgery in skeletal Class III deformities (one-jaw [mandibular setback] or two-jaw surgery), and also to determine the relationship between condylar inward rotation and condylar surface remodeling after orthognathic surgery. Materials and Methods: A retrospective analysis was conducted of 30 patients with skeletal Class III deformities who had received orthognathic surgery. Group 1 underwent one-jaw surgery (10 men, five women, age 22.4 ± 3.3 years), and group 2 underwent two-jaw surgery (10 men, five women, age 22.3 ± 2.2 years). Sixty condyles were reconstructed and superimposed pre- and postoperatively to compare the changes of condylar surfaces. The relation between the condylar axis change and the surface change using the Pearson correlation were investigated from the 3D image software. Results: Condylar surface changes before and after the surgery were significant. The postoperative inward rotation of the condyles was correlated with the average absolute deviation of the condyles, regardless of the surgery type (one- or 2-jaw surgery; r = .70, P < .05). Conclusion: After orthognathic surgery, condylar surface changes occurred, and condylar inward rotation was closely related to changes of condylar surface.

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Efficiency of different instruments used for composite filling polishing.

Acta Stomatologica Marisiensis Journal ◽

10.2478/asmj-2021-0005 ◽

2021 ◽

Vol 4 (1) ◽

pp. 31-37

Author(s):

Andrea-Csinszka Kovacs-Ivacson ◽

Alexandra Mihaela Stoica ◽

Mónika Kovacs ◽

Mihai Pop

Keyword(s):

Surface Roughness ◽

Control Group ◽

Mean Values ◽

Significance Level ◽

Caries Treatment ◽

Before And After ◽

Long Time ◽

Surface Irregularities ◽

Surface Staining

Abstract Introduction: Improper finishing and polishing of fillings leads to surface roughness of the restoration which leads to excessive plaque accumulation, gingival irritation, increased surface staining and poor aesthetics of restored teeth. Therefore, it is essential to use polishing instruments and pastes as a final step of simple caries treatment in order to achieve optimal long-time results. The aim of this study is to evaluate the efficiency of 4 different finishing and polishing instruments used for surface smoothening of aesthetic restorative materials in vitro. Materials and methods: 40 composite (Reality X) samples were prepared in vitro. Their surface irregularities were measured along 3 diagonals before and after polishing. Sof-Lex discs (3M Espe), rubber cones (Kenda), Arkansas stone (Fino) and polishing paste and a professional toothbrush (Kerr) were used for polishing. Each sample was polished under 5N pressure for 30 seconds at 3000 rpm. The surface roughness was than measured using a profilometer. Statistic analysis was performed using ANOVA and unpaired T-tests, the significance level was set at a value of p<0.05. Results: Based on the mean values, the smallest roughness was found in the control group- 0.11, while the highest in the rubber polishers and Arkansas stone group- 0.47 and 0.48. The values for the Sof-Lex disc group and the polishing paste-toothbrush group were 0.40 and 0.39. Statistical analysis showed no significant differences between the four groups. Conclusion: It is mandatory to use polishing tools in order to obtain a smooth surface of the restoration and avoid the unwanted long-term complications. Polishing using brush and abrasive paste produced the smoothest surface of the composite.

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The impact of 60-minute swimming training on the quality of body posture and the level of balance of young adults

Health Promotion & Physical Activity ◽

10.5604/01.3001.0012.8374 ◽

2019 ◽

Vol 4 (3) ◽

pp. 1-6

Author(s):

Dżesika Aksamit ◽

Tomasz Sidor ◽

Adrian Gądek ◽

Agnieszka Jankowicz-Szymańska

Keyword(s):

Thoracic Kyphosis ◽

Three Dimensional ◽

Frontal Plane ◽

The Body ◽

Body Posture ◽

Swimming Training ◽

Significance Level ◽

Before And After ◽

The Impact

Introduction: Postural abnormalities are common in every age group. They often involve discomfort or pain. Unfortunately, specialist posture correcting body postures are almost exclusively for pre-school and school children. There is a widespread belief in the beneficial effects of swimming on the body posture. Some even think that swimming can replace corrective exercises. The aim of the study was to evaluate the changes in the quality of body posture and body balance under the influence of 60-minute intensive swimming training in people aged 20-22 years, whose level of swimming skills was determined as average. Material and methods: The study was conducted on a group of 9 people, students of the State Higher Vocational School in Tarnów. Ultrasonic device Zebris Pointer was used for three-dimensional assessment of body posture. The position of the shoulder and iliac girdle, the shape of the spine, the inclination of the sacrum bone and the inclination of the body in the sagittal and frontal plane were analyzed. The test was repeated before and after the one-hour lecture and before and after one-hour, intensive classes at the swimming pool. The results were developed in the Statistika v10 program. Descriptive statistics, non-parametric Friedman test and Kruskal posthoc test were used. The significance level α = 0.05 was assumed. Results: There was a statistically significant increase in pelvic rotation under the influence of swimming training. There was also a slight deterioration of the spine position in the frontal plane. Exercises improving swimming in the classic style did not affect the depth of thoracic kyphosis and lumbar lordosis. After 60 minutes spent in a relaxed sitting position, deepening thoracic kyphosis was observed. However, this change was not statistically significant. Conclusions: It is not recommended to treat swimming as a substitute for corrective gymnastics. Intensive swimming training can exacerbate existing body posture errors in people who are just improving their swimming technique.

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