CM Files Research Articles

Comparison of the Amount of Debris Extruded From the Apex During Retreatment Procedures Using Several File Systems and to Gauge the Effect of Same and Different Taper on the Debris Extrusion: An In Vitro Study.

To determine the amount of apical extrusion between various file systems during the retreatment procedure and to determine the effect of taper on the same. Seventy mandibular extracted premolars were taken, and preparation was performed using a Woodpecker file (Woodpecker Medical Instrument Co., Ltd., Guilin, China) (25/0.06). The gutta-percha (GP) was removed from each specimen with H file (#40/0.02) to simulate retreatment in seven groups (n = 10) using ProTaper Next (PTN;Dentsply, Maillefer, Ballaigues, Switzerland) (PTN) (30/0.07), Reciproc (25/0.08), Hyflex CM (30/0.06), Mtwo (30/0.05), Neoendo flex (30/0.04), Neoendo hybrid (30/0.04), and Flexicon file (30/0.06). The specimens were held with the help of a rubber stopper and put in the Eppendorf tube of volume 4 mL (pre-weighed before retreatment). The debris that was on the root surface of the specimen was washed with distilled water with 1 mL volume, kept in the oven, and then again weighed after 7 days. Apical extrusion was found in the following order: HYFLEX CM (LEAST) < FLEXICON < PROTAPER NEXT < RECIPROC < NEOENDO FLEX < NEOENDO HYBRID < MTWO (HIGHEST). W Hyflex CM and Flexicon files showed lesser extrusion of debris than others.

National Estimates of Short- and Longer-Term Hospital Readmissions After Major Surgery Among Community-Living Older Adults

Nationally representative estimates of hospital readmissions within 30 and 180 days after major surgery, including both fee-for-service and Medicare Advantage beneficiaries, are lacking. To provide population-based estimates of hospital readmission within 30 and 180 days after major surgery in community-living older US residents and examine whether these estimates differ according to key demographic, surgical, and geriatric characteristics. A prospective longitudinal cohort study of National Health and Aging Trends Study data (calendar years 2011-2018), linked to records from the Centers for Medicare & Medicaid Services (CMS). Data analysis was conducted from April to August 2023. Participants included community-living US residents of the contiguous US aged 65 years or older who had at least 1 major surgery from 2011 to 2018. Data analysis was conducted from April 10 to August 28, 2023. Major operations and hospital readmissions within 30 and 180 days were identified through data linkages with CMS files that included both fee-for-service and Medicare Advantage beneficiaries. Data on frailty and dementia were obtained from the annual National Health and Aging Trends Study assessments. A total of 1780 major operations (representing 9 556 171 survey-weighted operations nationally) were identified from 1477 community-living participants; mean (SD) age was 79.5 (7.0) years, with 56% being female. The weighted rates of hospital readmission were 11.6% (95% CI, 9.8%-13.6%) for 30 days and 27.6% (95% CI, 24.7%-30.7%) for 180 days. The highest readmission rates within 180 days were observed among participants aged 90 years or older (36.8%; 95% CI, 28.3%-46.3%), those undergoing vascular surgery (45.8%; 95% CI, 37.7%-54.1%), and persons with frailty (36.9%; 95% CI, 30.8%-43.5%) or probable dementia (39.0%; 95% CI, 30.7%-48.1%). In age- and sex-adjusted models with death as a competing risk, the hazard ratios for hospital readmission within 180 days were 2.29 (95% CI, 1.70-3.09) for frailty and 1.58 (95% CI, 1.15-2.18) for probable dementia. In this nationally representative cohort study of community-living older US residents, the likelihood of hospital readmissions within 180 days after major surgery was increased among older persons who were frail or had probable dementia, highlighting the potential value of these geriatric conditions in identifying those at increased risk.

Compare the Centering Ability, Canal Transportation and Root Canal Area Increase of XP Endoshaper, Hyflex CM and K3 XF File System by using Cone Beam: An Original Research

ABSTRACT Objective: Using cone beam computed tomography (CBCT), this study compared three rotary file systems—XP Endoshaper, Hyflex CM, and K3 XF—for centering, canal transportation, and root canal area growth. Materials and Methods: The rotating file system randomly separated 60 removed human mandibular molars into three groups (n = 20). Manufacturer-recommended root canal instrumentation was done. Specialized software examined pre- and post-instrumentation CBCT scans. Centering ability was measured by canal transportation and root canal area expansion at different levels from the apex. Results: The Hyflex CM file system had the best centering and the least canal transit at all levels (P &lt; 0.05). XP Endoshaper increased the root canal area the most (P &lt; 0.05). The K3 XF file system had average centering and canal transfer results. Conclusion: The Hyflex CM system centered well, whereas the XP Endoshaper system increased the root canal area the most. The clinical context and therapeutic goals should determine the rotating file system.

An in vitro evaluation of dentinal microcrack formation during root canal preparations by three different nickel–titanium systems: ProTaper Gold, HyFlex CM, and Silk

Aim: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with three different nickel–titanium (NiTi) systems, namely, ProTaper Gold (PG), HyFlex CM (HCM), and Silk. Methods: One hundred mandibular premolars with a single canal were chosen for this study. All specimens were decoronated and divided into four groups of 25 each. Teeth were mounted in the acrylic block with simulated periodontal ligaments. Group I served as a negative control Group, in which no treatment was performed. Biomechanical preparation was done in the Group II, using the Protaper gold file system. Group III, using the Hyflex CM file system and Group IV, using the Silk file system. Specimens were horizontally sectioned at 3, 6, and 9 mm from the apex using the low-speed diamond disc under water cooling. The slices were then viewed under a stereomicroscope at ×25 to determine the presence of cracks. The absence or presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P &lt; 0.05. Results: Coronal section showed lesser crack formation in all three groups after biomechanical preparation. More number of dentinal microcracks were seen in the apical sections, followed by the middle and the coronal sections in Group II (PG), followed by Group IV (Silk), and Group III (HCM), respectively. Group II showed more microcracks at all three levels of the root canals when compared with Groups III and IV. Intergroup analysis showed no statistically significant difference in microcrack formation. Conclusion: Within the limitation of this in vitro study, it can be concluded that NiTi instruments may cause cracks on the root surface. HCM and Silk files tend to produce a less number of cracks as compared to PG instruments.

Measuring the Amount of Apically Extruded Debris of Endosequence ESR, R-Motion, F6 SkyTaper and Endosequence CM Files in Curved Canals: An in Vitro Study

Aim of the study: Assessing the relationship between Endosequence ESR, R-motion, F6 sky taper and Endosequence CM files use in curved canals and the quantity of apically extruded debris. Materials and methods: 60 curved mesial roots of lower molars with 20-30 degree curvature were selected for this study, The samples were then divided randomly into four groups (n = 15)-Group I: EndoSequence ESR, Group II: R-motion (RM), Group III: F6 SkyTaper and Group IV: EndoSequence CM. This research followed the protocol devised by Myers and Montgomery, wherein debris were collected in vials and weighed before and after instrumentation using a 0.00001-sensitive balance. The instrumentation of all groups was terminated at master apical file #25. Irrigation with 10 ml of deionized water was administered using a needle with a side vent. The collected debris weight was calculated by deducting each vial's pre-instrumentation weight from its post-instrumentation weight. The analysis of variance (ANOVA) and the honestly significant difference (HSD) tests were used to assess the statistical significance of the variation in debris levels across the groups under investigation, using a significance level of 0.05. Results: The results revealed that all tested groups had produced apical debris in different amounts. Conclusions: Under the purview of the present investigation, apical debris was produced in all tested groups. The EndoSequence CM produced less amount of debris than other tested groups. While the RM and F6 SkyTaper produced a comparable amount of apical debris. The EndoSequence ESR produced the most amount of apical debris.

Canal transportation and centering ability of HyFlex CM and TruNatomy rotary file systems in moderately curved root canals using CBCT: An in vitro study

ABSTRACT Aim: The objective of this study was to evaluate and compare canal transportation (CT) and centering ability (CA) in the curved canals prepared using HyFlex CM (HCM) and TruNatomy (TN) rotary file systems with the help of cone-beam computed tomography (CBCT). Materials and Methods: Forty extracted single-rooted mandibular premolars with 10°–30° of curvature were selected and divided into two groups. In Group 1, the canals were prepared with HCM files (Coltene Whaledent) and in Group 2 the canals were prepared with TN Prime rotary files (Dentsply Sirona). Pre- and postinstrumentation scans were performed at the same position using CBCT to evaluate CT and CA at three levels 3 mm, 6 mm, and 9 mm from the apex and were compared using CBCT software (On Demand 3D software). Statistical Analysis Used: The two groups were statistically analyzed with Mann–Whitney U-test. Results: There was no significant difference among the tested groups regarding the canal centering ratio (P &gt; 0.05). At 6- and 9-mm levels, there was no significant difference in CT among the two groups (P &gt; 0.05). However, at 3 mm from apex, there was a statistically significant difference (P = 0.006) with TN files exhibiting lesser CT. Conclusion: Both the file systems respected the canal anatomy, although in the apical third, TN files exhibited better results. Hence, this file system can be considered for instrumentation of canals with moderate apical curvatures. In regard to CA, no significant differences were found among the file systems.

Assessing Percentage of Touched Surfaces and Changes in Cross-sectional Area in Oval Shaped Root Canals after XP-endo Shaper, IRaCe and HyFlex CM Instrumentation Using AutoCAD Software

AIM: This study aimed to calculate the percentage of touched surfaces and changes in the cross-sectional area of oval-shaped root canals after preparation using (XP-endo Shaper, IRace, and HyFlex CM) rotary systems using AutoCAD software. MATERIALS AND METHODS: Sixty extracted single-rooted mandibular premolars were collected and divided into three main groups according to the rotary system used (n = 20). Each tooth was impeded in a resin block, coded, sectioned, and photographed under a stereomicroscope, before and after instrumentation. Microphotographs were analyzed using AutoCAD software. Two-way ANOVA was used to evaluate the mean percentage of the touched surface and mean cross- sectional area between the groups and tooth segments, followed by Tukey’s post hoc test for pair-wise comparisons. RESULTS: The percentage of touched canal walls was significantly different between IRace group and each of XP-endo Shaper and HyFlex CM groups (p &lt; 0.001). A statistically significant difference was recorded for the mean change in the cross-sectional areas of the root canal between IRace group and both HyFlex CM and XP-endo Shaper groups, respectively (p &lt; 0.001). For all groups, there was a significant difference in the change in the cross- sectional area between all segments (coronal, middle, and apical). CONCLUSIONS: Within the limitations of this study, the XP-endo Shaper and HyFlex CM files had a higher cutting efficiency and maintained better root stability than the IRaCe system by preserving the dentin of the oval root canal. This was observed at all the canal levels in the coronal, middle, and apical segments.

Comparative evaluation of the effect of glide path creation with Nitiflex hand K- file, Proglider and Path file on canal transportation and concentricity in apically curved canals - An In- Vitro study.

Abstract&#x0D; Aim:&#x0D; To compare and evaluate the effect of glide path creation with Nitiflex hand K- file, Proglider and Path file on canal transportation and concentricity in apically curved canals.&#x0D; Objectives:&#x0D; To compare the degree of canal transportation and concentricity between:&#x0D; 1) Glide path preparation with Nitiflex hand-K file vs Proglider file followed by combination of Hyflex EDM and CM file instrumentation&#x0D; 2) Glide path preparation with Proglider file vs Path file followed by combination of Hyflex EDM and CM file instrumentation&#x0D; 3) Glide path preparation with Nitiflex hand- K file vs Path file followed by combination of Hyflex EDM and CM file instrumentation&#x0D; Materials and methods:&#x0D; Forty ISO 20, 0.02 taper, Endo Training Blocks (Dentsply Maillefer) were acquired and divided into following four groups (n = 10): group A, Control group without glide path preparation; group B, Glide path preparation with Nitiflex hand-K file; Group C: Glide path preparation with Proglider file; Group D: Glide path preparation with Path files. In all the groups, combination of Hyflex EDM and CM file instrumentation was done after glide path creation. Pre- and post-instrumentation digital images were processed with Image J Version 1.8.0 software to identify the center of the canal, and then superimposed using Adobe Photoshop 7.0 software. Unpaired/independent t test and One Way ANOVA were used for intergroup comparison of difference of mean scores.&#x0D; Results:&#x0D; In comparison to other groups, training blocks instrumented with Proglider files and a combination of Hyflex EDM and CM files had reduced deviation in canal axis.&#x0D; Conclusion:&#x0D; Following the combination of Hyflex EDM and CM file instrumentation with an earlier glide path created with Proglider file, canal concentricity and canal geometry are better preserved.&#x0D; Key words: Glide path, canal transportation, proglider, path files, Hyflex EDM

Comparison of two different file systems on postoperative pain after root canal instrumentation: A randomized controlled trial

Abstract Introduction: In this study post instrumentation pain is evaluated between rotary hyflex CM files and conventional k-files at different time intervals. Methodology: fifty patients were equally assigned into two groups and instrumented using hyflex cm or conventional files. VAS for pain was noted before the start of a root canal and after the procedure at 12, 24, and 48 hours. Results: There was no significant difference at 12, 24, and 48 hours with P values being 0.127, 0.867, and 0.846 respectively. Conclusion: There is no significant difference in causing post-instrumentation pain between hyflex CM and conventional files at different time intervals. However, when accessing preop pain of the conventional file group, it had more pain mean score compared to hyflex group. According to this study, Conventional files may be able to slightly decrease the chances of post-instrumentation pain more than hyflex CM instrumentation.

A cone-beam computed tomographic analysis of total dentin removed, canal transportation, and canal-centering ability following instrumentation with three different file systems: An in vitro study.

The aim of this study was to evaluate the shaping ability following instrumentation with XP-endo Shaper (XPS), TruNatomy (TRN), and HyFlex CM (HCM) file system. Fifty-four mesiobuccal canals of mandibular molars were selected and allocated into three groups randomly: XPS, TRN system, and HCM file system. Pre- and postinstrumentation scans were taken using a cone-beam computed tomography scanner to determine the amount of root dentin removed, mesiodistal and buccolingual transportation, and canal-centering ratio at 2, 5, and 8 mm from the root end. Data were statistically analyzed using Kruskal-Wallis test and the significance level was set at P = 0.05. TRN file system removed the least amount of root dentin. XPS showed statistically higher M-D canal transportation at 5 mm level from the apex. TRN file system showed better dentin preservation as compared to XPS and HCM. XPS showed the highest canal transportation at 5 mm. All three file systems performed similarly in terms of canal-centering ability.

Microtomographic Assessment of the Shaping Ability of the Hyflex CM and XP-endo Shaper Systems in Curved Root Canals.

This study compared the shaping ability of the Hyflex CM and XP-endo Shaper rotary file systems in curved mesial canals of mandibular molars using micro-computed tomography. Seventeen mesial roots of extracted first mandibular molars with two independent mesial canals were scanned before and after root canal preparation with the tested rotatory file systems. Each mesial canal from the same specimen was prepared with one of the two systems. The parameters analyzed were canal centering (transportation) for the cervical, middle, and apical segments, as well as for the entire canal (0-10 mm from the apex); and canal volume increase, canal surface area increase, and unprepared canal walls for two segments, 0 to 4 mm and 0 to 10 mm from the apex. There was no significant difference between both systems regarding canal centering (transportation), volume increase, and unprepared canal walls for the 0 to 10 mm segment (p> 0.05); however, a significant difference was observed for the 0 to 4 mm segment (p <0.01), where the Hyflex CM left 28.46% of unprepared walls and XP-endo Shaper left 13.26%. The shaping ability of the two tested rotatory file systems in mesial roots of first mandibular molars was similar for all parameters in all the segments evaluated, except for the 0 to 4 mm segment, where XP-endo Shaper left a smaller area of unprepared canal walls than Hyflex CM.

Comparison of cyclic fatigue resistance of three different rotary NiTi systems – An in-vitro study

Background: Nickel–titanium (NiTi) alloys created a revolution in the instrumentation of endodontics. However, they undergo unexpected fracture during the instrumentation of curved root canals due to cyclic fatigue. Hence, innumerable scientific and manufacturing researches are focused on fabricating NiTi rotary instruments with greater cutting efficiency and increased fatigue resistance. Aim: The aim of this study is to compare and evaluate the cyclic fatigue resistance of three different NiTi rotary file systems: Hyflex CM, Endostar E3, and Mani Silk. Materials and Methods: In this in-vitro study, 30 Hyflex CM (25/0.06), 30 Mani Silk (25/0.06), and 30 Endostar E3 (25/0.06) instruments were included. The static cyclic fatigue test was performed using a custom-made jig. The artificial canal was made of stainless-steel jig with an inner diameter of 1.5 mm, 45° angle of curvature, and radii of curvature of 5 mm. All the instruments were rotated according to the manufacturer's recommendations until failure occurred. The time taken to failure was recorded in seconds for each group using a digital chronometer. The data were analyzed statistically using the one-way analysis of variance, Post hoc test of Bonferroni was performed to identify pair-wise significance through SPSS 21.0 software (SPSS Inc, Chicago, IL, USA). The statistical significance was set at 5%. Results: Hyflex CM had the statistically highest fatigue resistance followed by Mani Silk and Endostar E3 (P &lt; 0.05). Conclusion: Within the limitations of the present in vitro study, it was found that cyclic fatigue resistance of Hyflex CM files was higher than the cyclic fatigue resistance of Mani Silk and Endostar E3 files.

Comparative evaluation of push-out bond strength of AH-Plus, MTA-Fillapex and Epiphany SE root canal sealers: An Ex-Vivo study.

A successful root canal (RC) treatment depends upon creation of a fluid impervious seal that is commonly built by using a RC sealer along with gutta-percha. The bond strength of the RC sealer is a hallmark as it will minimize the risk of treatment failure by reducing the possibility of filling detachment from dentin. To evaluate and compare the push-out bond strength of AH-Plus and MTA-Fillapex with Gutta-Percha and Epiphany Self Etch/Resilon system using the Universal Testing Machine. About 60 mandibular premolars with single canals were prepared apically with Hyflex CM files upto size #30. Out of total, 20 teeth were obturated with AH-Plus/GP (group 1), 20 with MTA-Fillapex/GP (group 2), and other 20 with Epiphany Self Etch/Resilon system (group 3). Teeth were sectioned into three slices of 2 mm each and were subjected to Universal Testing Machine. The data obtained were tabulated and statistically evaluated using SPSS version 21.0 statistical analysis software (IBM, Chicago, Illinois, USA). The mean push-out bond strength was highest for AH-Plus (14.32 MPa) followed by MTA-Fillapex (12.18 MPa) and then Epiphany SE (8.44 MPa). The results were statistically significant. Significantly, higher push out bond strength was displayed by AH-Plus sealer than MTA-Fillapex and least being Epiphany SE sealer. The push out bond strength was significantly highest at apical third and lowest at coronal third.

Dentinal Defects Induced by Offset and Alternating Contact Endodontic Rotary Files: An In Vitro Study

Objective: Dentinal defects during root canal preparation could lead to treatment failure and tooth extraction. Many rotary files are manufactured with asymmetric cross sections or alternating cutting edges to minimize contact with the canal wall. Decreasing contacts may generate low stresses and, hence, fewer dental defects during root canal instrumentation. This study aimed to evaluate the incidence of dentinal defects induced by ProTaper Next, Wave One Gold (Dentsply Maillefer, Ballaigues, Switzerland), and iRace (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) in comparison to the symmetric file HyFlex CM (Coltene-Whaledent, Allstetten, Switzerland). Materials and Methods: Sixty extracted single-rooted premolars with round canals were selected for this study. All teeth were decoronated and divided into four experimental groups according to the tested file systems. In each group, 15 canals were prepared with the crown down technique using a speed and torque recommended by manufacturers. The root samples were then sectioned horizontally at 3, 6, and 9 mm from the apex and examined under a stereomicroscope to evaluate the presence or absence of dentinal defects. Data were statistically analyzed with SPSS software using a chi-square test. Results: Dentinal defects were observed at all canal levels following all methods of instrumentation. ProTaper Next showed the lowest values of dentinal defects, whereas Hyflex CM displayed the highest values. Conclusion: Files with few contacts with the canal wall decreased the number of dentinal defects compared to the HyFlex CM file, with a nonsignificant difference being observed.

Effect of immersion in sodium hypochlorite on cyclic fatigue resistance of RaCe, HyFlex CM and XP-endo shaper files

This study assessed the effect of sodium hypochlorite on cyclic fatigue resistance of RaCe, HyFlex CM and XP-endo Shaper files. In this in vitro, experimental study, 90 RaCe, HyFlex CM and XP-endo Shaper files (n = 30 of each) were divided into two groups (n = 45). Group 1 included 15 files of each rotary system, which were immersed in 37°C sodium hypochlorite (5.25%) for 5 min. Group 2 files were immersed in 37°C saline for 5 min. The files underwent cyclic fatigue testing using simulated root canals in which, the rotary files could freely rotate until fracture. Time of fracture was recorded by a chronometer and the number of cycles until fracture was calculated. Data were analyzed using two-way ANOVA and Bonferroni test (α = 0.05). No significant difference existed in the mean number of cycles or rotation time of files between saline and sodium hypochlorite (P > 0.05). The mean rotation time of RaCe was significantly shorter than that of HyFlex and XP-endo Shaper in both solutions (P < 0.05). The mean number of cycles of RaCe was significantly lower than that of HyFlex and XP-endo Shaper files in both solutions (P < 0.05). The mean number of cycles of HyFlex was significantly lower than that of XP-endo Shaper (P < 0.05). Immersion of rotary files made of different alloys in 5.25% sodium hypochlorite for 5 min had no effect on their fracture resistance. However, type of file alloy affected its fatigue resistance such that XP-endo Shaper showed the highest and RaCe showed the lowest fatigue resistance.

Retreatment of Experimental Carrier-Based Obturators with the Remover NiTi Instrument: Evaluation of Apical Extrusion and Effects of New Kinematics.

The objective of this study is to evaluate the retreatment time and weight of apically extruded debris yielded by two different kinematics during the removal of different root canal filling materials. Forty straight single-rooted extracted teeth were instrumented with HyFlex CM files and obturated with two different techniques: 25.04 HyFlex experimental carrier-based obturators (Coltène/Whaledent, Altstätten, Switzerland) (group 1) or 25.04 single gutta-percha cones (Roeko Coltène/Whaledent, Altstätten, Switzerland) (group 2) and Guttaflow Bioseal as the sealer. Samples were divided into four subgroups (n = 10) according to the used kinematics for the removal of root canal filling materials: continuous rotation (A) or retreatment motion (B) with a Remover and HyFlex EDM Nickel-Titanium instruments activated with a CanalPro Jeni micromotor (Coltène/Whaledent, Altstätten, Switzerland). Time for retreatment was digitally recorded, and debris extruded from the apex was collected in Eppendorf tubes and weighted with an analytical balance. Data on retreatment time and apical extrusion were statistically analyzed with the Kruskal–Wallis test (p < 0.05). Working length was achieved in all the retreated samples. The removal of root filling material resulted significantly faster with the Jeni mode (p < 0.001), and the difference was significant for the removal of both filling materials (p < 0.05). No significant differences on debris extrusion between single cone and experimental obturators groups were noted (p > 0.05), and no significant differences between kinematics (continuous rotation vs. Jeni motion) were observed (p > 0.05). All the tested retreatment strategies lead to an extrusion of material from the apex, and the weight of apically extruded debris was similar. The use of the innovative CanalPro Jeni kinematics accelerates the time for the removal of root filling materials.

Cone-beam Computed Tomographic Analysis of Canal Transportation and Centering Ability of Three Different Nickel-Titanium Rotary File Systems

AIM: The aim of the present study was to compare the canal transportation and centering ability of three rotary nickel-titanium file systems, HyFlex controlled memory, Revo-S, and Mtwo in moderately curved root canals using computed tomography (CT). MATERIALS AND METHODS: Thirty freshly extracted single-rooted teeth having curved root canals with at least 10°–20° of curvature were selected. The teeth were divided into three experimental groups of ten each. After preparation with HyFlex CM (Coltene-Whaledent, Allstetten, Switzerland), Revo-S (Micro-Mega, Besançon, France), and Mtwo (VDW, Munich, Germany) all teeth were scanned using CT to determine the root canal shape. Pre- and post-instrumentation images were obtained at three levels, 3 mm apical, 9 mm middle, and 15 mm coronal above the apical foramen were compared using CT software. Amount of transportation and centering ability were assessed. The three groups were statistically compared with analysis of variance and post-hoc Tukey’s honestly significant difference test. RESULTS: Least apical transportation and higher centering ability were seen in HyFlex CM file system in all the three sections followed by Revo-S, Mtwo file system showed maximum transportation. CONCLUSIONS: According to the present in-vitro study, we can conclude that HyFlex CM rotary file systems showed least canal transportation and highest centering ability as compared to Revo-S and Mtwo file system but there was no statistically significant difference among these file systems (p &gt; 0.05) at coronal, middle, and apical level of root canal.

An in-vitro comparative study of cyclic fatigue resistance of twisted files, Hyflex cm, Hyflex edm and Edgefile X3 after immersion in sodium hypochlorite and/or sterilization

An in-vitro comparative study of cyclic fatigue resistance of twisted files, Hyflex cm, Hyflex edm and Edgefile X3 after immersion in sodium hypochlorite and/or sterilization - IJCE- Print ISSN No: - 2581-9534 Online ISSN No:- 2581-8988 Article DOI No:- 10.18231/j.ijce.2021.007, IP Indian Journal of Conservative and En

Underrepresentation of pediatric operations in the relative value unit updating process

Background: The Relative Value Unit (RVU) system was designed and implemented by Medicare to standardize physician payments for a given service. Because Medicare primarily cares for older adults, RVU assignments and updates may not consider pediatric-specific procedures, despite the fact that private insurers and Medicaid often base their payments on these RVU valuations.Methods: The CPT codes of index pediatric operations were retrieved from the ACGME. We categorized these procedures into "Peds-specific" (eg, Ladd Procedure) versus those that could be performed in both children and adults, or "Non-specific" (eg, fundoplication). We merged these codes with RVU information from publicly available CMS files and the Resource-based Relative Value Scale Data Manager. Variables included were the date of last RVU update and the vignette used by survey respondents when asked to update the RVU valuation.Results: Among 85 procedures, nearly three-quarters were Peds-specific (74%), with the remainder Non-specific. Approximately half of the 85 procedures (52%) had never been updated. Compared to Non-specific CPT codes, Peds-specific CPT codes were less likely to have been updated (38% vs. 91%, p < 0.001) and, among those that were updated, were updated more remotely (median year 2000 vs. 2005, p = 0.02). Among updated Non-specific CPT codes, the vignette written to justify the valuation was based on an adult patient in 85% of cases.Conclusions: Peds-specific surgical CPT codes have either never been updated or have not been updated in decades. Procedures performed in both children and adults have been updated more often and more recently, but the vignette on which this valuation is based on is typically an adult patient. In order to remain relevant and reimburse pediatric surgeons accurately, the RVUs for pediatric procedures need to also be prioritized for revision and updating.

Cyclic fatigue resistance and shaping ability of heat-treated nickel-titanium instruments after repeated use.

To evaluate the effect of multiple-use and sterilization on cyclic fatigue and shaping ability of heat-treated nickel-titanium (NiTi) rotary instruments. A total of 120 acrylic blocks with S-shaped canals were photographed and prepared by HyFlex CM, ProTaper Next, and Twisted File. Ten new sets of each rotary instruments were used for four times. The autoclaving process was repeated after each use. Pre- and post instrumentation images were superimposed. The amount of resin removal and canal transportation by each system was measured in eleven different points. Instruments were subsequently subjected to a cyclic fatigue test in a double-curved artificial canal. The means and standard deviations of the number of cycles to failure (NCF) were calculated and statistically analyzed (P < 0.05). No fractures occurred during the shaping of the simulated canals. The ProTaper Next removed the greatest amount of resin, whereas the Twisted File had the lowest values at all levels. Repeated clinical use and sterilization resulted in a decrease in the resin removal at most levels in Twisted File and ProTaper Next. In terms of canal transportation, an increase in a limited number of levels was detected after repeated use of all rotary files. Twisted File had the greatest cyclic fatigue resistance, followed by HyFlex CM and ProTaper Next (P < 0.05). The effects of repeated use and autoclaving on the cyclic fatigue resistance of HyFlex CM, ProTaper Next, and Twisted File were not significant. Canal transportation increased mostly in the apical region. The amount of resin removal decreased as the number of use increased for ProTaper Next and Twisted File instruments.