vendex and Smear-Layer

Topics: Dental Alloys; Dental Pulp Cavity; Dentin; Equipment Design; Equipment Failure; Humans; Nickel; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Surface Properties; Terminology as Topic; Time Factors; Titanium; Tooth Apex; Torque

The cleaning effectiveness of automated and manual root canal instrumentation was investigated with the aid of a scanning electron microscope. Hand instrumentation was performed with K-Flexofiles used in a reaming working motion and according to the step-back technique and with Hedstrom files used in a filing motion. Automated preparation was performed with the KaVo-Endo Flash device featuring torque-limited rotation using K-Flexofiles, as well as with the mechanical ProFile system using rotary nickel-titanium instruments. Twelve teeth each with either straight or curved root canals were instrumented to size 40. After cracking the roots longitudinally (n = 120), the amount of debris and smear layer were quantified on the basis of a numerical evaluation scale (1 through 5). Comparison of manual instrumentation with the automated KaVo-Endo Flash resulted in an equivalent degree of canal cleaning. Complete cleanliness was not achieved by any of the techniques and devices investigated. Best instrumentation results, especially in curved canals, were obtained with rotary ProFile instruments.

Topics: Automation; Dental Alloys; Dental Pulp; Dental Pulp Cavity; Dentin; Equipment Design; Humans; Microscopy, Electron, Scanning; Nickel; Root Canal Preparation; Rotation; Smear Layer; Statistics, Nonparametric; Titanium; Tooth Apex; Torque

The purpose of this study was to compare the in vitro amount of apically extruded debris with new endodontic rotary nickel-titanium instruments.. Sixty mandibular premolars were instrumented up to size 25 using ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Next (Dentsply Maillefer), Twisted File Adaptive (SybronEndo, Orange, CA), and HyFlex (Coltene-Whaledent, Allstetten, Switzerland) rotary systems. The apically extruded debris was collected and dried in preweighed Eppendorf tubes. The amount of extruded debris was assessed with an electronic balance. The total time required to complete root canal shaping with the different instruments was also recorded. The significance level was set at P = .05.. The instrumentation time with the ProTaper Universal rotary system was significantly longer than with all the other instruments (P < .05). The Twisted File Adaptive and ProTaper Next systems extruded significantly less debris than the ProTaper Universal and HyFlex systems (P < .05).. The ProTaper Next and Twisted File Adaptive instrumentation systems were associated with less debris extrusion compared with the ProTaper Universal and HyFlex systems.

Topics: Adult; Bicuspid; Dental Alloys; Dental Pulp Cavity; Equipment Design; Humans; Materials Testing; Middle Aged; Nickel; Periapical Tissue; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Therapeutic Irrigation; Time Factors; Titanium; Tooth Apex; Torque

In this study, curved maxillary molar root canals were instrumented with RaCe rotary system to evaluate: 1. the occurrence of canal transportation using a radiographic platform; 2. the action of the instruments on the dentin walls, centering ability and canal enlargement by analysis of digital images; and the percentage of regular dentin surfaces and debris within the canal by histological analysis. Ten mesiobuccal roots of extracted human maxillary molars were embedded in acrylic resin and sectioned at the middle and apical thirds. Root canal shaping was performed using the RaCe rotary system at 250 rpm and 1 Ncm torque. Each instrument set was used five times according to a crown-down technique in the following sequence: 40/0.10, 35/0.08, 25/0.06, 25/0.04, 25/0.02 (working length - WL), 30/0.02 (WL) and 35/0.02 (WL). Each instrument was inserted until resistance was felt and then pulled back, followed by brushing movements towards all canal walls. Each specimen was assessed by three study methods: radiographic platform, digitized image assessment and histological analysis. The radiographic platform showed lack of apical transportation. No statistically significant difference (Wilcoxon test, p>0.05) was found between the middle and apical thirds regarding instrument action on dentin walls, centering ability, area of root canal enlargement, percentage of regular dentin surfaces and debris within the root canal. It may be concluded that RaCe system is a suitable method for the preparation of curved root canals, regarding the maintenance of root canal original path, action on dentin walls, canal enlargement and removal of debris from the root canal lumen.

Topics: Dental Pulp Cavity; Dentin; Equipment Design; Humans; Image Processing, Computer-Assisted; Materials Testing; Molar; Radiography; Root Canal Preparation; Rotation; Smear Layer; Tooth Apex; Torque

The purpose of this study was to evaluate the weight of debris extruded apically from teeth using different in vitro preparation techniques.. Sixty-eight extracted human mandibular premolars with single canals and similar lengths were instrumented using ProTaper F2 (25, .08; Dentsply Maillefer, Ballaigues, Switzerland), the Self-Adjusting File (1.5-mm diameter; Re-Dent Nova, Ra'anana, Israel), Revo-S SU (25, .06; MicroMega, Besancon, France), or Reciproc (R25; VDW GmbH, Munich Germany). Debris extruded during instrumentation were collected into preweighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70°C for 5 days. The Eppendorf tubes were weighed to obtain the final weight of the Eppendorf tubes when the extruded debris were included. Three consecutive weights were obtained for each tube.. There were no statistically significant differences among the groups (P = .218). The ProTaper group produced the highest mean extrusion value. The Reciproc produced less debris compared with all the other instruments (P > .05).. All instrumentation techniques were associated with extruded debris.

Topics: Bicuspid; Dental Pulp Cavity; Equipment Design; Humans; Materials Testing; Pressure; Root Canal Preparation; Rotation; Smear Layer; Tooth Apex; Torque; Vibration

To compare shaping ability and cleaning effectiveness of two reciprocating single-file systems with Mtwo and ProTaper rotary instruments during the preparation of curved root canals in extracted teeth.. A total of 80 root canals with curvatures ranging between 25° and 39° were divided into four groups of 20 canals. Based on radiographs taken prior to instrumentation, the groups were balanced with respect to the angle and the radius of canal curvature. Canals were prepared to the following apical sizes: Mtwo: size 35 using the single-length technique; ProTaper: F3, instruments were used in a modified crown-down manner; Reciproc and WaveOne: size 25. Using pre- and post-instrumentation radiographs, straightening of the canal curvatures was determined with a computer image analysis program. Preparation time and instrument failures were also recorded. These data were analysed statistically using anova and Student-Newman-Keuls test. The amounts of debris and smear layer were quantified on the basis of a numerical evaluation scale and were analysed statistically using the Kruskal-Wallis test.. During preparation no file fractured. All instruments maintained the original canal curvature well with no significant differences between the different files (P = 0.382). Instrumentation with Reciproc was significantly faster than with all other instruments (P < 0.05), while WaveOne was significantly faster than Mtwo and ProTaper (P < 0.05). For debris removal, Mtwo and Reciproc instruments achieved significantly better results (P < 0.05) than the other instruments in the apical third of the canals. In the middle and coronal parts, no significant differences were obtained between Mtwo, Reciproc and WaveOne (P > 0.05), while ProTaper showed significantly more residual debris (P < 0.05). The results for remaining smear layer were similar and not significantly different for the different parts of the canals (P > 0.05).. Under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. The use of Mtwo and Reciproc instruments resulted in better canal cleanliness in the apical part compared with ProTaper and WaveOne.

Topics: Dental Pulp Cavity; Dentin; Equipment Design; Equipment Failure; Humans; Image Processing, Computer-Assisted; Materials Testing; Radiography; Root Canal Preparation; Rotation; Smear Layer; Surface Properties; Time Factors; Tooth Apex; Tooth Cervix; Torque

To compare various parameters of root canal preparation using RaCe (FKG Dentaire, La-Chaux-de-Fonds, Switzerland) and ProTaper (Dentsply Maillefer, Ballaigues, Switzerland) nickel-titanium (Ni-Ti) instruments.. Fifty extracted mandibular molars with mesial root canal curvatures between 20 degrees and 40 degrees were embedded in a muffle system. All root canals were prepared to size 30 using RaCe or ProTaper rotary instruments in low-torque motors with torque control and constant speed of 300 r.p.m. (ProTaper with ATR Tecnika, Advanced Technology Research, Pistoia, Italy; RaCe with EndoStepper, S.E.T., Olching, Germany). In both groups irrigation was performed with 2 mL NaOCl (3%) after each instrument size. Calcinase-Slide (lege artis, Dettenhausen, Germany) was used as a chelating agent with each instrument. The following parameters were evaluated: straightening of curved root canals, postoperative root canal cross-sections, safety issues and working time. Cleanliness of the root canal walls was investigated under the SEM using 5-score indices for debris and smear layer. Statistical analysis was performed using the following tests: Wilcoxon's test for straightening and working time was used (P < 0.05); Fisher's exact test for comparison of cross-sections and root canal cleanliness (P < 0.05).. Both Ni-Ti systems maintained curvature well; the mean degree of straightening was less than 1 degrees for both systems. Following preparation with RaCe, 49% of the root canals had a round or oval diameter and 50% an irregular diameter, ProTaper preparations resulted in a round or oval diameter in 50% of the cases. For debris, RaCe and ProTaper achieved 47 and 49% scores of 1 and 2, respectively; there was no significant difference. For smear layer, RaCe and ProTaper achieved 51 and 33% scores 1 and 2, respectively; no statistically significant differences were apparent for the coronal and middle sections of the root canals, but RaCe performed significantly better in the apical region (Fisher's exact test, P = 0.0392). Two roots lost working length with RaCe instruments, whilst ProTaper preparation resulted in two roots loosing working length and one fractured instrument. Mean working time was shorter for ProTaper (90.9 s) than for RaCe (137.6 s); the difference was significant (Wilcoxon's test, P = 0.011).. Both systems respected original root canal curvature well and were safe to use. Cleanliness was not satisfactory for both systems.

Topics: Dental Alloys; Dental Instruments; Equipment Failure; Humans; Molar; Nickel; Root Canal Preparation; Smear Layer; Stainless Steel; Titanium; Torque

To compare several parameters of root canal preparation using two different rotary nickel-titanium (Ni-Ti) instruments: FlexMaster (VDW, Munich, Germany) and HERO 642 (Micro-Mega, Besançon, France).. Fifty extracted human mandibular molars with root canal curvatures between 20 and 40 degrees were embedded into a muffle system. All root canals were prepared to size 45 using a high-torque motor with two different Ni-Ti instruments, FlexMaster and HERO 642. In both groups, irrigation was performed with 2 mL NaOCl (3%) after each instrument size. RC-Prep (Premier, Philadelphia, USA) was used as a chelating agent with each instrument. The following parameters were evaluated: straightening of curved root canals, postoperative root canal diameter, working safety (file fractures, perforations, apical blockages, loss of working length), cleaning ability and working time. Statistical analysis was performed using the Wilcoxon's test (P < 0.05) for straightening and Fishers's exact test (P < 0.05) for comparison of cross-sections, contact between pre- and postoperative diameter, root canal cleanliness and working time.. Both Ni-Ti systems maintained the curvature well: the mean degree of straightening was 0.6 degrees for FlexMaster and 0.5 degrees for HERO 642. One file was fractured with the FlexMaster system, but further procedural incidents were not recorded. Following preparation with FlexMaster, 18% of the root canals had a round diameter, 53% an oval diameter and 29% an irregular diameter; HERO 642 preparations resulted in a round diameter in 25%, oval shape in 47% and irregular cross-sections in 28% of the cases. Mean working time was shorter for HERO 642 (66.0 s) than for FlexMaster (71.1 s). Cleanliness of the root canal walls was investigated under the SEM using 5-score indices for debris and smear layer. For debris, HERO 642 and FlexMaster achieved 73 and 70% scores of 1 and 2, respectively. The results for smear layer were similar: HERO 642 and FlexMaster achieved 33 and 26% scores of 1 and 2, respectively. Significant differences between the two systems were not detected for any of the parameters evaluated.. Both systems respected original root canal curvature well and were safe. Both systems failed to remove debris and smear layer in the majority of the cases.

Topics: Chelating Agents; Dental Alloys; Dental Pulp Cavity; Dentin; Disinfectants; Edetic Acid; Equipment Design; Equipment Failure; Equipment Safety; Humans; Microscopy, Electron, Scanning; Nickel; Peroxides; Root Canal Irrigants; Root Canal Preparation; Rotation; Smear Layer; Sodium Hypochlorite; Statistics, Nonparametric; Time Factors; Titanium; Torque; Urea; Waxes

The cleaning capacity of mechanical endodontic instruments activated by the ENDOflash system was evaluated by means of histologic and morphometric analyses. Twenty-two distobuccal roots of human maxillary molars from laboratory stock were randomly separated into four groups. Group 1 was instrumented with ENDOflash files, group 2 with ProFile taper .04 files, group 3 received instrumentation with Pow-R taper .04 files, and group 4 (positive control) was instrumented with Nitiflex files. After instrumentation, teeth were sectioned transversally and processed for microscopic evaluation to determine the amount of debris on root canal walls. Results obtained by morphometric analysis indicated significant statistical differences (p < 0.01) between groups. ProFile taper .04 files were significantly more efficient in cleaning the root canal, followed by Pow-R files, Nitiflex, and ENDOflash, which had the lowest levels for cleaning the root canals.

Topics: Analysis of Variance; Dental Alloys; Dental Instruments; Equipment Design; Humans; Molar; Nickel; Random Allocation; Root Canal Preparation; Smear Layer; Stainless Steel; Titanium; Torque