Canal Surface Area Research Articles

Root canal preparation in mandibular premolars with TRUShape and Vortex Blue: A micro-computed tomography study.

A comparison of the preparation ability of two root canal instrumentation systems in oval-shaped canals using micro-computed tomography was undertaken. Thirty extracted, single-rooted, human mandibular premolars with radiographically similar canal morphology were selected, allocated to two groups (N=15) and prepared with TRUShape or Vortex Blue (VB). Each sample was subjected to three scans (20μm resolution): pre-preparation and after preparation to sizes #30 and #40. Three-dimensional data sets were evaluated for canal volume, surface area and surface treatment. Matched axial slices in apical, middle and coronal root thirds were evaluated for cross-sectional area, roundness and transportation. Preparation with both instruments increased canal volumes and surface areas similarly and significantly (P<0.001) with no significant difference between groups. TRUShape significantly enhanced surface treatment at both apical sizes (P<0.05). Transportation exceeded 100μm in only eight out of 90 cross sections. Both instruments performed similarly during preparation. TRUShape, however, significantly enhanced surface treatment.

Shaping properties and outcomes of nickel-titanium rotary and reciprocation systems using micro-computed tomography: a systematic review.

This systematic review aims to discuss the shaping properties and outcomes of nickel-titanium (NiTi) rotary and reciprocation systems assessed by micro-computed tomography. A literature search was conducted in PubMed and SCOPUS database until April 2018 to identify investigations examining the shaping properties and outcomes of rotary and reciprocation NiTi systems using micro-computed tomography. In addition, a quality assessment was undertaken for the included studies. A total of 1,110 titles were identified in the literature search. After removal of duplicates, 25 studies satisfied the inclusion criteria. Quality assessment showed that 17 studies were of low risk of bias. Six shaping properties and outcomes including centering ability, transportation, untouched canal walls, canal surface area and volume, microcrack formation, and debris accumulation were discussed. The use of the same system in rotary or reciprocation motions and reciprocating single file systems have comparable transportation and centering ability. No difference was observed between rotary and reciprocation systems/motions in surface area and volume of the canal changes. Untouched canal walls and accumulation of debris remained controversial. No relationship was found between kinematics of instrumentation and the formation of dentinal cracks.

Shaping Ability of HyFlex EDM and ProTaper Next Rotary Instruments in Curved Root Canals: A Micro-CT Study

The aim of this study is to evaluate and compare the shaping ability of HyFlex™ EDM (HFEDM) and ProTaper Next (PTN) rotary instruments in curved root canals by using micro-computed tomography (micro-CT) imaging. A total of 22 mandibular molar teeth having separate mesial canals with 20 to 30° curvatures were randomly divided into two groups and instrumented with HFEDM (OneFile) or PTN (X1 and X2). Pre- and post-instrumentation micro-CT scans were obtained. Mesiodistal canal transportation and centering ability were evaluated in four cross-sections (2, 4, 6, and 8 mm from apex). Changes in canal volume and surface area were measured for a 10-mm standardized area of interest. Kolmogorov-Smirnov and Shapiro-Wilk tests were used to assess the normality and homogeneity. Independent and paired t tests and one-way ANOVA were used to analyze data at the p < 0.05 level. Compared to PTN, HFEDM showed significantly less mesiodistal canal transportation and improved centering ability in cross-section L6 (p < 0.05). The instruments showed similar increases in volume and surface area of the canals, with minor insignificant differences. HFEDM and PTN files were safe to use in curved canals and showed similar shaping ability, while respecting the original anatomies. HFEDM OneFile performed better at the vicinity of the danger zone in terms of mesiodistal canal transportation and centering ability.

Unprepared root canal surface areas: causes, clinical implications, and therapeutic strategies.

Chemomechanical preparation is intended to clean, disinfect, and shape the root canal. This step is of utmost importance during treatment of infected teeth with apical periodontitis, because treatment outcome depends on how effectively the clinician eliminates bacteria, their products, and necrotic tissue that would serve as substrate for bacterial regrowth. Nonetheless, curvatures and complex internal anatomical variations of the root canal system can pose a high degree of difficulty in reaching these goals. In infected teeth, bacteria may persist not only in difficult-to-reach areas such as isthmuses, ramifications, dentinal tubules, and recesses from C-shaped or oval/flattened canals, but also in areas of the main canal wall that remain untouched by instruments. If bacteria withstand chemomechanical procedures, there is an augmented risk for post-treatment apical periodontitis. This article discloses the reasons why some areas remain unprepared by instruments and discusses strategies to circumvent this issue and enhance infection control during endodontic treatment/retreatment of teeth with apical periodontitis.

Micro–computed Tomography Shaping Ability Assessment of the New Blue Thermal Treated Reciproc Instrument

IntroductionThe present study aimed to assess canal preparation outcomes achieved by the new Reciproc Blue instrument using micro–computed tomography technology. M-Wire Reciproc was used as a reference instrument for comparison. MethodsSeven pair-matched mesial roots of mandibular molars presenting similar anatomic features of the canal (length, volume, surface area, and configuration) were selected after scanning procedures and assigned to 1 of the 2 groups according to the instrument used, M-Wire Reciproc and Reciproc Blue. After canal instrumentation, the specimens were rescanned, and the registered preoperative and postoperative datasets were examined to evaluate the percentages of removed dentin, untouched canal walls, and degree of canal transportation. Comparisons regarding the above outcomes between the 2 groups were done by using paired t test with the alpha-type set at 5%. ResultsRoot canals prepared with conventional M-Wire Reciproc or Reciproc Blue were found to present similar shaping properties with no significant differences in the tested parameters. ConclusionsM-Wire Reciproc and Blue Reciproc presented similar shaping outcomes.

Efficacy of different irrigation techniques on calcium hydroxide removal from the root canal

Summary Introduction Calcium hydroxide (CH) is a medicament widely used in endodontic treatment due to its antibacterial, regenerative and biocompatible properties. Studies have shown that remaining CH on root canal walls and dentinal tubules can compromise sealer penetration, leading to its weak adhesion, volume change and, consequently, apical leakage. The aim of this study was to compare the efficacy of four different techniques in removing calcium hydroxide from the root canal. Material and Methods 32 extracted single-rooted teeth with one canal were used in this study. The canals were prepared using BioRaCe system (FKG Dentaire, Swiss) BR5 40/.04 with sodium hypochlorite irrigation after each instrument. Longitudinal grooves were formed on the proximal root surfaces. All canals (except negative control) were filled with aqueous CH suspension. After seven days of incubation, the teeth were allocated into the four groups (n=7), plus positive and negative control. Four techniques (systems) for CH removal were tested: conventional syringe irrigation (CSI), passive ultrasonic irrigation (PUI), XP-endo Finisher (FKG Dentaire, Swiss) and Canal Brush (Roeko, Coltene) with irrigation of 5 ml 2% NaOCl and 5 ml 10% citric acid. All the roots were then split into the two halves with chisel and observed under the stereomicroscope (Boeco, Germany) at magnification of 20x. The area with remaining CH on the root canal wall surface was then divided with the total root canal surface area (%). The obtained results were statistically processed using One-way ANOVA and Tukey post-hoc test (p&lt;0.05). Results The most efficient system was XP-endo Finisher with 91.33% of clean surface, followed by PUI 88.36%, Canal Brush 87.83%, and CSI with 66.92%. Conclusion None of the systems completely removed the traces of the medicament from the root canal. For optimal clinical success, it is necessary to combine various systems with copious irrigation.

Mandibular mesial root canal morphology using micro-computed tomography in a Brazilian population.

To assess the root canal system morphology of mandibular molars by means of micro-computed tomography, one hundred and four mandibular first molars were investigated and the following were evaluated: Vertucci's classification, the presence of lateral canals and the number of apical foramina. Mesial root canal surface area and volume were obtained by the CTAn and CTvol software. The type of root canal isthmi was classified applying the Hsu & Kim and Fan criteria. The most frequent root canal configuration was Vertucci type IV (46.2%). Lateral canals were observed in all root canal thirds and the average number of apical foramina was 3.15 ± 1.77. Regarding the presence of isthmus, Types I and II were the most prevalent, according to Hsu & Kim and Fan et al. criteria, respectively. Mesial root canals of mandibular molars showed high morphology variability.

Comparative evaluation of the shaping ability of single-file system versus multi-file system in severely curved root canals

Background/purposeReciprocating single-file systems are the latest nickel-titanium instruments and little information is available concerning the shaping ability of these new systems. Comparison of these single-file systems with well-known rotary multi-file systems is necessary. The purpose of this study was to compare the shaping ability of single-file system (WaveOne, WO) versus multiple-file system (ProTaper Next, PTN) in severely curved canals. Materials and methodsA total of 20 severely curved canals were prepared with WO or PTN. Micro-computed tomography was used to scan the specimens before and after instrumentation. Differences between two groups in canal surface area, volume, Structure Model Index (SMI), thickness, straightening, the ratio of uninstrumented surface area and canal transportation were evaluated. ResultsThe outline of the canals after preparation showed smooth taper in both groups. Canal surface area, volume, SMI, Thickness and canal curvature were significantly increased after preparation in both groups, and no significant difference was found between groups. At apical third, canals prepared with WO showed larger values of transportation compared with those in PTN group in the direction of main curvature. Approximately 29–34% of the root canal surface remained uninstrumented after preparation and no significant difference was noticed between groups. ConclusionBoth of the two instrument systems maintained the original outline of the canals well. The canals prepared with PTN had less transportation and were better centered in the apical region.

Influence of Contracted Endodontic Access on Root Canal Geometry: An In Vitro Study

IntroductionContracted endodontic cavities (CECs) have developed from the concept of minimally invasive dentistry and provide an alternative to traditional endodontic cavities (TECs). They have been designed in an effort to preserve the mechanical stability of teeth. The contracted cavity design preserves more of the dentin but may influence the geometric shaping parameters. The aim of this micro–computed tomographic study was to evaluate the influence of contracted endodontic cavities on the preservation of the original root canal anatomy after shaping with nickel-titanium rotary instruments. MethodsThirty extracted human mandibular molars with fully formed apices and independent mesial canals were randomly assigned to group 1 (TEC) and group 2 (CEC). Each group was shaped using ProGlider (Dentsply Maillefer, Ballaigues, Switzerland) and WaveOne Gold (Dentsply Maillefer). Irrigation was performed with 10% EDTA and 5% sodium hypochlorite. Samples were scanned before and after canal shaping to match canal volumes (SkyScan; Bruker microCT, Kontich, Belgium [100 kV, 100 μA, and 15-μm resolution]), and images were analyzed to evaluate canal volumes, surface areas, and centroid shift on cross sections at −1 mm and −3 mm from the apex. ResultsTECs showed a greater preservation of the original root canal anatomy with less apical transportation than CECs, possibly because of the absence of coronal interferences and, therefore, fewer pecking motions required to complete instrumentation. ConclusionsWithin the limitations of this study, TECs may lead to a better preservation of the original canal anatomy during shaping compared with CECs, particularly at the apical level.

The internal root canal morphology of single-rooted mandibular canines revealed by micro-computed tomography

Context:The lack of thorough knowledge regarding morphological and anatomical variations of the root canal system can result in failure to identify all root canals and lead to inadequate instrumentation and consequent failure of the endodontic treatment.Aims:The aim of the study was to evaluate the anatomy of single-rooted mandibular canines using micro-computed tomography (micro-CT).Subjects and Methods:Eighty mandibular canines were scanned by micro-CT to determine anatomic parameters: Vertucci's classification, number of lateral canals, roundness, and minor and major diameters. The shape of root canal orifices, volume, surface area, and convexity structure model index (SMI) were also evaluated.Analysis Used:The CTAn and CTvol software were used to three-dimensional and morphometric analysis.Results:All canals were classified as Vertucci Type I. Lateral canals were verified in 42.4% of the roots, in apical third. The canal diameters were decreased near the apex. The cross sections at the cementoenamel junction and 1 mm from the apex were oval in 38.3% and 79.4% of the canals, respectively. The mean canal volumes and surface areas were 11.48 ± 4.41 mm3≥ and 67.29 ± 19.18 mm2, respectively. The SMI values indicated that mandibular canine was approximately rod like.Conclusions:The morphology of the root canal of single-rooted canines varied widely at different root levels.

Effects of increased apical enlargement on the amount of unprepared areas and coronal dentine removal: a micro-computed tomography study.

To evaluate the effects of progressive apical enlargement on the amount of unprepared root canal surface area and remaining dentine thickness. The root canals of 30 extracted mandibular incisors with Vertucci's type I configuration were instrumented with rotary HyFlex CM instruments (Coltene-Whaledent, Altstätten, Switzerland) up to 4 instruments larger than the first one that bound at the working length (WL). Teeth were scanned in a micro-computed tomography (micro-CT) device before canal preparation and after instrumentation with the 2nd, 3rd and 4th larger instruments. The amount of unprepared surface area in the full canal or in the apical 4mm as well as the remaining dentine thickness at 10mm from the WL were calculated and compared. The general linear model for repeated measures adjusted by Bonferroni's post hoc test was used for statistic analysis. There was a significant reduction in the amount of unprepared areas after each increase in preparation size (P<0.01). This was observed for both the full canal length and the 4-mm apical segment. The amount of remaining dentine was also significantly reduced after each file size (P<0.01). However, dentine thickness always remained greater than 1mm, even after using the largest instrument. Apical preparations up to 4 instruments larger than the first one to bind at the WL caused a significant progressive reduction in the unprepared canal area.

Influence of Artifact Reduction Tools in Micro–computed Tomography Images for Endodontic Research

IntroductionMicro–computed tomography (μCT) is an imaging modality of growing application in endodontic research because of its nondestructive technology that enables visualization at the micrometer level. In the presence of high-density material, images acquired with μCT may present artifacts. Thus, the aim of this study was to evaluate subjectively and objectively the influence of artifact reduction tools available for μCT image reconstruction to determine whether their use can influence endodontic research outcomes. MethodsTen teeth were scanned in a μCT device, and these images were reconstructed by applying 13 protocols of artifact reduction tools, combining ring artifact reduction (RAR) and beam-hardening artifact reduction (BAR). Images were assessed subjectively (observer's preference) and objectively (root canal surface area and volume). Observer's preference for RAR and BAR protocols was tested by χ2. Analysis of variance was used to compare volumes and surface area of root canals on different protocols. Intraobserver and interobserver reproducibility was calculated by the weighted kappa test. ResultsThere was no preference for a particular protocol for BAR (P = .91) or RAR (P = .80). There were no statistically significant differences for volume (P = .999) or surface area (P = .972) of root canals for all protocols. ConclusionsTo evaluate root canal volume and root canal surface area, artifact reduction tools applied to μCT images can be used according to the observer's visual preference without influence on objective image analysis.

Micro-CT Evaluation of Root and Canal Morphology of Mandibular First Premolars with Radicular Grooves.

The aim of this study was to evaluate morphological features of 70 single-rooted mandibular first premolars with radicular grooves (RG) using micro-CT technology. Teeth were scanned and evaluated regarding the morphology of the roots and root canals as well as length, depth and percentage frequency location of the RG. Volume, surface area and Structure Model Index (SMI) of the canals were measured for the full root length. Two-dimensional parameters and frequency of canal orifices were evaluated at 1, 2, and 3 mm levels from the apical foramen. The number of accessory canals, the dentinal thickness, and cross-sectional appearance of the canal at different root levels were also recorded. Expression of deep grooves was observed in 21.42% of the sample. Mean lengths of root and RG were 13.43 mm and 8.5 mm, respectively, while depth of the RG ranged from 0.75 to 1.13 mm. Mean canal volume, surface area and SMI were 10.78 mm3, 58.51 mm2, and 2.84, respectively. Apical delta was present in 4.35% of the sample and accessory canals were observed mostly at the middle and apical thirds. Two-dimensional parameters indicated an oval-shaped cross-sectional appearance of the root canal with a high percentage frequency of canal divisions (87.15%). Canal configuration type V (58.57%) was the most prevalent. C-shaped configuration was observed in 13 premolars (18.57%), whereas dentinal thickness ranged from 1.0 to 1.31 mm. Radicular grooves in mandibular first premolars was associated with the occurrence of several anatomical complexities, including C-shaped canals and divisions of the main root canal.

XP Shaper, A Novel Adaptive Core Rotary Instrument: Micro–computed Tomographic Analysis of Its Shaping Abilities

IntroductionThe aim of this study was to investigate the shaping abilities of the XP Shaper (FKG, La Chaux-de-Fonds, Switzerland) and compare the findings with Vortex Blue (Dentsply Tulsa Dental Specialties, Tulsa, OK) using micro–computed tomographic imaging. MethodsTwenty matched, extracted, mandibular, central incisors with a single, oval canal were scanned preoperatively at 25-μm resolution and postoperatively after instrumentation with either Vortex Blue in a crown-down manner up to size 30.04 or XP Shaper. The percent of untouched walls, changes in canal volume and surface area, the amount of dentin removed, debris remaining in the canal, and the preparation taper were determined. The total time required for instrumentation using each technique was calculated in seconds. Statistical analysis was used to compare between both groups using repeated measures multivariate analysis of variance with Bonferroni correction for post hoc comparison and independent sample t tests. ResultsThe XP Shaper significantly increased the canal volume (F = 77.948, P < .001), surface area (F = 5.543, P = .030), and amount of dentin removed (F = 10.044, P = .001) and had significantly less untouched walls (38.6% ± 8.1%) compared with VB (58.8% ± 8.5%). There was less debris at all levels of the canal in the XP Shaper group. Results were almost significant (P = .059). The XP Shaper was also significantly faster in completing the mechanical preparation of the root canal space by almost 1 minute (t = 6.216, P < .001). ConclusionsThe XP Shaper can expand beyond its core size to adapt to the anatomy of the root canal space. The XP Shaper can prepare and touch more canal walls in oval-shaped canals compared with Vortex Blue. However, the final preparation taper will vary according to the anatomy of the treated tooth.

Preparation of Oval-shaped Canals with TRUShape and Reciproc Systems: A Micro–Computed Tomography Study Using Contralateral Premolars

IntroductionThe purpose of this study was to compare the shaping properties of TRUShape and Reciproc systems during preparation of oval-shaped canals from contralateral teeth by using micro–computed tomography scanning. MethodsThirteen pairs of freshly extracted contralateral mandibular premolars with a single oval-shaped canal were selected and divided into 2 groups according to the root canal instrumentation technique, TRUShape and Reciproc. The final apical size of instrumentation was 40/.06 for both systems. Data were statistically analyzed for the increase in canal volume and surface area and the amount of unprepared areas promoted by the 2 systems. ResultsPreparation with both systems significantly increased the volume and area of the canals (P < .001), with no significant differences between them (P > .05). When the full canal length was evaluated, the amount of uninstrumented areas was significantly larger for Reciproc (30%) than TRUShape (24%) (P < .05). However, analysis restricted to the apical 4-mm segment revealed no statistically significant difference in untouched areas (25% for Reciproc and 20% for TRUShape) (P > .05). ConclusionsBoth instrument systems behaved similarly in promoting the increase of root canal volume and surface area. When the full canal length was evaluated, TRUShape instruments showed less unprepared areas than Reciproc. However, this difference did not occur for the apical part of the root canal. None of the techniques could completely prepare oval-shaped root canals.

EFFICACY OF XP-ENDO FINISHER, PASSIVE ULTRASONIC IRRIGATION, VIBRINGE AND CONVENTIONAL SYRINGE IRRIGATION ON DEBRIS REMOVAL IN OVAL ROOT CANALS: A COMPARATIVE STUDY

Introduction: The purpose of this study was to evaluate the efficacy of XP- Endo finisher (XP) (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) on removal of debris from coronal, middle and apical thirds of oval root canals in comparison to passive ultrasonic irrigation (PUI), vibringe (VB) and conventional syringe irrigation (CSI).Methods: Eighty extracted single-rooted human mandibular premolars were used in this study. Specimens with a standardized length of 16 mm were mechanically prepared with Race (FKG Dentaire) till # 40/4%. Teeth were divided into 4 groups (n=20) according to the final irrigant activation protocol into the following groups: CSI, PUI, XP and VB. Root canals were then split longitudinally. Digital images were acquired to evaluate the amount of debris by using a digital camera mounted on a stereomicroscope at 25x magnification and transferred to the computer and scored in mm2 and recorded as a percentage of the overall canal surface area by using image analysis software. Debris percentage was analyzed by One-way ANOVA. Results: The XP and PUI groups revealed significantly lower debris percentage than the other groups in the coronal, middle, and apical regions (P≤0.05). There was no statistically significant difference between XP and PUI. Regarding all systems the coronal third was cleaner than the apical thirds. Conclusions: In our study, none of the activation systems completely removed the debris from the root canal walls; nevertheless, the XP and PUI showed the best results along all thirds in comparison to the other systems.

EFFICACY OF RECIPROC R40 AND REVO-S IN PREPARATION OF OVAL ROOT CANALS- AN EX-VIVO CONE BEAM COMPUTED TOMOGRAPHY STUDY

Aim: To evaluate the efficacy of Revo-S and Reciproc R40 NiTi files in preparation of oval root canals using Cone Beam Computed Tomography (CBCT). Methodology: Forty extracted single rooted premolars were divided into 2 groups (n=20). Group 1 (R-S) were prepared with Revo-S up to size #40/.06. Group 2 (R40) were prepared to the same size with a single file R40. Pre- and post-instrumentation CBCT scanning was done. Calculated parameters were: increase (D) in canal volume and surface area. Transportation, centering ability, and untouched canal areas were tested at 3, 6, 9 mms axial sections. Statistical analyses were made using Mann-Whitney U and Friedman’s test (P ≤ 0.05). Results: Significant increase in D volume (P =.000 and P=.003 for R-S and R40 respectively) and D surface area (P =0.048 and P =0.038 for R-S and R40 respectively) was found for both instrumentation kinematics with no significant differences between them. Canals’ transportation and decreased centering ratio were detected in both groups at all tested levels with insignificant smaller values in the M-D direction. Exception was found at 9mm level where a significantly highest transportation was found in R-S group (P= 0.022). Both instruments left untouched canal areas which were insignificantly greater in R-S group (26.5 ± 8.93% for R40 and 31.7 ± 4.96% for R-S). Conclusions: The tested systems caused small canal transportation with a comparatively better centering for Reciproc R40. Irrespective of the instrumentation kinematic, circumferential preparation of oval canals remains an inherent incapability. CBCT is a valuable tool allowing calculation of the canals’ volume.

Extent of Decompression of Lumbar Spinal Canal after Endoscopic Surgery.

Introduction Endoscopic techniques are being used in lumbar disk disease and lumbar canal stenosis to decompress the spinal canal. The present study analyzed pre- and postoperative magnetic resonance imaging (MRI) measurements of the lumbar canal. Material and Methods This was a prospective study of 30 lumbar levels. Patients < 18 years of age with unilateral compression, previous surgery at the same level, and spinal instability were excluded. Endoscopic posterior decompression was used. Pre- and postoperative MRIs of all the patients were performed. Anteroposterior (AP), transverse, interfacet diameter, canal surface area, and height and angle of the lateral recess were measured. Results Mean ages of male and female patients were 42.1 ± 10.3 and 45.0 ± 9.9 years, respectively. Pathologies were at L4-L5, L5-S1, and L2-L3 levels in 16, 13, and 1 patient, respectively. There was significant improvement in AP diameter (4.75 ± 1.75 mm to 10.33 ± 2.11 mm), interfacet distance (12.70 ± 4.86 mm to 18.92 ± 3.53 mm), and canal surface area (76.45 ± 25.36 mm2 to 187.13 ± 41.04 mm2) after decompression. Significant improvement was noted in mean height and angle of lateral recess after surgery of both sides suggesting that effective decompression of the bilateral canal was possible using a unilateral approach. Most of the patients (90%) showed excellent and good improvement after surgery. Postoperative canal surface area and AP diameter in patients who did not have any pain after surgery or had pain requiring occasional medication was higher compared with patients who continued to complain of pain and required continuous pain medication. Conclusion Although the number of patients was small with a short follow-up, the endoscopic technique was effective in improving AP diameter, interfacet distance, canal surface area, lateral recess height, and lateral recess angle, suggesting that an endoscopic technique using a unilateral approach is effective in bilateral decompression of neural elements.

Micro computed tomography evaluation of the Self-adjusting file and ProTaper Universal system on curved mandibular molars.

The aim of this investigation was to compare the cleaning and shaping efficiency of Self-adjusting file and Protaper, and to assess the correlation between root canal curvature and working time in mandibular molars using micro-computed tomography. Twenty extracted mandibular molars instrumented with Protaper and Self-adjusting file and the total working time was measured in mesial canals. The changes in canal volume, surface area and structure model index, transportation, uninstrumented area and the correlation between working-time and the curvature were analyzed. Although no statistically significant difference was observed between two systems in distal canals (p>0.05), a significantly higher amount of removed dentin volume and lower uninstrumented area were provided by Protaper in mesial canals (p<0.0001). A correlation between working-time and the canal-curvature was also observed in mesial canals for both groups (SAFr2 =0.792, p<0.0004, PTUr2=0.9098, p<0.0001).

Are Locked Facets a Contraindication for Extreme Lateral Interbody Fusion?

Extreme lateral interbody fusion (ELIF) has gained popularity as a minimally invasive treatment allowing for indirect decompression of neural elements. However, evidence regarding the influence of facet degeneration (FD) and facet tropism (FT) toward indirect decompression is lacking. The aim of the study was to evaluate whether indirect decompression is impaired by FD and FT in patients undergoing ELIF. Thirty-seven patients undergoing ELIF were included in a retrospective study. Radiographic parameters including disk height, segmental disk angle, foraminal area, FD, FT, and clinical outcome parameters (Oswestry Disability Index and Visual Analog Scale) were measured preoperatively and postoperatively. FD and FT were correlated with radiographic and clinical outcome parameters in order to determine predictors restricting indirect decompression. Thirty-seven patients with a total of 74 levels were analyzed. Clinical and radiographic outcome measures including central canal area (Δ=+17.2 mm2), mean disk height (Δ=+3 mm), and foraminal area (Δ=+9.9 mm2) revealed significant improvement compared with before surgery (P ≤ 0.05). Patients with severe FD (grade 4) were more likely to have FT ≥ 12 degrees (32.3%) than patients without/mild (grades 0 and 1; 10%) or moderate FD (grades 2 and 3; 13%), P ≤ 0.05. FD and FT did not affect disk height restoration, foraminal area, canal surface area, or clinical outcome measures (P ≥ 0.05). Indirect decompression of neural elements in ELIF is not impaired by FD and FT are not relative contraindications in patients undergoing ELIF.