Objectives: To compare the formation of dentinal defects using stainless-steel hand K-files (HFs)... more Objectives: To compare the formation of dentinal defects using stainless-steel hand K-files (HFs), rotary files, reciprocating files, and Self-Adjusting File (SAF), when used for oval root canals. Materials and Methods: One hundred and forty extracted human mandibular premolar with single root and oval canal were selected for this study. Oval canals were confirmed by exposing to mesio-distal and bucco-lingual radiographs. Teeth with open apices or anatomic irregularities were excluded. All selected teeth were de-coronated perpendicular to the long axis of the tooth, leaving roots segments approximately of 16 mm in length. Twenty teeth were left unprepared (control), and the remaining 120 teeth were divided into 6 groups (n = 20) and instrumented using HF (size 40/0.02), Revo-S (RS; size 40/0.06), ProTaper NEXT (PTN; size 40/0.06), WaveOne (WO; size 40/0.09), RECIPROC (RC; size 40/0.06), and the SAF (2 mm). Roots were then sectioned 3, 6, and 9 mm from the apex, and observed under stereomicroscope, for presence of dentinal defects. "No defect" was defined as root dentin that presented with no visible microcracks or fractures. "Defect" was defined by microcracks or fractures in the root dentin. Results: The control, HF, and SAF did not exhibit any dentinal defects. In roots instrumented by RS, PTN, WO, and RC files exhibited microcracks (incomplete or complete) in 40%, 30%, 55%, and 50%, respectively. Conclusions: The motor-driven root canal instrumentation with rotary and reciprocating files may create microcracks in radicular dentine, whereas the stainless-steel hand file instrumentation, and the SAF produce minimal or less cracks.
Can size 20, .04 taper rotary files reproducibly create a glide path for the self-adjusting file? Anex vivostudy in MB canals of mandibular molars
International Endodontic Journal, Apr 1, 2015
To test and compare the effectiveness and safety of two size 20, .04 taper rotary files that were... more To test and compare the effectiveness and safety of two size 20, .04 taper rotary files that were used to create a glide path for the self-adjusting file (SAF) in curved canals of mandibular molars. Forty mandibular molars with curved mesial roots and narrow MB root canals were selected based on a passage of size 15 K-files to WL; size 20 K-files could not reach WL. Only roots with no visible microcracks were included. Two types of size 20 rotary files were used for glide path preparation, the new Pre-SAF size 20, .04 taper file and the ProFile size 20, .04 taper, which served as the reference and control. Both files were used with 3-4 pecking strokes, which brought them to WL. Two parameters were tested whether the glide path allowed manual insertion of a 1.5-mm SAF file to WL and whether the procedure caused microcracks in the root dentine. Paired t-tests were used to compare the groups. Glide path preparation with both files allowed the manual insertion of the SAF file to WL in all 20 root canals, with no difference between the two groups. No cracks were detected after the procedure in any of the roots in either group. Both types of size 20, .04 taper rotary files were effective for glide path preparation for the SAF file in curved canals. Neither file type caused microcracks in root dentine.
Assessment of the fracture resistance of teeth instrumented using 2 rotary and 2 reciprocating files versus the Self-Adjusting File (SAF): An ex vivo comparative study on mandibular premolars
Journal of Conservative Dentistry, 2016
Current ex vivo study compared fracture resistance of teeth instrumented using 5 endodontic files... more Current ex vivo study compared fracture resistance of teeth instrumented using 5 endodontic files, filled with Gutta-percha and AH Plus. Sixty freshly extracted, single-rooted mandibular premolars were acquired and decoronated to obtain 15 mm segments. These samples were randomly divided into six groups (n = 10). Group 1 served as the control containing untreated samples (without instrumentation or filling). In Groups 2-6, samples were instrumented using rotary (Universal ProTaper and Revo-S), reciprocating (WaveOne and RECIPROC(®)), and self-adjusting file (SAF), respectively. Following instrumentation, the samples were filled by lateral compaction with Gutta-percha and AH Plus. A week later, after the sealer was completely set, a vertical load was applied to the specimen's canal in each group until fracture. The loads required for fracture were recorded, and statistical analysis was performed. The mean fracture load differed significantly among the groups (P < 0.01; one-way ANOVA). Tukey's post-hoc tests revealed that the fracture resistance was similar in the control and SAF groups (P > 0.05) and was significantly higher than that of the 2 rotary and reciprocating groups (P < 0.01). The samples instrumented by the SAF exhibited a better fracture resistance.
Incidence of microcracks in maxillary first premolars after instrumentation with three different mechanized file systems: a comparative ex vivo study
Clinical Oral Investigations, Mar 30, 2016
ObjectivesThe objective of this study is to determine the potential for microcracks in the radicu... more ObjectivesThe objective of this study is to determine the potential for microcracks in the radicular dentin of first maxillary premolars using three different mechanized endodontic instrumentation systems.MethodsEighty extracted maxillary first premolars with two root canals and no externally visible microcracks were selected. Root canal instrumentation was performed with either the ProTaper file system, the WaveOne primary file, or the self-adjusting file (SAF). Teeth with intact roots served as controls. The roots were cut into segments and examined with an intensive, small-diameter light source that was applied diagonally to the entire periphery of the root slice under ×20 magnification; the presence of microcracks and fractures was recorded. Pearson’s chi-square method was used for statistical analysis, and significance was set at p < 0.05.ResultsMicrocracks were present in 30 and 20 % of roots treated with the ProTaper and WaveOne systems, respectively, while no microcracks were present in the roots treated with the SAF (p = 0.008 and p = 0.035, respectively). Intact teeth presented with cracks in 5 % of the roots. The intensive, small-diameter light source revealed microcracks that could not be detected when using the microscope’s light alone.ConclusionsWithin the limitations of this study, it could be concluded that mechanized root canal instrumentation with the ProTaper and WaveOne systems in maxillary first premolars causes microcracks in the radicular dentin, while the use of the SAF file causes no such microcracks.Clinical relevanceRotary and reciprocating files with large tapers may cause microcracks in the radicular dentin of maxillary first premolars. Less aggressive methods should be considered for these teeth.
Lewinstein I, Zenziper E, Block J, Kfir A. Incorporation of chlorhexidine diacetate in provisiona... more Lewinstein I, Zenziper E, Block J, Kfir A. Incorporation of chlorhexidine diacetate in provisional cements: antimicrobial activity against Streptococcus mutans and the effect on tensile strength
Effect of glide path preparation on apical extrusion of debris in root canals instrumented with three single-file systems: An ex vivo comparative study
Journal of Conservative Dentistry, 2017
Aim: The aim of this study was to test the effect of new protocol of glide path preparation by 20... more Aim: The aim of this study was to test the effect of new protocol of glide path preparation by 20/0.04 rotary file on apical extrusion of debris when instrumenting fine curved mesial canals in mandibular molars with Self-adjusting File (SAF) and compare it to a glide path prepared by 20/0.02 hand K-file and rotary OneShape (OS) and reciprocating WaveOne (WO) file instrumentation. Materials and Methods: Sixty mandibular molars with curved mesial roots were selected and randomly divided into three groups (n = 20) for instrumentation. In two groups, glide path was prepared using 20/0.02 K-file for instrumentation by OS (size 25/0.06 taper) and WO (size 25/0.08 taper) files; in the remaining group, 20/0.04 rotary file was used for glide path preparation and instrumented by SAF (1.5 mm). The debris extruded during instrumentation was collected in preweighed Eppendorf tubes and stored in an incubator at 70°C for 5 days. Tubes containing the dry extruded debris were then weighed. One-way analysis of variance (ANOVA) was applied to the weights obtained, followed by Tukey's post hoc test for multiple comparison. Results: The mean debris (g) extruded apically was 0.000651 ± 0.000291, 0.000823 ± 0.000319, and 0.000473 ± 0.000238 for Group 1 (20/0.02 + OS), Group 2 (20/0.02 + WO), and Group 3 (20/0.04 + SAF), respectively. The groups exhibited a significant difference (P < 0.01; ANOVA). Group 3 resulted in least debris extrusion compared to Groups 1 and 2 (P < 0.01; Tukey's post hoc test). Conclusion: Glide path prepared to size 20/0.04 and SAF 1.5 mm instrumentation produce less debris in curved mesial canals of mandibular molars, compared to glide path established by 20/0.02 and instrumentation by OS and WO files.
Continuous Instrumentation and Irrigation: The Self-Adjusting File (SAF) System
Springer eBooks, 2015
The recently introduced self-adjusting file (SAF) system is the first of its kind, performing con... more The recently introduced self-adjusting file (SAF) system is the first of its kind, performing continuous and simultaneous instrumentation and irrigation. As an instrumentation device it adapts itself to the shape of the canal, including its cross section, as opposed to most rotary file systems that machine the canal to the shape of the file. The SAF system removes a uniform dentin layer from all around the canal as opposed to rotary files which are using excessive removal of sound dentin in attempt to include the whole canal within the preparation. Combined with its effective irrigation, it allows a new concept of minimally invasive endodontics. The SAF system is a no-pressure irrigation system combined with an added mechanical scrubbing effect. The effective cleaning of oval canals enables more effective disinfection and better obturation than can be achieved with rotary files. Its scrubbing effect is also useful in the final stage of retreatment as well as in the treatment of root canals of immature teeth.
Healing after surgical retreatment at four time points: A retrospective study
International Endodontic Journal, Nov 5, 2021
AimTo evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 ... more AimTo evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 months post‐operatively, and to search for prognostic factors that may affect the outcome.MethodologyClinical records and intraoral periapical radiographs were collected from patients who had undergone surgical retreatment between 2009 and 2015 and attended 6‐, 12‐, 24‐ and 48‐month follow‐up visits. Surgical retreatment was performed by one endodontist and involved minimal root‐end resection and maximal length root‐end preparation using prebent ultrasonic files. Outcomes were categorized as complete, incomplete, uncertain or unsatisfactory healing, based on clinical and radiographic findings. The complete and incomplete categories were pooled and considered successes, while uncertain and unsatisfactory outcomes were considered failures. Changes in healing outcome were analysed using the McNemar‐Bowker test, and prognostic factors were analysed using univariate analysis.ResultsThe study cohort included 297 patients with 384 teeth. The overall success rate after 48 months was 90.6% compared with 88.5%, 93% and 92.4% after 6, 12 and 24 months respectively. Age, gender, presence of isthmus and length of canal preparation had no significant influence on the outcome. Lesion size and tooth type had a significant influence only after 6 and 12 months, respectively, with no significant differences at other time points. Fifty per cent of the teeth classified as unsatisfactory or uncertain healing at the 6 months follow‐up improved to incomplete or complete healing after 12 months. None of the cases classified as unsatisfactory healing after 12 months subsequently improved, and only 2 cases that were classified as uncertain healing after 12 months improved after 24 months.ConclusionsSurgical retreatment was found to be a predictable procedure with a high success rate of 90.6% after 4 years. Over the follow‐up periods, only a minor regression in the success rate was found. The 12 months follow‐up results closely indicated the long‐term outcome of surgical retreatment.
Antibacterial activity and tensile strength of provisional cements modified with fluoridecontaining varnish
Quintessence International, Feb 1, 2013
To test three noneugenol provisional cements (TempBond NE, RelyX Temp NE, and Freegenol) for thei... more To test three noneugenol provisional cements (TempBond NE, RelyX Temp NE, and Freegenol) for their antibacterial properties and to test the hypothesis that addition of fluoride varnish confers antibacterial properties on these provisional cements without compromising their tensile strength. A total of 576 cylindrical samples were prepared (96 of each of six types) from three noneugenol provisional cements, both unmodified and modified by the addition of 5% w/w Duraphat fluoride varnish. The samples were aged in saline that was replaced twice a week for up to 90 days. Twenty-four samples of each type were removed from the saline at 1, 7, 30, or 90 days and assessed for antibacterial properties against Streptococcus mutans by using an agar diffusion test (n = 12) and tensile strength by using a diametral tensile strength test (n = 12). Data were subjected to one- and three-way ANOVA, the Tukey honestly significant difference test, and t test at a significance level of .002 (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .002). TempBond NE had no antibacterial activity in its unmodified form but showed antibacterial activity when modified by the addition of 5% w/w fluoride varnish. Freegenol had the highest antibacterial activity in its unmodified form, which was not altered by the addition of the varnish. RelyX Temp NE had mild antibacterial activity that was slightly enhanced by adding the varnish. Adding the varnish reduced the tensile strength of TempBond NE and Freegenol, but did not affect the tensile strength of RelyX Temp NE. Antibacterial activity was observed for the unmodified form of Freegenol and TempBond NE after the addition of the fluoride varnish. The addition of the fluoride varnish reduced the tensile strength of both TempBond NE and Freegenol.
Apical extrusion of debris during the preparation of oval root canals: a comparative study between a full-sequence SAF system and a rotary file system supplemented by XP-endo finisher file
Clinical Oral Investigations, Jun 12, 2017
ObjectivesThe purpose of this study was to assess the amount of apically extruded debris during t... more ObjectivesThe purpose of this study was to assess the amount of apically extruded debris during the preparation of oval canals with either a rotary file system supplemented by the XP-endo Finisher file or a full-sequence self-adjusting file (SAF) system.Materials and methodsSixty mandibular incisors were randomly assigned to two groups: group A: stage 1—glide path preparation with Pre-SAF instruments. Stage 2—cleaning and shaping with SAF. Group B: stage 1—glide path preparation with ProGlider file. Stage 2—cleaning and shaping with ProTaper Next system. Stage 3—Final cleaning with XP-endo Finisher file. The debris extruded during each of the stages was collected, and the debris weights were compared between the groups and between the stages within the groups using t tests with a significance level set at P < 0.05.ResultsThe complete procedure for group B resulted in significantly more extruded debris compared to group A. There was no significant difference between the stages in group A, while there was a significant difference between stage 2 and stages 1 and 3 in group B, but no significant difference between stages 1 and 3.ConclusionsBoth instrumentation protocols resulted in extruded debris. Rotary file followed by XP-endo Finisher file extruded significantly more debris than a full-sequence SAF system. Each stage, in either procedure, had its own contribution to the extrusion of debris.Clinical relevanceFinal preparation with XP-endo Finisher file contributes to the total amount of extruded debris, but the clinical relevance of the relative difference in the amount of apically extruded debris remains unclear.
The purpose of this study was to compare the effectiveness of self-adjusting file (SAF), XP-endo ... more The purpose of this study was to compare the effectiveness of self-adjusting file (SAF), XP-endo finisher (XP), passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of Ca(OH) 2 from an artificial groove. Eighty mandibular incisors with single oval canals were prepared to size 40/0.04 and split longitudinally. A standardised groove was prepared in the apical third and filled with Ca(OH) 2. The root halves were reassembled and divided into two control groups (n = 4) and four experimental groups (n = 18) according to the removal methods used. The amount of residual Ca(OH) 2 was evaluated using a four-grade scoring system. The differences among the groups were analysed using the Kruskal-Wallis test (P < 0.05). SAF, XP and PUI removed significantly more Ca(OH) 2 than SNI (P < 0.001), although there were no significant differences among them (P = 0.209). None of the tested methods could completely clean Ca(OH) 2 from the groove.
Aim To compare the efficacy of the XP-endo finisher file (XP) (FKG Dentaire, La Chaux de Fonds, S... more Aim To compare the efficacy of the XP-endo finisher file (XP) (FKG Dentaire, La Chaux de Fonds, Switzerland) to that of passive ultrasonic irrigation (PUI) and conventional syringe and needle irrigation (SNI) in the removal of calcium hydroxide paste from an artificial standardized groove in the apical third of root canals. Methodology The root canals of 68 mandibular incisors with single oval canals were prepared using Mtwo instruments (VDW GmbH, Munich, Germany) up to size 40, .04 taper. Each tooth was split longitudinally, and in one half of the root, a standardized groove was prepared in the apical part of the specimen. The grooves were filled with Ca(OH) 2 , and the root halves were reassembled. The roots were randomly divided into two control groups (n = 4) and three experimental groups (n = 20) according to the Ca(OH) 2 methods used: XP, PUI and SNI. The amount of remaining medicament was evaluated under X25 magnification using a 4-grade scoring system. Kappa values were calculated for intra-and interobserver agreement evaluation. The differences in the Ca(OH) 2 scores amongst the different groups were analysed using the Kruskal-Wallis test. Results None of the tested methods could completely clean the Ca(OH) 2 from the artificial standardized groove in the apical third of the root canals. XP and PUI removed significantly more Ca(OH) 2 than SNI (P < 0.001), with no significant differences between them (P = 0.238). Conclusions XP and PUI were more effective in removing Ca(OH) 2 from artificial standardized grooves in the apical third of root canals than SNI.
[Vertical root fractures in endodontically treated teeth--Part II: Etiology and prevention]
PubMed, Apr 1, 2006
The etiologic factors for vertical fractures in endodontically treated teeth are predisposing fac... more The etiologic factors for vertical fractures in endodontically treated teeth are predisposing factors, such as loss of tooth material, anatomy of the susceptible teeth, moisture loss, previous dentinal cracks, and loss of bone support; and iatrogenic factors, such as excessive removal of radicular dentin as a result of endodontic and prosthetic procedures and improper selection of dowels. Identification of susceptible teeth and roots, proper selection and cementation of dowels, and avoidance of excessive force during condensation of gutta percha and in removal of tooth structure during endodontic and prosthetic procedures, are all measures that can be taken to prevent root fractures.
Anda Kfir, DMD, Senior Lecturer and Chair, Department of Endodontology, The Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel
Aim To test the effect of low-dose doxycycline on bone resorption associated with apical periodon... more Aim To test the effect of low-dose doxycycline on bone resorption associated with apical periodontitis. Methodology Apical periodontitis was induced by occlusal pulp exposure in the mandibular first molars of 36 rats. Animals were divided into three groups of 12: group A received doxycycline in drinking water at a dose of 5.85 mg day)1 ; group B received a dose of 1.48 mg day)1 (one-quarter of the original dose); and group C received no medicament and served as the control. A bioassay determined the doxycycline serum levels. After 21 days, the mandibles were removed, radiographed and the radiographs scanned to generate digital images. These images were analysed morphometrically and the total area of the periapical bone resorption of the mesial and distal roots of each tooth was determined and used to compare the groups. Statistical analysis was completed using anova with repeated measures. Results The mean doxycycline serum level in group A was 0.22(±0.03) lg mL)1 and in group B below the detection level of the assay (<0.062 lg mL)1). The mean area of the periapical bone resorption in the control group C was 2.91(±0.61) mm 2. In animals treated with a low-dose doxycycline, the mean size of the bone resorption was significantly smaller at 1.59(±0.59) mm 2 (group A) and 1.72(±0.85) mm 2 (group B) (P ¼ 0.001). No significant difference was found in the area of the bone resorption between these two groups A and B. Conclusions Low-dose doxycycline reduced the area of bone resorption associated with apical periodontitis in the mandibular first molar teeth of rats.
Healing after surgical retreatment at four time points: A retrospective study
International Endodontic Journal, 2021
AimTo evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 ... more AimTo evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 months post‐operatively, and to search for prognostic factors that may affect the outcome.MethodologyClinical records and intraoral periapical radiographs were collected from patients who had undergone surgical retreatment between 2009 and 2015 and attended 6‐, 12‐, 24‐ and 48‐month follow‐up visits. Surgical retreatment was performed by one endodontist and involved minimal root‐end resection and maximal length root‐end preparation using prebent ultrasonic files. Outcomes were categorized as complete, incomplete, uncertain or unsatisfactory healing, based on clinical and radiographic findings. The complete and incomplete categories were pooled and considered successes, while uncertain and unsatisfactory outcomes were considered failures. Changes in healing outcome were analysed using the McNemar‐Bowker test, and prognostic factors were analysed using univariate analysis.ResultsThe study ...
Effect of glide path preparation on apical extrusion of debris in root canals instrumented with three single-file systems: An ex vivo comparative study
Journal of Conservative Dentistry, 2017
Aim: The aim of this study was to test the effect of new protocol of glide path preparation by 20... more Aim: The aim of this study was to test the effect of new protocol of glide path preparation by 20/0.04 rotary file on apical extrusion of debris when instrumenting fine curved mesial canals in mandibular molars with Self-adjusting File (SAF) and compare it to a glide path prepared by 20/0.02 hand K-file and rotary OneShape (OS) and reciprocating WaveOne (WO) file instrumentation. Materials and Methods: Sixty mandibular molars with curved mesial roots were selected and randomly divided into three groups (n = 20) for instrumentation. In two groups, glide path was prepared using 20/0.02 K-file for instrumentation by OS (size 25/0.06 taper) and WO (size 25/0.08 taper) files; in the remaining group, 20/0.04 rotary file was used for glide path preparation and instrumented by SAF (1.5 mm). The debris extruded during instrumentation was collected in preweighed Eppendorf tubes and stored in an incubator at 70°C for 5 days. Tubes containing the dry extruded debris were then weighed. One-way analysis of variance (ANOVA) was applied to the weights obtained, followed by Tukey's post hoc test for multiple comparison. Results: The mean debris (g) extruded apically was 0.000651 ± 0.000291, 0.000823 ± 0.000319, and 0.000473 ± 0.000238 for Group 1 (20/0.02 + OS), Group 2 (20/0.02 + WO), and Group 3 (20/0.04 + SAF), respectively. The groups exhibited a significant difference (P < 0.01; ANOVA). Group 3 resulted in least debris extrusion compared to Groups 1 and 2 (P < 0.01; Tukey's post hoc test). Conclusion: Glide path prepared to size 20/0.04 and SAF 1.5 mm instrumentation produce less debris in curved mesial canals of mandibular molars, compared to glide path established by 20/0.02 and instrumentation by OS and WO files.
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