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This clinical study evaluated the antibacterial effects of calcium hydroxide associated with different vehicles during the treatment of infected teeth with apical periodontitis.Bacteriologic samples were taken from 90 necrotic root canals of teeth with apical periodontitis before (S1) and after preparation with a rotary nickel-titanium instrument system and 2.5% sodium hypochlorite irrigation (S2). The teeth were distributed in 3 groups according to the intracanal medication used, which consisted of a calcium hydroxide paste in glycerin, camphorated paramonochlorophenol/glycerin (CHPG), or 2% chlorhexidine for 1 week, and then another sample was taken (S3). The frequency of bacteria-positive cases and the reduction of bacterial counts were evaluated by quantitative real-time polymerase chain reaction.Substantial intracanal bacterial reduction was observed after preparation in the 3 groups (P .001). After calcium hydroxide paste in glycerin medication, the number of bacteria-positive cases decreased from 20/29 (69%) to 17/29 (59%); however, the mean bacterial counts increased 8.4% from S2 to S3. Medication with CHPG reduced the number of bacteria-positive cases from 17/29 (59%) to 15/29 (52%), with a significant mean S2-S3 reduction of 71% (P .05). In the chlorhexidine group, the number of bacteria-positive cases decreased from 21/30 (70%) to 17/30 (57%) after medication, with a mean S2-S3 reduction of 55%, which, however, was not statistically significant (P .05). Intergroup comparisons showed no significant differences (P .05).Comparison between the 3 calcium hydroxide pastes showed no significant differences in antibacterial effectiveness in the main root canal. However, only the CHPG paste showed a significant reduction in bacterial counts when postpreparation and postmedication samples were compared.

Objective: To assess the centralization and dentin thickness of mesial root canals by microcomputed tomography (micro-CT). Methods: Ninety-nine mandibular molars Vertucci’s type IV mesial canals were scanned by micro-CT. The mesiodistal deviation; and the centroid were calculated for mesiobuccal (MB) and mesiolingual (ML) canals (apical 4 mm and full canal). Results: The centroid was deviated in MB and ML canals in full canal (MB=0.83 mm, 0.02-2.30 mm, and ML=0.83 mm, 0.05-3.99 mm), and in 4mm (MB=0.18mm,0.01-1.01 mm and ML=0.21 mm, 0.01-1.01 mm). In the full canal, both MV (69%) e ML (57%) deviated to mesial (M). In 4 mm, the deviation was M in 51% for MB canals and 52% of ML to distal (D). The dentin thickness was similar for MB and ML canals and their walls. Distal wall was lower for MB canal (0.07 mm) and M wall the higher in the MB canal (2.46 mm). Conclusions: There is no centrality of mesial canals in mandibular first molars. The M deviation was frequent in the full canal. Dentin thickness were similar between mesial canals.

Objectives The oval canals may be associated with inadequate debridement, which can affect the quality of the root canal filling, thus the treatment outcome. The aim of the present work was to compare the quality of oval canals fillings using EndoSequence BC sealer with the single-cone technique or cold lateral compaction. Materials and Methods Thirty-eight human single-rooted premolars with oval canals were instrumented to 1 mm from the apical foramen with hand nickel–titanium files, followed by circumferential filing with Hedstrom files. Teeth were paired into two groups based on their micro-computed tomography (CT) morphological parameters. Both groups were filled using EndoSequence BC sealer. The first used a single cone and the other with the cold lateral compaction technique. The voids volume was evaluated by micro-CT and the percentage was calculated for the total length and for the apical 5 mm of each canal. The Mann–Whitney U test was used to assess whether the surface area and obturation length differed significantly between the groups and to compare the percentage of voids for each technique. Results Both techniques resulted in less than 16% voids, with no statistically significant difference between them for the total canal length and for the apical 5 mm (p > 0.05). Conclusions The quality of the obturation performed with the single-cone technique was similar to that achieved with lateral compaction using EndoSequence BC sealer in oval canals.

This study assessed the apical transportation using Mani GPR or HyFlex NT during the retreatment of curved root canals. Thirty-eight roots were analysed using micro-CT for the comparison of apical transportation produced by two retreatment systems. Longitudinal transportation, horizontal transportation, variation in the canal angle of curvature and variation in the canal/root width ratio were analysed. Longitudinal transportation was frequently observed, regardless of the system used. The canals retreated with Mani GPR showed a significantly higher horizontal transportation at 1 mm from the root apex (P 0.01) and greater variation of the canal curvature angle (P 0.01). The canal/root width ratio was similar between groups (P 0.05). In conclusion, longitudinal transportation occurred more frequently in the mesial canal walls. Mani GPR showed greater horizontal transportation at 1 mm short of the apex, and higher variation of the canal curvature angle compared with HyFlex NT.

Introduction This study evaluated the association of different variables that may influence the outcome of root canal treatment through cone-beam computed tomographic (CBCT) and micro–computed tomography (micro-CT) assessments of root apexes obtained by endodontic microsurgery of teeth with posttreatment apical periodontitis (AP), the agreement between CBCT and micro-CT findings, and the association of these variables with symptoms or lesion size. Methods Clinical and CBCT records and root apexes obtained by endodontic microsurgery from 11 cases of symptomatic AP and 22 cases of asymptomatic AP were available. Apical root specimens were further scanned using micro-CT imaging. CBCT parameters included periapical radiolucency size, apical extent/density of root canal filling, and occurrence of procedural errors. Micro-CT images evaluated the same parameters plus the presence of filling material in lateral canals and ramifications, the volume of the filled/nonfilled apical root canal, and the percentage of the nonfilled canal space. The agreement between CBCT/micro-CT observations was evaluated. Results Mandibular teeth, a lesion size Conclusions Tooth location, lesion size, the nonfilled apical canal volume, and the percentage of the nonfilled apical canal volume were associated with symptomatic AP. In addition, lesion size was significantly associated with tooth location and apical root canal filling density. CBCT imaging may not provide a reliable evaluation of procedural errors associated with posttreatment disease.

Introduction This study assessed the cleaning, shaping, and disinfection abilities of 2 instrumentation systems in molar root canals using a novel correlative analytical approach. Methods The root canals from extracted mandibular and maxillary molars with apical periodontitis were pair matched according to anatomic similarities as determined by micro–computed tomographic analysis and prepared with either XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n = 16) or Reciproc Blue (VDW, Munich, Germany) (n = 16) instruments and 2.5% sodium hypochlorite irrigation. Pre- and postpreparation micro–computed tomographic scans were used to identify and calculate the unprepared surface areas (shaping), which were histobacteriologically evaluated for the presence of residual bacteria (disinfection) and pulp tissue remnants (cleaning) in each canal third. Results Unprepared canal surface areas for XP-endo Shaper and Reciproc Blue in the full canal length were approximately 26% and 19% (P .05). Preparation with Reciproc Blue resulted in 37.5% canals free of bacteria in all sections examined and 56% in the apical sections only. XP-endo Shaper resulted in 44% canals free of bacteria in all sections, and 56% in the apical part of the canal only. Pulp tissue remnants were not observed in 31% (all canal sections) and 50% (apical canal sections) of specimens from both instrument systems. No significant differences were observed between instruments when comparing the amount of pulp tissue remnants and the number of cases negative for bacteria and tissue remnants (P > .05). Conclusions Although the Reciproc Blue instrument had superior shaping ability in comparison with XP-endo Shaper, both systems performed similarly in cleaning and disinfecting root canals. Irregular canals and difficult-to-reach areas were not thoroughly cleaned and disinfected by any of the tested systems.

The impact of minimally invasive endodontic procedures on root canal disinfection has not been determined. This ex vivo study compared root canal disinfection and shaping in teeth with contracted or conventional endodontic cavities.Mandibular incisors with oval-shaped canals were selected and anatomically matched based on micro-computed tomographic (micro-CT) analysis and distributed into 2 groups. Conservative and conventional access cavities were prepared, and the canals were contaminated with a pure culture of Enterococcus faecalis for 30 days. Root canal preparation in both groups was performed using the XP-endo Shaper instrument (FKG Dentaire, La Chaux-de-Fonds, Switzerland) and 2.5% sodium hypochlorite irrigation. Intracanal bacteriologic samples were taken before and after preparation, and DNA was extracted and subjected to quantitative polymerase chain reaction. Micro-CT scans taken before and after preparation were used for shaping evaluation. Bacteriologic data were analyzed by the Poisson regression model and the chi-square test with Yates correction. Micro-CT data were analyzed by the Wilcoxon, Mann-Whitney, and Student t tests with the significance level set at 5%.All initial samples were positive for E. faecalis. After preparation, the number of bacteria-positive samples was significantly higher in the contracted cavity group (25/29, 86%) than in the conventional cavity group (14/28, 50%) (P.01). Intergroup quantitative comparison showed that the reduction in bacterial counts was also significantly higher in the group of conventional cavities (P.01). Micro-CT data revealed no significant difference in the amount of unprepared areas between groups.Our findings showed that although shaping using an adjustable instrument was similar between groups, disinfection was significantly compromised after root canal preparation of teeth with contracted endodontic cavities.

To evaluate the effectiveness of a solvent (eucalyptol) in improving filling material removal from canals connected by isthmuses, and the additional cleaning effect of a finishing instrument.The mesial canals from 32 mandibular molars (Vertucci's type II morphology) were instrumented and filled with the single-cone technique using Reciproc R25 gutta-percha points (VDW, Munich, Germany) combined with Sealer 26 (Dentsply, Petrópolis, RJ, Brazil). Each root was then subjected to retreatment using the Mtwo instrument system (VDW), with or without a solvent (n = 16 per group). The volume of filling material in the canals was assessed by micro-computed tomographic (micro-CT) scans taken before and after retreatment. Canals with remnants of filling material received a supplementary procedure with the XP-endo Finisher R instrument (FKG Dentaire, La Chaux-de-Fonds, Switzerland), with or without eucalyptol, and another micro-CT scan was taken. All retreatment procedures were performed inside a cabinet under a controlled temperature (37 °C). Filling material removal was evaluated in the 5-mm apical canal system for the canal+isthmus space or the isthmus alone. Statistical analyses were performed to compare the removal of filling material with and without eucalyptol, and after a supplementary approach with XP-endo Finisher R. The level of significance was set at 5% for all statistical tests (P 0.05).The amount of filling material removed from the canal+isthmus with Mtwo instruments was 83.2% when no solvent was used and 83.8% using the solvent (P 0.05). When the isthmus area was evaluated separately, most specimens were associated with a reduction in the filling material, with no significant difference between the groups with or without using a solvent (P 0.05). The supplementary step with XP-endo Finisher R significantly improved removal of filling material from both canal and isthmus area (P 0.05), regardless of the use of a solvent (P 0.05).The use of eucalyptol did not improve filling material removal from Vertucci's type II molar mesial canals and isthmuses. XP-endo Finisher R significantly enhanced removal of filling material from the canals and isthmuses.

AIM To compare the effects of three instrumentation systems, and a supplementary approach with a finishing instrument, on filling material removal during retreatment of mandibular molar canals. METHODS Sixty mesial canals from mandibular molars (Vertucci's type IV anatomy) were instrumented, filled and subjected to retreatment. After initial removal of the root canal filling material using the D-RaCe system, the canals were randomly distributed into three groups (n = 20) according to the instrument system used for preparation: the Self-Adjusting File (SAF), TRUShape or XP-endo Shaper. The filling material volume in the apical 5 mm of the canals was assessed by means of micro-computed tomography (micro-CT) before and after retreatment. All specimens with residual filling material were subjected to a supplementary approach with the XP-endo Finisher R instrument and another micro-CT scan was taken. Data on the volumes of filling material and incidence of total removal were compared between groups by the general linear model for paired data and the Fisher's exact test. The effects of the refinement step were evaluated by the Wilcoxon Signed Ranks test. RESULTS The amount of removed material was 92.4%, 96.9% and 96.9% for the SAF, TRUShape and XP-endo Shaper, respectively. There were no significant differences between them (P > 0.05). Canals were completely cleaned of filling material in 70% of the specimens for XP-endo Shaper, 55% for SAF and 30% for TRUShape; the difference between XP-endo Shaper and TRUShape was significant (P = 0.03). The supplementary step with the XP-endo Finisher R instrument was associated with additional filling material removal of 38% (P

The aim of the study was to evaluate the accuracy of microcomputed tomography (mCT) to detect dentinal cracks when compared with scanning electron microscopy (SEM) and operating microscopy (OM). Different conditions of pixel size (10 or 17 μm), sample moisture (dry/moist), and transillumination (with/without) were evaluated. Additionally, the influence of the dentinal defect width on its detection was analyzed. The root canals of human mandibular incisors were prepared with the Reciproc R40 instrument (VDW, Munich, Germany). The roots were sectioned 5 and 10 mm from the apex, and mCT scans of middle and apical segments were performed at two pixel sizes: 10 μm and 17 μm, under dry and moist conditions (groups: 10dry, 10moist, 17dry, and 17moist). The operating microscope was used with and without transillumination (groups: OMTrans and OM). Findings showed that accuracy was moderate for the 10dry, 10moist, and OMTrans groups, poor for OM and very poor for 17dry and 17moist. The thickness of the dentin crack significantly influenced its detection by mCT using the resolution of 10 μm in both dry and wet conditions ( P = .002 ), 17 μm in the dry condition ( P = .002 ), and by the operating microscope using transillumination ( P = .009 ). Some cracks visualized in SEM were not detected by mCT and an operating microscope. Not only the mCT resolution but also the sample moisture condition and the dentinal crack width can significantly influence its detection.

This clinical study reports on the antibacterial effects and outcome of endodontic treatment using either a single-file or a multifile system, associated with calcium hydroxide interappointment medication. The root canals of single-rooted teeth with apical periodontitis were treated by using either Reciproc or BioRaCe instrument systems, 2.5% NaOCl irrigation, and calcium hydroxide medication. Bacteriological samples taken before preparation and immediately before obturation were evaluated for total bacterial counts by quantitative real-time polymerase chain reaction (qPCR). Patients were followed up and the treatment outcome was assessed by clinical and radiographic criteria. Decreasing lesions were classified as success in a lenient criterion or failure in a rigid one. Bacteria were detected in all initial samples (47 cases) and were significantly reduced after treatment in both groups (p0.05). Quantitative bacterial reduction was similar between groups (p>0.05). The success rate in the BioRaCe group was 95.5% and 77% in the loose and rigid criterion, respectively. In the Reciproc group, corresponding figures were 88% and 76%. Differences in outcome were not significant (p>0.05). No diseased case showed negative qPCR results for bacteria. A difference of >1 Log10 counts was observed between healed and diseased cases. Root canal treatments of teeth with apical periodontitis using a single-file or a multifile system for preparation, associated with NaOCl irrigation and calcium hydroxide interappointment medication, showed similar antibacterial effectiveness and success rate.

This study compared the efficacy of XP-Endo Finisher R and R1-Clearsonic insert in removing filling material remnants from oval canals. Twelve pairs of contralateral premolars were treated and subsequently retreated with Reciproc 50. A supplementary procedure with XP-Endo Finisher R or R1-Clearsonic was performed. Micro-computed tomography was used to quantify the filling material volume in the full canal and apical segment lengths. Intragroup analyses revealed significant reduction of filling material after both procedures, not only in the full canal but also in the apical segment (P 0.05). The amount of filling material removed with XP-Endo Finisher R and R1-Clearsonic was 47.9% and 52.2% in the apical segment (P 0.05), and 82.1% and 64.6% in the full canal (P 0.05). None of the instruments was effective in completely removing the filling material from the apical canal, but better results were obtained with XP-Endo Finisher R in the total canal length.

Introduction This study compared the shaping ability of ProTaper Next (Dentsply Sirona, Tulsa, OK) and BT-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland) instrument systems in the mesial canals of mandibular molars using micro–computed tomographic (micro-CT) imaging. Methods A total of 17 type IV mesial roots of extracted first mandibular molars were scanned using micro-CT imaging before and after root canal preparation with the 2 instrument systems. Both systems were used in the same root but alternating the mesial canals from root to root. The following parameters were analyzed: root canal volume, surface area, unprepared surface areas, transportation, canal/root width ratio, and preparation time. Results There were no statistically significant differences between the 2 systems for all evaluated parameters (P > .05). The unprepared surface areas for the full canal length and the apical 5-mm segment were 33% and 14% for BT-RaCe and 31% and 14% for ProTaper Next, respectively. After preparation, all root canals had a diameter that was not larger than 35% of the root diameter at the coronal and middle segments. Conclusions The 2 systems showed no differences in any of the evaluated shaping parameters. None of the tested systems put the roots at risk of fracture because of excessive dentin removal.

Introduction This micro–computed tomographic study investigated the original anatomic diameters of the apical portion of mandibular molar mesial canals and matched them to the dimensions of instruments that are currently available and commonly used for apical preparation. Methods One hundred eight mandibular molar mesial roots with Vertucci type IV configuration were scanned by micro–computed tomographic imaging, and the largest anatomic diameter of both mesial canals at 1, 2, 3, and 4 mm short of the apical foramen was measured. Canal diameters were compared with the dimensions of 10 endodontic instruments for simulation of preparation 1 mm short of the apical foramen. Accordingly, the instruments with a diameter larger than the largest canal diameter were regarded as having the potential to prepare 100% of the canal walls at each specific point or over the 4-mm apical segment. Results At 1 and 2 mm short of the apical foramen, a 45/.02 instrument had a larger diameter than the mesiobuccal canal diameter in 73% and 55% of the teeth, respectively. Corresponding figures for the mesiolingual canal were 65% and 55%. When the entire 4-mm apical segment was considered, a 40/.06 instrument had better results, being larger than the apical canal in about 20% of the specimens. Overall, 78% of the apical canals would not be completely prepared by any instrument. Based on the mean (median) anatomic diameters, the adequate instrument dimensions would be 40/.10 (40/.08) for mesiobuccal canals and 45/.08 (40/.09) for mesiolingual canals. Conclusions The dimensions of the available instruments are not compatible with complete apical preparation in the majority of cases. The ideal instrument size/taper to include all the canal walls in apical preparation is too large and may not be safe for clinical use.

To evaluate and compare irrigant distribution throughout the root canal system of mesial roots of mandibular molars after application of distinct adjunctive irrigant activation procedures.Fifteen extracted mandibular molars presenting Fan's type II, III, or IV isthmus configurations were selected. The canals were initially enlarged and cleaned. The same specimens were subjected to conventional positive pressure irrigation (PPI) followed by adjunctive irrigation approaches: passive ultrasonic irrigation (PUI), mechanical activation with the XP-endo Finisher instrument, and a control group in which the irrigant remained in the canal with no activation. Retention time for the irrigant was the same for all groups. Sodium hypochlorite mixed with a contrast medium (Omnipaque 300) was used as the irrigant. Before and immediately after the adjunctive irrigation, micro-computed tomographic (micro-CT) scans were taken to evaluate the volume of the entire root canal system that was filled by the irrigant. An exclusive analysis was also done for the isthmus area.Analysis of the entire root canal system showed that the XP-endo Finisher instrument promoted better distribution of the irrigant than PUI and the control group (p 0.01). PUI was not significantly different from the control group (p 0.05). A separate analysis of the isthmus area showed no significant difference between the adjunctive irrigation methods and the control (p 0.05).The XP-endo Finisher instrument promoted better distribution of irrigant throughout the root canal system, especially in the apical canal segment, when compared to PUI. However, the tested approaches did not differ as to the ability to drive irrigants into the isthmus area.This study highlighted that the XP-endo Finisher instrument presented a better performance to distribute irrigant throughout the root canal system, especially in the apical canal segment compared to positive pressure irrigation and PUI.

Introduction This study evaluated the bacterial and human metaproteome of root apexes and the matched inflammatory lesions from teeth with post-treatment apical periodontitis. Methods Root apexes and matched inflammatory lesions from root canal–treated teeth with apical periodontitis were obtained during periradicular surgery. All root canal fillings were rated as adequate on the basis of radiographs and cone-beam computed tomography. The specimens were cryopulverized and subjected to metaproteomic analysis for human and bacterial proteins by using a mass spectrometry platform that is based on nanoflow liquid chromatography coupled with linear ion trap quadrupole Velos Orbitrap. Results The metaproteome analyses revealed the presence of viable and metabolically active human and bacterial cells in both apexes and lesions. Several bacterial proteins of interest for pathogenicity and therapeutics were identified in both apexes and lesions, including proteins related to antibiotic resistance, proteolytic function, stress response, adhesion, and virulence. Many human proteins related to immune defense mechanisms were also detected in both root apex and lesion specimens, including immunoglobulins, complement system, and proteins linked to T-cell and B-cell activation, neutrophil microbicidal processes, antigen recognition/presentation, bone resorption, and protection against tissue damage. Conclusions Occurrence of host defense factors from the innate and adaptive immune responses and bacterial virulence, survival, and resistance proteins in matched root apexes/periradicular inflammatory lesions indicates a complex and dynamic host-pathogen interaction in teeth with post-treatment apical periodontitis.

Introduction A thorough knowledge of root canal anatomy is critical for successful root canal treatments. This study evaluated the internal anatomy of the palatal roots of maxillary first molars with micro–computed tomography (microCT). Methods The palatal roots of extracted maxillary first molars ( n = 169) were scanned with microCT to determine several anatomic parameters, including main canal classification, lateral canal occurrence and location, degree of curvature, main foramen position, apical constriction presence, diameters 1 and 2 mm from the apex and 1 mm from the foramen, minor dentin thickness in those regions, canal volume, surface area, and convexity. Results All canals were classified as Vertucci type I. The cross sections were oval in 61% of the canals. Lateral canals were found in 25% of the samples. The main foramen did not coincide with the root apex in 95% of the cases. Only 8% of the canals were classified as straight. Apical constriction was identified in 38% of the roots. The minor and major canal diameters and minor dentin thickness were decreased near the apex. The minor dentin thickness 1 mm from the foramen was 0.82 mm. The palatal canals exhibited a volume of 6.91 mm 3 and surface area of 55.31 mm 2 and were rod-shaped. Conclusions The root canals of the palatal roots were classified as type I. However, some factors need to be considered during the treatment of these roots, including the frequent ocurrence of moderate/severe curvatures, oval-shaped cross-sections, and lateral canals, noncoincidence of the apical foramen with the root apex, and absence of apical constriction in most cases.

Introduction This in vivo study compared the antibacterial effectiveness of a reciprocating single-instrument system (Reciproc; VDW, Munich, Germany) and a rotary multi-instrument system (BioRaCe; FKG Dentaire, La Chaux-de-Fonds, Switzerland) during the preparation of infected root canals of teeth with primary apical periodontitis. Methods Root canals from single-rooted teeth with necrotic pulps and apical periodontitis were instrumented using either Reciproc ( n = 29) or BioRaCe ( n = 30) instruments under irrigation with 2.5% sodium hypochlorite. DNA was extracted from samples taken before and after preparation and subjected to quantitative analysis of total bacteria and streptococci by using the quantitative real-time polymerase chain reaction. Results All initial samples were positive for the presence of bacteria, with median numbers of 7.1 × 10 5 and 1.31 × 10 5 bacterial cells for the Reciproc and BioRaCe groups, respectively. After preparation with Reciproc and BioRaCe, 16 (55%) and 15 (50%) root canals still had detectable bacteria with median counts of 7.05 × 10 2 and 6.03 × 10 1 , respectively. Both systems were highly effective in reducing the total bacterial counts ( P P > .05). Streptococci were highly frequent, and both systems succeeded in significantly reducing their levels ( P Conclusions Both reciprocating single-instrument and rotary multi-instrument systems were highly effective in reducing the counts of total bacteria and streptococci in root canals of teeth with apical periodontitis. Regardless of the system used, approximately one half of the teeth still had detectable bacteria.

This study used a multipurpose analytic approach to compare the levels of apically extruded bacterial and hard tissue debris as well as intracanal bacterial reduction after root canal preparation with either XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) or Reciproc (VDW, Munich, Germany) instruments.Distobuccal canals from extracted maxillary molars were contaminated with Enterococcus faecalis and randomly distributed into 2 groups according to the instrumentation system: the XP-endo Shaper or Reciproc. Teeth were mounted in an apparatus that simulates the apical resistance offered by the periapical tissues and permitted to collect debris extruded during preparation. Saline was used as the irrigant during preparation, and all treatment procedures were performed inside a cabinet under a controlled temperature of 37°C. DNA extracts from samples taken from the canal before and after preparation were subjected to quantitative real-time polymerase chain reaction for E. faecalis counting. The volume of extruded debris was evaluated by micro-computed tomographic imaging. DNA was extracted from the extruded hard tissue debris and analyzed by quantitative real-time polymerase chain reaction.Mechanical intracanal bacterial reduction was significantly more pronounced when using the XP-endo Shaper (P .001). Although both instruments produced a similar volume of extruded debris (P .05), extruded bacteria counts were significantly lower with Reciproc than the XP-endo Shaper (P .001). No correlation was observed between the extruded bacterial counts and debris volume.Although bacterial extrusion was lower with Reciproc, the intracanal bacterial reduction was higher with the XP-endo Shaper. Both techniques produced a similar volume of hard tissue debris extrusion.

AIM To evaluate the removal of accumulated hard-tissue debris (AHTD) from the root canal system of mandibular molars by positive and negative pressure irrigation systems, using micro-CT imaging analysis. METHODOLOGY Mandibular molars with a single canal in the distal root and 2 canals connected by an isthmus in the mesial root were matched based on similar morphological dimensions using micro-CT evaluation and assigned to 2 experimental groups (n = 20 mesial and 10 distal canals), according to the irrigation protocol: apical positive (conventional irrigation) or negative (EndoVac system) pressure. Changes in root canal volume and surface area as well as percentage of uninstrumented canal wall surface and accumulated hard-tissue debris (AHTD) after canal preparation were compared statistically using the independent sample t-test and Mann-Whitney U-test, with the significance level set at 5%. RESULTS Volume, surface area and percentage of static voxels in either mesial or distal root canal systems were not significantly different between groups before or after root canal preparation (P > 0.05). After preparation, AHTD was not observed in the distal canal of both groups. However, in the mesial root canal system, the conventional irrigation group was associated with a significantly higher median percentage of AHTD (11.48%; IQR: 5.9-22.6; range: 1.86-41.98) than the EndoVac group (3.40%; IQR: 1.5-7.3; range: 0.82-12.84) (P

This study compared the efficacy of HyFlex NT (HF; Coltene, New York, NY) and Mani GPR (MN; Mani Inc, Tokyo, Japan) systems followed by a supplementary approach with passive ultrasonic irrigation (PUI) in removing the filling material from curved root canals during retreatment. The mesial canals from 20 extracted mandibular molars with Vertucci type IV configuration were instrumented and obturated (N = 40). Each mesial canal was retreated using either HF or MN instruments, alternating the system used per canal from root to root. The final preparation size was 40/0.04 for both systems. The volume of canal filling material was assessed by means of micro-computed tomographic (micro-CT) imaging before and after retreatment, and the working time was recorded. Canals still showing remnants of filling material were subjected to a supplementary approach with PUI, and another micro-CT scan was taken. The percentage of filling material removed with MN instruments and HF was similar (95.5% and 92.7%, respectively) (P .05). MN required significantly less time to remove the filling material (P .05). The supplementary approach with PUI significantly enhanced the removal of filling material (P .05). Both systems were equally effective in removing the root canal filling during retreatment. MN was faster than HF. The supplementary approach with PUI significantly improved filling material removal.

The present study evaluated the cleaning and shaping ability of 3 instrumentation systems in oval canals of extracted vital teeth using a correlative analytic approach.Oval distal canals from 33 freshly extracted mandibular molars with pulp vitality were scanned by micro-computed tomographic (micro-CT) imaging for sample selection. Specimens matched by anatomic similarities were distributed into 3 experimental groups according to the instrument system to be evaluated: the Self-Adjusting File (SAF; ReDentNOVA, Ra'anana, Israel), TRUShape (Dentsply Sirona, Tulsa, OK), and XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland). The irrigant was 5.25% sodium hypochlorite heated at 37°C. After rescanning with micro-CT imaging, the unprepared surface areas were identified, measured, and then histologically evaluated for the amount of pulp remnants in each root third.When the apical 4-mm canal segment was evaluated, the SAF exhibited significantly less unprepared areas than the XP-endo Shaper (P .05), and there were no significant differences for the other comparisons (P .05). Analysis of the full canal length showed no statistically significant differences between the 3 tested systems (P .05). Likewise, the tested systems did not differ significantly in cleaning the unprepared walls (P .05).There was no significant difference in the amount of unprepared surface areas between the 3 instrument systems, except for the comparison between the SAF and XP-endo Shaper in the apical 4-mm segment. None of them prepared 100% of the root canal walls. The cleaning ability of the 3 systems was similar.

Introduction The purpose of this study was to evaluate the development of dentinal microcracks after root canal preparation with Reciproc and ProTaper Universal systems using an in situ cadaver model by means of a micro–computed tomography (micro-CT) imaging system. Methods At autopsy, 8 maxillary bone blocks having at least the first and second premolar teeth (n = 16) were excised, scanned at a resolution of 13.18 μm, and randomly distributed into 2 groups (n = 8) according to the preparation protocol: Reciproc and ProTaper Universal systems. Root canals were prepared up to R25 and F2 instruments in the Reciproc and ProTaper Universal groups, respectively. After the preparation procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 19,060) were screened to identify the presence of dentinal defects. Results In the Reciproc group, 9176 cross-section images were analyzed, and no crack was observed. In the ProTaper Universal group, 244 of 9884 cross-section slices (2.46%) had dentinal defects; however, all defects were already present in the corresponding preoperative images, indicating that no new microcrack was created after canal preparation. Conclusions In situ root canal preparation of maxillary premolars with Reciproc and ProTaper Universal systems did not induce the formation of dentinal microcracks in a cadaver model as observed by micro–CT.

Introduction A significant portion of the bacteria taking part of the microbiome associated with apical periodontitis still remain to be cultivated and phenotypically characterized. This molecular study evaluated the prevalence of selected as-yet-uncultivated and difficult-to-culture bacterial taxa in infected root canals and their susceptibility to chemomechanical procedures. Methods Root canals of single-rooted teeth with apical periodontitis were prepared using rotary nickel-titanium instruments and 2.5% sodium hypochlorite as the irrigant. DNA extracts from samples taken before (S1) and after (S2) chemomechanical preparation were surveyed for the presence of 7 as-yet-uncultivated phylotypes and 1 difficult-to-culture species using end-point polymerase chain reaction. Samples were also subjected to quantitative analysis of total bacteria and levels of the 2 most prevalent taxa. Results Bacteroidaceae sp. HOT-272 (24%) and Fretibacterium fastidiosum (20%) were the most prevalent taxa in S1. Their mean counts in S1 were 8.25 × 103 and 2.13 × 103 rRNA gene copies, corresponding to 0.18% and 0.55% of the total bacteria. Chemomechanical debridement promoted a highly statistically significant reduction in total bacterial counts (P < .001), but 64% of the canals were still positive for bacterial presence. Of the target taxa, only Bacteroidaceae sp. HOT-272 and F. fastidiosum were detected in S2 (each one in 1 sample). The reduction in counts of both taxa was also highly significant (P < .001). Conclusions Findings confirmed that several as-yet-uncultivated and difficult-to-grow bacterial taxa can participate in the microbiome associated with apical periodontitis. Two of them were found in relatively high prevalence but rarely as a dominant species. Chemomechanical procedures were highly effective in completely eliminating these taxa or at least substantially reducing their numbers.

Introduction An acute apical abscess is a severe response of the host to massive invasion of the periapical tissues by bacteria from infected root canals. Although many studies have investigated the microbiota involved in the process, information on the host factors released during abscess formation is scarce. The purpose of this study was to describe the human exoproteome in samples from acute apical abscesses. Methods Fourteen pus samples were obtained by aspiration from patients with an acute apical abscess. Samples were subjected to protein digestion, and the tryptic peptides were analyzed using a mass spectrometer and ion trap instrument. The human proteins identified in this analysis were classified into different functional categories. Results A total of 303 proteins were identified. Most of these proteins were involved in cellular and metabolic processes. Immune system proteins were also very frequent and included immunoglobulins, S100 proteins, complement proteins, and heat shock proteins. Polymorphonuclear neutrophil proteins were also commonly detected, including myeloperoxidases, defensins, elastases, and gelatinases. Iron-sequestering proteins including transferrin and lactoferrin/lactotransferrin were found in many samples. Conclusions The human exoproteome included a wide variety of proteins related to cellular processes, metabolism, and immune response. Proteins involved in different mechanisms against infection, tissue damage, and protection against tissue damage were identified. Knowledge of the presence and function of these proteins using proteomics provides an insight into the complex host-pathogen relationship, the host antimicrobial strategies to fight infections, and the disease pathogenesis.

Aim To microscopically examine the cleanliness of root canal walls that remained unprepared as revealed by micro-CT. Methodology The root canals of 10 freshly extracted mandibular premolars with necrotic pulps and apical periodontitis along with the mesiobuccal canals of 11 mandibular molars with vital pulps were prepared using Reciproc instruments R40 and R25, respectively, and 2.5% sodium hypochlorite irrigation. Specimens were scanned in micro-CT before and after preparation, and the unprepared areas were identified. The outer root surface corresponding to the untouched areas was marked on each root third to guide further analysis using histological (for teeth with vital pulps) and scanning electron microscopic (SEM; for necrotic teeth) examination. In the teeth with vital pulps, the root canal area occupied by tissue remnants was calculated. In SEM analysis of teeth with necrotic pulps, scores were attributed for the amount of debris on the untouched areas. Results The proportion of unprepared areas in the mesiobuccal molar canals was 18.1% and 9.6% over the full canal length and apical canal, respectively. In premolars, corresponding figures were 34.6% and 17.6%, respectively. Histological analysis of canals with vital pulps revealed tissue remnants over the untouched walls almost exclusively in the apical canal. SEM analysis of the canals with necrotic pulps revealed debris along the untouched walls in all root canal thirds. Conclusion The areas that remain untouched by Reciproc instruments used with 2.5% NaOCl irrigation as revealed by micro-CT analysis were usually covered with debris, in the form of pulp tissue remnants, bacteria and dentine chips, especially in the apical root canal.

The 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.Thirteen 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.Preparation 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).Both 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.

This study evaluated the disinfecting ability of chemomechanical preparation with rotary nickel-titanium instruments, followed by 2 distinct adjunctive procedures in the root canals of extracted mandibular molars by means of a correlative analytical approach.Twenty-two extracted mandibular molars were selected and anatomically matched between groups on the basis of micro-computed tomographic analysis. In the first phase of the experiment, root canals were contaminated with Enterococcus faecalis and subjected to chemomechanical preparation with BT RaCe instruments and 2.5% NaOCl irrigation. Then either XP-Endo Finisher instrument or passive ultrasonic irrigation was used to supplement disinfection. Micro-computed tomography was used to show whether the percentage of unprepared areas correlated to bacterial counts. In the second phase, the same teeth were contaminated once again, and the adjunctive procedures were used. Samples from the isthmus area of mesial roots and the apical 5-mm fragment of distal roots were obtained by cryopulverization. Samples taken before and after treatment steps in both phases were evaluated by quantitative polymerase chain reaction and statistically analyzed.In phase 1, preparation in both groups resulted in substantial decrease of bacterial counts (P .001). The adjunctive approaches led to a further small bacterial reduction, which was significant for XP-Endo Finisher (P .05). No significant differences were observed between groups for persisting bacterial counts. Correlative analysis revealed no statistically significant relationship between bacterial reduction and the percentage of unprepared areas (P .05). In phase 2, both methods had significant antibacterial effects in the main canal, but none of them could predictably disinfect the isthmus/recess areas.Both XP-Endo Finisher and passive ultrasonic irrigation exhibited antibacterial effectiveness, but only the former caused a significant reduction in the bacterial counts after chemomechanical preparation. None of them were effective in predictably disinfecting the isthmus/recess areas.

This study compared the efficacy of a reciprocating single-instrument system and a rotary multi-instrument system followed by a supplementary approach with a finishing instrument in removing the filling material from curved canals during retreatment.Forty mesial canals from extracted mandibular molars were instrumented and filled. Then, each mesial canal was retreated by using either Reciproc (VDW, Munich, Germany) or Mtwo (VDW) instruments, alternating the technique used per canal from root to root. The working time was recorded, and the percentage of removed filling volume was assessed by means of micro-computed tomography imaging before and after retreatment. Canals still showing filling material remnants were subjected to an adjunctive approach with the XP-Endo Finisher (FKG Dentaire, La Chaux-de-Fonds, Switzerland), and another microCT scan was taken. Data were statistically analyzed with a significance level of 5%.The percentage of filling material removed with Mtwo instruments (96%) was significantly higher than Reciproc (89%) (P .05), both used up to a final instrument size of 40. Mtwo required less time to remove the filling material than Reciproc (P .05). Intragroup analysis in the Reciproc group showed that the R40 instrument removed significantly more filling material than R25 (P .05). The supplementary approach with the XP-Endo Finisher was effective in significantly enhancing the removal of filling material (P .05).The rotary multiple-instrument system was more effective and faster than the reciprocating single-instrument approach in removing previous root canal fillings. As for the Reciproc group, it was observed that the larger instrument promoted significantly better results. The adjunctive finishing instrument XP-Endo Finisher significantly improved filling material removal.

Objective Herpesvirus infection can cause immunosuppression and then act as a modifier of apical periodontitis, influencing the disease severity and response to treatment. The purpose of this study was to investigate if herpesvirus infection, as inferred by salivary carriage, may influence the endodontic treatment outcome. Study design The study population included 72 patients who had root canals treated more than 1 year previously because of necrotic pulps and apical periodontitis. At the follow-up examination, 27 of these patients presented with posttreatment apical periodontitis (failure) and 45 individuals exhibited healed/healing periradicular tissues (success). Saliva was collected from these individuals, DNA was extracted, subjected to multiple displacement amplification, and screened by polymerase chain reaction (PCR) assays for the presence of 6 herpesviruses: herpes simplex virus types 1 and 2 (HSV-1/2), Epstein-Barr virus (EBV), human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), and human herpesvirus-8 (HHV-8). Results Except for HSV-1/2, all other herpesviruses were detected in saliva from both healed/healing and diseased groups. HHV-8 was the most frequent herpesvirus found in saliva (84% in success, 89% in failure), followed by HCMV (22% in success, 30% in failure), EBV (16% in success, 18.5% in failure) and HHV-6 (7% in success, 15% in failure). No significant association of herpesvirus carriage in saliva with poor treatment outcome was discernible in the population studied (P > .05). Conclusions Data from the present study suggest that herpesvirus infection may not influence the outcome of endodontic treatment. Further longitudinal studies are warranted to confirm these findings.

Introduction Polymorphisms of genes encoding leukocyte surface receptors for the constant region of immunoglobulin G (FcγR) might influence the host response to infection and consequently affect the outcome of the endodontic treatment. This study investigated the association of FcγRIIIa gene (FcγRIIIA) polymorphism with post-treatment apical periodontitis in Brazilian subjects. Methods The study population consisted of 26 patients with post-treatment apical periodontitis and 43 subjects with root canal–treated teeth exhibiting healthy/healing periradicular tissues (controls). All teeth had apical periodontitis lesions at the time of treatment, which was completed at least 1 year previously. Saliva was collected from the participants; DNA was extracted and used for FcγRIIIA genotyping. Results No significant associations were found between any specific genotype of FcγRIIIA ( P = .63) or allele ( P = .76) and post-treatment apical periodontitis. Overall, the most prevalent allele in the study population was FcγRIIIA-F158 (68.8%). The genotype V/F was the most common among the population, occurring in 50.7% of the subjects. Conclusions Data from the present study suggest that polymorphism in the FcγRIIIa does not influence the patient’s response to endodontic treatment of teeth with apical periodontitis.

Introduction Genetic polymorphisms have been reported to act as modifiers of diverse diseases and, as such, might theoretically influence the severity and response to treatment of apical periodontitis. The purpose of this study was to investigate the association of Fcγ receptor and interleukin (IL)-1 gene polymorphisms with post-treatment apical periodontitis in Brazilian individuals. Methods The study population consisted of 18 patients with post-treatment apical periodontitis and 44 individuals with root canal–treated teeth exhibiting healthy/healing periradicular tissues (controls). Patients were typed for the following genes (alleles): FcγRIIA (R131 or H131), FcγRIIIB (NA1 or NA2), IL-1A (1 or 2), and IL-1B (1 or 2). Results No significant statistical differences were observed for all specific genotypes and almost all allele carriage rates of the test genes as well as combinations thereof with regard to association with disease (P > .05). Actually, only 2 genetic conditions were found to be associated with post-treatment apical periodontitis: carriage of allele H131 of the FcγRIIa gene (P = .04) and a combination of this allele with allele NA2 of the FcγRIIIb gene (P < .01). Conclusions Data from the present study suggest that some conditions associated with polymorphism of Fcγ receptor genes might influence the patient's response to endodontic treatment of teeth with apical periodontitis.

Objective. This study investigated the long-term (1-4 years) outcome of the endodontic treatment of teeth with apical periodontitis lesions performed by undergraduate students using a defined antimicrobial protocol. Study design. Treatment protocol included a crown-down instrumentation technique, apical enlargement to predetermined sizes and apical level, irrigation with 2.5% sodium hypochlorite, and intracanal medication with calcium hydroxide/camphorated paramonochlorophenol (CPMC) paste. The first 100 teeth from patients who returned for follow-up were examined. The outcome was assessed based on radiographic and clinical criteria as healed (success), healing (uncertain), or not healed (failure). Results. Overall results showed that 76% of the teeth healed, 19% were healing, and 5% had not healed. Most healed cases (75%) or failed cases (80%) were already evident at 2 years. Seven cases took 4 years to heal completely. Conclusions. The low failure rate observed in this study reinforces the importance of using an evidence-based antimicrobial strategy during endodontic treatment of teeth with apical periodontitis. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:757-62)

This randomized clinical study compared the antibacterial effects of irrigation with either 2.5% sodium hypochlorite (NaOCl) or 2% chlorhexidine (CHX) during the preparation of infected root canals with rotary nickel-titanium instruments.The root canals of 50 single-rooted teeth with apical periodontitis were prepared by using BioRaCe rotary instruments (FKG Dentaire, La Chaux-de-Fonds, Switzerland) and irrigation with either 2.5% NaOCl (n = 25) or 2% CHX (n = 25). Samples were taken from the canal at baseline (S1) and after (S2) chemomechanical preparation. DNA was extracted from the clinical samples, and the reduction of the levels of total bacteria and streptococci was evaluated by means of a 16S ribosomal RNA gene-based quantitative polymerase chain reaction assay.All S1 samples were positive for the presence of bacteria. After chemomechanical preparation using either 2.5% NaOCl or 2% CHX, 44% and 40% of the root canals still had detectable bacteria, respectively. As for total bacterial counts, a mean number of 3.7 × 10(5) bacterial cell equivalents was present in S1 samples from the NaOCl group, with a substantial reduction in S2 to a mean of 5.49 × 10(2) cell equivalents (P .001). In the CHX group, a mean bacterial load of 8.77 × 10(4) cell equivalents occurred in S1, with a significant reduction in S2 to a mean of 2.81 × 10(3) cells (P .001). The differences in both the presence/absence and quantitative data were not statistically significant (P .05). Both irrigation protocols were highly effective in reducing the levels of Streptococcus species (P .001).No significant difference was observed for the clinical antibacterial effectiveness of rotary preparation using either 2.5% NaOCl or 2% CHX as the main irrigant.

Introduction Short-chain fatty acids (SCFAs) are bacterial metabolic end products that may function as virulence factors. This study evaluated the occurrence of SCFAs in infected root canals before and after treatment. Methods Samples were taken from root canals of teeth with apical periodontitis before (S1) and after (S2) chemomechanical preparation with either NaOCl or chlorhexidine as the irrigant and then after interappointment medication with calcium hydroxide (S3). High-performance liquid chromatography was used for detection of SCFAs. Selected bacterial taxa that are recognized producers of the target SCFAs were identified by real-time polymerase chain reaction. Results Butyric acid was the most common fatty acid in S1, followed by propionic acid. Both molecules were also found in S2 and S3 from both NaOCl and chlorhexidine groups. Lactic acid was not present in detectable levels in S1, but it occurred in 1 postinstrumentation sample and in 9 samples taken after calcium hydroxide medication. Of the target taxa, Fusobacterium nucleatum was the most prevalent in S1 (76%), followed by members of the Actinobacteria phylum (71%), Streptococcus species (59%), and Parvimonas micra (53%). Gram-positive taxa, especially streptococci, were the most prevalent bacteria in S2 and S3. SCFA detection was matched with the respective potential producer species in most cases. Conclusions This first report of SCFAs in infected root canals suggests that these molecules may play a role in the pathogenesis of apical periodontitis. Significance of persistence of SCFAs after treatment and its effects on the long-term outcome await elucidation.

Analysis of the metaproteome of microbial communities is important to provide an insight of community physiology and pathogenicity. This study evaluated the metaproteome of endodontic infections associated with acute apical abscesses and asymptomatic apical periodontitis lesions. Proteins persisting or expressed after root canal treatment were also evaluated. Finally, human proteins associated with these infections were identified. Samples were taken from root canals of teeth with asymptomatic apical periodontitis before and after chemomechanical treatment using either NaOCl or chlorhexidine as the irrigant. Samples from abscesses were taken by aspiration of the purulent exudate. Clinical samples were processed for analysis of the exoproteome by using two complementary mass spectrometry platforms: nanoflow liquid chromatography coupled with linear ion trap quadrupole Velos Orbitrap and liquid chromatography-quadrupole time-of-flight. A total of 308 proteins of microbial origin were identified. The number of proteins in abscesses was higher than in asymptomatic cases. In canals irrigated with chlorhexidine, the number of identified proteins decreased substantially, while in the NaOCl group the number of proteins increased. The large majority of microbial proteins found in endodontic samples were related to metabolic and housekeeping processes, including protein synthesis, energy metabolism and DNA processes. Moreover, several other proteins related to pathogenicity and resistance/survival were found, including proteins involved with adhesion, biofilm formation and antibiotic resistance, stress proteins, exotoxins, invasins, proteases and endopeptidases (mostly in abscesses), and an archaeal protein linked to methane production. The majority of human proteins detected were related to cellular processes and metabolism, as well as immune defense. Interrogation of the metaproteome of endodontic microbial communities provides information on the physiology and pathogenicity of the community at the time of sampling. There is a growing need for expanded and more curated protein databases that permit more accurate identifications of proteins in metaproteomic studies.

Introduction This study investigated the association of CD14 -260C>T and TLR4 +896A>G gene polymorphisms with post-treatment apical periodontitis in Brazilian individuals. Methods The study population consisted of 41 patients with post-treatment apical periodontitis and 42 individuals with root canal–treated teeth exhibiting healed/healing periradicular tissues (controls). All teeth had apical periodontitis lesions at the time of treatment, which was completed at least 1 year previously. Saliva was collected from the participants; DNA was extracted and used for CD14 and TLR4 genotyping using the polymerase chain reaction–restriction fragment length polymorphism approach and a real-time polymerase chain reaction TaqMan assay (Applied Biosystems, Foster City, CA), respectively. Results No specific genotype or allele of the CD14 and TLR4 genes or any combination thereof was positively associated with post-treatment apical periodontitis (P > .05). Conclusions Data from the present study suggest that polymorphisms in the CD14 and TLR4 genes do not influence the response to endodontic treatment of teeth with apical periodontitis.

Svrha istraživanja bila je ocijeniti i usporediti antibakterijsku učinkovitost pet retrogradnih punila korijenskih kanala. Materijal i metode: Metodom difuzije u agru ocijenjena je zona inhibicije bakterijskog rasta na podlozi pet retrogradnih punila korijenskih kanala: Pro Root MTA, cementa Portland, Super-EBA, IRM-a, Sealera 26 te amalgama. Za ciljane mikroorganizme bilo je odabrano pet anaeroba (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes i Eubacterium saburreum) te dva fakultativna (Actinomyces viscosus i Enterococcus faecalis). Rezultati: Sealer 26 postigao je najveću inhibiciju rasta. Punila IRM i Super-EBA spriječila su rast samo Porphyromonas gingivalis, ali učinak je bio znatno slabiji u usporedbi s djelovanjem Sealera 26. Kao neučinkovita antibakterijska sredstva pokazali su se MTA, cement Portland i amalgam. Zaključak: Rezultati istraživanja potvrdili su da Sealer 26 ima najjače antibakterijsko djelovanje u usporedbi s ostalim često upotrebljavanim apikalnim punilima korijenskih kanala., Purpose: The present study was undertaken to evaluate and compare the antibacterial effectiveness of five root-end filling materials. Material and methods: The agar diffusion method was employed to evaluate the inhibition zone provided by the following root-end filling materials: Pro Root MTA, Portland cement, Super-EBA, IRM, Sealer 26, and silver amalgam. The target microorganisms included five anaerobic bacterial species (Porphyromonas gingivalis, Parvimonas micra, Fusobacterium nucleatum, Propionibacterium acnes and Eubacterium saburreum) and two facultative bacterial species (Actinomyces viscosus and Enterococcus faecalis). Results: Sealer 26 demonstrated the largest inhibitory effects on all species tested. IRM and Super-EBA were inhibitory only to P. gingivalis, but this effect was far less pronounced as compared to Sealer 26. MTA, Portland cement, and amalgam proved ineffective against all species tested. Conclusion: These findings revealed that Sealer 26 has more pronounced antibacterial effects when compared to other commonly used root-end filling materials.

Evidence suggests that diabetic patients are more significantly affected by problems of endodontic origin. This study sought to radiographically and histologically examine the development of periradicular inflammation in control and in diabetic rats after induction of pulpal infection. The pulps of the mandibular first molars of normal and streptozotocin-induced diabetic rats were exposed and left in contact with their oral cavities for 21 and 40 days. Afterwards, the animals were sacrificed, the mandibles were surgically removed, fixed in formalin and then radiographed in a standardized position. The radiographic images of the periradicular lesions were scanned and computerized images were evaluated for the total area of the lesions using a specific software. Representative specimens were also prepared for histopathological analysis. Radiographic analysis revealed that diabetic rats presented significantly larger periradicular lesions when compared with control rats, regardless of the experimental period (p