Straight Root Research Articles

Efficacy of Different Endodontic Irrigant Activation Systems on Smear Layer Removal and Canal Cleanliness: Comparative Scanning Electron Microscopic Study

AIM: This study assessed the effectiveness of 5 different irrigant activation systems on canal cleanliness and removal of smear layer from root canals. METHODS: A total of 110 mandibular premolars with straight root canal were assigned to five groups (n = 20): conventional needle irrigation, passive ultrasonic activation, sonic activation with EndoActivator, negative apical pressure EndoVac (EV), or EDDY system, besides a control group (n = 10). All teeth were prepared to size 40, and irrigated with NaOCl (5.25%) according to the respective technique. Roots were split longitudinally and subjected to scanning electron microscopic analysis. The presence of smear layer and debris was evaluated using 5-grade scoring systems with ×1000 and ×400 magnification, respectively. Data were analyzed at 5%. RESULTS: Regarding the smear layer, activation with EV and ED was significantly more effective than other activation groups (p < 0.05). Activation of the irrigant significantly improved removal of debris (p < 0.05). CONCLUSION: No activation technique was able to eliminate smear layer and debris completely from root canals, nevertheless, EDDY is significantly better in removing debris and smear layer from the apical third of the canal.

The analysis of root canal curvature and direction of maxillary lateral incisors by using cone-beam computed tomography: A retrospective study.

The aim of this study was to investigate root canal curvature and direction of maxillary lateral incisors in Shandong, China.Cone beam computed tomography (CBCT) images of 176 maxillary lateral incisors of 88 patients were collected in Shandong Province, China. Software included with CBCT was used to measure the angle of root canal curvature of maxillary lateral incisors on the maximum bending plane. In addition, the direction of each root canal was recorded. The data were statistically analyzed by SPSS 17.0 software package.The results showed that all the samples had a single canal (Vertucci's type I). The incidence of straight root canals, curved root canals, and S-type root canals was 39.2%, 58%, and 2.8%, respectively. The difference in the mean angle of root canal curvature failed to identify any differences between the left and right side (P > .05). The most curved root canal of maxillary lateral incisors oriented in the palato-distal direction.The maxillary lateral incisors were mainly curved root canals of which the proportion of moderate curvature was the largest. Software included with CBCT would provide some valuable information for root canal instrumentation of maxillary lateral incisors.

A Comparative Evaluation of Antimicrobial Efficacy of Triphala and Calcium Hydroxide as Intracanal Medicament: An In Vitro Study.

Background:The goal for placement of intracanal medicament during pulpal therapy procedures is to eradicate the bacteria and the exotoxins from the infected root canal, thereby preventing and controlling pulpal and periradicular infections. Chemo-mechanical preparation is considered an essential step in root canal disinfection; but to accomplish the total elimination of bacteria in highly complex root canal anatomy is difficult. Intracanal medicaments help eliminate bacteria by remaining in the root canal, and calcium hydroxide has been recommended as one of the most effective antimicrobial dressings during endodontic therapy. The herbal agents offer an alternative to synthetic compounds. They have been considered either non-toxic or less toxic. The rapid increase in antibiotic-resistant strains and side effects caused by synthetic drugs have prompted researchers to look for herbal alternatives.Aim and Objective:The in vitro study aims to evaluate and compare the antibacterial activity of triphala and calcium hydroxide against Enterococcus faecalis as an intracanal medicamentMaterials and Methods:The antimicrobial efficacy of triphala and calcium hydroxide was evaluated against E. faecalis cultured and incubated for various time frames in 42 intact, caries-free, human, single-rooted teeth with straight roots and mature apices. The comparison of the number of counted colonies after each incubation time and based on the type of drug used inside the canal is evaluated using non-parametric Kruskal–Wallis test and Mann–Whitney U test, respectively. Statistical analysis was done using SPSS version 14.0.Results:Efficacy of calcium hydroxide against Enterococcus faecalis was best in the first 72-hr time duration compared with triphala. Triphala showed significant antimicrobial activity against Enterococcus faecalis that was closely parallel to the calcium hydroxide group in one week. Calcium hydroxide and triphala had complete eradication of Enterococcus faecalis in a given one-month time duration.

Comparative evaluation of incidence of dentinal defects after root canal preparation using hand, rotary, and reciprocating files: An ex vivo study

Aim: To compare dentinal cracks incidences after root canal preparation using Hand K-files; Rotary files: Protaper NEXT (PTN), Hyflex Controlled Memory (CM); and Reciprocating files: Wave One and Wave One Gold files. Materials and Methods: Hundred extracted human mandibular first premolars with straight root canals were taken postextraction and were allocated randomly into five groups (n = 20 teeth per group). The canals were instrumented using Hand K-files, Protaper Next (PTN), Hyflex CM, Wave One, and Wave One Gold systems. Group 1-Control group comprised of canals prepared by Hand files. Further, the roots were sectioned at three levels: 3, 6, and 9 mm horizontally from the apex using a saw at a low-speed saw and under water cooling. These slices were examined under a stereomicroscope at 25× magnification and the presence of any dentinal cracks was noted. The frequency of cracks was presented in number and percentage. Intergroup comparison of crack frequency was performed using analysis of variance. Results: No cracks were observed in the control group. In all the other groups, dentinal cracks were observed. The rotary files PTN and Hyflex CM files produced significantly fewer dentinal cracks than the reciprocating Wave One and Wave One Gold files (P < 0.05). The reciprocating files significantly produced more cracks apically than the rotary files (P < 0.05). Analyses were performed on SPSS software (windows version 22.0). Conclusion: Instrumentation with file systems can cause crack formation in the dentinal wall of the root canal. Determination of which files to choose for root canal preparation is technique sensitive and each instrument type has own benefits. However, care should be taken while biomechanical preparation to avoid dentinal cracks formation.

Calcium Hydroxide Removal Using Four Different Irrigation Systems: A Quantitative Evaluation by Scanning Electron Microscopy

This study compares conventional endodontic needle irrigation, passive ultrasonic irrigation, apical negative pressure irrigation, and mechanical activation to remove calcium hydroxide from single straight root canals. Eighty-four mandibular premolars were prepared in a crown-down manner up to size #40. Two teeth represented a negative control, and another two served as a positive control. Calcium hydroxide paste was placed inside root canals. The remaining eighty samples were analyzed based on the activation techniques, and the cleanliness of the canals was quantified using Fiji’s software on 500× magnified SEM backscattered electron micrographs. Considering the whole canal, all instruments showed better performance than conventional endodontic needle irrigation in removing calcium hydroxide (p &lt; 0.05). Irrisafe and XP-endo Finisher could remove a significantly higher amount of calcium hydroxide than Endovac (p &lt; 0.05). Irrisafe and XP-endo Finisher have been able to remove more calcium hydroxide than EndoVac.

Coronectomy of deeply impacted mandibular third molars: Socio-demographics and sequelae after one year evaluation in a Saudi Arabian Sub-population

BackgroundCoronectomy is a surgical procedure to prevent Inferior Alveolar Nerve (IAN) injury when extracting Impacted Mandibular Third Molars (IMTM’s). The aim of the present study was to report the sequelae of coronectomy. Materials and methodsThis is a prospective study of patients referred for surgical extraction of IMTM’s. Baseline investigations (panorama and CBCT) were done. Relationship between IMTM’s and IAN was defined as “contact, involvement and overlap”. Coronectomy procedure was carried out and recall visits at Times 1, 2 and 3 arranged. The effect of coronectomy on root migration on variables was determined using ANOVA. ResultsSeventy-three patients (24 (32.9%) males and 49 (67.1%) females) had coronectomy. Mean age ± SD (28.2 ± 6.7) and M:F (1:2) was observed. Sixty-five (89.0%) patients presented at Time 1 with 2.6 ± 0.62 mm root migration, while 55(84.6%) and 32 (58.2%) patients presented for Times 2 and 3 with root migration of 3.5 ± 0.76 mm and 4.0 ± 0.79 mm respectively. The migration rate was significant at 1st (p = 0.000), 2nd (p = 0.001) and 3rd (p = 0.000) review periods in the females. SFSR (Single Fused Straight Root) had the highest rate of migration with significance at 2nd and 3rd review periods (p = 0.035 and 0.029) respectively. ‘Contact’ relationship has the highest frequency and followed by ‘overlap’ relationship (42 (57.5%) and 24 (32.9%)) respectively. ‘Involvement’ relationship was the least with 7 (9.6%) cases. ConclusionThe present study showed that following coronectomy, there is rapid migration of remaining roots away from the IAN as observed in females, patients with conical/fused roots and the 31-40years.

Stress distribution of a novel bundle fiber post with curved roots and oval canals.

The aim of this study was to compare the stress distribution of teeth with curved and straight roots with oval and round canals restored with the bundle and conventional post systems. Six three-dimensional premolars were modeled with round and oval canals, and curved roots using the software. The bundle post and the round posts were modeled. All post models were placed on the canals. The models were subjected to 200 N oblique loading. The results were evaluated by von Mises stresses. This study demonstrated that the bundle post showed higher stress values compared to the conventional post. The stresses in the oval canal were higher than those in the round canal. The highest stress values were found in the curved roots. The stress distribution on the curved roots was observed in the middle and apical third of the canal. The bundle post presented higher stress compared to conventional posts. Besides, a more uniform stress distribution was observed in the bundle groups. When a post was required in extremely irregular, wide canals and curved roots, the bundle post was the material of choice. Canal and root morphology influenced stress distribution.

On the weld root fatigue strength and improvement techniques for non-load-carrying transverse attachment joints with single-sided fillet welds and made of mild and ultra-high-strength steels

The present study experimentally and numerically investigates the fatigue strength of non-load-carrying transverse attachment joints prepared with single-sided fillet weld. Constant amplitude fatigue tests are carried out on specimens made of S355 and S1100 steel grades to obtain the fatigue strength of these joints. In addition, the study evaluates fatigue life improvement technique for these joints comprising the use of a curved plate edge shape in the attachment, which results in varying weld penetration and weaved weld root shape. Numerical analyses are carried out to determine the applicability of the effective notch stress concept in assessing the fatigue strength of the studied joints. The experimental results show that the weld root to the base plate is the critical fatigue failure mechanism, and characteristic design fatigue strengths of FAT97.7% = 109 MPa and FAT97.7% = 97 MPa (with a slope parameter of m = 3) in the nominal stress system for the S355 and S1100 grades with a straight root geometry are obtained, respectively. Using a curved plate edge shape and varying weld penetration, the fatigue strength could be improved by up to 25% for the S1100 grade. The numerical analyses reveal that the effective notch stress modeling technique of the fictitious notch radius significantly affects the stress concentration factors, while the fillet-type modeling technique at the weld root showed more accurate results than the keyhole shape.

Influence of conservative endodontic access cavities on instrumentation of oval-shaped straight root canals.

To evaluate the influence of the design of endodontic access cavities on the percentage of unprepared areas of canal walls and flexural fatigue of instruments activated by reciprocating movement in oval-shaped straight root canals of extracted teeth. Forty-two mandibular incisors with oval canals were scanned by a microcomputed tomography (micro-CT) device for homogeneous selection and distribution of the samples. Then, the teeth were divided into two groups (n=21) according to the design of access cavity being tested: ultraconservative endodontic access cavity (UltraAC) and traditional access cavity. The canals were accessed with the aid of a surgical microscope, instrumented with the WaveOne Gold Medium system and irrigated with 2.5% NaOCl and 17% EDTA. The unprepared areas of the canal wall were analysed by overlaying images before and after instrumentation and expressed as percentages. micro-CT data were analysed using t-test, Mann-Whitney and Wilcoxon tests. The endodontic instruments used during instrumentation were subjected to static flexural fatigue testing using an artificial stainless steel canal with a 60° angle of curvature and a radius of 5mm, located 5mm from the tip of the instrument. The instruments were activated until fracture occurred, and the time in seconds for the fracture was recorded using a digital timer. The number of cycles to fracture was calculated and analysed statistically. For flexural fatigue data, an anova test complemented by a Tukey range test was used. The significance level of 5% was used for all analyses. There was no significant difference between the groups related to unprepared areas by the instrument during canal preparation (p>.05). The difference in flexural fatigue resistance between the groups was not significant. The use of UltraAC did not interfere with the canal instrumentation of extracted mandibular incisors with straight and oval canals. There was no difference in the flexural fatigue resistance of the instruments in relation to access cavity design.

English

BACKGROUND The factors that influence the implant accuracy are the anatomy of the patient, the experience of the practitioner and the surgical approach. However, the relative importance of each factor is poorly understood. Favourable function, occlusion, aesthetics and implant loading patterns can be obtained by optimal positioning. The experience of the surgeon is of utmost importance for the skill of placing a dental implant with proper angulation. The purpose of this retrospective study was to determine the increased accuracy obtained in performing freehand surgical placement of implants. METHODS This study was conducted in the Department of Implantology. A total of 1216 postoperative periapical radiographs from which single implant placement with adjacent straight root morphology was collected from the department in the period of June 2019 to June 2020 and checked for angulation, practitioner’s experience and the site of placement. Mesio-distal angulation was calculated. Statistical analysis was performed using the SPSS method. RESULTS The results showed accuracy in angulation and positioning of implants increased with an increase in experience of the dental surgeon (oral surgeons, prosthodontists, periodontists). Within the limitations of the study, it showed that the freehand dental implant placement angulation was less than a degree for experienced surgeons. The postgraduates had a better understanding and orientation of the angulation than the undergraduates. Moreover, the difficult site was the second and third quadrant to assess the angulation properly. CONCLUSIONS With proper assessment of the anatomy and with experience freehand dental implant placement shows significant results with less angulation which can be prosthetically accepted. KEY WORDS Free Hand Surgery, Guided Surgery, Angulation Of Implants.

The Effect of Photodynamic Therapy on the Smear Layer Removal: a Scanning Electron Microscopic Study.

Statement of the Problem: The efficacy of photodynamic therapy (PDT) in smear layer removal compared to the currently accepted protocol is not well established.Purpose: This study aims to evaluate the effect of PDT on smear layer removal from human root canal compared to combined use of irrigation solutions including sodium hypochlorite (NaOCl) and ethylene diamine tetra acetic acid (EDTA) by scanning electron microscopy (SEM).Materials and Method: In this in vitro study, straight roots from 48 extracted human maxillary incisors and canines were selected and decoronated. Instrumentation was completed with RaCe rotary system and normal saline irrigation between files. Then roots were randomly divided into 3 groups (n=16). Group 1 was the control group to confirm smear layer formation. In the group 2, the canals were irrigated with 2ml of 2.5% NaOCl solution for 10 minutes and 2ml of 17% EDTA solution for 1 minute. In the group 3, PDT with methylene blue and diode laser (625nm, 150mW, for 5minutes) was the final procedure for smear layer removal. All the specimens were sectioned into two halves, gold coated, and analyzed under SEM. The smear layer in the coronal, middle, and apical thirds, were evaluated and scored by two examiners independently. Statistical analysis was done using Chi-square test.Results: It was observed that the NaOCl+EDTA removed the smear layer significantly better than PDT in the coronal and apical thirds (p< 0.05) whereas PDT was unable to remove the smear layer in none of the root areas. At the apical thirds, there was no significant difference between NaOCl+EDTA and PDT (p< 0.05). Both procedures were unable to remove smear layer from radicular dentine of this area.Conclusion: According to the results of this in vitro study, the use of PDT alone is not recommended to remove smear layer. The combined application of NaOCl and EDTA is ineffective in removing smear layer of apical third, despite its efficacy on the coronal and middle regions.

A review on the effect of using rotary hyflex electrical discharge machining endodontic files on the formation of dentinal microcracks in straight root canals

Endodontic therapy is based on cleaning and shaping the canal system till the apex with total obturation of the canal. However, it is not always straightforward. Endodontics specialists face many complicated cases as sever curved canals, calcified canals and canals with previously initiated therapy which require to deal with. dental professionals pay attention to create new methods or to improve the already developed equipment and procedures to facilitate their work. Rotary endodontics files are in the center of attention. nowadays, recent files with extraordinary properties have been revolutionized. The standard Nickel Titanium rotary endodontic files are not always preferred. It cannot serve well in the aforementioned complex cases due to its larger tapers and unique shape memory property. Moreover, these files have led to several dentinal microcracks formation during canal preparation using the flaring instruments. Microcracks are evaluated through the accurately presented sliced images using Micro-Computer Tomography (micro-CT) done before and after root canal preparation. This has led to the invention of new generations of rotary endodontics files, with unique properties improving its behavior during the instrumentation, including Controlled Memory (CM) files and Electrical discharge Machine (EDM) files, opening the door for a new era in the field of endodontics dentistry. The present study aims to review HyFlex EDM files, including their properties, clinical dental usage, and the role of micro-CT in analyzing dentinal micro cracks formed with HyFlex EDM files.

Push-Out Bond Strength Evaluation of Fiber-Reinforced Composite Resin Post Cemented with Self-Adhesive Resin Cement Using Different Adhesive Bonding Systems.

The purpose of this in vitro study was to evaluate the push-out bond strength of fiber-reinforced resin posts using self-adhesive cements with different adhesive systems. A total of 50 single-rooted human maxillary premolars with fully developed apices and 15–16 mm straight root canals were selected. The teeth were divided into 10 groups with coronal and apical parts according to the adhesive bonding system and luting material used: one universal adhesive with MDP-containing self-adhesive resin cement; another universal adhesive with MDP-containing self-adhesive resin cement; universal primer with MDP-containing self-adhesive resin cement; universal primer with dual-cure resin cement; MDP-containing self-adhesive resin cement only (Control). Each specimen was subjected to a fatigue load of 600,000 cycles using a chewing simulator with sliding movement and cut horizontally for push-out bond strength testing. Statistical evaluation consisted of a one-way ANOVA test using SPSS v23.0. The highest bond strength (7.05 MPa) was obtained in the coronal part of the Single Bond universal group treated with MDP-containing self-adhesive resin cement and the lowest strength (4.77 MPa) was observed in apical part of MDP-containing self-adhesive resin cement group (Control). However, the one-way ANOVA results showed no significant difference between all 10 groups (p > 0.05). The self-adhesive cement without adhesive bonding showed no statistically different value compared to self-adhesive cements with adhesive bonding.

CBCT Evaluation of Gutta-Percha Removal Using Protaper and Mtwo Retreatment Files, Wave One, and Hedstrom Files: An Ex Vivo Study.

Objectives: This study aimed to evaluate the efficacy of ProTaper, Mtwo, and WaveOne retreatment files and Hedstrom files for removal of gutta-percha from the straight root canals using cone-beam computed tomography (CBCT). Materials and Methods: Forty freshly extracted single-rooted and single-canal teeth were selected for this study. The teeth were decoronated, and biomechanical preparation was performed up to #30 K-file. The root canals were obturated using lateral compaction technique with gutta-percha and Resilon sealer. The teeth were then randomly divided into 4 groups, and CBCT images were obtained. All the canals were then retreated with either ProTaper retreatment files, Mtwo retreatment files, WaveOne files, or Hedstrom files. The surface area of the remaining filling material after the retreatment procedure was quantified by CBCT. Statistical analysis was performed via one-way ANOVA and the Tukey-Kramer multiple comparisons test. Results: None of the file systems could completely remove the filling material from the canals. Data analysis revealed significant differences between the groups in the apical and middle thirds (P<0.05). Conclusion: All the file systems left some filling material in the canals. Mtwo retreatment files had maximum efficacy for removal of filling materials in comparison with other files. WaveOne files can also be used for root canal retreatment.

Evaluation of the effectiveness of reciprocal and conventional shaping systems and EDDY and CanalBrush activation systems in calcium hydroxide removal

Aim: To compare the effectiveness of two preparation systems and two irrigation techniques in calcium hydroxide removal from straight root canals.&#x0D; Methodology: Forty-four mandibular premolar teeth were included in this study. The teeth were filled with a calcium hydroxide-based paste and randomly divided into two different preparation groups (Reciproc 50 (R50; VDW, Munich, Germany and ProTaper Universal F5 (PTU; Dentsply Maillefer, Ballaigues, Switzerland). Subsequently, the groups were divided into two subgroups and irrigated using EDDY (VDW, Munich, Germany) and CanalBrush (CB; Roeko, Langenau, Germany) irrigation activation systems. The percentage of calcium hydroxide removed from the canal walls was analyzed using a dental operating microscope (DOM) at 25× magnification. An independent samples t-test, a Mann–Whitney U, Wilcoxon’s tests were used for statistical analysis.&#x0D; Results: There was no significant difference in calcium hydroxide removal throughout the root canal using the R50 and PTU F5 preparation systems (P = 0.847). Both activation systems significantly increased the amount of calcium hydroxide removed from the root canal. Conclusions: EDDY and CB significantly improved calcium hydroxide removal. There was no significant difference between the R50 and PTU F5 systems in calcium hydroxide removal.&#x0D; How to cite this article: Keskin NB, İnce Yusufoğlu S. Evaluation of the effectiveness of reciprocal and conventional shaping systems and EDDY and CanalBrush activation systems in calcium hydroxide removal. Int Dent Res 2021;11(1):16-22. https://doi.org/10.5577/intdentres.2021.vol11.no1.4&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The influence of different working lengths on apically extruded debris

Aim: To evaluate the influence of three different working lengths on the amount of apically extruded debris. Methodology: Thirty lower premolars with single roots and straight root canals were standardized at 17 mm. Then, they were inserted into Eppendorf tubes, and the 1.5% agar gel was introduced into the tubes surrounding the roots. The coronal section of the roots was kept visible. The set of tubes and agar gel was weighed 3 times and the average value was recorded. Then, the specimens were randomly distributed in 3 different groups according to the working length (CT) used for the instrumentation: Group (CT -1) - the working length 1 mm below the major foramen (MF); Group (CT 00) - the length was determined at the MF, and Group (CT +1) - the CT was determined 1 mm beyond the MF. Instrumentation was performed with Reciproc Blue R25 (VDW, Munich, Germany) under irrigation with 0.9% saline. After preparation, samples were removed from Eppendorf tubes and weighed 3 times again. The difference between the mean values ​​of the initial and final weight was recorded. The one-way ANOVA test (post-hoc Bonferroni) was used with P&gt; 0.05. Results: The average weight of the extruded waste was 0.0134 ± 0.0157 for CT -1, 0.0075 ± 0.0062 for CT 00 and 0.0075 ± 0.0068 for CT +1, with no statistically significant differences between groups. Conclusion: There was no impact of the different CTs on the amount of extruded debris beyond the apex.

A three dimensional finite element analysis of fiber post and dentin post in permanent maxillary central incisors: An in-vitro study

: Endodontically treated teeth are generally weakened as a result of loss of tooth structure due to decay, previous restorative procedures and endodontic access preparation. Ideal coronal reconstruction of endodontically treated tooth is still a challenge for restorative dentistry. Post and core system is a widely used method for treatment of structurally weakened teeth. Two extracted, caries-free maxillary central incisors with straight root canal were collected and mounted. Post space preparation were done and restored with fiber post and dentin post respectively. The model is simulated using the software “Creo” and this data is then transferred to software “Hypermesh” to create a Finite Element model i.e., a mesh of nodes and elements. This mesh is programmed to contain the material properties which defined how the structure will react to loading conditions at different angles. The Analysis is carried out using the Ansys software.: The FEA results showed that the Dentin post have better fracture resistance. The comparison between fiber and dentin posts exhibited a better stress resistance of dentin post over fiber post. Further research in this regard is required to support the findings of this study results.

Efficacy of Removing Thermafil and GuttaCore from Straight Root Canal Systems Using a Novel Non-Surgical Root Canal Re-Treatment System: A Micro-Computed Tomography Analysis.

The present study aims to evaluate the effectiveness of an XP-endo non-surgical root canal re-treatment system in removing both GuttaCore and Thermafil gutta-percha carrier-based root canal filling materials from straight root canal systems using micro-computed tomography (micro-CT) analysis. The study was performed on 20 single-rooted upper teeth, which were randomly allocated into the following study groups: Group A, Thermafil and AH Plus sealer (n = 10); Group B, GuttaCore and AH Plus sealer (n = 10). Before and after the non-surgical root canal re-treatment procedure, the samples were submitted for a micro-CT analysis. The volume of the root canal filling material (mm3), the volume of the remaining root canal filling material (mm3) and the time (minutes) needed to remove the root canal filling material were also recorded. Student’s t-test was used to analyze the results. No statistically significant differences were found between the volume of the remaining root canal filling material in the GuttaCore and Thermafil root canal filling systems at the coronal third (p = 0.782), middle third (p = 0.838) or apical third (p = 0.882) of the straight root canal systems; however, the GuttaCore required a statistically significant (p = 0.037) shorter amount of time (4.72 ± 0.76 min) to be removed than the Thermafil carrier-based root canal filling material (5.92 ± 1.42 min). The XP-endo Finisher non-surgical endodontic re-treatment system removes both GuttaCore and Thermafil gutta-percha carrier-based root canal filling materials from straight root canal systems, although removal of the GuttaCore gutta-percha carrier-based root canal filling material required less time.

Cutting efficiency of ProDesign R, Reciproc Blue and WaveOne Gold reciprocating instruments

This study aimed to evaluate, in vitro, the cutting efficiency and time spent for instrumentation of three different heat-treated reciprocating systems in simulated straight canals. Forty-five acrylic blocks with a straight simulated root canal with 21 millimeters in length were initially weighed (P1). After weighing the blocks were divided into three groups (n = 15) and each group prepared with the following systems: ProDesign R 25.06 (Bassi/Easy, Belo Horizonte, Brazil), Reciproc Blue25.08 (VDW, Munich, Germany) and Wave one Gold (Dentsply Sirona, Ballaigues, Switzerland). The time spent for the total preparation of each block was recorded. After instrumentation, they were subjected to final weighing (P2). The difference between P1 and P2 determined the amount of material removed (cutting efficiency) by each mechanized system. The statistical analysis was performed by the ANOVA test of each of the variables, for multiple comparisons of means the turkey test was used. As for preparation time, it can be seen that ProDesign R showed a longer preparation time (P &lt;0.5) compared to Reciproc Blue and Wave one Gold. Regarding cutting efficiency, there was no statistical difference between the groups (P&gt; 0.5). In straight simulated canals, the type of reciprocating instrument influences the time for instrumentation; however, it shows similar cutting efficiency.

The impact of different flow rate on apically extruded debris and irrigants

Aim: Root canal instrumentation might lead to extrusion of debris and irrigants, leading to postoperative pain and compromised outcomes. Several factors might impact extrusion during root canal instrumentation, including the flow rate in which the irrigant solution is applied inside the root canal. The aim of this study was to assess the extrusion of irrigants and debris with different flow rates of 0.9% saline solution. Matherials and Methods: Thirty mandibular premolars presenting single roots and straight root canals were used in this study. The roots were standardized in 17 mm and inserted in Eppendorf tubes. A 1.5% agar gel was placed inside the tube that involved the roots, while the coronal part of the roots was kept visible. The combination of tube and agar gel was weighted. Then, the specimens were randomly distributed to 3 different groups (n=10) according to the flow rate of the irrigation: Control Group (CG) 5 mL/min, High Flow rate Group (HG) 10 mL/min, and Ultra-High flow rate (UG) 60 mL/min. The canals were instrumented with a Reciproc Blue instrument size 25.08 up to the length of the root, following the manufacturer guidelines. After the instrumentation, the roots were removed and the tube and agar were weighted again. The difference between the final weight and the initial weight represented the total amount extruded beyond the apex. For statistical analysis, the ANOVA test (post-hoc Bonferroni) was used at P>0.05. Results: The mean weight of the extruded debris and irrigants for CG, HG, and UG was respectively 0.0079 ± 0.0087, 0.0110 ± 0.0093, and 0.0083 ± 0.0091. There were no statistically significant differences among the groups. Conclusions: Within the limitations of this study, it can be concluded that the flow rate of irrigants does not impact the extrusion of debris and irrigants.