WaveOne Gold Research Articles

Shaping ability of four single-file systems in the instrumentation of second mesiobuccal canals of three-dimensional printed maxillary first molars.

BackgroundThis study evaluated and compared the shaping ability of four advanced single-file nickel-titanium (NiTi) systems during the preparation of curved second mesiobuccal (MB2) canals in maxillary first molar replicas fabricated by three-dimensional (3D) printing via micro-computed tomography (Micro-CT) imaging.MethodsA total of 60 3D-printed maxillary first molar replicas were constructed from one extracted tooth, with an angle of curvature ranging from 15° to 25°. The MB2 canals from these 60 replicas were divided into 4 groups of 15 replicas according to the canal instrumentation system used, namely, Waveone gold (WOG), Reciproc blue (RCB), XP-endo shaper (XPS) and M3-L. The specimens were scanned before and after preparation using Micro-CT. The pre- and post-instrumentation images of each specimen were superimposed, and the amount of resin removed, the change in surface area, the canal transportation, and centering ability were assessed using the Mimics software. Instrumentation time was also recorded. One-way analysis of variance and least significant difference (LSD) tests were used to statistically compare the groups. The significance level was set at 5%.ResultsInstrumentation time with M3-L was significantly longer than the other systems (P<0.05). The amount of resin removed and the change in surface area generated by the 4 systems were different at the apical, middle, and coronal thirds, and the total canal (P<0.05). Overall, WOG and XPS resulted in the less change than RCB and M3-L. There was no significant difference among the groups at the middle third regarding canal transportation and centering ability (P>0.05). However, a significant difference was found at the apical level (P<0.05), where RCB showed the poorest centering ability and the highest canal transportation (P<0.05). In addition, XPS resulted in the least canal transportation (P<0.05) at the coronal level, while there was no significant difference between the four groups in terms of centering ability.ConclusionsThe M3-L instrument required more time to prepare the curved MB2 canals compared with the other systems. Overall, WOG and XPS showed the least resin removal and surface area change. M3-L, XPS, and WOG instruments respected the original canal curvature better than RCB files.

Alteration in surface roughness of reciprocating endodontic instruments

Background: Surface roughness is one of the most important characteristics of endodontic instruments, correlating to instrument fracture. The purpose of this study was to measure the surface roughness values of these instruments before and after resin root canal preparation without previous glide path preparation, with the new method. Data was obtained from field emission scanning electron microscopes (FE-SEM) combined with independent ImageJ software (NIH, Bethesda, MD, USA). Methods: A total of 20 simulated J-shape resin blocks with a radius of 4.5 mm, length of 16 mm, and angle of inflection of 600 were chosen and distributed into two equal groups. Each group was prepared by the WaveOne Gold Primary (Dentsply Sirona, Maillefer, Ballaigues, Switzerland) or the Reciproc Blue R25 (VDW, Munich, Germany) instruments, without glide path preparation. Special molds were used to confirm the same areas on the cutting blade at 3 mm and the instruments’ tips were scanned by FE-SEM, at different observed times. The parameters of Ra, Rq, and Rz in each sample were collected using the ImageJ software for analyses. The data was processed using the paired t-test with a significance level of 0.05. Results: Right after the first resin canal instrumentation, the surface roughness parameters of the two reciprocating investigated instruments were decreased. Conclusions: The FE-SEM images processed using the ImageJ software offered a trustworthy and suitable method for assessment of the NiTi endodontic file surface roughness.

Shaping ability of ProTaper Gold and WaveOne Gold nickel-titanium rotary instruments in simulated S-shaped root canals

Background/purposeGold metal technology improves flexibility and the resistance to cyclic fatigue of the endodontic mechanical files. This study compared the performance of ProTaper Gold (PTG) multiple file system and WaveOne Gold (WOG) single file system in simulated S-shaped root canals, which represents one of the most challenging root canal morphology. Materials and methodsForty S-shaped canals (n = 20 canals/per group) in resin blocks were instrumented to an apical size of 0.25 mm using PTG and WOG Primary, respectively. The total amount of resin removal, canal transportation, centering ratio, and the degree of canal straightening were measured in Photoshop CS6 software. Statistical analysis was performed by using Mann–Whitney U-test (α = .05). ResultsNone of the files fractured during the instrumentation. The WOG group removed significantly less amount of resin at 0, 3, 6, 7 and 9 mm from the apex (P < .05). The WOG group remained more centered in canals at 0 mm from the apex (P < .05). The PTG group showed a better centering ability and less canal transportation at 4, 5 and 6 mm from the apex (P < .05). In the coronal curvature portion, the use of WOG Primary significantly decreased curvature angle and increased radius compared with PTG instruments (P < .05). There was no significant difference between the two groups in terms of the apical curvature angle and radius change (P > .05). ConclusionThe WOG Primary file has a less aggressive dentin cutting and more centered apical preparation. The PTG system is more advantageous in shaping the coronal curvature of S-shaped canal.

The effect of two rotary and two reciprocating NiTi systems on postoperative pain after root canal retreatment on single-rooted incisor teeth: A randomized controlled trial.

This randomized clinical trial aimed to assess the effect of two rotary (ProTaper Retreatment + ProTaper Gold and Hyflex EDM) and two reciprocating (Reciproc Blue and WaveOne Gold) NiTi systems on postoperative pain after root canal retreatment on single-rooted incisor teeth. One hundred and eighty patients scheduled for root canal retreatment were randomly assigned to one of the four groups according to the NiTi system (ProTaper Retreatment + ProTaper Gold, Hyflex EDM, Reciproc Blue or WaveOne Gold) used for the removal of root canal fillings and further canal preparation. The working length was determined to be 1mm shorter than the '0.0' mark of the apex locator. Root canals were filled with gutta-percha and an epoxy resin-based root canal sealer using a lateral compaction technique. The teeth were restored using a resin composite material. A single operator performed the retreatments in a single visit. The incidence and intensity of postoperative pain were rated on a numeric rating scale by patients 24, 48 and 72h after retreatment. The number of analgesic tablets (400mg Ibuprofen) taken by patients was also recorded. Data were analysed using the Mann-Whitney U, Wilcoxon and chi-square tests. For the intensity of postoperative pain, the difference between the four groups was not significantly different (p>.05). No significant difference was found between the groups in terms of analgesic medication intake (p>.05). The rotary and reciprocating NiTi systems tested in this study were associated with similar intensity of postoperative pain and intake of analgesics following root canal retreatment on single-rooted incisor teeth completed in one visit.

Evaluation of the Shaping Ability of Three Thermally Treated Nickel–Titanium Endodontic Instruments on Standardized 3D-printed Dental Replicas Using Cone-Beam Computed Tomography

Background and Objectives: The aim of the present study is to compare the efficacy of three root canal preparation systems in the shaping of 3D-printed root canal replicas of single rooted teeth. Materials and Methods: Sixty 3D-printed root canal replicas were produced and divided into three groups, each consisting of twenty samples. Each group was shaped with a different instrument: Reciproc Blue R25/08 (VDW GmbH, Munich, Gemany), WaveOne Gold Primary 25/07 (Dentsply Sirona, Ballaigues, Switzerland), and ProTaper Gold F2 25/08 (Denstply Sirona). To ensure the reproducibility of pre- and post-operative CBCT images of the root canals, the endodontic printed replicas were placed in a mould of silicon impression material. A cone-beam computed tomography (CBCT) software was used to compare pre- and post-instrumentation images collected at three levels of the root canal length: 3, 6, and 9 mm from the apical foramen. The amount of transportation, centring ability, and curvature angle after shaping were evaluated for each system. The results were statistically analysed and compared using one-way analysis of variance (ANOVA). Results: Regarding the transportation of the root canal after shaping, significant differences between groups at 3 mm (p = 0.010721) and 6 mm (p = 0.000046) were recorded in the mesio-distal direction, while in the bucco-lingual significant differences were only observed at 6 mm (p = 0.000554). Reciproc Blue removed more dentin from the mesial and buccal wall of the root canal. When evaluating the centring ability of the three systems, significant differences were observed between the groups at the level of 9 mm (p = 0.037258) in the mesio-distal direction, and at the level of 6 mm (p = 0.038197) in the bucco-lingual direction. Significant differences of the canal curvature angle after shaping were also observed between groups (p = 0.000001). Reciproc Blue straightened the curvature the most, while ProTaper Gold the least. Conclusions: All systems produced minor root canal transportation. No instrument was able to achieve a perfect centring preparation of the root canal. All systems produced a small degree of root canal straightening.

Cleaning of long oval canals with WaveOne Gold system associated with different irrigant agitation protocols

Aim: The aim of the study was to evaluate the cleaning of mandibular incisors with WaveOne Gold® (WO) under different preparation techniques. Methods: A total of 210 human mandibular incisors were selected and divided into seven groups (n = 30), prepared by WO single-files (Small 20/.07 – WOS; Primary 25/.07 – WOP; Medium 35/.06 – WOM; or Large 45/.05 - WOL) and sequential-file techniques (WOS to WOP; WOS to WOM; and WOS to WOL). Further subdivision was made according to irrigation protocol: control group (manual irrigation - CON), E1 Irrisonic® - EIR, and EDDY® - EDD. Debris removal and the smear layer were evaluated by scanning electron microscopy. Data were analyzed by using Spearman’s correlation test. The significance level was set at 5%. Results: For debris and smear layer removal, WOS and WOP, EIR differed from CON and EDD (p &lt;0.05). Conclusion: Regardless of the instrumentation used, the agitation of the irrigant solution provided better cleanability. These findings reinforce the need for agitation techniques as adjuvants in cleaning root canal systems in mandibular incisors.

Cyclic fatigue resistance of four different nickel-titanium instruments in an artificial canal

Introduction: The objective of this study was to measure the number of cycles to fracture of four continuous or reciprocating rotary nickel-titanium instruments in different materials. Methods: A total of 40 nickel-titanium instruments were used for the present study. Instruments were divided into four groups (n=10): group 1, Revo-S SU; group 2, ProTaper Next X2; group 3, Reciproc R25; group 4, WaveOne Gold Primary. An artificial stainless-steel was used to test the cyclic fatigue of the instruments. The instruments were introduced into the stainless-steel canal, one at a time, until they reached the other end, then they were rotated inside the canal without in-out motion. The time from the beginning of instrument rotation until the occurrence of breakage was recorded. The number of rotated cycles to fracture of the instrument were calculated based on the revolutions per minute (rpm) of each instrument and the recorded rotated time. The mean number of cycles to fracture and standard deviations were calculated and statistically analysed. Results: The number of cycles to fracture of the Revo-S SU was the lowest, and that of the WaveOne Gold Primary was highest. Scanning electronic microscope images of fracture surfaces revealed the characteristics of fatigue. Conclusions: The number of cycles to fracture of the reciprocating WaveOne Gold Primary system was the highest amongst the tested instruments.

Evaluation of preparation times of WaveOne Gold reciprocating instruments compared to two analogous counterparts

Manufacturers are constantly developing new products to optimise endodontic treatment. These newer file systems are often associated with increasing expenditure of instrumentation and can affect the cost effectiveness of root canal treatment. Recently, companies have emerged that claim to have successfully reproduced many of the more established endodontic file systems manufactured by Dentsply Sirona (Ballaigues, Switzerland). EdgeEndo (Albuquerque, New Mexico, USA) and PacDent (Brea, CA, USA), which manufacture files similar in design to that of Dentsply Sirona, claim that they are similar and sell them at a lower price. A performance comparison of the replica file systems to their original is of clinical importance. The aim of this ex vivo study was to compare the total glide path and canal preparation times of WaveOne Gold Glider (Dentsply Sirona) combined with the Primary WaveOne Gold (Dentsply Sirona), Edge GlidePath (Edge Endo, Albuquerque, New Mexico, USA) followed by the Primary EdgeOne Fire (EdgeEndo); and One File G Glide Path (Pac-Dent, Brea, CA, USA) file combined with the Primary One File G (Pac-Dent) Shaping file. Sixty curved untreated canals of extracted, human, mandibular molars were randomly divided into three groups of 20 canals each for mechanical glide path enlargement and root canal shaping. Group 1 (WaveOne Gold Glider + Primary WaveOne Gold); Group 2 (Edge GlidePath + Primary EdgeOne Fire); and Group 3 (One File G Reciprocating Glide Path File + Primary One File G Reciprocating shaping file). The total time taken to prepare a glide path and to complete the root canal preparation of each canal was recorded (in seconds) by means of an iPhone stopwatch (Apple Inc., Cupertino, California). The time taken to change files was not recorded. Throughout the instrumentation process, RC Prep was used as a lubricant, and5 mL 3% sodium hypochlorite was used as irrigation solution. Mean and standard deviations were determined for each group, and analysis of variance was used to statistically compare the mean glide path preparation times for the three groups. The fastest final canal preparation time was achieved by WOGG/PWOG (41.78 ± 10.58 s), followed by OFGP/ POFS (42.02 ± 12.16 s) and then EGP/PEOF (42.49 ± 10.44 s). There were no statistically significant differences between the canal preparation times of the three combination groups (p&gt;0.05).

Effect of Reciprocating versus Rotary Instrumentation on Post-endodontic Pain and Endotoxins Level in Infected Root Canals: A Randomised Clinical Trial

Background: This randomised, prospective, controlled trial aimed to assess the effect of reciprocatingsingle-file and rotary instrumentation on the intensity of postoperative pain and the amount of endotoxins inprimarily infected root canals.Methodology: Forty participants were randomly assigned into two equal groups according to root canalinstrumentation technique (n = 20), control group: root canals were instrumented using ProTaper Next rotarysystem and intervention group: canals were instrumented using WaveOne Gold reciprocating instrumentationsystem. Root canal treatment was carried out on two visits and postoperative pain of participants wasmeasured using a numerical rating scale (NRS) at predetermined time intervals 6, 12, 24, 48 hours afterinstrumentation and obturation appointments. Quantification of endotoxins was done using the Sandwich-ELISA method at predetermined time intervals (after access cavity preparation and after completion ofinstrumentation). Pain score data were summarised as mean and standard deviation.Results: No statistically significant difference was noted between the single-file reciprocating system(WaveOne Gold) and the multiple-file rotary system (ProTaper Next) regarding postoperative pain andreduction in the amount of endotoxins (P &gt; 0.05).Conclusion: Both single-file reciprocating instruments and multi-file rotary instruments resulted in mild tomoderate postoperative pain and comparable reduction of endotoxins level.

A Comparison of Cone Beam Computed Tomography and Periapical Digital Radiography for Evaluation of Root Canal Preparation

The aim of the present study is to compare cone beam computed tomography and periapical digital radiography for the evaluation of root canal preparation. Nine extracted human molars were used in this study. Following access cavity preparation, mesio-buccal roots of maxillary and mesial roots of mandibular molars were prepared and the remaining roots were cut off. Three amalgam cavities were prepared on the coronal part of the teeth and were filled with amalgam to be used as landmarks. Specimens were scanned using cone-beam computed tomography and periapical digital radiograph images were obtained before and after root canal preparation. WaveOne Gold Primary was used for root canal preparation to full working length. Specimens were then scanned using CBCT and a periapical radiograph for the after-instrumentation images. The transportation and centering ratio were measured and calculated on the CBCT and periapical radiographic images. The Bland–Altman method was used for detecting the bias in the evaluation of agreement between the two methods’ measurements. There was agreement between the two methods’ measurements using CBCT scans and periapical digital radiographic images in the evaluation of transportation and centering ratio parameters. The two methods could be used interchangeably in measurements of transportation and calculating the centering ratio.

Effects of Root Canal Curvature and Mechanical Properties of Nickel-Titanium Files on Torque Generation

IntroductionThis study aimed to compare the torque generated by 4 different files in root canals with 4 different curvature angles. MethodsFour brands of nickel-titanium (NiTi) endodontic files were selected: WaveOne Primary (Dentsply Sirona, Ballaigues, Switzerland), WaveOne Gold Primary (Dentsply Sirona), ProTaper Universal F2 (Dentsply Sirona), and ProTaper Next X2 (Dentsply Sirona). A tempered steel block containing artificial canals with 4 different canal curvatures (15°, 25°, 35°, and 45°) was constructed. Each file was used according to the manufacturer’s instructions in the dynamic model, with an added 15 axial up-and-down movements of 4 mm at the end of the canal. The generated torque was recorded, and the total and maximum torque values were measured. Two-way analysis of variance and the Duncan post hoc comparison test were performed at a significance level of 95%. ResultsA significant correlation between the curvature angle and the type of file system was observed (P < .05). As the degree of canal curvature increased, the generated total and maximum torque increased. At 15° and 25°, the NiTi files with reciprocating motion generated a higher total and maximum torque than files with continuous rotation. ProTaper Universal of conventional NiTi alloy showed the steepest increase in the generated total and maximum torque with the increasing curvature angle. The ProTaper Next file had the lowest torque values at the higher canal angles of 35° and 45° (P < .05). ConclusionsDespite the study limitations, it can be concluded that root canal curvature, design, and heat treatment of NiTi files and file kinematics affect the generated torque during instrumentation.

A comparison of failure rates and canal preparation times between WaveOne Gold and One Curve file systems with and without glide path preparation in simulated canals

The aim of this study was to compare the failure rate and canal preparation times of the Primary WaveOne Gold file (Dentsply Sirona, Ballaigues, Switzerland) with the One Curve file (Micro Méga, Besançon, France). The influence of glide path preparation on failure rate and final preparation times were also evaluated. Endo training blocks (Dentsply Sirona) with simulated canals were separated into four groups: Group 1: Primary WaveOne Gold with WaveOne Gold Glider; Group 2: Primary WaveOne Gold without glide path; Group 3: One Curve with One G; Group 4: One Curve without glide path. The number of training blocks that were shaped before instrument fracture occurred was recorded. Glide path and final preparation times were also recorded. Where no glide path was prepared, One Curve file prepared a significantly higher number of canals (14.33± 0.58) than the Primary WaveOne Gold (4.6 ± 1.34) before instrument fracture occurred (p&lt;0.001). The One Curve with One G Glide Path file prepared significantly higher number of simulated canals (28±1.41) than the Primary WaveOne Gold with WaveOne Gold Glider (15 ± 1.41) before instrument fracture (p&lt;0.001). Glide path preparation times with WaveOne Gold Glider (4.8s) were significantly faster compared to the One G Glide Path file (7.29s)(p&lt;0 .001). Significantly faster final canal preparation times were achieved in groups where glide path were prepared (p&lt;0.001). One Curve files exhibits a greater fracture resistance than Primary WaveOne Gold files. Glide path preparation increases the longevity of preparation files and results in faster final canal preparation.

Micro-CT evaluation of rotary and reciprocating glide path and shaping systems outcomes in maxillary molar curved canals

The shaping outcomes after instrumentation with rotary and reciprocating glide path and shaping systems were evaluated through micro-computed tomography (Micro-CT). Thirty extracted maxillary first molars were selected. Mesio-buccal canals were randomized into two groups (n = 15): rotary system ProGlider and ProTaper Next X1, X2 (PG-PTN) and reciprocating system WaveOne Gold Glider and WaveOne Gold Primary (WOGG-WOG). Specimens were micro-CT scanned before, after glide path and after shaping. Increase in canal volume and surface area, percentage of removed dentin from the inner curvature, centroid shift and canal geometry variation through ratio of diameter ratios (RDR) and ratio of cross-sectional areas (RA) were measured in the apical and coronal levels and at the point of maximum curvature. The number of pecking motions needed to reach the working length (WL) was recorded. One-way ANOVA and post hoc Turkey–Kramer tests were used (p < 0.05). Post-glide path analysis revealed that in the coronal third, RDR was more favorable to PG and centroid shift was lower for WOGG in the apical third. Post-shaping analysis showed a reduced removal of dentin and a more favorable RA for PTN at point of maximum curvature. The number of pecking motions up to WL resulted in different between groups both for glide path and shaping phases. Despite a higher dentin removal for reciprocating instruments at the point of maximum curvature, both systems seemed to produce well-centered glide path and shaping outcomes. Rotary and reciprocating systems seemed able to respect the original canal anatomy.

Postoperative Pain after Use of the WaveOne Gold and XP-endo Shaper Systems: A Randomized Clinical Trial

IntroductionThe present study aimed to clinically compare the incidence of postoperative pain after endodontic treatment of posterior teeth using the WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland) and XP-endo Shaper (XPES; FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems. MethodsIn a single-blind randomized clinical trial, 148 vital teeth with an indication for conventional endodontic therapy for prosthetic purposes were treated by 5 specialists following a preestablished protocol. All participants were unaware of the treatment they received. The teeth were randomly divided into 2 groups (n = 74) according to the instrumentation system used (the WOG group and XPES group). The treatments were performed in a single session. The participants were asked to rate the intensity of postoperative pain on a visual analog scale (no pain, mild pain, moderate pain, and severe pain) after 24, 48, and 72 hours and 7 days. ResultsThe incidence of postoperative pain was higher in the XPES group after 24, 48, and 72 hours compared with those in the WOG group (P < .05). Two participants in the WOG group experienced severe postoperative pain after 24 hours. None of the participants in either group reported pain after 7 days (P > .05, Mann-Whitney test). ConclusionsPostoperative pain is expected after preparation of the root canal system with the WOG and XPES systems tested, but it only persists for a short period. Although more common after the use of the XPES system, the pain was classified as mild at all time points.

Influence of different reciprocating systems on the apical extrusion of debris in flat-oval canals

Aim: To evaluate the apical extrusion of debris in flat-oval canals, using three reciprocating systems at two different working lengths (WL), 0 mm and 1 mm from the apical foramen. Methods: Ninety mandibular incisors were randomly divided into three groups based on the systems: WaveOne Gold #25.07 (WOG), ProDesign R #25.06 (PDR), and X1 Blue #25.06 (X1B). Extruded debris were collected and dried in pre-weighed Eppendorf tubes. Three consecutive weighings were performed for each tube, and the mean was calculated. If the assumptions of normality and homogeneity of variance were not met, the Kruskal-Wallis test was used to analyze the amount of extruded debris between groups with the same WL, and the Mann-Whitney U test was used for comparison within groups for each WL. Results: All groups had extruded debris, with higher median values occurring at 1 mm. No significant difference regarding the amount of debris extrusion was observed at 0 mm (p&gt;0.05) and 1 mm (p&gt;0.05) between groups. However, within the groups, at different WL, there was greater extrusion at 1 mm (p&lt;0.05), with PDR differing significantly from the other systems (p&lt;0.05). Conclusion: The extrusion of debris occurred regardless of the group, with higher values at 1 mm. However, using PDR at 1 mm from the apical foramen showed the highest values of extrusion.

The effect of Erbium-doped Yttrium Aluminum Garnet laser irradiation on push-out bond strength of endodontic sealers with root canal dentin: An in vitro evaluation of push-out bond strength and failure modes

Objectives: The aim of this study was to evaluate and compare the push-out bond strength of bioceramic sealer and resin-based sealer on Erbium-doped Yttrium Aluminum Garnet (Er:YAG) treated root canals. Material and Methods: Sixty single-rooted teeth were collected, decoronated apical to the cementoenamel junction, maintaining the minimum root length of 14 mm. Samples were instrumented with WaveOne Gold primary file and divided into two experimental groups (n = 30), based on laser irradiation: Group I: No laser and Group II: Er:YAG laser irradiated. Groups I and II were again divided into two subgroups “a” (AH Plus) and “b” (mineral trioxide aggregate [MTA] Fillapex) with 15 samples in each group. As per the grouping, sealers were coated onto the canal walls and obturated. After 24 h of storage in 100% humidity at 37°C, all the samples were sectioned transversely and push-out test was performed using universal testing machine. Stereomicroscope was used to determine the mode of failure. A one-way analysis of variance was employed to compare the mean POBS. Kolmogorov–Smirnov and Shapiro–Wilk parametric tests were done to check the normality. The Games-Howell multiple post hoc test was used for pairwise comparison of the groups at a 95% confidence level. Results: Both AH Plus and MTA Fillapex exhibited higher bond strength in the laser-treated canals. AH plus exhibited superior bond strength compared to MTA Fillapex in both laser and non-laser-treated groups (P &lt; 0.05). AH Plus groups have predominantly presented cohesive failure whereas MTA Fillapex presented mixed failures. Conclusion: Irradiation with Er:YAG laser in the root canal before obturation improves the bond strength significantly. The adhesive properties of MTA Fillapex are comparable to that of AH Plus.

Comparison of Postobturation Pain Experience after Apical Extrusion of Calcium Silicate– and Resin–Based Root Canal Sealers

IntroductionThis study compared the intensity of postobturation pain after unintentional apical extrusion of calcium silicate–based root canal sealers (EndoSequence BC Sealer [Brasseler USA, Savannah, GA] and Bio-C Sealer [Angelus, Londrina, PR, Brazil]) with a resin-based sealer (AH Plus; Dentsply Sirona, York, PA). MethodsA total of 330 patients referred for root canal treatment on molar teeth with asymptomatic irreversible pulpitis were recruited. Root canals were prepared using WaveOne Gold instruments (Dentsply Sirona) in a crown-down technique and irrigated with 2% chlorhexidine gel and saline solution. Next, patients were randomly distributed into 3 groups according to the root canal sealer used (n = 110): AH Plus, BC Sealer, and Bio-C Sealer. Root canal filling was then accomplished with a vertical compaction technique. Patients presenting with an unintentional extrusion of sealers (n = 13/group) were assessed for postobturation pain experience using a visual descriptor scale ranging from 0–10 at 6-, 12-, 24-, and 48-hour and 1-week intervals after treatment. Mixed analysis of variance repeated measures were used to assess the results (α = 0.05). ResultsThe extrusion rate was similar for all sealers (~12%). There was no significant difference in the postobturation pain results between the root canal sealers evaluated (P > .05). However, after the time interval of 12 hours, AH Plus (P = .04073) and Bio-C Sealer (P = .04327) demonstrated a significant reduction in pain, whereas BC Sealer did not show differences in pain intensity, even in the maximum period evaluated of 1 week (P > .05). ConclusionsThe occurrence of unintentional apical extrusion of calcium silicate–based root canal sealers presents similar postoperative pain results compared with resin-based sealers with low-intensity pain.

Micro-CT evaluation of 'danger zone' and microcrack formation in mesial root canals of primary teeth with single-file rotary and reciprocating systems.

Although single-file rotary systems are accepted in the field of paediatric dentistry in terms of providing time advantage, research works continue due to the variable anatomical structure of the root canal. This study aimed to evaluate rotary systems in different kinematics in terms of microcracks and the shaping of the danger zone in primary molars by micro-CT. The mesial canals of primary molars (n=30) were used. Root canals in each group (n=10) were prepared with single-file rotary systems (One Shape®, OS; XP-endo® Shaper, XP-ES; WaveOne Gold, WOG). The images were evaluated for dentin thickness in the danger zone and microcrack formation. WOG caused the highest dentin reduction in the danger zone area. OS led to significantly less dentin reduction than XP-ES and WOG (P<.05). The XP-ES showed the highest number of microcracks (P<.05). No statistically significant difference was found between WOG and OS (P>.05). In all systems, more microcracks were observed in the middle third than coronal and apical. Within the limitations of this study, the rotary systems were superior to reciprocating in terms of shaping ability in the danger zone. It is thought that further studies with different systems should be designed considering the anatomical variations and chemical composition of primary teeth.

Management of apical periodontitis using WaveOne gold reciprocating files, single-cone endodontic approach: A case series

IntroductionThe endodontic treatment of apical periodontitis (AP) without surgical intervention presents a unique clinical challenge. This case series aimed to test the changes in size of periapical lesion scale and healing in post-treatment of AP by cone beam computed tomography (CBCT) using Waveobe Gold reciprocating file with single cone treatment approach. Presentation of casesA total of 20 patients with 20 teeth (9 M, six premolars, one canine, and four incisors) with AP underwent CBCT scanning before and after non-surgical root canal treatment (NSRCT) or non-surgical retreatment (NSReTx). Standardized root canal chemo-debridement and instrumentation with WaveOne Gold (WOG) reciprocating files was used. The canals were obturated using epoxy-based sealer (AH Plus) with a single WaveOne Gold conform fit gutta-percha cone technique. After one year, assessment with CBCT images showed that the success and healing rate using (AH Plus) with single cone technique was very high. DiscussionApical periodontitis is an inflammatory disease at the root end of teeth. Following NSRCT or NSReTx, evaluation of lesion size by radiograph has been essential to the evaluation of lesions post-operatively. In addition to the absence of symptoms, complete restitution of the lamina dura and periodontal ligament (PDL) space on post-operative radiograph has been considered the optimal outcome success. ConclusionsWithin the limitations of this study, NSRCT or NSReTx using reciprocating WaveOne Gold and single cone with AH plus sealer resulted in healing of AP as assessed by CBCT.

Percentage of Gutta-percha filled area in canals shaped with Nickel-Titanium instruments and obturated with GuttaCore and Conform Fit gutta-percha cones

Aim: The purpose of this study is to compare continuous wave with conform fit gutta-percha point and the core-carrier system with GuttaCore assessing the percentage of gutta-percha filled areas (PGFA), sealer filled areas (PSFA) and voids (PVA) in extracted teeth. Methodology: Seventy-five extracted single rooted premolars were assigned to 5 groups, groups A and C were shaped with WaveOne Gold medium, groups B and D with ProTaper Next X3, and group E with manual instruments #35 K-file. Obturations were managed with GuttaCore in groups A and C; with Conform fit gutta-percha points in groups B and D; and with ISO-sized 35 gutta-percha master cones and cold lateral compaction technique in group E. The teeth were sectioned at 2, 4, 6, and 8 mm from the apex and for every section the percentages of gutta-percha and sealer filled, and void areas with respect to the total area were calculated. Data obtained were analysed for each variable at each level by using a one-way ANOVA with group as dependent variable (α=0.05). Multiple comparisons between the five experimental groups were conducted by using the Student’s t-test with Sidak alpha correction. Results: At all levels group E produced significantly less PGFA and higher PSFA and PVA than all the other experimental groups. At 2 mm from the apex, group A showed significantly higher PGFA than group C and a significantly lower PSFA than C and D. At 4 mm from the apex groups A and B produced significantly better results in terms of PGFA than groups C and D. The PSFA and PVA were significantly lower in group D with respect to groups A and B. PVA were statistically significant lower in group C than in group B. At 8 mm from the apex group A showed significantly higher PGFA than groups B and D, a significantly lower PSFA and PVA than group B. Conclusions: Independently of the instrument used for preparation (WaveOne gold versus ProTaper Next) Conform Fit point and GuttaCore produced very homogeneous obturations with high PGFA. The association of WaveOne Gold file system shaping and the GuttaCore obturation technique produced better results in terms of PGFA, PSFA and PVA than all the other techniques especially in the apical portion of the root canals. Manual instrumentation and the cold lateral obturation technique yield poor quality root canal obturations.