Quality of Root Filling after Obturation with Gutta-percha and 3 Different Sealers of Minimally Instrumented Root canals of the Maxillary First Molar

Clinical outcome of non-surgical root canal treatment using different sealers and techniques of obturation in 237 patients: A retrospective study

OBJECTIVES

The aim of this retrospective study was to compare the clinical results of two root canal sealers and three obturation techniques used for non-surgical root canal treatment.

MATERIALS AND METHODS

A total of two hundred eighty-three root canal treated teeth in two hundred thirty-seven patients with minimum a 6-month follow-up was included for this study. The canals were filled with three different modes: 1) cold lateral condensation (CLC) and AH Plus Sealer; 2) continuous wave condensation technique (CWC) and AH Plus Sealer, and 3) sealer-based obturation technique (SBO) and AH Plus Bioceramic Sealer. The treatment outcome was analysed based on clinical signs and symptoms, and periapical radiograph (periapical index, PAI).

RESULTS

There were no significant differences in treatment outcome between various sealers and filling techniques applied. The sealer extrusion was found most frequently in the CWC group (60.67%), followed by SBO (59.21%) and CLC (21.19%) with statistically significant differences (p < .05). The initial diagnosis, previous treatment and sealer extrusion (p < .05) were prognostic factors that affected treatment outcome.

CONCLUSIONS

Based on the findings of this study, neither the sealer type nor the filling technique affected the treatment success while preoperative diagnosis, previous treatment and sealer extrusion had significant effect on the outcome.

CLINICAL RELEVANCE

A bioceramic sealant applied along with the single-cone technique might be considered as an alternative method in root canal obturation.

Penetration of Calcium Silicate and Epoxy Resin Sealers Into the Lateral Canals

OBJECTIVES

The aim of this research was to compare the penetration ability of calcium silicate-based sealers (iRoot SP and TotalFill BC HiFlow) and an epoxy resin-based sealer (AH Plus) into the lateral canals using the single-cone (SC) or continuous wave compaction (CW) obturation techniques.

METHODS

Ninety single-rooted human teeth received canal instrumentation and diaphanisation before artificial lateral canals were created at 3 different root levels. The specimens were randomly allocated into 6 groups based on the combination of obturation technique and sealer used. Radiographic and photographic measurements evaluated the percentage of sealer penetration. Statistical analysis was performed to compare the penetration ability amongst different types of sealers, obturation methods, and root levels.

RESULTS

Although TotalFill BC HiFlow sealer combined with the CW technique demonstrated greater sealer penetration at the coronal level (P < .05), the overall penetration ability of iRoot SP, TotalFill BC HiFlow, and AH Plus was not significantly different. The deepest sealer penetration was observed at the apical root level.

CONCLUSIONS

All sealers showed similar penetration abilities into the lateral canals using the SC or CW techniques in vitro. Calcium silicate-based sealers have comparable penetration ability into lateral canals compared to epoxy resin-based sealers using SC or CW obturation techniques.

Quality of different obturation techniques to fill perforating internal root resorption: a micro-computed tomographic study

BACKGROUND

This study aimed to assess the quality of various obturation techniques to fill perforation caused by internal root resorption using Micro-computed Tomography.

METHODS

Cone-beam computed tomography images of a maxillary central incisor tooth with perforating internal resorptive defect were used to create a 3D printed model of the affected tooth. The replicas were divided into four groups based on the obturation technique used. The techniques included Group 1: a polydimethylsiloxane-based sealer (GuttaFlow-2) with gutta-percha. Group 2: same as Group 1 except for using a pre-mixed Bioceramic-based sealer (NeoSEALER Flo). Group 3: the defect was filled entirely using the NeoSealer Flo Bioceramic-based sealer. Group 4: the samples were obturated using the warm vertical compaction technique with a resin-based sealer (ADSeal). The resin models were then scanned a micro-computed scanner to evaluate the percentage of voids in each group.

RESULTS

The results showed that NeoSEALER Flo groups had significantly the highest volume of voids while GuttaFlow-2 and warm vertical compaction groups had the lowest void volume.

CONCLUSIONS

GuttaFlow-2 and warm vertical compaction techniques performed best in filling the internal resorptive defect.

Comparative evaluation of push-out bond strength and mode of failure of three different obturating materials: An in vitro study

Aim

This research aimed to assess the push-out bond strength (PBS) to dentin of three distinct obturation materials inside the root canal and identify the failure mechanism.

Materials and Methods

The research used 30 undamaged human mandibular premolars. The specimens were randomly assigned to three groups, each employing a different sealer (n = 10). Group 1 used AH Plus sealer, Group 2 used GuttaFlow-2 sealer, and Group 3 used bioceramic sealer (CeraSeal). The obturation procedure was performed utilizing the single-cone method with gutta-percha. The specimens were divided into sections and loaded using a universal testing machine. Following PBS testing, every sample underwent a stereomicroscope examination, and the specific failure mechanism was documented.

Results

The average PBS was greatest for AH Plus, followed by CeraSeal and Guttaflow-2. Notable disparities existed between the coronal and apical levels.

Conclusion

AH Plus exhibited superior PBS qualities to root dentin compared to other sealers.

Thermal and volumetric assessment of endodontic filling techniques using infrared thermography and micro-CT

PURPOSE

To assess root temperature during filling techniques and quantify the volume of endodontic filling materials using infrared thermography (IT) and micro-computed tomography (micro-CT).

METHODS

Ninety premolars were divided into three groups: lateral condensation (LC), single cone (SC) and thermomechanical compaction (TMC). For thermal analysis, 45 teeth were assessed using a FLIR T650sc IT camera during filling techniques and 45 teeth were scanned using a Nikon micro-CT to assess gutta-percha, cement, and void volumes. Descriptive and inferential statistical analyses were performed (non-parametric Mann-Whitney test, Kruskal-Wallis test, and Friedman test with Tukey's bidirectional analysis of variance).

RESULTS

TMC showed the highest temperature increase at 15 s after the procedure and a significant temperature decrease at 45 s after its completion. TMC showed the largest volume of gutta-percha and LC the highest void volume.

CONCLUSION

The temperature increase generated by gutta-percha endodontic filling techniques is within acceptable limits. A greater volume of endodontic cement was observed for the SL and LC filling techniques.

Comparison of Two Root Canal Filling Techniques: Obturation with Guttacore Carrier Based System and Obturation with Guttaflow2 Fluid Gutta-Percha

Introduction: The aim of the present study was to compare the quality of the root canal obturation obtained with two different techniques, i.e., thermoplastic gutta-percha introduced through a carrier (GuttaCore) and fluid gutta-percha (GuttaFlow2). Materials and Methods: The study included 40 permanent single-rooted human teeth, divided into two groups and obturated with Guttaflow (group G) and with GuttaCore (group T). The teeth were fixed and transversely sectioned, they were examined by scanning electron microscopy. The dentin–cement–gutta–percha interface and the percentage of voids produced by the two techniques were statistically analyzed. Results: GuttaCore showed a better filling in the apical third of the canal with a percentage of voids equal to 5%. GuttaFlow showed a lower percentage of voids in the middle and coronal thirds of the canal, 1.6% of coronal voids. Statistical analysis showed a statistically significant difference in the percentage of voids in the two groups (GuttaCore and Guttaflow2) in each portion. Conclusions: GuttaFlow2 seems to flow optimally in the middle and coronal third of the canal, with greater difficulty in filling the apical third. Due to the rigidity of the carrier, GuttaCore is able to reach better the most apical portions of the canals, with greater difficulty in creating the three-dimensional seal at the level of the middle third and coronal third.

A critical analysis of research methods and experimental models to study root canal fillings

Canal filling materials and techniques have been one of the most studied topics in Endodontics. A simple search using the mesh term "root canal filling" in PubMed revealed more than 11,000 articles, an impressive number that is much higher than "root canal disinfection" (5,544 articles) or even the popular "root canal preparation" (8,527 articles). The overriding importance attributed to root filling procedures is not merely intuitive. It derived from the appealing relevance given by the appearance of the white lines in common radiographs grounded on retrospective clinical data that had identified the quality of a root filling as one of the major causes of treatment failure (lack of healing). Since the publication of the Washington study, impressive efforts have been made for the release of new materials and techniques, as well as, for the development of a plethora of laboratory methods to assess the quality of root filling procedures. This narrative review aims to address and discuss the most relevant laboratory methods to assess the root canal filling. Since filling quality improvements have not translated into higher success rates, as reported in longitudinal clinical studies, more than to deliver a simple methodology-based review, this paper aims to present an in-depth critical view on the assessment of laboratory methods used to study the filling materials and techniques. Recent data indicate that the long-term dimensional stability/degradation over time of endodontic sealers plays a central role in the treatment outcome. In this context, laboratory methods should be developed focusing on predicting, at least to some degree, the long-term clinical behaviour of root canal fillings, rather than simply ranking different materials or techniques.

Retreatment of Experimental Carrier-Based Obturators with the Remover NiTi Instrument: Evaluation of Apical Extrusion and Effects of New Kinematics

The objective of this study is to evaluate the retreatment time and weight of apically extruded debris yielded by two different kinematics during the removal of different root canal filling materials. Forty straight single-rooted extracted teeth were instrumented with HyFlex CM files and obturated with two different techniques: 25.04 HyFlex experimental carrier-based obturators (Coltène/Whaledent, Altstätten, Switzerland) (group 1) or 25.04 single gutta-percha cones (Roeko Coltène/Whaledent, Altstätten, Switzerland) (group 2) and Guttaflow Bioseal as the sealer. Samples were divided into four subgroups (n = 10) according to the used kinematics for the removal of root canal filling materials: continuous rotation (A) or retreatment motion (B) with a Remover and HyFlex EDM Nickel-Titanium instruments activated with a CanalPro Jeni micromotor (Coltène/Whaledent, Altstätten, Switzerland). Time for retreatment was digitally recorded, and debris extruded from the apex was collected in Eppendorf tubes and weighted with an analytical balance. Data on retreatment time and apical extrusion were statistically analyzed with the Kruskal–Wallis test (p < 0.05). Working length was achieved in all the retreated samples. The removal of root filling material resulted significantly faster with the Jeni mode (p < 0.001), and the difference was significant for the removal of both filling materials (p < 0.05). No significant differences on debris extrusion between single cone and experimental obturators groups were noted (p > 0.05), and no significant differences between kinematics (continuous rotation vs. Jeni motion) were observed (p > 0.05). All the tested retreatment strategies lead to an extrusion of material from the apex, and the weight of apically extruded debris was similar. The use of the innovative CanalPro Jeni kinematics accelerates the time for the removal of root filling materials.

Comparison of Root Filling Quality of Two Types of Single Cone-Based Canal Filling Methods in Complex Root Canal Anatomies: The Ultrasonic Vibration and Thermo-Hydrodynamic Obturation versus Single-Cone Technique

This study aimed to assess the effectiveness of ultrasonic vibration and thermo-hydrodynamic obturation (VibraTHO) using two types of root canal sealers, in comparison to the single-cone (SC) technique and a calcium silicate-based root canal sealer in complex root canal anatomies. Thirty single-rooted human maxillary premolars with two canals that had a complex root canal anatomy of transverse anastomoses or ramifications were prepared and assigned to the following three experimental groups, according to the filling method: SE group, SC technique with Endoseal TCS; VE group, VibraTHO with Endoseal TCS; and VG group, VibraTHO with GuttaFlow 2. Each tooth was scanned using micro-computed tomography, and the volume percentages of the filling material were calculated. The analysis of variance was used to analyze the statistical differences between the three groups (p < 0.05). The mean volume of the filling material was higher in the VG and VE groups than that in the SE group (p < 0.05) along the apical to middle-to-coronal thirds, and significant differences were observed between each root canal area (p < 0.05), with the only exception being at the apical thirds between the VE and SE groups. The VibraTHO technique using GuttaFlow 2 can be a more effective root canal filling method for anatomically complex root canal systems than the SC technique with Endoseal TCS. On the other hand, the VibraTHO technique using Endoseal TCS has a limited effect on improving the quality of the root filling at the apical portion of anatomically complex root canal systems, compared to the SC technique with Endoseal TCS.

Micro-computed Tomographic Evaluation of the Quality of Root Canal Fillings in Mandibular Molars after Obturation for 54 Months

INTRODUCTION

The present study evaluated the percentage volume of voids in root canals of mandibular molars that had been obturated for 54 months.

METHODS

Thirty extracted human mandibular molars were instrumented and debrided. The teeth were assigned to 3 groups (n = 10) according to the filling technique and sealer used: the single-cone technique using AH Plus sealer (AHS; Dentsply Sirona Endodontics, Tulsa, OK) or EndoSequence BC sealer (BCS; Brasseler USA Dental LLC, Savannah, GA) and the warm vertical compaction technique using AH Plus sealer (AHW). The specimens were stored at 37°C and 100% humidity. Micro-computed tomographic imaging was used to scan each specimen 1 day 54 months after obturation. Data were analyzed using 1-way analysis of variance and the paired t test.

RESULTS

The percentage volume of voids in the teeth 1 day after obturation in the AHS group was higher than in the BCS group and the AHW group (P < .05). After 54 months, the proportion of voids decreased in all groups (P < .05). No significant difference was observed between the AHS group and the BCS group after 54 months. Teeth in the AHW group contained fewer voids than the AHS group (P < .05).

CONCLUSIONS

Voids in root canal filling were reduced 54 months after obturation. The warm vertical compaction technique achieved better root canal filling quality in mandibular molars than the single-cone technique when using AHS after long-term storage at 100% humidity.

Long-term porosity and retreatability of oval-shaped canals obturated using two different methods with a novel tricalcium silicate sealer

OBJECTIVE

To evaluate the percentage volume of voids and gaps in oval-shaped canals obturated using two different methods with a tricalcium silicate-based sealer after short- or long-term storage. The long-term effect of storage on the efficiency of removing filling material was also investigated.

MATERIALS AND METHODS

Forty premolar teeth with oval-shaped canals were instrumented to Reciproc R25 and obturated using single cone obturation (SCO) or warm vertical compaction (WVC) techniques with gutta-percha and HiFlow sealer. The specimens were stored at 100% humidity and 37°C for 2 weeks or 6 months and scanned using micro-computed tomography. Initial retreatment was performed up to a Reciproc R40, and the operating time was recorded. The residual material in the canal received a supplementary procedure using XP-endo Finisher R (XPFR) files. After each retreatment procedure, the specimens were rescanned.

RESULTS

The percentage volume of voids and gaps in the SCO group was higher than that of the WVC group at both 2 weeks and 6 months (P < 0.05). The percentage volume of the filling material removed after initial retreatment and XPFR cleaning was significantly higher in the 6-month group than in the 2-week groups (P < 0.05). The proportion of the residual material decreased significantly when XPFR files were used, compared to the initial retreatment group (P < 0.05) in both storage times.

CONCLUSION

The efficiency of retreatment in the oval-shaped canal was closely related to the storage time rather than the filling technique using a tricalcium silicate sealer. The XPFR instrument proved effective in the removal of the remaining materials from the oval-shaped canal.

CLINICAL RELEVANCE

Obturation of the oval-shaped canal with TSBS using the SCO technique in the coronal area needs to be optimized. The retreatment was less efficacious in freshly filled canals than aged filled canals.

Efficacy of XP-endo instruments in removing 54 month-aged root canal filling material from mandibular molars

OBJECTIVE

To investigate the effectiveness of XP-endo Shaper (XPS) and XP-endo Finisher R (XPFR) instruments in removing aged root filling material from root-treated mandibular molars.

METHODS

Thirty mandibular molars were instrumented and divided into three groups: single-cone obturation using AH Plus sealer (AHS) or EndoSequence BC sealer (BCS), and warm vertical compaction using AH Plus sealer (AHW). The specimens were stored at 100% humidity and 37 °C for 54 months. Retreatment was performed using XPS and XPFR. Micro-computed tomography was used to scan the specimens after 54 months, after XPS retreatment and after the supplementary approach using XPFR.

RESULTS

The XPS removed more filling material in the BCS and AHS groups, compared with the AHW group (P < 0.05). After supplementary instrumentation XPFR, the proportion of the remaining filling material decreased significantly in all groups (P < 0.05). The XPFR instruments were more efficient in removing filling material in the BCS group than in the AHS or AHW group (P < 0.05). The combined use of XPS and XPFR instruments efficiently removed filling material in the BCS group, followed by the AHS and AHW groups (P < 0.05).

CONCLUSIONS

Although the combined use of XPS and XPFR instruments helped remove the bulk of aged root filling material from mandibular molars, material removal from canals filled using warm vertical condensation in the critical apical area remains a concern.

CLINICAL SIGNIFICANCE

Removal of the aged filling materials using XP-endo instruments from the apical area is challenging when instrumented root canals are filled using warm vertical condensation.

Ultrasonic vibration and thermo-hydrodynamic technique for filling root canals: Technical overview and a case series

AIM

To present a novel root canal filling technique: Ultrasonic Vibration & Thermo-Hydrodynamic Obturation (VibraTHO), and its rationale with a series of cases.

SUMMARY

The VibraTHO technique was used to fill the root canals of three clinically challenging cases: A C-shaped mandibular molar with complex anatomy, a C-shaped mandibular molar with an infected root canal system and a periapical lesion that required retreatment, and apically bifurcating mesiobuccal canals with a common orifice in a maxillary second molar. The cases were followed up for 15, 7 and 37 months, respectively. After follow-up, normal periapical status was observed without any noticeable radiographic change in the root canal fillings in each case. Periapical radiographs revealed complete healing of the periapical area in cases with pre-operative periapical lesions.

Antibacterial, biological, and physicochemical properties of root canal sealers containing chlorhexidine-hexametaphosphate nanoparticles

OBJECTIVE

The aim of this study was to evaluate the influence of the incorporation of chlorhexidine-hexametaphosphate nanoparticles (CHX-HMP NPs) on antibacterial, cytotoxic and physicochemical properties of AH Plus (AH), MTA Fillapex (MTA) and Pulp Canal Sealer (PCS).

METHODS

The NPs were synthesized and characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), zeta potential, Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDS). The incorporation was made by weight, 2% and 5% of NPs. The antimicrobial activity, cytotoxicity, flow, radiopacity, setting time, solubility and pH were evaluated. The statistical analysis was performed by two-way analysis of variance test and Tukey post hoc test (P < 0.05).

RESULTS

SEM analysis showed the tendency for CHX-HMP NPs to cluster, the effective mean diameter measured by DLS: 169.39 nm and the zeta potential: -10.18 mV. The NPs were individually measured by AFM: 22.99-52.75 nm. EDS analysis identified the presence of C, N, O, Na, P, Cl. After incorporation: The Direct Contact Test showed an increase in the antimicrobial action of AH, PCS and MTA; the sealers showed a decrease in flow and at 24 h of immersion also an increase in solubility, but did not affect the radiopacity of the samples; AH setting time increased and MTA did not reach setting under any of the conditions tested. All samples showed a decrease in pH value as the immersion time progressed.

SIGNIFICANCE

The incorporation of NPs can improve the antimicrobial performance of endodontic sealers without impairing other biological and physicochemical properties.

Sealing Ability of AH Plus and GuttaFlow Bioseal

The objective of root canal obturation is to achieve a fluid-tight seal. Recently, GuttaFlow bioseal (GB), a root canal sealer composed of polydimethylsiloxane, gutta-percha particles, and bioactive glass ceramics, has been developed, to enhance the sealing ability of root canal filling material. The objective of this study was to assess the sealing ability of GB using a subnanoliter-scaled fluid-flow measuring device and to compare with that of AH Plus (AH). The fluid flow in root canal-filled teeth using either gutta-percha cone (GP) with AH (GAR; n = 10) or GP with GB (GBR; n = 10) and in GP inserted in AH blocks (GA; n = 10) or GP inserted in GB blocks (GB; n = 10) was measured. In addition, fluid flow in sealer blocks of AH (A; n = 10) and GB (B; n = 10), which served as negative controls, was measured. Root canal-filled teeth using GP without any sealer (GR) acted as positive controls (n = 10). The leakage was obtained by calculating the volume of moved water by time (s), after stabilization of the fluid flow was achieved. Statistical analysis was performed using the Kruskal–Wallis test and Mann–Whitney U-test with Bonferroni correction. A p value less than 0.00238 (0.05/21) was considered significantly different. The mean leakages (nL/s) in the groups are as follows: GAR, 0.0958 ± 0.0543; GBR, 0.0223 ± 0.0246; GA, 0.0644 ± 0.0803; GB, 0.0267 ± 0.0182; A, 0.0055 ± 0.0057; B, 0.0052 ± 0.005; and GR, 0.2892 ± 0.3018. The mean leakage in the GBR group was lower than that in the GAR group (p = 0.001), while the mean leakages in the GA and GB groups were not significantly different. GuttaFlow bioseal can be useful in single-cone obturation technique.

Dentin moisture conditions strongly influence its interactions with bioactive root canal sealers

Objectives

It is known that bioactive materials interact with the dentin to undergo biomineralization. The exact role of moisture in this interaction is unknown. Here, we investigate the effects of dentin moisture conditions on the dislocation resistance of two bioactive root canal sealers (MTA Fillapex [Angelus Solucoes Odontologicas] and GuttaFlow BioSeal [Colténe/Whaledent AG]) at 3 weeks and 3 months after obturation.

Materials and Methods

Mandibular premolars (n = 120) were prepared and randomly divided into 3 groups based on the dentin condition: group 1, dry dentin; group 2, moist dentin; group 3, wet dentin. Each group was divided into 2 subgroups for root canal filling: MTA Fillapex and GuttaFlow BioSeal. Dislocation resistance was evaluated by measuring the push-out bond strength at 3 weeks and 3 months. Failure modes were examined under a stereomicroscope. Data were statistically analyzed by Kruskal-Wallis test with a significance level of 5%.

Results

Moist dentin resulted in higher bond strength values for both materials at both time points. This was significantly higher than wet and dry dentin for both the sealers at the 3 months (p < 0.05), while at 3 weeks it was significant only for GuttaFlow Bioseal. The different moisture conditions demonstrated similar trends in their effects on the dislocation resistance of the 2 root canal sealers.

Conclusions

The dentin moisture conditions had a significant impact on its interaction with the bioactive materials tested. Maintaining moist dentin, but not dry or wet dentin, may be advantageous before the filling root canals with bioactive sealers.

Outcome of Root Canal Treatments Using a New Calcium Silicate Root Canal Sealer: A Non-Randomized Clinical Trial

Background: The aim of this study was to compare the success rate of root canal treatments undertaken using a calcium silicate root canal sealer in combination with a single cone with non-calcium silicate cement and warm vertical condensation. Methods: 150 necrotic or pulpitic teeth were treated. (REC: 08/H0804/79). Following standardized root canal chemo-debridement. The canals were obturated using warm vertical condensation of gutta-percha and epoxy-based sealer (AH plus) or a calcium silicate sealer (BioRoot^TM RCS) with a single cone technique. Follow-up assessment was conducted at 12 months using Cone Beam Computed Tomography (CBCT). Results: At 1-year recall, 104 teeth were assessed (51 AH plus, 53 BioRoot^TM RCS). The success rate using loose criteria for the CBCT images and PA radiographs was respectively 80% and 89% in the AH plus/warm vertical condensation group, 84% and 90% in the BioRoot^TM RCS/single cone group. There was no statistically significant difference between the two groups (Fisher exact test p value 0.6099 for the CBCT images). Conclusion: Within the limitations of this non-randomized trial, a calcium silicate cement in combination with single cone resulted in a similar proportion of successful cases compared to warm vertical condensation and epoxy-based sealer.

Root canal configuration and root wall thickness of first maxillary premolars in an Israeli population. A Cone-beam computed tomography study

Anatomical features of first maxillary premolars may greatly affect endodontic and following restorative treatments. The aim of this study was to evaluate root canal configuration and root wall thickness of first maxillary premolars using a preexisting CBCT database. A CBCT database of 400 first maxillary premolar was used to study canal configuration, presence of furcation-facing groove on the buccal root and root wall thickness. Root wall thickness was measured from axial CBCT slices at three critical points of the root: The most coronal part of the furcation-facing groove in the buccal root, when present, the CEJ level of the palatal root and 5 mm apically to the CEJ level of the palatal root. Vertucci Type IV configuration was the most common among all teeth, but in single-rooted teeth, Vertucci Type II was predominant. The mean thickness of the buccal root in the area of a furcation-facing groove was 1.1 (±0.2) mm, but in 39% of the cases, it was thinner than 1 mm. The mean thickness of the palatal root at 5 mm from the CEJ was 1.1 (±0.2), but in 28% of the cases, it was thinner than 1 mm. Thickness of root dentin walls of first maxillary premolars varies and may be limited at critical points in both buccal and palatal roots. In case the patient has a previous CBCT scan it may be useful for planning treatment of first maxillary premolars, in order to recognize and avoid potential risks such as furcation-facing groove, thin dentin walls in critical areas and presence of Type II Verucci canal, all of which may dictate less invasive procedures, using smaller files.

Dentinal Tubule Penetration and Dislocation Resistance of a New Bioactive Root Canal Sealer Following Root Canal Medicament Removal Using Sonic Agitation or Laser-Activated Irrigation

Objective:

To investigate the influence of sonic agitation or laser-activated irrigation techniques on the removal chlorhexidine (CHX) and modified triple antibiotic paste (mTAP) on the sealer penetration depth and dislocation resistance of Guttaflow Bioseal.

Methods:

Single-rooted mandibular premolars (n=96) were prepared with rotary nickel titanium instruments and randomly divided into two groups (n=48) based on the intracanal medicaments used: Group 1, mTAP; Group 2, CHX gel. After 7 days, the specimens in each group were divided into three subgroups (n=16) based on the supplementary irrigation technique used to remove the medicaments: laser activated irrigation (Er, Cr: YSGG laser, Waterlase MD, Biolase Technology Inc., San Clemente, CA, USA), sonic agitation (EndoActivator, Dentslpy Sirona Endodontics, PA, USA) and syringe-and-needle irrigation (control) techniques. Canals were filled with single matched-taper gutta-percha cone and a calcium silicate-based sealer (GuttaFlow® Bioseal, Coltène/Whaledent, Langenau, Germany). At the end of three weeks, sealer penetration was investigated using confocal microscopy (n=6), and dislocation resistance was calculated by measuring the push-out bond strength (n=10). Statistical analysis was performed using three-way analysis of variance (ANOVA) and Tukey post-hoc test (P=0.05).

Results:

Laser activated irrigation resulted in significantly higher depth of sealer penetration compared to sonic agitation and syringe irrigation (P<0.01). The average sealer penetration depths were recorded as 846.6 µm, 786.5 µm and 505 µm in the Er, Cr: YSGG laser, EndoActivator and control groups, respectively. The mean bond strength obtained in group 3 (syringe-and-needle irrigation) was significantly less than the other groups (P<0.05). The mean values were 9.08 in the Er, Cr: YSGG laser group, 8.44 in the EndoActivator group and 5.08 in the needle group.

Conclusion:

Er,Cr;YSGG laser irrigation to remove the medicaments was advantageous to other irrigation techniques in sealer penetration and dislocation resistance of the sealer.