Quality of obturation achieved by an endodontic core-carrier system with crosslinked gutta-percha carrier in single-rooted canals

Quality of Root Canal Filling in Curved Canals Utilizing Warm Vertical Compaction and Two Different Single Cone Techniques: A Three-Dimensional Micro-Computed Tomography Study

Statement of the Problem

Successful endodontic treatment depends on three-dimensional (3D) root canal filling to prevent the leakage of residual bacteria. Different obturation techniques with different sealers should be compared by employing advanced assessment tools.

Purpose

This study compared the obturation quality of warm vertical compaction (WVC) and two different single-cone (SC) techniques using micro-computed tomography (micro-CT).

Materials and Method

Thirty-three extracted maxillary molars with mesial root canal curvature of 20‒40º were prepared in vitro with One-Curve files and randomly assigned to three groups (n=11) for root canal obturation with WVC, SC technique with AH Plus sealer (SC-AH), or SC technique with SureSeal bioceramic (BC) sealer (SC-Su). The root canals underwent micro-CT examinations before and after obturation to determine the volume percentages (VPs) of voids and gaps at different distances from the apex (coronal, middle, and apical thirds). Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests.

Results

The highest VP of voids and gaps was recorded in the SC-Su group, with no significant difference from other groups (p> 0.05). There were significant differences in VP of gaps at different distances from the apex (p<0.05). The VPs of gaps in the apical third of all the samples were significantly higher than in the coronal and middle thirds. However, the difference in VP of voids was not significant at different distances from the apex (p>0.05).

Conclusion

None of the tested techniques could provide a void-free and gap-free filling. The apical third of the canals showed the highest VP of gaps in all obturation techniques.

Effect of Obturation Techniques on the Quality of Root Canal Fillings: A Systematic Review and Meta-analysis of in Vitro Studies

Introduction

The current study aimed to compare the quality of root canal obturation performed with cold lateral condensation with other obturation techniques.

Materials and Methods

Diverse Search was conducted using six electronic/academic databases following PICOS (i.e. population, intervention, control, outcomes, and study design) strategy: (P) Extracted mature permanent teeth; (I) Obturation techniques except for cold lateral condensation; (C) Cold lateral condensation tyechnique; (O) Quality of root canal obturation; and (S) In vitro studies assessing parameters using micro-computed tomography. The statistical method used for the meta-analyses was the "inverse variance DerSimonian-Laird test". The heterogeneity data was calculated using the T2, Cochran Q test, and I2 statistics.

Results

Fifteen studies were included for the final analysis; one had a low risk of bias, eight a moderate risk, and six a high risk of bias. Ten studies were selected for meta-analyses; three studies comparing cold lateral condensation with carrier-based gutta-percha techniques [P=0.96; mean difference (MD)=-0.02; confidence interval (CI): (-0.77, 0.73); I2=21%]; three comparing cold lateral condensation with single-cone techniques [P=0.75; MD=-0.39; CI: (-2.77, 1.99); I2=92%]; two comparing cold lateral condensation and thermo-plasticized injectable techniques [P=0.37; MD=5.91; CI: (-7.13,18.94); I2=99%]; and five comparing cold lateral condensation with warm vertical condensation techniques [P<0.0001; MD=5.29; CI=(2.84, 7.74); I2=92%]. The overall effect reported significant results [P=0.0003; MD=2.69; CI=(1.23, 4.16); I2=96%]; favoring fewer voids and gaps for the other used obturation techniques.

Conclusions

Cold lateral condensation and single-cone techniques presented no statistical differences. Nonetheless, Warm vertical condensation technique had better results compared to cold lateral condensation.

Comparison of obturation quality in natural and replica teeth root-filled using different sealers and techniques

OBJECTIVES

This study aims to assess the obturation efficacy of sealers placed with different techniques using microcomputed tomography (µCT) and assess the influence of µCT testing parameters on the obturation data obtained.

MATERIALS AND METHODS

Incisors and mesial roots of lower molars with standardized root length were scanned using µCT, and one tooth of each type was 3D printed in acrylic. Two obturation techniques (warm vertical and single cone) and 4 sealer types (AH Plus, BioRoot RCS, Totalfill BC, and Bio-C Sealers) were assessed following storage in Hank's balanced salt solution for 3 and 6 months by assessing gap and void volume percentages on both natural and replica incisor and molar roots. The storage solution was analysed to assess calcium ion leaching. The influence of temperature, tooth positioning, and moisture content of the teeth while µCT scanning was also investigated.

RESULTS

The obturation quality in the incisor group was the same using both natural teeth and replicas (p > 0.05). No changes in void volume were identified when comparing the same sealer using different obturation techniques. The premixed sealers used in single-cone obturation exhibited high void volume in the 3D printed replicas in the long term. The temperature, positioning, and moisture content of the teeth did not affect the outcome of µCT testing.

CONCLUSIONS

BioRoot RCS, Totalfill BC, and Bio-C Sealers are suitable for obturation of both complex and simple root canal systems using different obturation techniques with BioRoot RCS exhibiting the highest calcium ion release. 3D printed acrylic teeth can be used to assess the obturation quality in uncomplicated root canal systems. µCT parameters had no significant effect on the µCT measurement.

CLINICAL RELEVANCE

The single-cone obturation technique with hydraulic sealer is a simple technique that can be used for obturation of all root canal systems.

Assessment of the Dentinal Surface Adaptation Efficacy of Different Obturation Systems with Bioceramic Sealer: A Scanning Electron Microscope Study

AIM

Aim of this study was to evaluate the dentinal surface adaptation effectiveness of different obturation methods with bioceramic sealer.

MATERIALS AND METHODS

Sixty recently removed human permanent premolars of the mandible having a solitary, straight as well as completely produced root were chosen on the basis of clinical/radiographic evaluation. The coronal parts of the premolars were subjected to sectioning at the cementoenamel junction (CEJ) with the aid of a water-cooled diamond disk. The regular access opening was done, following which the working length was visually estimated by deducting 1 mm from the length of a 10 size K-file (Dentsply, OK, USA) at the apex. Subsequent to preparing the radicular canal, the premolar specimens were randomly allocated to one of the following three groups. Group I: Lateral compaction (LC) technique; group II: Warm vertical compaction (WVC) technique; and group III: Thermafil obturation technique. Following obturation, the samples were subjected to sectioning in the horizontal direction at three dissimilar points as follows: First at the cervical third, then at the middle, and at the apical third employing a minitom under water irrigation to put off overheating. Internal spaces amid the radicular dentin as well as the obturating agents were appraised with the use of a scanning electron microscope (SEM).

RESULTS

Intragroup analysis showed that higher gaps were noted at the coronal level (2.30 ± 0.04), in pursuit by middle part (1.12 ± 0.02) and apical third (0.70 ± 0.02) for the LC method. With the WVC procedure, higher gaps were situated in the coronal level (1.96 ± 0.07), again in pursuit by middle part (1.02 ± 0.02) and apical third (0.86 ± 0.04). Even with the Thermafil obturation method, higher gaps were noted at the coronal level (0.92 ± 0.10), in pursuit by middle part (0.67 ± 0.05) and apical third (0.57 ± 0.01). No statistically significant difference was noted within the group. Upon intergroup comparative assessment of dentinal surface adaptation with dissimilar obturation systems at coronal, middle and apical thirds, there was a statistically noteworthy disparity amid the groups (p <0.001).

CONCLUSION

This research arrived at a conclusion that the most superior dentinal adaptation of bioceramic sealer was procured when the Thermafil obturation method was employed for obturating the root canals compared to the WVC technique as well as the LC technique.

CLINICAL SIGNIFICANCE

Numerous endodontic substances have been promoted for obturating the root canal areas. Majority of the methods use a core substance, in addition to a sealer. Despite the type of core agent, a sealer indispensable to each technique offers a fluid-tight sealing. The oral physicians' comprehension of the characteristics of the endodontic sealer plus method used, enhances the therapeutic effect.

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.

A micro-computed tomographic assessment of oval-shaped root canals obturated with bioceramic sealer using different obturation techniques

Background/Aim: To evaluate void volumes in oval-shaped root canals obturated with three different obturation systems using microcomputed tomography (micro-CT). Material and Methods: Twenty-four distal roots of mandibular molar teeth canals were prepared and randomly divided into three groups (n = 8 in each group). The canals were obturated using single cone (SC), GuttaCore (GC), and warm vertical compaction (WVC) techniques. Each specimen was scanned using a micro-CT device. The volumes of the voids were calculated, and the data were statistically analyzed using a one-way analysis of variance and post hoc Tukey's (P < .05). Results: The void volumes in the WVC group were significantly lower than those in the other groups (P < .05). When different root canal parts were examined, the void volumes increased significantly from the apical to the coronal level in the GC and SC groups (P < .05). In the WVC group, most voids were observed in the middle part (P < .05), whereas there was no significant difference in void volumes in the coronal and apical parts (P > .05). Conclusions: None of the systems provided void-free root filling. However, the void volume using the WVC system was significantly lower than that observed using the other systems.

What Are the Chances of Resilon to Dominate the Market Filling Materials for Endodontics?

This paper is a literature review with additional virtual analyses of the authors’ own experimental research results. Knowledge from various areas was synergistically combined, appropriately for concurrent engineering, presenting several possible methodological approaches used in research, optimizing the selection of engineering materials and the conditions of their application with particular application in endodontics. Particular attention was paid to the theoretical aspects of filling material strengths, weaknesses, opportunities, and threats SWOT analysis. Attention was paid to the original concepts of Sustainable Dentistry Development in conjunction with Dentistry 4.0, which includes endodontics as an important element. The dentists’ actions, among others, in conservative dentistry, along with endodontics, requires close cooperation with engineers and the enginering sciences. Methods of root canal preparation were described, together with selected tools, including those made of nitinol. Principles concerning the process of cleaning and shaping the pulp complex are presented. The importance of obturation methods, including the Thermo-Hydraulic-Condensation THC technique, and the selection of filling materials with the necessary sealants for the success of endodontic treatment are discussed. The experimental studies were carried out in vitro on human teeth removed for medical reasons, except for caries, for which two groups of 16 teeth were separated. After the root canal was prepared, it was filled with studs and pellets of a filling material based on polyester materials, which has gained the common trade name of resilon or, less frequently, RealSeal (SybronEndo) with an epiphany sealant. The teeth for the first group were obturated by cold lateral condensation. In the second case the obturation was performed using the Thermo-Hydraulic-Condensation technique using System B and Obtura III. The experimental leakage testing was done using a scanning electron microscope SEM and a light stereoscopic microscope LSM, as typical research tools used in materialography. The research results, in a confrontation with the data taken from the literature studies, do not indicate the domination of resilon in endodontics.

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.

Is Gutta-Percha Still the “Gold Standard” among Filling Materials in Endodontic Treatment?

The paper is an extensive monographic review of the literature, and also uses the results of the authors’ own experimental research illustrating the noticed developmental tendencies of the filling material based on gutta-percha. The whole body of literature proves the correctness of the research thesis that this material is the best currently that can be used in endodontics. Caries is one of the most common global infectious diseases. Since the dawn of humankind, the consequence of the disease has been the loss of dentition over time through dental extractions. Both tooth caries and tooth loss cause numerous complications and systemic diseases, which have a serious impact on insurance systems and on the well-being, quality, and length of human life. Endodontic treatment, which has been developing since 1836, is an alternative to tooth extraction. Based on an extensive literature review, the methodology of qualifying patients for endodontic treatment was analyzed. The importance of selecting filling material and techniques for the development and obturation of the root canal during endodontic treatment was described. Particular attention was paid to the materials science aspects and the sequence of phase transformations and precipitation processes, as well as the need to ensure the stoichiometric chemical composition of Ni–Ti alloys, and the vacuum metallurgical processes and material processing technologies for the effects of shape memory and superelasticity, which determine the suitability of tools made of this alloy for endodontic purposes. The phenomena accompanying the sterilization of such tools, limiting the relatively small number of times of their use, play an important role. The methods of root canal preparation and obturation methods through cold side condensation and thermoplastic methods, including the most modern of them, the thermo-hydraulic condensation (THC) technique, were analyzed. An important element of the research hypothesis was to prove the assumption that to optimize the technology of development and obturation of root canals, tests of filling effectiveness are identified by the density and size of the gaps between the root canal wall, and the filling methods used and devices appropriate for material research, using mainly microscopy such as light stereoscopic (LSM) and scanning electron (SEM). The most beneficial preparations were obtained by making a longitudinal breakthrough of 48 natural human teeth, extracted for medical reasons, different from caries, with compliance with all ethical principles in this field. The teeth were prepared using various methods and filled with multiple obturation techniques, using a virtual selection of experimental variants. The breakthroughs were made in liquid nitrogen after a one-sided incision with a narrow gap created by a diamond disc using a materialographic cutter. The best effectiveness of the root canal filling was ensured by the technology of preparing the root canals with K3 rotary nitinol tools and filling the teeth with the THC thermoplastic method using the System B and Obtura III devices with studs and pellets of filling material based on gutta-percha after covering the root canal walls with a thin layer of AH Plus sealant. In this way, the research thesis was confirmed.

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.

Virtual Approach to the Comparative Analysis of Biomaterials Used in Endodontic Treatment

The importance of endodontics is presented within our own concept of Dentistry Sustainable Development (DSD) consisting of three inseparable elements; i.e., Advanced Interventionist Dentistry 4.0 (AID 4.0), Global Dental Prevention (GDP), and the Dentistry Safety System (DSS) as a polemic, with the hypothesis of the need to abandon interventionist dentistry in favour of the domination of dental prevention. In view of the numerous systemic complications of caries that affect 3−5 billion people globally, endodontic treatment effectively counteracts them. Regardless of this, the prevention of oral diseases should be developed very widely, and in many countries dental care should reach the poorest sections of society. The materials and methods of clinical management in endodontic procedures are characterized. The progress in the field of filling materials and techniques for the development and obturation of root canals is presented. The endodontics market is forecast to reach USD 2.1 billion in 2026, with a CAGR of 4.1%. The most widely used and recognized material for filling root canals is gutta-percha, recognized as the “gold standard”. An alternative is a synthetic thermoplastic filler material based on polyester materials, known mainly under the trade name Resilon. There are still sceptical opinions about the need to replace gutta-percha with this synthetic material, and many dentists still believe that this material cannot compete with gutta-percha. The results of studies carried out so far do not allow for the formulation of a substantively and ethically unambiguous view that gutta-percha should be replaced with another material. There is still insufficient clinical evidence to formulate firm opinions in this regard. In essence, materials and technologies used in endodontics do not differ from other groups of materials, which justifies using material engineering methodology for their research. Therefore, a detailed methodological approach is presented to objectify the assessment of endodontic treatment. Theoretical analysis was carried out using the methods of procedural benchmarking and comparative analysis with the use of contextual matrices to virtually optimize the selection of materials, techniques for the development and obturation of root canals, and methods for assessing the effectiveness of filling, which methods are usually used, e.g., in management science, and especially in foresight research as part of knowledge management. The results of these analyses are presented in the form of appropriate context matrices. The full usefulness of the research on the effectiveness and tightness of root canal filling using scanning electron microscopy is indicated. The analysis results are a practical application of the so-called “digital twins” approach concerning the virtual comparative analysis of biomaterials used in endodontic treatment.

Root Canal Filling Quality Comparison of a Premixed Calcium Silicate Endodontic Sealer and Different Carrier-Based Obturation Systems

Background: The number of voids within the root canal obturation is a relevant parameter to describe the quality of the technique, as well as to predict long-term prognosis. The aim of this study was to evaluate the quality of root canal obturation in curved root canals filled with Thermafil, GuttaCore, GuttaFusion and lateral compaction with AH Plus and EndoSequence BC sealer, by means of percentage of gutta-percha and sealer filled area. Methods: 200 curved canals of mandibular molars were divided in five groups (n = 40). Each specimen was evaluated at 3, 6 and 9 mm from the apex. A total of 600 samples were analyzed. Obturation was performed with either Thermafil (TH), GuttaCore (GC), GuttaFusion (GF) or lateral compaction (LC), using AH Plus as sealer. In another group EndoSequence BC sealer (BC) was used. Subgroups (n = 20) were made depending on the use of sonic activation during the placement of the sealer. The percentage of total obturation material was analyzed as an indirect measurement of percentage of voids. Results: GF showed a better performance at the apical level, while GC showed the higher percentage of total obturation at the coronal area. No differences were observed for the activation of sealers in any of the groups. Statistical analysis was performed by using two-way ANOVA. Statistical significance was set at CI: 95% (p < 0.05). Conclusions: Sonic activation of sealers did not show any benefit to avoid the presence of voids within obturation of curved canals. Following the manufacturer recommendations, we found that TH did not show benefits when applied to curved canals.

Correlation among Root Canal Configuration, Quality of Filling, and Its Sealability

Objective  This study aimed to evaluate the existence of possible correlations among root canal configuration, quality of filling, and its sealability.

Materials and Methods  Sixty human mandibular central incisors were selected for this study. The teeth were prepared with the Profile 04 system up to instrument 35/0.04 and irrigated with 2.5 mL of 2.5% sodium hypochlorite at each instrument change. Root canal filling was performed by the lateral compaction technique, using gutta-percha and an epoxy resin-based sealer (AH Plus) labeled with 0.1% Rhodamine B dye. Afterward, the specimens were submitted to fluid filtration tests to assess the sealability of the filling. Cross-sections were obtained at −3, −6, and −8 mm from the root apex and submitted to a metallographic treatment to determine the root canal configuration and the percentage of gutta-percha filled areas. The data were statistically analyzed by the Grubbs test. Pairs of correlations were analyzed by applying the Spearman test at a level of significance of 5%.

Results  No correlation was observed among the analyzed variables as follows: root canal configuration versus filling quality (Spearman’s rho = 0.031); filling quality versus sealability (Spearman’s rho = 0.219); and root canal configuration versus sealability (Spearman’s rho = 0.184).

Conclusion  The root canal configuration did not affect the quality of the filling and its sealability.

Efficacy of prototype endodontic obturators for novel root canal obturation techniques using a resin-based sealer in various powder-liquid ratios

PURPOSE

This study aimed to examine novel techniques using prototype endodontic obturators to obturate a resin-based sealer.

METHODS

Powder-liquid ratios of MetaSEAL Soft were changed to obtain suitable root canal sealing, and the physical properties for various powder-liquid ratios were analyzed according to ISO-6876. Tensile bond strength was also examined. Prototype endodontic obturators with a combination of thread numbers and pitch angles were analyzed for sealing ability after MetaSEAL Soft was obturated in simulated root canals.

RESULTS

Powder-liquid ratios of 1.0:1, 1.1:1, 1.2:1, and 1.3:1 showed suitable physical properties; however, flow for 1.4:1 was below a standard value. Tensile bond strength increased gradually when the powder-liquid ratio changed from 1.0:1 to 1.3:1, and 1.3:1 and 1.4:1 showed the highest and lowest bond strengths, respectively. Sealing ability increased when pitch angles of the obturators were 5°, 8°, and 11°; 11° showed the best results. Similarly, sealing ability increased when the thread number was 12, 17, and 22 pitches; 22 showed the best results.

CONCLUSION

These findings suggest that the prototype endodontic obturator can be useful for obturating MetaSEAL Soft, and a powder-liquid ratio of 1.3:1 MetaSEAL Soft may be the most suitable for achieving excellent sealing.

Assessment of Quality of Root Canal Filling with C Point, Guttacore and Lateral Compaction Technique: A Confocal Laser Scanning Microscopy Study

Objective:

The purpose of this in vitro study was to compare the quality of root canal filling of C Point, GuttaCore and lateral compaction using confocal laser scanning microscopy.

Methods:

Ninety recently extracted human mandibular incisors with single canal were selected. Canals were prepared with ProTaper instruments to size F3 and obturated using C Point, GuttaCore or lateral compaction technique. Endosequence BC sealer was labeled with Rhodamine B dye to allow analysis under a confocal microscope. The percentages of gutta-percha filled area (PGFA), sealer filled area (PSFA), voids (POV) and interfacial adaptation (IA) was assessed at 2, 5 and 8 mm from the apex, using image analysis software. Kruskal–Wallis followed by Mann Whitney U tests were used for data analysis, and the P value was set at 0.05 (P=0.05).

Results:

No significant difference was seen among the three groups at 2 mm level for PGFA, PSFA and voids (P>0.05). At 5 and 8 mm levels, canals filled with GuttaCore had significantly higher PGFA and lower PSFA than lateral compaction and C Point. Highest POV was seen for lateral compaction group followed by C Point and GuttaCore.

Conclusion:

Out of the three techniques examined, best results in terms of quality of root canal filling were observed for GuttaCore. C Point system was found to be associated with internal defects such as tears and delamination which may adversely affect the long term performance of this system.

Effect of Different Irrigation Solutions on the Diffusion of MTA Cement into the Root Canal Dentin

(1) Aim: This study aims to analyze the in vitro infiltration of a silicate root canal sealer into dentinal tubules after using different endodontic irrigating solutions. (2) Methods: Twenty-nine teeth with single roots were separated into three groups according to the final irrigation protocol: G1 n = 10) = 17% EDTA (ethylenediaminetetraacetic acid) + 3.0% sodium hypochlorite (NaOCl), G2 (n = 10) = 17% EDTA + 2.0% chlorhexidine and G3 (Control group, n = 9) = 17% EDTA + saline solution. Root canals were filled using cold lateral compaction technique with MTA Fillapex sealer and gutta-percha. The sealer was labeled with rhodamine B. The teeth were segmented at the middle and third apical sections, which were visualized using 10× confocal laser microscopy to determine the sealer penetration percentage. (3) Results: In the apical section, no statistically significant differences were found between the groups regarding sealer penetration. In the middle section, Group 1 obtained the highest percentage, and Group 2 the lowest (p = 0.004). Group 1 also presented statistically significant differences in the Control Group (p = 0.031) and had close sealer penetration values. Meanwhile, the Control Group (p = 0.023) and Group 2 (p = 0.029) revealed a significant decrease of sealer penetration between the apical and middle sections. (4) Conclusion: The obtained results support that final irrigation with NaOCl promoted similar sealer penetration in the apical and middle sections. On the other hand, a significant decrease in the sealer penetration of the middle section was observed for the chlorhexidine and saline groups. Compared to other irrigant solutions, NaOCl promotes more uniform sealer penetration, which can correlate with better sealing and, consequently, higher endodontic treatment success.

Microscopic and chemical evaluation of the filling quality of five obturation techniques in oval-shaped root canals

OBJECTIVES

The aim of this study was to assess the filling quality of five obturation techniques in oval-shaped root canals.

MATERIALS AND METHODS

A total of 212 mandibular first molars with one distal oval canal were selected. Distal canals, shaped with WaveOne Gold Primary, were randomly divided in five groups (n = 40) for obturation: continuous wave condensation, GuttaCore, Thermafil, single cone with AH plus, and single cone with BioRoot RCS. The proportions of gutta-percha-filled areas (GPFA), sealer-filled areas (SFA), void areas (VA), and the sealer/gutta tags into dentinal tubules at 4 mm and 2 mm from the apex were analyzed by an optical numeric microscope, SEM, and energy-dispersive X-ray (EDX). Data were then compared by Kruskal-Wallis one-way ANOVA on ranks (α = 0.05).

RESULTS

At 4 mm, a statistically significant higher GPFA and lower SFA were observed in the GuttaCore and Thermafil groups compared with the 3 other groups. A statistically significant lower VA was observed in the continuous wave condensation, GuttaCore, and Thermafil groups than in the two single-cone groups. At 2 mm, there were a statistically significant higher GPFA and lower SFA and VA in GuttaCore and Thermafil groups than in the 3 other groups. At the two levels investigated, the presence of gutta-percha tags was clearly demonstrated for GuttaCore and Thermafil groups; no tags were observed in the 3 other groups.

CONCLUSIONS

Obturation quality was overall improved in GuttaCore and Thermafil groups.

CLINICAL RELEVANCE

Carrier-based techniques may significantly improve the filling quality compared to continuous wave condensation and single-cone technique. The single-cone technique might have inherent limitations especially in oval root canals regardless of the sealer used.

Filling ability of three variants of the single-cone technique with bioceramic sealer: a micro-computed tomography study

The present study evaluated the quality of single-cone root canal fillings with bioceramic (BC) sealer using three different techniques by means of micro-computed tomography (micro-CT). The canals of 30 extracted single-rooted permanent teeth were shaped with R40 Reciproc blue files and filled with the single-cone technique (SCT). BioRoot RCS BC sealer was placed inside the canals with one of the following master cones: R40 cone to working length (RWL, n = 10); R40 cone trimmed 1 mm short of working length (RWL-1, n = 10); non-standardized gutta-percha cone to working length (NSWL, n = 10). A quantitative and qualitative micro-CT analysis assessed the filling quality and internal/external voids formation. Collected data underwent statistical analysis by multivariate one-way analysis of variance (α = 0.05). In all groups, the voids were minimal and prevalently external. The NSWL and RWL-1 groups had increased sealer ratios in the whole canal and the apical canal portion, respectively. The lowest amounts of voids were found in the RWL group; the void volumes were slightly greater in the RWL-1 mm and NSWL groups, especially at the apical level. Two alternative SCTs showed satisfactory filling ability, uniform distribution of the BC sealer, and a minimally increased voids formation compared to the standard SCT with dedicated cone. The two tested alternative SCTs could take advantage of the beneficial characteristics of the BC sealer, which evenly filled the endodontic space, ideally sealing both the major and the accessory communications with the periodontium.

GuttaCore Pink, Thermafil and Warm Vertically compacted gutta-percha retreatment: Time required and quantitative evaluation by using ProTaper files

The goal of non-surgical treatment is to obtain an access to the root canal system in order to remove the previous filling. We analized 45 human single-canal roots, mesial roots of mandibular molars and distal roots of maxillary molars without previous endodontic treatment, fractures, resorptive defects or open apices. We evaluated the time required to retreat root canals obturated by a new generation of GuttaCore, GuttaCore Pink^®, compared to Thermafil^® and Warm Vertically compacted gutta-percha, by using ProTaper^® Retreatment and ProTaper^® Universal. Moreover, a quantitative analysis of residual filling material in the canal after retreating and shaping was performed. The Kruskal-Wallis and Dunn's test were used to determine significant differences. Our data show that the GuttaCore Pink^® can be removed from the root canal system in a lower amount of time compared to the Thermafil^®. Concerning the amount of residual filling material, there are no significant differences between the three groups.

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

INTRODUCTION

The aim of this study was to compare the quality of root fillings completed by a modified single-cone (MSC) technique with 3 different sealers after minimal instrumentation and multisonic cleaning of root canals of maxillary first molars.

METHODS

Root canals of 18 maxillary first molars were instrumented to size 15/.04 taper using rotary files. Sodium hypochlorite 5.25% was used during instrumentation; the final cleaning was performed by the GentleWave System (Sonendo Inc, Laguna Hills, CA). The specimens were allocated into 3 groups and root filled by the MSC technique using a size fitted gutta-percha master cone and GuttaFlow Bioseal (Coltene Whaledent GmBH + Co KG, Langenau, Switzerland), GuttaFlow 2 (Coltene Whaledent GmBH + Co KG), and MTA Fillapex (Angelus Industria de Produtos Odontológicos S/A, Londrina, PR, Brazil) sealers. Micro-computed tomographic scans were obtained before and after instrumentation, post-GentleWave, and after obturation. Reconstructed images were analyzed for the volumetric percentage of filling materials. Mesiobuccal roots of the selected teeth were sectioned at 0.5-mm increments starting at the apex of the root. The cross sections were further examined using a light microscope.

RESULTS

The 3 groups had 90%-99% of the canal space filled with the root filling material. The mean volume of the filling material was higher in the GuttaFlow Bioseal and GuttaFlow 2 groups than in the MTA Fillapex group (P < .05). There was no significant difference among the apical, middle, and coronal thirds. The cross-sectional images showed no obvious gaps or voids in the GuttaFlow groups. After instrumentation, 49 of the 189 canal thirds (25.9%) had hard tissue debris in the root canal system. After GentleWave cleaning, only 4 of 63 canals (6.3%) and 4 of the 189 canal thirds (2.1%) still had debris.

CONCLUSIONS

The MSC method with GuttaFlow 2 and GuttaFlow Bioseal sealers after multisonic cleaning of minimally instrumented molar canals resulted in high-quality root fillings. Multisonic cleaning of minimally instrumented molars seems to be effective in debris removal.

Efficacy of the ProTaper retreatment system in removing Thermafil, GuttaCore or vertically compacted gutta-percha from curved root canals assessed by micro-CT

AIM

To evaluate ex vivo the efficacy of ProTaper Universal Retreatment files (Dentsply Sirona, Ballaigues, Switzerland) in removing Thermafil, GuttaCore (both Dentsply Sirona) or vertically compacted gutta-percha from curved root canals using micro-CT.

METHODOLOGY

Sixty curved molar roots with the same mean canal curvatures and radii in two directions were prepared using ProFile instruments (Dentsply Sirona) to size 30 with .04 taper and obturated with either Thermafil, GuttaCore or vertically compacted gutta-percha and AH Plus (n = 20). Specimens were retreated using the ProTaper Universal Retreatment files D1, D2 and D3 to working length, and root canal preparation was completed with ProTaper Next (Dentsply Sirona) to size ×4. Percentages of residual filling material and dentine removal were assessed using micro-CT imaging. Working time and procedural errors were recorded. Statistical analysis was performed using Kruskal-Wallis and Wilcoxon tests.

RESULTS

No significant differences between carrier-based and warm vertical compaction regarding residual filling material (14.2-19.3%) and dentine removal (2.7-3.2 mm³ ) were detected (P > 0.05). Time to reach working length was significantly faster for canals filled with GuttaCore than that observed for Thermafil and warm vertical compaction (P < 0.05). Five lateral perforations with the D3 file occurred during retreatment, one in the Thermafil and four in the vertical compaction group.

CONCLUSIONS

Remaining filling material and dentine removal were similar for all canal filling techniques. Regaining working length was significantly faster for GuttaCore compared with Thermafil and vertically compacted gutta-percha. Procedural errors occurred during retreatment of severely curved root canals with the ProTaper Universal Retreatment files in 5 of 60 canals (8%).

Micro-CT assessment of the sealing ability of three root canal filling techniques

This study used micro-CT to compare three obturation techniques with respect to void occurrence in canals filled with bioceramic sealer. Thirty extracted first mandibular premolars were prepared with a ProTaper Universal system and randomly allocated to three groups. Canals were obturated with gutta-percha and bioceramic root canal sealer, using either single-cone, lateral compaction, or Thermafil filling technique. Each tooth was then scanned with micro-CT. Voids in 2D cross-sectional images and void volumes in 3D images of all root thirds were assessed in relation to obturation technique. There was no significant difference between obturation techniques in the proportion of sections with voids (P > 0.05). However, the results of the obturation techniques significantly differed in relation to root region (P < 0.05). In conclusion, no root filling technique resulted in void-free specimens. Void volumes were highest for the single-cone technique and lowest for Thermafil, in all regions (P < 0.05).

Quantitative volumetric analysis of cross-linked gutta-percha obturators

AIM

The purpose of this study was to evaluate the effects of technique on the filling quality of 2 recently introduced obturation systems comparatively with warm vertical compaction using micro-computed tomography.

METHODS

36 single-rooted teeth were selected, root canals prepared, and assigned to 3 groups (n=12), according to the filling technique: warm vertical compaction technique WVC, GuttaCore (Dentsply Tulsa Dental Specialties, Tulsa, OK) and Gutta Fusion (VDW, Germany). Each specimen was scanned using a micro-CT. Percentage of voids was calculated and data statistically analyzed using Kruskal Wallis test with a significance level of 5%.

RESULTS

All obturations showed satisfactory similar results at the apical level. Differences between the three obturation methods were not significant at 1 mm (-p-value >0.05), 3 mm (-p-value >0.05) and 5 mm (-p-value >0.05). No root fillings were void-free. No significant difference was found between the WVC technique, the GuttaCore technique and the Gutta Fusion technique concerning percentage of apical voids regardless of canal level.

CONCLUSION

This study shows the efficiency of cross-linked obturators in filling root canals hermetically by comparing them to the warm vertical compaction technique. Results show that these obturation techniques were equally sufficient concerning apical adaptation making them appropriate to use in endodontic obturations.

Sealing efficacy of system B versus Thermafil and Guttacore obturation techniques evidenced by scintigraphic analysis

BACKGROUND

This study compared root canal sealing ability, filled by Continuous Wave compaction and two carrier-based obturation systems, using the nuclear medicine approach.

MATERIAL AND METHODS

Fifty-five single-rooted extracted teeth were selected. The crowns were sectioned and each tooth was instrumented using rotary Protaper® Universal system. The roots were divided into 3 experimental groups and two control groups. Forty-five root canals were filled, using Continuous Wave, GuttaCore or Thermafil system and TopSeal sealer. Ten teeth were used as control. On the 7th days the apices were submersed in a solution of sodium pertechnetate 99mTc for 3 hours and the radioactivity was counted.

RESULTS

Although apical leakage in the Continuous Wave group was lower compared with GuttaCore and Thermafil groups, there was no statistical difference (p>0.05).

CONCLUSIONS

System B, GuttaCore and Thermafil techniques showed a similar sealing effect. Key words:Continuous wave compaction, Gutta percha core-carrier, leakage, nuclear medicine.

Evaluation of root canal sealer filling quality using a single-cone technique in oval shaped canals: An In vitro Micro-CT study

The aim of this study was to evaluate and compare the presence of voids in oval root canals filled with different root canal sealers (EndoSequence BC Sealer, Smartpaste bio, ActiV GP) and to compare those with root canals filled with AH Plus sealer using micro-CT. In total, 40 freshly extracted human single-root maxillary premolars were used. Specimens instrumented with the EndoSequence NiTi rotary instrument were assigned randomly into four groups. In each group, root canals were filled with single-cone gutta-percha and one of the tested sealers. Each specimen was then scanned using micro-CT at a voxel resolution of 13.47 μm. Proportions of sections with voids in cross-sectional images and void volumes for each sealer were calculated in the apical, middle, and coronal thirds. Differences according to root canal sealers were evaluated statistically using the Kruskal-Wallis test and the Mann-Whitney U-test at a significance level of 5%. The analysis showed a decrease in void formation in the apical third, with a significant difference between the apical and coronal thirds among bioceramic sealers, ActiV GP, and AH Plus (p < 0.05) but no significant difference between the apical and middle thirds or between the middle and coronal thirds was found for the sealers tested (p > 0.05). All root canal sealers tested resulted in voids. The bioceramic sealers (EndoSequence BC Sealer, Smartpaste bio) produced similar voids which had the fewest in the apical third of root canals among the sealers tested which can be related due to root canal anatomy variations.

Apical filling characteristics of carrier-based techniques vs. single cone technique in curved root canals

OBJECTIVES

In this in vitro study, we assessed filling characteristics (adaptation, homogeneity, sealer percentage, position of the carrier) of warm and cold obturation methods in curved root canals.

MATERIALS AND METHODS

A reciprocating method was used to prepare 90 curved roots (25 ° average curvature) to an apical size of 25.08. They were then obturated with either (A) Guttafusion (VDW, Munich, Germany), (B) Thermafil (Maillefer, Ballaigues, Switzerland) or (C) single cone technique using 25.08 gutta-percha (VDW) and sealer (2Seal easymix) (n = 30 each group). Five sections in 1-mm steps were obtained from each root, beginning 1 mm short of the apex. The percentage of voids in contact with root canal walls (PVO), the proportion of voids per area (PVA) and the percentage of sealer per area (PSA) were measured.

RESULTS

Little to no differences between Guttafusion and Thermafil were seen in curved root canals with respect to adaptation and homogeneity in the apical region. Both methods showed significantly better adaptation and homogeneity than the single cone technique. The proportion of sealer was significantly greater when roots were obturated with Guttafusion than with Thermafil, but both warm obturation techniques had significantly smaller sealer areas than the single cone technique.

CONCLUSIONS

Compared to the single cone technique, a more favourable root canal filling with less sealer could be expected from both warm obturation techniques in curved root canals.

CLINICAL RELEVANCE

The easier-to-handle Guttafusion leads to comparable results as Thermafil in curved root canals.

Comparison of bacterial leakage resistance of various root canal filling materials and methods: Confocal laser-scanning microscope study

This study evaluated the bacterial leakage resistance and root canal lining efficacy of various root canal filling materials and methods by using confocal laser-scanning microscope (CLSM). Sixty extracted human premolars with mature apex and single root canal were randomly divided into 2 control groups and 4 experimental groups. Group CW was filled with continuous wave technique using gutta-percha and AH Plus sealer. Group GC was coated with AH-Plus sealer and then obturated with soften GuttaCore. Group GF was obturated using GuttaFlow and gutta-percha. Group EM was filled with EndoSeal MTA and gutta-percha using ultrasonic vibration. The AH-Plus, GuttaFlow, and EndoSeal were labeled with Hoechst 33342 to facilitate fluorescence. The obturated root tip was incubated with Carboxyfluorescein diacetate succinimidyl ester (CFSE)-stained E. faecalis for 14 days. CLSM was performed to evaluate the sealer distribution and bacterial leakage for the apical 1-, 2-, 3-mm specimens. Statistically significant differences were determined by 1-way ANOVA with Tukey's post-hoc test and Pearson's correlation analysis. Group EM showed the better sealer distribution score than the other groups (p < 0.05). Group CW and group GC exhibited the less bacterial leakage than the group GF, while group EM showed the similar bacterial leakage score with the groups CW and GC. There was no significant correlation between the sealer distribution and bacterial leakage (p > 0.05). Under the conditions of this study, different root canal filling materials and methods showed different efficacy for canal distribution and bacterial leakage resistance.

Quality of obturation achieved by a non-gutta-percha-based root filling system in single-rooted canals

INTRODUCTION

The present study examined the quality of obturation in root canals filled by an experimental non-gutta-percha-based (NGP) root filling system using warm vertical or cold lateral compaction. The quality of obturation was evaluated by comparing the volumetric percentage of gaps and voids identified from similar canals obturated with gutta-percha and an epoxy resin-based sealer using the same obturation techniques.

METHODS

Forty single-rooted premolars with oval-shaped canals were cleaned, shaped, and obturated with 1 of the 4 material/obturation technique combinations (n = 10). Filled canals were scanned with micro-computed tomographic imaging. Reconstructed images were analyzed for the volumetric percentage of gaps and voids at 3 canal levels (0-4, 4-8, and 8-12 mm from the working length). Roots were sectioned at the 4-mm, 8-mm, and 12-mm levels. Scanning electron microscopic images of negative replicas of root sections were examined to quantify the circumferential percentage of interfacial gaps and the area percentage of intracanal voids. Data were analyzed with parametric or nonparametric statistical methods.

RESULTS

A statistically significant difference was found for the volumetric percentage distribution of gaps and voids for "obturation technique" but not for "material." Significantly higher percentages of gaps and voids were identified in canals obturated with the NGP system using cold lateral compaction. Examination of negative replicas ascribed this difference to a higher area percentage of interfacial gaps rather than more intracanal voids.

CONCLUSIONS

Using warm vertical compaction, the NGP system fulfils the objective of 3-dimensional obturation of the canal space in a manner comparable with the results achieved with gutta-percha and a root canal sealer.