Comparison of a warm gutta-percha obturation technique and lateral condensation

Complete Obturation-Cold Lateral Condensation vs. Thermoplastic Techniques: A Systematic Review of Micro-CT Studies

To prevent re-infection and provide a hermetic seal of the root canal system, an endodontist must aim to produce a void-free obturation. This review aimed to compare the completeness of root canal obturation between the two most prevalent methods-cold lateral condensation and warm gutta-percha techniques-using micro-CT (PROSPERO reg no. 249815).

MATERIALS AND METHODS

A search of Scopus, Embase, PubMed (Medline via PubMed), and Web of Science databases was done without any time restriction according to the PRISMA protocol. Articles that compared both techniques and were published in English were included. Data was extracted and the risk of bias was assessed using an adapted tool based on previous studies.

RESULTS

A total of 141 studies were identified by the search. Following the screening and selection of articles, 9 studies were included for review. Data was extracted manually and tabulated. Most studies had a moderate risk of bias. None determined operator skill in both methods before comparison. The data extracted from the included studies suggests that both techniques produce voids in the obturation. The thermoplasticized gutta-percha techniques may result in fewer voids compared to cold lateral condensation.

CONCLUSION

Considering the limitations of the included studies, it was concluded that neither technique could completely obturate the root canal. Thermoplasticized gutta-percha techniques showed better outcomes despite a possible learning bias in favor of cold lateral condensation. Establishing operator skills before comparison may help reduce this bias.

The fate of root canals obturated with Thermafil: 10-year data for patients treated in a master's program

OBJECTIVES

Retrospective description of the 10-year success rate of endodontic treatments with Thermafil (TF).

MATERIALS AND METHODS

Patients treated by postgraduate students in an Endodontics Master's Program (2006-2008) were enrolled. All treated root canals were filled with TF and AH Plus. Teeth satisfying the inclusion criteria (206 teeth in 89 patients) were reexamined clinically and radiographically to estimate a 10-year survival and periapical health. Demographic and medical data were registered; collected information included pre-, intra-, and postoperative variables. Teeth were classified as "healthy" (PAI ≤ 2 in absence of signs/symptoms), "endodontically diseased" (presenting at least one of the following: PAI ≥ 3, signs/symptoms, retreated in the course of the follow-up, or extracted for endodontic reasons), or "non-endodontically diseased" (extracted for non-restorable fractures or periodontal disease). For teeth lost during the 10-year follow-up, details and reason of extraction were analyzed. Two PAI-calibrated examiners assessed outcomes blinded to preoperative status. Bivariate and multilevel analyses were performed (α level set at 0.05).

RESULTS

At 10 years, 179 (87%) teeth survived and 27 were extracted: 20 for non-endodontic reasons (excluded from success analysis) and 7 for endodontic reasons (considered "endodontically diseased"). Multilevel analysis revealed that the probability of extraction was increased by the presence of preoperative pain (odds ratio = 6.720; 95% confidence interval, 1.483-30.448) and by maxillary location (odds ratio = 2.950; 95% confidence interval, 1.043-8.347). Concerning periapical status, 159/186 teeth (85%) were assessed as "healthy." Multilevel analysis confirmed that maxillary location (odds ratio = 3.908; 95% confidence interval, 1.370-11.146), presence of flare up (odds ratio = 9.914; 95% confidence interval, 2.388-41.163), and fracture occurrence (odds ratio = 35.412; 95% confidence interval, 3.366-372.555) decreased the odds of healing, respectively.

CONCLUSIONS

After 10 years, teeth filled with Thermafil in a specialist master's program presented a survival and a periapical health comparable to cohorts where root canals were filled with other obturation techniques.

CLINICAL RELEVANCE

Carrier-based techniques provide time savings for clinicians while satisfying clinical quality criteria for the root filling and consequently the clinical outcome.

Micro-computed tomography assessment of different obturation techniques for filling lateral canals

Background

The aim of this study was to evaluate obturation depth and volume by means of micro-CT when filling lateral canals.

Material and Methods

Thirty single-rooted teeth were used. After instrumentation, three artificial lateral canals were created on each mesial and distal surface (one on each third). The samples were then separated randomly into three groups according to the obturation technique used (n=10): lateral condensation (Group 1), Tagger’s hybrid technique (Group 2) and GuttaCore™ (Group 3). Samples were scanned and data was processed with Avizo software. Depth and volume of the infilling were measured in each lateral canal. Values were expressed as percentages and were analyzed using the Kruskal-Wallis test.

Results

Mean depth showed statistically significant differences between Group 3 and Groups 1 (p=0.001) and 2 (p=0.003), whereas no significant difference was found between Groups 1 and 2 (p≈1). As for mean volume, significant differences were found between Group 3 and Groups 1 (p=0.01) and 2 (p=0.003) but no differences were found between Groups 1 and 2 (p=1.00).

Conclusions

GuttaCore provided the best lateral canal sealing among the three techniques compared.

Key words:Lateral canals, Micro-CT, obturation.

Clinical validation of a nanodiamond-embedded thermoplastic biomaterial

Detonation nanodiamonds (NDs) are promising drug delivery and imaging agents due to their uniquely faceted surfaces with diverse chemical groups, electrostatic properties, and biocompatibility. Based on the potential to harness ND properties to clinically address a broad range of disease indications, this work reports the in-human administration of NDs through the development of ND-embedded gutta percha (NDGP), a thermoplastic biomaterial that addresses reinfection and bone loss following root canal therapy (RCT). RCT served as the first clinical indication for NDs since the procedure sites involved nearby circulation, localized administration, and image-guided treatment progress monitoring, which are analogous to many clinical indications. This randomized, single-blind interventional treatment study evaluated NDGP equivalence with unmodified GP. This progress report assessed one control-arm and three treatment-arm patients. At 3-mo and 6-mo follow-up appointments, no adverse events were observed, and lesion healing was confirmed in the NDGP-treated patients. Therefore, this study is a foundation for the continued clinical translation of NDs and other nanomaterials for a broad spectrum of applications.

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.

Temperature Changes on External Root Surfaces with the Use of Several Thermoplastic Filling Techniques

INTRODUCTION

The purpose of this study was to measure the temperature rise on the external root surface of filled root canals using Touch'n Heat (Analytic Endodontics, Orange, CA), the TC System (TC; Tanaka de Castro & Minatel Ltda, Cascavel, PR, Brazil), and the Tagger technique.

METHODS

Forty-five single-canal mandibular premolar human teeth were used in the 3 experimental groups. The root canals were enlarged to accommodate up to an R40 Reciproc file (VDW, Munich, Germany). Next, the specimens were filled according to the technique evaluated. The measurement of the temperature was performed by K chromium-aluminum thermocouples attached to the coronal, middle, and apical root levels.

RESULTS

There was a significant difference among the 3 techniques (P < .001) in relation to the temperature variation between the highest temperature and the initial temperature. The highest temperature change was found with the Tagger technique at the middle third root level (11.8°C), and the lowest variation was in TC at the cervical third (2.05°C).

CONCLUSIONS

There was a rise of temperature on the external root surface for all of the techniques evaluated. TC showed the lowest temperature rise.

Experimental polyethylene-hydroxyapatite carrier-based endodontic system: an in vitro study on dynamic thermomechanical properties, sealing ability, and measurements of micro-computed tomography voids

The dynamic thermomechanical properties, sealing ability, and voids formation of an experimental obturation hydroxyapatite-reinforced polyethylene (HA/PE) composite/carrier system were investigated and compared with those of a commercial system [GuttaCore (GC)]. The HA/PE system was specifically designed using a melt-extrusion process. The viscoelastic properties of HA/PE were determined using a dynamic thermomechanical analyser. Human single-rooted teeth were endodontically instrumented and obturated using HA/PE or GC systems, and then sealing ability was assessed using a fluid filtration system. In addition, micro-computed tomography (μCT) was used to quantify apparent voids within the root-canal space. The data were statistically analysed using one-way anova and post hoc tests. The HA/PE composite exhibited important modulus and damping changes with an increase of temperature. The HA/PE system was more flexible than GC as the modulus of GC appeared to be significantly higher than that of HA/PE as a result of the high positive glass transition temperature (Tg ). However, HA/PE and GC presented similar sealing abilities. In conclusion, because sealing ability and voids formation were comparable between the tested materials, the experimental HA/PE system may be considered a suitable alternative material for root-canal obturation. Moreover, HA/PE possesses specific viscoelastic behaviour and lower melting points, which may facilitate root-canal retreatments.

Micro-computed tomography analysis of post space preparation in root canals filled with carrier-based thermoplasticized gutta-percha

AIM

To determine whether post space preparation deviated from the root canal preparation in canals filled with Thermafil, GuttaCore or warm vertically compacted gutta-percha.

METHODOLOGY

Forty-two extracted human permanent maxillary lateral incisors were decoronated, and their root canals instrumented using a standardized protocol. Samples were divided into three groups and filled with Thermafil (Dentsply Tulsa Dental Specialties, Johnson City, TN, USA), GuttaCore (Dentsply Tulsa Dental Specialties) or warm vertically compacted gutta-percha, before post space preparation was performed with a GT Post drill (Dentsply Tulsa Dental Specialties). Teeth were scanned using micro-computed tomography after root filling and again after post space preparation. Scans were examined for number of samples with post space deviation, linear deviation of post space preparation and minimum root thickness before and after post space preparation. Parametric data were analysed with one-way analysis of variance (anova) or one-tailed paired Student's t-tests, whilst nonparametric data were analysed with Fisher's exact test.

RESULTS

Deviation occurred in eight of forty-two teeth (19%), seven of fourteen from the Thermafil group (50%), one of fourteen from the GuttaCore group (7%), and none from the gutta-percha group. Deviation occurred significantly more often in the Thermafil group than in each of the other two groups (P < 0.05). Linear deviation of post space preparation was greater in the Thermafil group than in both of the other groups and was significantly greater than that of the gutta-percha group (P < 0.05). Minimum root thickness before post space preparation was significantly greater than it was after post space preparation for all groups (P < 0.01).

CONCLUSIONS

The differences between the Thermafil, GuttaCore and gutta-percha groups in the number of samples with post space deviation and in linear deviation of post space preparation were associated with the presence or absence of a carrier as well as the different carrier materials.

Microscopic assessment of the sealing ability of three endodontic filling techniques

Background

Several techniques have been proposed for root canal filling. New rotary files, with non-standardized taper, are appearing, so, points adapted to the taper of the last instrument used to prepare the canal can help in the obturation process. The aim of this study is to assess the sealing ability of different root canal filling techniques.

Material and Methods

Root canals from 30 teeth were shaped with Mtwo and divided in three groups; A, standard lateral condensation with size 35 and 20 gutta-percha points; B, standard lateral condensation and injected gutta-percha; C, single gutta-percha point (standardized 35 Mtwo), continuous wave technique and injected gutta-percha. Root surfaces were covered with nail varnish, except for the apical 2 mm, and submerged in a NO3Ag2 solution; apical stain penetration was measured in mm. Data were compared using the Kruskal-Wallis test with a 90% confidence interval.

Results

A and B groups showed stain leakage in the 90% of the cases, whereas it was of 80% for group C. Stain leakage intervals were 1-5 mm for groups A and B and 1-3 mm for group C. There were no statistically significant differences between the three studied groups (p>.05).

Conclusions

All the analyzed root canal filling techniques showed some apical stain leakage, without significant differences among them.

Key words:Gutta-percha filling, microleakage, single cone, injected gutta-percha, warm gutta-percha.

A Prospective Randomized Comparative Study of Cold Lateral Condensation Versus Core/Gutta-percha in Teeth with Periapical Lesions

INTRODUCTION

The aim of this study was to compare the outcome of root canal treatment using either Thermafil (TF; Dentsply Maillefer, Ballaigues, Switzerland) or the cold lateral condensation (CLC) obturation technique in teeth with periapical lesions and to investigate the influence on postoperative pain and treatment outcomes.

METHODS

After standardized root canal preparation technique, 112 teeth were obturated with either the TF or the CLC technique during 2 sessions by single operator. Postoperative pain, obturation length, and treatment outcomes were recorded. The teeth were reviewed clinically and radiographically for 2 years.

RESULTS

Although there were no significant differences between the techniques in the incidence of postoperative pain at 24 hours (P > .05), the incidence of pain was significantly higher in the TF group than in the CLC group at 48 hours (P < .05). During the 2-year follow-up period, there was no statistically significant difference in the success rate of the teeth treated with TF (96.4%) in comparison with those treated with CLC (98.2%) (P > .05).

CONCLUSIONS

In this study, the outcome of the root canal treatment of teeth using the TF and CLC techniques revealed that these techniques are useful for root canal obturation.

Nanodiamond-Gutta Percha Composite Biomaterials for Root Canal Therapy

Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes.

Incidence of post-obturation pain after single-visit versus multiple-visit non-surgical endodontic treatments

BACKGROUND

Post-obturation pain is frustrating to both patients and dentists. Its incidence may change with the use of contemporary endodontic techniques. This randomised clinical trial aims to compare the incidence of post-obturation pain at one and seven days after single-visit and multiple-visit non-surgical endodontic treatments.

METHODS

Patients who required primary endodontic treatment in the two clinical trial centres in Hong Kong (HK) and in Beijing (PK) were recruited. Three HK dentists and three PK dentists performed endodontic treatments on 567 teeth using the same procedures and materials, either in a single visit or over multiple visits, using either core carrier or cold lateral condensation for obturation.

RESULTS

The attrition rate was 5.1%, and a total of 538 teeth were evaluated. Among these teeth, 232 (43%) were operated in HK, 275 (51%) were treated in a single visit, and 234 (43%) were treated using core carrier obturation. Logistic regression analysis showed that teeth with apical periodontitis (OR = 0.35, 95% CI = 0.21-0.57, p < 0.01) and less pre-operative pain (OR = 1.10, 95% CI = 1.03-1.18, p < 0.01) had lower incidences of post-obturation pain after one day. The incidences of post-obturation pain after one day for single-visit and multiple-visit treatments were 24.7% (68 of 275) and 33.5% (88 of 263), respectively (p = 0.50). The incidences of post-obturation pain after seven days for single-visit and multiple-visit treatments were 4.0% (11 of 275) and 5.3% (14 of 263), respectively (p = 0.47).

CONCLUSIONS

There was no significant difference in the incidences of post-obturation pain after one day and seven days with single-visit or multiple-visit endodontic treatments.

TRIAL REGISTRATION

ChiCTR-IOR-15005989.

Comparison of single cone obturation performance of different novel nickel-titanium rotary systems

OBJECTIVES

The purpose of this study was to compare several different single-cone obturations in the gutta-percha-filled areas (PGFA), sealer-filled areas (PSFA) and voids, also determining the volumetric characteristics of the tested cones.

MATERIALS AND METHODS

Curved mesial roots of 120 mandibular molars were instrumented using several different systems (ProTaper Next, Twisted File Adaptive, OneShape, ProTaper Universal, WaveOne and Reciproc) and filled with corresponding single cones. The teeth were then sectioned horizontally at 2, 4, 6 and 8 mm from the apex. The area values of each section were calculated and converted to percentages (PGFA, PSFA and voids) of the total area. To determine volumetric characteristics of the tested cones, 20 gutta-percha points of each tested group were scanned with CBCT using the same parameters.

RESULTS

The ProTaper Next and WaveOne groups presented the most PGFA and least PSFA. The Twisted File Adaptive group presented the least PGFA and most PSFA (p < 0.05) and the least gutta-percha volume.

CONCLUSIONS

The Twisted File Adaptive system matched cones had the least volume and the least PGFA in severely curved mesiobuccal canals of mandibular first molars. Single matched cones volume varied.

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

OBJECTIVES

The present study examined the quality of obturation in root canals obturated by GuttaCore, a gutta-percha-based core-carrier system with a cross-linked thermoset gutta-percha carrier, by comparing the incidence of gaps and voids identified from similar canals obturated by cold lateral compaction or warm vertical compaction.

METHODS

Thirty single-rooted premolars with oval-shaped canals were shaped and cleaned, and obturated with one of the three obturation techniques (N=10): GuttaCore, warm vertical compaction or cold lateral compaction. Filled canals were scanned with micro-computed tomography (micro-CT); reconstructed images were analysed for the volumetric percentage of gaps and voids at three canal levels (0-4mm, 4-8mm and 8-12mm from working length). The roots were subsequently sectioned at the 4-mm, 8-mm and 12-mm levels for analyses of the percentage of interfacial gaps, and area percentage of interfacial and intracanal voids, using scanning electron microscopy (SEM) to examine negative replicas of root sections. Data were analysed with parametric or non-parametric statistical methods at α=0.05.

RESULTS

Both micro-CT and SEM data indicated that canals obturated with GuttaCore core-carriers had the lowest incidence of interfacial gaps and voids, although the results were not significantly different from canals obturated by warm vertical compaction. Both the GuttaCore and the warm vertical compaction groups, in turn, had significantly lower incidences of gaps and voids than the cold lateral compaction group.

CONCLUSIONS

Because of the similarity in obturation quality between GuttaCore and warm vertical compaction, practitioners may find the GuttaCore core-carrier technique a valuable alternative for obturation of oval-shaped canals.

CLINICAL SIGNIFICANCE

The quality of obturation achieved by GuttaCore in single-rooted canals is not significantly different from that achieved by warm vertical compaction.

Maxillary premolar with 4 separate canals

INTRODUCTION

Recognition of anatomic variations is a challenge for clinicians regardless of which tooth is treated. Maxillary premolars usually have 2 root canals, but the presence of 3 distinct root canals has been reported in 1%-6% of cases.

METHODS AND RESULTS

This report describes the case of a maxillary right second premolar with 4 separate canals: 1 mesial, 1 palatal, and 2 distal canals. This was confirmed by using cone-beam computed tomography and was successfully treated with rotary files and obturated by using a warm vertical compaction technique.

CONCLUSIONS

The clinical significance of the present case is that this is the first report of 3 roots and 4 separate canals in a maxillary premolar. Precise knowledge of root canal morphology and its variation is also underlined. Cone-beam computed tomography examination and the operating microscope are excellent tools for identifying and managing these complex root canal systems.

An in vitro assessment of gutta-percha coating of new carrier-based root canal fillings

The first aim of this paper was to evaluate the push-out bond strength of the gutta-percha coating of Thermafil and GuttaCore and compare it with that of gutta-percha used to coat an experimental hydroxyapatite/polyethylene (HA/PE) obturator. The second aim was to assess the thickness of gutta-percha around the carriers of GuttaCore and HA/PE obturators using microcomputed tomography (μCT). Ten (size 30) 1 mm thick samples of each group (Thermafil, GuttaCore, and HA/PE) were prepared. An orthodontic wire with a diameter of 0.5 mm was attached to the plunger of an Instron machine in order to allow the push-out testing of the gutta-percha coating. Five samples of (GuttaCore and HA/PE) were scanned using μCT. The data obtained were analysed with one-way analysis of variance and Tukey post hoc test. HA/PE obturators exhibited significantly higher push-out bond strength (P < 0.001) determined at 6.84 ± 0.96 than those of Guttacore around 3.75 ± 0.75 and Thermafil at 1.5 ± 0.63. GuttaCore demonstrated significantly higher bond strength than Thermafil (P < 0.001). μCT imaging revealed that the thickness of gutta-percha around the experimental HA/PE carrier was homogeneously distributed. The bondability and thickness of gutta-percha coating around HA/PE carriers were superior to those of GuttaCore and Thermafil obturators.

Assessment of the sealing abilities of several root canal sealers and filling methods

OBJECTIVE

To evaluate the sealing abilities of two root canal sealers (epoxy resin-based AH Plus(®) and polydimethylsiloxane-based GuttaFlow(®)) and of five root filling techniques (lateral condensation, matched taper single gutta-percha point, laterally condensed-matched taper gutta-percha point, Thermafil(®) and continuous wave of condensation), using a bacterial leakage model.

MATERIALS AND METHODS

One hundred and seventy-four single-rooted human teeth were randomly divided into 10 test groups (n = 15) and two control groups (n = 12). The roots that were filled with the test material, using the different root filling techniques, were mounted in a two-chamber bacterial leakage model and Enterococcus faecalis was added to the upper chambers. The lower chambers of all of the specimens were checked every day during the test period (100 days). The day of turbidity was recorded for each sample. Statistical analysis was performed using the Kaplan-Meier and log-rank tests.

RESULTS

There was no significant difference between the epoxy resin-based and the polydimethylsiloxane-based sealers, irrespective of the filling techniques used (p > 0.05). The continuous wave of condensation technique was found to be superior to the other techniques (p < 0.05). The difference between the other groups was insignificant (p > 0.05).

CONCLUSIONS

AH Plus and GuttaFlow sealers showed similar levels of sealing ability. The continuous wave of condensation technique had the best sealing capability when compared to the other techniques.

Comparative analysis of carrier-based obturation and lateral compaction: a retrospective clinical outcomes study

The purpose of this retrospective study was to compare the outcome of primary endodontic treatment using a standardized cleaning and shaping technique and obturation with either lateral compaction or carrier-based obturation. Patients received primary endodontic treatment in the predoctoral dental clinic using a standardized cleaning and shaping protocol. All root canals were obturated using AH Plus^TM sealer with lateral compaction of gutta-percha (LC) or carrier-based obturation (CBO). A total of 205 cases met the inclusion criteria. 71 teeth in 60 patients were recalled after 2 years and evaluated both clinically and radiographically by two independent examiners. Success was defined as a lack of clinical symptoms and a normal periodontal ligament space or reduction in size of a previously existing periapical radiolucency. Chi-square and logistic regression were used for statistical analysis with a significance level of P < 0.05. There was no difference in success rates between cases obturated with LC or CBO (P = 0.802); overall success rate was 83%. Molars had a significantly lower success rate (53%) than premolar and anterior teeth (89%) (P = 0.005), irrespective of the obturation technique used. When a standardized cleaning and shaping protocol was used by predoctoral dental students in a controlled university setting, there was no difference in success rates between cases obturated with LC or CBO.

Three-dimensional helical computed tomographic evaluation of three obturation techniques: In vitro study

AIM

The purpose of this study was to evaluate the adequacy of three obturation techniques namely lateral condensation, EQ Fil (backfill obturation) and thermafil (core carrier obturation) techniques using three-dimensional (3D) helical computed tomography (CT) by volume rendering method.

MATERIALS AND METHODS

Thirty freshly extracted teeth were randomly divided into three groups of 10 teeth each. Biomechanical preparation was done in all the teeth using rotary instruments. All three sets of teeth were placed in helical CT slice scanner and were imaged before obturation. The three sets were then obturated by following methods: Group I: lateral condensation, Group II: EQ Fil (backfill) and Group III: thermafil (core carrier obturation).Volume of the pulp chamber and gutta-percha after obturation were calculated using volume rendering technique and adequacy of the obturation techniques were calculated.

STATISTICAL ANALYSIS USED

One-way ANOVA and Multiple-Range Tukey Test by Tukey-HSD procedure

RESULTS

Mean change in lateral condensation (0.005±0.002) was significantly higher than that of thermafil obturation (0.002±0.001) [P<0.05].

CONCLUSIONS

Conventional lateral condensation technique showed maximal inadequacy of obturation and thermafil obturation technique showed the least inadequacy of obturation when the volume of the specimens were calculated and reconstructed.

Apical limit of root canal filling and its relationship with success on endodontic treatment of a mandibular molar: 11-year follow-up

OBJECTIVE

This article discusses the relationship between apical limit of root canal filling and success on endodontic treatment of a mandibular molar.

STUDY DESIGN

A mandibular right first molar with vital pulp was endodontically treated, and 3 years later periapical lesions on mesial and distal roots were detected. The canals were retreated and obturated to the same levels as in the previous treatment.

RESULTS

An 8-year radiographic follow-up showed repair of the periapical lesions on both roots.

CONCLUSIONS

Results suggest that the apical limit of obturation seems to have no influence in the repair of periapical tissues in mandibular molars.

Sealing ability of Hybrid Root SEAL (MetaSEAL) in conjunction with different obturation techniques

OBJECTIVE

The objective of this study was to evaluate the apical sealing ability of Hybrid Root SEAL (MetaSEAL) in conjunction with different obturation techniques.

METHODOLOGY

Sixty-eight extracted human mandibular straight single-rooted teeth with mature apices were prepared using a step-back technique and divided into 4 experimental groups (n = 15). An additional 8 teeth were prepared for controls (3 for positive, 3 for negative control, and 2 more for calculating 100% leakage). The experimental groups were obturated with Hybrid Root SEAL (MetaSEAL) using cold lateral condensation, vertical condensation, Thermafil, and Ultrafil techniques. Fluid movement along the filled canals was measured using a fluid filtration method. Measurements were made at 2-minute intervals for 8 minutes. The data were calculated as microL/min and statistically analyzed using 1-way ANOVA and Duncan Test.

RESULTS

Cold lateral and vertical condensation had significantly less fluid movement than the Thermafil and Ultrafil groups. Thermafil group had the highest fluid movement values when compared with the other groups (P < .01).

CONCLUSION

Hybrid Root SEAL (MetaSEAL) had less fluid movement with cold lateral and vertical condensation techniques when compared with Thermafil and Ultrafil techniques.

Evaluation of the thermoplasticity of different gutta-percha cones and the TC system

Objective:

The aim of this study was to evaluate the thermoplasticity of three commercial brands of gutta-percha (Tanari, Dentsply 0.06, and Roeko), and of the TC system.

Materials and Methods:

Standardized specimens were fabricated from the materials to be evaluated. Specimens were placed in water at 70°C for 60 seconds. Following that, they were positioned between two glass slabs and each set was compressed by a 5kg weight. Images of the specimens before and after compression were digitized and analyzed by the Image Tool software. The flow capacity of each material was confirmed by the difference between the initial and final areas of each sample.

Results:

The resulting data were analyzed by ANOVA. The TC system presented the greatest thermoplasticity values (p<0.05). Among the gutta-percha cones, the Roeko brand showed higher thermoplasticity than the others (p<0.05).

Conclusion:

The gutta-percha from TC system present good thermoplasticity capacity.

Root Canal Treatment Using Thermoplasticized Carrier Condensation Technique

BACKGROUND

The management of pulpally and apically infected teeth has evolved into a modality of conservation with predictable degree of success. Root canal treatment often requires protracted chairside time. A new technique involving placement of thermoplasticized core carrier obturators was compared with conventional lateral condensation technique.

METHODS

A prospective, comparative, in-vivo cohort study was carried out on randomly selected 100 patients visiting a tertiary care centre from July 2005 to July 2007, for primary, non-surgical conservative management of teeth requiring root canal treatment. Two groups of fifty cases each were managed with lateral condensation and thermoplasticized core carrier obturation techniques. Outcome variables were rate of obturation and failure rates as assessed by clinical and radiological evaluation.

RESULT

The time taken in case of lateral condensation of maxillary central incisor was 17.30 ± 3.373 minutes and 28.07 ± 2.586 minutes in case of mandibular molar. In the thermoplasticized carrier condensation technique, for the central incisors it took 13.00 ± 1.376 minutes and 21.07 ± 2.463 minutes for mandibular molars. The mean rank value for time taken for obturation as per Mann Whitney U test (p < 0.01) were 27.88 for maxillary incisor and 44.73 for mandibular molar in the lateral condensation technique and 13.13 and 16.27 respectively for thermoplasticized gutta percha carrier condensation. The values were statistically significant. With 16% and 14% cases having unsatisfactory filling as evaluated by post filling radiograph, Chi square test two tailed p value was 0.6836 and there was no statistically significant difference between the two groups. An absolute failure rate of 10% was seen in lateral condensation group and 6% in thermo-plasticized carrier condensation group. Fisher exact 2-tailed p value was 0.71 and the difference in failure rate was not statistically significant.

CONCLUSION

Root canal obturation by thermoplasticized core carrier condensation technique is an effective alternative to conventional lateral condensation technique in terms of quick and successful outcome.

Technique acquisition in the use of two thermoplasticized root filling methods by inexperienced dental students: a microcomputed tomography analysis

INTRODUCTION

Limited endodontic experiences in dental schools suggest the need for easy-to-learn techniques. Therefore, two simplified root filling methods were assessed for adequacy and expediency when performed by inexperienced students.

METHODS

Eight students were trained (45-minute lecture and 90-minute practice) in use of ProTaper Obturators (PTO) and System-B/Calamus (SBC). They subsequently filled the root canals in two extracted, single-rooted teeth per method (n = 32). Canals were preshaped and prefitted with obturators and master cones. The volume of root-filling voids determined by microcomputed tomography imaging in 1-mm increments, time to complete fillings, and students' responses in questionnaires were analyzed (independent-sample t test and Mann-Whitney U test).

RESULTS

PTO had a significantly smaller void volume in the apical 6 mm of canals (P < 0.001), required significantly shorter time (P < 0.001), and was perceived as easier to learn and use but less likely to be favored after graduation than SBC.

CONCLUSION

These results suggested that the PTO root filling method was particularly suitable for teaching when endodontic experiences available for students are limited.

[Not Available]

The Authors describe two cases of alleged malpractice due to overfilling. The aim of this article is to underline some medico-legal aspects regarding the quantity of extruded material which may be considered acceptable and the consequent damage to the patient.

Two cases are presented here: In the first case, the dentist’s liability is clear due to excessive extrusion of endodontic material beyond the apical region combined with incomplete obturation of the canals. In the second case however, because two different dentists were involved, establishing the connection of causality between their work and the damage reported by the patient was not easy. This situation makes it difficult to establish the limits of potential responsibility, coupled with the complete absence of radiographic signs of periapical rarefaction and the small quantities of material beyond the apex. From a medico-legal point of view, a dentist may be held responsible for compensation and financial expenses of a patient for restoration of damage resulting from a dental procedure.

Italian guidelines offer no indications as to when overfilling should be considered the result of a procedural error, or if it fits within the range labelled as “acceptable” and this gap offers extremely subjective interpretations of legal consultants. So, it would therefore be useful to adopt more precise qualitative/dimensional parameters, keeping in mind that the guidelines offer therapeutic recommendations and are not rigid protocols.

Leakage evaluation of three different root canal obturation techniques using electrochemical evaluation and dye penetration evaluation methods

The aim of this study was to compare the apical sealing ability of three different obturation techniques using an electrochemical evaluation and evaluating dye penetration. One hundred and thirty-two maxillary anterior teeth were randomly divided into six groups. There were 20 teeth in each group. The teeth were obturated as follows: Groups 1 and 4 with Thermafil, Groups 2 and 5 with System B, and Groups 3 and 6 with cold lateral condensation (CLC). The apical leakage in these groups was evaluated using an electrochemical method for Groups 1, 2, 3 and a dye penetration method for Groups 4, 5 and 6. In both methods, the lowest mean leakage values were observed for Thermafil and the highest were observed for the CLC groups. The difference between Thermafil and CLC was statistically significant (P < 0.05). In both groups, System B fillings showed moderate leakage and the difference was not significant with Thermafil and CLC groups.

Evaluation of the thermoplasticity of different gutta-percha cones and Resilon�

The goal of this study was to evaluate the thermoplasticity of conventional and thermoplastic gutta-percha and Resilon, a polyester polymer-based material. Specimens with standardised dimensions were made from the following materials: conventional and thermoplastic gutta-percha (Dentsply), conventional and thermoplastic gutta-percha (Endopoints) and Resilon. After 24 h, the specimens were placed in water at 70 degrees C for 60 s, and thereafter positioned between two glass slabs. Each set was compressed by a 5-kg weight. Digital images of the specimens before and after compression were obtained and analysed. The thermoplasticity of each material was confirmed by the difference between final and initial areas of each sample. The data were analysed statistically by anova and Tukey's test at a 5% significance level. Resilon had the highest thermoplasticity means (P < 0.05). Among the gutta-percha cones, Endopoints TP (thermoplastic) presented the highest thermoplasticity means and differed significantly from the other commercial brands (P < 0.05). Resilon had good thermoplasticity, endorsing its use as a thermoplastic root canal filling material.

Negative influence of continuous wave technique on apical sealing of the root canal system with Resilon

The aim of this study was to investigate apical microleakage after use of the Resilon system in comparison with gutta-percha. The materials used were 54 mesial roots of mandibular molars with an apical curvature of 20-40 degrees . The root canals were instrumented with the Prosystem GT(R) and obturated with: Group I: Gutta-percha + Sealer by lateral condensation (n = 25); Group II: Gutta-percha + Sealer, complemented by System B and Obtura II (n = 25); Group III: Resilon + System B and Obtura II (n = 25); Group IV: Resilon by lateral condensation (n = 25). After immersion in India ink, the specimens were demineralized and rendered transparent. Apical dye leakage was analyzed with a stereomicroscope and a digital camera connected to a computerized system. All groups showed different degrees of apical dye microleakage. The Kruskal-Wallis test revealed that the largest leakage occurred in Group I (P < 0.05), whereas the other groups presented a similar pattern of microleakage (P > 0.05). Thermoplastification negatively influenced the apical sealing ability of Resilon. Gutta-percha points and conventional sealer yielded the highest values of apical leakage, especially when the lateral condensation technique was used. Regardless of the obturation technique employed, the Resilon system provided the lowest mean values of apical leakage, but did not provide hermetic sealing of the root canal system.

A comparison of 5 gutta-percha obturation techniques to replicate canal defects

OBJECTIVE

The purpose of this study was to compare the ability of five different methods of compaction of thermoplasticized GP to replicate four artificially-created defects in the canal walls of an extracted tooth. One of the instruments tested was the EndoTwinn which was recently introduced to the U.S. market and can be used in both the warm lateral (WLC) and warm vertical compaction (WVC) techniques.

STUDY DESIGN

Four artificially-created defects were created in the dentinal walls of a split-tooth model which could be separated after each obturation and the obturation mass removed for visual evaluation. Twenty obturations were evaluated for each of the following techniques: Group 1, WLC without vibration using the EndoTwinn; Group 2, WLC with heat and vibration using the EndoTwinn; Group 3, WVC using the Elements Obturation System (EOS); Group 4, Injectable GP using the EOS; and Group 5, WVC using the EndoTwinn. Kruskal-Wallis statistic was used to determine statistically significant differences, pairwise comparisons were analyzed with the Mann Whitney statistic and a Bonferonni adjustment was made, where indicated.

RESULTS

Nonparametric analyses with appropriate Bonferroni adjustments indicated statistically significant results favoring Groups 2 and 4.

CONCLUSIONS

The EndoTwinn, in heat and vibration mode, and the EOS resulted in better replication of the defects than the other techniques.

An ex vivo comparison of three different gutta-percha cones when compacted at different temperatures: rheological considerations in relation to the filling of lateral canals

AIM

To compare ex vivo the penetration of three brands of gutta-percha cones, compacted under a constant force and heated to different temperatures, into artificial lateral canals.

METHODOLOGY

Resin blocks with simulated main canals, each having two lateral canals (C at 6.5 and A at 13 mm from the surface of the resin block), were selected. A gutta-percha cone, either Mynol MF, Hygenic MF or GT Tulsa 0.04 was compacted into each main canal for 5 s using a wire rod with a diameter of 0.7 mm soldered to the bottom of a metal cylinder, with a force of 2.7 kg at controlled temperatures of 37, 42, 47, 52, 60 degrees C. The penetration of each brand of gutta-percha into 60 lateral canals (10 at each temperature) was measured using a stereomicroscope. Statistical analysis was performed using the ANOVA, the Scheffè test and the t-test.

RESULTS

None of the three brands of cones entered up to 0.1 mm within either lateral canal until a temperature of 47 degrees C was reached; at that temperature only Mynol cones (P < or = 0.05) penetrated in four of 10 A-level canals (mean 0.13 +/- 0.19 mm) and in all 10 C-level canals (mean 0.43 +/- 0.12 mm). The A-level lateral canals were penetrated at 52 degrees C by Mynol cones (mean 0.76 +/- 0.34 mm) to a significantly greater distance (P < or = 0.05) than Tulsa cones (mean 0.31 +/- 0.12 mm) and Hygenic cones (mean 0.11 +/- 0.08 mm). At 60 degrees C the Mynol cones (mean 1.93 +/- 0.34 mm) penetrated significantly more (P < or = 0.05) than the Tulsa cones (mean 0.86 +/- 0.22 mm) and Hygenic cones (mean 0.67 +/- 0.19 mm). The C-level lateral canals were penetrated at 52 degrees C by Mynol cones (mean 0.91 +/- 0.29 mm) to a significantly greater distance (P < or = 0.05) than Tulsa cones (mean 0.47 +/- 0.16 mm) and Hygenic cones (mean 0.46 +/- 0.15 mm), whilst no significant difference was found at 60 degrees C.

CONCLUSIONS

When heated and compacted, the three gutta-percha cones penetrated the lateral canals to different degrees. They penetrated more than 0.43 mm into the lateral canals only at temperatures higher than 47 degrees C.

A comparison of three gutta-percha obturation techniques to replicate canal irregularities

A split-tooth model with artificially created intracanal wall defects was used to compare three gutta-percha (GP) obturation techniques, cold lateral, warm lateral, and warm vertical. The techniques were evaluated and compared based on defect replication quality as a function of defect location and size. The obturations were evaluated on an ordinal scale, 0 to 4, based on how much each defect was replicated. There was a statistically significantly better result with both warm techniques compared to cold lateral obturation, while there was no significant difference between the warm obturation techniques.

An In Vitro Model to Investigate Filling of Lateral Canals

Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group 1 were filled with Schilder's technique, canals of group 2 were filled with vertical compaction with apical backfilling. Stereomicroscopic analysis of lateral canal filling revealed lower filling rates in apical canals compared to coronal ones and higher filling rates with "vertical compaction with apical backfilling" compared to Schilder's group. The tested procedure appears to be a reliable technique to obtain standardized lateral canals and to compare filling procedures.

The imaging of root canal obturation using micro-CT

AIM

To examine the potential and accuracy of micro-computed tomography (micro-CT) for imaging of filled root canals.

METHODOLOGY

The root canals of five extracted maxillary teeth were shaped manually with K-files. After irrigation and drying, the root canals were filled by lateral condensation using gutta-percha cones and AH plus (Dentsply Maillefer, Ballaigues, Switzerland) as sealer. The filled root canals were examined by micro-CT at resolutions <11 microm. Three-dimensional reconstructions of the root canal fillings were made. The roots were sectioned histologically and standard photographs of the sectioned surfaces were taken. Digitized photographic images and the corresponding micro-CT sections were correlated qualitatively by superimposition. Quantitative morphometric data were obtained with respect to the surface area of the root canal filling and the individual gutta-percha points of the histological and the micro-CT sections. Pearson correlation coefficients were calculated.

RESULTS

There was a good qualitative correlation between the images from the histological and the micro-CT sections. The fillings were clearly differentiated from the root canal walls. Individual gutta-percha cones and sealer were discernable. Pearson correlation coefficients showed a highly significant correlation between the two methods (P < 0.001) with respect to the area of the complete root canal filling (r = 0.992) and the gutta-percha cones (r = 0.968).

CONCLUSIONS

The micro-CT technique was a highly accurate and nondestructive method for the evaluation of root canal fillings and its constituents. Qualitative and quantitative correlation between histological and micro-CT examination of root canal fillings was high.