Single-cone Technique Research Articles

Long-term sealing ability of GuttaFlow versus Ah Plus using different obturation techniques

To compare the long-term sealing ability of GuttaFlow® using different obturation techniques. Three hundred teeth, prepared with a crown-down technique, were divided into thirty experimental groups (n=10) to evaluate the apical and coronal leakage, at 3, 30 and 120 days, of lateral compaction gutta-percha+AH Plus TM, lateral compaction gutta-percha+GuttaFlow®, single cone+AH Plus TM, single cone+GuttaFlow®, and GuttaFlow® only. Both coronal and apical leakage, at the three times of measurement, no significant differences were found among GuttaFlow®+lateral compaction gutta-percha and GuttaFlow®+single cone groups, whereas the only GuttaFlow® reached the highest leakage values at 30 and 120 days. AH Plus TM, using both techniques, showed high levels of leakage after 120 days to the coronal leakage and after 30 days to the apical leakage when compared silicon based sealer. GuttaFlow®, using with lateral compaction and single cone techniques, shows a greater apical and coronal sealing ability than AH Plus TM over time. GuttaFlow® when used as only creates a poorer sealing when used with lateral compaction gutta-percha or single cone techniques.

An in vitro comparison of coronal and apical sealing ability of mineral trioxide aggregate and gutta percha with sealers

This in vitro study aims to evaluate the coronal and apical sealing ability of gutta percha root filling used with either mineral trioxide aggregate [MTA], calcium hydroxide based sealers, and zinc-oxide eugenol as sealer. Forty single-rooted extracted teeth were selected, decoronated and then instrumented. Samples were randomly divided into three experimental groups. In group 1, root canals were filled using lateral condensation gutta percha technique, with zinc oxide eugenol as a sealer. In group 2, root canals were filled using lateral condensation gutta percha technique with calcium hydroxide based sealer. In group 3, root canals were filled using single cone gutta percha technique in conjunction with MTA. Statistical differences in mean apical dye penetration between the three groups were found. But group 3 showed significantly less coronal dye penetration [p <0.001] as compared to group 1, and group 2. And it was concluded that the single cone technique with MTA can provide favorable coronal and apical seal.

The quality of single cone and laterally compacted gutta-percha fillings in small and curved root canals as evidenced by bidirectional radiographs and fluid transport measurements

The aim of this study was to examine the quality of root fillings in small and curved root canals using bidirectional radiographs and fluid transport (FT) measurements. Root canals in eighty 38 degrees -curved mesial roots of mandibular molars were prepared using a balanced force technique. Samples were divided into 4 groups of 20 each and obturated by either the cold lateral compaction (LC) or the single cone (SC) technique, using either epoxy resin-based or zinc oxide-eugenol sealers. Bidirectional (buccolingual and mesiodistal) radiographs were acquired from each root. The voids along the root filling were assessed. The FT along the root filling was measured using an FT monitoring device. The differences between the groups regarding FT and the bidirectional radiographic score were analyzed by means of a Kruskal-Wallis test. The correlation between the FT values and the radiographic scores were analyzed using a Spearman test. Three groups of LC or SC fillings containing epoxy resin-based sealers exhibited similar radiographic scores and FT values (P > .05). The group of SC fillings that contained zinc oxide-eugenol sealer had worse radiographic scores than the other groups (P = .047). The bidirectional radiographic scores and the FT values for the 80 filled roots were strongly correlated (r(2) = 0.519; P = .00001). Root fillings of similar quality were confirmed in small and curved root canals filled using either a single cone or laterally compacted gutta-percha and epoxy resin-based sealers.

Comparison of the sealing ability of three filling techniques in canals shaped with two different rotary systems: A bacterial leakage study

This study compared the sealing ability of 3 current filling techniques in root canals shaped with 2 different rotary systems. Eighty human extracted mandibular premolars were divided randomly into 2 similar groups of 40 each and instrumented with either ProTaper (Dentsply Maillefer, Tulsa, OK; group A) or Mtwo (VDW; Antaeos, Munich, Germany; group B) rotary systems. Each group was divided into 3 subgroups (n = 10) and 2 control groups (n = 5). Canals were filled either with the tapered single-cone technique (SC; subgroups A1 and B1), with lateral condensation (LC; subgroups A2 and B2), or warm vertical compaction (WVC; subgroups A3 and B3). AH Plus was used as a root canal sealer in all groups. Samples were sterilized in an ethylene oxide sterilizer for 12 hours. The apical 3-4 mm of the roots were immersed in brain-heart infusion culture medium with phenol red indicator within culture chambers. The coronal access of each specimen was inoculated every 48 hours with a suspension of Enterococcus faecalis. Bacterial leakage was monitored every 24 hours for 8 weeks. The data obtained were analyzed using a chi-squared test, and P was set at .05. In group A, 70% of the specimens filled with SC (subgroup A1), 50% of the specimens filled with LC (subgroup A2), and 20% of the specimens filled with WVC (subgroup A3) leaked. There was no statistically significant difference between the subgroups (P > .05). In group B, bacterial leakage was observed in 50% of SC samples (subgroup B1), 40% of LC samples (subgroup B2), and 50% of WVC samples (subgroup B3). There was no statistically significant difference between subgroups B1, B2, and B3 (P > .05). There was also no statistically significant difference between group A and group B (P > .05). Filling with SC, LC, and WVC techniques in canals treated with ProTaper or Mtwo rotary instruments showed similar levels of sealing efficacy.

Graduating Dental Students’ Ability to Produce Quality Root Canal Fillings Using Single‐ or Multiple‐Cone Obturation Techniques

The primary purposes of this study were to compare the quality (length and density) and efficiency (time to completion) of obturation when single- or multiple-cone obturation techniques were used by graduating dental school students on previously instrumented single-canalled teeth using simulated clinical conditions in vitro. Five students took part in the study, each of whom obturated thirty-six teeth using six obturation techniques. The multiple-cone techniques included lateral condensation of gutta-percha, the technique the students had used in their laboratory and clinical courses, and two similar variations: lateral condensation of Epiphany and mechanical lateral condensation of gutta-percha. These three methods were compared to three single-cone techniques: Thermafil, Activ GP, and GuttaFlow. The students had no experience with single-cone techniques except for a brief introduction and demonstration. All obturations were timed, and post-obturation radiographs were taken in the clinical and proximal views (CV and PV). The radiographs were read by two endodontic faculty members who were blinded to technique, student, and fellow faculty member's results. Data were also separated by operator experience with individual techniques: the first three obturations/techniques were compared to the final three obturations/techniques. Data were analyzed using chi-square tests. The quality produced or time required rarely differed within multiple-cone or single-cone groups, but statistical differences did occur between the two groups. Multiple-cone obturation was more likely to produce adequate length (p=0.0042), density in the CV (p=0.0056), and density in the PV (p=0.0003). Conversely, the single-cone techniques were significantly faster (mean 350 seconds) than the multiple-cone techniques (mean 464 seconds) (p=0.0020). Quality did not improve significantly with the experienced groups versus the inexperienced with any of the six techniques, but the mean time for obturation decreased from 449 seconds to 362 seconds. These preliminary findings suggest that further training and experience are needed to improve the quality of obturation produced when single-cone techniques are used. Further research is needed to determine how much training and/or experience will be needed.

Assessment of a new root canal sealer's apical sealing ability

The aim of this study was to investigate the apical sealing ability of a newly introduced root canal sealer: iRoot SP Root Canal Sealer. Sixty-eight extracted human anterior single-root teeth were used. The coronal part of each tooth was removed and the root canals were prepared with ProTaper files. The specimens were divided into 3 groups of 20 teeth each. Group A specimens were filled with iRoot SP using the continuous wave condensation technique; Group B specimens were obturated with iRoot SP using a single cone technique; Group C specimens were filled with AH plus by means of the continuous wave condensation technique. Evaluation of the apical leakage was performed with a fluid filtration method at 24 hours and 1, 4, and 8 weeks. Scanning electron microscopy (SEM) was used to qualitatively assess what mechanisms might be responsible for leakage of the different groups. There was no significant difference in fluid leakage among the groups, as well as no time effect on leakage (P > .05). SEM revealed both gap-free regions and gap-containing regions in canals filled with both materials. iRoot SP was equivalent to AH Plus sealer in apical sealing ability.

Ex‐vivo area‐metric analysis of root canal obturation using gutta‐percha cones of different taper

To evaluate the percentage of gutta-percha and sealer-filled canal area when four different types of master gutta-percha cones were used. Sixty mandibular premolars with straight canals were instrumented using System ProTaper rotary instruments with a crown-down technique and assigned to four groups. Canals were obturated with AH-26 sealer either using lateral condensation and 0.02 taper gutta-percha cones (group A), 0.04 taper gutta-percha cones (group B), nonstandardized F- medium (group C) master gutta-percha cones, or a single System ProTaper gutta-percha cone (group D). The percentage of gutta-percha and sealer-filled area was calculated in horizontal sections of the apical portion of each canal, using image analysis software. The data was statistically analysed using Kruskal-Wallis test. The distribution of filling materials amongst groups was not significantly different at each level of sectioning (P > 0.05). The percentage of gutta-percha and sealer-filled canal area was similar when canals were filled with different master cones using lateral condensation or single cone techniques.

Microleakage evaluation of roots filled with different obturation techniques and sealers

The aim of this study was to compare the apical seal of the Single-cone ProTaper gutta-percha technique and the lateral compaction technique in combination with 3 sealers (AH-26, Apexit, and Sealite-Ultra). Seventy extracted single-root teeth were used. Root canals were prepared with ProTaper rotary instruments. Six groups were formed: (I) Single-cone ProTaper gutta-percha with AH-26; (II) lateral compaction technique with AH-26; (III) Single-cone ProTaper gutta-percha with Apexit; (IV) lateral compaction technique with Apexit; (V) Single-cone ProTaper gutta-percha with Sealite-Ultra; and (VI) lateral compaction technique with Sealite-Ultra. The fluid conductance of each specimen was measured after the 7th and 30th days using a fluid filtration method. When lateral compaction was performed, all sealers showed similar levels of leakage (P > .05). Using the single-cone technique, Sealite-Ultra showed more leakage than the others (P < .05). Comparing filling techniques, there was a significant difference only in the Sealite-Ultra groups (P < .05). Single-cone ProTaper gutta-percha and lateral compaction techniques showed similar sealing effect.

A laboratory assessment of coronal bacterial leakage in root canals filled with new and conventional sealers

To evaluate the resistance to ex vivo bacterial leakage over a 40-day period of root canal fillings with five new root canal sealers: RC Sealer, Epiphany, EndoREZ, GuttaFlow and Acroseal, compared with Apexit, AH Plus and RoekoSeal. One hundred and forty-four single rooted human teeth were divided randomly into eight test (n = 15) and two control groups (n = 12). The root canals were filled using a single cone technique with gutta-percha except in the Epiphany and EndoREZ groups. These were filled with Resilon and resin-coated gutta-percha, respectively. The gutta-percha surface of the GuttaFlow group was coated with an experimental primer prior to filling. Positive controls were filled with gutta-percha without sealer and tested with bacteria, whereas negative controls were sealed with wax to test the seal between the chambers. Filled roots were incorporated in a split chamber model system using Streptococcus mutans as a microbial marker. Leakage was assessed for turbidity of the broth in the lower chamber every day for 40 days. Survival analysis was performed using the Kaplan-Meier product limit method and event times were compared using the Log-rank test (alpha = 0.05). Epiphany, GuttaFlow with test primer and Apexit prevented leakage significantly better than AH Plus, RC Sealer, RoekoSeal, EndoREZ and Acroseal (P < 0.05). None of the specimens in the AH Plus, RC Sealer, RoekoSeal and EndoREZ groups resisted bacterial penetration for 40 days. The new sealers, Epiphany and GuttaFlow with primer, along with Apexit, showed better resistance to bacterial penetration than the other new or traditional sealers tested.

Coronal and apical sealing ability of a new endodontic cement.

This in vitro study aims to evaluate the coronal and apical sealing ability of gutta-percha (GP) root filling used with either mineral trioxide aggregate (MTA), new endodontic cement (NEC) or AH26 as filler/sealers. Forty eight single-rooted extracted teeth were selected, decoronated and then instrumented. Samples were randomly divided into three experimental (n=12) and two control groups (n=6). In group 1, root canals were filled using lateral condensation technique (L); while single cone technique (S) was used for groups 2 and 3. AH26, MTA and NEC were the root canal sealer/fillers in groups 1, 2 and 3, respectively. Samples were immersed in 1% methylene-blue dye and then independently centrifuged apically and coronally. The roots were split longitudinally and linear extent of dye penetration was measured with a stereomicroscope from apical and coronal directions. Data were analyzed using One-way ANOVA and T-test. No statistical differences in mean apical dye penetration between groups LGP/AH26, SGP/MTA and SGP/NEC were found; SGP/NEC group showed significantly less coronal dye penetration (P<0.001). Considering the limitations of this in vitro study, it was concluded that the simple single cone technique with NEC can provide favorable coronal and apical seal.

Comparison of apical and coronal sealing in canals having tapered cones prepared with a rotary NiTi system and stainless steel instruments

The purpose of this study was to compare the sealing ability of different tapered gutta percha cones that were used with lateral compaction and single cones in canals prepared with various root canal instruments. One hundred extracted maxillary incisor roots were used. In group 1, 30 roots were prepared with stainless steel instruments (SS) and then filled by the lateral compaction technique using .02 tapered master cones. In group 2, 30 roots were prepared with ProFile nickel titanium instruments (NiTi) and filled in the same way as group 1. In group 3, 30 roots were filled by the single cone technique using 0.06 tapered gutta-percha cones. The remaining 10 teeth were taken as two control groups. Apical and coronal leakage was evaluated using the fluid filtration model. Considering the effects of the instrumentation, no statistically significant differences were found between the groups prepared with SS and NiTi (P > 0.05). When the effects of obturation technique were taken into consideration, the ProFile instruments and lateral compaction resulted in significantly less coronal leakage than the SS instruments and lateral compaction (P < 0.05). There were no significant differences in apical leakage among any of the groups (P > 0.05).

Resistance of a 4-META–Containing, Methacrylate-based Sealer to Dislocation in Root Canals

The dislocation resistance of root fillings created with MetaSEAL, a self-adhesive 4-META–containing methacrylate resin-based sealer, was evaluated. Forty-six incisors were cleaned and shaped using NaOCl and EDTA as irrigants. They were filled with gutta-percha/MetaSEAL or gutta-percha/AH Plus sealer using either a single-cone technique or warm vertical compaction ( n = 10). The roots were sectioned at the coronal and middle thirds to obtain thin slices, which were subjected to compressive loading to displace the set sealer/filling toward the coronal side of the slice. The remaining six teeth were filled with gutta-percha/MetaSEAL and cryofractured for scanning electron microscopic examination. The push-out strength of AH Plus was significantly higher than MetaSEAL irrespective of filling techniques (p < 0.05). A minimal hybrid layer was seen in radicular dentin, and resin tags were inconsistently identified from canal walls in the MetaSEAL-filled canals. The lower dislocation resistance in MetaSEAL-filled canals challenges the use of a self-adhesive bonding mechanism to create continuous bonds inside root canals.

Long‐term sealing ability of Pulp Canal Sealer, AH‐Plus, GuttaFlow and Epiphany

To evaluate the long-term sealing ability of four contemporary endodontic sealers [Pulp Canal Sealer (PCS), AH-Plus, GuttaFlow and Epiphany] using a fluid filtration technique. The palatal roots of 40 human maxillary molar teeth were selected and the root canal was prepared using a crown-down technique (apical size 40, 6% taper). Roots were irrigated with 3% NaOCl, 17% EDTA solution and rinsed with distilled water. Canals were filled with either PCS, AH-Plus, GuttaFlow or Epiphany using a single-cone technique (n = 8). Twenty-four hours after filling, the roots were connected to an automatic flow-recording device (Flodec System) filled with double-distilled water under pressure (0.2 bar) to measure leakage. Flow rates were assessed at 6, 12 or 24-h and after 1-year of storage. None of the materials fully prevented fluid flow. Fluid flow decreased after 6 h and decreased further after 12 h. After 24 h, PCS and AH-Plus allowed significantly more fluid flow than GuttaFlow and Epiphany. After 1 year, PCS allowed significantly more fluid flow than the other materials. No significant changes in leakage occurred between 24 h and 1 year. GuttaFlow and Epiphany allowed less fluid movement along filled straight roots.

Push‐out bond strengths of the dentine–sealer interface with and without a main cone

To evaluate the push-out bond strength of the dentine-sealer interface with and without main cone for three resin sealers. Thirty extracted maxillary premolar teeth with two separate canals were prepared using 0.04 taper Profile instruments to size 35-45. Teeth were divided into three groups for filling using AH Plus, EndoREZ or Resilon sealers. In each tooth, one canal was filled with a matching single-cone technique, and other was filled with sealer alone. A 1 mm slice of mid-root dentine was prepared for the push-out test. Failure modes after push-out were examined under microscopy and field emission-scanning electron microscopy. Data were analysed using two-way anova and paired t-tests, with significance set at P < 0.05. Overall, the epoxy resin-based sealer provided the highest push-out bond strengths. Push-out bond strengths were significantly higher (P < 0.001) when canals were filled with sealer alone than those filled with main cone and sealer (AH Plus 6.6 and 2.0 MPa, respectively; Resilon 3.4 and 0.4 MPa; EndoREZ 0.9 and 0.4 MPa). Sealers appeared to behave differently as thin films in association with a main cone, compared with bulk material. They failed in cohesive mode within the thin film, leaving a layer of sealer on the canal surface. Bulk sealer showed predominantly adhesive failure at the dentine-sealer interface, with a clean dentine wall and with resin tags either partially pulled out or sheared off at the interface. Push-out bond strengths of resin sealers were much lower when the sealer was present as a thin layer.

An Evaluation of the Sealing Ability of MTA and Resilon: A Bacterial Leakage Study.

The purpose of this study was to evaluate the sealing ability of gray-colored mineral trioxide aggregate (GMTA), white-colored MTA (WMTA), and Resilon as root filling materials. Sixty-six human maxillary central incisors were used in the present study. In the group A, 20 teeth were filled with GMTA. In the group B, 20 teeth were filled with WMTA and in the group C, 20 teeth were filled with Resilon/Epiphany. Three teeth were used as positive (obturated using the single gutta-percha cone technique without sealer) and three were used as negative (obturated with gutta-percha and AH-26 sealer, coated with two layers of nail varnish) controls. A bacterial leakage model utilizing Enterococcus faecalis was used for evaluation. Leakage was noted when turbidity was observed. Controls behaved as expected. In the group A (GMTA) three samples, in the group B (WMTA) four samples, and in the group C (Resilon/Epiphany), two samples were leaked. There was no statistically significant difference between GMTA and WMTA or GMTA and Resilon. In conclusion, sealing ability of GMTA and WMTA was similar to Resilon as orthograde root filling materials.

Auswirkungen der Konizität der Aufbereitung auf die Dichtigkeit von 4 Wurzelkanalfüllmethoden in vitro

The aim of this study was to investigate the influence of the preparation taper on the apical leakage of 4 different root canal obturation techniques. A total of n = 165 human straight teeth roots were divided to groups of 15 each and prepared using rotating Ni/Ti and hand instruments to ISO 40 and tapers of 0.02, 0.04 and 0.06. The roots were filled using a central cone technique, lateral condensation, vertical condensation and continuous wave technique (System-B® and Obtura®). The roots were blinded and coated with nail varnish except 1mm above the apex. After immersion in methylene blue, five sections of 0.8 mm step length were done in the apical region. All roots were then cut at a point 6 mm above the apex. The residual root was then exposed to a second dye immersion. Three serial cuts were done in this middle part of the roots. All cuts were digitised. Penetration depth and penetration degree around the root filling were calculated for the middle part of the root and the apical region separately. Results were compared using MANOVA and a significance level of p = 0.05. There was no influence of taper on penetration depth (p = 0.42), apical penetration degree (p = 0.535) or mid root penetration degree (p = 0.054). We found no influence of the filling method on apical penetration degree (p = 0.141) but highly significant influence on the mid root penetration degree (p < 0.001) and the apical penetration depth (p<0.001). The combination of taper and filling method showed a significant influence on apical penetration degree (p = 0.013) and depth (p = 0.031) but no significant influence in the middle part of the root (p = 0.539). The quality of root canal obturation depends on the combination of preparation taper and filling method. The single cone technique shows best results using a taper of 0.02. For lateral condensation technique a taper of 0.04 seems to be more optimal. Vertical condensation techniques perform independently of the preparation taper. None of the filling methods performed superior to the others.

Leakage of 4 resin-based root-canal sealers used with a single-cone technique

The aim of this study was to measure leakage of 4 resin-based sealers. Four groups of premolars (n = 60) were prepared using GT Rotary files and the crown-down technique and filled by the single-cone technique with AH26, AHPlus, EndoREZ, and an experimental MBP as sealer. Leakage was measured using the fluid filtration method after 15, 30, and 60 days and determined as microL/min(-1) x 10 psi. Statistical analysis by ANOVA and Tukey HSD test indicated that root fillings with AH Plus and the MBP showed lower leakage values after 15 days (P < .05). At 30 days, AH26 presented higher leakage values when compared to other sealers (P < .05). At 60 days, MBP and AH Plus presented the lower leakage values, differing significantly from EndoREZ (P < .05). It was observed that AH Plus and the experimental MBP showed lower leakage after 60 days than AH 26 and EndoREZ.

Sealing properties of two contemporary single‐cone obturation systems

To compare the sealing of root canals filled with two single-cone obturation systems and a warm vertical compaction technique. Forty-two single-rooted teeth were decoronated to obtain 17-mm-long root segments. The root canals were cleaned and shaped to size 40, 0.06 taper and filled with: (i) warm vertical compaction with AH Plus (control); (ii) ActiV GP and (iii) GuttaFlow with single master cones. Leakage was evaluated by fluid filtration at 10 psi before root resection, and after 3, 6, 9 and 12 mm apical resections. Repeated measures anovas on ranks and Dunn's multiple comparison tests were performed to examine differences in fluid flow rates amongst different resection lengths for each filling technique. The surface and interior aspects of glass-ionomer filler-coated ActiV GP gutta-percha cones was evaluated with SEM. No statistical difference amongst the filling techniques was seen at 0 and 3 mm root resections. ActiV GP and GuttaFlow exhibited more leakage than AH Plus at 6, 9 and 12 mm resections. AH Plus recorded the best overall results. A nonhomogeneous coating of glass-ionomer fillers on the surface of ActiV GP cones was detected. The two single-cone techniques examined are as effective in sealing the apex as AH Plus when the latter was used with warm vertical compaction. It is further hypothesized that the inferior coronal seal of these single-cone techniques may be improved with the placement of accessory cones to reduce sealer thickness or an immediate coronal adhesive restoration.

Quality of Molar Root Canal Fillings Performed With the Lateral Compaction and the Single-Cone Technique

The aim was to compare the quality of root canal fillings performed with the single-cone and lateral compaction technique. Thirty-six canals in extracted molars were filled with ISO-standardized gutta-percha points, .02 taper, by using the lateral compaction technique; 38 were filled with one gutta-percha point, .04 taper, by using the single-cone technique. Each root canal was radiographed in the bucco-oral (BO) and the mesiodistal projection (MD). A root was sufficiently filled when three of four observers had assessed it so. There was no significant impact of the filling technique on the quality (logistic regression analysis, p > 0.4). There was a significant impact of the canal type, the mandibular distal canal having a higher chance for a sufficient root filling than the mandibular mesial canal in projection BO (p = .003), but both the mandibular distal (p = 0.001) and the maxillary palatal canals (p = 0.014) had a lower chance for a sufficient filling in projection MD.

Efficacy of Two Contemporary Single-cone Filling Techniques in Preventing Bacterial Leakage

This in vitro study evaluated the sealing efficacy of three root-filling systems/techniques in preventing bacterial leakage. Instrumented single-rooted root segments were filled with (1) warm vertical compaction with gutta-percha/AH Plus; (2) single-cone technique with ActiV GP; and (3) single-cone technique with Gutta-Flow. A dual-chamber leakage model using S. mutans as a microbial marker was used for leakage evaluation. Bacterial penetration was monitored over a 100-day period. Leakage was recorded when turbidity was observed in the lower chamber. Gutta-percha warm vertical compaction exhibited the best seal with bacterial leakage observed in only 16.7% of the specimens between 59 and 100 days. All ActiV GP specimens leaked between 7 and 100 days; 50% of the Gutta-Flow specimens leaked between 22 and 100 days. The two contemporary single-cone techniques did not insure a durable apical seal against bacterial leakage. A warm vertical compaction technique using thermoplasticized gutta-percha and AH Plus sealer appears to be more effective in minimizing bacterial leakage.