The sealing ability of GuttaFlow in oval-shaped canals: an ex vivo study using a polymicrobial leakage model

Volume and power of expansion of novel polyurethane-based sealers

INTRODUCTION

Shrinkage and lack of interfacial adaptation between endodontic sealers and root canal walls may jeopardize the root canal treatment outcome. This study aimed to evaluate the volume and power of expansion (and the relationship between the two) of three novel root canal sealers (polyurethane expandable sealer (PES), zeolite + PES (ZPES), and elastomeric polyurethane sealer (EPS)) in comparison with an epoxy-resin based sealer (AH Plus) and a calcium silicate-based sealer (EndoSequence BC).

METHODS

This study utilized 36 cylinders (30 plastic graduated cylinders for volume of expansion and 6 steel cylinders for power of expansion) (4x10mm) filled with PES, ZPES, EPS, AH Plus, EndoSequence BC, or water (n=5/group). The plastic graduated cylinders were inserted inside a customized Linear Swell Meter (LSM) apparatus to measure the percentage of volumetric expansion. The steel cylinders were placed inside an LSM apparatus mounted onto a universal testing machine to measure the maximum pressure in psi. Specimens were tested for 72 hours for both volume and power of expansion tests. Data were analyzed using Kolmogorov-Smirnov, one-way ANOVA, Post Hoc Tukey, and Pearson correlation tests (p<0.05).

RESULTS

The volume of expansion of PES, ZPES, and EPS was significantly higher than in AH Plus and EndoSequence BC (p<0.05). For the power of expansion, no significant differences were found between the root-filling materials (p>0.05). No correlation was seen between the volume and power of expansion (p>0.05).

CONCLUSION

Although polyurethane-based sealers showed a significantly higher volume of expansion compared to AH Plus and EndoSequence BC, their power of expansion did not increase significantly.

Comparison of Sealing Ability of Bioceramic Sealer, AH Plus, and GuttaFlow in Conservatively Prepared Curved Root Canals Obturated with Single-Cone Technique: An In vitro Study

Background:

Inadequate obturation techniques of the root canal system have been found to be the most frequent reason of failure post root canal treatment. An ideal endodontic sealer should fulfill all ideal requisites. The present study aimed to compare apical sealing ability between bioceramic (BC) sealer, GuttaFlow, and AH Plus.

Methodology:

One hundred and twenty-five curved roots of maxillary and mandibular third molar teeth with fully formed apex were collected for this study. The root canals were cleaned and shaped using a standard single-cone preparation to file at the established working length and divided into five groups of 25 each. Dye leakage was carried out. Group A: with GP, using EndoSequence BC sealer with conventional with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group B: with ceramic coated with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group C: with GP, using AH Plus sealer (Dentsply, De-Trey Konstanz, Germany) with 4% gutta-percha; Group D: with GuttaFlow bioseal (Roeko-Coltène/Whaledent, Langenau, Germany) with 4% Gutta-percha; and Group E is a negative control group. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.

Results:

The group AH Plus showed more leakage values than the GuttaFlow group and of two groups of BC sealer and negative control. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.

Conclusion:

None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal.

Comparison of bacterial microleakage of three bioactive endodontic sealers in simulated underwater diving and aviation conditions

BACKGROUND

Bacterial microleakage is an important cause of apical periodontitis and endodontic treatment failure. This study aimed to assess the bacterial microleakage of nano-mineral trioxide aggregate (nano-MTA) as a sealer, Endoseal MTA, and GuttaFlow Bioseal sealers in atmospheric pressure, and simulated underwater diving and aviation conditions.

METHODS

In this in vitro, experimental study, 180 extracted single-rooted teeth were cleaned and shaped, and were then randomly divided into three groups for single-cone obturation using Endoseal MTA, GuttaFlow Bioseal, or nano-MTA as a sealer. Each group was then randomly divided into three subgroups, and subjected to ambient atmospheric pressure, 2 atm pressure (to simulate underwater diving), and 0.5 atm pressure (to simulate aviation) using a custom-made pressure chamber. The teeth then underwent microbial leakage test using Streptococcus mutans (S. mutans), and the percentage of samples showing microleakage was recorded for up to 1 month, and analyzed using the Chi-square test.

RESULTS

The three sealer groups were significantly different regarding bacterial microleakage (P < 0.05). The nano-MTA group showed significantly higher microleakage after 15 days than the other two groups (P = 0.006). The effect of pressure on bacterial microleakage was not significant in any sealer group (P > 0.05).

CONCLUSION

Within the limitations of this in vitro study, it may be concluded that single-cone obturation technique using nano-MTA as a sealer results in lower resistance to bacterial microleakage compared with the use of GuttaFlow Bioseal, and Endoseal MTA. Pressure changes in simulated underwater diving and aviation conditions had no significant effect on bacterial microleakage. Trial Registration Number This is not a human subject research.

A Novel Polyurethane Expandable Root Canal Sealer

INTRODUCTION

Endodontic sealers play a vital role in the obturation of root canal space. The aim of this study was to evaluate the utility of a recently developed polyurethane expandable sealer (PES), along with its cytotoxicity and dimensional changes.

METHODS

L929 fibroblasts and an cell viability assay (MTS assay) were used to determine the cytotoxicity of dental sealers (AH Plus [Dentsply Maillefer, Ballaigues, Switzerland], Sure-Seal Root [Sure Dent Corporation, Gyeonggi-do, South Korea], and the PES) at 24, 48, 72, and 96 hours. An advanced choroidal neovascularization model was used to assess the effect of these sealers on angiogenesis. Thirty-six extracted single-rooted human teeth were prepared and randomly divided into 3 groups (n = 12). Obturation was performed with gutta-percha and a sealer using lateral compaction as follows: group 1, AH Plus; group 2, Sure-Seal; and group 3, PES. The average depth of sealer penetration into dentinal tubules was measured with a scanning electron microscope. Data were analyzed using 1-way analysis of variance and post hoc Tukey tests (level of significance, P < .05).

RESULTS

The values of MTS, choroidal neovascularization, and the penetration depth of PES were significantly higher than in other experimental groups (P < .05). The lowest values were noted in specimens of AH Plus, whereas the highest were detected in the PES group.

CONCLUSIONS

PES showed promising results in terms of biocompatibility and dentinal tubule adaptation and penetration.

Applications of Silver Nanoparticles in Dentistry: Advances and Technological Innovation

Silver nanoparticles (AgNPs) have been successfully applied in several areas due to their significant antimicrobial activity against several microorganisms. In dentistry, AgNP can be applied in disinfection, prophylaxis, and prevention of infections in the oral cavity. In this work, the use of silver nanoparticles in dentistry and associated technological innovations was analyzed. The scientific literature was searched using PubMed and Scopus databases with descriptors related to the use of silver nanoparticles in dentistry, resulting in 90 open-access articles. The search for patents was restricted to the A61K code (International Patent Classification), using the same descriptors, resulting in 206 patents. The results found were ordered by dental specialties and demonstrated the incorporation of AgNPs in different areas of dentistry. In this context, the search for patents reaffirmed the growth of this technology and the dominance of the USA pharmaceutical industry over AgNPs product development. It could be concluded that nanotechnology is a promising area in dentistry with several applications.

Comparative evaluation of push-out bond strength of gutta-percha using different sealers with lateral condensation and thermoplasticized obturation technique: An in vitro study

Aim:

The study aimed to evaluate and compare the push-out bond strength of gutta-percha using AH plus, Endosequence BC, and Roeko seal sealer with lateral condensation and thermoplasticized obturation technique.

Materials and Methods:

Sixty single-rooted premolars were instrumented and samples were randomly assigned into three groups based on the sealer used (Group A-AH Plus, Group B-Endosequence BC, Group C-Roeko Seal) which were further divided into two subgroups-A1, B1, and C1 were obturated by the lateral condensation technique and A2, B2, and C2 using the thermoplasticized technique. Each sample was sectioned horizontally using a diamond disc, representing apical, middle, and coronal thirds, respectively. Root segments were then mounted on an acrylic block, and push-out bond strength of each sample was tested using the universal testing machine.

Statistical Analysis:

One-way ANOVA, Tukey's test, and unpaired t-test.

Results:

For mandibular premolar teeth with a single canal using lateral condensation technique, the highest push-out bond strength was found in the A1 group (7.30 ± 0.61 MPa) at the apical level. While using the thermoplasticized technique, the highest push-out bond strength was found in the B2 group (3.71 ± 0.81 MPa) at the apical level. Overall results showed that the lateral condensation technique showed significantly higher push-out bond strength than thermoplasticized technique (P < 0.028).

Conclusions:

The push-out bond strength of AH Plus sealer was higher than the Endosequence BC sealer and Roeko seal sealer. Lateral condensation technique has shown higher push-out bond strength than the thermoplasticized technique.

Sealing Ability of AH Plus and GuttaFlow Bioseal

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

Assessment of cell viability in four novel endodontic sealers

Objective

The aim of this study was to evaluate the viability of human periodontal ligament (PDL) cells on MTA-Fillapex, GuttaFlow 2, TotalFill Sealer, and BioRoot™ RCS in comparison to conventional epoxy resin-based (AH Plus) and zinc oxide-eugenol-based (Roth's 801) sealers.

Materials and Methods

Sealers were divided into two groups, and five coverslips for each material per group were prepared. In the first group, PDLs were added immediately after the preparation of sealers (Fresh Group), and in the second, PDLs were added after 24 h. PDLs were cultured for 72 h and afterward, counted using standard hematocytometry. A Mann-Whitney U-test and Kruskal-Wallis test were used for the statistical analysis. The level of significance was set at 5%. Furthermore, cell morphology was assessed by confocal microscopy.

Results

The number of viable cells for the 24 h-set groups was higher than the freshly mixed in all sealers except Roth's 801. In both groups, GuttaFlow 2 presented the highest number of viable cells. In a descending order of cells' survival, TotalFill, BioRoot, and MTA-Fillapex are following and the conventional sealers, AH Plus and Roth's 801, seem not to exhibit the biological properties of the others. Cells grown on GuttaFlow 2, TotalFill, and BioRoot were observed to be well-formed. In contrast, MTA-Fillapex exhibited untypical morphology. No cells were detected on the surfaces of AH Plus, as well as Roth's 801.

Conclusions

All novel sealers presented increased cell viability in comparison to conventional sealers. GuttaFlow 2 exhibited the highest cell viability.

The push out bond strength of polydimethylsiloxane endodontic sealers to dentin

Background

The purpose of this experiment was to assess the push out bond strength of Polydimethylsiloxane sealers (GuttaFlow 2 and GuttaFlow Bioseal by Colte’ne/Whaledent, Altstätten, Switzerland). AH Plus (Dentsply, DeTrey, Konstanz, Germany) was used as a reference material for comparison.

Methods

Thirty root slices were prepared from the middle third of 10 mandibular premolars. Each slice was 1 ± 0.1 mm thick. Three holes, 0.8 mm wide each, were drilled on the axial side of each root slice. These holes were subjected to standardized irrigations and then dried using paper points. Finally, for each root slice, each hole was filled with exactly one of the following three root canal sealers: AH Plus, GuttaFlow 2 and GuttaFlow Bioseal. After all the holes were filled in that way, the root slices were stored on top of phosphate-buffered saline solution (pH 7.2) soaked gauze for 7 days at the temperature of 37 degrees Celsius. Then, for each root canal sealer on a root slice, the universal testing machine was used to measure the push out bond strength. The differences in push out bond strengths between the three sealer samples were assessed using the Friedman test, while the paired comparisons were assessed using Wilcoxon signed rank test with Bonferroni correction. All statistical tests were two-tailed and the significance level was set at the 5%.

Results

According to the Friedman test the distributions of push out bond strengths of AH Plus, GuttaFlow 2 and GuttaFlow Bioseal were different (P < 0.05). Paired comparisons indicated that AH Plus had a significantly superior push out bond strength than GuttaFlow 2 and GuttaFlow Bioseal, while the push out bond strength of GuttaFlow Bioseal was significantly stronger than that of GuttaFlow 2 (P < 0.01).

Conclusions

Based on these findings, AH Plus is a better root canal sealer than GuttaFlow 2 and GuttaFlow Bioseal.

The implications and applications of nanotechnology in dentistry: A review

The emerging science of nanotechnology, especially within the dental and medical fields, sparked a research interest in their potential applications and benefits in comparison to conventional materials used. Therefore, a better understanding of the science behind nanotechnology is essential to appreciate how these materials can be utilised in our daily practice. The present paper will help the reader understand nanoscience, and the benefits and limitations of nanotechnology by addressing its ethical, social, and health implications. Additionally, nano-applications in dental diagnostics, dental prevention, and in dental materials will be addressed, with examples of commercially available products and evidence on their clinical performance.

Investigations into in situ Enterococcus faecalis biofilm removal by passive and active sodium hypochlorite irrigation delivered into the lateral canal of a simulated root canal model

AIM

To investigate in situ Enterococcus faecalis biofilm removal from the lateral canal of a simulated root canal system using passive or active irrigation protocols.

METHODOLOGY

Root canal models (n = 43) were manufactured from transparent resin materials using 3D printing. Each canal was created with an 18 mm length, apical size 30, a .06 taper and a lateral canal of 3 mm length, with 0.3 mm diameter. Biofilms were grown in the lateral canal and apical 3 mm of the main canal for 10 days. Three models from each group were examined for residual biofilm using SEM. The other forty models were divided into four groups (n = 10). The models were observed under a fluorescence microscope. Following 60 s of 9 mL of 2.5% NaOCl irrigation using syringe and needle, the irrigant was either left stagnant in the canal or activated using gutta-percha, sonic or ultrasonic methods for 30 s. Images were then captured every second using an external camera. The residual biofilm percentages were measured using image analysis software. The data were analysed using generalized linear mixed models. A significance level of 0.05 was used throughout.

RESULTS

The greatest level of biofilm removal was obtained with ultrasonic agitation (66.76%) followed by sonic (45.49%), manual agitation (43.97%) and passive irrigation groups (38.67%), respectively. The differences were significant between the residual biofilm in the passive irrigation and both sonic and ultrasonic groups (P = 0.001).

CONCLUSION

Agitation resulted in better penetration of 2.5% NaOCl into the lateral canal of an artificial root canal model. Ultrasonic agitation of NaOCl improved the removal of biofilm.

Epoxy Resin-Based Root Canal Sealer Penetration into Dentin Tubules Does not Improve Root Filling Dislodgement Resistance

Objective:

This study sought to evaluate the effect of the penetration of an epoxy resin-based root canal sealer into dentin tubules on the force required to dislodge the root canal filling.

Methods:

Sixty extracted human central incisors with single canals were decoronated, instrumented, and filled with gutta-percha and AH Plus sealer labeled with 0.1% rhodamine B dye. The roots were further sectioned horizontally at 3, 6, and 8 mm from the apex. The coronal surfaces of the resulting 180 slices were evaluated using confocal laser scanning microscopy to measure the amount of sealer that penetrated into the dentin tubules. To quantify the force required to dislocate the root filling material, the root fillings of the slices were subjected to a dislodgement resistance test (push-out). Spearman’s rho correlation test was further used to test the correlation between the push-out bond strength and sealer penetration into the dentin tubules (P<0.05).

Results:

No significant correlation was observed between sealer penetration into the dentin tubules and the force required to dislodge the root canal filling (P=0.626).

Conclusion:

Following the results of this study, the penetrating ability of the AH Plus sealer into dentin tubules has no correlation with the force required to dislodge the root canal filling.

Confocal laser scanning, scanning electron, and transmission electron microscopy investigation of Enterococcus faecalis biofilm degradation using passive and active sodium hypochlorite irrigation within a simulated root canal model

Root canal irrigation is an important adjunct to control microbial infection. The aim of this study was to investigate the effect of 2.5% (wt/vol) sodium hypochlorite (NaOCl) agitation on the removal, killing, and degradation of Enterococcus faecalis biofilm. A total of 45 root canal models were manufactured using 3D printing with each model comprising an 18 mm length simulated root canal of apical size 30 and taper 0.06. E. faecalis biofilms were grown on the apical 3 mm of the models for 10 days. A total of 60 s of 9 ml of 2.5% NaOCl irrigation using syringe and needle was performed, the irrigant was either left stagnant in the canal or agitated using manual (Gutta-percha), sonic, and ultrasonic methods for 30 s. Following irrigation, the residual biofilms were observed using confocal laser scanning, scanning electron, and transmission electron microscopy. The data were analyzed using one-way ANOVA with Dunnett post hoc tests at a level of significance p ≤ .05. Consequence of root canal irrigation indicate that the reduction in the amount of biofilm achieved with the active irrigation groups (manual, sonic, and ultrasonic) was significantly greater when compared with the passive and untreated groups (p < .05). Collectively, finding indicate that passive irrigation exhibited more residual biofilm on the model surface than irrigant agitated by manual or automated (sonic, ultrasonic) methods. Total biofilm degradation and nonviable cells were associated with the ultrasonic group.

A comparison of apical sealing ability between GuttaFlow and AH plus: An in vitro study

Aims:

The present study aimed to compare apical sealing ability between GuttaFlow and AH Plus.

Materials and Method:

Eighty extracted human maxillary anterior teeth with fully formed apex and straight root were collected for this study. The root canals were cleaned and shaped using a standard step back preparation to size 60# master apical file at the established working length and divided into four groups: Group 1, GuttaFlow sealer with gutta-percha; Group 2, AH Plus sealer with gutta-percha; Group 3, positive control group (Teeth were instrumented and left without obturation); Group 4, negative control group (Teeth were totally coated with nail varnish) Dye leakage was carried out. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.

Results:

The GuttaFlow group had a mean leakage of 1.38 mm whereas AH Plus had a mean of 1.425 mm. The standard deviation of GuttaFlow and AH Plus were 0.3861 and 0.3226, respectively. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.

Conclusion:

None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal. GuttaFlow and AH Plus showed no statistically significant difference in microleakage; the better result was shown by GuttaFlow.

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.

Sealing ability of three hydrophilic single-cone obturation systems: An in vitro glucose leakage study

Aim:

The aim of this study is to compare the corono-apical sealing ability of three single-cone obturation systems using a glucose leakage model.

Materials and Methods:

A total of 90 freshly extracted human maxillary single-rooted teeth was selected, and their crowns were cut. The root canal of each sample was instrumented using a rotary crown down technique and then divided into four experimental (n = 20 each) and two control groups (n = 5 each). Samples in the experimental groups were filled as follows: Group 1, cold lateral condensation using gutta-percha/AH Plus; group 2, single-cone C-points/smart-paste bio-sealer; group 3, single-cone bio-ceramic (BC) impregnated gutta-percha/endo-sequence BC sealer; group 4, single-cone Resilon/RealSeal SE after 7 days, the sealing ability of root canal fillings was tested at different time intervals using glucose leakage model. Glucose leakage values were measured using a spectrophotometer and statistically analyzed.

Results:

The four experimental groups presented significantly different glucose leakage values at all test periods (P < 0.05). At the end of the observation period, the cumulative glucose leakage values of groups 2 and 3 were significantly lower than those of groups 1 and 4 (P < 0.05).

Conclusion:

C-points/smart-paste Bio and BC impregnated gutta-percha/endo-sequence BC sealer combinations provided the superior sealing ability over the lateral condensation technique.

Sealing ability of three single-cone obturation systems: An in-vitro glucose leakage study

AIM

The aim of this study is to compare the corono-apical sealing ability of three single-cone obturation systems using a glucose leakage model.

MATERIALS AND METHODS

A total of 90 extracted maxillary single rooted teeth were selected and their crowns were cut. The root canal of each sample was instrumented using a rotary crown down technique and then divided into four experimental (n = 20 each) and two control groups (n = 5 each). Samples in the experimental groups were filled as follows: Group 1, cold lateral condensation using Gutta-percha/AH Plus; Group 2, single-cone Gutta-percha and AH Plus; Group 3, single-cone Gutta-percha/and GuttaFlow2; Group 4, single-cone Resilon/RealSeal SE after 7 days, the sealing ability of root canal fillings was tested at different time intervals using glucose leakage model. Glucose leakage values were measured using a spectrophotometer and statistically analyzed.

RESULTS

The four experimental groups presented significantly different glucose leakage values at all test periods (P < 0.05). At the end of the observation period, the cumulative glucose leakage values of Groups 3 and 4 were significantly lower than those of Groups 1 and 2 (P < 0.05).

CONCLUSION

Gutta-percha/GuttaFlow2 or Resilon/RealSeal SE combinations provided the superior sealing ability over the lateral condensation technique.

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.

Assessment of the wetting behavior of three different root canal sealers on root canal dentin

Aim:

The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination.

Materials and Methods:

Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18). The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA), 3% sodium hypochlorite (NaOCl) and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE), sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA) 200 dynamic contact angle analyzer.

Results:

The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups.

Conclusion:

The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer.

In vitro resistance to fracture of roots obturated with Resilon or gutta-percha

INTRODUCTION

There have been varied results from studies comparing postendodontic fracture resistance between teeth obturated with Resilon or gutta-percha. This study was performed to evaluate the fracture resistance of roots obturated by using Resilon (RealSeal system) or gutta-percha (with AH Plus sealer).

METHODS

Eighty extracted human mandibular single-rooted premolars stored in 10% formalin were used in the study. They were prepared by using a crown-down technique, debrided with NaOCl, ethylenediaminetetraacetic acid, and sterile water and divided into 4 groups. Obturation was performed by using the lateral condensation method. The negative control group consisted of unfilled specimens, and the positive control group consisted of those obturated with flowable, dual-cure composite resin. All root specimens were stored for 2 weeks in 100% humidity to allow complete setting of the sealer. Each specimen was mounted in acrylic in a polyvinyl ring and tested for fracture resistance with the Universal testing machine. The loading fixture of the machine was mounted with its spherical tip aligned with the center of the canal opening of each root. A vertical loading force was applied until it fractured the root. The force values were subjected to statistical analysis including analysis of variance and Fisher least significant difference testing.

RESULTS

Teeth obturated with Resilon were more resistant to fracture than those obturated with gutta-percha. The difference was found to be highly significant (P=.00001).

CONCLUSIONS

Resilon increased the resistance to fracture of single-rooted teeth in vitro.

Potential systematic error in laboratory experiments on microbial leakage through filled root canals: review of published articles

AIM

To systematically evaluate whether published studies on microbial leakage through filled root canals in human teeth embedded in a two-chamber system were properly controlled. Specifically, the control for the assumption that leakage should occur through the root canal rather than other routes was investigated.

METHODOLOGY

A systematic search was conducted using Medline, Biosis, Cochrane, Embase, and Web of Science databases. In addition, the reference lists of review articles pertaining to the topic were searched. No language restriction was applied. Two independent reviewers screened titles and abstracts. All articles deemed appropriate by either reviewer were included in the full-text evaluation. In case of disagreement, a referee arbitrated between the reviewers.

RESULTS

With 93.8% agreement prior to discussion and arbitration, 67 articles were included. On average, the size of the negative control group was 30% (mean) of the n in the experimental groups (minimum=0.0%, maximum=100%, SD=27%). The majority of studies (57 of 67) used inadequate negative controls. The whole root was covered with the sealing material in these specimens, whilst the root tip was left uncovered in the experimental groups. Consequently, leakage between outer root surface and sealing material was not controlled for. The authors of the remaining 10 communications did not state clearly how negative control assessments were performed.

CONCLUSIONS

Experimental investigations should be performed to assess the routes of microbial leakage in two-chamber models.

A comparative evaluation of 3 root canal filling systems

OBJECTIVE

This in vitro study was conducted to evaluate and compare the microbial leakage of a new obturation system: Guttaflow with resin-based Resilon cones and Epiphany sealer, keeping gutta-percha with AH plus sealer as the standard.

STUDY DESIGN

The microbial leakage was tested using Enterococcus faecalis ATCC 29,212 as the bacterial marker in the microbial leakage test. These results were supplemented with scanning electron microscopy (SEM).

RESULTS AND CONCLUSION

The microbial leakage test indicated good sealing abilities for Resilon and Guttaflow, with the latter resisting microbial leakage for a longer period. AH plus with gutta-percha showed poor sealing ability. Results of the scanning electron microscopy correlated with the microbial leakage test. This study indicates that newer obturation systems like Guttaflow and Resilon cones with Epiphany provide better seal against microbial leakage than the standard obturation material, gutta-percha used with AH plus sealer.

[Microleakage of root canal fillings with GuttaFlow and Resilon compared with lateral condensation]

Epiphany/Resilon and GuttaFlow are newly developed methods for obturation of the root canal system. Epiphany/Resilon is a thermoplastic, synthetic polymer-based root canal filling material which enables the bonding to the dentin root canal wall during root canal obturation. GuttaFlow is a cold flowable filling system for the obturation of root canals, combining sealer and gutta-percha in one product. The purpose of this study was to assess the leakage of the Epiphany/Resilon or GuttaFlow root canal filling compared with lateral condensation of gutta-percha. For this study were used 45 human extracted teeth, chemo mechanically prepared, divided into three groups and obturated with gutta-percha/AH Plus, Epiphany/Resilon and GuttaFlow. For dye penetration all teeth were centrifuged for three minutes at 30 g in 2% methylene blue and dissolved in 65% nitric acid for 3 days. The extracted methylene blue was determined with Photometer. Root Canal fillings with Epiphany/Resilon showed less dye penetration than lateral condensation of gutta-percha and GuttaFlow. Epiphany/Resilon is ideally suited as a root canal filling material.