Apical Leakage of Resin Based Root Canal Sealers with a New Computerized Fluid Filtration Meter

Nanoleakage of apical sealing using a calcium silicate-based sealer according to canal drying methods

Objectives

This study investigated the nanoleakage of root canal obturations using calcium silicate-based sealer according to different drying methods.

Materials and Methods

Fifty-two extracted mandibular premolars with a single root canal and straight root were selected for this study. After canal preparation with a nickel-titanium rotary file system, the specimens were randomly divided into 4 groups according to canal drying methods (1: complete drying, 2: blot drying/distilled water, 3: blot drying/NaOCl, 4: aspiration only). The root canals were obturated using a single-cone filling technique with a calcium silicate-based sealer. Nanoleakage was evaluated using a nanoflow device after 24 hours, 1 week, and 1 month. Data were collected twice per second at the nanoscale and measured in nanoliters per second. Data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U-tests (p < 0.05).

Results

The mean flow rate measured after 24 hours showed the highest value among the time periods in all groups. However, the difference in the flow rate between 1 week and 1 month was not significant. The mean flow rate of the complete drying group was the highest at all time points. After 1 month, the mean flow rate in the blot drying group and the aspiration group was not significantly different.

Conclusions

Within the limitations of this study, the canal drying method had a significant effect on leakage and sealing ability in root canal obturations using a calcium silicate-based sealer. Thus, a proper drying procedure is critical in endodontic treatment.

A New Mass Spectroscopy-Based Method for Assessing the Periodontal-Endodontic Interface after Intracanal Placement of Biomaterials In Vitro

Optimizing the interface between biomaterials and dental hard tissues can prevent leakage of bacteria or inflammatory mediators into periapical tissues and thus avoid alveolar bone inflammation. In this study, an analysis system for testing the periodontal-endodontic interface using gas leakage and subsequent mass spectrometry was developed and validated using the roots of 15 single-rooted teeth in four groups: (I) roots without root canal filling, (II) roots with an inserted gutta-percha post without sealer, (III) roots with gutta-percha post and sealer, (IV) roots filled with sealer only, and (V) adhesively covered roots. Helium was used as the test gas, and its leakage rate was found by measuring the rising ion current using mass spectrometry. This system made it possible to differentiate between the leakage rates of tooth specimens with different fillings. Roots without filling showed the highest leakage values (p < 0.05). Specimens with a gutta-percha post without sealer showed statistically significantly higher leakage values than groups with a filling of gutta-percha and sealer or sealer alone (p < 0.05). This study shows that a standardized analysis system can be developed for periodontal-endodontic interfaces to prevent biomaterials and tissue degradation products from affecting the surrounding alveolar bone tissue.

The Preventive Effect of A Magnetic Nanoparticle-Modified Root Canal Sealer on Persistent Apical Periodontitis

Persistent apical periodontitis is a critical challenge for endodontists. Developing root canal filling materials with continuous antibacterial effects and tightly sealed root canals are essential strategies to avoid the failure of root canal therapy and prevent persistent apical periodontitis. We modified the EndoREZ root canal sealer with the antibacterial material dimethylaminododecyl methacrylate (DMADDM) and magnetic nanoparticles (MNPs). The mechanical properties of the modified root canal sealer were tested. The biocompatibility of this sealer was verified in vitro and in vivo. Multispecies biofilms were constructed to assess the antibacterial effects of the modified root canal sealer. We applied magnetic fields and examined the extent of root canal sealer penetration in vitro and in vivo. The results showed that EndoREZ sealer containing 2.5% DMADDM and 1% MNP had biological safety and apical sealing ability. In addition, the modified sealer could increase the sealer penetration range and exert significant antibacterial effects on multispecies biofilms under an external magnetic field. According to the in vivo study, the apices of the root canals with the sealer containing 2.5% DMADDM and 1% MNP showed no significant resorption and exhibited only a slight increase in the periodontal ligament space, with a good inhibitory effect on persistent apical periodontitis.

Farklı irrigasyon tekniklerinin kalsiyum hidroksit uzaklaştırma etkinliğinin Bilgisayarlı Sıvı Filtrasyon methodu kullanılarak mikrosızıntılarının değerlendirilmesi

Aim: To compare the efficiency of sonic irrigation, passive ultrasonic irrigation, and conventional syringe irrigation (CI) in removing pure and injectable calcium hydroxide (CH) from the root canals of mandibular second premolars by measuring the probable microleakage of residual CH particles in root canal obturation using computerized liquid filtration (CLF). Materials and Methods: Eighty instrumented mandibular second premolars were categorized into three experimental groups (n = 20 each) based on the irrigation method used for removing CH and a control group (n = 20) in which CH was not used. Each experimental group was divided into two equal groups (pure and injectable CH). After 1 week, CH was removed from the root canals, and the teeth were obturated. CLF measurements were performed 1 week after obturation. Nonparametric variables between two groups were compared using the Mann-Whitney U test, and the Kruskal-Wallis test was used to compare more than two groups. The significance level was set at p &lt; 0.05. Results: All experimental groups showed higher leakage values than the control group. The highest leakage values were evident in the CI group, and the lowest leakage values were found in the sonic (EDDY) irrigation group. No significant differences were detected among the different forms of CH. Conclusions: None of the analyzed techniques could completely remove CH from root canals, resulting in higher leakage values. Sonic irrigation with EDDY was the best in removing CH from root canals.

A Scanning Electron Microscopic Study on Effect of Blood and Artificial Salivary Contamination on Marginal Adaptation of Mineral Trioxide Aggregate, When Used as a Retrograde Filling Material: An In Vitro Study

Aim and objective

The present study was conducted to evaluate the marginal adaptability of mineral trioxide aggregate (MTA) as a root-end filling material when manipulated using two different IV fluids intended for pediatric usage; in the presence of blood and salivary contamination.

Materials and methods

Sixty single-rooted teeth were selected. Conventional endodontic root canal preparation was performed on all specimens followed by root-end resection and retrograde cavity preparation. The roots were randomly divided into two groups (n = 30). In the specimens of group I, fresh blood was used as a contaminant and in group II artificial saliva was used as a contaminant. In both groups, MTA (e-MTA, Kids-e-Dental®) manipulated using either Ringer's lactate IV fluid (n = 15) or Tetraspan IV fluid (n = 15) was used for root-end filling in blood or artificial saliva-coated retrocavities. Furthermore, these roots were placed in beakers pooled with fresh phlebotomized blood or artificial saliva. After incubating for 48 hours, the roots were divided longitudinally to expose the retrofilled cavities and were then sputter-coated with gold-platinum dust. To assess the marginal adaptation of MTA to radicular dentin "maximum gap width" and "gap perimeter" were measured in images obtained from scanning electron microscopy of root specimens. SPSS 21 was employed for statistical analysis at (p < 0.05). Mann-Whitney U test and ANOVA were used for analyzing the data obtained.

Results

The gap width was more among samples exposed to blood (p < 0.05) than artificial saliva. No significant difference was reported in the gap perimeter when cavities were filled with MTA mixed with either IV fluids (p > 0.05).

Conclusion

Exposure to blood during setting had a negative effect on gap width when retrocavities were filled with MTA using Tetraspan. No effect was seen on the arch perimeter in retrocavities filled with MTA mixed with Ringer's lactate or Tetraspan.

Clinical significance

For avoiding failure, it is critical to select a biocompatible root-end filling material with high sealing ability. Hence, by doing the same, the clinical situation can be simulated.

How to cite this article

Mody A, Arora R, Chauhan P, et al. A Scanning Electron Microscopic Study on Effect of Blood and Artificial Salivary Contamination on Marginal Adaptation of Mineral Trioxide Aggregate, When Used as a Retrograde Filling Material: An In Vitro Study. Int J Clin Pediatr Dent 2021;14(5):674-680.

Sealing ability of three different materials to repair furcation perforations using computerized fluid filtration method

Background. The present study aimed to evaluate the sealing ability of three different calcium silicate-based materials in furcation perforations.

Methods. Seventy-six human mandibular molar teeth were selected. Perforations were created in the center of the pulp chamber floor. The experimental teeth were randomly divided into three groups (n=22). Perforations were repaired with MTA Angelus, Endocem MTA, or EndoSequence BioCeramic Root Repair Material Fast Set Putty (BC-RRM Putty). Microleakage of the different repair materials to be tested was measured by computerized fluid filtration method at 24- and 72-hour intervals.

Results. For each time interval, no statistically significant difference was observed between the groups. For Endocem MTA and BC-RRM Putty groups, the difference between the leakage values measured at both periods was not statistically significant (P > 0.05). However, there was a significant difference for the MTA Angelus group (P < 0.05).

Conclusion. All the calcium silicate-based materials used in the present study showed similar performance in repairing furcation perforations at 24- and 72-hour intervals.

Real-time nanoleakage and the flow characteristics of calcium silicate root canal filling materials

This study aimed to investigate the real-time nanoleakage and flow characteristics of calcium silicate-based (Ca-Si) root canal filling materials. Extracted human teeth (n = 30) were decoronated and standardized in their inner and outer dimensions. After root canal enlargement, the roots were filled with gutta-percha (GP) and AH26 sealer, GP and EndoSeal MTA sealer, or Biodentine. The roots were connected to a Nanoflow device (IB Systems) under hydrostatic pressure (40 cm∙H₂O) and fluid flow was traced through the filled roots. Data were detected at the nanoscale twice per second and automatically recorded in units of nL/s. Leakage was quantified as the mean slope until the curve plateaued over time, and all static flow intervals lasting longer than 1 s were analyzed to identify any increase in flow and duration. Data were statistically analyzed using the Kruskal-Wallis test. The calculated leakage values were 0.0670 ± 0.0516 nL/s for GP/AH26, 0.1397 ± 0.1579 nL/s for GP/EndoSeal MTA, and 0.0358 ± 0.0538 nL/s for Biodentine, with no statistically significant differences among the root filling materials (P > 0.05). An analysis of real-time flow data for 1000 s to identify spot trends and the overall tendency of flow until a plateau was reached revealed a stepwise increase in the roots filled with Ca-Si material, whereas the GP/AH26-filled roots showed a linear increase. Real-time measurements under hydrostatic pressure with the Nanoflow device enabled precise fluid flow tracing through the root canal filling material. In terms of nanoleakage, the tested root canal filling materials showed no significant differences, while the real-time flow patterns of roots filled with Ca-Si material showed different characteristics from those of GP/AH26-filled roots.

Evaluation of the effects of Er:YAG laser, Nd:YAG laser, and two different desensitizers on dentin permeability: in vitro study

The purpose of this in vitro study was to evaluate and compare the efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, PrevDent nano-hydroxyapatite toothpaste plus Repairing Serum Kit (PNH), and NUPRO Sensodyne Prophylaxis Paste with NovaMin (NPP) on dentin permeability reduction. Forty dentin discs obtained from bovine incisors were divided into four study groups: Er:YAG laser-treated (2940 nm; 0.2 W, 80 mJ/pulse, 3 Hz); Nd:YAG laser-treated (1064 nm; 1 W, 10 Hz); PNH-treated; and NPP-treated groups. The quantitative changes in permeability of each dentin disc were measured using a computerized fluid filtration method (CFFM) before and after desensitizer treatments. The data were analyzed using the Wilcoxon, paired-samples t, Kruskal-Wallis, and Mann-Whitney U tests. The dentin surfaces and tubules were also morphologically detected by scanning electron microscopy (SEM). In all groups, dentin permeability was significantly reduced after the desensitizer and laser treatments (p < 0.05). Among the groups, we detected a significant difference in only when comparing the Er:YAG laser- and NPP-treated groups (p = 0.034). SEM analysis revealed physical changes in the dentin surface in all groups. This in vitro study shows that all tested desensitizers and laser treatments reduced dentin permeability. Also, surface changes, such as complete or partial occlusion or shrinkage of dentin tubules, were observed in all groups. Although the laser groups performed best, the PNH protocol can be considered as an alternative therapeutic product. In addition, clinical and laboratory studies should be performed for this product, and their efficacy should be assessed by combined therapy with lasers.

Influence of Post Space Preparation on the Apical Leakage of Calamus, Single-Cone and Cold Lateral Condensation Obturation Techniques: A Computerized Fluid Filtration Study

PURPOSE

Apical microleakage between the root canal and periapical tissues is considered a common cause of endodontic failure. The aim of this study was to evaluate the apical microleakage of various obturation techniques after immediate post space preparations with different drills.

MATERIALS AND METHODS

One hundred twenty human single-rooted teeth were selected for this study. The coronal portions were removed to achieve a uniform length of 15 mm. All root canals were instrumented with ProTaper Next rotary files using crown-down technique. The 120 roots were randomly assigned to 3 experimental groups according to obturation technique (n = 40). The root canals were obturated with lateral condensation in group 1, single-cone technique in group 2, and Calamus 3D obturation system in group 3. Each group was divided into two subgroups (n = 20) according to drill types (Gates Glidden and Peeso drills) leaving 5 mm of apical gutta-percha. The apical microleakage was measured using the computerized fluid filtration meter method. The results were evaluated using Kruskal-Wallis test with Bonferroni Corrected Mann-Whitney U multiple comparison post hoc tests.

RESULTS

There was no statistically significant difference between obturation techniques after post space preparation with Peeso drills (p > 0.05). In Gates Glidden drill groups, single-cone technique demonstrated higher leakage (0.0051 ± 0.0037 μl x min^-1 × cmH₂ O^-1 ) than Calamus techniques (0.0019 ± 0.0012 μl x min^-1 × cmH₂ O^-1 ) (p < 0.017).

CONCLUSIONS

Gates Glidden drills caused the highest apical leakage in teeth obturated with single-cone technique.

Evaluation of Five Different Desensitizers: A Comparative Dentin Permeability and SEM Investigation In Vitro

BACKGROUND/OBJECTIVE

The purpose of this study was to evaluate the efficacy and durability of five different dentin desensitizers (Gluma Desensitizer Powergel, Bifluorid 12, Gluma Self Etch Bond, D/Sense Crystal, Nupro Sensodyne Prophylaxis Paste with Novamin) on tubule occlusion and dentin permeability reduction in vitro.

METHOD

The quantitative changes in permeability of 100 dentin discs were measured after desensitizer treatments and following post-treatments of 6% citric acid challenge for 1 min or immersion in artificial saliva for 24 hours under hydrostatic pressure generated by a computerised fluid filtration meter. Qualitative SEM analyses were also carried out.

RESULTS

Dentin permeability decreased after desensitizer application in all groups. Nevertheless, only the difference between 'Gluma Self Etch Bond' and 'Nupro Sensodyne Prophylaxis Paste with Novamin' groups was significantly different (p<0.05). Dentin permeability increased significantly after post-treatments (p<0.05). There was no statistically difference among the citric acid-subgroups (p>0.05). Of all the artificial saliva-subgroups, only the difference between 'D/Sense Crystal' and 'Bifluorid 12' was significantly different (p<0.05). In SEM analysis, morphological changes were detected on the dentin surface and within the tubules following desensitizer treatments and post-treatments.

CONCLUSION

All the desensitizers significantly reduced dentin permeability by changing the morphology of the dentin surface and/or dentinal tubules. Following post-treatments, there was some reduction in the efficacy of the desensitizers which was represented by the reduction in permeability values. SEM analysis revealed some physical changes in the dentin structure which can partly give an explanation to the reduced efficacy of tested desensitizers.

Microleakage of 4 post-luting cements evaluated by the computerized fluid filtration method

PURPOSE

The aim of this study was to evaluate the microleakage of 4 fiber post-luting systems using the computerized fluid filtration method.

METHODS

60 extracted human mandibular permanent premolar teeth were used for the study. The teeth were instrumented with Hedstroem files up to size 60, post spaces were prepared and then Unicore fiber posts were cemented using 4 luting systems. Group1: Duolink, Group 2: Resinomer, Group 3: Fuji Plus, Group 4: Multilink Sprint, Group 5: Positive Control, and Group 6: Negative Control. The samples were stored in distilled water for 2 weeks and then microleakage was evaluated. Data were analyzed with 1 way-ANOVA and Dunett T3 tests (P&lt;.05). Groups 2 and 3 significantly exhibited higher microleakage values than groups 1 and 4 (P&lt;.05).

RESULTS

Resin cements used with total etch-bonding systems demonstrated lower microleakage values than the other cements.

CONCLUSIONS

Reduction of steps in dentin conditioning of resin luting cements may have a promoting effect on microleakage.

Comparison of apical microleakage of dual-curing resin cements with fluid-filtration and dye extraction techniques

BACKGROUND

Endodontically treated teeth with excessive loss of tooth structure are frequently restored using fiber posts. In this in vitro study, the apical leakage of self- and dual-activated curing modes for dual-curing resins cementing a translucent fiber post was evaluated using computerized fluid filtration meter and dye extraction method.

MATERIAL AND METHODS

One hundred and four extracted human maxillary incisors with single root and canal were used. Experimental samples embedded in a closed system were divided into 4 groups (n=20) according to 2 dual-curing luting systems, with 2 different curing modes (either with self- or light-activation): (1) Panavia F 2.0 with self-cure, (2) Panavia F 2.0 with light-activation, (3) Clearfill SA with self-cure, and (4) Clearfill SA with light activation. Twenty-four teeth served as negative and positive controls. Translucent fiber posts were luted in the roots except in the control groups.

RESULTS

Statistical analysis indicated no significant difference in leakage among groups (p>0.05) with 4.12 × 10(-4) (Panavia self-cure), 4.55 × 10(-4) (Clearfill SA self-cure), 5.17 × 10(-4) (Panavia dual-cure), and 5.59 × 10(-4) (Clearfill SA dual-cure) in fluid-filtration method. Absorbance values for dye-extraction method were 266 nanometer (nm) (Panavia self-cure), 268 nm (Clearfill SA self-cure), 270 nm (Panavia dual-cure), and 271 nm (Clearfill SA dual-cure), in which difference among the groups were not statistically significant (p>0.05). When comparing the leakage, assessment methods results showed no statistically significant difference between the tested evaluation techniques (p>0.05).

CONCLUSIONS

Light- and self-activation curing modes of Panavia F 2.0 and Clearfill SA perform similar to each other in a closed system.

Comparative analysis of three different filling techniques and the effects of experimental internal resorptive cavities on apical microleakage

Objectives:

The aim of this study was to evaluate the sealing abilities of three different gutta-percha techniques in experimentally defective roots (EDR) and non-defective roots (NR).

Materials and Methods:

Sixty canine teeth were divided into six groups of ten; Group 1, NR + cold lateral condensation (CLC); Group 2, EDR + LC; Group 3, NR + BeeFill; Group 4, EDR + BeeFill; Group 5, NR + Thermafil; and Group 6, EDR + Thermafil. Apical leakage was measured using a computerized fluid filtration meter with a laser system.

Results:

Statistical analysis revealed that the CLC demonstrated more microleakage in the EDR than in the NR (P < 0.01). Thermafil demonstrated more microleakage in the NR than in the EDR (P < 0.01). No statistically significant differences were found between the BeeFill groups (P > 0.05).

Conclusions:

The results of this study indicate that internal resorptive cavities can affect the apical sealing properties of different root canal filling techniques, with Thermafil ensuring the lowest apical microleakage.

Fluid flow evaluation of coronal microleakage intraorifice barrier materials in endodontically treated teeth

Objective:

The objective of this study was to compare the coronal microleakage intraorifice barrier materials, called CoroSeal (CS), fissur sealant (FS), flowable composite FC, and policarboksilate cement (PC), by using the computerized fluid filtration method.

Materials and Methods:

Fifty freshly extracted, single-canal human maxillary central teeth were used in this study. The teeth were decoronated to a standardized root length of 15 mm. After preparation and irrigation, all the teeth were obturated with gutta-percha and AH-Plus. In all teeth, the coronal 2 mm of root filling was removed and replaced with one of the intraorifice barriers. According to intraorifice barriers, teeth were divided randomly into 4 experimental groups (n = 10) and 2 control groups (n = 5). Group 1: CS; Group 2: FS; Group 3: FC; and Group 4: PC.

Positive Control Group:

No barrier material was used.

Negative Control Group:

Roots were completely coated with the nail polish, including the orifice. Leakage was evaluated by using a computerized fluid filtration model. Differences in fluid filtration among groups were subjected to statistical analysis using the Kruskal-Wallis Test and multiple comparisons test.

Results:

A value of P < 0.05 was statistically significant. Statistical analysis has indicated that the CS leaked significantly less than other groups (P < 0.05). There was a significant difference between FS and PC (P < 0.05), in contrast there was no significant difference between FS and FC (P > 0.05).

Conclusions:

Using the CS material as an intraorrifice barrier material reduced amount of microleakage as compared with FS, FC, and PC.

Comparative evaluation of the apical sealing ability and adaptation to dentine of three resin-based sealers: An in vitro study

OBJECTIVE

To evaluate the apical sealing ability and adaptation of three resin-based sealers to the dentine.

MATERIALS AND METHODS

A total of 66 recently extracted human maxillary anterior teeth were subjected for the study. The teeth were prepared and obturated with gutta-percha by a lateral condensation using AH Plus, Endorez and Epiphany sealers. Fifteen teeth from each group were used for the apical leakage test and the remaining five teeth from each group were used for examination under the scanning electron microscope. Data were analyzed using one-way ANOVA and the Student Newman-Keuls test.

RESULTS

Epiphany sealer showed better sealing ability and adaptation to dentine.

CONCLUSION

The Epiphany sealer has a better apical sealing ability and adaptation to dentine than the AH Plus and Endorez sealers.

Resin materials for root canal obturation

With the appearance of more in vivo and ex vivo publications, methacrylate based resin sealers are becoming more popular in endodontics. Their ease of use and favorable clinical performance offer an attractive alternative to conventional endodontics. This article reviews the development of resin-based sealers and biocompatibility tests. The many, mostly opposing views are analyzed to put what has been published thus far in perspective. A critical analysis of the facts leads to the consensus that methacrylate based resin sealers are here to stay and offer a suitable alternative to conventional endodontic treatment.

Evaluation of the effect of four self-etching adhesives on dentin permeability

OBJECTIVE

The aim of this study was to evaluate the effect of two two-step and two single-step self-etching adhesives on dentin permeability using a computerized fluid filtration (CFF) test method.

METHODOLOGY

Forty recently extracted sound human molar teeth were sectioned at the mid level of the crown to obtain dentin discs of 1 +/- 0.2 mm. A total of 40 discs were obtained and randomly divided into four groups (n = 10). The permeability of the discs was measured using the CFF test method before and after application of the following self-etching adhesives: Hybrid Bond, G-Bond, AdheSE, and Protect Bond. Fluid movement measurements were made at 2-min intervals for 8 min, and a mean of the values obtained was calculated for each specimen.

RESULTS

The in vitro fluid conductance of dentin discs treated with Hybrid Bond and AdheSE were lower than the dentin discs treated with G-Bond and Protect Bond (p < 0.05).

CONCLUSION

1-Treating dentin discs with self-etching adhesives caused significant reduction of dentin permeability. 2-All self-etching adhesives allowed diffusion of distilled water. However, AdheSE and Hybrid Bond showed the lowest permeability.

Coronal microleakage of two root-end filling materials using a polymicrobial marker

The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly divided into 3 groups of 32 teeth each and positive and negative control groups of 6 teeth and obturated with gutta percha and either Diaket (3M/ESPE, Seefeld, Germany), AH Plus (Dentsply, De Trey, Konstanz, Germany), or Ketac Endo (3M/ESPE). These groups were further divided into 2 subgroups of 16 teeth in which root ends were resected and obturated with either MTA or zinc-free amalgam. The samples have been incorporated in a dual-chamber leakage model with a polymicrobial marker of five facultative anaerobes on the coronal part. Leakage was observing during a period of 90 days. The least leakage was found in a combination of Diaket and MTA (76.9 +/-14.8 days) followed by AH Plus and MTA (66.1 +/- 18.7), Diaket and amalgam (60.0 +/- 23.1), AH Plus and amalgam (56.9 +/- 22.1), and Ketac Endo and MTA (42.1 +/- 17.8), whereas the greatest leakage was observed in the Ketac Endo and amalgam group (40.0 +/- 17.24). Samples filled with MTA showed significantly better sealing than samples filled with amalgam (p < 0.05).

A quantitative evaluation of sealing ability of 4 obturation techniques by using a glucose leakage test

OBJECTIVE

The aim of this study was to evaluate the sealing ability of 4 different obturation techniques by using a glucose leakage test.

STUDY DESIGN

Eighty extracted single-rooted maxillary incisors were selected for the study. The teeth were decoronated and the root canals prepared using ProFile rotary instruments to an apical dimension of size 40 (0.06 taper). The specimens were then randomly divided into 4 experimental groups (n = 15) and filled with gutta-percha and sealer by using either cold lateral compaction, warm vertical compaction, Thermafil, or the E & Q Plus system. Another 10 teeth each served as the positive and negative controls. A glucose leakage model was used for quantitative evaluation of the coronal-to-apical microleakage at 24 hours, 1, 2, 3, 5, 8, and 12 weeks.

RESULTS

No significant difference in the cumulative amount of leakage was found among the 4 groups at 24 hours and 1 week (Kruskal-Wallis test, P > .05). Lateral compaction showed significantly more leakage than the other 3 techniques at longer intervals (Mann-Whitney U test, P < .008). No significant difference was found between vertical compaction, Thermafil, and E & Q Plus at all observation times.

CONCLUSIONS

Warm vertical compaction, Thermafil, and the E & Q Plus system showed a better sealing result than cold lateral compaction of gutta-percha at extended observation periods. The glucose leakage method used in this study was able to provide a nondestructive, quantitative, and long-term evaluation of the sealing ability of root canal fillings.

Sealing properties of two contemporary single-cone obturation systems

AIM

To compare the sealing of root canals filled with two single-cone obturation systems and a warm vertical compaction technique.

METHODOLOGY

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.

RESULTS

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.

CONCLUSIONS

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.

Methodologies for assessment of apical and coronal leakage of endodontic filling materials: a critical review

Apical leakage continues to be a topic of great interest, because in spite of the advances in Endodontics, clinical failures still occur. Most failures are probably attributed to the proliferation of bacteria that remain viable after chemical-mechanical preparation and cause periapical tissue irritation. Coronal leakage has aroused researchers' interest over the last few years, since canals may be re-contaminated after loss of coronal sealing or fracture of the remaining tooth. In this review, the various methodologies used for assessing root canal sealing capacity are critically analyzed, as they are not standardized, which makes it difficult to compare the results obtained when different methodologies are used, even though the same substrate is being assessed.

An In Vitro Evaluation of the Apical Sealing Ability of a New Resin-Based Root Canal Obturation System

The purpose of this study was to assess the apical sealing ability of the new resin-based Epiphany-Resilon root canal filling system, and to compare this with the sealing abilities of different pairings of AH plus, gutta-percha, Epiphany, and Resilon. Seventy extracted human single-rooted teeth were used. All teeth were instrumented using a set of ProTaper rotary instruments. The canal spaces were filled with different combinations of core and sealer using lateral condensation, as follows: group 1, AH Plus + gutta-percha; group 2, AH Plus + Resilon; group 3, Epiphany + Resilon; group 4, Epiphany + gutta-percha. Apical leakage quantity was measured with the computerized fluid filtration meter. Statistical analysis indicated that Epiphany gutta-percha combination had the least amount of microleakage than all the other groups; AH Plus gutta-percha combination proved to have second least amount of microleakage among the groups. AH Plus-Resilon combination demonstrated the greatest amount of microleakage. There were a significant difference between Epiphany gutta-percha and AH Plus-Resilon combinations (p < 0.05). It was found that there were no significant differences between Epiphany-Resilon combination and all the other groups (p > 0.05).

Improving the Performance of EndoREZ Root Canal Sealer With a Dual-cured Two-Step Self-etch Adhesive. II. Apical and Coronal Seal

This study tested the hypothesis that the seal of EndoREZ may be improved with an adhesive-modified technique. Instrumented single-rooted teeth were filled with: (a) Warm vertical compaction with AH Plus (control); (b). EndoREZ with master cones and passive application of accessory cones; (c) Application of Clearfil Liner Bond 2V before EndoREZ and gutta-percha condensation. Leakage was assessed by fluid filtration at 10 psi before root resection and after 3 to 12 mm apical resections. Statistical analyses revealed significant differences in filling technique and resection lengths. EndoREZ exhibited significantly higher overall leakage, while no difference was found between AH Plus and the adhesive-modified EndoRez technique. Apical resection of EndoREZ to 12 mm exhibited more leakage than all other interactions, but was not significantly different from the same material resected to 9 mm. Although EndoREZ exhibited an acceptable apical seal, its coronal seal may be improved with the use of a dual-cured self-etch adhesive.

Bacterial penetration after obturation with four different root canal sealers

The aim of this study was to compare bacterial penetration after obturation with lateral compaction technique using four different root canal sealers. This study was performed on 100 teeth including negative control (n = 10), positive control (n = 10), and experimental groups (n = 80). 80 teeth were randomly divided into five groups of 20 teeth each and obturated with AH 26 (A), AH Plus (AP), Sealapex (S), Ketac-Endo (K) root canal sealers. Evaluation was carried out for 60 days. After 30 days of comparing the bacterial penetration values, total penetration was observed in 85% of the Group AP, and group K, 80% of the group S, and 75% of the group A. According to the results of chi(2) test, there was no statistically significant difference observed between any groups (p > 0.05). After 60 days of comparing the bacterial penetration values, total penetration was observed in 100% of the group AP, group K, and group S and 95% of the group A. It may be concluded that under the conditions of this study, there was no difference in the bacterial penetration of the four root canal sealers tested at 30 and 60 days.