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

Stereomicroscopic evaluation of sealing ability of four different root canal sealers: an in-vitro study

AIM

To compare and evaluate the sealing ability of four different commercially available sealers to provide seal against the dye penetration test using a stereomicroscope-an in-vitro study.

MATERIAL/METHOD

80 extracted single rooted mandibular premolar with single canal were used in this study. The samples were divided in 4 groups (20 in each) based on sealer. Group I (Diaproseal), Group II (apexit Plus), Group III (MTA Fillapex) and Group IV (Bio-C). The samples were analyzed using a stereomicroscope and data analysis was done with one-way Anova And post hoc Tukey's test.

RESULT

The mean dye penetration score was 1.2400 ± 0.778 mm for Group I. 2.6000 ± 0.897 mm for Group II, 4.2000 ± 0.923 mm for Group III and 4.225 ± 2.055 mm for Group IV. One-way Anova analysis shows that intergroup comparison was statistically significant between the four groups. The post hoc Tukey's test reveals that the difference was statistically non-significant between group III and group IV.

CONCLUSION

It was concluded that between the four groups the Group I (Diaproseal) showed the least dye penetration followed by Group II (Apexit Pus), Group III (MTA Fillapex) and then Group IV (Bio-C), where there was no significant difference between the Group III (MTA Fillapex) and Group IV (Bio-C).

Endodontic retreatment practice trends among dental surgeons: A survey-based research

Aim

Root canal treatment procedures are considered "the bread and butter" for routine clinical practice. Although retreatments have been primarily performed by endodontists (ENs), many senior practitioners and dentists who are root canal enthusiasts do opt for undertaking endodontic retreatment procedures. This survey helps us understand the practice trends and attitude of dentists undertaking endodontic retreatment procedures in and around Mumbai city.

Materials and Methods

Questionnaires pertaining to endodontic retreatment were randomly distributed (hard copy/soft copy) to 1000 practicing dentists in and around Mumbai city. The questionnaire survey was divided into Part A: involving basic details such as name, demographic information, and clinical experience of the dentist and Part B: a set of questions based on assessing the trends, techniques, materials, and opinions of dentists regarding endodontic retreatment. Only those dentists who treated endodontic retreatment patients were asked to fill the Part B form. A response rate of 60.2% was achieved.

Results

Out of total 602 participants, 49% of dentists (295) reported to undertake endodontic retreatment cases. Among the 295 respondents, 46.11% were Endodontists (ENs) while 53.8% were BDS or MDS of other specialties (ODs). Most dentists preferred multi-visit retreatment and prescribed antibiotics only in specific cases. Radiovisiography was the most preferred imaging aid. Calcium hydroxide and 3% sodium hypochlorite were favored choices for intracanal medicament and irrigant, respectively. Cold lateral compaction obturation technique was most common. Advanced equipment such as microscopes, loupes, ultrasonics, retreatment files, and thermoplastic obturations were more prevalent among ENs as compared to ODs.

Conclusion

This study found some differences in endodontic retreatment practice trends among ENs and other dentists. But overall, most clinicians followed the international norms and are updated in recent advances in materials and techniques used in endodontic retreatment.

Evaluation of apical leakage after immediate and delayed postspace preparation using different root canal sealers: An in vitro study

Background

Endodontically treated teeth with extensive loss of tooth structure lacks sufficient support for a permanent restoration. While restoring them with post and core it is important not to disrupt the apical seal.

Aim

Evaluation of apical leakage after immediate and delayed postspace preparation using two root canal sealers.

Materials and Methods

Sixty single-rooted teeth were decoronated and roots were biomechanically prepared and obturated with gutta-percha and 2 sealers: AH Plus (Group A, n = 30) and Sure-Seal root canal sealer (Group B, n = 30). Groups A and B were subdivided into A1, A2 and B1, B2. Postspace was prepared immediately for A1 and B1. For A2 and B2 post space was prepared after storage in physiologic saline for 1 week. The samples were kept in Rhodamine B dye for 72 h and then sectioned longitudinally to observe dye penetration along the root canal wall under Stereomicroscope. The dye penetration was measured linearly and the values were subjected for statistical analysis using one-way analysis of variance and t-test.

Results

Statistically significant difference between Group A (1.00 mm) and B (2.71 mm) was observed (P < 0.001). However, the subgroups for immediate and delayed post space preparation did not show statistically significant difference (A1 = 0.947; A2 = 1.043; B1 = 2.306 and B2 = 3.120, P < 0.001).

Conclusion

AH plus sealer showed lesser leakage compared to Sure-Seal Root canal sealer. The difference in leakage values was not statistically significant in delayed and immediate post space preparation groups, Time of postspace preparation has no influence on apical leakage.

Apical Sealing Ability of Calcite-Synthesized Hydroxyapatite as a Filler of Epoxy Resin-Based Root Canal Sealer

BACKGROUND

The success of root canal treatment is influenced by hermetic root canal obturation. This study was conducted to analyze the apical sealing ability after the addition of calcite-synthesized hydroxyapatite (HA) as an epoxy resin sealer filler.

METHODS

Calcite-synthesized HA powder was prepared using the microwave hydrothermal process. HA resin sealer powder and epoxy resin paste (3:1) were mixed, and concentrations of 10%, 20%, 30%, 40%, and 50% were prepared. A sample of thirty maxillary incisors were prepared in the root canal and then, the crown was cut to leave 13 mm of the root and a working length of 12 mm. The root canal was prepared using the crown-down technique and irrigated using 2.5% sodium hypochlorite and 17% ethylenediaminetetraacetic acid alternately. The samples were divided into six groups, with each group consisting of five roots. Group I was obturated with gutta percha using an epoxy resin sealer without HA (HA-0%) as a control group. In each of the Groups II, III, IV, V, and VI, 10% HA resin sealer, 20% HA, 30% HA, 40% HA, and 50% HA were used. All the samples were incubated in a 10-ml simulated body fluid solution at 37°C for 4 weeks. Apical closure density measurement was done using a scanning electron microscope, and the results were analyzed using the Kruskal-Wallis and Mann-Whitney U-tests.

RESULTS

A significant increase in the apical sealing ability was observed in the HA-20% sealer group and the HA-30% and HA-40% groups compared to that in the control group. However, the HA-50% sealer group showed a decrease in the apical sealing ability, whereas the HA-10% sealer group showed no difference. The HA-30% had the highest sealing ability than other concentrations.

CONCLUSION

The addition of calcite-synthesized HA as a filler at concentrations of 20%, 30%, and 40% increased the apical sealing ability of the epoxy resin sealer.

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

BACKGROUND

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

An in vitro comparison of three delivery techniques for obturation of root canals in primary molars

AIM

This in vitro study evaluated the efficacy of three different obturation techniques with regards to quality of two filling pastes-Ca(OH)₂/iodoform syringe paste and zinc oxide eugenol paste in primary molars.

METHODS

Root canals of 45 extracted primary molars were prepared and randomly divided into three groups of 15 teeth each. Group A-canals were filled with Ca(OH)₂/iodoform syringe paste, Group B-zinc oxide eugenol paste with handheld lentulo spiral and Group C-zinc oxide eugenol paste with rotary lentulo spiral. The quality of filled root canals was evaluated with conventional radiography in antero-posterior and lateral dimensions.

RESULTS

There were significant differences between all groups in the presence of voids (p = 0.03) and length of filling (p = 0.002). Half of the sampled teeth in handheld lentulo spiral group had voids in the filled canals, while 80% of the teeth filled with Ca(OH)₂/iodoform syringe resulted in overfilling of the paste.

CONCLUSIONS

All three delivery methods for the obturation of primary molars' root canals showed inherent limitations in terms of voids and quality of filling. Voids are inevitable and were present in all the techniques. Overfilling was more frequently seen with the syringe method, while the lentulo spiral technique, both handheld and rotary, showed a better quality of filling.

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.

Impact of root canal preparation size and taper on coronal-apical micro-leakage using glucose penetration method

OBJECTIVES

The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration.

MATERIAL AND METHODS

For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force technique, canals in group 1 were prepared apically to size 25 and coronally to size 2 Peesoreamer. Group 2 were instrumented apically and coronally to size 40 and size 6 Peesoreamer, respectively. Rotary instrumentation was accomplished in group 1; using size 25 and .04 tapered and in group 2, size 35 and .06 tapered Flex Master files. Canals were then obturated by lateral compaction of cold gutta-percha. Glucose penetration through root canal fillings was measured at 1, 8, 15, 22 and 30 days. Data were recorded as mmol/L and statistically analyzed with Mann-Whitney U test (P value=. 05).

RESULTS

In comparison to group 1, group 2 showed significant glucose leakage during the experimental period (P value < .0001). Also, in each experimental group, the amount of micro-leakage was significantly increased at the end of the study.

CONCLUSIONS

Under the condition of this study, the amounts of micro-leakage through root canal fillings are directly related to the size and taper of root canal preparation and reducing the preparation size may lead to less micro-leakage. Key words:Dental leakage, root canal preparation, endodontics.

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.

Lack of correlation between microbial penetration method and electro chemical technique for assessment of leakage through the root canal fillings

Aims:

The purpose of this study was to compare microbial penetration method and electrochemical technique for evaluation of the apical seal.

Materials and Methods:

A total of 28 teeth were prepared using the step-back technique to ISO size 40 master apical files. The specimens were randomly divided into an experimental group, two positive and two negative controls. Root canals in the experimental and negative control group were filled with gutta-percha (GP) and sealer, using lateral condensation technique. In the positive control group, canals were filled with GP without any sealer. The external surface of each tooth was coated with two layers of the nail varnish, except for the access opening and the apical foramen. In the negative control group, the teeth were completely covered with nail varnish. The apical seal was recorded with two methods, each successively used on the same teeth: An electrochemical method and a bacterial penetration method.

Statistical Analysis Used:

The correlation of the electro chemical readings with the results obtained from bacterial micro leakage test was evaluated by Pearson's correlation coefficient.

Results:

Correlation coefficient of the measurements obtained from the two evaluation methods, was 0.23 (r = 0.23), so the correlation was not statistically significant (P = 0.275).

Conclusions:

This study shows that several studies by different methods are necessary before evaluation of the marginal leakage.

Chemical treatment of the intra-canal dentin surface: a new approach to modify dentin hydrophobicity

Objective:

This study evaluated the hydrophobicity of dentin surfaces that were modified through chemical silanization with octadecyltrichlorosilane (OTS).

Material and Methods:

An in vitro experimental study was performed using 40 human permanent incisors that were divided into the following two groups: non-silanized and silanized. The specimens were pretreated and chemically modified with OTS. After the chemical modification, the dentin hydrophobicity was examined using a water contact angle measurement (WCA). The effectiveness of the modification of hydrophobicity was verified by the fluid permeability test (FPT).

Results and Conclusions:

Statistically significant differences were found in the values of WCA and FPT between the two groups. After silanization, the hydrophobic intraradicular dentin surface exhibited in vitro properties that limit fluid penetration into the sealed root canal. This chemical treatment is a new approach for improving the sealing of the root canal system.

Effects of three different irrigating solutions and KTP laser irradiation on apical leakage: an electrochemical study

OBJECTIVE

The purpose of this study was to evaluate the effect of three different irrigating solutions (17% EDTA, 10% citric acid and 2.5% NaOCl) and KTP laser irradiation on apical leakage using an electrochemical method.

MATERIALS AND METHODS

Sixty extracted single-rooted human teeth with mature apices were instrumented up to a size 35 K-file. After using each file and before proceeding to the next, canals were irrigated with 2 ml of 2.5% NaOCl. All teeth were then randomly divided into four groups. In group 1, the root canals were irrigated with a final flush of 17% EDTA. In group 2, the root canals were irrigated with a final flush of 10% citric acid. In group 3, the root canals were irradiated with KTP laser at 1 W, 4.45 J/cm(2). In group 4, the root canals were irrigated with a final flush of 2.5% NaOCl. The root canals were then filled using the cold lateral condensation method. Apical leakage was evaluated using an electrochemical method over a period of 10 days. Data were analysed using Tukey HSD and Friedmann tests with p = 0.05 as the level for statistical significance.

RESULTS

The 17% EDTA and 10% citric acid groups had statistically less apical leakage than the 2.5% NaOCl group at days 7, 8, 9 and 10 (p < 0.05); however, no significant differences were found between the tested groups at the other time intervals (p > 0.05). No significant difference was found between the KTP laser group and other groups tested at all time intervals (p > 0.05).

CONCLUSION

All groups were unable to eliminate apical leakage. However, final irrigation with 17% EDTA and 10% citric acid following root canal preparation reduced postobturation apical leakage compared with 2.5% NaOCl irrigation. When KTP laser and the other three irrigants were compared, no significant difference was found.

In vitro comparative study of the microbial leakage of one-step, thermafil and lateral condensation techniques

AIM

To compare the apical seal of lateral condensation technique, thermafil and one-step by using this model.

MATERIALS AND METHODS

A two-chamber bacterial microleakage model using E. faecalis as microbial marker was used for evaluation of the leakage. Bacterial penetration was monitored over a 60-day period. Leakage was recorded when turbidity was observed in the lower chamber.

RESULTS

After comparing the bacterial penetration values, total penetration was observed 45% in lateral condensation technique, 80% in thermafil and 75% in one-step. There was no significant difference between groups after 60 days; however, the microleakage in lateral condensation group was seen later than one-step and thermafil.

CONCLUSION

Thermafil and one-step obturator can be advocated as effective obturation techniques for achieving predictable success in endodontic therapy.

CLINICAL SIGNIFICANCE

Thermafil and one-step obturator are suitable devices for obturation.

Assessment of the apical seal of root canals using different filling techniques

The aim of this study was to investigate the apical leakage of roots filled by three different gutta-percha techniques: lateral condensation, Tagger's hybrid and E&Q Master. Forty-two extracted single-rooted teeth were used. The coronal part of each tooth was removed and the root received biomechanical preparation using a 60-K file. The roots were randomly divided into three groups according to the technique of filling the root canal: Group I, lateral condensation; Group II, Tagger's hybrid; Group III, E&Q Master. The roots were submitted to dye leakage test with Rhodamine B for 7 days, using vacuum during the initial 30 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. Statistical analysis indicated that lateral condensation and E&Q Master techniques showed lower leakage than Tagger's technique (P = 0.0016). However, statistically no difference was found between lateral condensation and E&Q Master system techniques.