An evaluation of apical leakage of a glass ionomer root canal sealer

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 < 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.

Regenerating a monoblock to obturate root canalsvia a mineralising strategy

To develop a novel strategy for sealing and obturating dental root canals by tooth-like tissue regeneration, premolars with mature root apices were freshly collected, and root canals were prepared by following the clinical protocols in vitro. The teeth were immersed in supersaturated calcium and phosphate solution containing gallic acid and fluoride. At certain intervals, the dental roots were taken out, and their mineral precipitates were characterised by scanning electron microscopy, energy-dispersive spectroscopy mapping, X-ray diffraction and transmission electron microscopy. The cytocompatibility of the mineralizing products were evaluated with rabbit bone-marrow-derived mesenchymal stem cells in vitro. Results showed that the precipitates were mainly composed of fluoridated hydroxyapatite with ahexagonal prism morphology. Fluoridated hydroxyapatite initially nucleated and grew from the root canal dentine surface to the root canal centre. The fluoridated hydroxyapatite precipitate and root canal dentine intergraded together such that the interface became hardly distinguishable. The fluoridated hydroxyapatite precipitate grew into and obturated the dentinal tubules. In the root canal, the regenerated fluoridated hydroxyapatite densely packed and bundled together with a c-axis extension. After 7 days of mineralisation, the root canal was completely obturated, and the apical foramen was sealed. The mineralizing products had good biocompatibility with the cells, and the cells grew well on the mineralized surface. Biomimetic mineralisation strategy provides a novel means to regenerate tooth-like tissue to seal the root canal system permanently other than by passive synthetic material filling.

Clinical applications of glass ionomers in endodontics: a review

Glass ionomer cements (GICs) are biocompatible and have capacities to release fluoride and to bond to dentine, and thus are appropriate for use in endodontics. This paper reviews the composition and properties of different GICs, including their biocompatibility and antibacterial activity, their applications as intraorifice barriers and root canal sealers, and their use in the repair of root perforations, root-end fillings and temporary coronal restorations.

An in vitro study to determine the sealing ability of sealers with and without smear layer removal

AIMS/OBJECTIVES

The objective of this in vitro study is to compare the sealing ability of Ketac-Endo and Acroseal.

MATERIALS AND METHODS

Seventy teeth were selected and sectioned at the cementoenamel junction. The teeth were cleaned and shaped, and they were divided into five different groups. Group1: 20 teeth in which the smear layer was left intact using sodium hypochlorite. Group 2: 20 teeth in which the smear layer was removed using 17% EDTA. Group 3: 20 teeth in which the smear layer was removed using 17% EGTA. These groups (1, 2, and 3) were further subdivided into two subgroups (a and b) by obturation utilizing lateral condensation with Gutta-percha and Acroseal (subgroup "a") or Ketac-Endo (subgroup "b"). The subgroups contained 10 teeth each. Group 4: 5 teeth that were instrumented but not obturated. Group 5:5 teeth that were neither instrumented nor obturated. The specimens were immersed in methylene blue dye, and microleakage was assessed using a stereomicroscope.

RESULTS

The data was analyzed using one way analysis of variance and student's t-test.

CONCLUSION

17% EGTA is a better and potent alternative to 17% EDTA for smear layer removal. Acroseal sealer has less microleakage as compared with Ketac-Endo. Sealing ability of Acroseal sealer is better when it is used in conjunction with 17% EGTA.

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

In this in vitro study, the apical leakage of three root-canal sealers: AH Plus, Diaket, and EndoREZ was evaluated using a new computerized fluid filtration meter. Forty-five extracted human premolar teeth with single root and canal were used. The coronal part of each tooth was removed and the root canals were prepared using GT Rotary files and crown-down technique. The roots were randomly divided into three groups of 15 samples, filled with one of the test materials and gutta-percha cones by the cold lateral condensation technique and were stored at 37 degrees C and 100% humidity for 7 days. One-week later, apical parts of roots of 10 +/- 0.05 mm were attached to computerized fluid filtration meter. Apical leakage quantity was determined as microl/cmH(2)O/min(-1). Statistical analysis indicated that root fillings with Diaket in combination with cold lateral condensation technique showed lower apical leakage than the others (p < 0.05). In addition, this new computerized fluid filtration meter allowed quantitative measurement of leakage easily. As it is a newly developed device to measure apical leakage of endodontic sealers, the reliability of it needed to be tested.

The use of glass ionomer cements in both conventional and surgical endodontics

The capacity to bond to dental tissues, especially to dentine, their long-term fluoride release and their biocompatibility make glass ionomer cements (GICs) advantageous for use in endodontics, as well as in restorative dentistry. This review provides information on the basic properties of GICs, such as adhesion, antimicrobial effects and biocompatibility, particularly as they relate to use in endodontics. Indications for the use of GICs in endodontics are orthograde root canal sealing, root-end filling, repair of perforations and root resorption defects, treatment of vertical fractures and maintenance of the coronal seal. The paper includes a review on each of these indications. It is concluded that in spite of the critical handling characteristics and the inconclusive findings regarding sealing ability and antimicrobial activity, there is substantial evidence to confirm their satisfactory clinical performance. Both soft tissue and bone compatibility make them suitable for use during endodontic surgery.

A comparative study of apical leakage of Apexit, Ketac-Endo, and Diaket root canal sealers

The purpose of this study was to compare the apical leakage of Ketac-Endo, Apexit, and Diaket. Fifty freshly extracted human maxillary anterior teeth were used. The anatomical crowns were removed at the amelocemental junction, and step-back preparation of the roots canals was performed with K-type files to size 40 using 2 ml of 5.25% NaOCl irrigant after each file change. The roots were randomly divided into five groups of 10 roots each: three experimental and two control groups. The experimental groups were as follows: group 1, Apexit; group 2, Ketac-Endo; and group 3, Diaket. Root canals were filled with one of the sealers and gutta-percha using lateral condensation. After the specimens were stored in 100% humidity at 37 degrees C for 2 wk, the roots were covered with two layers of nail polish and immersed in 2% methylene blue for 7 days. Each tooth was split into two sections, and dye penetration was evaluated independently by three examiners using a stereomicroscope at x20 magnification. Mann-Whitney U analysis showed that there was no significant difference between Apexit and Diaket (p > 0.05). However, there was significantly more leakage with Ketac-Endo (p < 0.05).

Evaluation of apical seal in straight canals after obturation using the Lightspeed sectional method

This study evaluated the sectional gutta-percha obturation technique advocated by Lightspeed Technology, Inc. Single relatively straight-canaled teeth were prepared with rotary instruments and divided into three groups. Groups A and B served as controls and were obturated using laterally condensed gutta-percha and either Roth's 801 or Ketac-Endo sealer. Group C was obturated using the Lightspeed technique that included placement of a 5-mm apical section of gutta-percha, followed by backfill with Ketac-Endo sealer and a single gutta-percha cone. All teeth were suspended in India ink for 14 days then cleared. Four additional teeth, which were obturated as in group C then sectioned, revealed a tightly adapted apical section of gutta-percha with a very thin layer of sealer. However, voids were noted in the middle and coronal areas. There was no significant difference in apical microleakage among the three groups. The sectional method was significantly faster than lateral condensation and seems to offer promise as an effective obturation method.

Evaluation of the apical seal of root canal fillings with different methods

The purpose of the study was to compare dye penetration methods conducted passively, under negative pressure, or under high pressure conditions. Ninety human maxillary incisors were instrumented and obturated with either the lateral condensation or single cone technique. India ink was used as a dye for passive and negative pressure (60 Torr) penetration methods. For dye penetration under high pressure conditions (200 MPa), a colored epoxy resin was used. Apical leakage was linearly measured evaluating both the root surface that showed the highest degree of penetration and all four surfaces of each root. The results revealed no significant difference between passive and negative pressure penetration methods. The amount of apical leakage obtained using dye penetration under high pressure conditions was significantly lower. Lateral condensation and single cone techniques yielded similar sealing abilities. It is concluded that there is no need to use negative pressure for evaluating the sealing ability of root canal fillings in vitro.

An in vitro study of apical and coronal microleakage of laterally condensed gutta percha with Ketac-Endo and AH-26

The purpose of this in vitro study was to compare both apical and coronal dye penetration when Ketac-Endo and AH-26 sealers were used with laterally condensed gutta percha. Crowns were removed from 28 teeth and the root canals were biomechanically prepared. The teeth were divided into two groups of 12-teeth each and a control group of 4 teeth. Root canals in the two experimental groups were filled with laterally condensed gutta percha and either Ketac-Endo or AH-26 sealer. The Ketac-Endo group had the coronal 3 mm of gutta percha and sealer removed and the resultant cavity was filled with Ketac-Endo alone. After the sealers had set, the root surfaces were coated with nail varnish except at the apex and at the coronal end. Positive controls had no root fillings and were coated with nail varnish in the same manner while the negative controls were sealed apically and coronally with Cavit prior to sealing the entire external root surface with nail varnish. Specimens were placed in 2% methylene blue dye in a vacuum of 660 mm of mercury for five minutes and then left immersed for a further two days. The roots were vertically sectioned to determine the following mean levels of dye penetration: Ketac-Endo, 1.08 mm apically and 6.29 mm coronally; AH-26, 0.75 mm apically and 6.67 mm coronally. Positive controls had total leakage and negative controls had no leakage. This study demonstrated that the apical and coronal seals obtained with Ketac-Endo and AH-26 were not significantly different although the apical seal obtained with each material was significantly better than the corresponding coronal seal.

Apical leakage in canals filled with glass ionomer sealer and gutta-percha after dentin conditioning

This study assessed in vitro apical leakage in root canals filled with gutta-percha and Ketac-Endo using different dentin conditioning and filling techniques. The root canals of 63 single-rooted teeth were instrumented and randomly divided into the following four groups: group A--canals were irrigated with 25% tannic acid and filled with Ketac-Endo and a standardized gutta-percha cone; group B--canals were irrigated with 1% NaOCl and filled as in group A; group C--canals were irrigated with 25% tannic acid and filled with Ketac-Endo and a chloroform-softened gutta-percha cone adapted to the canal walls; group D--canals were irrigated with 1% NaOCl and filled with Grossman's sealer and laterally condensed gutta-percha. After storage for 72 hours at 37 degrees C and 100% humidity, the gutta-percha was removed to a level 4 mm short of the working length, using a Peeso reamer. Teeth were immersed in India ink for 48 hours and cleared, and the coronal extent of dye penetration examined under a binocular dissecting microscope at x 15 magnification. The mean value of leakage for group A was 0.86 mm, for group B 2.23 mm, for group C 2.34 mm, and for group D 0.56 mm. Tukey's multiple comparison test disclosed significant differences (P < 0.05) between group A and groups B and C, and between group D and groups B and C. Differences between groups A and D, as well as between groups B and C, were not significant.

Disintegration of endodontic cements in water

The disintegration of three endodontic cements in water was determined quantitatively and qualitatively. The materials studied were Ketac-Endo (KE), Tubli Seal (TS), and AH26 (AH). Specimens were immersed in water for 48 h (GI), 7 (GII) and 45 days (GIII). The solid residue was then determined. For the qualitative analysis three groups of tubes were filled with the materials and stored in water for the same periods. The exposed surface was photographed. Results expressed as percentage of original mass in the quantitative analysis for loss of mass due to dissolution were: GI = KE 2.39 (0.70); TS 3.56 (0.37); AH 4.94 (2.83); GII = KE 2.84 (0.30); TS 2.50 (0.50); AH 0.66 (0.26); GIII = KE 1.60 (0.84); TS 1.03 (0.42); AH 1.22 (0.54). Tukey's least significant difference (0.05) was 2.94. In the qualitative experiment KE disintegration was far more evident than that suffered by other materials. The quantitative results had no correlation with the qualitative observations probably due to the difference in the moment when the materials were immersed.

Evaluation of glass ionomer as an endodontic sealant: an in vitro study

This study investigated the sealing ability of glass ionomer as a root canal sealer with and without lateral condensation of gutta percha cones. Ten gutta percha cones were embedded in Grossman's sealer and 10 in glass ionomer sealer. The sealers were mechanically separated from the gutta percha. The cone surfaces were examined using scanning electron microscopy (SEM). SEM revealed a characteristic etch pattern on the glass ionomer group and a hybrid layer on the cone surfaces of the Grossman's group. Additionally, 40 maxillary incisors were divided into four treatment groups: 1) glass ionomer sealer with lateral condensation, 2) glass ionomer sealer with only one master cone, 3) Grossman's sealer with condensation, and 4) Grossman's sealer with only one master cone. The average values for leakage (mm) in groups 1 through 4 were 0.81 +/- 0.75, 4.30 +/- 1.82, 0.67 +/- 0.80, and 1.10 +/- 1.68, respectively. Statistical analysis showed that group 2 leaked more than the other three groups.

Influence of the removal of coronal gutta-percha on the seal of root canal obturations

The purpose of this study was to compare the quality of the coronal seal of lateral and vertical condensations after removal of the coronal gutta-percha with two different techniques. One hundred single-rooted human teeth with one root canal were used. After cleaning and shaping, the teeth were divided into 4 equal groups. In groups 1, 3 and 2, 4 vertical and lateral condensations were performed respectively. Then, the coronal portion of gutta-percha was removed with heat-carriers alone for groups 1 and 2 and with heat-carriers and compaction for groups 3 and 4. Apical microleakage was determined using pressurized fluid filtration measured at different time intervals up to 24 wk. The results showed that the alternation of heat-carriers and compaction enhances the quality of the coronal seal. The obturation with the vertical condensation technique resulted in a better seal independently of the gutta-percha removal technique.

An in vitro evaluation of coronal microleakage in obturated root canals without coronal restorations

A study was conducted to evaluate coronal microleakage of Super EBA and Ketac-Endo when used as sealers with single-cone gutta-percha (GP) root canal obturation. The root canals of 24 extracted human teeth were instrumented with flared preparations to a minimum #40 master apical file size. Ten teeth were obturated with a single GP cone and Super EBA as the sealer and ten teeth were obturated with a single GP cone and Ketac-Endo as the sealer. Four teeth were used as controls. Salivary bacterial microleakage studies were conducted to determine whether these sealers could prevent coronal microleakage through the root canal in the absence of a coronal tooth restoration. There was no bacterial penetration through the apical foramen for either sealer tested during the 60-day test period.

An in vitro evaluation of microleakage of a new root canal sealer

An in vitro dye leakage study was performed to compare the apical microleakage of Ketac-Endo root canal sealer with that of Roth's 801E and AH26 sealers. Sixty-four single-rooted human teeth were instrumented and randomly divided into four groups. Three groups were obturated with laterally condensed gutta-percha and either Roth's 801E, AH26, or Ketac-Endo as the sealer. A fourth group was obturated using a single master cone and the Ketac-Endo sealer. The teeth were suspended in 1% methylene blue dye for 6 days. The teeth were then longitudinally sectioned and evaluated for linear apical dye penetration. In general, Ketac-Endo root canal sealer showed greater dye penetration than Roth's 801E and AH26. There was no statistical difference in leakage between the laterally condensed Ketac-Endo group and the single-cone-obturated Ketac-Endo group.