Coronal Seal Research Articles

Effectiveness of different irrigation solutions on triple antibiotic paste removal from simulated immature root canal.

To evaluate the effectiveness of different irrigation solutions and ultrasonic activation of irrigation solutions on removal of triple antibiotic paste (TAP) from root canals of the simulated immature teeth. Fifty single-rooted teeth were used. TAP was placed into each root canal, and specimens were stored in distilled water for 4 weeks at 37°C. After 4 weeks, the temporary coronal seal was removed and the samples were randomly divided into five groups as follows: (i) saline; (ii) ultrasonic activation of saline; (iii) NaOCl; (iv) ultrasonic activation of NaOCl; (v) chlorhexidine digluconate (CHX). The amount of remaining TAP on the canal walls was measured under stereomicroscope with 30× magnification. The data were analyzed using a one-way ANOVA and post-hoc Tukey test at a significance level of 0.05. There were statistically differences among CHX and ultrasonic activation of NaOCl and other groups (p < 0.05). There were no significant differences among the ultrasonic activation of saline, NaOCl, and saline groups (p > 0.05). Irrigation solutions and ultrasonic activation of the irrigation solutions could not completely remove the triple antibiotic paste from simulated immature root canals. Ultrasonic activation of the NaOCl gave the best and CHX was the worst results.

Restoration of the root canal treated tooth.

When considering endodontically treated teeth, the quality of the restoration is important from the outset. It sheds light into possible causes of pulp necrosis or failure of endodontic treatment and influences the outcome of future endodontic treatment. A tooth undergoing endodontic treatment requires an effective coronal seal during and following completion of endodontic treatment. This paper discusses, using the available literature, the maintenance of optimal coronal seal and coronal integrity during and after root canal treatment.

Effectiveness of different irrigation protocols on calcium hydroxide removal from simulated immature teeth after apexification

Aim: To evaluate the effectiveness of different irrigation solutions and ultrasonic activation of the irrigation solutions on the removal of calcium hydroxide (Ca(OH)2) from the simulated immature root canals after apexification.Materials and methods: One-hundred and one single-rooted teeth were used. The root canals were shaped with ProTaper rotary files up to F5. Simulation of roots with immature apices was carried out using size 4 Unicore drills. An injectable Ca(OH)2 was injected into each root canal, and packed to the working length. Then, cotton pellets were placed over canal orifices, and apical and coronal parts of the roots were sealed with resin-modified glass ionomer cement, and light cured. Specimens were stored in distilled water for 3 months at 37°C. After 3 months, the temporary coronal seal was removed and the samples were randomly divided into: (a) saline (n = 20), (b) ultrasonic activation of saline (n = 20), (c) sodium hypochlorite (NaOCl) (n = 20), (d) ultrasonic activation of NaOCl (n = 15), (e) chlorhexidine digluconate (CHX) (n = 20) and one positive control group (n = 3) and one negative control group (n = 3). The amount of remaining Ca(OH)2 on the canal walls was measured under stereomicroscope with 30× magnification. Comparisons between groups were made by the non-parametric Kruskal-Wallis test and Dunn post-test at a significance level of p < 0.05.Results: There were no significant differences among the saline, ultrasonic activation of saline, NaOCl, ultrasonic activation of NaOCl and CHX (p > 0.05) groups.Conclusions: Irrigation solutions and ultrasonic activation of the irrigation solutions could not completely remove Ca(OH)2 from the simulated immature root canals.

Comparison of mineral trioxide aggregate and biodentine for management of open apices

Open apices are a constant challenge to an endodontist. This case report describes the management of open apices with periapical radiolucencies in maxillary central incisors. Mineral trioxide aggregate (MTA) and biodentine were used to form an apical barrier and further obturation was completed with the same. The rationale of this case report was to observe the effect of MTA and biodentine on periapical healing in the same patient. It was concluded that initial healing was better in the case of biodentine while long-term effect of MTA was better.CLINICAL RELEVANCE TO INTERDISCIPLINARY DENTISTRYThe rationale of endodontic treatment is to prevent and treat apical periodontitis. In this case, root was not completely formed and hence periodontium was not continuous. With root end closure using MTA and Biodentine, biomimetic activity was initiated which further led to healing of periapical radioluceny and bone formation. Proper coronal seal is inevitable to prevent leakage and further success of endodontic treatment. Hence, crown fabrication is important not only for esthetic purposes but for further long term success.

Comparing the Coronal Seal of Different Thicknesses of MTA with Gutta-Percha after Post Space Preparation.

Introduction. The aim of this study was to compare the coronal seal of different thicknesses of MTA with gutta-percha after post space preparation. Materials and Methods. A total of 50 maxillary central incisors randomly divided into 5 experimental groups (n = 8). After preparation of the root canals with step back technique, in groups 1 and 2, post spaces were prepared and 4 or 5 mm gutta-percha remained in the apical, respectively. In groups 3, 4, and 5, there was 1-2 and 3 mm MTA in the apical, respectively. The ten teeth serve as control groups. The teeth were connected to a bacterial microleakage evaluation system. The study period was 120 days and the samples were evaluated on ten-day intervals; Meier-Kaplan technique was used for estimation of the mean time of microleakage to occur. Log-rank test was used for comparison of microleakage. Results. Number of samples exhibiting microleakage in MTA was less than those of gutta-percha at all intervals. Means of days with no microleakage were maximum and minimum with 3 mm MTA and 4 mm gutta-percha, respectively. Conclusion. Obturation of root canals using the MTA technique provides a proper seal with the minimum thickness of MTA in teeth requiring post space preparation.

Coronal microleakage of three different dental biomaterials as intra-orifice barrier during nonvital bleaching.

This study was designed to assess the microleakage of glass-ionomer (GI), mineral trioxide aggregate (MTA), and calcium-enriched mixture (CEM) cement as coronal orifice barrier during walking bleaching. In this experimental study, endodontic treatment was done for 70 extracted human incisors without canal calcification, caries, restoration, resorption, or cracks. The teeth were then divided into three experimental using "Simple randomization allocation" (n = 20) and two control groups (n = 5). The three cements were applied as 3-mm intra-orifice barrier in test groups, and bleaching process was then conducted using a mixture of sodium perborate powder and distilled water, for 9 days. For leakage evaluation, bovine serum albumin marker was traced in a dual-chamber technique with Bradford indicator. The Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis. The mean ± standard deviation leakage of samples from negative control, positive control, GI, MTA, and CEM cement groups were 0.0, 8.9 ± 0.03, 0.47 ± 0.02, 0.48 ± 0.02, and 0.49 ± 0.02 mg/mL, respectively. Statistical analysis showed no significant difference between three experimental groups (P > 0.05). It is concluded that GI, MTA, and CEM cements are considered as suitable intra-orifice barrier to provide coronal seal during walking bleaching.

Pulp Revascularization- It's your Future Whether you Know it or Not?

Pulpal regeneration after tooth injury is not easy to accomplish. In teeth with immature apices and exposed vital pulp tissue, partial or complete pulpotomy is indicated to preserve pulpal function and allow continued root development. In many cases, injury causes loss of pulp vitality and arrested root development leading to a tooth with poor crown root ratio, a root with very thin walls, an open blunderbuss apex and development of apical pathosis. The ideal treatment in such cases would be to obtain further root development and thickening of dentinal walls by stimulating the regeneration of a functional pulp dentin complex. This outcome has been observed after reimplantation in avulsed immature permanent teeth but has been thought impossible in a necrotic infected tooth. This case series evaluates the efficacy of revascularization procedure in immature, non vital permanent teeth. Pulp regeneration was attempted in four patients at Department of Conservative Dentistry, ESIC Dental College, New Delhi using blood clotting approach. The cases were treated and followed up regularly at regular intervals ranging from 6 months to 3 years to assess the treatment response clinically and radiographically. The patients remained clinically asymptomatic with three out of four patients even responding positively to pulp responsiveness tests. Radiographic examination also revealed increased root formation and thickening of dentinal walls. It was concluded that the triad of a disinfected canal, a matrix (blood clot) in to which new tissue could grow and an effective coronal seal produced the desirable environment for successful revascularization.

Delayed tooth replantation: MTA as root canal filling.

MTA has been investigated as a root-end filling material. Its mechanism of action has some similarities to that of Ca(OH)2. The purpose of this study was to evaluate the repair process taking place in the delayed replantation of monkey teeth using calcium hydroxide and MTA as root canal filling materials. Five monkeys had their lateral incisors extracted and bench-dried for 60 minutes. After root canal preparation, the teeth were assigned to two groups according to root canal filling material: I, calcium hydroxide; and II, MTA. The same treatment sequence was followed for both groups: coronal seal, periodontal ligament removal, immersion of the tooth in 2% acidulated-phosphate sodium fluoride, irrigation of the socket with saline and replantation. Both groups exhibited replacement resorption, areas of ankylosis and absence of inflammatory root resorption. Statistically similar results (p > 0.05) were observed for both groups regarding replacement root resorption, but the groups differed significantly (p < 0.05) regarding the occurrence of ankylosis. MTA may be a viable clinical option for filling teeth submitted to delayed replantation, and is an acceptable option for treating replanted permanent teeth in order to prevent tooth resorption, particularly when dressing changes are not possible.

AN INVITRO COMPARATIVE EVALUATION OF FRACTURE RESISTANCE OF ENDODONTICALLY TREATED TEETH OBTURATED WITH RESILON AND GUTTA-PERCHA

Abstract Aim: To compare and evaluate in-vitro the fracture resistance of endodontically treated teeth obturated with resilon &amp; epiphany sealer and guttapercha using different sealers. Epoxy resin based sealer AH-plus and zinc oxide eugenol based sealer-TubliSeal (EWT). Methodology: sixty four human single rooted maxillary anterior teeth, cleaned stored in 0.9% saline. All the teeth were decoronated to root length 14mm and bucco-lingual diameter of 5-7mm, After access openings teeth were instrumented using K3.06 up to final apical size 30/.06 and randomly allocated into 4 experimental groups (n=16 per group). Group 1(Control group): teeth were instrumented but not obturated, Group 2: Resilon cones and epiphany SE-sealer. Group 3: guttapercha cones and epoxy based sealer AH plus. Group 4: guttapercha and Tubli seal EWT. Coronal seal was done using IRM cement. Each of the specimens were tested for fracture resistance by instron universal testing machine. Results: Higher fracture resistance values were observed for group 2 (Resilon &amp; Epiphany SE sealer) followed by group 3(Guttapercha &amp; AH Plus sealer) and group 4(Guttapercha &amp; TubliSeal EWT) when compared to group1 (control-instrumented but not obturated). Conclusion: filling the root canals with contemporary polymer based root canal obturating system- Resilon increased the in vitro fracture resistance of endodontically treated teeth.

Evaluation of the presence of Enterococcus Faecalis in root cementum: A confocal laser scanning microscope analysis.

Aim:The aim of this study is to address the cause of persistent infection of root cementum by Enterococcus faecalis.Materials and Methods:A sample of 60 human single-rooted teeth were divided into three groups. Group I (control group) had no access opening and one-third of the apical root cementum was sealed using varnish. Group II had no preparation of teeth samples. In group III, apical root cementum was exposed to organic acid and roughened using diamond point to mimic apical resorption. After access opening in groups II and III, all teeth samples were sterilized using gamma irradiation (25 kGy). E. faecalis broth was placed in the root canal and apical one-third of the tooth was immersed in the broth for 8 weeks with alternate day refreshment followed by biomechanical preparation, obturation and coronal seal. Apical one-third of all teeth samples were again immersed in the broth for 8 weeks with alternate day refreshment to mimic secondary infection. The samples were observed under a confocal microscope after splitting the teeth into two halves.Results:E. faecalis penetrated 160 μm deep into the root cementum in group III samples and only showed adhesion in group II samples.Conclusion:Penetration and survival of E. faecalis deep inside the cementum in extreme conditions could be the reason for persistent infection.

An in vitro evaluation of the effect of dentin deproteinization on coronal microleakage in endodontically treated teeth.

Background:The most common cause of failure of endodontic therapy is inadequate apical and coronal seal. Proper coronal seal reduces the risk of endodontic failure. Hence, the present study was done to test the role of self-etching primers in reducing microleakage through coronal seal.Materials and Methods:Following root canal preparation and obturation, 46 specimen teeth were subjected to one of the test methods as follows: Group I – deproteinization with 3% sodium hypochlorite and etching with 37% phosphoric acid; Group II – deproteinization with 3% sodium hypochlorite and chelation with 15% ethylenediaminetetraacetic acid (EDTA) (Glyde) without etching. Group I and Group II were further divided into two subgroups with 10 specimens in each: In subgroup A, Clearfil Liner Bond 2V was used and in subgroup B, Excite was used. Group III (obturated without access restorative material) had six specimens.Results:Spectrophotometric analysis was done to quantitatively analyze the amount of dye leakage. Microleakage values obtained in Group I and Group II were comparable. In Group I, marginally better values were obtained with the Clearfil Liner Bond 2V in comparison with Excite. In Group II, microleakage values obtained with Clearfil Liner Bond 2V and Excite were similar and statistically not significant. In Group III (control) where no access restoratives were placed, maximum leakage was observed.Conclusions:Maximum leakage values were observed in Group III, when obturated without access restorative and when exposed to artificial saliva. Clearfil Liner Bond 2V as a self-etching primer showed better values in preventing microleakage. Deproteinization may be important to reduce microleakage when using the fifth-generation bonding system (Excite) and sixth-generation bonding system (Clearfil Liner Bond 2V).

Intraorifice sealing ability of different materials in endodontically treated teeth: An in vitro study.

Background:Microbial contamination of the pulp space is one of the major factors associated with endodontic failure. Thus, in addition to a three dimentional apical filling a coronal seal for root canal fillings has been recommended.Aim:The present study was conducted to evaluate and compare the intra-orifice sealing ability of three experimental materials after obturation of the root canal system.Materials and Methods:Fourty single rooted mandibular premolars were decoronated, cleaned, shaped and obturated. Gutta-percha was removed to the depth of 3.5 mm from the orifice with a heated plugger. Ten specimens each were sealed with Light Cure Glass Ionomer Cement (LCGIC), Flowable Composite (Tetric N-Flow), and Light Cure Glass Ionomer Cement with Flowable Composite in Sandwich Technique along with a positive control respectively and roots submerged in Rhodamine-B dye in vacuum for one week. Specimens were longitudinally sectioned and leakage measured using a 10X stereomicroscope and graded for depth of leakage.Results:According to the results of the present study LC GIC + Tetric N Flow demonstrated significantly better seal (P < 0.01) than LC GIC. However there was no statistically significant difference in leakage (P > 0.01) between Tetric N-Flow and LCGIC+Tetric N-Flow groups.Conclusion:In the current study LCGIC+Tetric N-Flow was found to be superior over other experimental materials as intra-orifice barriers.

Management of tooth with failed regeneration procedure

Teeth with immature root development, necrotic pulps, and apical periodontitis present multiple challenges for successful endodontic treatment. Regenerative endodontics is a contemporary approach to managing these problems. Successful regeneration depends on a race between the new tissue and bacteria populating the pulp space and on the ability of the patient to heal the dental pulp tissues. Importance of prevention of bacterial entry into the root canal and maintaining proper coronal seal should not be overemphasized. Evidence suggests that mineral trioxide aggregate (MTA) apexification may be more beneficial for severely injured teeth than a regenerative endodontic procedure. Fiber posts, in combination with composite resin or with accessory fiber posts, can be recommended alternative to cast post and core in flared roots, due to the lower risk of catastrophic failures and better stress distribution. It is the tactic of choice for reinforcing structurally weakened roots as the function, and the prognosis of the restored root is improved, compared with the use of one single, inadequately fitting post. This report is about a case with failed regeneration procedure and managed with MTA apexification and multiple fiber posts to enhance its fracture resistance of maxillary central incisor. Clinical Relevance To Interdisciplinary Dentistry Mineral trioxide aggregate apexification may be more beneficial for severely injured teeth than a regenerative endodontic procedure Large diameter posts contribute more favorably to the fracture resistance of the root postcore-crown system than small diameter posts Fiber posts, in combination with composite resin or with accessory fiber posts, can be recommended alternative to cast post and core in flared roots, because of the lower risk of catastrophic failures and better stress distribution.

A COMPARATIVE EVALUATION OF EFFECT OF SODIUM HYPOCHLORITE ON MICROTENSILE BOND STRENGTH OF THREE DIFFERENT BONDING AGENTS TO THE LATERAL WALLS OF PULP CHAMBER: AN IN VITRO STUDY

The advent of adhesive materials has revolutionized the field of restorative dentistry. Lack of adhesion and sealing between the final restoration and tooth structure may lead to microleakage and ult imate failure of the restoration. These adhesive restorations are also being used in the field of endodontics. A good coronal seal is very important, since the penetration of microorganisms from a coronal direction can reinfect the root canal system and af fect the prognosis of the non - surgical root canal therapy. Coronal leakage is particularly significant in multi rooted teeth, in which accessory canal may allow inflammatory change to oc cur in the periodontal tissues from the pulp chambers . Improper restor ation can lead to loss o f endodontically treated teeth more than actual failure of endodontic therapy. The restorations with adhesive systems offer the advantage of transmission of functional stresses across the bonded interface to the tooth (mono bloc res toration) and potentially reinforce the weakened tooth structure . Bonding to pulp chamber lateral walls is different from bonding other dentinal surface. The structure of pulp chamber wall is complicated and not much is known about the bonding characterist ics of pulp chamber, it becomes essential to study the same. This study was done evaluate the effect of sodium hypochlorite on bond strength of bonding agent to the later al walls of the pulp chamber. However, chemical irrigants, such as sodium hypochlorite used in the endodontic treatment have been shown to affect the bond strength of resin composite to dentin adversely. Key W ords : microtensile bond strength, pulp chamber, microleakage, bonding agents, sodium hypochlorite

Stress analysis of different post‐luting systems: a three‐dimensional finite element analysis

The longevity of endodontically treated teeth is usually determined by the adequacy of root canal treatments, coronal seal and favourable stress distribution within the remaining tooth tissues. The aim of this study was to investigate the influence of post material and luting cement on the biomechanics of endodontically treated teeth using three-dimensional finite element analysis (3-D FEA). A 3 mm section of endodontically treated canine tooth was scanned and reconstructed for 3-D modelling and FE analyses. A metal post (MP) and a glass fibre post (GFP) were tested individually with four luting cements [zinc phosphate (ZPH), glass ionomer (GI), resin modified glass ionomer (RMGI) and resin based cements (RC)]. A push-out test was conducted by subjecting all models to 100 N perpendicular loading at the post. The maximum stresses generated along the MP-cement interface were significantly higher than corresponding stresses in the GFP-cement interface regardless of the cement type. GFP generated seven times higher stresses within the root dentine than metal posts when ZPH and GI were used, and three times higher when RMGI and RC were used. The displacement of GFP was double (50 μ) the displacement of MP (20 μ) in all groups. The low elastic modulus of GFP generated lower stresses along its interface and higher stresses within the root dentine, therefore the probability of debonding and root fracture in the GFP group was lower.

Revascularization of Immature Permanent Tooth with Periapical Lesion using a New Biomaterial - A Case Report

Aim: To describe a case of a necrotic immature mandibular central incisor with sinus tract and periradicular radiolucency that underwent revascularization using Biodentine as coronal sealing material. Summary: Revascularization procedures provide a more predicable outcome by rendering continued root development of immature apices. This case report describes the successful revascularization procedure on a mandibular incisor in a 15-year-old patient, with the resolution of the associated periapical pathology within 18 months. The tooth was treated using coronal root irrigation by 6% NaOCl and triple antibiotic paste without instrumentation. This conservative treatment approach combined with a coronal seal of a bioactive material like Biodentine can preserve the vitality of the dental pulp stem cells and create a suitable environment for pulp revascularisation, resulting in the completion of root maturation.

Microleakage: Apical Seal vs Coronal Seal

ABSTRACT Microorganisms can reach the dental pulp through the open cavity, dentinal tubules, gingival sulcus, periodontal ligament through a broken occlusal seal or faulty restoration of tooth previously treated by endodontic therapy or extension of a periapical infection from adjacent infected teeth. During operative procedures, these possible paths must be considered to prevent ingress. While endodontic therapy is being performed, these paths must be blocked to avoid contamination during and after the treatment. Well treated tooth might also fail if microorganisms reach the periradicular tissues. After root canal obliteration, care must be taken to ensure maintenance of the coronal as well as apical seal from contaminants. How to cite this article Amlani H, Hegde V. Microleakage: Apical Seal vs Coronal Seal. World J Dent 2013;4(2):113-116.

Canal Projection - A Technique for the Management of Badly Mutilated Teeth: Case Reports

Isolating a severely broken down tooth is a considerable challenge. Due to insufficient tooth structure either the rubber dam placement becomes difficult or the dam leaks. Coronal bonded build-up can simplify the endodontic phase and strengthen the tooth, decreasing the possibility of further damage to the tooth due to the rubber dam clamp or mastication. The canal projection technique allows for isolation of the individual canals bringing them to the cavosurface margin. This offers adequate visualization and convenience for instrumentation as straight line access is achieved and also provides a strong core and coronal seal of the operative field. In these case reports management of badly broken down teeth was done by canal projection technique using plastic delivering tips and hypodermic needles as projectors. Composite core build up was done, which helped in rubber dam placement.

An Evaluation of Coronal Seal of Root Canals Prepared by Different Systems

Aims: The aim of this in vitro study was to evaluate the coronal seal of root canals prepared by two NiTi systems. Materials and Methods: Thirty-six extracted human teeth with single root canal were decoronated at the cemento-enamel junction (CEJ). The working length was determined for each tooth. Thirty teeth were divided into three groups ten of each. Group I teeth were prepared by Pro-Taper NiTi rotary instruments, then obturated by matched-taper single cone. Group II teeth were prepared by Ra-Ce NiTi rotary instruments and obturated also by matched-taper single cone. Group III teeth were pre-pared by hand K-files instrument then obturated by gutta percha lateral condensation technique. Re-maining teeth were used as control group, three positive and three negative control. Tgadeseal was used as root canal sealer for all groups in this study. Dye penetration method was used to evaluate the coro-nal seal using a steromicroscope at 40X magnification. All teeth (experimental group and control groups) were longitudinally sectioned for examination of dye penetration. One-way analysis of vari-ance and Duncan's tests was used for statistical analysis. There was significant differences between the groups (p< 0.05). Results: Statistical analysis of the results demonstrated that there was no statistical significant difference in coronal seal between the two systems. While, there was a significant differ-ence between the two rotary Ni-Ti systems and the hand K-files instrument. Conclusion: The use of Ni-Ti rotary instrument for root canal preparation shows least coronal microleakage in comparision with hand K-files instrument.

Coronal sealing ability of different sealers on teeth obturation and the effectiveness of two different obturation techniques

Background and objectives: The purpose of this study was to evaluate the effect of two sealers on coronal seal and the coronal sealing ability of two obturation techniques. Methods: Forty extracted single–rooted human teeth were instrumented with the stepback technique and were irrigated with 5.25% sodium hypochlorite (NaOCl). The smear layer was removed by washing with 10 ml of 17% ethylene diamine tetra-acetic acid (EDTA) and 10 ml of 5.25% (NaOCl). All instrumented root canals were randomly divided into two experimental groups; Group A: 20 roots epoxy resin sealer (AH26) was used, Group B: 20 roots Zinc oxide euginol (ZOE) sealer was used. Each group of main groups were subdivided randomly into two obturation groups; 1. 10 roots obturated by thermo plasticized technique (obtura II), 2. 10 roots obturated by cold lateral compaction technique. The root surfaces were then coated with nail polish except for the coronal, then dye penetration study was conducted and samples were examined under the stereomicroscope. Data had been collected from three independent examiners and statistically analyzed using student t-test. Results: There were significant differences between AH26 with ZOE in group obturated by obtura II and when obtura II technique compared with the cold lateral compaction technique in group of AH26 sealer. Conclusion: Epoxy resin sealer (AH26) and obtura II gave the best results in coronal sealing when compared with Zinc oxide euginol sealer and cold lateral compaction technique.