Ultrasonic Retrotips Research Articles

Comparison of the Microleakages of Four Root-End Filling Materials: An In Vitro Study.

When a nonsurgical endodontic treatment is ineffective, surgery is necessary. This entails putting a retrofilling to seal the tooth's apex. Exposing the lesion, performing a curettage, exposing the root apex, resecting it, preparing the root end, and lastly filling the cavity with the proper material are all steps in endodontic surgery. Thus, the aim of this study is to compare the apical microleakage of four root-end filling materials in cavities prepared using ultrasonic retro tip in in vitro conditions. An in vitrostudy was conducted on 60 extracted single-rooted teeth and was cut at the cementoenamel junction (CEJ). They were biomechanically prepared and obturated. Apical 3 mm root-end resection was done using a diamond disc. Root-end cavities were made using an ultrasonic retro tip. Teeth were separated into four groups and filled with SuperEBA®️ ethoxy-benzoic acid (EBA; Keystone Industries, New Jersey), mineral trioxide aggregate (MTA), Biodentine (Septodont, France), and TotalFill Bioceramic Root Repair Material (BC RRM; FKG Dentaire Sàrl, Switzerland). The samples were kept in methylene blue dye and split longitudinally. The degree of dye penetration was observed under a stereomicroscope and scored. Finally, the results were analyzed. TotalFill BC RRM and Biodentine showed the least apical microleakage (p <0.05).Group 1 samples had the highest mean microleakage, followed by Group 2, Group 3, and Group 4 samples. All of the sample groups showed some evidence of microleakage, but not all of the samples showed leaking. SuperEBA (Group 1) demonstrated the highest microleakage when compared to the other groups.

Impact of photodynamic therapy on the marginal adaptation of Biodentine used as root-end filling material.

The marginal adaptation of root-end filling materials and the effective antibacterial control in a surgical site are crucial for the successful outcome of endodontic surgery. This study aimed to evaluate the effect of retrograde application of photodynamic therapy on the marginal adaptation of Biodentine used as a root-end filling material. Twenty single-rooted anterior teeth were selected, instrumented and obturated with gutta-percha and AH Plus. The apical 3mm of the roots were resected and root-end cavities were prepared with an ultrasonic retro-tip. The teeth were randomly divided into two groups (n =10). In the first group, photodynamic therapy (PDT) was applied in the retrograde cavity prior to the root-end filling. In the second group retro cavity was filled without PDT. All specimens were obturated with Biodentine and afterwards sectioned longitudinally. The gap width at the material-dentin interface was measured using a scanning electron microscope. The results were statistically analyzed. The produced gap width by Biodentine/PDT was 3.85μm versus 2.68μm in the Biodentine control group with significant differences in-between. Under the conditions of this study, PDT has a negative effect on the marginal adaptation of Biodentine used as root-end filling material.

Comparing the efficacy of EndoSequence Root Repair Material, Biodentine, MTA angelus as retrograde filling in microbial leakage by Confocal Laser Scanning Microscope

This study aimed to compare the efficacy of EndoSequence ® Root Repair Materia, Biodentine, and MTA angelus® as root end filling in bacterial leakage and confirmed with Confocal Laser Scanning Microscope (CLSM). Methods: 55 maxillary single rooted teeth were used in this study. The teeth were decoronated at 16mm. root canals was prepared by using ProTaper rotary Ni-Ti instruments. Pro-taper F3 size Gutta-percha and AH plus sealer were used for single cone obturation technique. The root resection was done in the apex at 3 mm. The root end cavity was prepared by ultrasonic retro-tips. Samples were divided into 5 groups with 11 samples each according to retrograde cavities filling. Group1(EndoSequence), Group 2 (Biodentine). Group 3 (MTA angelus), Group 4 (Positive control), and Group 5 (Negative control). Dual chamber apparatus was prepared to test the retrograde filling leakage. The Enterococcus Faecalis in Confocal Laser Scanning Microscope under 20X magnification to measures of E. Faecalis penetration depth through retrograde materials. Results: EndoSequence® had better results in bacterial leakage and in penetration depth into the dentinal tubules with statisticallysignificant difference when compared to BiodentineTM and MTA angelus® (p ≤ 0.05). On other hand there was no any statistically significant difference between BiodentineTM and MTA angelus® (p>0.05) with more leakage in dual chamber whereas bacterial penetration into the dentinal tubules in CLSM was measured. Conclusions: EndoSequence showed better results in both bacterial leakage and in bacterial penetration.

Evaluation of microcrack formation after root-end preparation with two different types of ultrasonic retrotips and conventional bur: A stereomicroscopic study

Introduction: The aim of this in vitro study is to evaluate and compare the root-end cavities for the presence of microcracks after cavity preparation using two different ultrasonic (US) retrotips and conventional bur.Materials and Method: Thirty single-rooted teeth were instrumented and obturated. Three millimeters of apices were resected. Retrograde Class I cavities 3 mm deep were prepared on resected surfaces of ten teeth with diamond-coated US retrotip (Group 1), ten teeth with zirconium-nitride-coated US retrotip (Group 2), and ten teeth with conventional bur (Group 3). The root-end surfaces were examined under a stereomicroscope and the resected root surfaces were evaluated for the presence of microcracks on microphotographs.Results: Statistically significant difference was detected between diamond-coated and zirconium-nitride-coated US retrotips and also significant difference was detected when the same were compared with conventional bur for the presence of microcracks.Conclusion: Within the limitations of the study, it can be concluded that both zirconium-nitride- and diamond-coated retrotips produce more dentinal crack formation compared to conventional bur, but none of them produce a complete crack. Moreover, the diamond-coated retrotips produce less debris formation and minimal dentinal crack compared to zirconium-nitride-coated retrotips.

Surgical endodontic management after conventional root canal treatment failure: A case report

In the root canal system, infection of the pulp tissue caused by caries or other pathways is the primary cause of apical periodontitis. The ultimate goal of the endodontic treatment is to create adequate conditions for periradicular tissue healing. Nonsurgical endodontic treatment is a highly predictable treatment option in most cases, but surgery may be indicated for teeth with persistent periradicular pathosis unresponsive to nonsurgical approaches. The aim of this article is to highlight the possibility of the successful outcome of surgical endodontic treatment following failed non surgical treatment of right maxillary central incisor. With proper case selection and operator skill, periradicular surgery can be considered predictable, cost effective alternative to tooth extraction and tooth replacement. Keywords: Apicoectomy, Retreatment, Biodentine, Ultrasonic retrotips.

Effect of Blood Contamination on Marginal Adaptation of MTA and Endosequence Root Repair Material as a Retrograde Filling

Purpose: This study was designed to compare marginal adaptation of MTA and Endosequence Root Repair Material (ERRM) as retrograde filling materials. Materials and methods: 40 maxillary anterior teeth were prepared and obturated with gutta-percha and AH plus using lateral compaction technique. Apical 3mm of the roots were resected and retrograde cavities were prepared with diamond coated ultrasonic retrotip. Teeth were divided randomly into two main groups (I,II) according to blood contamination of retrograde cavities and every group then divided into two sub-groups (A,B) according to retrograde materials (MTA,ERRM). Teeth sectioned longitudinally and examined for marginal gap using SEM. Results: revealed that the high mean value in cavities without blood contamination and filled with MTA in group I and the high mean value in cavities smeed with blood contamination and filled with MTA in group II. There was no statistically significant difference between 4 groups. Conclusion: MTA and ERRM exhibited nearly comparable marginal adaptation in dry or blood environment.

The Effect of Root End Cavity Preparation Using Er,Cr:YSGG Laser, Ultrasonic Retrotip, and Bur on the Apical Microleakage of Retrograde Cavity Filled with MTA Plus.

ABSTRACTAim:The sealing ability of the retrograde material is greatly affected by the technique used for root end preparation. Advances in retrograde preparation techniques such as lasers has shown to provide an efficient outcome. The study was to evaluate and compare the effect of various techniques of retrograde cavity preparation on apical microleakage.Materials and Methods:Forty-five single rooted teeth were decoronated. Biomechanical preparation was carried out up to size F2 ProTaper system and obturated. Glass–ionomer cement was used as an access restorative material. The apical root resection was done at 3 mm from the apex at angulation of 90° to the long axis of the root. The allocation of the samples was done into three groups of 15 each. Group A: Retrograde cavities prepared using conventional round bur; Group B: Retrograde cavities prepared using ultrasonic retro preparation diamond tip; and Group C: Retrograde cavities prepared using “Erbium, chromium: yttrium, scandium, gallium, garnet” (Er,Cr:YSGG). The retrograde cavities hence prepared were filled with MTA Plus. Nail varnish was used to coat the samples except at the apical end. Samples were immersed in methylene blue for 24h. Stereomicroscope was used for examination of the sectioned teeth. The data were analyzed using one-way analysis of variance (ANOVA) and post hoc Tukey test.Results:Results showed very highly significant difference between laser and bur (P value = 0.001).Conclusion:Retrograde preparation with Er,Cr:YSGG showed significantly less microleakage when compared to the use of ultrasonic retrotip and burs.

An in vitro Comparative Evaluation of the Sealing Ability of Five Different Root-end Filling Materials under Confocal Laser Microscopy.

Aim:The purpose of this in-vitro study was to compare and evaluate the best sealing ability of five different root end filling materials i.e. Silver Amalgam, RMGIC, Cermet Cement, MTA Angelus and Biodentine using ConFocal Laser Scanning Microscope.Methods and Material:90 extracted caries free, maxillary incisor teeth were collected and were root canal treated using standardized technique. Apical root resections followed by retrograde cavity preparation were done with ultrasonic retrotip. The teeth were divided into six groups depending upon different root end filling materials (Amalgam, RMGIC, Cermet cement, MTA, Biodentine) and one control group and apical leakage was observed under confocal laser scanning microscope.Statistical Analysis Used:The data was analyzed by ANOVA and Post Hoc test.Results:The mean dye penetration of different groups were Group I (Control Group) 0.00±(0.00) mm, Group II (Silver amalgam) 3.00±(0.00) mm, Group III (RMGIC) 1.84±(0.26) mm, Group IV (Cermet cement) 1.83 (0.25) mm, Group V (MTA) 1.25±(0.12) mm, Group VI (Biodentine) 0.26±(0.21) mm.Conclusion:It was concluded that Biodentine exhibits best sealing ability followed by mineral trioxide aggregate, followed by Cermet Cement and RMGIC, whereas silver amalgam exhibited least sealing ability.

Evaluation of Push Out Bond Strength of Two Calcium Silicate Based Cements with Bone Cement in Retrograde Cavities Prepared by Ultrasonic Retro Tips

Evaluation of Push Out Bond Strength of Two Calcium Silicate Based Cements with Bone Cement in Retrograde Cavities Prepared by Ultrasonic Retro Tips

Clinical consideration and strategy on endodontic microsurgery

Root canal therapy is the most widely used method to treat the teeth with pulpal and periapical disorders. However, due to the complexity of root canal system, the existence of extraradicular biofilms and occurrence of true cyst, some teeth with pulpal and periapical diseases couldn't be treated effectively by non-surgical therapies. Then the combination of the surgical treatment, i.e., endodontic surgery, is necessary. The endodontic microsurgery, under the magnification and illumination provided by the dental operation microscope and with the proper use of micro instruments, ultrasonic retrotips and bioceramics root end filling materials, can treat the teeth with pulpal or periapical disorders precisely and less traumatically with high success rate. This article reviews the indications, contraindications, clinical strategy and latest advancement in endodontic microsurgery.

Comparative evaluation of push-out bond strength of root-end filling materials in root-end cavities prepared by laser or ultrasonic technique: An in vitro study.

Context:The use of mineral trioxide aggregate (MTA) and Biodentine as a root-end filling materials used in the root-end cavities prepared by laser or ultrasonic technique is a current topic in the branch of dentistry and push-out bond strength is used to measure the adhesiveness provided by the root-end filling materials.Aim:The aim of this study is to evaluate the push-out bond strength of MTA and Biodentine in root-end cavities prepared by erbium:yttrium-aluminium-garne (Er:YAG) laser and ultrasonic retrotip.Materials and Methods:A total of 40 extracted maxillary central incisors and canines were selected. Chemomechanical preparation and obturation were done. Root-end resections were performed followed by the root-end cavity preparation and root-end filling. Specimens were divided into four groups. Root-end cavities prepared by Er:YAG laser and filled with MTA, root-end cavities prepared by Er:YAG laser and filled with Biodentine, root-end cavities prepared by ultrasonic retrotip and filled with MTA and root-end cavities prepared by ultrasonic retrotip and filled with Biodentine, respectively. The apical end was again sectioned perpendicular to the long axis. The push-out bond strength was evaluated using a universal testing machine.Statistical Analysis Used:The data were analyzed using the analysis of variance and post hoc Tukey test.Results:Difference between push-out bond strength of root-end filling materials to root-end cavity walls prepared by laser and ultrasonic retrotips was statistically nonsignificant. Push-out bond strength of MTA and Biodentine did not differ significantly.Conclusion:Difference between push-out bond strength of MTA and Biodentine to root-end cavity walls prepared by Er:YAG Laser or ultrasonic retrotip were statistically nonsignificant.

Scanning electron microscopy evaluation of chitosan and carboxymethyl chitosan as retrograde smear layer removing agents.

Background:The smear layer acts as a physical barrier against penetration of root canal medicaments and sealers, thus compromising the seal leading to microleakage.Objectives:This study was conducted to evaluate the efficacy of 17% ethylenediaminetetraacetic acid (EDTA), 0.2% chitosan solution, and 0.2% carboxymethyl chitosan (CMC) used as smear layer removing agents in retrograde root canal preparation using scanning electron microscopy (SEM).Materials and Methodology:Eighty single-rooted teeth extracted for periodontal reasons were collected for the study. Root canals were prepared and obturated with gutta-percha coated with AH plus resin sealer. Apical 3 mm of each root resected and Class I retrograde preparation carried out using ultrasonic handpiece and ultrasonic retro tips to a depth of 3 mm along the root long axis. In Group 1 (control), normal saline solution alone was used for smear layer removal. In Group II, 17% EDTA, Group III and IV were treated with 5 ml of 0.2% chitosan and 0.2% carboxyl methyl chitosan, respectively, for 3 min. Blinded evaluation of specimens using SEM was performed independently by two operators who registered the amount of the smear layer present on the surface of the canal walls based on the score described by Hülsmann et al.Results:Group I (saline) was least efficient in the removal of the smear layer. Group II (17% EDTA), Group III (0.2% Chitosan), and Group IV (0.2% CMC) efficiently removed the smear layer from the retrograde cavity with mean scores 1.35, 1.60, and 1.35, respectively. Statistically, no significant difference found in Group II (17% EDTA), Group III (0.2% Chitosan), and Group IV (0.2% CMC).Conclusions:About 0.2% CMC and 0.2% chitosan can be better alternatives to 17% EDTA for smear layer removal due to their biological advantages.

Push-out bond strength of different tricalcium silicate-based filling materials to root dentin

The aim of this study was to evaluate the bond strength of different triccalcium silicate cements to retrograde cavity using a push out test. Thirty maxillary central incisors were shaped using #80 hand files and sectioned transversally. Root slices were obtained from the apical 4 mm after eliminating the apical extremity. The specimens were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. The samples were divided into three groups according to the root-end filling material (n = 10): MTA Angelus, ProRoot MTA and Biodentine. A gutta-percha cone (#80) was tugged-back at the limit between the canal and the root-end cavity. The root-end cavity was filled and the gutta-percha cone was removed after complete setting of the materials. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and push out testing was performed at a crosshead speed of 1.0 mm/min. There was no statistically significant difference in resistance to push out by the materials tested (p > 0.01). MTA Angelus and ProRoot MTA showed predominantly mixed failure while Biodentine exhibited mixed and cohesive failures. The tricalcium silicate-based root-end filling materials showed similar bond strength retrograde cavity.

Crack Formation Following Root-End Preparation in Roots with the Butterfly Effect.

Objective:To investigate apical cracks in roots that exhibit the butterfly effect and that have undergone apical resection and ultrasonic root-end cavity preparation. The effect of the obturation material was also studied.Methods:Forty extracted single-rooted teeth were decoronated at the cemento-enamel junction. Roots were viewed under a light microscope and coded according to the presence or absence of the butterfly effect. Canals were prepared using ProTaper Next instruments to size X3 and assigned to two obturation groups (gutta-percha and AH Plus, and ProRoot MTA alone). Each contained twenty roots (10 with the butterfly effect and 10 without the butterfly effect). Roots were resected perpendicular to their long axis, 3 mm from the apex, and cavities were cut using ultrasonic retrotips. Resin replicas were used for crack imaging from scanning electron micrographs. Statistical analyses were performed using Stata 13.1 (StataCorp, College Station, TX, USA).Results:Cracks occurred more frequently in teeth with the butterfly effect (80%), with this difference being significant (P=0.001). Most cracks (73%) ran buccolingually. Teeth obturated with MTA developed fewer cracks compared to those obturated with GP and sealer.Conclusion:Root-ends with the butterfly effect had a significantly higher number of buccolingual cracks following resection and ultrasonic root-end preparation. This might explain the development of some vertical root fractures, which usually run buccolingually. Canal obturation with MTA may be protective.

A Cone-beam Computed Tomographic Study of Apical Surgery–related Morphological Characteristics of the Distolingual Root in 3-rooted Mandibular First Molars in a Chinese Population

IntroductionApical surgery on the separate distolingual (DL) root of a 3-rooted mandibular first molar is thought to be difficult because DL roots are always severely curved, small, and shorter than distobuccal (DB) roots, and they are located far from the buccal cortical bone. The purpose of this study was to use cone-beam computed tomographic images to investigate the apical surgery–related morphological characteristics of DL roots in a Chinese population. MethodsThe screening process identified 83 subjects with 128 mandibular first molars with separate DL roots. The degree of root canal curvature was measured in the mesiodistal (MD) and buccolingual (BL) planes using the Schneider method. Distances were measured from the DL root apex to the buccal cortical bone, to the buccal cortical bone opposite the DB root apex, and to the buccal cortical bone opposite the mesiobuccal (MB) root apex. The lengths of the remaining DB, MB, and DL roots were measured after resection of 3 mm of the DL apical root. Angulations of the DL root canal were determined before and after DL apical root resection. ResultsThe teeth were classified into 3 types: type I, straight in the MD and BL planes; type II, straight in the MD plane and curved in the BL plane; and type III, curved in the MD and BL planes. Only 5 molars (3.9%) were classified as type I, whereas 52 (40.6%) molars were type II and 71 (55.5%) molars were type III. The type I DL root has a significantly shorter length and longer distance from the DL root apex to the buccal cortical bone than type II and III roots (P < .05). The distance from the DL root apex to the buccal cortical bone opposite the MB root apex is significantly longer than the distance to the buccal cortical bone opposite the DB root apex in types I and II (P < .05), whereas the distance is nearly equal for type III. The angulations for root-end preparation of types II and III DL roots vary from 57.5° to 129.1° and from 55.8° to 128.1°, respectively. ConclusionsA new classification was proposed for DL roots in 3-rooted mandibular first molars based on the root canal curvature. Type I is unsuitable for apical surgery. Access to the type II DL root apex should be through the DB root apex, whereas access to the type III DL root apex through the MB root apex is more feasible. Apical surgery on types II and III DL roots may be accomplished when the depth of the root-end preparation is reasonably reduced, and fine and personalized angulated ultrasonic retro tips are used.

Evaluation of the bond strength of root-end placed mineral trioxide aggregate and Biodentine in the absence/presence of blood contamination.

Objective:Mineral trioxide aggregate (MTA) has been accepted as an appropriate root-end filling material in endodontic microsurgery because of setting ability in the wet environment. The aim of this study was to assess the bond strength of root-end placed MTA and Biodentine (Septodont, Saint Maur des Fossés, France) in the absence/presence of blood contamination.Materials and Methods:Forty-eight single-rooted maxillary incisors were used. subsequent to root-end resection and apical preparation using ultrasonic retro-tips, the specimens were randomly separated into two groups according to the root-end filling materials: MTA (Cerkamed Medical Company, Stalowa, Poland) or Biodentine. The specimens were then separated into two subgroups according to storage condition (absence/presence of blood) (n = 12). After obtaining 2.0 ± 0.1 mm slices, push-out tests were performed. Each slice was examined under a stereomicroscope to evaluate the failure mode. The data were analyzed using two-way analysis of variance and Tukey's post hoc test for multiple comparisons. The failure modes were analyzed using the Chi-square test (P = 0.05).Results:The bond strength was significantly affected by the presence of blood contamination and root-end filling material type (P < 0.001). Biodentine had better bond strength than MTA (P < 0.001). The most common failure type was adhesive failure. According to the Chi-square test, there were no statistically significant differences among the groups (P = 0.394).Conclusions:Biodentine had better bond strength values compared to MTA, and the bond strength of both MTA and Biodentine as root-end filling materials was negatively affected by the presence of blood.

Sealing efficacy of mineral trioxide aggregate with and without nanosilver for root end filling: An in-vitro bacterial leakage study

BackgroundVarious materials have been added to mineral trioxide aggregate to enhance its properties. This study was aimed to compare the sealing efficacy of MTA with and without nanosilver using bacterial leakage approach.Material and MethodsSeventy canine teeth were prepared and obturated. Then, after apical resection, the root-end cavities were prepared by ultrasonic retrotips. Teeth were randomly divided into 4 groups containing two experimental groups (n=30) and two negative and positive controls (n=5). In group 1 and 2, root-end cavities were respectively filled with MTA and MTA with nanosilver (by 1% weight). Leakage assessment was carried out by bacterial leakage apparatus with Enterococcus faecalis species. Leakage comparison between experimental groups was done using Mann-Whitney test by Spss 16 software at significancy level of 0.05.ResultsThe median bacterial leakages for MTA and MTA with nanosilver were 19 and 2, respectively. The mean bacterial leakages for MTA and MTA with nanosilver were 30.06±28.67 and 9.66±14.25, respectively. Mann-Whitney test indicated that there was a significant difference in bacterial leakage day between two experimental groups (P=0.002).ConclusionsBased on the findings of this in-vitro bacterial leakage study, adding nanosilver to MTA decreased its sealing ability. Key words:Root canal therapy, root canal obturation, root canal filling materials, nanosilver, MTA.

Effects of antimicrobial photodynamic therapy and surgical endodontic treatment on the bacterial load reduction and periapical lesion healing. Three years follow up

Besides the advances in endodontics, there are situations in which surgery is necessary to retain a tooth that otherwise would be extracted. This study analyzes the microbial reduction after conventional periapical surgery followed by antimicrobial photodynamic therapy (aPDT) in 3 years follows up. Twenty-eight teeth needing periapical surgery were enrolled in this study. Microbiological samples were taken after: (1) accessing the lesion, (2) surgical procedure, and (3) aPDT. The teeth received a full mucoperiosteal flap, osteotomy with a high-speed bur, manual curettage of lesion and of the root, root-end resection and retrograde cavities prepared using ultrasonic retro-tips. After the conventional procedure the cavities received an aqueous solution of methylene blue (60 μM, 3 min) and were irradiated with a diode laser λ=660 nm (6 min, 15 J). After aPDT, a retrograde filling with mineral trioxide aggregate, flap re-positioning, and sutures conventionally ended the procedure. In all the cases, a periapical X-ray exam was taken before and after the surgical procedure. The microbiological samples showed an overall significant reduction, surgical procedure achieved a mean reduction of about 3.5 log while aPDT achieved a 5 log reduction. After 36 months of follow up the patients had, in average a reduction of 78% of the periapical lesion area. It appears that surgical endodontic treatment associated with antimicrobial photodynamic therapy highly improves the microbial reduction compared to the traditional technique and this could directly affect the treatment prognosis and periapical lesion healing.

New methodology to evaluate bond strength of root-end filling materials.

This study evaluated the bond strength of root-end filling materials to root-end cavities using a new methodology. Twenty maxillary central incisors were subjected to biomechanical preparation (#80 hand file) and sectioned transversally 2 mm short of the apex and 4 mm coronally to this point. The root cylinders were embedded in acrylic resin and positioned at 45° to the horizontal plane for preparation of root-end cavities with a diamond ultrasonic retrotip. Two groups (n=10) were formed according to the root-end filling material: MTA and Super EBA. A gutta-percha cone (#80) was tug-backed at the limit between the canal and the root-end cavity. The cavity was filled and the gutta-percha cone was removed after complete setting of the sealer. The specimens were placed in an Instron machine with the root-end filling turned downwards. The push-out shaft was inserted in the space previously occupied by the gutta-percha cone and run at a crosshead speed of 1.0 mm/min for pushing out the root-end filling material. Data were analyzed by ANOVA (α=5%). Super EBA (6.03±1.31) presented higher bond strength (MPa) than MTA (1.81±0.45) (p>0.05). There was a predominance of cohesive failures for Super EBA and mixed for MTA. The protocol of specimen preparation is effective and introduces a specific methodology for assessing bond strength of root-end filling materials to dentin. Among the materials, Super EBA presented the highest bond strength.

Microleakage evaluation around retrograde filling materials prepared using conventional and ultrasonic techniques.

The importance of the retrograde cavity preparation and the material used to restore is of utmost importance to achieve successful surgical endodontics. The aim of the present study is to evaluate the apical micro-leakage of root end cavities filled with Mineral trioxide aggregate, Biodentine and light cure GIC using two different cavity preparation techniques that is conventional bur preparation and ultrasonic tip preparation. Eighty extracted single rooted human teeth (except mandibular incisors) with one canal, fully developed apices and without any major carious lesion are collected for the study. The teeth were sectioned at CEJ to standardize the length. Roots are instrumented upto master apical file 40 K size and obturated with gutta percha and AH plus sealer in lateral condensation technique. The teeth were then resected apically at 90° angle axis to the long axis of the root removing 3 mm of the apex. The teeth were divided in to four groups of 20 each- • Group I- samples restored with MTA. • Group II- samples restored with Biodentine. • Group III- (Positive control group)- samples restored with Light activated GIC. • Group IV - (negative control group)- no filling material. Each group is divided into two subgroups (a, b) of ten teeth each 1. Retropreparation done with ultrasonic retrotip. 2. Retropreparation done with conventional bur. The teeth were then immersed in 0.5% Rhodamine B dye for 48 h. The teeth were split longitudinally and the interface between the restored material and the canal wall is observed under Confocal laser scanning microscope. Depth of dye penetration was examined under stereomicroscope. The statistical analysis was performed by One way ANOVA, t test. Pair wise comparision was done by Newman - Keuls multiple post hoc test. The mean values of Dye penetration for Group Ia (321.23), Group Ib (490.11), Group IIa (1065.14), Group IIb (1170.96), Group IIIa (1888.90), Group IIIb (2025.35). The samples prepared with ultrasonic retrotip showed less microleakage but it is statistically not significant. MTA showed significantly less microleakage when compared to Biodentine and light cure GIC and there is no statistical difference between the ultrasonic retrotip preparation and conventional bur preparation.