title: Comparison of Resilon and Gutta-Percha Filling Materials on Root Canal Fracture Resistance Following Restoring with Quartz Fiber Posts Evaluation of Fracture Resistance of Endodontically Treated Teeth Filled with Gutta-Percha and Resilon Obturating Material: An In Vitro Study Fracture resistance of roots obturated with novel hydrophilic obturation systems A comparison of root fracture resistance using two root canal sealers. Resistance to fracture of roots filled with different sealers. Fracture resistance of overtly flaring root canals filled with resin-based obturation material A comparative evaluation of the vertical root fracture resistance of endodontically treated teeth using different root canal sealers: an in vitro study. Influence of root embedment material and periodontal ligament simulation on fracture resistance tests. Effect of dentinal tubules and resin-based endodontic sealers on fracture properties of root dentin. The effect of resin-based sealers on fracture properties of dentine. Influence of periodontal ligament simulation on bond strength and fracture resistance of roots restored with fiber posts Resistance to Fracture of Dental Roots Obturated with Different Materials Effect of final irrigation procedures on fracture resistance of root filled teeth: an ex vivo study Fracture resistance of roots endodontically treated with a new resin filling material. In vitro fracture resistance of roots obturated with epoxy resin-based, mineral trioxide aggregate-based, and bioceramic root canal sealers. Gutta percha verses resilon: an in vitro comparison of fracture resistance in endodontically treated teeth. Fracture resistance of roots filled with gutta-percha or RealSeal®. The effect of two different root canal sealers and smear layer on resistance to root fracture. The properties of Endocal 10 and its potential impact on the structural integrity of the root. Fracture resistance of roots obturated with three different materials. Effect of final irrigation protocols on microhardness reduction and erosion of root canal dentin. Bonding of resin-based sealers to root dentin. Final Irrigation Regimens Affect Fracture Resistance Values of Root-filled Teeth. Effect of obturating systems, dowel materials, and adhesive luting techniques on the resistance to fracture of endodontically treated teeth. Effect of EDTA, sodium hypochlorite, and chlorhexidine gluconate with or without surface modifiers on dentin microhardness.
abstract: Objective : Bacterial leakage and root fractures are the most important reasons of root canal treatment failure . Due to the lack of adhesion of gutta percha to the canal walls , Resilon has been introduced as a root-filling material able to bond to the root walls . Metal posts may predispose the tooth walls to oblique and vertical fracture which usually leads to tooth loss ; whereas , fiber posts may reinforce the remaining tooth structure . The purpose of this study was to compare the effect of Resilon and gutta-percha on the fracture resistance of root canal following restoring with quartz fiber posts . Material s and Methods : Forty-four maxillary incisor root canals were chemo-mechanically prepared , then r and omly divided into three groups : 1-Control group ( n=20 ) , 2-Experimental group ( n=20 ) and a negative control group ( n=4 ) . Root filled teeth were restored with quartz fiber posts and composite resin cores .  Four teeth with a conservative prepared access cavities and without any further post preparation were used as a negative control group . After simulating the clinical situation , specimens were loaded in the Universal Testing Machine for compressive strength test . All data were statistically analyzed by the T-test . Results : The mean compressive strengths for group 1 was 535.8 ± 155.23 N and 645.93 ± 182.98N for group 2 , which were statistically significant ( p-value= 0.047 ) . Conclusion : Root canals filled with Resilon were significantly more resistant than that of gutta-percha , following restoration with quartz fiber posts Background : As per many studies endodontically treated teeth are widely considered to be more susceptible to fracture than vital teeth . Obturation strains and post placement have been a major cause of vertical root fracture . Present study was conducted to compare in vitro fracture resistance after filling with either Gutta-percha or Resilon by lateral condensation techniques in root canals . This study evaluated a new thermoplastic synthetic polymer based on polyester , which contains bioactive and radiopaque filler , Resilon performs every way as Gutta-percha except that it allows the bonding agent to attach to the resin core and the dentin wall thus forming a monoblock . Material s and Methods : In the present study 90 freshly extracted single-rooted human m and ibular premolar teeth endodontically treated , were cut at the cemento-enamel junction , and were r and omly divided into three groups of 30 each as teeth of Group A ( Control ) received no obturation , Group B teeth were obturated using Gutta-percha/AH26 , and Group C teeth were obturated using Resilon/Epiphany obturating kit . Each specimen were mounted in acrylic in a polyvinyl ring and then tested for fracture resistance with the help of an universal testing machine . A compressive force was applied until the root is fractured . The data were subjected to analysis of variance for comparing mean difference of fracture resistance among three groups . Multiple comparisons among these groups were carried out by non-parametric Kruskal – Wallis analysis . A p value of < 0.0001 was considered a statistically significant difference . Results : The results obtain after analysis showed no significant differences in the fracture resistance between the two tested groups of endodontic sealers . Conclusion : Within the limitation of the present in-vitro study , Resilon/Epiphany sealer performs better than Gutta-percha/AH 26 sealer with lateral condensation technique Aim : Comparative assessment of fracture resistance of roots obturated with three hydrophilic systems — novel CPoint system , Resilon/Epiphany system , and EndoSequence BC sealer ; and one hydrophobic gold st and ard gutta-percha/AHPlus system . Material s and Methods : Ninety freshly extracted , human , single-rooted m and ibular premolars were selected . The specimens were decoronated and st and ardized to a working length of 13 mm . The teeth were r and omly divided into six groups ( n = 15 ) . In Group A , teeth were left unprepared and unfilled ( negative control ) . Rest of the groups were prepared by using ProTaper system up to a master apical file F3 ; followed by which Group B was left unobturated ( positive control ) ; Group C , novel CPoint System ; group D , Resilon/Epiphany system , Group E EndoSequence BC sealer , and Group F gutta-percha and AH Plus . Specimens were stored for 2 weeks at 100 % humidity . Each group was then subjected to fracture testing by using a universal testing machine . The force required to fracture each specimen was recorded and the data was analyzed statistically using analysis of variance ( ANOVA ) test and Tukey 's post-hoc test . Results : The hydrophilic obturation systems have shown to exhibit significantly higher fracture resistance as shown by the values in Groups C , D , and E ( P < 0.05 ) when compared with Group F. Within hydrophilic groups there was significant difference between Group D and Groups C and E ( P < 0.05 ) , while Groups C and E had no significant difference ( P > 0.05 ) . Conclusion : In contrast to hydrophobic systems , hydrophilic systems showed higher fracture resistance in a single-rooted premolar AIM The aim of this study was to compare in vitro root fracture resistance following root canal filling with either Ketac-Endo or Roth 's root canal sealer . METHODOLOGY The roots of 40 teeth with single canals were instrumented and placed r and omly into four groups of 10 teeth . The prepared canals were obturated with lateral compaction using gutta-percha and Roth 's 801 sealer , lateral compaction and Ketac-Endo sealer or with a single cone and Ketac-Endo sealer ; the fourth group acted as unfilled controls . The roots were stored for 2 weeks in 100 % humidity prior to being mounted in acrylic resin blocks . A steel tipped rod attached to an Instron testing machine was positioned against the canal opening and a slowly increasing force was applied until root fracture occurred . The results were subjected to statistical analysis using Kruskal-Wallis one-way ANOVA . RESULTS There were no significant differences between the groups in terms of force required to vertically fracture the roots . CONCLUSIONS Under the conditions of this study , the use of Ketac-Endo sealer in conjunction with lateral compaction or single-cone obturation techniques does not increase the fracture resistance of root-filled teeth The aim of this study was to compare the fracture resistance of roots filled with gutta percha ( GP ) and different root canal sealers .  Fifty-five human maxillary central incisors were selected and r and omly divided into three experimental groups ( Groups 1 - 3 ) and two control groups ( Groups 4 and 5 ) . They were Group 1 - 15 root canals filled with an epoxy resin-based sealer ( AH Plus ) and GP , Group 2 -15 root canals filled with a calcium silicate-based sealer ( iRoot SP ) and GP , Group 3 : 15 root canals filled with another calcium silicate-based sealer ( MTA Fillapex ) and GP , Group 4 : five roots were instrumented but not filled , and Group 5 : five roots were neither instrumented nor filled . Compressive loading was carried out using a universal testing machine until fracture occurred . Force applied at time of fracture was recorded as fracture strength of specimen in Newtons . There were no significant differences in fracture strength among the three experimental groups ( p>0.05 ) , whose results were significantly superior to that of Group 4 ( p<0.05 ) . In conclusion , all the root canal sealers used in the present study increased the fracture resistance of instrumented root canals Background : Reinforcement of root canals obturated with Resilon was reported by several investigators , but no studies reported the reinforcement of overtly flared root canals obturated with Resilon material . The aim of this study was to investigate the fracture resistance of overtly flared root canals filled with Resilon as compared to similar root canals filled with gutta-percha ( GP ) . Material s and Methods : Sixty single-rooted premolars were divided r and omly into six groups . Group 1 served as control group . The control group was sub-divided into two groups , a negative group and a positive group . The negative group consisted of root canals that were only cleaned from residual pulpal tissues , however , the positive group had prepared and overtly flared root canals without obturation . Groups 2 and 4 were shaped using 0.04 taper rotary files , while groups 3 and 5 were shaped using 0.06 taper rotary files . Before obturation , the last four groups were further flared coronally with a reverse cone diamond bur . Groups 2 and 3 were obturated with GP and a resin-based sealer , while groups 4 and 5 were obturated with Resilon and Epiphany self-etching primer and Epiphany sealer . Roots were then fixed into a universal testing machine and vertically loaded until fracture . SPSS software ( Release 9.0 for Windows , SPSS , Chicago , USA ) was used to perform the statistical analysis . Results : Fracture resistance measurements showed that there were differences in resistance to fracture among the experimental groups ( ANOVA , P < 0.0001 ) . Mean values of the loading force applied to the negative control group were the highest at 1.81 KN , whereas the mean values for the Resilon groups ( Groups 4 and 5 ) at 1.13 KN and 1.54 KN were found to be higher than the GP groups ( Groups 2 and 3 ) at 0.45 KN and 0.88 KN , respectively . Tukey 's post hoc test showed that there was no statistical difference between the mean values of the negative control group and Group 5 ( P = 0.69 ) . Conclusion : Obturation of overtly flared roots with Resilon material increased the resistance of these teeth to vertical root fracture OBJECTIVE The objective of this study is to evaluate the vertical root fracture resistance of endodontically treated teeth obturated with - Tubli-Seal EWT/Gutta-percha , AH Plus/Gutta-percha , Epiphany SE sealer/Epiphany point . STUDY DESIGN Sixty-five single rooted premolars were decoronated and root length was 14 mm for each specimen . Fifty five teeth were enlarged up to ISO size 40 master apical file with stainless steel K-files using st and ardized preparation and remaining ten teeth were served as negative control . Then teeth were r and omly assigned into different groups depending on sealer used for obturation as follows : Group 1 : Negative control-no instrumentation was performed . Group 2 : Positive control-gutta-percha with out the use of any sealer . Group 3 : Experimental group-gutta-percha and Tubli-Seal EWT root canal sealer . Group 4 : Experimental group-gutta-percha and AH Plus . Group 5 : Experimental group-epiphany SE sealer and epiphany points . After 72 hours , the specimens were embedded in autopolymerizing resin leaving 7 mm of each root exposed and were subjected to fracture testing under universal testing machine at a crosshead speed of 1.0 mm per minute until the root fractured . Results were statistically analyzed using one-way ANOVA and independent t-test . RESULTS Showed that Epiphany SE sealer/Epiphany points showed highest mean fracture resistance and Tubli-Seal EWT group showed the least fracture resistance of all the material s tested . There was no statistically significant difference among experimental groups . CONCLUSION Epiphany SE sealer/Epiphany points demonstrated highest fracture resistance values than the other material s tested and intact tooth had highest resistance against vertical root fracture . CLINICAL SIGNIFICANCE Epiphany SE sealer/Epiphany points may be one of the material s of choice in the endodontic treatment of teeth The aim of this study was to evaluate the influence of the embedment material and periodontal ligament simulation on fracture resistance of bovine teeth . Eighty bovine incisor teeth were r and omized into 8 groups ( n = 10 ) , embedded in acrylic or polystyrene resin using 4 types of periodontal ligament simulation : 1 - -absence of the ligament ; 2 - -polyether impression material ; 3 - -polysulfide impression material ; 4 - -polyurethane elastomeric material . The specimens were stored at 370C and 100 % humidity for 24 hours . Specimens were su bmi tted to tangential load on the palatal surface at 0.5 mm/minute crosshead speed until fracture . The fracture modes were analyzed as follows : 1 - -coronal fracture ; 2 - -cemento-enamel junction fracture ; 3 - -partial root fracture ; 4 - -total root fracture . Statistical analyses by two-way ANOVA and Tukey 's test were applied ( p < 0.05 ) . The results showed that root embedment method and periodontal ligament simulation have a significant effect on fracture resistance . Artificial periodontal ligament modified the fracture modes OBJECTIVE To investigate the role of dentinal tubules in the fracture properties of human root dentin and whether resin-filled dentinal tubules can enhance fracture resistance . MATERIAL S AND METHODS Crack propagation in human root dentin was investigated in 200 microm thick longitudinal sample s and examined by light and scanning electron microscopy . 30 maxillary premolar teeth were prepared for work of fracture ( Wf ) test at different tubule orientations , one perpendicular and two parallel to dentinal tubules . Another 40 single canal premolars were r and omly divided into four groups of 10 each : intact dentin , prepared but unobturated canal , canal obturated with epoxy rein ( AH Plus/gutta percha ) , or with UDMA resin sealer ( Resilon/RealSeal . The sample s were prepared for Wf test parallel to dentinal tubules . Wf was compared under ANOVA with statistical significance set at p<0.05 . RESULTS Dentinal tubules influenced the path of cracks through dentin , with micro-cracks initiated in peritubular dentin of individual tubules ahead of the main crack tip . A significant difference ( p<0.001 ) was found between Wf perpendicular to tubule direction ( 254.9 J/m(2 ) ) vs. parallel to tubule direction from inner to outer dentin ( 479.4 J/m(2 ) ) . Neither canal preparation nor obturation using epoxy- or UDMA-based resins as sealer cements substantially influenced fracture properties of root dentin , despite extensive infiltration of dentinal tubules by both sealer cements AIM To determine whether resin-based sealer cements are able to strengthen root dentine , as measured by work of fracture ( Wf ) , micro-punch shear strength ( MPSS ) and resistance to vertical root fracture ( VRF ) . METHODOLOGY One hundred and twenty extracted premolar teeth were r and omly assigned amongst four treatments before testing : intact , root canals prepared but unfilled , or root filled using epoxy- or urethane dimethacrylate (UDMA)-based sealer ( plus core material ) . Sample s were then prepared for measuring Wf , MPSS or VRF using st and ard test procedures . Data were analyzed using one-way anova with significance set at P < 0.05 . RESULTS For all three tests , root canals filled using epoxy resin-based sealer were not statistically significantly different compared with UDMA resin ( P = 1 for Wf , P = 0.7 for MPSS and P = 0.12 for VRF ) , or different from both sound and prepared dentine ( P > 0.05 ) . There was also no significant difference between sound dentine and prepared dentine for both Wf ( P = 0.92 ) and resistance to VRF ( P = 1 ) . CONCLUSIONS Neither epoxy nor UDMA resins used as sealer cements enhanced fracture resistance of root dentine when placed within root canals of extracted teeth Objective Considering that periodontal ligament simulation may influence the stress distribution over teeth restored with intraradicular retainers , this study aim ed to assess the combined effect of mechanical cycling and periodontal ligament simulation on both the bond strength between fiber posts and root dentin and the fracture resistance of teeth restored using glass fiber posts . Material and Methods Ninety roots were r and omly distributed into 3 groups ( n=10 )  ( C-MC : control ; P-MC : polyether ; AS-MC : addition silicone ) to test bond strength and 6 groups ( n=10 )  ( C : control ; P : polyether ; AS : addition silicone , without mechanical cycling , and C-MC , P-MC and AS-MC with mechanical cycling ) to test fracture strength , according to the material used to simulate the periodontal ligament . For the bond strength test , fiber posts were cemented , cores were built , mechanical cycling was applied ( 2 × 106 cycles , 88 N , 2.2 Hz , and 45º incline ) , and the teeth cut into 3 slices ( 2 mm ) , which were then subjected to the push-out test at 1 mm/min . For the fracture strength test , fiber posts were cemented , cores were built , and half of the groups received mechanical cycling , followed by the compressive strength ( 45 ° to the long axis and 1 mm/min ) performed on all groups . Results Periodontal ligament simulation did not affect the bond strength ( p=0.244 ) between post and dentin . Simulation of periodontal ligament ( p=0.153 ) and application of mechanical cycling ( p=0.97 ) did not affect fracture resistance . Conclusions The material s used to simulate the periodontal ligament did not affect fracture or bond strength , therefore periodontal ligament simulation using the tested material s could be considered optional in the conditions of the study The aim of this study was to compare the vertical fracture resistance of roots obturated with different  root canal filling material s and sealers .  Crowns of 55 extracted m and ibular premolar teeth were removed to provide root lengths of 13 mm . Five roots were saved as negative control group ( canals unprepared and unfilled ) . Fifty root canals were instrumented and then five roots were saved as positive control group ( canals prepared but unfilled ) . The remaining 45 roots were r and omly divided into three experimental groups ( n = 15 root/group ) and obturated with the following procedures : in group 1 , glass ionomer-based sealer and cone ( ActiV GP obturation system ) ; in group 2 , bioceramic sealer and cone ( EndoSequence BC obturation system ) ; and in group 3 , roots were filled with bioceramic sealer and cone ( Smartpaste bio obturation system ) . All specimens were tested in a universal testing machine for measuring fracture resistance . For each root , the force at the time of fracture was recorded in Newtons . The statistical analysis was performed by using Kruskal-Wallis and post hoc test . There were no significant differences between the three experimental groups . The fracture values of three experimental and negative control groups were significantly higher than the positive control group . Within the limitations of this study , all material s increased the fracture resistance of instrumented roots AIM To evaluate the effect of chlorhexidine ( CHX ) on fracture resistance of roots treated with different concentrations of ethylenediaminetetraacetic acid ( EDTA ) . METHODOLOGY One hundred and twenty intact single-rooted premolar teeth were sectioned below the cementum-enamel junction to st and ardize the length of the teeth to 12 mm . The canals of one hundred specimens were instrumented with ProTaper Universal rotary instruments up to size F4 and were r and omly divided into five groups ( n = 20 ) according to the final irrigating solutions : Group 1 : distilled water ( DW ) ; Group 2 : 5 % EDTA and 2.5 % NaOCl ; Group 3 : 17 % EDTA and 2.5 % NaOCl ; Group 4 : 5 % EDTA , 2.5 % NaOCl , DW and 2 % CHX ; Group 5 : 17 % EDTA and 2.5 % NaOCl , DW and 2 % CHX . Root canals were filled with gutta-percha and epoxy resin-based root canal sealer using a single-cone technique . Twenty teeth served as negative controls and were not instrumented nor root filled ( Group 6 ) . All specimens were embedded in self-curing acrylic resin and loaded vertically at 0.5 mm min-1 until fracture occurred . The data were evaluated statistically using one-way anova test followed by Holm-Sidak 's multiple comparison test ( P < 0.05 ) . RESULTS Group 1 ( only DW ) had the lowest vertical fracture strength , followed by Group 3 ( 17 % EDTA and 2.5 % NaOCl ; P < 0.05 ) . Group 6 ( negative control group ) had the highest fracture resistance . Final irrigation with CHX following irrigation with 17 % EDTA or 5 % EDTA and 2.5 % NaOCl ( groups 4 and 5 ) significantly increased the fracture resistance of roots ( P < 0.05 ) . However , the difference between Group 4 and Group 5 was not significant ( P > 0.05 ) . CONCLUSIONS Intracanal CHX rinse of EDTA/NaOCl-treated root dentine enhanced the fracture resistance of roots filled with AH Plus BACKGROUND The authors evaluated the fracture resistance of endodontically treated teeth filled with either gutta-percha or a new resin-based obturation material .  METHODS The authors prepared and r and omly divided 80 single-canal extracted teeth into five groups : lateral and vertical condensation with gutta-percha , lateral and vertical condensation with the new resin-based obturation material , and a control group with no filling material . The specimens were stored in 100 percent humidity for two weeks , mounted in polyester resin and loaded to failure . RESULTS The authors found statistically significant differences among the experimental groups ( P < .05 ) . The groups with the new material displayed higher mean fracture loads and the gutta-percha groups lower mean fracture load values than the control unfilled group . However , the differences were not significant . The groups with the new material displayed significantly higher mean fracture loads than gutta-percha groups independent of the filling technique used . CONCLUSIONS Filling the canals with the new resin-based obturation material increased the in vitro resistance to fracture of endodontically treated single-canal extracted teeth when compared with st and ard gutta-percha techniques . CLINICAL IMPLICATION S ; If other properties of the new resin-based obturation material compare favorably with those of gutta-percha for filling the root canal , it should be considered as a replacement for gutta-percha , as the results of this study indicate that it could provide enhanced resistance to tooth fracture INTRODUCTION The aim of this study was to evaluate the fracture resistance of teeth filled with 3 different endodontic sealers . METHODS Seventy-five single-rooted extracted m and ibular premolars were decoronated to a length of 13 mm . The teeth were r and omly divided into 5 groups ( n = 15 for each group ) . In group 1 , the teeth were left unprepared and unfilled ( negative control ) , and in group 2 , the teeth were left unobturated ( positive control ) . The rest of the roots were prepared by using the ProTaper System up to a master apical file size of F3 : group 3 , bioceramic sealer ( Endosequence BC sealer ) + gutta-percha ; group 4 , mineral trioxide aggregate-based sealer ( Tech Biosealer Endo ) + gutta-percha ; and group 5 , epoxy resin-based sealer ( AH Plus Jet ) + gutta-percha . All root specimens were stored for 2 weeks at 100 % humidity to allow the complete setting of the sealers . Each specimen was then subjected to fracture testing by using a universal testing machine at a crosshead speed of 1.0 mm/min(-1 ) until the root fractured . The force required to fracture each specimen was recorded , and the data were analyzed statistically . RESULTS The fracture values of groups 3 and 5 were significantly higher than those of group 4 ( P < .05 ) . There was no significant difference between groups 3 and 5 ( P > .05 ) . CONCLUSIONS In contrast to Tech Biosealer Endo , Endosequence BC and AH Plus Jet sealer increased the force to fracture in root-filled single-rooted premolar teeth OBJECTIVE The aim of this study was to evaluate and compare the fracture resistance of endodontically treated teeth filled with gutta percha and Resilon  using lateral and vertical condensation methods . MATERIAL S AND METHODS A total of 75 freshly extracted single-rooted teeth were selected . All sample s were instrumented with profile 4 % Ni-Ti rotary instruments . Sample s were r and omly divided into five groups of 15 sample s each : Group 1 was obturated using lateral condensation with gutta percha and AH -26 sealer . Group 2 was obturated using vertical condensation with gutta-percha and AH-26 . Group 3 was obturated with Resilon and epiphany using lateral condensation technique . Group 4 was obturated with Resilon and epiphany using vertical condensation method . Group 5 received no filling . Restored teeth were subjected to compressive loading in a universal testing machine . RESULTS One-way ANOVA test showed significant difference among the groups ( P < 0.05 ) . The mean and SD values for the groups are as follows : Group 1 - ( 773.3 ± 148.1 ) , Group 2 - ( 769.9 ± 170.5 ) , Group 3 - ( 928.1 ± 135.4 ) , Group 4 - ( 902.6 ± 120.8 ) , and Group 5 - ( 766.0 ± 152.0 ) . It was seen that sample s of Group 3 showed the highest fracture resistance followed by Group 4 , Group 1 , and Group 2 . Group 5 showed the least fracture resistance . CONCLUSION Resilon-epiphany obturated roots using lateral condensation method showed higher fracture resistance  compared with gutta percha-AH 26 groups on vertical loading AIM To evaluate the vertical root fracture resistance of maxillary central incisors filled with different  root filling material s and sealers . METHODOLOGY Forty maxillary central incisor root canals were instrumented and divided r and omly into four groups . Each group was filled using lateral compaction , with gutta-percha and AH Plus , gutta-percha and RealSeal ( ® ) sealer , RealSeal ( ® ) cone and RealSeal ( ® ) sealer , or RealSeal ( ® ) cone and AH Plus , respectively . The roots were loaded vertically by a conical spreader tip inserted into the canal and attached to an Instron testing machine until root fracture occurred . The load at fracture and the pattern of fracture were recorded . Mechanical properties of both core material s were tested under compressive loading . Results were analysed statistically by two-way analysis of variance and post hoc Tukey 's tests . An independent sample t-test was used to compare the mechanical properties of the filling material s. RESULTS Load at fracture of roots  filled with gutta-percha and AH Plus ( 255 ± 74 N ) and gutta-percha and RealSeal ( ® ) sealer ( 237 ± 38 N ) was significantly greater than those filled using the RealSeal ( ® ) system ( 163 ± 29 N ) and RealSeal ( ® ) cone with AH Plus sealer ( 134 ± 17 N ) . Most fracture lines were in a bucco-lingual direction . In compressive tests of the core material s , RealSeal ( ® ) had greater flow in response to load than gutta-percha , suggesting more efficient transmission of forces to the canal wall in the fracture tests . CONCLUSIONS The lower fracture resistance of roots filled using RealSeal ( ® ) is probably the result of more efficient transmission of forces within the canal , rather than a direct effect of the material itself The purpose of this in vitro study was to test the effect of Ketac-Endo ( KE ) and AH 26 on resistance to root fracture and also to evaluate the effect of smear layer .  Seventy-two human maxillary canine teeth were r and omly divided into six groups ( n = 12 ) and were prepared using six different methods : group 1 : KE , without smear layer ( smear - ) ; group 2 : KE , with smear layer ( smear + ) ; group 3 : AH 26 , smear ( - ) ; group 4 : AH 26 , smear ( + ) ; group 5 ( negative control ) : nonprepared ; group 6 ( positive control ) : prepared but unfilled . After storing 1 week in 100 % humidity at 37 degrees C , the coronal lingual walls and root canal spaces were lowered 2 mm below the buccal walls of the roots . The sample s were placed into acrylic resin blocks so that 10 mm of buccal roots were exposed and were placed in a specially design ed steel pad at an angle of 15 degrees to the long axis of the root . A slowly increasing force was applied at the junction of the buccal wall and root canal space until fracture occurred . The force required to fracture each tooth was recorded as kg and statistically analyzed using one-way analysis of variance and Duncan tests . The results indicated that instrumentation of the root canals significantly weakened the tooth structure to fracture ( p < 0.05 ) . The canals obturated with either sealer were significantly stronger than roots whose canals were instrumented but not obturated ( p < 0.05 ) , and there was no difference between the sealers . The presence or absence of the smear layer did not cause any significant effect on the root fracture resistance of the teeth ( p > 0.05 ) The purpose of this research was to determine if the use of Endocal 10 ( previously called Biocalex 6.9 ) is associated with root fracture and to assess its sealability . Thirty-six freshly extracted , single canal human m and ibular incisors were instrumented and r and omly divided into two equal groups ( n = 15 ) . Canals in group A were obturated with vertically compacted gutta-percha and Sealapex , and those in group B were filled with Endocal 10 placed with a # 25 Lentulo spiral per manufacturer 's instructions . Two blinded investigators evaluated the teeth for fractures using transillumination and an operating microscope at 12 x magnification . Three of the fifteen sample s filled with Endocal 10 had vertically fractured in half , whereas none of the teeth filled with gutta-percha had any evident fracture lines . The remaining teeth were tested for leakage via a fluid filtration model at 1 wk and 30 days postobturation . No leakage was found among any of the sample s whether filled with gutta-percha or with Endocal 10 at either time interval . Statistical analyses were completed using Fisher 's exact test ( p = 0.023 ) , which showed that there was a significant increase in chance of fracture when using Endocal 10 versus gutta-percha . The results indicate that , although Endocal 10 is able to seal the tooth as well as gutta-percha and sealer , there is a significant potential risk of root fracture OBJECTIVE The aim of this study was to compare the fracture resistance of roots obturated with different material s. STUDY DESIGN Sixty root canals were instrumented and divided into 4 equal groups ( n = 15 each ) . The root canals in group 1 were filled with AH26 sealer and gutta-percha , in group 2 with Resilon and Epiphany , and in group 3 with Ketac-Endo Aplicap and gutta-percha .  Fifteen root canals had no obturation . The force required to fracture was recorded . The data was analyzed with analysis of variance and Duncan test . RESULTS The mean force of fracture for group 1 was significantly higher than for the other 3 groups ( P < .05 ) . There was significant difference between group 2 and group 3 ( P < .05 ) . Group 2 and group 3 were not significantly different from the control group ( P > .05 ) . CONCLUSION The use of AH26 + gutta-percha increased the fracture resistance of instrumented root canals compared with Resilon + Epiphany and Ketac-Endo Aplicap + gutta-percha This study aim ed to evaluate the effect of final irrigation protocol s on microhardness reduction and erosion of root canal dentin .  Sixty root canals from m and ibular incisors were instrumented and r and omly divided into six groups ( n = 10 ) according to the irrigant used : QMiX , 17 % EDTA , 10 % citric acid ( CA ) , 1 % peracetic acid ( PA ) , 2.5 % NaOCl ( solution control ) , and distilled water ( negative control ) . The chelating solutions were used to irrigate the canal followed by 2.5 % NaOCl as a final flush . After the irrigation protocol s , all specimens were rinsed with 10 mL of distilled water to remove any residue of the chemical solutions . Before and after the final irrigation protocol s , dentin microhardness was measured with a Knoop indenter . Three indentations were made at 100 µm and 500 µm from the root canal lumen . Afterwards , the specimens were prepared for scanning electron microscopic analysis and the amount of dentin erosion was examined . Wilcoxon and Kruskal-Wallis tests were used to analyze the results with a significance level set at 5 % . At 100 µm , all protocol s significantly reduced dentin microhardness ( p < .05 ) , while at 500 µm , this effect was detected only in the EDTA and QMiX groups ( p < .05 ) . CA was the irrigant that caused more extensive erosion in dentinal tubules , followed by PA and EDTA . QMiX opened dentinal tubules , but did not cause dentin erosion . Results suggest that QMiX and 17 % EDTA reduced dentin microhardness at a greater depth . Additionally , QMiX did not cause dentin erosion This study compared the microshear bond strength of three resin-based sealers to root dentin and assessed whether sealer cements behave differently in thin and thick films . Extracted maxillary premolars were sectioned buccolingually , and 45 root halves were r and omly allocated for microshear bond testing with the three resin sealers in thin and thick films . The microshear bond strength was then calculated in MPa . Failure modes were examined under light and scanning electron microscopy . Data were analyzed by using analysis of variance , with significance set at p < 0.05 . Overall , the epoxy resin-based sealers had the highest microshear bond strength to root dentin compared with urethane dimethacrylate-based sealers ( p < 0.001 ) . Bond strengths for the thick sealer group were significantly higher than the thin sealer group ( p < 0.001 ) and may reflect different patterns of behavior when the sealer is present as a thin layer INTRODUCTION The purpose of this study was to compare the effect of different final irrigation solutions on fracture resistance values ( FRVs ) of endodontically treated teeth . METHODS Eighty extracted decoronated human incisors were used . Ten r and omly selected roots were used as the negative control group . The remaining roots were prepared by the ProTaper system ( Dentsply Maillefer , Ballaigues , Switzerl and ) up to F2 . Ten prepared roots were selected as the positive control . The other prepared roots were divided into 6 ( n = 10 ) groups according to the final irrigation solution used : 5 mL saline , 17 % EDTA , EDTA with a surfactant ( REDTA ) , chlorhexidine , QMix ( Dentsply Tulsa Dental Specialties , Tulsa , OK ) , and BioPure MTAD ( Dentsply Tulsa Dental Specialties ) . In all groups , the final irrigation was performed for 1 minute except for the BioPure MTAD group ; in this group , it was applied for 5 minutes according to the manufacturer 's instructions . The specimens were filled with a single gutta-percha cone and AH 26 sealer ( Dentsply , De Trey , Konstanz , Germany ) . After being stored under 37 ° C and 100 % humidity for a week , the specimens were loaded in a vertical direction at 1 mm/min speed until they were vertically fractured . The results were analyzed by the Kruskal-Wallis and Siegel Castellan tests . RESULTS The negative control group showed the highest FRV . There were statistically significant differences between the negative and positive control groups ( P < .05 ) . Specimens irrigated with REDTA and QMix showed a higher FRV compared with the positive control group ( P < .05 ) . Specimens exposed to chlorhexidine and BioPure MTAD showed a lower FRV compared with the negative control group ( P < .05 ) . CONCLUSIONS Root canal preparation weakens the tooth . The final irrigation regimen has an impact on the FRV . A short time exposure to irrigation solutions ( REDTA and QMix ) that include surfactants probably contributed to the higher FRV , instead of a long time exposure as done with BioPure MTAD PURPOSE The aim of this study was to assess the role of obturating systems , dowel material s , and adhesive techniques on the resistance to fracture of endodontically treated teeth . MATERIAL AND METHODS Eighty maxillary central incisors were selected and r and omly divided into two groups according to the obturating system ( n = 40 ) ; group I : gutta-percha and Roeko sealer ; group II : RealSeal . Both groups were further subdivided into two subgroups ; subgroup A : using ceramic dowels ( Cosmopost ) ; subgroup B using fiber dowels ( Easy Post ) . Each subgroup was assigned to two divisions according to the adhesive luting technique ; division V ( total-etch ) Variolink II resin cement ; division U ( self-adhesive ) RelyX Unicem . Composite core build-up was made using a core former . Each specimen was loaded 2 mm from its incisal edge on the palatal side at a 135 ° angle with the long axis of the tooth using a universal testing machine with a load cell of 5 KN at a crosshead speed of 0.5 mm/min until fracture . Failure loads were recorded in N. Scanning electron microscopic examination at the dentin/resin interface ( 1000x ) was performed . Three-way ANOVA was used to test the effect of obturating system , dowel material , adhesive technique , and their interactions ( obturating system * dowel material , obturating system * adhesive , dowel material * adhesive , obturating system * dowel material * adhesive ) . Duncan 's test was used for pairwise comparison . The significance level was set at p≤ 0.05 . Statistical analysis was performed with SPSS 16.0 . RESULTS The mean resistance to fracture ( 617.4 N ) was statistically significantly higher in the ceramic dowel with gutta-percha and Variolink ( GP/C/V ) group than in the other groups . The RealSeal and RelyX fiber dowel  group 's mean resistance was the lowest and was significantly lower than the other groups . CONCLUSIONS In this study , three factors played a part in enhancing the resistance to fracture of endodontically treated teeth . High resistance to fracture was achieved when ceramic dowels were luted with total-etch technique in gutta-percha-obturated teeth INTRODUCTION This study aim ed to evaluate the effects of  root canal irrigants on the microhardness of root canal dentin in the presence and absence of surface-modifying agents . METHODS Forty-eight root halves were prepared by longitudinal splitting of the distal roots of 24 freshly extracted m and ibular human third molars and embedded in autopolymerizing acrylic resin , leaving the dentin surface exposed . After polishing , the microhardness values of the untreated dentin surfaces were recorded by using Vickers tester at the mid-root level . The root halves were r and omly assigned to 6 groups composed of 8 sample s each and treated for 5 minutes with one of the following irrigants : 17 % EDTA , REDTA , 2 % chlorhexidine gluconate ( CHX ) , 2 % CHX with surface modifiers ( CHX-Plus ) , 6 % NaOCl , or 6 % NaOCl with surface modifiers ( Chlor-XTRA ) . After surface treatment , dentin microhardness values were recorded at close proximity to the initial indentation areas . Experimental data were statistically analyzed by using the t test and one-way analysis of variance , followed by Tukey honestly significant difference test at α = 0.05 . RESULTS EDTA , REDTA , NaOCl , and Chlor-XTRA significantly decreased the microhardness of root dentin compared with intact controls ( P < .05 ) . CONCLUSIONS The addition of surface modifiers to the irrigants did not affect the microhardness of the sample
target: Although the majority of the studies reported that the use of root canal sealers increased the fracture resistance of endodontically treated teeth , conflicting evidence was found for the reinforcing effect of resin , glass ionomer , and calcium silicate-based sealers while there was moderate evidence for zinc oxide eugenol-based sealers in favor of no reinforcing effect .
  Conclusion On the basis of available evidence , the use of root canal sealer increases the fracture resistance of endodontically treated teeth .
  Regarding the comparisons among the sealers , no conclusions could be drawn for the superiority of one sealer type to another .
background: Objective The purpose of this study was to systematic ally review and critically analyze the published data of in vitro studies testing the effect of root canal sealers on the fracture resistance of endodontically treated teeth .