A comparison of root fracture resistance using two root canal sealers. Effects of calcium phosphate endodontic sealers on the behavior of human periodontal ligament fibroblasts and MG63 osteoblast-like cells. Comparing subcutaneous tissue responses to freshly mixed and set root canal sealers Effect of photo-activated disinfection on bond strength of three different root canal sealers Effect of root canal sealers on bond strength of fibreglass posts cemented with self-adhesive resin cements. The effect of photodynamic therapy and polymer solution containing nano-particles of Ag /ZnO on push-out bond strength of the sealers AH-Plus and MTA Fillapex Effect of eugenol-containing sealer and post diameter on the retention of fiber reinforced composite posts Resistance to fracture of roots filled with different sealers. A comparative evaluation of the vertical root fracture resistance of endodontically treated teeth using different root canal sealers: an in vitro study. Evaluation of Effects on the Adhesion of Various Root Canal Sealers after Er:YAG Laser and Irrigants Are Used on the Dentin Surface. Push-out bond strength of root fillings made with C-Point and BC sealer versus gutta-percha and AH Plus after the instrumentation of oval canals with the Self-Adjusting File versus WaveOne. Drying protocol influence on the bond strength and apical sealing of three different endodontic sealers. In vitro fracture resistance of roots obturated with epoxy resin-based, mineral trioxide aggregate-based, and bioceramic root canal sealers. Resistance to Fracture of Dental Roots Obturated with Different Materials An in vitro comparison of the intraradicular dentin bond strength of Resilon and gutta-percha. The effect of two different root canal sealers and smear layer on resistance to root fracture. The effect of resin-based sealers on fracture properties of dentine. Fracture resistance of roots filled with gutta-percha or RealSeal®. Effect of retreatment on the push-out bond strength of MTA-based and epoxy resin-based endodontic sealers Epigallocatechin-3-gallate increased the push out bond strength of an epoxy resin sealer to root dentin. Cytotoxicity testing of endodontic sealers: a new method. Push-out bond strength of two new calcium silicate-based endodontic sealers to root canal dentine. A novel polyurethane-based root canal-obturation material and urethane-acrylate-based root canal sealer-part 2: evaluation of push-out bond strengths.
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 In regard to biological properties of  endodontic sealers  , there are many characteristics that should be considered . The aim of this study was to examine the biological effects of new calcium phosphate-based root canal sealers , CAPSEAL I and CAPSEAL II ( CPS ) , on human periodontal fibroblast cells by examining the expression levels of inflammatory mediators and to compare the effects of CPS on the viability and osteogenic potential of human osteoblast MG63 cells compared to those of other commercially available calcium phosphate sealers [ Apatite Root Sealer type I ( ARS I ) and Apatite Root Sealer III ( ARS III ) ; Sankin Kogyo , Tokyo , Japan ] and a zinc oxide eugenol-based sealer ( Pulp Canal Sealer EWT [ PCS EWT ] ; Kerr , Detroit , MI ) . The levels of IL-6 in the new CPS group ( CAPSEAL I , II ) were higher than those in the control and all experimental groups at all time points after 2 h. TGF-β1 and FGF-1 levels decreased at 72 h compared to the levels in the control , in cells treated with every sealers except ARS I. The new CPS sealers showed low cytotoxicity . Reverse transcription polymerase chain reaction showed that CAPSEAL I , II , and Apatite Root Sealer type III induced expression of early stage markers of differentiation ( alkaline phosphatase and osteopontin ) at 7 days . Also , new CPS showed higher mineralized nodule formation at 28 days . These results suggest that CAPSEAL I and II facilitate the periapical dentoalveolar and alveolar healing by controlling cellular mediators from PDL cells and osteoblast differentiation of precursor cells INTRODUCTION : The purpose of this study was to compare the subcutaneous tissue responses of freshly mixed or set endodontic root canal sealers ( i.e. RoekoSeal , AH26 , AH Plus ) in Wistar Albino rats . MATERIAL S AND METHODS : Seventy-two male albino rats weighing 200 - 250 g were used . The animals were r and omly divided into six groups of 12 rats each . Root canal sealers were implanted in subcutaneous tissue in both freshly mixed and set conditions . The animals were sacrificed after 7 , 14 , and , 60 days . After histological preparation and Hematoxylin and Eosin ( H&E ) staining , the specimens were evaluated for capsule thickness , severity and extent of inflammation , and necrosis . Results were statistically analyzed using Multivariate ANOVA test . RESULTS : Differences between set and freshly mixed root canal sealers were significant ( P=0.014 ) , but not significant between test material s and controls , except for capsule thickness and extent of inflammation between control and AH26 ( P=0.019 and P=0.006 respectively ) . The interaction between the type of material and setting condition was significant for capsule thickness and severity of inflammation in AH26 specimens at 14 and 60 days ( P=0.001 ) . CONCLUSION : Based on the results of this study assessing the biocompatibility , both set and freshly mixed states can be used . [ Iranian Endodontic Journal 2009;4(4):152 - 7 Introduction : The aim of this in vitro study was to evaluate the bond strength of Photo-Activated Disinfection ( PAD ) system to dentin with different root canal sealers by using a push-out test design . Material s and Methods : A total of 30 extracted m and ibular premolar teeth with single and straight roots were used . The crowns were removed and the root canals were prepared by using ProTaper rotary files . The smear layer was removed and the roots were r and omly divided into two groups ( n = 15 ) according to the use of PAD system as the final disinfecting agent . Each group was then divided into 6 ( n = 5 ) subgroups and obturated with gutta-percha and 3 different root canal sealers . The groups were Group 1 : Sodium hypochlorite ( NaOCl ) + ethylenediaminetetraacetic acid (EDTA)-AH Plus sealer ; Group 2 : NaOCl + EDTA + PAD-AH Plus ; Group 3 : NaOCl + EDTA-Sealapex ; Group 4 : NaOCl + EDTA + PAD-Sealapex ; Group 5 : NaOCl + EDTA-mineral trioxide aggregate (MTA)-Fiallapex ; and Group 6 : NaOCl + EDTA + PAD-MTA-Fillapex . 1-mm thickness horizontal sections ( n : 5 × 4 = 20 ) were sliced for the push-out bond strength measurement . Results : Group 3 and 4 showed significantly lower bond strengths compared with all the other groups ( P < 0.05 ) . No statistically significant difference was found among Groups 1 , 2 and 5 , but there was statistically significant difference between Group 5 and 6 ( P < 0.05 ) . Conclusion : This in vitro study indicated that the PAD system adversely affected the bond strength of the MTA Fillapex root canal sealer AIM This study evaluated the effects of different root canal sealers on the bond strength of a fibreglass post cemented with self-adhesive resin cements . METHODOLOGY The root canals of 50 extracted maxillary single-rooted canine teeth were prepared with the crown-down technique and r and omly divided into five groups according to the sealer used : group 1 : control group , gutta-percha points only ( no sealer ) ; group 2 : AH Plus ( resin-based sealer ) ; group 3 : self-etch Epiphany ( resin-based sealer ) ; group 4 : Sealer 26 ( calcium hydroxide-based sealer ) ; and group 5 : Endomethasone ( zinc oxide eugenol-based sealer ) . The root canals were filled with gutta-percha , the cold lateral compaction technique , except for group 3 where Resilon was used . Post spaces were prepared , and fibreglass posts were cemented with the self-adhesive cement RelyX Unicem . Bonded specimens were sectioned into 1-mm-thick slabs , and a push-out test was performed in a universal machine . Failure modes were observed and classified into five types : ( i ) adhesive between the post and resin cement ; ( ii ) mixed , with resin cement covering 0 - 50 % of the post diameter ; ( iii ) mixed , with resin cement covering 50 - 100 % of the post surface ; ( iv ) adhesive between resin cement and root canal ; and ( v ) cohesive in dentine . Data of bond strength were su bmi tted to anova and Tukey test ( α = 0.05 ) . RESULTS No significant difference was detected between control group , AH Plus , Epiphany and Sealer 26 ( P > 0.05 ) . The Endomethasone group had significantly lower bond strength values than the other sealers ( P < 0.05 ) . The prevalence of mixed fractures and adhesive cement-dentine failure was verified in the eugenol-containing sealer group ; in the control group , the resin-based and calcium hydroxide-based sealer groups , the predominant mode of failure was the mixed type . CONCLUSION Endomethasone interfered negatively with the bond to root dentine ; however , AH Plus , Epiphany and Sealer 26 did not interfere in the bond strength of a fibreglass post cemented with self-adhesive resin cements Background The aim of this in vitro study was to examine and compare the effect of photodynamic therapy and solution containing nano particles Ag/ZnO on adhesion of endodontic sealers to dentinal walls of human root canal . Material and Methods Ninty single-rooted human teeth were selected and their clinical crown was cut from the cemento-enamel junction zone . Canals were prepared by RaCe rotary system and the smear layer was removed using 17 % EDTA and 5.25 % NaOCl . Sample s were r and omly divided into two groups of AH Plus and MTA Fillapex based on the sealer type and each group based on antimicrobial method was divided into two sub-groups of photodynamic therapy and polymer containing nano particles of Ag / ZnO and a control sub-group ( N = 15 ) . After obturation of canals with gutta-percha and sealers mentioned , the sample s were incubated for a week at a humidity of 95 % and 37 ° C and then 2 mm thick discs were prepared from the middle region of roots for Push-out test . The maximum failure force was recorded in newton and converted to MPa . Then , 3 r and om specimens of each subgroup were evaluated by scanning electron microscopy . Statistical analysis was performed by Two way ANOVA and ( P<0.05 ) was considered significant . Results The highest ( 4.84 ± 1.63 ) and lowest ( 0.16 ± 0.075 ) push-out bond strength values were obtained in ( AH Plus-PDT ) and ( MTA Fillapex-Ag/ZnO ) respectively . Independent of antimicrobial method , AH Plus bond strength was significantly higher than the MTA Fillapex ( p<0.001 ) . For both sealers , PDT  increased the bond strength significantly ( p<0.001 ) . Conclusions Photodynamic therapy has a positive effect on the bond strength of AH Plus and MTA Fillapex sealers . Key words : AH Plus , MTA Fillapex , Nano particles , Photodynamic therapy , Push-out Background : Fiber reinforced composite ( FRC ) posts are cemented with resin cements . It is reported that using resin cements in canals sealed with eugenol-containing sealers reduces the post retention . However , there is controversy on the subject . Aims : The aim was to investigate the influence of eugenol-containing sealers and the amount of dentin removal from root canal with different post diameters on retention of FRC posts . Setting s and Design : It was an in vitro study Material s and Methods : The roots of sixty teeth were cut with 14 mm distance from the apex and were instrumented to the working-length of 13 mm . The teeth were r and omly distributed into 2 groups ( n = 30 ) . Following storage in normal saline for 7 days , the sample s in both the groups were further divided into 3 subgroups ( n = 10 ) . Canals in the experimental subgroups ( I , II , III ) were obturated by gutta-percha and eugenol-containing sealer ; and in the control subgroups ( IV , V , VI ) without any sealer . After storage in normal saline for 7 days , the post space was prepared by # 3 , # 2 , and # 1 drills of DT Light-Post system . Post was cemented with Panavia-F2.0 resin-cement . A composite core was built for each sample . All sample s were thermo cycled for 1000 cycles . The sample s were tested for post retention with a mechanical testing machine . Statistical Analysis : Data were analyzed by two-way ANOVA and Tukey-HSD test . Results : There was not a significant difference in retention between FRC posts # 1 and # 2 ( P > 0.05 ) . Post # 3 was more retentive than posts # 1 and # 2 ( P < 0.05 ) . ZOE sealer significantly reduced the retention of posts ( P = 0.024 ) , however , increasing post-space diameter significantly increased post retention in canals coated with ZOE sealer ( P = 0.002 ) . Conclusions : Eugenol-containing sealer reduced the retention of FRC posts cemented with resin cement . Removing more dentin from root-canals treated with eugenol-containing sealer for placing larger diameter posts caused an increase in post retention 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 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 INTRODUCTION The aim of this study was to evaluate the bond strength of various root canal sealers after various irrigation solutions and Er : YAG laser irradiation were used on root canal dentin . METHODS One hundred fifty freshly extracted human maxillary single-rooted teeth were used in this study . Teeth were sectioned transversally 4 mm below the cementoenamel junction . The root canal of each specimen was prepared using a tapered bur . Teeth were divided into 3 main groups by sealer ( AH Plus Jet [ Dentsply DeTrey , Konstanz , Germany ] , EndoSequence BC Sealer [ Brasseler , Savannah , GA ] , and Real Seal [ SybronEndo , Orange , CA ] ) and then divided into 5 subgroups by dentin treatment ( distilled water , calcium hydroxide , sodium hypochlorite , EDTA , and Er : YAG laser ) . The specimens were placed immediately at 37 ° C and 100 % humidity for 1 week . Then , the push-out test was applied . The maximum failure load was recorded in newtons and was used to calculate the push-out bond strength in MPa . Then , 3 r and om specimens from each group were examined under scanning electron microscopy . RESULTS The resin root canal sealers had higher push-out bond strength than the bioceramic sealer , and the differences were statistically significant ( P < .05 ) except in the sodium hypochlorite groups . The EDTA and Er : YAG laser applications removed the smear layer and increased the bond strength . The highest adhesion was observed in EDTA groups when each sealer was evaluated in itself . CONCLUSIONS The bonding strength of root canal sealers is influenced by their properties and various dentin surface treatments . The scanning electron microscopic study showed that although the dentinal tubules were open , at the profile examination the sealers did not penetrate into the dentin canals in all specimens AIM To compare the push-out bond strength exhibited by root fillings performed with either C-Point and Endosequence ® BC sealer ™ ( BC Sealer ) or gutta-percha and AH Plus ® after the instrumentation of oval canals with either the Self-Adjusting File ( SAF ) System or WaveOne ( WO ) reciprocating file . METHODOLOGY Eighty extracted premolars were selected and divided r and omly into the following four groups ( n = 20 ) : group 1 , SAF instrumentation and filling using gutta-percha and AH Plus sealer ; group 2 , SAF instrumentation and C-Point and BC sealer filling ; group 3 , WO instrumentation and filling using gutta-percha and AH Plus sealer ; and group 4 , WO instrumentation and filling with C-Point and BC sealer . Sodium hypochlorite ( 5.25 % ) and EDTA ( 17 % ) were used as irrigants for all groups . After the sealer was set completely , the teeth were prepared for micro push-out assessment using 1.0-mm-thick root slices . Loading was performed with a universal testing machine at a speed of 0.5 mm min(-1 ) . Two-way anova and Student 's t-test for pairwise comparisons were used to compare groups . RESULTS All specimens filled with C-Point and BC sealer were associated with significantly higher push-out bond strength compared with gutta-percha and AH Plus sealer ( P < 0.001 ) . The bond strength was higher for the coronal and apical sample s of the C-Point/BC sealer/SAF group ( 6.6 ± 0.3 and 3.2 ± 0.3 MPa ) versus those of the gutta-percha/AH Plus/WO group ( 4.8 ± 0.3 and 1.8 ± 0.3 MPa ) , by 38 % and by 80 % in the coronal and apical parts , respectively ( P < 0.001 , P < 0.0001 ) . Adhesive bond failure was more common in the WaveOne-instrumented group in general and in the buccal and lingual recesses in this group in particular . CONCLUSIONS In oval canals , the instrument used and the root filling material significantly affected the push-out values of root fillings . The highest value was recorded in oval root canals instrumented with the SAF System and filled with C-Point and BC sealer , whereas the lowest strength was noted in oval canals instrumented with WaveOne and filled with gutta-percha and AH Plus sealer The aim of this study was to evaluate the influence of drying protocol s ( DP ) on the apical sealing ( AS ) and on the bond strength ( BS ) of teeth filled with different  sealers .  The root canals of one hundred and fifty-six roots of maxillary canines were prepared with Reciproc rotary files ( R50 ) . The teeth were r and omly divided into four groups ( n = 39 ) , according to the DP : GI-paper points ; GII-70 % isopropyl alcohol + aspiration with NaviTip points ; GIII-95 % ethanol + paper points ; GIV-EndoVac + paper points . Each group was divided into subgroups , according to the sealer used : AH Plus , Sealapex and MTA Fillapex , using a single-cone technique . Evaluation of AS and BS was performed with fluid filtration ( FF ) and push-out ( PO ) methods , respectively . The PO test consisted of sectioning the roots , and subjecting a single slice from each third to testing and analysis for failure type . The data was su bmi tted to two-way and three-way variance analysis ( ANOVA ) and Tukey ( α = 5 % ) . The AS showed no drying protocol influence . The FF results revealed a statistically significant difference between MTA and Sealapex ( p < 0.05 ) sealers . The BS test values showed that there was no statistical significant difference among the canal thirds ( p > 0.05 ) , but that there was such a difference among the sealers ( p < 0.05 ) , among the protocol s ( p < 0.05 ) , and in the interaction between sealers and protocol s ( p < 0.05 ) . AH Plus revealed the highest BS values among the sealers ; the highest BS results for the sealers occurred with the specimens used with isopropyl alcohol , compared with ethanol and EndoVac 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 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 The purpose of this study was to compare the micropush-out bond strength of Resilon to that of gutta-percha . Extracted human anterior teeth were used for evaluation . The crowns were removed and the root canals were instrumented with Gates Glidden drills and 0.06 Profile rotary files . Instrumentation was performed with 5.25 % sodium hypochlorite irrigation and a final rinse of 17 % EDTA . The teeth were r and omly divided into two groups . Gutta-percha group : obturation with gutta-percha and Kerr Pulp Canal Sealer EWT . Resilon group : obturation with Resilon points , Epiphany Primer , and Root Canal Sealant . The teeth were cut perpendicular to their long axis to obtain a series of 1.0 mm thick disks ( n = 15 per group ) . Micropush-out bond strengths to root canal dentin were measured . The results show that the mean bond strength to root canal dentin was significantly higher ( p < 0.05 ) in the Resilon/Epiphany group as compared to the gutta-percha/Kerr Pulp Canal Sealer EWT group 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 ) 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 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 Background . Further studies on the adhesion properties of MTA-based material s seem necessary due to their growing use in endodontic treatment . This research aim ed to assess the effect of retreatment on the bond strength of MTA-based ( MTA Fillapex ) and epoxy resin-based ( AH Plus ) sealers . Methods . ProTaper rotary files were applied to prepare the root canals of 80 human m and ibular premolars . Then , the roots were r and omly divided intotwo groups of A ( n=40 ) and B ( n=40 ) , which were obturated with gutta-percha and MTA Filla-pex and AH Plus sealer , respectively . In both groups , the teeth were r and omly subdivided into 2 subgroups . No retreatment was carried out in subgroups A1 and B1 , while subgroups A2 and B2 were retreated with rotary files and a solvent . Then , a push-out test was performed on four 2-mm slices of each tooth at a distance of 2 mm from the coronal surface after two weeks of incubation . Data were analyzed with two-way ANOVA and statistical significance was set at P<0.05 . Results . Regardless of the procedure followed ( P<0.001 ) , significant differences were detected in the mean bond strength values between the two sealers . Irrespective of the sealer type ( P=0.3 ) , no significant differences were revealed by comparing the mean bond strength values of the study subgroups . Furthermore , no statistically significant interaction ( P=0.5 ) was found between the treatment and sealer types . Conclusion . AH Plus sealer exhibited a higher bond strength compared to MTA Fillapex . Retreatment using rotary files and chloroform had no statistically significant effect on the bond strength of sealers evaluated in this study This study aim ed to investigate the effect of epigallocatechin-3-gallate ( EGCG ) from green tea extract on the push out bond strength of an epoxy resin sealer to root dentin . Seventy single root canal premolars were decoronated and instrumented . The roots were r and omly irrigated with different final irrigation protocol s ( n=16 ) : 17%EDTA ( EDTA ) , 17%EDTA followed by 2.5%NaOCl ( EDTA+NaOCl ) , 17%EDTA followed by 1 mg/mL EGCG ( EDTA+EGCG ) and 1 mg/mL EGCG ( EGCG ) . Other six root canals were received only 2.5%NaOCl as a control group . One root from each group ( n=1 ) was excluded and prepared for SEM investigation . All root canals were then obturated and horizontally sectioned to perform the push out test . EDTA+EGCG group had the highest bond strength ( p<0.05 ) . EGCG group showed higher bond strength than EDTA group ( p<0.05 ) . The use of EGCG as a final irrigant significantly increased the push out bond strength of an epoxy resin sealer to root dentin The purpose of this study was to compare ISO st and ards versus a new technique for in vitro evaluation of cytotoxicity of root canal sealers . The cytotoxicity of AH Plus , Cortisomol , and Sealapex was first recorded according to ISO st and ards on L 929 fibroblasts by the MTT assay . In parallel , 30 single-rooted teeth were cut at the cementum enamel junction ( CEJ ) , and the roots were prepared and sterilized before filling with the lateral condensation using one of three sealers ( n = 10 ) . The apexes of the roots were dipped into 1 ml of minimum essential medium for 1 , 2 , and 30 days renewing the medium every other day . After 24-h contact between the medium and the filled roots , the medium was used to measure the cytotoxicity on L 929 with the MTT assay . ISO st and ards always gave a statistically higher cytotoxicity than the root-dipping technique ( p < 0.0001 ) , whatever the sealer and the exposure time . The ISO st and ards showed statistically significant differences among the sealers ( p < 0.0001 ) . AH Plus was noncytotoxic , Cortisomol showed a high cytotoxicity decreasing over time ( p < 0.001 ) , and Sealapex displayed a high cytotoxicity that did not decrease over time ( NS ) . The new technique showed statistically significant differences among the sealers ( p = 0.001 ) , but the differences were so small that they were likely not clinical ly relevant . The high cytotoxicity of Sealapex decreased over time but the cytotoxicity of AH Plus and Cortisomol did not . The results show that the ISO st and ards may strongly over-evaluate the cytotoxicity of the endodontic sealers , emphasize the difference among the sealers , and may clinical ly correspond to a large overfilling . The new technique reduces the discrimination of the test and may clinical ly correspond to a classical filling . Therefore , both methods might be considered as clinical ly relevant , corresponding to classical and overfilling conditions AIM To assess the push-out bond strength of two new calcium silicate-based endodontic sealers in the root canals of extracted teeth . METHODOLOGY Thirty extracted single-rooted central incisors of similar sizes were selected r and omly and distributed to three groups ( n = 10 ) . All canals were instrumented using ProTaper rotary instruments to achieve tapered canal walls . Irrigation was performed using 5 mL 2.5 % NaOCl between each instrument , and the smear layer was removed using 5 mL 17 % EDTA . The canals were filled with three different sealers using a cold lateral compaction technique : group 1 : AH Plus + gutta-percha , group 2 : I Root SP + gutta-percha and group 3 : MTA Fillapex + gutta-percha . Three horizontal sections were prepared at a thickness of 1 mm ± 0.1 in the apical , middle and coronal parts of each root . The test specimens were subjected to the push-out test method using a Universal Test Machine ( Instron , Canton , MA , USA ) that carried 1-mm , 0.5-mm and 0.3-mm plungers for coronal , middle and apical specimens , respectively . The loading speed was 1 mm min(-1 ) . The push-out data were analysed by two-way analysis of variance ( anova ) and the post hoc Holm-Sidak test , with significance set at P < 0.05 . RESULTS In the coronal specimens , there was no significant difference between the sealers . In the middle and apical segments , there was no significant difference between I Root SP and AH Plus groups . However , the I Root SP and AH Plus had significantly higher bond strength values than the MTA Fillapex ( P < 0.05 ) . In terms of root segments , the bond strengths in the middle specimens and the apical specimens were higher compared with the bond strengths in the coronal specimens ( P < 0.05 ) . There were no significant differences between the bond strengths in the middle and apical specimens . CONCLUSION MTA Fillapex had the lowest push-out bond values to root dentine compared with other sealers We have developed a visible-light curable urethane-acrylate/tripropylene glycol diacrylate ( UA/TPGDA ) oligomer to serve as a root canal sealer and a zinc oxide/thermoplastic polyurethane ( ZnO/TPU ) composite to serve as a root canal obturation material . The purpose of this study was to compare the push-out bond strengths of the following 8 groups of material s : ( 1 ) Tubliseal + gutta-percha ( TB/GP ) ; ( 2 ) Tubliseal + Resilon ( TB/R ) ; ( 3 ) Epiphany + gutta-percha ( EP/GP ) ; ( 4 ) Epiphany + Resilon ( EP/R ) ; ( 5 ) EndoREZ sealer + EndoREZ cone ( ES/EC ) ; ( 6 ) EndoREZ sealer + ZnO/TPU ( ES/PU ) ; ( 7 ) UA/TPGDA + EndoREZ cone ( UA/EC ) ; and ( 8) UA/TPGDA + ZnO/TPU ( UA/PU ) .  Eighty 1-mm-thick root slices prepared from extracted human permanent molars were r and omly divided into 8 groups with 10 specimens in each group . Root slices were filled with the above obturation material s , and then push-out test was performed with a universal testing machine . The results showed that the UA/EC and UA/PU groups had significantly higher bond strengths than the other groups
In general , studies suggest that root canal sealers elicit mild to severe toxic effects and that several factors may influence biocompatibility , e.g. , material setting condition and time , material concentration , and type of exposure .
4 ) Conclusions : The available evidence shows that root canal sealers exhibit variable toxic potential at the cellular and tissue level .
However , the method ological heterogeneity among studies included in this systematic review and the somewhat conflicting results do not allow a conclusion on which type of sealer presents higher biocompatibility .
( 1 ) Aim : To perform a systematic review of the literature on the biocompatibility of  root canal sealers  that encompasses the various types of sealers that are commercially available as well as both in vitro and in vivo evidence . (