maintaining the integrity of the natural dentition is important for proper function and natural esthetics .
one of them is perforation of root canal wall , which can significantly impact the long - term prognosis of the tooth .
furcation perforation refers to a mid - curvature opening into the periodontal ligament space and is the worst possible outcome in root canal treatment .
it has been reported that perforations were the second greatest cause of failure . to prevent bacterial contamination
an ideal perforation repair material should provide an adequate seal , be biocompatible , not affected by blood contamination , not be extruded during condensation , bactericidal , induce bone formation and healing , radiopaque , induce mineralization , cementogenesis and easy in manipulation and placement .
these materials include zinc - oxide eugenol cement ( intermediate restorative material , super- ortho ethoxy benzoic acid ) , glass ionomer cement , resin cements , resin  modified glass ionomer cement and mineral trioxide aggregate .
however , the divergent outcomes have demonstrated that so far no material has satisfied all the ideal requirements . today
, most preferred furcation repair materials are bioactive materials like mineral trioxide aggregate , biodentine .
recently , endosequence root repair material have been developed as ready to use , premixed bioceramic material recommended for perforation repair , apical surgery , apical plug , and pulp capping .
thus , the present study is designed to evaluate the sealing ability of micro - mega mineral trioxide aggregate , endosequence , and biodentine in repair of furcation perforations using dye extraction method .
forty extracted human mandibular molars with non - fused and well developed roots were used in this study .
they were then cleaned from any debris and washed under tap water and kept in normal saline until next step .
a standardized access cavity was prepared in every molar with a round bur # 2 , and the root canal orifices were located .
sticky wax was placed over the orifices of each canal and the sectioned root surface including pulpal floor .
it was then coated with two successive layers of varnish in an attempt to increase the marginal seal . to ensure each perforation
was centered between the roots , a black marker pen was used to mark the location of the defect .
artificial perforation of 1 mm in diameter was created from the external surface of the tooth with a # 2 round carbide bur mounted on a high - speed hand piece with air water coolant [ figure 1a ] .
group i : ten molars , in which perforations were left unsealed ( positive control ) .
group ii : ten molars , in which perforations were repaired with micro - mega mineral trioxide aggregate .
group iv : ten molars , in which perforations were repaired with biodentine [ figure 1b ] .
1a : pulpal floor view of perforation 1b : view of perforation from external surface 1c : placement of samples in petri dishes each group was placed in separate petri dishes containing 2% methylene blue such that all the teeth were immersed in dye up to the cej for retrograde dye challenge , and dye was added to access chamber of each teeth so that it was filled for orthograde dye challenge [ figure 1c ] .
after removal from the dye , teeth were rinsed under running water for 40 minutes and varnish was removed with a polishing disc .
the teeth were placed in vials containing 1 ml of concentrated ( 65 wt % ) nitric acid until complete dissolution .
two hundred l of the supernatant from each sample was then analyzed in a uv - visible spectrophotometer at 545 nm wavelength using concentrated nitric acid as the blank , and readings were recorded as absorbance units .
one - way anova and tukey 's multiple comparison test [ table 1 ] were done using the statistical package spss ( statistical package for social science , version 4 ) mean values of four different experimental groups
the mean absorbance values of experimental groups and controls in the current study showed that the positive control samples ( group i ) in which perforations were left unrepaired had the highest dye absorbance ( 0.87  0.09487 ) of all groups denoting the accuracy of the technique .
this was followed by biodentine ( group iv ) , which had dye absorbance values ( 0.49  0.07379 ) significantly higher than mm - mta ( group ii ) and endosequence ( group iii ) showed lower dye absorbance than remaining groups .
the perforations irrespective of location or etiology may interfere with the prognosis of endodontic treatment .
this iatrogenic or mechanical or pathological communication between root canal system and external tooth surface should be sealed with a biocompatible materials as soon as possible .
the present study evaluated the sealing ability of micro - mega mineral trioxide aggregate , endosequence , and biodentine as furcation repair materials in mandibular molars using a dye extraction leakage method .
dye penetration technique has long been used in endodontics because of its ease of performance and difficulty of other available techniques .
dye extraction methodology was employed in this study , which according to camps j and pashley gave similar results to the fluid  filtration technique as both are based on quantitative measurements of liquid passage within interfaces . in this study ,
an ultraviolet spectrophotometry was adopted since it is widely used technique because of its rapid analysis and the cost of the analysis is less expensive .
ultraviolet - visible spectrophotometry refers to absorption spectroscopy or reflectance spectroscopy in the ultraviolet - visible spectral region .
this means , it uses light in the visible and adjacent ( near - uv and near- infrared ) ranges .
the absorption or reflectance in the visible range directly affects the perceived color of the chemicals involved .
mineral trioxide aggregate was actually introduced as a root - end filling material ; however , because of its biocompatibility , it is now also considered as a material of choice to seal perforations .
however , mineral trioxide aggregate has certain drawbacks such as difficulty in handling and very slow setting reaction , which might contribute to leakage , surface disintegration , loss of marginal adaptation , and continuity of the material . in order to overcome these difficulties , micro - mega introduced endodontic repair cement micro - mega mineral trioxide aggregate .
it is a modified portland cement with added calcium carbonate , which allows the reduction of the setting time .
biodentine is a calcium silicate - based material that has polycarboxylate - based hydro - soluble polymer system described as water - reducing agent to reduce the overall water content of the mix , along with cacl2 as a setting accelerator .
endosequence is a bioceramic material composed of calcium silicates , zirconium oxide , tantalum oxide , calcium phosphate monobasic thickening agents , and proprietary fillers .
endosequence has been manufactured to overcome some of the difficult handling characteristics of mineral trioxide aggregate .
the manufacturers of endosequence material claim that premixed endosequence putty has a working time of approximately 30 + minutes , a setting reaction initiated by moisture and a final set achieved approximately four hours later with the calcium silicate portion of the material produces a calcium silicate hydrate gel and calcium hydroxide .
the water produced continues to react with the calcium silicates to precipitate additional gel like calcium silicate hydrate . according to the developers of the endosequence
, the water supplied through this reaction is an important factor in controlling the hydration rate and the setting time of this material .
shokouhinejad n et al . tested the bioactivity of endosequence by exposing the set material on phosphate - buffered saline .
endosequence has been shown to have negligible cytotoxicity and capability to induce cytokine expression . in the current study ,
a significant difference with this material is its particle size , which allows the premixed material to penetrate into the dentinal tubules and bond to adjacent dentin . according to ghattas sm et al . , endosequence root repair material showed sealing ability similar to white mineral trioxide when used as a root - end filling material . in the current study ,
another root repair material used is mm - mta ( micro - mega ) an endodontic repair cement , developed in order to overcome handling properties of mineral trioxide aggregate .
it is biocompatible , radiopaque material with properties like faster setting time , homogenous pasty consistency for easy handling and placement . in this study ,
micro - mega mineral trioxide aggregate showed less dye absorbance followed by endosequence but statistically no significant difference when compared with biodentine .
based on the results of this study , biodentine showed high dye absorbance than endosequence and micro - mega mineral trioxide aggregate .
, mechanical strength of biodentine is time - dependent ; at least two weeks are necessary to reach a final setting stage .
even after the initial setting , this material continues to improve in terms of internal structure towards a more dense material with a decrease in porosity .
within the limitations of this study , it was observed that endosequence showed better sealing ability in furcation repair when compared with other repair materials like micro - mega mineral trioxide aggregate and biodentine .
 aim : to evaluate the sealing ability of micro - mega mineral trioxide aggregate , endosequence , biodentine as furcation repair materials using a dye extraction leakage method.materials and methods : forty mandibular molars were randomly divided according to the material used for perforation repair . 
 group i- ( left unsealed ) control , group ii - micro - mega mineral trioxide aggregate , group iii - endosequence , group iv - biodentine . 
 all samples were subjected to orthograde and retrograde methylene blue dye challenge followed by dye extraction with 65% nitric acid . 
 samples were then analyzed using ultra violet ( uv ) visible spectrophotometer.results:biodentine showed highest dye absorbance , whereas endosequence showed lowest dye absorbance when compared with other repair materials.conclusion:within the limitations of this study , it was observed that endosequence showed better sealing ability when compared with other root repair materials . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSION