retrograde filling consists in the preparation and filling of an apical cavity with an 
 appropriate material . in the search 
 for a biocompatible material capable of inducing mineralized apical tissue formation , 
 calcium hydroxide ( ch ) has been included in the formulation of filling 
 materials . in order to 
 stimulate mineralized tissue formation , the filling material should be able to increase 
 the ph and release of calcium ions ( ca ) . sealer 26 is an epoxy resin - based cement containing ch that can be used for retrograde 
 filling if prepared with a higher powder / resin ratio than when used as a root canal 
 sealer . , petrpolis , rj , brasil ) in 
 retrograde fillings in dogs ' teeth and observed similar periapical repair with sealer 
 26 , proroot mta ( tulsa dental , johnson , tn , usa ) , and sealapex ( kerr corp . , orange , ca , 
 usa ) with zinc oxide . some studies have shown lower rates of ph increase and 
 ca release for sealer 26 compared to other ch - containing 
 cements . however , in these studies , sealer 26 was prepared using 
 the powder / resin ratio recommended for its use as a root canal sealer . mta a retrograde filling material composed of tricalcium silicate , tricalcium aluminate , 
 and other mineral trioxides , shows adequate sealing ability in retrograde 
 fillings and in the treatment of root perforations . this material is also biocompatible when used in retrograde 
 filling and root canal perforations . its presence allows 
 greater adhesion between the endodontic filling materials and the root canal 
 walls . ( 2006 ) evaluated 
 the seal promoted by the resilon / epiphany system , pro root mta , and super - eba as 
 retrograde filling materials , and observed less bacterial leakage for resilon and mta 
 compared with super - eba . ( 2004 ) proposed the 
 addition of ch to ah plus cement in order to reduce its flowability . we suggest that ch 
 can be added to epiphany to attain thicker consistency , facilitating its use as a 
 retrograde filling material . therefore , the present study aimed to evaluate 
 the ph increase and calcium ion release of epiphany cement and the epiphany - ch 
 association , compared to other cements used in retrograde filling . the following materials , containing either ch or calcium oxide , were evaluated ( figure 1 ) . materials used in the study , their compositions and manufacturers for ph and calcium ion release evaluation , 10 specimens were prepared from each 
 material studied . sixty polyethylene tubes measuring 1 cm in length and 1.5 mm in 
 diameter were filled with the cements to be evaluated . sealer 26 ( g1 ) was prepared in a 5:1 powder/ resin ratio , according to 
 tanomaru - filho , et al . white mta ( g2 ) was prepared in a powder/ liquid ratio of 0.33 g/1 g . after weighing the two paste components , 10% 
 or 20% ch ( ch ) was added to the epiphany sealer , resulting in the materials derived 
 from epiphany evaluated in g4 and g5 , respectively . zinc oxide and eugenol cement was 
 prepared in a powder/ liquid ratio according to bernab , et al . ( 2005 ) . immediately after preparing the materials and filling the tubes they were placed in 
 lidded flasks ( jprolab , so jos dos pinhais , pr , brazil ) containing 10 
 ml distilled water with neutral ph and kept in an oven at 37c . after 2 , 6 , 12 , 24 , 
 and 48 h , 7 , 14 , and 28 days , the tubes containing the cements were placed in new flasks with 10 ml of distilled 
 water for further analyses in the different time periods . ph readings were performed with an ultrabasic ph meter ( denver instrument company , 
 arvada , co , usa ) , previously calibrated using substances with phs 4 , 7 , and 
 10 . ca release was monitored with an h1170 hilger & watts atomspeck 
 atomic absorption spectrophotometry ( rank precision industries ltd . analytical 
 division , london , uk ) equipped with a calcium atom - specific hollow cathode lamp 
 ( wavelength = 422.7 nm and current = 20 ma ) , 0.7 nm slit and 5.0 cm burner 
 length . ca ion release readings were compared to a standard curve obtained by 
 diluting calcium at 1.0 , 2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0 , 8.0 , 9.0 , 10.0 , 15.0 , 20.0 , 
 and 25.0 ppm ( calcium standard solution , merck , darmstadt , germany ) in ultra - pure 
 water . data were subjected to statistical analysis by anova and individual comparisons were 
 performed using the tukey - kramer method . a significance level of 5% for ph and calcium ion release evaluation , 10 specimens were prepared from each 
 material studied . sixty polyethylene tubes measuring 1 cm in length and 1.5 mm in 
 diameter were filled with the cements to be evaluated . sealer 26 ( g1 ) was prepared in a 5:1 powder/ resin ratio , according to 
 tanomaru - filho , et al . white mta ( g2 ) was prepared in a powder/ liquid ratio of 0.33 g/1 g . pure epiphany ( g3 ) was prepared 
 using equal measurements of both pastes . after weighing the two paste components , 10% 
 or 20% ch ( ch ) was added to the epiphany sealer , resulting in the materials derived 
 from epiphany evaluated in g4 and g5 , respectively . zinc oxide and eugenol cement was 
 prepared in a powder/ liquid ratio according to bernab , et al . ( 2005 ) . immediately after preparing the materials and filling the tubes they were placed in 
 lidded flasks ( jprolab , so jos dos pinhais , pr , brazil ) containing 10 
 ml distilled water with neutral ph and kept in an oven at 37c . after 2 , 6 , 12 , 24 , 
 and 48 h , 7 , 14 , and 28 days , the water was assessed for ph and calcium ion release . the tubes containing the cements were placed in new flasks with 10 ml of distilled 
 water for further analyses in the different time periods . ph readings were performed with an ultrabasic ph meter ( denver instrument company , 
 arvada , co , usa ) , previously calibrated using substances with phs 4 , 7 , and 
 10 . ca release was monitored with an h1170 hilger & watts atomspeck 
 atomic absorption spectrophotometry ( rank precision industries ltd . analytical 
 division , london , uk ) equipped with a calcium atom - specific hollow cathode lamp 
 ( wavelength = 422.7 nm and current = 20 ma ) , 0.7 nm slit and 5.0 cm burner 
 length . ca ion release readings were compared to a standard curve obtained by 
 diluting calcium at 1.0 , 2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0 , 8.0 , 9.0 , 10.0 , 15.0 , 20.0 , 
 and 25.0 ppm ( calcium standard solution , merck , darmstadt , germany ) in ultra - pure 
 water . ph readings were performed with an ultrabasic ph meter ( denver instrument company , 
 arvada , co , usa ) , previously calibrated using substances with phs 4 , 7 , and 
 10 . ca release was monitored with an h1170 hilger & watts atomspeck 
 atomic absorption spectrophotometry ( rank precision industries ltd . analytical 
 division , london , uk ) equipped with a calcium atom - specific hollow cathode lamp 
 ( wavelength = 422.7 nm and current = 20 ma ) , 0.7 nm slit and 5.0 cm burner 
 length . ca ion release readings were compared to a standard curve obtained by 
 diluting calcium at 1.0 , 2.0 , 3.0 , 4.0 , 5.0 , 6.0 , 7.0 , 8.0 , 9.0 , 10.0 , 15.0 , 20.0 , 
 and 25.0 ppm ( calcium standard solution , merck , darmstadt , germany ) in ultra - pure 
 water . data were subjected to statistical analysis by anova and individual comparisons were 
 performed using the tukey - kramer method . a significance level of 5% the mean ph values of the cements evaluated in the various experimental periods are 
 shown in table 1 . sealer 26 presented the 
 highest ph value in the initial periods ( 3 and 6 h ) . after 12 h , sealer 26 and epiphany 
 + 20% ch had equivalent results . from 7 through 14 days , white mta and sealer 26 had the 
 highest ph values , followed by epiphany with 10% and 20% ch . at 28 days , all materials 
 had similar results , except for zinc oxide and eugenol ( zoe ) . in all the experimental 
 periods zoe had the lowest ph values ( p<0.05 ) . mean  standard deviation of hydroxide ions ( ph ) released from the 
 materials studied after different periods of time ( a , b , c , d ) in each period , means values followed by different labels are 
 statistically different ( p<0.05 ) . the mean ca ion release values for all cements evaluated are shown in table 2 . ca release at 3 and 6 h was 
 greater for sealer 26 . from 12 h through 14 days , epiphany with 10% and 20% ch had the 
 highest ca release . after 28 days , sealer 26 and white mta presented the 
 highest carelease . in all experimental periods , zoe had the lowest 
 ca release values . mean  standard deviation of calcium ( mg% ) released from the materials 
 studied after different periods of time ( a , b , c , d ) in each period , means values followed by different labels are 
 statistically different ( p<0.05 ) . the methodology we followed consists in filling standardized tubes with the materials to 
 be tested and immersing in distilled water . numerous authors have 
 utilized similar methodology , immersing the plastic tubes containing cements in 
 distilled , deionized , or milli - q water . ( 2003 ) used tubes measuring 10 mm in length and 1.5 mm in 
 internal diameter . ( 2005 ) evaluated ph and calcium release using mta and an experimental dental cement 
 placed in tubes measuring 10 mm in length and 1 mm in diameter . although several ch - based sealers are available in the market , the presence of ch in the 
 composition of an endodontic sealer does not assure release of calcium and 
 oh ions in the final product . after setting of the cement , the ions may 
 not be released , or the ch may be 
 inactivated by other components in the sealer . the endodontic materials sealer 26 and epiphany contain ch or calcium oxide in their 
 formulation . when the set material is 
 placed in a solution , it dissociates into oh and ca ions , 
 increasing both the ph and the calcium concentrations in the medium . regarding the ph of the cements evaluated , during the first 12 h , sealer 26 and this may be due to 
 the presence of 37% ch in the composition of sealer 26 , and due to its longer setting 
 time . epiphany cement , which contains calcium oxide , had 20% ch incorporated into its 
 formulation . ( 2000 ) , who observed higher ph values for sealer 26 in 
 the initial experimental periods , when using the material in the powder/ resin ratio 
 recommended for it use as a root canal sealer . mta had initial ph of 9.01 ; 3 h after 
 mixing its ph was 8.28 and remained constant thereafter . these results are in accordance 
 with those obtained by duarte , et al . ( 2007 ) described the 
 calcium phosphate phases produced after immersion of set portland cement in phosphate 
 buffered saline solution . the authors observed that the ph changes occurred in two 
 stages , with release of oh ions during the precipitation of calcium 
 phosphate . moreover , these authors concluded that the biological action of mta may be 
 partially attributed to the ability to induce mineralized tissue formation by the 
 components of portland cement . from 12 h through 14 days after mixing , epiphany cement with 20% and 10% ch and pure 
 epiphany showed the greatest levels of calcium ion release , which may be related to the 
 material s properties of water sorption and solubility . ( 2007 ) reported a higher degree of water 
 sorption and solubility for epiphany compared to ketac - endo , innoendo , endorez , kerr 
 ewt , ah plus , and guttaflow cements . these properties may have contributed to the high 
 values observed for ca release in the longer experimental periods . ( 2004 ) , suggested the 
 addition of ch to ah plus cement in order to decrease its flowability . in the present 
 study , addition of ch to epiphany promoted better consistency for its use in retrograde 
 fillings , accompanied by greater release of oh and ca ions . further studies are necessary for a more detailed evaluation of the properties of this 
 material , including its biological effects . based on the methodology used in this study , it may be concluded that sealer 26 , white 
 mta , epiphany , and epiphany with ch presented ca and oh ion 
 release .
objectivehydroxyl ( oh- ) and calcium ( ca++ ) ion release was evaluated 
 in six materials : g1 ) sealer 26 , g2 ) white mineral trioxide aggregate ( mta ) , g3 ) 
 epiphany , g4 ) epiphany + 10% calcium hydroxide ( ch ) , g5 ) epiphany + 20% ch , and 
 g6 ) zinc oxide and eugenol.material and methodsspecimens were placed in polyethylene tubes and immersed in distilled water . 
 after 
 3 , 6 , 12 , 24 , and 48 h , 7 , 14 , and 28 days , the water was assessed for ph with a 
 ph meter and for ca++ release by atomic absorption 
 spectrophotometry.resultsg1 , g2 , g4 , and g5 had the highest ph until 14 days ( p<0.05 ) . 
 g1 presented 
 the highest ca++ release until 6 h , and g4 and g5 , from 12 h through 14 
 days . 
 ca++ release was greater for g1 and g2 at 28 days . 
 g6 released 
 the least ca++.conclusionmta , sealer 26 , epiphany , and epiphany + ch release oh - and 
 ca++ ions . 
 epiphany + ch may be an alternative as retrofilling 
 material .