maintaining the deciduous teeth in the dental arch till it exfoliates is pivotal in maintaining the integrity of the arch , establishing occlusion and function of the permanent dentition .
the main reasons for premature loss of primary teeth are dental trauma or dental caries .
every effort should be taken to preserve the vitality of the pulp as it leads to more favorable treatment outcomes .
indirect pulp treatment ( ipt ) is one of the most preferred vital pulp treatment modality in restorative dentistry today which may be attributed to the introduction of new biocompatible materials and a better understanding of pulp biology .
dorfman et al . in 1943 stated that decalcification of dentin precedes bacterial invasion within the dentin . removing the outer layer of carious dentin , that contain the majority of the microorganisms , reducing the continued demineralization of the deeper dentin layers from bacterial toxins , and sealing the lesion to allow the pulp to generate reparative
ca(oh)2 has been the material of choice for indirect pulp capping for over 200 years .
it served as the gold standard to which newly introduced pulp capping materials were compared .
the introduction of newer materials with bioactive properties such as mineral trioxide aggregate ( mta ) , light cured calcium silicate ( theracal lc ) , biodentin helped surpass the demerits of ca(oh)2 such as nonadherence to dentin , dissolution over time , and tunnel defects and ensured increased success rate for ipt procedure .
the major constituents of this material are dicalcium silicate , tricalcium silicate , tricalcium aluminate , gypsum , and tetracalcium aluminoferrite .
it has good reparative dentin - forming ability as confirmed by many in vivo studies using this material in vital pulp therapies .
the drawbacks of mta include longer setting time , difficult handling characteristics , high cost , and solubility demonstrating 24% loss after 78 days of storage in water .
theracal lc is a new class of materials called resin modified calcium silicates that have been reported to stimulate apatite formation and the formation of reparative dentin .
theracal contains approximately 45% wt mineral material ( type iii portland cement ) , 10% wt radiopaque component , 5% wt hydrophilic thickening agent ( fumed silica ) , and approximately 45% hydrophobic resin .
both mta and theracal have been proved to have the ability to induce reparative dentin formation . in a literature search , no studies were found evaluating ipt using mta and theracal in primary molars .
hence , the present study was done to evaluate the reparative dentin - forming ability of mta and theracal in ipt in primary molars .
the study design was a clinical trial in a sample of 43 primary molars in 21 patients divided into two groups by simple random sampling method .
forty - three healthy primary molars in 21 patients aged between 4 and 7 years with deep carious lesion on either occlusal or proximal surface with no history of spontaneous pain and with a remaining dentin thickness ( rdt ) of more than 0.25 mm in the bitewing radiograph , as measured using coreldraw x3 software ( corel corporation , ottawa , ontario , canada ) ( mean rdt in mta group 
periodontally sound teeth with large carious lesion with no history of spontaneous pain , with more than 2/3 of the root present , with no periapical changes and absence of sinus tract , were selected for the study .
teeth with definite pulpal involvement , discoloration , mobility and radiographically signs of internal resorption , pulpal calcification , periapical or furcation involvement were excluded .
the teeth with deep carious lesion with no history of spontaneous pain were subjected to routine standardized periapical and posterior bitewing radiograph to ascertain the inclusion criteria .
after administration of topical anesthetic , the tooth to be treated was isolated using rubber dam .
care was taken to remove caries completely from the lateral walls of the cavity and cavosurface margin .
soft caries at the pulpal floor of the cavity was removed preserving the affected dentin as identified by visual and tactile method .
following caries removal , the cavity was flushed with saline for 10 s and dried with cotton pellets . in patients belonging to group i ,
mta powder was mixed with sterile water for 30 s so as to get a sandy consistency and carried with a ball ended condenser tip and applied by light pressure with moist cotton pellet .
the cotton pellet was placed in the cavity , and temporary restoration with znoe was done .
a base with resin - modified glass ionomer cement ( rmgic ) followed by composite restoration was given post 45 min once the cotton pellet and temporary was removed . in patients belonging to group ii
, theracal lc was applied directly to the dentin surface using the dispensing syringe and light cured for 20 s , followed by rmgic base and composite restoration .
a baseline radiograph was made after the restoration using an extension cone paralleling ( xcp ) film holder .
subsequently , at 3 and 6 months , the teeth were clinically examined and radiographically evaluated .
all the radiographs were standardized using xcp technique and scanned and transferred to the computer for digital analysis .
dentin thickness was measured at the baseline , 3 and 6 months using coreldraw x3 software [ figures 14 ] by an independent examiner who was blinded to the study .
the digitalized images were overlapped using the software keeping cementoenamel junction and the highest point in the floor of pulp chamber as reference points , and increment in dentin thickness was measured .
mineral trioxide aggregate group measurement of reparative dentin formation  mineral trioxide aggregate group [ magnified ] measurement of reparative dentin formation 
theracal group [ magnified ] intragroup comparison of dentin increment in both the test groups was done between baseline value and baseline to 3 months value ( a ) , baseline value and 36 months value ( b ) , baseline to 3 months value and 36 months value ( c ) , and baseline value and baseline to 6 months value ( d ) .
criteria for clinical evaluation included the absence of spontaneous pain , sensitivity to pressure , fistula , edema , and abnormal mobility .
treatment was considered to be successful when the pulp remained vital with no signs of spontaneous pain and no radiographic evidence of pathologic change at the end of study period .
statistical analysis was performed using spss software version 20 ( ibm corporation , armonk , new york , united states ) .
intragroup and intergroup comparison for an increase in dentin thickness was carried out using independent t - test .
forty - three healthy primary molars in 21 patients aged between 4 and 7 years with deep carious lesion on either occlusal or proximal surface with no history of spontaneous pain and with a remaining dentin thickness ( rdt ) of more than 0.25 mm in the bitewing radiograph , as measured using coreldraw x3 software ( corel corporation , ottawa , ontario , canada ) ( mean rdt in mta group 
periodontally sound teeth with large carious lesion with no history of spontaneous pain , with more than 2/3 of the root present , with no periapical changes and absence of sinus tract , were selected for the study .
teeth with definite pulpal involvement , discoloration , mobility and radiographically signs of internal resorption , pulpal calcification , periapical or furcation involvement were excluded .
the teeth with deep carious lesion with no history of spontaneous pain were subjected to routine standardized periapical and posterior bitewing radiograph to ascertain the inclusion criteria .
after administration of topical anesthetic , the tooth to be treated was isolated using rubber dam .
care was taken to remove caries completely from the lateral walls of the cavity and cavosurface margin .
soft caries at the pulpal floor of the cavity was removed preserving the affected dentin as identified by visual and tactile method . following caries removal ,
the cavity was flushed with saline for 10 s and dried with cotton pellets . in patients belonging to group i ,
mta powder was mixed with sterile water for 30 s so as to get a sandy consistency and carried with a ball ended condenser tip and applied by light pressure with moist cotton pellet .
the cotton pellet was placed in the cavity , and temporary restoration with znoe was done .
a base with resin - modified glass ionomer cement ( rmgic ) followed by composite restoration was given post 45 min once the cotton pellet and temporary was removed . in patients belonging to group ii
, theracal lc was applied directly to the dentin surface using the dispensing syringe and light cured for 20 s , followed by rmgic base and composite restoration .
a baseline radiograph was made after the restoration using an extension cone paralleling ( xcp ) film holder .
subsequently , at 3 and 6 months , the teeth were clinically examined and radiographically evaluated .
all the radiographs were standardized using xcp technique and scanned and transferred to the computer for digital analysis .
dentin thickness was measured at the baseline , 3 and 6 months using coreldraw x3 software [ figures 14 ] by an independent examiner who was blinded to the study .
the digitalized images were overlapped using the software keeping cementoenamel junction and the highest point in the floor of pulp chamber as reference points , and increment in dentin thickness was measured .
mineral trioxide aggregate group measurement of reparative dentin formation  mineral trioxide aggregate group [ magnified ] measurement of reparative dentin formation 
theracal group [ magnified ] intragroup comparison of dentin increment in both the test groups was done between baseline value and baseline to 3 months value ( a ) , baseline value and 36 months value ( b ) , baseline to 3 months value and 36 months value ( c ) , and baseline value and baseline to 6 months value ( d ) .
criteria for clinical evaluation included the absence of spontaneous pain , sensitivity to pressure , fistula , edema , and abnormal mobility .
treatment was considered to be successful when the pulp remained vital with no signs of spontaneous pain and no radiographic evidence of pathologic change at the end of study period .
statistical analysis was performed using spss software version 20 ( ibm corporation , armonk , new york , united states ) .
intragroup and intergroup comparison for an increase in dentin thickness was carried out using independent t - test .
of a total of 22 specimens included in the mta group , four specimens were excluded due to loss of follow - up .
deposition of tertiary dentin in mta group at the end of 3 months varied between 0.073 mm and 0.119 mm . from 36 months , it varied between 0.041 mm and 0.073 mm .
the mean increment in dentin thickness in first 3 months was 0.095  0.014 mm and from 36 months was 0.056  0.009 mm .
the average increase in dentin thickness in a total 6 months was 0.151  0.022 mm .
intragroup comparison of dentin increment in mta group showed a statistically significant increase in dentin thickness when the baseline value was compared with baseline to 3 months value with a p < 0.001 ( a ) [ table 1 ] .
statistically significant increase in dentin thickness was noted when baseline value was compared with that of 36 months ( b ) [ table 1 ] .
comparison of baseline to 3 months value with 36 months value also gave an increase in dentin thickness with a p < 0.001 which was statistically significant ( c ) [ table 1 ] .
similarly when baseline value was compared with total 6 months value , a statistically significant increase in dentin thickness was found with a p < 0.001 ( d ) [ table 1 ] .
intragroup comparison - mineral trioxide aggregate group three of the total 21 specimens included in the theracal group were excluded ; one due to a loss of follow - up and two due to dislodged restoration .
deposition of tertiary dentin in the theracal group at the end of 3 months varied between 0.088 mm and 0.115 mm ; from 3 to 6 months it varied from 0.046 mm to 0.059 mm .
the mean increase in dentin thickness in the first 3 months was 0.101 mm  0.008 mm and from 3 months to 6 months was 0.053 mm  0.004 mm .
the average increase in dentin thickness in total 6 months was 0.154 mm  0.012 mm .
intragroup comparison of dentin increment in theracal group also showed a statistically significant increase in dentin thickness when the baseline value was compared with a baseline to 3 months ( a ) [ table 2 ] and also while comparing baseline value with that of 36 months ( b ) [ table 2 ] .
comparison of baseline to 3 months value with 36 months value gave a statistically significant result with p < 0.001 ( c ) [ table 2 ] .
statistically significant result was obtained when the baseline value was compared with total 6 months value ( d ) [ table 2 ] .
intragroup comparison - theracal group intergroup comparison between mta and theracal using independent t - test was done between baseline to 3 months , 36 months , and total 6 months .
intergroup analysis of dentin increment in the first 3 months and next 3 months between mta and theracal were not significant yielding a p = 0.091 and 0.149 respectively .
increase in dentin increment in a total of 6 months was also compared between both the materials ( p = 0.611 ) [ table 3 ] .
these results showed that even though there is increase in dentin thickness within each group , there is no significant difference in dentin increment when comparing both groups .
intergroup comparison comparing the difference in dentin increment in both groups showed that dentin increment in first 3 months was statistically significant when compared to dentin increment in 36 months ( p < 0.001 ) [ table 4 ] .
intergroup comparison - mineral trioxide aggregate and theracal intergroup comparison ( difference ) between mineral trioxide aggregate and theracal
however , many studies have proved that the success of ipt was more compared to that of pulpotomy . a retrospective study by farooq et al
. showed normal exfoliation pattern for teeth treated with ipt compared to teeth treated by pulpotomy procedure , which showed early exfoliation .
careful diagnosis of the pulpal status is essential for the success of any conservative pulp treatment .
the samples for this study were selected based on the clinical and radiographic criteria for ipt .
correlated clinical and radiographic evaluation of pulp status with histologic findings and found that findings using defined criteria for clinical and histological classification of pulp conditions revealed a good agreement especially for cases with no pulpal disease or reversible disease .
the mean rdt determined from the bitewing radiographs in the mta group was 0.515  0.182 mm and that of the theracal group was 0.522  0.179 mm .
as reported by murray and smith preparation of deep cavities with an rdt of 0.250.004 mm injures underlying odontoblasts , preventing the secretion of reactionary dentin beneath the cavity preparation .
assessment of dentin thickness was done at the baseline , at the end of 3 months and 6 months in the digitalized radiographs keeping cement - enamel junction and highest point on the floor of the pulp chamber as reference points . in an in vitro study in extracted teeth ,
krasner and rankow proposed the presence of identifiable reference points for locating the floor of pulp chamber .
the authors demonstrated that the floor of the pulp chamber is always located in the center of the tooth at the level of the cement - enamel junction and the cement - enamel junction is the most consistent , repeatable landmark for locating the position of the pulp chamber .
large round bur in a slow speed handpiece was used for the caries removal in this study .
falster in an in vivo study comparing the pulp protecting ability of calcium hydroxide and adhesive resin demonstrated that the use of large , round carbide burs allow for better control of the  partial caries removal step  at the site of potential pulp exposure when compared to the use of spoon excavator . with spoon excavators ,
removal of affected dentin from deeper layers may cause accidental pulp exposure more commonly than with round burs at low speed .
mta is available as grey mta ( gmta ) and white mta ( wmta ) .
the occurrence of discoloration and longer setting time in association with gmta led to the introduction of wmta with the elimination of iron , preventing alumina - ferrite formation which was responsible for the discoloration .
smaller particle size of wmta provides greater specific surface area which increases wetting volume , water - binding capacity and hydration rate .
no significant difference between gmta and wmta in terms of calcified bridge thickness and pulp inflammatory response to the capping materials was observed in the study by eskandarizadeh et al .
owing to its superior properties , wmta was used as one of the test material in this study .
the drawbacks of mta include longer setting time , difficult handling characteristics , high cost , and solubility demonstrating 24% loss after 78 days of storage in water .
theracal has high calcium releasing ability , lower solubility , and comparable shear bond strength when compared with mta .
studied the sealing ability of theracal , biodentin and mta using confocal laser scanning microscopy and found out that theracal exhibits better sealing ability as a pulp capping agent than mta and biodentin . in the histologic study of direct pulp capping with theracal , cannon et al
proved that theracal demonstrated a complete hard tissue formation , adhesiveness to moist substrate and more positive response to the pulp exposure and bacterial contamination .
theracal has higher bond strength than mta in alkaline environment of the dentin as corroborated by the in vitro study comparing the push - out bond strength of biodentin , glass ionomer cement ( gic ) , mta and theracal .
there was no statistical difference in dentin deposition at the end of the first 3 months , second 3 months , and total 6 months between mta and theracal .
this may be attributed to the fact that theracal is chemically similar to mta formulation with the addition of hydrophobic resin . between the groups ,
the dentin increment in first 3 months in theracal group was higher when compared to that of the mta group , though not statistically significant .
in theracal , there is increased calcium ion release at the initial period of 28 days , which decreases later .
the alkaline ph of theracal decreases from 10 - 11 to 8 - 8.5 in 714 days creating a favorable environment for pulp cell viability and metabolic activity with the formation of reparative tertiary dentin
. the average dentin increment in the first 3 months in both groups was significantly higher when compared to second 3 months which may be attributed to decrease in calcium release by both materials over time as explained by in vitro study by gandolfi et al .
present study showed high tertiary dentin formation by both the test materials owing to the fact that both materials release calcium ions in sufficient quantities to promote reparative dentin formation .
the average reparative dentin formation in this study after mta placement in 6 months was found to be 0.151  0.022 mm .
this result is in agreement with the study done by george et al . comparing the reparative dentin formation between mta and ca(oh)2 in which the dentin increment in 6 months in the mta group was found to be 0.143  0.045 mm .
the mean reparative dentin formation in the theracal group in 6 months was found to be 0.154 mm  0.012 mm .
the 83% success rate of ipt restored with stainless steel crowns was not statistically different from the 87% success in teeth restored with intracoronal restoration . in vitro study done by kasraei et al .
shikha et al . in a comparative study of shear bond strength between rmgic and conditioned and unconditioned mta surface concluded that rmgic can be applied as a base over mta when used in direct pulp treatment or furcal repair .
gic placed over 45 min as opposed to 72 h old mta , showed no effect on crazing , setting time or shear bond strength with a noticeable formation of calcium salts at the interface .
rmgic also has a better bonding to composite resin than the conventional gic due to the similar chemistry between rmgic and composite resin .
both are cured by a free radical initiator system which provides a potential for chemical bonding between these two materials . as suggested in the above studies ,
rmgic was placed over both mta and theracal before placing a composite restoration to obtain an optimum marginal seal . in the present study , failure due to dislodged restorations
tooth position in the arch , the restoration size with a large configuration factor , and self - etching primer bonded to enamel , high caries activity challenge may possibly explain the failure rate of occlusal restorations of second primary molars . based on the results of the present study , both mta and theracal showed statistically significant tertiary dentin deposition .
further long - term studies with larger sample size and histologic evaluation are required to confirm these results .
more researches directed toward the development of better economical and biocompatible materials which do not affect the pulp vitality and normal resorption are needed for providing less invasive , quality dental treatment for the pediatric patients .
based on the results of this short - term clinical and radiographic study , the following conclusions were drawn : 
 clinically and radiographically , both mta and theracal are good ipt medicaments with significant reparative dentin formationradiographically , both mta and theracal showed increased dentin deposition in first 3 months when compared to the second 3 months . 
 
clinically and radiographically , both mta and theracal are good ipt medicaments with significant reparative dentin formation radiographically , both mta and theracal showed increased dentin deposition in first 3 months when compared to the second 3 months . due to the ease of application , comparable tertiary dentin formation , better sealing ability and the convenience to provide the final restoration in a single appointment , theracal may be recommended as an alternative to mta in pediatric restorative dentistry .
 aim : to clinically and radiographically evaluate the reparative dentin formation in indirect pulp treatment ( ipt ) using mineral trioxide aggregate ( mta ) and light cured calcium silicate ( theracal ) in primary molars over a period of 6 months.materials and methods : a clinical trial on ipt on 43 primary molars in 21 patients between the age of 47 years , divided into two groups : 22 teeth in mta group and 21 in theracal group . 
 measurement of the variation in dentin thickness was done on the digitalized radiograph at baseline , 3 months and 6 months using coreldraw x3 software.results:statistical analysis using an independent t - test for intragroup and intergroup comparison showed a significant increase in dentin thickness in both the mta and theracal group ( intragroup comparison [ p < 0.05 ] ) 
 . however , intergroup comparison between mta and theracal showed no statistical difference in reparative dentin formation ( p > 0.05).conclusion : clinically and radiographically , both mta and theracal are good ipt materials . the better handling characteristics and comparable reparative dentin - forming ability of theracal make this material an alternative to mta in pediatric restorative procedures . 
Introduction
Materials and Methods
Selection criteria
Sample preparation and experimentation
Results
Discussion
Conclusion
Financial support and sponsorship
Conflicts of interest