is by micromechanical retention followed by the acid etching procedure while adhesion to dentin has always been a subject of interest owing to its complex nature . over the past 45 years , dentin
bonding agents have evolved with variation in its chemistry , application , mechanism , technique , and effectiveness . in continuity for a better adhesion ,
introduced in late 2002 , the seventh generation dentin bonding agent combines etchant , primer , and adhesive in a single bottle .
the rationale behind these acidic primers is to superficially demineralize the dentin and simultaneously penetrate to the depth of demineralization that can be polymerized in situ . in the present study ,
adper easy one ( 3 m espe ) and xeno v ( dentsply ) , seventh generation adhesive systems were used . during the restorative procedure ,
the presence of moisture in the form of saliva , blood , and gingival fluid affects the quality of bond resulting in microleakage , recurrent caries , and postoperative sensitivity .
however , as rubberdam may not be possible in all the clinical cases , cotton rolls , when used during isolation , may result in some amount of contamination which may be undetected several times .
thus , the aim of this study is to compare the influence of salivary contamination on the dentin bond strength of two different seventh generation adhesive bonding systems .
sixty human extracted premolars without cracks , caries and restorations were selected for this study .
the teeth were cleaned of any residual tissue tags , rinsed under running water and stored in normal saline .
the cleaned teeth were embedded in aluminum molds with self - cure acrylic resin till the cervical region .
the occlusal surfaces of the teeth were reduced using high - speed handpiece with tapered diamond bur ( 856 - 018 ) under water - spray coolant to create a flat dentin surfaces at a depth of 1.5 mm from the cuspal tip .
group i ( n = 10 ) : application of adper easy one ( 3 m espe , bengaluru , india ) to dentin surface for 20 s followed by light curing for 20 s.group ii ( n = 10 ) : application of adper easy one ( 3 m espe ) for 20 s , saliva application for 10 s , air dried for 5 s followed by light curing for 20 s.group iii ( n = 10 ) : application of adper easy one ( 3 m espe ) for 20 s , saliva application for 10 s , air dried for 5 s and reapplication of adper easy one ( 3 m espe ) that was light cured for 20 s.group iv ( n = 10 ) : application of xeno v ( dentsply , mumbai , india ) for 20 s followed by light curing for 20 s.group v ( n = 10 ) : application of xeno v ( dentsply ) for 20 s , saliva application for 10 s , air dried for 5 s followed by light curing for 20 s.group vi ( n = 10 ) : application of xeno v ( dentsply ) for 20 s , saliva application for 10 s , air dried for 5 s and reapplication of xeno v ( dentsply ) that was light cured for 20 s. 
  group i ( n = 10 ) : application of adper easy one ( 3 m espe , bengaluru , india ) to dentin surface for 20 s followed by light curing for 20 s. group ii ( n = 10 ) : application of adper easy one ( 3 m espe ) for 20 s , saliva application for 10 s , air dried for 5 s followed by light curing for 20 s. group iii ( n = 10 ) : application of adper easy one ( 3 m espe ) for 20 s , saliva application for 10 s , air dried for 5 s and reapplication of adper easy one ( 3 m espe ) that was light cured for 20 s. group iv ( n = 10 ) : application of xeno v ( dentsply , mumbai , india ) for 20 s followed by light curing for 20 s. group v ( n = 10 ) : application of xeno v ( dentsply ) for 20 s , saliva application for 10 s , air dried for 5 s followed by light curing for 20 s. group vi ( n = 10 ) : application of xeno v ( dentsply ) for 20 s , saliva application for 10 s , air dried for 5 s and reapplication of xeno v ( dentsply ) that was light cured for 20 s. following the bonding procedure , plastic tubes of 3 mm diameter and 2 mm height were placed on each specimen and resin composite z350 ( 3 m espe ) was packed , and light cured .
plastic tubes were then removed and placed in 37c distilled water for 24 h to simulate the oral environment . then the specimens were transferred to the universal testing machine and subjected to shear bond strength ( sbs ) analysis at a crosshead speed of 1 mm / min .
the data obtained from the present study was subjected to statistical analysis by using one - way analysis of variance [ table 1 ] , multiple tukey 's test and student 's unpaired t - test for intergroup comparison using software spss 16 # ( spss inc . ,
comparison of sbs by anova test using tukey 's multiple test the sbs of groups i , ii and iii wherein adper easy one was used and groups iv , v , and vi wherein xeno v ( dentsply ) was used were compared showed statistical significant difference amongst the groups [ table 2 ] .
similarly , intergroup comparison was done using unpaired t - test where statistically significant difference was seen between groups i and iv and group iii and vi . between group ii and group v nonsignificant difference
tukey 's multiple comparison test for group i , ii and iii in which adper easy one was used and for group iv , v and vi in which xeno v was used comparison of shear bond strength by using adper easy one and xeno v ( intergroup comparison : student 's unpaired t - test )
adhesive dentistry has fundamentally altered and literally transformed our field toward significantly less intrusive , more esthetic , and lifelong dental restorations . elementary mechanism of bonding to tooth structure involves the flow of resin monomers into the microporosities and form an effective micromechanical bond .
adhesive dentistry demands for effective isolation of the operative field . usually , rubber dam isolation is the standard method which provide strict moisture control .
some clinical situations restrict the use of rubber dam . in such cases , cotton rolls and saliva ejector
however , this method of isolation may result in moisture contamination like saliva , gingival fluid etc .
contamination influences the nature of bond and results in microleakage , secondary caires , and postoperative sensitivity . considering all this
, there is absolute need to test the effect of salivary contamination on bond strength of the adhesive .
the present study chooses natural saliva as the contaminant as artificial saliva may confound the results .
salivary contamination seals irregularities and leads to an insufficient flow of resin into the tooth surface resulting in bond failure .
several salivary contamination studies concluded that the existence of glycoproteins in the saliva get adsorbed onto the adhesive layer , thereby intercepting adequate co - polymerization . on reapplication of adhesive , the values obtained
sbs of adper easy one and xeno v adhesive systems were compared and observed that the salivary contamination significantly affected the sbs of both the seventh generation dentin bonding agents which is 2-hydroxyethyl methacryate ( hema ) based and hema free . however , the reapplication of the adhesive system after the salivary contamination improved the bond strength values as compared to the salivary contaminated group where reapplication of adhesive was not done .
moreover , it was observed that adper easy one showed better results as compared with xeno v dentin bonding agents .
it was observed that group i ( adper easy one ) gave highest mean sbs to dentin compared to all other groups followed by group iv ( xeno v ) , whereas group v gave lowest mean sbs value followed by group ii which was contaminated by the saliva .
seventh generation adper easy one adhesive contains hema , bis - gma , methacrylated phosphoric esters , 1,6 hexanediol dimethacrylate , methacrylate functionalized polyalkenoic acid , ethanol , water , initiators based on camphorquinone and stabilizers .
the xeno v adhesive system contains bifunctional acrylic resin with amide function , acryloylamino alkylsulfonic acid , inverse functionalized phosphoric acid ester , acrylic acid , camphorquinone ( coinitiator ) , butylated benzenediol , water and tert - butanol .
adper easy one and xeno v both act as mild self - etch adhesives which have unique property that all hydroxyapatite are not removed from the interconnected area , and much of the calcium is obtainable for supplementary chemical action with definite adhesive monomers .
the conservation of hydroxyapatite inside the submicron hybrid layer possibly serve as a receptor for further chemical bonding .
self - etching adhesives growingly become more favored due to their easily and rapid application procedure .
elimination of different steps in application procedure also produced fewer errors during application of the adhesive .
even the presence of hema in adper easy one , which is found to be hydrophilic in nature causes the proper wetting of the surface and enhance the bond strength .
if the collapse of collagen fibrils occurs during the bonding procedure , hema rich adhesive causes the softening of the collagen network and allow it to re - expand .
from the data obtained , it can be concluded as : 
 salivary contamination significantly affects the sbs of both adper easy one and xeno v.hema based adhesives have higher bond strength than the hema free adhesives.reapplication of adhesive system after the salivary contamination resulted in improved bond strength . 
 
salivary contamination significantly affects the sbs of both adper easy one and xeno v. hema based adhesives have higher bond strength than the hema free adhesives .
 aim : to investigate the effect of salivary contamination on the bond strength of two different seventh generation adhesive systems.materials and methods : sixty caries - free human premolars with flat dentin surfaces were randomly divided into six groups of 10 teeth each and bonding was done using seventh - generation bonding agents adper easy one ( 3 m espe ) and xeno v ( dentsply ) . following the bonding procedure , resin composite was bonded to the surfaces using a plastic mould . the prepared specimen with composite cylinders attached 
 were placed in 37c distilled water for 24 h and then subjected to shear bond strength ( sbs ) with 0 h universal testing machine and the data were subjected to one - way analysis of variance and unpaired t-test.results:statistical significant difference between the groups i , ii and iii in which adper easy one was used and similarly for groups iv , v , and vi in which xeno v was used . when an intergroup comparison was made using unpaired t - test group ii and group v showed the nonsignificant difference.conclusion:salivary contamination significantly affects the sbs of both the seventh generation dentin bonding agents . 
 however , 2-hydroxyethyl methacryate based adhesive has higher bond strength . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSION
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