title: Shear bond strength of a new fluoride-releasing orthodontic adhesive. Effect of changing a test parameter on the shear bond strength of orthodontic brackets. Can previously bleached teeth be bonded safely? Bond strength comparison of moisture-insensitive primers. Clinical trials with crystal growth conditioning as an alternative to acid-etch enamel pretreatment. Effect of self-etching primers on bond strength--are they reliable? The influence of orthodontic bracket base design on shear bond strength. Comparison of bond strength between orthodontic brackets bonded with halogen and plasma arc curing lights: an in-vitro and in-vivo study. Shear bond strength of orthodontic brackets cemented with a zinc oxide-polyvinyl cement. Clinical performance of orthodontic brackets and adhesive systems: a randomized clinical trial. Shear bond strength comparison between two orthodontic adhesives and self-ligating and conventional brackets. A new one-step dental flowable composite for orthodontic use: an in vitro bond strength study. New protective polish effects on shear bond strength of brackets. Influence of force location in orthodontic shear bond strength testing. Influence of cross-head speed in orthodontic bond strength testing. A comparative in vitro study of the strength of directly bonded brackets using different curing techniques.
abstract: This study evaluated the shear bond strength of stainless steel brackets bonded to enamel with a new fluoride-releasing orthodontic adhesive system . A total of 140 extracted human bicuspids were r and omly divided into four groups . Group I ( Transbond XT ) was a control group in which enamel was etched with phosphoric acid . For the remaining groups , enamel was conditioned with a self-etching primer ( SEP ) : Group II ( Transbond Plus ) , Group III ( BeautyOrtho Bond ) , and Group IV ( BeautyOrtho Bond + Salivatect ) . Stainless steel brackets were bonded to all tooth sample s. After which , the sample s were stored , thermocycled , tested , and statistically analyzed . Besides bond strength evaluation , the adhesive remnant index ( ARI ) was also evaluated . The shear bond strengths of Groups II , III , and IV were significantly lower than Group I , and Group II was significantly greater than that of Group III . Concerning ARI scores , no significant differences were found between the groups . Further , no enamel fracture was observed during shear bond test with the new SEP . In conclusion , when enamel was conditioned with the new SEP , the mean values of shear bond strength yielded were lower than when it was etched with 37 % phosphoric acid . Nonetheless , these mean values were higher than the average suggested by Reynolds as optimum for clinical treatment The purpose of this study was to determine the effect of changing the crosshead speed of the testing machine on the shear bond strength of orthodontic brackets to enamel while st and ardizing all the other variables . Forty freshly extracted human molars were bonded using the Transbond XT adhesive system ( 3 M Unitek , Monrovia , Calif ) . The teeth were r and omly divided into two groups . In group I , the shear bond strength was measured at a crosshead speed of 5.0 mm/min , and in group II the shear bond strength was measured at a crosshead speed of 0.5 mm/ min . Within half an hour from the initial bonding of each tooth , an occlusogingival load was applied to the bracket , producing a shear force at the bracket-tooth interface . This was accomplished by using the flattened end of a steel rod attached to the crosshead of a Universal Test Machine ( Zwick GmbH & Co , Ulm , Germany ) . The t-test results ( t = 2.71 ) indicated that there was a significant difference ( P = .014 ) in the shear bond strengths between the group tested at a crosshead speed of 5.0 mm/min and the group tested at a crosshead speed of 0.5 mm/min . The mean shear bond strengths for the two groups were 7.0 + /- 4.6 MPa and 12.2 + /- 4.0 MPa , respectively . These findings indicated that it is important to identify the parameters included in shear bond testing in order to enable meaningful comparisons of the performance of different material The purpose of our study was to determine the effect of a 35 % hydrogen peroxide bleaching agent on the shear bond strength of metallic orthodontic brackets . Sixty premolars were r and omly divided into 3 groups of 20 each . Teeth in group A were etched with 37 % phosphoric acid before bonding metallic premolar brackets . Teeth in the other 2 groups were bleached with a 35 % hydrogen peroxide in-office bleaching agent according to the manufacturer 's recommendations . Twenty bleached teeth ( group B ) were bonded immediately , and the other 20 ( group C ) were stored in artificial saliva for 30 days before bonding . Shear bond strength of these brackets was measured on a universal testing machine and recorded in MPa . Adhesive remnant index ( ARI ) scores were determined after the brackets failed . Data were analyzed with analysis of variance ( ANOVA ) and chi-square tests . The shear bond strength values of groups A , B , and C were 12.9 + /- 3.4 , 12.0 + /- 4.6 , and 14.8 + /- 4.0 MPa , respectively . Results of ANOVA showed no statistically significant differences in shear bond strengths between groups ( P > .05 ) . ARI scores were significantly different in all groups . The unbleached group 's failures were primarily at the bracket/adhesive interface , whereas the bleached groups either showed cohesive failures within the adhesive or failed at the adhesive/enamel interface . The results of this study suggest that office bleaching with hydrogen peroxide does not adversely affect the bond strengths of brackets bonded immediately after bleaching or 30 days after bleaching , even though bleaching can result in differences in the failure site The objective of this in vitro bonding study was to evaluate the effectiveness of 2 moisture-insensitive primers , Assure ( Reliance Orthodontic Products , Itasca , Ill ) and MIP ( 3 M Unitek , Monrovia , Calif ) compared with a control hydrophobic primer , Transbond XT ( 3 M Unitek ) . Six groups of 40 premolars were acid etched and bonded using metal orthodontic brackets with the following in vitro protocol s : ( 1 ) Transbond XT primer and adhesive applied to a noncontaminated surface ; ( 2 ) Assure primer applied after saliva contamination ; ( 3 ) MIP primer applied after saliva contamination ; ( 4 ) Assure primer reapplied after saliva contamination ; ( 5 ) MIP reapplied after saliva contamination ; and ( 6 ) Assure adhesive applied after saliva contamination of the primer . All bonded specimens were stored in deionized water at 37 degrees C for 30 days and thermocycled for 24 hours before debonding . Brackets were debonded using a shear-peel load on a testing machine , bond strength was measured in megapascals , and bond failure was analyzed by using the adhesive remnant index . In vitro shear-peel bond strengths were acceptable for all groups , and the bond strengths for Assure and MIP were not significantly affected by saliva contamination . The mean shear-peel bond strength of the control ( 14.82 MPa ) was significantly higher ( P < .001 ) than the contaminated groups with the exception of MIP group 5 ( 14.02 MPa ) . The values of the Assure primer and adhesive were less than the MIP primer and its respective adhesive ; however , the hydrophilic Assure adhesive resin applied to a saliva-contaminated surface had acceptable bond strength . Bond failure analysis ( adhesive remnant index ) mainly showed adhesive bond failures . An increased frequency of enamel fractures at debond was noted , with the control group ( 1 ) and the MIP groups ( 3 and 5 ) having 22.5 % , 12.5 % , and 15 % , respectively . The Assure groups had no enamel fractures It has been cl aim ed that different ion solutions containing sulfate induce crystal growth and might be a better alternative than conventional acid etching for enamel pretreatment in bracket bonding . It should thus combine optimal bond strength with easy and quick debonding . Two clinical experiments were performed to test this hypothesis . The first experiment dealt with the debonding procedure . Following conditioning with dilute sulfuric acid which contained sodium sulfate ( to be termed solution A ) on one side of the mouth and etching with 37 % phosphoric acid on the other , brackets were bonded on the maxillary and m and ibular incisors of twenty dental nurse students . Debracketing and a subsequent cleanup procedure were performed after 2 days . The mode of loosening was mainly between the enamel surface and adhesive on the crystal-growth-conditioned teeth and between the bracket mesh and adhesive on the teeth etched with phosphoric acid . This difference in mode of loosening was statistically significant ( P less than 0.001 ) . In the second experiment , which dealt with the clinical bond strength , 250 brackets were bonded in forty patients . One side served as a control and was conventionally acid etched . On the experimental side conditioning was done with solution A in thirty patients . In ten patients , 10 % phosphoric acid was added to the dilute sulfuric acid used ( to be termed solution B ) . Failure rates and modes of failure were recorded for a 6-month period . ( ABSTRACT TRUNCATED AT 250 WORDS Currently introduced self-etching primers combine conditioning and priming agents into a single product . The purpose of this study was to determine the effects of using three self-etching primers on the shear bond strength ( SBS ) of orthodontic brackets and on the bracket/adhesive failure mode . Brackets were bonded to extracted human teeth according to one of four protocol s. In the control group , teeth were etched with 37 % phosphoric acid . In the experimental groups , the enamel was conditioned with three different self-etching primers , Clearfil SE Bond ( CSE ) , Etch & Prime 3.0 ( EP3 ) , or Transbond Plus ( TBP ) , as suggested by the manufacturer . The brackets were then bonded with Transbond XT in all groups . The present in vitro findings indicate that conditioning with TBP before bonding orthodontic brackets to the enamel surface result ed in a significantly ( P < or = .001 ) higher SBS ( mean , 16.0 + /- 4.5 MPa ) than that found in CSE , EP3 , and the control ( acid-etched [ AE ] ) groups . CSE produced bond strength values ( mean 11.5 + /- 3.3 MPa ) that are statistically comparable to those produced by acid etching ( mean 13.1 + /- 3.1 MPa ) . The use of EP3 for enamel conditioning result ed in the lowest mean SBS value ( mean 9.9 + /- 4.0 MPa ) . A comparison of the adhesive remnant index scores indicated that there was more residual adhesive remaining on the teeth that were treated with conventional acid etching than in the CSE and EP3 groups . In the TBP group , the failure sites were similar to those of the AE group but different from those of the CSE group Many bracket base design s and adhesive material s are in clinical use today . Bases have evolved from perforated metal bases to the present foil mesh bases , and treatments range from none , to spraying metal alloy onto the base , to the most common treatment of microetching . The purpose of this study was to determine the effect of orthodontic bracket base design on mean shear bond strength 1 hour or 24 hours after bonding . For each time group , 12 specimens of 6 types of metal brackets were bonded to bovine incisors with Transbond XT ( 3 M Unitek , Monrovia , Calif ) light-cured composite resin . Brackets were debonded 1 hour or 24 hours later , and the shear bond strength was recorded . Six debonded brackets of each type from each time group were selected at r and om and s and blasted . All the teeth were cleaned , and half were rebonded with used brackets , and half were rebonded with new brackets . Bond strength was measured again , 1 hour or 24 hours later . Representative specimens were inspected under the scanning electron microscope . Bracket base design significantly affected mean shear bond strength . Speed ( 60-gauge , microetched foil-mesh base ; Strite Industries , Cambridge , Ontario , Canada ) had the highest bond strength at 1 hour ; followed by Time ( machined , integral , microetched base with mechanical undercuts ; American Orthodontics , Sheboygan , Wis ) ; American Master Series ( 80-gauge foil-mesh base ; American Orthodontics ) ; Ovation Roth ( 80-gauge layered onto 150-gauge , microetched foil-mesh base ; GAC , Central Islip , NY ) ; Orthos Optimesh XRT ( 100-gauge microetched foil-mesh base ; Ormco , Orange , Calif ) ; and , finally , the nickel-free brackets ( injection molded , 100-gauge , microetched , foil-mesh base ; World Class Technology , McMinnville , Ore ) . The 24-hour results were similar except that Time had the highest mean shear bond strength ( ANOVA , P < .05 ) . Chairside s and blasting significantly affected the 1-hour , but not the 24-hour , mean shear bond strengths ( ANOVA , P < .05 ) . S and blasting appears to be an effective method of cleaning bracket bases before rebonding INTRODUCTION This study assessed in-vitro shear bond strength and in-vivo survival rate of orthodontic brackets bonded with either a halogen  or a plasma arc light . METHODS Ninety extracted premolars were divided into 6 groups of 15 . Stainless steel brackets were bonded to the teeth by using either a halogen light with a 20-second curing time or a plasma arc light with a 2- , 6- , or 10-second curing time . Brackets were debonded either within 30 minutes of bonding or after thermocycling for 24 hours . Bond strengths were tested on a testing machine at a crosshead speed of 1 mm/minute . The bracket failure interface was measured with a modified adhesive remnant index score . Data were analyzed by using ANOVA and Tukey-Kramer multiple comparison tests . For the in-vivo study , a split-arch design was used to determine the bracket-failure rate and distribution in 25 patients . The patients were followed for a mean period of 1.1 years ( 386 days ) . Survival analysis was carried out to compare the failure rates of the 2 techniques . RESULTS No significant differences in bond strengths were found 30 minutes after bonding between the halogen light ( 13.6 + /- 3.8 MPa ) and the plasma arc light with 2- , 6- , or 10-second curing times ( 9.6 + /- 2.9 , 14.2 + /- 4.6 , 16.0 + /- 3.0 MPa , respectively ) . Similar bond strengths were also found between the halogen light with a 20-second ( 16.1 + /- 3.6 MPa ) curing time and plasma arc light with 6 seconds ( 18.2 + /- 4.6 MPa ) of curing time after 24 hours of thermocycling . For the in-vivo study , no significant difference was found in bracket failure rates between the 2 light sources ( 4.9 % in both groups ) . No significant differences were found between ARI scores for the halogen light and the plasma arc light at either 30 minutes or 24 hours after debonding . CONCLUSIONS These results indicate that the plasma arc light with a 6-second curing time can produce similar bond strength and bracket-failure rates as the halogen light that requires a longer curing time The purpose of this study was to compare the shear bond strengths and enamel surface structure after debonding a conventional metal bracket and a polycrystalline ceramic bracket bonded with a bipolar zinc oxide-polyvinyl cement ( F-21 ) or a light-cured resin cement ( Transbond ) .  Forty extracted human premolars were used . The buccal enamel surfaces were used , and the teeth r and omly divided into four groups of 10 teeth each : group 1 : conventional metal bracket ( Unitek ) bonded with Transbond ; group 2 : metal bracket bonded with F-21 ; group 3 : ceramic bracket ( Transcend 2000 ) bonded with Transbond ; and group 4 : ceramic bracket bonded with F-21 . The brackets were bonded to the etched enamel surfaces according to manufacturer 's instructions . All specimens were stored in distilled water for 24 hours and then thermocycled for 300 cycles between 5 degrees C and 55 degrees C. The specimens were mounted in dental stone and placed in the Instron at a crosshead speed of 0.5 mm/min with a knife-edged blade . Immediately after debonding , the enamel surface and bracket-enamel interface were evaluated visually and with a stereomicroscope . Representative sample s were then examined with the scanning electron microscope . The analysis of variance and Student-Newman-Keuls tests were performed . The results in megapascals were Group 1 : 19,6 ( + /- 9,6 ) ; group 2 : 14,3 ( + /- 4,6 ) ; group 3 : 28,8 ( + /- 12,6 ) ; and group 4 : 18,5 ( + /- 7,5 ) . Group 3 was statistically significantly different ( P < 0.008 ) from all other groups . Groups 1 , 2 , and 4 were not significantly different . ( ABSTRACT TRUNCATED AT 250 WORDS The aim of the study was to evaluate and compare the clinical performance of adhesive precoated brackets ( APC ) with that of two types of uncoated bracket bases , Straight-Wire and Dyna-Lock , bonded using two types of orthodontic adhesives , Transbond XT , and Right-On .  Forty consecutive orthodontic patients entered the trial and 607 brackets were bonded . The incidence and site of first time bond failures were recorded over a period of 1 year . The time required for bonding was also recorded . The overall bond failure rate was 6.6 per cent . There were no significant differences between the failure rates of the five groups , or between the upper and lower arch . However , significantly more brackets failed on the left side than on the right . Premolar brackets were lost most often , whilst incisor brackets failed least . No association was found between bond failure and time elapsed since bonding . Bonding time was least with Right-On adhesive . There were no significant differences between bonding times using APC or Transbond . Results of the present study conflict with those of a previous ex vivo study by the authors , using the same material s and bonding technique . Suggested reasons for this are discussed OBJECTIVE To evaluate and compare the shear bond strengths of two adhesives using two types of brackets : a conventional and a self-ligating bracket system . MATERIAL S AND METHODS Sixty extracted human premolars were collected . The premolars were r and omly divided into three groups of 20 teeth . All three groups were direct bonded . Groups 1 and 2 used light-cured adhesive and primer ( Transbond XT ) with a conventional ( Orthos ) and a self-ligating bracket ( Damon 2 ) , respectively . Group 3 used a light-cured primer ( Orthosolo ) and a light-cured adhesive ( Blūgloo ) with a self-ligating bracket ( Damon 2 ) . The specimens were stored in distilled water at 37 degrees C for 40 + /- 2 hours , after which they were debonded and inspected for Adhesive Remnant Index ( ARI ) scoring . RESULTS The mean shear bond strength was 15.2 MPa for group 1 , 23.2 MPa for group 2 , and 24.8 MPa for group 3 . A one-way analysis of variance and post hoc Tukey test showed significant differences in bond strength ( P < .001 ) between group 1 and groups 2 and 3 but no significant difference ( P > .05 ) between groups 2 and 3 . A Weibull analysis demonstrated that all three groups provided sufficient bond strength with over 90 % survival rate at normal masticatory and orthodontic force levels . A Kruskal-Wallis test showed no significant difference ( P > .05 ) in ARI scores among all three groups . CONCLUSIONS All three groups demonstrated clinical ly acceptable bond strength . The Damon 2 self-ligating bracket exhibited satisfactory in vitro bond strength with both adhesive systems used A new flowable composite , Denfil Flow , has shown an acceptable shear bond strength for bonding orthodontic brackets , when used with an intermediate , unfilled , low-viscosity resin . According to the manufacturer , it also shows a good viscosity for use with no preliminary adhesive . This could reduce the total time of bonding procedure while maintaining clinical ly useful bond strength . The aim of the current research was to assess this property . Eighty extracted human premolars were r and omly divided into four equal groups . Stainless steel brackets were bonded to etched enamel using ( 1 ) Denfil Flow , ( 2 ) a traditional flowable composite ( Dyract Flow ) , ( 3 ) Denfil Flow composite resin and an intermediate liquid resin , and ( 4 ) Transbond XT adhesive . Debonding was performed with a shearing force . The residual adhesive on the enamel surface was evaluated using the adhesive remnant index . The bond strength of Denfil Flow ( 34.8 MPa ) showed no significant difference with the other control groups and was clinical ly acceptable . Denfil Flow and Dyract Flow tended to display cohesive failure within the adhesive . Denfil Flow can be used without liquid resin to reduce the bonding procedure time while maintaining acceptable bond strength . Further studies are required to evaluate the enamel surface of the teeth after the same polishing procedure in the four groups One of the solutions for the problem of white spot lesions has been the application of a polymer coating to the labial enamel surface . The aim of this study is to find out whether the liquid polish BisCover affects the bond strength of brackets bonded with a light-cured system ( Transbond XT ) and a no-mix system ( Unite ) . St and ard stainless steel premolar brackets were bonded to 100 permanent human premolars r and omly divided into five equal groups . Two different enamel surface conditions were studied : dry and varnished with BisCover . For each enamel surface condition , two orthodontic adhesive systems were used : a light-cured system ( Transbond XT ) and a no-mix system ( Unite ) . All teeth were conditioned with 37 % phosphoric acid for 30 seconds , followed by thorough washing and drying . The teeth in groups 1 and 2 were bonded with Transbond XT and Unite , respectively . For groups 3 , 4 , and 5 , a thin layer of BisCover was applied to the etched enamel with a brush and light cured for 15 seconds . In group 3 , a thin layer of Transbond XT primer was applied , whereas in group 5 , no additional primer was used on BisCover . In groups 3 and 5 , the brackets were bonded with Transbond XT adhesive resin . Group 4 was bonded with no-mix Unite . Shear forces were applied to the sample s by a Zwick Universal test machine , and bond strengths measured in megapascals . The results revealed that shear bond strengths of the groups did not differ significantly from each other OBJECTIVE The purpose of the present study was to analyze the influence of debonding force location in shear bond strength testing of orthodontic brackets in vitro . METHODS Ninety extracted permanent bovine m and ibular incisors were r and omly divided into 3 groups of 30 specimens each . Teeth were bonded with stainless steel orthodontic brackets . Enamel surfaces were etched with 37 % phosphoric acid for 30s and bonded with a composite adhesive .  Debonding force measurements were performed with a universal testing machine . Location of the debonding force was : bracket base ( group A ) , ligature groove ( group B ) , occlusal bracket wings ( group C ) . RESULTS Mean shear bond strength measurements were as follows : 22.70(4.23)MPa ( group A ) , 11.52(2.74)MPa ( group B ) , 9.44(2.96)MPa ( group C ) . Analysis of variance indicated that there were significant differences in shear bond strength . Post-hoc Tukey tests showed that bond strength measurements of group A were significantly different from those of groups B and C. The adhesive remnant index also showed significant differences and ranged from a mean of 1.53 in group A to a mean of 2.10 in group C. SIGNIFICANCE Debonding force location had a significant influence on shear bond strength measurements and bond failure pattern , indicating that this parameter needs to be taken into consideration for inter study comparison of in vitro results OBJECTIVE The aim of this study was to investigate the influence of cross-head speed on debonding force of orthodontic brackets . METHODS One hundred and twenty extracted permanent bovine m and ibular incisors were r and omly divided into 4 groups of 30 specimens each . Teeth were bonded with stainless steel orthodontic brackets . Enamel surfaces were etched with 37 % phosphoric acid for 30 seconds and bonded with a composite adhesive .  Debonding force measurements were performed with a universal testing machine Zwicki Z 2.5 ( Zwick , Germany ) . Cross-head speeds of the four groups were : 0.1 mm s-1 ( group A ) , 0.5 mm s-1 ( group B ) , 1.0 mm s-1 ( group C ) , 5.0 mm s-1 ( group D ) . RESULTS Mean debonding force measurements were as follows : 215.35 ( 39.09 ) N ( group A ) , 231.79 ( 48.62 ) N ( group B ) , 236.64 ( 39.26 ) N ( group C ) , 224.95 ( 34.67 ) N ( group D ) . Analysis of variance indicated that there were no significant differences in debonding forces between the groups investigated . The adhesive remnant index showed a median value of 2.0 for all groups . SIGNIFICANCE Cross-head speed variation between 0.1 and 5 mm min-1 does not seem to influence debonding force measurements or failure mode of brackets bonded to enamel with a composite adhesive The aim of this study was to compare , by shear testing , the bond strengths after 1 and 24 hours of a light-cured resin ( Enlight ) and a light-cured glass ionomer cement GIC ( Fuji Ortho LC )  using various polymerization lamps ( halogen , high performance halogen , xenon , and diode ) for the direct bonding of brackets . The self-curing resin ( Concise ) was used as the control . The analysis was carried out using the SPSS program . For group comparison purpose s , the single factor variance analysis ( ANOVA ) and the post-hoc test ( Tukey 's HSD ) were used . The level of significance was established at P < 0.05 . When comparing two mean values the t-test for independent r and om sample s was employed . All polymerization lamps achieved the minimum bond strength of 5 - 8 MPa . With Enlight LV , bond strength was dependent on curing time ( the halogen lamp achieved the highest bond strength of 10.0 MPa , P < 0.001 , with a curing time of 40 seconds . The other lamps showed similar results ) and on the mode of cure ( the highest bond strength values were achieved by four-sided curing , P= 0.04 ) . Fuji Ortho LC , on the other h and , was independent of the duration of light curing and the type of lamp used . The bond strengths of the resin-modified glass ionomer cement ( RMGIC ) were similar to or somewhat higher than those achieved with light-cured composite resin ( P = 0.039 ) when lamps with short polymerization times were used , but were significantly lower ( P < 0.001 ) when compared with the self-curing composite adhesive . After 24 hours , the bond strengths of all adhesives showed a significant increase : Enlight 19 per cent , Fuji Ortho LC 6.6 per cent , Concise 16 per cent . Bond failure occurred for Enlight at the bracket-composite resin adhesive interface in 90 per cent and with Concise in 57 per cent . However , Fuji Ortho LC showed far more cohesive and mixed failures , indicating an improved bond between bracket and cement
target: Many studies on in-vitro orthodontic bond strength fail to report test conditions that could significantly affect their outcomes
background: INTRODUCTION The aims of this study were to systematic ally review the available literature regarding in-vitro orthodontic shear bond strength testing and to analyze the influence of test conditions on bond strength .