title: How Is the Enamel Affected by Different Orthodontic Bonding Agents and Polishing Techniques? Evaluation of enamel damages following orthodontic bracket debonding in fluorosed teeth bonded with adhesion promoter The Effects of Composite Resin Types and Debonding Pliers on the Amount of Adhesive Remnants and Enamel Damages: A Stereomicroscopic Evaluation Comparison of bond strength of three adhesives: composite resin, hybrid GIC, and glass-filled GIC. Enamel cracks and ceramic bracket failure during debonding in vitro. The effects of bracket removal on enamel. Effects on shear bond strength and the enamel surface with an enamel bonding agent.
abstract: Objectives : The objective of this study was to assess the effect of new bonding techniques on enamel surface . Material s and Methods : Sixty upper central incisors were r and omly divided into two equal groups . In the first group , metal brackets were bonded using TransbondXT and , in the second group , the same brackets were bonded with Maxcem Elite . The shear bond strength ( SBS ) of both agents to enamel was measured and the number and length of enamel cracks before bonding , after debonding and after polishing were compared . The number of visible cracks and the adhesive remnant index ( ARI ) scores in each group were also measured . Results : There were significantly more enamel cracks in the Transbond XT group after debonding and polishing compared to the Maxcem Elite group . There was no significant difference in the length of enamel cracks between the two groups ; but , in each group , a significant increase in the length of enamel cracks was noticeable after debonding . Polishing did not cause any statistically significant change in crack length . The SBS of Maxcem Elite was significantly lower than that of Transbond XT ( 95 % confidence interval ) . Conclusion : Maxcem Elite offers clinical ly acceptable bond strength and can thus be used as a routine adhesive for orthodontic purpose s since it is less likely to damage the enamel Objective : To evaluate shear bond strength ( SBS ) of the orthodontic brackets bonded to fluorosed and nonfluorosed teeth using Light Bond with and without adhesion promoters and compare their enamel damages following debonding . Material s and Methods : In this study , 30 fluorosed ( Thylstrup and Fejerskov Index = 4–5 ) and 30 nonfluorosed teeth were r and omly distributed between two subgroups according to the bonding material s : Group 1 , fluorosed teeth bonded with Light Bond ; Group 2 , fluorosed teeth bonded with adhesion promoters and Light Bond ; Group 3 , nonfluorosed teeth bonded with Light Bond ; Group 4 , nonfluorosed bonded with adhesion promoters and Light Bond . After bonding , the SBS of the brackets was tested with a universal testing machine . Stereomicroscopic evaluation was performed by unbiased stereology in all teeth to determine the amount of adhesive remnants and the number and length of enamel cracks before bonding and after debonding . The data were analyzed using two-way analysis of variance , Kruskal – Wallis , Wilcoxon Signed Rank , and Mann – Whitney test . Results : While fluorosis reduced the SBS of orthodontic bracket ( P = 0.017 ) , Enhance Locus Ceruleus LC significantly increased the SBS of the orthodontic bracket in fluorosed and nonfluorosed teeth ( P = 0.039 ) . Significant increasing in the number and length of enamel crack after debonding was found in all four groups . There were no significant differences in the length of enamel crack increased after debonding among four groups ( P = 0.768 ) while increasing in the number of enamel cracks after debonding was significantly different among the four groups ( P = 0.023 ) . Teeth in Group 2 showed the highest enamel damages among four groups following debonding . Conclusion : Adhesion promoters could improve the bond strength of orthodontic brackets , but conservative debonding methods for decreasing enamel damages would be necessary Background and aims . This in vitro study was design ed to evaluate the effect of composite resin types and orthodontic debonding pliers on the amount of adhesive remnants and enamel damages using a novel method of measurement . Material s and methods . 120 extracted human premolars were r and omly divided into four groups ( n = 30 ) . The st and ard edgewise metallic brackets were bonded to the teeth with light-cured composite resin “ Transbond XT ” in the first and second groups , and No-mix composite resin “ Unite ” in the third and fourth groups . Bracket debonding was carried out with Lift Off Debonding Instrument “ LODI ” ( 3 M Unitek ) in the first and third groups , and with Bracket Removing Pliers ( Dentaurum ) in the second and forth groups . yStereomicroscopic evaluation was performed by unbiased sterelogy . All teeth were evaluated for the amount of adhesive remnants and the number and length of enamel cracks . The obtained data on each step was analyzed by two-way ANOVA , chi-square , Wilcoxon , and Kruskal-Wallis . Results . Teeth in group 4 had the lowest adhesive remnants on the enamel surface ( p < 0.01 ) ; and the highest increase in the number of enamel cracks ( p < 0.01 ) among the groups . In addition , groups bonded with Unite showed the highest increase in the length of enamel cracks . Conclusion . Dentaurum debonding pliers with sheer – peel force , when used with the Unite adhesive ( group 4 ) , decreased the amount of adhesive remnants on the enamel surface while it increased enamel damages The objective of this study was to compare 3  orthodontic adhesives  in the areas of shear-peel bond strength , location of adhesive failure , and extent of enamel cracking before bonding and after debonding of orthodontic brackets . The adhesives included a composite resin control ( Transbond XT ; 3M/Unitek , St Paul , Minn ) , a resin-modified glass ionomer cement ( Fuji Ortho LC ; GC America Corp , Alsip , Ill ) , and a polyacid-modified composite resin under dry and saliva-contaminated conditions ( Assure ; Reliance Orthodontic Products Inc , Itasca , Ill ) . Metal brackets were bonded to the buccal surfaces of 160 ( 4 groups of 40 ) human premolars . The bonded teeth were stored in deionized water at 37 degrees C for 30 days and thermocycled for 24 hours before debonding with a Universal Instron ( Instron Corp , Canton , Mass ) testing machine . The extent of cracking in the buccal surfaces was evaluated under 16x magnification before bonding and after debonding . Although the bond strength of the composite resin control ( 20.19 MPa ) was significantly greater ( P < .05 ) than that of the adhesives in the other groups , clinical ly acceptable shear-peel bond strengths were found for all adhesives ( Fuji Ortho LC = 13.57 MPa , Assure-dry = 10.74 MPa , Assure-wet = 10.99 MPa ) . The bond strength for the Assure adhesive was not significantly affected by saliva contamination . The sample of extracted premolars used in this study displayed a greater frequency of buccal surface enamel cracking ( 46.7 % ) than that reported in the literature for in vivo premolars ( 7.8%-10.2 % ) , which was possibly due to the extraction process . The frequency of enamel cracking in a subset of this sample ( n = 34 ) increased from 46.4 % at prebonding to 62.4 % at postdebonding as a result of the forces of debonding OBJECTIVE To test the null hypothesis that no difference in bracket failure characteristics is noted when use of a new ceramic bracket debonding instrument is compared with the use of conventional pliers . MATERIAL S AND METHODS Thirty maxillary premolars were r and omly assigned to one of two groups . In group 1 , Clarity collapsible ceramic brackets ( 3 M Unitek , Monrovia , Calif ) were debonded with the use of conventional Utility/Weingart ( 3 M Unitek , Monrovia , Calif ) pliers . In group 2 , Clarity brackets were debonded with a new Debonding Instrument ( 3 M Unitek ) . For all teeth , the same bracket bonding system was used . Following debonding , teeth and brackets were examined under 10x magnification for assessment of bracket failure ( fracture ) and of residual adhesive on the enamel surface . Enamel surfaces were visualized with transillumination prior to bonding and after removal of the residual adhesive , so the effect of the debonding forces could be determined . RESULTS The results of Adhesive Remnant Index comparisons indicated that a statistically significant difference ( chi2 = 8.73 ; P = .013 ) in bond failure patterns was apparent when the two groups were compared . Brackets debonded with the new instrument showed a greater tendency for the adhesive to be removed from the tooth during debonding . CONCLUSIONS The hypothesis is rejected . Although the incidence of enamel damage following debonding was similar in the two groups , the use of the new Debonding Instrument decreased the incidence of bracket fracture BACKGROUND Enamel cracks , which may develop during debonding orthodontic brackets , may jeopardise the integrity of the enamel and detract from the appearance of the teeth . AIM To compare the adhesive remnant scores ( ARI ) , the number , lengths and directions of enamel cracks before bonding and after debonding metal orthodontic brackets with three different methods . METHODS Metal brackets were bonded with a self-curing orthodontic adhesive to the buccal surfaces of 75 recently extracted upper and lower premolars . The teeth were r and omly divided into three groups , and the brackets removed either with a side-cutter , a single-blade bracket remover or a two-blade bracket remover . The number , directions and lengths of the enamel cracks before bonding and after debonding were compared . The number of ' pronounced ' cracks ( i.e. cracks that could be identified with the naked eye ) and the ARI scores in each group were also compared . RESULTS After debonding , the number of enamel cracks and pronounced cracks , and the lengths of the enamel cracks increased in all groups ( p < 0.001 ) . There were no statistically significant differences between the groups . The ARI scores and the direction of propagation of the enamel cracks were not influenced by the debonding method used ( p = 0.73 ) . CONCLUSIONS Concerns about the enamel damage caused by the three methods of debonding justify caution . Despite widespread use of these methods , it would be sensible to search for methods that result in less enamel damage INTRODUCTION The purpose of this study was to evaluate the shear bond strength of orthodontic brackets and the effect of an enamel bonding agent ( EBA ) on enamel surface after debonding . METHODS Seventy-five extracted maxillary premolars were collected and r and omly divided into 3 groups of 25 . The enamel cracks were surveyed with a stereomicroscope . In the first group , 1 layer of EBA was applied before the adhesive resin . In the second group , 2 layers of EBA were used ; in the third group , no EBA was used . Bonding was followed by incubation for 48 hours at 37 degrees C and thermocycling for 1000 cycles . Debonding was performed with a shear force . The surfaces of the teeth were evaluated , and the length , depth , direction of cracks , and adhesive remnants on the enamel surface were recorded . Data were analyzed by using analysis of variance and paired sample s t tests . RESULTS There were no significant differences between the shear bond strengths ( P = 0.341 ) of the 3 groups , or in the direction , length , and depth of the cracks before and after debonding ( P > 0.05 ) . There was a significant increase in the number of cracks after debonding in the 3 groups ( P < 0.05 ) . The evaluation of adhesive remaining on the surface of the teeth indicated that most bond failures occurred at the resin-bracket interface . CONCLUSIONS The use of EBA does not enhance bond strength or provide greater protection to the enamel surface during debonding
target: Conclusions There is weak evidence indicating length and width of EMCs increase following bracket removal and the scientific evidence concerning quantitative evaluation of the number parameter before and after debonding is insufficient .
  However , there is a strong evidence that after debonding the number of EMCs is likely to increase .
background: Objectives To evaluate and compare the enamel microcracks ( EMCs ) characteristics ( qualitative and quantitative ) in the form of tooth damage before and after debonding from human teeth of in vitro studies .