Enamel cracks and ceramic bracket failure during debonding in vitro. The Effects of Composite Resin Types and Debonding Pliers on the Amount of Adhesive Remnants and Enamel Damages: A Stereomicroscopic Evaluation Evaluation of enamel damages following orthodontic bracket debonding in fluorosed teeth bonded with adhesion promoter The effects of bracket removal on enamel. Bond strength with APF applied after acid etching. Orthodontic bracket removal using conventional and ultrasonic debonding techniques, enamel loss, and time requirements. Remineralization of Artificial Caries in Primary Teeth by Grape Seed Extract: An In Vitro Study
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 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 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 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 One tenet of successful orthodontic therapy is to complete treatment without decalcification , hypocalcification , or discoloration of the natural dentition . Fluoride application has been shown to reduce demineralization of enamel . The purpose of this study was to see if fluoride could be incorporated into enamel before orthodontic bracketing without adversely affecting bond strength . Forty extract adolescent human premolars were r and omly divided into two equal groups with 20 teeth each . Group 1 served as control group , and group 2 ( experimental ) was immersed in 1.23 % acidulated phosphate fluoride for 4 minutes after acid etching . The buccal surfaces of all 40 teeth were then bonded with the same type of metal bracket and debonded with an Instron machine . The debonding interface was observed with scanning electron microscopy ( SEM ) . The mapping was calculated with energy dispersive x-ray spectrometry . The results showed that the bond strength of group 1 was significantly greater than that of group 2 . The enamel detachment ( enamel fracture ) was found in the experimental group only . Although the application of acidulated phosphate fluoride to a tooth can prevent dental decay or decalcification , the bond strength decreases and enamel detachment is found after debonding . The result shows that the application of acidulated phosphate fluoride after acid etching enamel has an adverse effect on orthodontic bond strength of human enamel The purpose of this study was to examine the effects of ultrasonic orthodontic bracket removal and cleanup and compare them with conventional debonding and cleaning of the enamel surfaces with burs and polishing disks . The amount of enamel loss and time for bracket removal and clean-up were also addressed . Thirty extracted human premolars were collected . The teeth were r and omly placed in one of the three debonding groups : debonding with orthodontic pliers and enamel clean-up with finishing burs and polishing disks ( group 1 ) , debonding with orthodontic pliers and ultrasonic clean-up of the enamel surface ( group 2 ) , and ultrasonic debonding enamel clean-up ( group 3 ) . The teeth were stored for 48 hours in 100 % humidity before bracket removal . All brackets were then removed . Polyvinyl siloxane impressions were made before and after bracket removal . Direct measurements of the teeth in micrometers were made at all steps . An additional 30 teeth were similarly prepared , and the brackets were debonded and cleaned-up as in the three groups previously described . The total time for bracket removal and enamel clean-up for each group was recorded in seconds . ( ABSTRACT TRUNCATED AT 250 WORDS Background and aims . Promoting remineralization is the ultimate goal of clinical prevention of caries lesion . The present in vitro study aim ed to investigate the effect of grape seed extract ( GSE ) on artificial enamel caries in primary human teeth . Material s and methods . Seventeen human sound primary incisors were sectioned mesiodistally . The tooth slices were placed in a demineralizing solution for 96 hours at 37ºC and 50 % relative humidity to create lesions . The demineralized fragments of each tooth were r and omly divided into two case ( immersed in GSE solution in phosphate buffer for 8 days ) and control ( immersed in distilled water ) groups . The sample s were subsequently evaluated using a scanning electron microscope and a micro-hardness tester . Data were analyzed using independent t-test . Results . The mean ± SD micro-hardness values for the case and control groups were 358.6±83.42 and 296.51± 69.41 , respectively . Grape seed extract significantly increased the micro-hardness of the lesions ( P=0.03 ) . The morphology  of GSE treated enamel was clearly different from that in the control group , and there were deposits of scaffolding insoluble complexes on the enamel surface . Conclusion . GSE enhanced the remineralization process of artificial enamel lesions of primary teeth , and thus , might be considered an effective natural agent in non-invasive dentistry
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 .
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 .