Debonding characteristics of orthodontic brackets subjected to intraoral stresses under different adhesive regimes: An in-vitro study (original) (raw)
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Background: Applying the recently suggested resin primer co-curing technique could save some of patients’ and orthodontists’ time. This study evaluated the efficiency of self-etch primer co-curing protocol in retaining orthodontic brackets. Methods: A self-etch orthodontic resin primer was pre-cured or co-cured together with the resin adhesive (Groups 1 and 2) to retain either non-coated or pre-coated orthodontic brackets (Subgroups 1 and 2) on the buccal surfaces of extracted premolars. The debonding stress values were evaluated immediately after bonding (category 1) and after exposure to cyclic intraoral hydraulic, thermal, and mechanical stress simulations (Category 2). The adhesive remanent index (ARI) was also assessed for each test category. Results: The co-cured primer provided higher immediate debonding stress values of both non- and pre-coated brackets (Tukey’s, P<0.05) than did the pre-cured primer. The delayed debonding stress values were lower than the immediately ass...
Evaluation of the debonding strength of orthodontic brackets using three different bonding systems
The European Journal of Orthodontics, 2007
The aim of this work was to investigate the stability of the bracket-adhesive-enamel interface, as a function of adhesive material and of debonding procedure, in order to assess which debonding technique is the least detrimental to the enamel. Ninety lower adult bovine incisors were selected and metallic orthodontic brackets were bonded using three adhesive systems: Concise, Transbond, and Fuji Ortho. Three different debonding procedures were used based on tensile, shear, and torsional stresses. One-way analysis of variance statistical analysis was employed to compare mechanical properties, while the adhesive remnant index was used to evaluate fracture properties. Each adhesive material used showed a statistical difference in tensile failure. The difference between shear and torsion failure loads was statistically signifi cant only for the Fuji GC sample (P < 0.01). The shear test was the most damaging to the enamel surface. Transbond luting resulted in greater adhesion than the Concise or Fuji Ortho systems. Fuji Ortho was more prone to accidental debonding, while Transbond tended to cause enamel lesions, since high loads were required to debond the bracket. Of the three modes examined, torsional debonding stress resulted in the least enamel damage.
In vivo bracket bond strength using two adhesive systems applied under wet and dry conditions
Acta odontológica latinoamericana, 2006
The purpose of this study was to investigate, in vivo, the bond strength of two adhesive materials: a moisture insensitive primer (MIP)* and a one step self etching primer (SEP)*, both used with Transbond XT* on dry and wet enamel and an adhesion time of 10-15 minutes. First or second upper and/or lower bicuspids (n = 124), to be extracted for orthodontic reasons, were used. A comparison of the materials' behavior was conducted under four different situations: 1) MIP on enamel etched and dry; 2) MIP on a surface etched and wetted with patient's saliva; 3) SEP on a dry field, 4) SEP on a saliva-wet enamel. For statistical analysis, Dunn-Sidak's multiple comparison test was applied with a probability of less than 0.05 (before correction). Stainless steel brackets with mesh-backed pads were bonded to the teeth. Bond strength was tested with modified orthodontic pliers on which a strain-gage was fixed to measure handle deformation while debonding. Moisture insensitive primer...
Journal of Orthodontic Science, 2016
Objectives: To assess in vitro the quantitative and qualitative debonding behavior of the AEZ debonding plier, compared to shear debonding force, in debonding orthodontic metal brackets. Materials and Methods: Thirty-two extracted premolars bonded with metal brackets were randomly divided into two equal groups according to the type of simulated debonding method; compressive bond strength (CBS) group using AEZ debonding plier (Ormco Corporation, USA) attached to the Instron machine, and shear bond strength (SBS) group using regular Instron attachments. All teeth were subjected to debonding forces, and debonding strength was assessed. The buccal surfaces were then examined, under a stereomicroscope, and adhesive remnants were scored using adhesive remnant index (ARI). Debonding strengths comparison was performed using the independent sample t-test. ARI score comparison was performed using the Mann-Whitney U-test. Correlation between debonding strength and ARI scores was performed using the Spearman correlation. Results: There was no significant difference in mean debonding strength between the SBS (M = 6.17 ± 0.77 MPa) and CBS (M = 6.68 ± 1.67 MPa) groups (P > 0.05). The CBS group showed significantly less adhesive remnants than the SBS group (P < 0.05); 62.5% of CBS group had ARI score 1, whereas 68.8% of SBS group had ARI score 3. No significant correlation between ARI and debonding strength was found (P < 0.05). Conclusion: SBS was found to produce similar debonding strength to the AEZ debonding plier in vitro. However, the AEZ debonding plier resulted in less adhesive remnant which is of great advantage for reducing chair-time during cleanup after debonding brackets.
American Journal of Orthodontics and Dentofacial Orthopedics, 2007
Introduction: The purpose of this study was to evaluate 3-dimensionally the changes on tooth surfaces after debonding orthodontic brackets and after removing residual adhesive and finishing. Methods: Sixty premolars were randomly divided into 2 groups, and brackets were bonded according to the manufacturers' instructions. Two types of orthodontic adhesives were used: resin-modified glass ionomer cement (group 1) and resin-coated adhesive precoated brackets (group 2). The brackets were debonded on a testing machine at a cross-head speed of 1 mm per minute. Models were made of each tooth before bonding, after debonding, and after removal of residual adhesive. The models were scanned with a 3-dimensional laser scanning machine, and the scanned images were analyzed by using modified analytical software. Results: The Mann-Whitney test showed significant differences in adhesive thickness and enamel loss between the 2 groups (P Ͻ.001). The mean (Ϯ SD) thickness for group 1 was 31.2 m (Ϯ 26.5 m), and the mean (Ϯ SD) thickness for group 2 was 102.7 m (Ϯ 79.71 m). The means (Ϯ SD) for enamel losses after cleaning and finishing the enamel surfaces were 22.8 m (Ϯ 17.67 m) for group 1 and 50.5 m (Ϯ 31.27 m) for group 2. Conclusions: Adhesive thickness and enamel loss due to orthodontic procedures can successfully be measured in vitro by using 3-dimensional laser scanning technology.
Acta Medica Academica
Objectives. The purpose of this in vitro investigation was to evaluate qualitatively the surface topography at the bracket-adhesive-enamel junction, bonded to the buccal and lingual surfaces of premolars with composite resin and resin-modified glass-ionomer orthodontic adhesives, using two methods of adhesive removal: a dental explorer and a micro brush. Methods. Forty premolar surfaces were allocated to four groups of 10/ each, 20/buccal and 20/lingual surfaces. The brackets were bonded to the surface of the enamel and any extra adhesive was removed with a dental explorer or a micro brush. Specimens were evaluated and scored by two calibrated independent raters, at the bracketadhesive-enamel junction, for adhesive overlap on the bracket, the smoothness of the surface, as well as the presence of projections and depressions, using a digital microscope. The Fisher-exact statistical test was conducted to compare the different groups. Results. Regardless of the method used to remove the adhesives , all groups showed partial or complete overlap of the adhesive on the bracket. No statistical difference was found between the groups for adhesive overlap (P=1.0). However, resin-modified glass-ionomer was found to be statistically significantly (P<0.05) better than composite resin in both smoothness and the lack of projections or depressions, regardless of the instrument of removal. Conclusion. Removing excess adhesive with a dental explorer or a micro brush is not an ideal method for adhesive removal, as partial or complete overlap of the adhesive on the bracket existed in all groups. On the other hand, resin-modified glassionomer was a superior material to composite resin for better smoothness and surface topography at the bracket-adhesive-enamel junction.
Journal of Multidisciplinary Dentistry, 2021
The shear bon strength (SBS) to brackets to the teeth, is necessary strength to resist orthodontic movements, mastication forces induced by food and other forces. The retention mechanism of the bracket base, the preparation of dental and the adhesive material affecting the adhesion between the metal brackets and tooth enamel. Therefore, the purpose of this study is to investigate different systems adhesion; Z100 (3M Unitek, USA), Transbond XT (3M Unitek, USA) and Trulock (RMO, USA) on the shear bond strength of brackets to the enamel. 135 first human premolars, mounted on an acrylic base, were divided into 3 groups of 45 pieces each. They are prepared following the same protocol and a same type of metal brackets bonded, light activated for 40 s, and stored. SBS was performed in an Instron at crosshead speed of 2.0 mm/min. Data were submitted to the Student t test. The Adhesive Remaining Index (ARI) was evaluated. The is no statistical difference between 3 groups. The ARI showed a pr...
Editorial Orthodontics: Bracket Materials, Adhesives Systems, and Their Bond Strength
Adhesive interfaces influence greatly clinical success of modern dentistry. Durability of the interface can be determined by using several in vitro testing methods. Shear bond strength tests are widely used in dentistry and they are well suitable for testing orthodontic materials bonded to teeth. The first study that analyzed shear bond strength of orthodontic appliances appeared in international literature in the late 1970s [1]. Nowadays, more than one thousand reports have been conducted in order to analyze various factors influencing shear bond strength of orthodontic brackets. Precise interpretation of the shear bond strength test results should, however, take into account other types of stress which are occurring at the interface during testing.
Cumhuriyet Dental Journal, 2022
The purpose of this in vitro study was to compare the shear bond strength (SBS) and adhesive remnant index of stainless-steel brackets bonded with different orthodontic adhesive systems. Materials and Methods: In our study performed on 60 premolar teeth extracted because of orthodontic reasons, MBT prescription 0.022'' stainless-steel brackets (Discovery Smart®, Dentaurum, Germany) were used. Teeth randomly divided into 3 groups, bonding was performed with Group 1: Trulock Light Activated Bonding System (RMO, USA), Group 2: Bisco Ortho Bracket Paste LC (Bisco, USA), Group 3: Transbond XT Light Cure Adhesive (3M, USA). SBS and residual adhesive indexes (ARI) were evaluated by breaking the samples. Adhesive residues were cleaned with tungsten carbide burs from the surfaces of the teeth, rebonding was made after sanding the brackets' surfaces. SBS and ARI values were re-evaluated. One-way ANOVA test were used for statistical analysis of the data, p<0.05 was considered statistically significant. Results: Statistically significant differences were observed between Group 1 and Group 2 in comparison to the first SBS values of three different orthodontic adhesive systems to enamel (p <0.05). Among the adhesive systems, only a statistically significant difference was found between the first bonding values and the rebonding values of Group 2 (p <0.05). There was no statistically significant difference between the first and rebond strengths of the other two adhesive systems. Rebonding values of three different orthodontic adhesive systems were very close to each other. Conclusions: The results of this in vitro study suggest that the adhesive systems developed for using in orthodontics can show clinically enough bond strength even if the rebonding strengths of the falling stainless-steel brackets to the same enamel surfaces decrease slightly.
Iranian Journal of Orthodontics, 2022
The aim of the in vitro study was to examine the enamel surface after the application of four different methods for adhesive removal following the bracket debonding procedure, as well as to compare their effects on enamel surface. Methods: Premolars (n=60) were randomly assigned to four groups. After initial debonding and recording the shear bond strength (SBS), adhesive remnant index (ARI) scores were assessed. The removal method for each of the four groups was the use of 1) a round bur, 2) rubber wheel bur, 3)12 fluted tungsten carbide bur, and 4) scaler. After that, teeth in all four groups were kept in artificial saliva for one month. After rebonding with a new bracket, again the SBS and ARI scores were measured. Two representative samples from each group were examined under a scanning electron microscope. ……. Pvalue <0.05 was considered as significant. ANOVA test was used to assess the SBS association within the group. Paired T test was used to assess the SBS between the group. fisher's exact test was performed to compare ARI index before and after. Results: There was significant decrease in secondary SBS value in group 1 but significant increase in secondary SBS value in group 3, and a slight decrease in SBS value in group 4. In SEM images, there were composite remnants in all the four groups with fewer remnants in group 2. Enamel surface damage was observed in the SEM image of group 3. ARI scores showed no significant difference. Conclusion: Adhesive remnant removal efficiency of the round bur and scaler are less. Rubber wheel bur is a good choice of instrument for removal of adhesive remnants from tooth surface as it does not affect the bond strength. Tungsten carbide bur shows good results, as secondary bonding SBS value increased. Significant difference between ARI scores did not exist, indicating a higher number of mixed type failure in all groups.