The aim of this study was to compare the pain experience among orthodontic patients treated with self-ligating brackets SmartClip® (3M Unitek, Monrovia, California, USA) and conventional brackets Victory series® (3M Unitek, Monrovia, California, USA). We used a controlled clinical trial study design to compare 69 patients treated with self-ligating to 70 patients treated by conventional brackets. The nickel-titanium archwires 0.012-in were engaged after bonding both arches on the first day; and the visual analogue scale (VAS) was used to assess the pain experience of subjects for the first seven treatment days. The pre-treatment dental study models were assessed by the Little’s irregularity index to quantify the groups’ malalignment characteristics. The self-ligating brackets reported lower pain experience than the conventional group on the first five treatment days. However, the sixth day showed 1.75 mm higher visual analogue score than conventional brackets, with almost equal pain level on the seventh day. The group differences throughout the first week were neither clinically nor statistically significant. The pain experiences in both groups decreased steadily from the third treatment day to the end of the first week of treatment. Based on the study findings, the pain experience during initial alignment is not influenced by the brackets’ ligation type. The pain experience tends to decrease steadily from the third treatment day to the end of the first week of treatment irrespective of the bracket type used.
Orthodontic Brackets, Orthodontic Appliances

Previous study had shown the diversities in the propriety for optimal bond strength on the concentration of the etchant. The aim of present study in vitro was to evaluate and compare the shear bond strength of orthodontic brackets to enamel and to measure the depth of etch on the phosphoric acid concentrations. A hundred and seventy six extracted bovine lower centrals were ground to yield flat surfaces and etched by the concentration 0%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% and 85% of phosphoric acid respectively during 60 seconds. The shear bond strength of orthodontic brackets, the depth of etch and surface roughness of the enamel were measured, and scanning electron microscopic observations on the etched enamel surfaces were carried out. The data obtained from the very experiments were processed and statistically analyzed and evaluated. The gradual increase in the depth of etch to enamel as the accretion of the concentration of the phosphoric acid up to 40-50% and decline henceforth were manifested. The surface roughness showed no correlation with the depth of etch, yet moderate correlation with the shear bond strength of brackets. Scanning electron microscopic investigation revealed that morphological patterns of the etched enamel surfaces for 5% to 40% of concentrations were even and homogenous, and those for 50% as well as 60% exhibited the overetched and unhomogenous. The shear bond strengths from 10% to 60% of concentration showed no statistically significant differences. It was suggested that the shear bond strengths at 5% and 70% were sufficient to tolerate the force levels of the ordinary orthodontic treatment notwithstanding to be significantly lower than those from 10% to 60% phosphoric acid solution.
Dental Enamel* ; Orthodontic Brackets*

This study was performed to evaluate clinical practicality of the rebonding method with flowable resin without the removal of the residual resin on the debonded teeth and debonded bracket base after debonding. The samples of the control group (group I) were rebonded with Transbond XT(R) using the usual rebonding method after the residual resin was removed. At experimental group, the brackets were rebonded with Transbond XT(R) (group II) and CharmFil Flow(R) (group III) without removal of residual resin which is the possibility becoming the index for rebonding to similar position with initial bonding. The shear bond strength of the each group was measured. Patterns of bonding failure were evaluated with modified ARI score, and the shear bond strength according to patterns of bonding failure at experimental group was compared. Between the control group (6.51 +/- 1.21 MPa) and the group II rebonded with Transbond XT(R) (6.30 +/- 1.01 MPa) did not have significantly difference in the shear bond strength (p = 0.534), and the shear bond strength of group II was significantly lower than the group III rebonded with CharmFil Flow(R) (7.29 +/- 1.54 MPa) (p = 0.009). At control group, there was not large difference in distribution of bonding failure pattern. But at experimental group, bond failure did not occur in interface between the resin-enamel. and bond failure between the resin-bracket, within the resin was distributed similarly. There was not significantly difference in the shear bond strength according to patterns of bonding failure at experimental group (p > 0.05). The result of this study showed that the method suggested in this study and flowable resin as rebonding adhesive could be useful in clinically.
Adhesives ; Orthodontic Brackets* ; Tooth

The aim of this study was to compare the shear bond strengths of orthodontic bracket with Conventional primer (CP), Moisture insensitive primer (MIP), and Self-etching primer (SEP). In addition, the effect and the timing of saliva contamination on shear bond strength was evaluated.A total of 135 bovine mandibular incisors were used in the study and divided into 3 groups. Group I, II and III were used CP, MIP, SEP, respectively. Each group was then divided into three subgroups: the group without saliva contamination, the group with primer application after saliva contamination, and the group with saliva contamination after primer application. After the primer application, the metal bracket for the lower incisor was attached and the shear bond strength was measured.The mean shear bond strengths was highest with CP and lowest with SEP in dry condition. However, CP showed a significant decrease in shear bond strength in the presence of saliva contamination. MIP and SEP showed no significant decrease in shear bond strength with saliva contamination.
Incisor ; Orthodontic Brackets ; Saliva

ABSTRACT Duration of orthodontic treatment becomes major concern. The present study compared shear bond strength (SBS) and adhesive remnant index (ARI) values of different adhesive systems with different application methods on rebonding process of retrieved orthodontic brackets. Eighty premolar teeth were equally divided into five groups. Transbond XT (TXT) which belongs to total-etch system was used in Group 1 as the control group. Nova Compo-SF (NC) and Vertise Flow (VF) (Kerr Dental, Italy) which are self-adhering flowable composites were used in Group 2 (NC+etch) and Group 3 (VF+etch) respectively with additional etching before application. Group 4 (NC) and Group 5 (VF) were used by following instructions of each brand. The brackets were debonded with a bracket removing plier and rebonded with the same procedures after sandblasting of the bracket and surface cleaning of the enamel. SBS and ARI were measured for each sample. Comparison between all groups was performed by Kruskal-Wallis test and chisquare test. The highest SBS was observed in NC+etch (median = 11.44, mean = 13.49±9.42), followed by NC (median = 10.17, mean = 11.35±6.55), TXT (median = 6.36, mean = 8.06±6.33), VF+etch (median = 5.68, mean = 6.75±4.58), and VF (median = 2.62, mean = 2.92±2.57), respectively. ARI 1 was observed in 81.3% of TXT whereas 62.5% of NC+etch. ARI 1, 2, and 3 were equally distributed in VF+etch group (31.3%). ARI 5 was observed in 37.5% of NC and 62.5% of VF. Analyses referred to statistically significant differences between five groups regarding both SBS and ARI (p < 0.001). As NC showed the highest SBS on rebonding process, it can be a promising alternative to TXT which is the gold standard.
Dental Materials ; Orthodontic Brackets

The purpose of this study was to evaluate shear, tensile and shear/tensile combined bond strengths(SBS, TBS, S/TBS) in various orthodontic brackets bonded to human teeth with chemically cured adhesive (Ortho-one, Bisco, USA). Five types of metal brackets with various bracket base configurations (Micro-Loc base(Tomy, Japan), Chessboard base(Daesung, Korea), Non-etched Foil Mesh base(Dentarum, Germany), Micro-Etched foil Mesh base(Ortho Organiners, USA). Integral base(Unitek, USA)) were used in this study. Shear, tensile and shear/tensile combined bond strengths according to the direction of force were measured by universal testing machine. The bracket base surface after bond strength test were examined by stereoscope and scanning electron microscope. The assessment of remnant on bracket base surface was carried out by ARI(adhesive remnant index). The results obtained were summarized as follows ; 1. In all brackets, SBS was in the greatest value(p<0.05), TBS was in 50% level and S/TBS was in 30% level of SBS. 2. In bond strength, Micro-Loc base bracket showed the maximum bond strength(SBS:22.68+/-1.37kgf, TBS:11.37+/-0.42kgf, S/TBS:6.69+/-0.34kgf) and Integral base bracket showed the minimum bond strength(SBS:10.52+/-1.27kgf, TBS:4.27+/-1.08kgf, S/TBS:2.29+/-0.58kgf) (p<0.05). 3. In bond strength per unit area Integral base bracket showed the minimum value, Micro-Loc base and Chessboard base brackets were in similar value(p>0.05). Non-Etched Foil Mesh base and Micro-Etched Foil Mesh base bracket were similar in SBS and TBS(p>0.05), But Micro-Etched Foil Mesh base bracket was greater than Non-Etched Foil Mesh base bracket in S/TBS(p<0.05). 4. Bond failure sites were mainly between bracket base and adhesive, therefore ARI scores were low.
Adhesives ; Humans ; Orthodontic Brackets ; Tooth

The purpose of this study was to evaluate the bond strength of orthodontic brackets bonded to metal bar with chemically cured adhesive (Ortho-one, Bisco Co, USA) in various types and directions of force application. Three types of metal bracket with different bracket base configurations; Micro-Loc base(Tomy Co, Japan), Chessboard base(Daesung Co, Korea), Non-etched Foil-Mesh base(Dentaurum, Germany); were used in this study. Peel, shear, tensile bond strengths were measured by universal testing machine and compared each other. The peel force directions applied were 0degrees, 15degrees, 30degrees, 45degrees, 60degrees, 75degrees, 90degrees. And then, in consideration of the different surface area of the bracket bases, the bond strength per unit area were calculated and compared. The results obtained were summarized as follows : 1. The bond strengths according to the types and the directions of the forces were greatest at the shear forces in all three bracket base configuration groups(p < 0.01). 2. As the peel force direction grew higher in degree, peel bond strength decreased. The patterns of peel bond strength change according to force direction was similar in all three bracket base configurations. The minimum bond strength was 60 degree-peel bond strengths in all three bracket base configurations. 3. In Micro-Loc base group, minimum peel bond strength(60PBS) was in 29% level of shear bond strength and 52% level of tensile bond strength. In Chessboard base group, 60PBS was in 34% level of shear bond strength and 61% level of tensile bond strength. In Non-etched Foil-Mesh base group, 60PBS was in 34% level of shear bond strength and 55% level of tensile bond strength. 4. The bond strengths per unit area were lowest in Non-etched Foil-Mesh base group and highest in Chessboard base group(p < 0.05). However, there were no differences in shear bond strength, tensile bond strength, 75PBS and 90PBS per unit area between Micro-Loc and Chessboard base groups.
Adhesives ; Orthodontic Brackets ; Tensile Strength

This study was conducted to see the effect of TiN ion-plating on the bond strength of orthodontic bracket. Three stainlesssteel brackets with different base types were chosen; when TiNTion-plated brackets and non ion-plated brackets were bonded to the teeth, initial and long-term bond strength were measured The observations of bonding surface and failure sites through the scanning electron microscope were analysed and compared. The summary of this study was as follows: When TiN ion-plating was not applied, the Micro-Loc type was the highest in bond strength atter 24 hours as 5.89+/-1.77 MPa, followed by 4.27+/-1.12 MPa for Foil Mesh type and 2.64+/-0.58 MPa for Undercut type(P<0.05). Under TiN ion-plating, the bond strength after 24 hours showed: Micro-Loc type - 6.26+/-1.51 MPa, Foil Mesh type - 7.45+/- 2.01 MPa, Undercut type - 2.93+/-0.84 MPa Unlike in the case of non ion-plating, Foil Mesh type showed a higher strength than Micro-Loc type, with Undercut type still showing the lowest bond strength(P<0.05). The bond strength, after 24 hours, increased in case of ion-plated in all 3 types, but a significant increase was shown only in Foil Mesh type(P<0.001). Under a long-term immersion, regardless of ion or non ion-plating, bond strength in general increased over the initial bond strength(one day), with more stability. Through scanning electron microscopic observation of bonding surface, it was found that, regardless of the bracket base type or the application of ion-plating, the resin was thoroughly spreaded into bracket base to form a solid bonding surface between the bracket and the tooth.. This was also true in case of a long-term immersion. The scanning electron microscopic observation of failure sites revealed diverse failure patterns.
Immersion ; Orthodontic Brackets* ; Tin* ; Tooth

OBJECTIVE: The purpose of this study was to evaluate the clinical usefulness of 4 self etching primers by measuring the shear bond strength of orthodontic brackets and examining the failure pattern of bracket-tooth interfaces. METHODS: Seventy-five, defect-free, premolars were randomly assigned into five groups: control group (37% phosphoric acid + Transbond XT primer) and self etching primer treated groups (Transbond Plus self etching primer, Unifil bond, Clearfil SE bond, and Adhese). The shear bond strength was measured with a universal testing machine and the amount of residual adhesive remaining on the brackets after debonding was assessed by the adhesive remnant index (ARI). RESULTS: The results showed that the groups conditioned with self etching primer had significantly lower shear bond strength than the control group (p < 0.05), although clinically acceptable. However, there were no significant differences in shear bond strength among the self etching primer groups (p > 0.05). Evaluation of the ARI scores indicated there was less resin remnant on the teeth in the groups conditioned with self etching primers, although not statistically significant. CONCLUSION: The results of this study suggest that all four of the self etching primers have shown acceptable bond strength for clinical use.
Adhesives ; Bicuspid ; Orthodontic Brackets ; Tooth

OBJECTIVE: Bonding forces of brackets to enamel surfaces may be affected by the procedures used for bleaching and enamel etching. The aim of this study was to investigate the bonding strength of orthodontic brackets to laser-etched surfaces of bleached teeth. METHODS: In a nonbleached control group, acid etching (group A) or Er:YAG laser application (group B) was performed prior to bracket bonding (n = 13 in each group). Similar surface treatments were performed at 1 day (groups C and D; n = 13 in each subgroup) or at 3 weeks (groups E and F; n = 13 in each subgroup) after 38% hydrogen peroxide bleaching in another set of teeth. The specimens were debonded after thermocycling. RESULTS: Laser etching of bleached teeth resulted in clinically unacceptable low bonding strength. In the case of acid-etched teeth, waiting for 3 weeks before attachment of brackets to the bleached surfaces resulted in similar, but not identical, bond strength values as those obtained with nonbleached surfaces. However, in the laser-etched groups, the bonding strength after 3 weeks was the same as that for the nonbleached group. CONCLUSIONS: When teeth bleached with 38% hydrogen peroxide are meant to be bonded immediately, acid etching is preferable.
Dental Enamel ; Hydrogen Peroxide ; Orthodontic Brackets ; Tooth