Hamidreza Pakshir; R Rostami; AA Alavi
Abstract
Background and aim: Different adhesives have been used for bonding orthodontic brackets to teeth. The aim of this study was to evaluate the possibility of using Core Max II in bracket bonding by comparing it's shear bond strength with the two commonly used orthodontic adhesives; Transbond XT and Unite.
Subjects ...
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Background and aim: Different adhesives have been used for bonding orthodontic brackets to teeth. The aim of this study was to evaluate the possibility of using Core Max II in bracket bonding by comparing it's shear bond strength with the two commonly used orthodontic adhesives; Transbond XT and Unite.
Subjects and Methods: In this interventional study, 105 human premolars were divided into 3 groups of 35 each. After etching with 37% phosphoric acid, Dyna-Lock stainless steel brackets (3M Unitek, Monrovia, CA) with the average base surface area of 12.09 mm2 were bonded with three different adhesives: Core Max II (Sankin, Tokyo, Japan) Transbond XT (3M Unitek) and Unite (3M Unitek). The shear bond strength of 3 groups were measured by a universal testing machine (lnstron 3401, Canton, Mass) with cross- head speed of 0.5 mm/min. Adhesive Remnant Index (ARI) was determined under 10x magnification. For data analysis, SPSS statistical package was used.
Results: Mean shear bond strength of Core Max 11 (17.24± 3.2 MPa) was significantly higher than Transbond XT (15.44 ± 2.2 MPa) (P=0.009) but had not statistically difference with Unite (17.16 ± 3.7 MPa) (P=0.93). Evaluation of ARI indicated that 83% of Core Max II samples had score 0 or 1 and 17% had score 2 or 3. These percentages were 66% and 34% for Transbond XT and 77% and 23% for Unite, respectively.
Conclusion: In this study, it was concluded that: 1) Core Max II had a shear bond strength higher that Transbond XT and equal to Unite. 2) ARI of Core Max II showed a higher frequency of score 0 and 1, which indicated that after debonding, most of the adhesive remains on the bracket base. 3) Core Max II has the potential of being a good orthodontic adhesive. (IJO 2006; 1: 42 - 47)
Hooman Zarif; Hamid Reza Pakshir
Abstract
Impaction of the lower second molar is not a common problem (0.03%), but it is very challenging for orthodontists. Unilateral mandibular second molar impaction is the most popular form of second molar impactions. The etiology of which is related to some disturbances in physiological mandibular growth ...
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Impaction of the lower second molar is not a common problem (0.03%), but it is very challenging for orthodontists. Unilateral mandibular second molar impaction is the most popular form of second molar impactions. The etiology of which is related to some disturbances in physiological mandibular growth and tooth development. Other factors have been cited for this problem is iatrogenic such as space gaining procedures in mixed dentition. Treatment options depend on degree of tooth inclination, the position of third molar and desired type of tooth movement. Advantages of impacted molar uprighting arc functional, periodontal and restorative. In this case report, treatment of partially impacted second molars in a 12 year — old girl with class I malocclusion is presented. Uprighting of both second molars was performed in two stages. It was concluded that using continuous stainless steel wire with T-loop and gable bend is an effective method for correction of second molar inclination with the least risk of molar extrusion.