Comparison of Microleakage and Bond Strength in Metal and Ceramic Brackets Cured by Conventional and...

The study explores the impact of microleakage on bracket (metal/ceramic) debonding and the occurrence of white spot lesions during orthodontic treatment. Various curing techniques are employed to assess shear bond strength (SBS) and microleakage in both metal and ceramic brackets.

A total of 120 samples were divided into six groups, each consisting of 20 samples. The groups were categorized based on the bracket material (metal or ceramic) and further subdivided according to the light-emitting diode (LED) curing method (traditional, transillumination, or combination). Fifty percent (60 samples) of each group were allocated for SBS evaluation, while the remaining 50% (60 samples) were used for microleakage assessment. The buccal enamel surfaces of all teeth in the six groups were etched and coated with a uniform layer of sealant. Stainless steel and ceramic maxillary premolar brackets were affixed using Transbond XT adhesive and light-cured with an LED unit. SBS was measured using the Instron ElectroPuls E3000 universal testing machine, and microleakage was examined using a stereomicroscope.

One-way analysis of variance (ANOVA) with Bonferroni post-hoc test revealed significant differences in SBS among the six groups. Group IV exhibited the minimum SBS mean (7.02 MPa), while group VI displayed the maximum SBS mean (21.73 MPa). Microleakage assessment demonstrated that group IV had a maximum depth of 0.26 mm using the transillumination method, whereas group VI showed a minimum depth of 0.14 mm with the combination technique.

Brackets cured with a combination of conventional (5 seconds) and transillumination (5 seconds per bracket) methods exhibited significantly higher SBS. Conversely, group IV, cured solely with the transillumination technique (10 seconds per bracket), demonstrated the lowest strength. In terms of microleakage, group VI, treated with the combination technique, displayed the shallowest depth, while group IV, cured exclusively with transillumination, showed the greatest depth of microleakage. These findings underscore the importance of the curing method in influencing both SBS and microleakage, offering valuable insights for optimizing orthodontic bracket placement techniques.

Lenin A, Anbarasu P, S SK, et al. Comparison of Microleakage and Bond Strength in Metal and Ceramic Brackets Cured by Conventional and Transillumination Methods: An In-vitro Evaluation. Int J Clin Pediatr Dent 2024;17(9):999-1003.