In vitro frictional behavior and wear patterns between contemporary and aesthetic composite orthodontic brackets and archwires

• Published in: Wear 2006-11, Vol.261 (10), p.1121-1139
• Main Authors: Sadique, Sarder Elius, Ramakrishna, Seeram, Batchelor, Andrew W., Bing, Chua Han
• Format: Article
• Language: English
• Subjects: Abrasive wear; Aesthetic; Applied sciences; Biological and medical sciences; Braided composite bracket; Coated archwire; Composites; Diseases of the upper aerodigestive tract; Ent and stomatology; Exact sciences and technology; Forms of application and semi-finished materials; Friction, wear, lubrication; Machine components; Mechanical engineering. Machine design; Medical sciences; Polymer industry, paints, wood; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Saliva; Surface roughness; Technology of polymers
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2006.03.035

This study evaluates the effects of surface roughness, saliva and bracket materials on in vitro frictional resistance of contemporary and aesthetic orthodontic brackets during the sliding of archwires against elastomeric ligature. Eight various brackets were investigated together with stainless steel (SS) archwires of several shapes. The sliding force involved in a ligated bracket–archwire combination was measured in an Instron by a self-designed jig. The interfaces were also examined using scanning electron microscope (SEM) to simulate sliding mechanics and abrasive/adhesive wear of the bottom surfaces of the bracket slots, which were observed under dry condition. Round SS archwires (SRO-OR) demonstrated the lower frictional force compared to coated round SS archwire (SRO-AW) and the flat SS archwire (rectangular and square) surfaces for most of the brackets. Braided composite bracket without a metal slot had the least resistance when sliding with SRO-OR archwire whilst the composite bracket (Spirit MB) with a metal slot demonstrated the lower resistance. Ceramic bracket (Inspire) without a metal slot, which also reflected severe wear patterns produced a significantly larger frictional force for SRO-AW. The presence of saliva had a consistent effect in increasing the friction, which counters the inconsistency reported in the literature. The soft-coated surface of SRO-AW archwire confirms sliding difficulty in sliding on the hard surface of bracket slot. A smoother surface correlates with a lower frictional force according to the surface roughness values.