A Comparative study of Resistance during Tooth Retraction Using Ceramic Bracket and Ceramic Bracket with Metal Slot: In-Vitro Study

Frictional resistance is an important counterforce to orthodontic tooth movement during sliding mechanics. This study was carried out to evaluate the effect of ceramic bracket and ceramic bracket with metal slot -archwire‐ ligation combinations on “resistance to sliding” during simulated canine retraction on typodont model. The frictional resistance was tested between Ceramic brackets (3MUNITEK Clarity ADVANCED, Monrovia, CA) and Ceramic brackets with metal slot (3 MUNITEK METAL REINFORCED, Monrovia, CA). Eleven different rectangular archwires of 0.016 × 0.022 inch were used in the study as follows: Stainless steel and NiTi (Both archwires from Ortho Organizers, San Marcos, CA), three labial coated rectangular archwires: Stainless steel (Noninium White, DENTAURUM, Ispringen, Germany), NiTi (Rematitan LITE,DENTAURUM, Ispringen, Germany) and thermoactive NiTi (Tensic White, DENTAURUM, Ispringen, Germany), five full coated archwires: Stainless steel and NiTi (Tooth Tone Archwires, ORTHO TECHNOLOGY, Tampa, Florida, USA), Stainless steel and NiTi (Ultresthetic Tooth Colored Archwires, G&H ORTHODONTICS, Greenwood, Indiana, USA) and NiTi (Memoria Natura Preformed Archwires, LEONEAMERICA, Oxnard, CA) and Rhodium coated (Memoria Mimetic with Rhodium coating, LEONE S. P. A, Italy). The Ligation materials used were: Stainless steel ligature 0.009 inch (Ortho Organizers, San Marcos, CA) and regular clear elastomeric module (Ortho Organizers, San Marcos, CA).All tests were carried out in a dry state on an Instron universal testing machine (crosshead speed: 0.5 mm/min). The highest mean frictional resistance was found in ceramic brackets with nickel‐ titanium archwire ligated with elastomeric modules while minimum frictional resistance was found in metal slot ceramic brackets generated significantly lower frictional forces than ceramic brackets. Coated archwires shows highly significant reduction of the frictional resistance than their corresponding uncoated archwires. Ceramic brackets with metal slot and rhodium coated SS archwires seem to be a good alternative in space closure with sliding mechanics in patients with esthetic demands.