Frictional Resistance of Three Types of Ceramic Brackets

Abstract

ObjectivesTo investigate the static frictional resistance at the bracket/archwire interface in two recently introduced bracket systems and compare them to conventional ceramic and conventional metal bracket systems. Three variables were considered including the bracket system, archwire type and archwire angulation.Material and MethodsFour bracket systems were tested in vitro: Self ligating ceramic, ceramic with metal slot and module, conventional ceramic with module and conventional metal with module. A specially constructed jig and an Instron testing machine were used to measure the static frictional resistance for 0.014 inches round and 0.018 x 0.025 inches rectangular stainless steel wires at 0° and 7° angulations. Main outcome measures: static frictional force at the bracket/archwire interface; recorded and measured in units of force (Newtons).ResultsSelf ligating ceramic and metal slot ceramic bracket systems generated significantly less static frictional resistance than conventional ceramic bracket systems with the wire at both angulations (P < 0.05). Changing the wire from 0.014 round to 0.018 x 0.025 rectangular wire significantly increased frictional forces for metal slot ceramic and conventional metal bracket systems (P < 0.01). Increasing wire angulation significantly increased frictional resistance at the bracket/archwire interface for all four types of bracket systems tested (P < 0.001).ConclusionsCompared to conventional ceramic, self ligating ceramic and metal slot ceramic bracket systems should give improved clinical performance, matching that of conventional metal brackets.

Fricção estática e dinâmica de brackets cerâmicos autoligáveis e convencionais

“…Estudos anteriores já haviam mostrado que quanto maior a angulação de segunda ordem entre o bracket e o fio ortodôn-tico, maiores os valores de fricção. 10,19,38,39 Os valores mais baixos de fricção estática e dinâmica, para todas as angulações, foram obtidos com os brackets Damon Clear. Sendo brackets autoligáveis passivos, o arco não sofre a ação de uma força perpendicular, ao contrário do que sucede com os grupos em que se usaram ligaduras elastoméricas.…”

“…Sendo brackets autoligáveis passivos, o arco não sofre a ação de uma força perpendicular, ao contrário do que sucede com os grupos em que se usaram ligaduras elastoméricas. 39 Os resultados deste estudo concordam com estudos anteriores, em que os brackets autoligáveis apresentaram valores de fricção menores comparativamente aos convencionais com ligaduras elastoméricas 9,39,40 que, ao pressionarem o arco em direção ao bracket, aumentam a fricção e consequentemente a resistên-cia ao movimento dentário. 41 No entanto, a redução de fricção com brackets autoligáveis passivos é menos significativa quando o fio utilizado preenche totalmente a ranhura do bracket.…”

Antimicrobial effect, frictional resistance, and surface roughness of stainless steel orthodontic brackets coated with nanofilms of silver and titanium oxide: a preliminary study

“…Three of the orthodontic main concerns are (1) friction of orthodontic appliances and its various biological and mechanical adverse effects, (2) the accumulation of bacteria around the brackets and its adverse effects on the health of surrounding tissues, and (3) surface roughness of appliances (Ahn, Lim, & Lee, ; Amini et al, ; Arash, Anoush, Rabiee, Rahmatei, & Tavanafar ; Arash, Rabiee, Rakhshan, Khorasani, S., & Sobouti, 2015b; Brusca, Chara, Sterin‐Borda, & Rosa, ; Hain, Dhopatkar, & Rock, ; Nanda, ; Omana, Moore, & Bagby, ; Ryu et al, ; Tecco et al, ; Van Gastel et al, ; Williams & Khalaf, ).…”

“…Orthodontic tooth movement relies on sliding (Nanda, ; Williams & Khalaf, ) which causes friction, defined as a force resisting the relative motion of two contacting objects (Arash et al, ; Hain et al, ; Nanda, ; Tecco et al, ). Static frictional resistance wastes about 50–60% of the exerted orthodontic force, and also can cause various complications, such as locking the bracket and stopping the dental movement or tilting the teeth (Arash et al, ; Hain et al, ; Nanda, ; Omana et al, ; Tecco et al, ; Williams & Khalaf, ).…”

Are self-ligating brackets an advantageous alternative for non-extraction treatments?

“…The friction resistance proved to be lower with ceramic and metal (stainless steel) self-ligating brackets than with conventional ceramic brackets 39 .…”