Comparison of changes in retentive force of three stud attachments for implant overdentures

Abstract

PURPOSEThe aim of this study was to compare the changes in retentive force of stud attachments for implant overdentures by in vitro 2-year-wear simulation.MATERIALS AND METHODSThree commercially available attachment systems were investigated: Kerator blue, O-ring red, and EZ lock. Two implant fixtures were embedded in parallel in each custom base mounting. Five pairs of each attachment system were tested. A universal testing machine was used to measure the retentive force during 2500 insertion and removal cycles. Surface changes on the components were evaluated by scanning electron microscopy (SEM). A Kruskal-Wallis test, followed by Pairwise comparison, was used to compare the retentive force between the groups, and to determine groups that were significantly different (α<.05).RESULTSA comparison of the initial retentive force revealed the highest value for Kerator, followed by the O-ring and EZ lock attachments. However, no significant difference was detected between Kerator and O-ring (P>.05). After 2500 insertion and removal cycles, the highest retention loss was recorded for O-ring, and no significant difference between Kerator and EZ lock (P>.05). Also, Kerator showed the highest retentive force, followed by EZ lock and O-ring, after 2500 cycles (P<.05). Based on SEM analysis, the polymeric components in O-ring and Kerator were observed to exhibit surface wear and deformation.CONCLUSIONAfter 2500 insertion and removal cycles, all attachments exhibited significant loss in retention. Mechanism of retention loss can only be partially explained by surface changes.

Alternative fixation system for implant-retained overdenture: case report

“…For overdentures, retention and stability characteristics are provided by the implants through the fixation system, classified as splinted, such as bar-type, and non-splinted, such as era®, magnetic and O-ring [4]. The shape of the dental arch, space inter-arches, implant placement, ease of adjustment, manual dexterity, and patient agreement will determine the most appropriate system choice [5]. Ball attachments are easy to insert, remove, hygiene, and are generally cost-effective [6][7][8].…”

Effect of bar cross-section and female housing material on retention of mandibular implant bar overdentures: A comparative in vitro study

“…Studs and bars are the anchorage systems that are commonly used in mandibular two-implant-retained overdentures (2-IODs). [ 5 6 7 8 9 ] Splinting of the implants with a metal bar provides some biomechanical advantages. [ 2 10 ] This overdenture design has demonstrated superior retentive capacities with favorable stability over stud systems.…”

Desenvolvimento de dois modelos de mini-implantes e componentes protéticos: correlação da macroestrutura e propriedades mecânicas

“…O desgaste dos componentes do sistema de fixação da overdenture, devido às cargas funcionais, trajetória de inserção/remoção da prótese, angulação dos implantes e presença de hábitos parafuncionais (KIM et al, 2015) é a complicação prostodôntica mais comum (33%) entre as restaurações com implantes (ELSYAD; ELHADDAD; KHIRALLAH, 2016;SHASTRY et al, 2016), e ocorre nos primeiros 12 meses de uso, gerando a necessidade de manutenções periódicas (MACENTEE; WALTON;GLICK, 2005, MERICSKE-STERN et al, 2009. No estudo, os o-rings tiveram perda de retenção de 18,7% após 30 meses de simulação, o poliacetal aumento de 30,5% e o PTFE redução de 18,2%, tais resultados foram melhores se comparados a outros estudos (RODRIGUES et al, 2009) que encontraram perda de retenção em o-rings de 16,6%, após simulação de 6 meses de uso da prótese e 57,1%, após 24 meses.…”

“…Para implantes padrão recomenda-se no mínimo 20 N de retenção para o bom funcionamento da overdenture (KIM et al, 2015). Em contrapartida, não existe um valor de referência para as sobredentaduras mini-implantes retidas.…”

“…A perda de retenção gradual e a necessidade de trocas periódicas são algumas das desvantagens dos o-rings, sobretudo em implantes não paralelos (CHAVES et al, 2016), comprometendo a biomecânica e sucesso das overdentures implanto retidas (KIM et al, 2015).…”