Comparison of six different CAD/CAM retainers vs. the stainless steel twistflex retainer: an in vitro investigation of survival rate and stability.
J Orofac Orthop
; 2023 Jun 28.
Article
en En
| MEDLINE
| ID: mdl-37378840
ABSTRACT
PURPOSE:
To compare failure rates and maximum load capacity (Fmax) of six different computer-aided design/computer-aided manufacturing (CAD/CAM) retainers with those of the hand-bent five-stranded stainless steel twistflex retainer. MATERIALS ANDMETHODS:
Six groups (nâ¯= 8 per group) of commercially available CAD/CAM retainers (cobalt-chromium [CoCr], titanium grade 5 [Ti5], nickel-titanium [NiTi], zirconia [ZrO2], polyetheretherketone [PEEK], and gold) and twistflex retainers were tested for long-term sufficiency and for Fmax using a self-developed in vitro model. All retainer models underwent a simulated ageing process of about 15 years (1,200,000 chewing cycles with a force magnitude of 65â¯N at 45° followed by storage in water at 37⯰C for 30 days). If retainers did not debond or break during ageing, their Fmax was determined in a universal testing machine. Data were statistically analysed using Kruskal-Wallis and Mann-Whitney Utests.RESULTS:
Twistflex retainers did not fail (0/8) during ageing and had the highest Fmax (445â¯N⯱ 51â¯N). Ti5 retainers were the only CAD/CAM retainers that also did not fail (0/8) and had similar Fmax values (374â¯N⯱ 62â¯N). All other CAD/CAM retainers had higher failure rates during ageing and significantly lower Fmax values (pâ¯< 0.01; ZrO2 1/8, 168â¯N⯱ 52â¯N; gold 3/8, 130â¯N⯱ 52â¯N; NiTi 5/8, 162â¯N⯱ 132â¯N; CoCr 6/8, 122â¯N⯱ 100â¯N; PEEK 8/8, 65⯱ 0â¯N). Failure was due to breakage in the NiTi retainers and debonding in all other retainers.CONCLUSION:
Twistflex retainers remain the gold standard regarding biomechanical properties and long-term sufficiency. Of the CAD/CAM retainers tested, Ti5 retainers seem to be the most suitable alternative. In contrast, all other CAD/CAM retainers investigated in this study showed high failure rates and had significantly lower Fmax values.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Orofac Orthop
Asunto de la revista:
ODONTOLOGIA
/
ORTODONTIA
Año:
2023
Tipo del documento:
Article
País de afiliación:
Alemania