The bonded retainers are mainly used for the mandibular dental arch. This study aims to analyse the efficiency of three different types of fixed retainers, multistranded 0.0195-in wire, Australian wire and Starbond CoS laser sintering retainer, as well as the relapse rate for each type of retainer used over a period of two years. The sample consisted of 159 patients, of whom 55 patients (Group 1) had multistranded 0.0195-in wire, 53 patients (Group 2) Australian wire, and 51 patients (Group 3) laser-sintering retainers. 16 partial or complete detachments were recorded in the first year of the retention phase, of which 5 retainers from Group 1, 6 from Group 2 and 5 from Group 3, in the case of lasers-sintering retainers only total detachments were noticed, and 2 of the multistranded retainers suffered deformations. The results show that there are no statistically significant differences between the three types of retainers in the first year of retention period, but laser-sintering retainer had a statistically significant better evolution compared to multistranded retainer (p=0.018) after two years of retention. No statistically significant differences were found between the three types of retainers regarding the rate of relapse (10.9% for Group 1, 7.5% for Group 2 and 7.8% for Group 3). In the second year of the retention phase, the relapse rate did not present a statistically significant change from the first year, but it increased slightly in patients from Group 1 and it decreased slightly in patients from Group 3. No fixed retention system is perfect, everything has its drawbacks.