Table 1 Characteristics of included trials (n = 24)
From: The effects of fixed and removable orthodontic retainers: a systematic review
Study | Design | Participants (overall) | Intervention/comparison | Wear (part-time/full-time) | Follow-up period (mean ± SD) | Dental arch | Outcomes |
|---|---|---|---|---|---|---|---|
Al-Nimri et al. 2009 [25] | Prospective cohort study | n = 62 (18 M, 44 F) | - 0.036″ round stainless steel fixed retainer (canines only) (n = 31; mean age, 20.23 ± 3.8 years) - 0.015″ multistrand fixed retainer (n = 31; mean age, 19.97 ± 4.2 years) | 21.31 months 19.35 months | Mandibular anterior teeth | Plaque Index, Gingival Index, retainer failure, Oral Hygiene Index, Irregularity Index | |
Bazargani et al. 2012 [14] | RCT | n = 51 Overall mean age, 18.3 ± 1.3 years | - 0.0195″ multistrand fixed retainer with two-step bonded resin adhesive (n = 25) - 0.0195″ multistrand fixed retainer with non-resin adhesive (n = 26) | 24.4 ± 4.7 months | Mandibular anterior teeth | Retainer failure, calculus accumulation, discoloration around composite pads | |
Störmann and Ehmer 2002 [15] | RCT | n = 98 Overall age range, 13–17 years | - 0.0195″ Respond® fixed retainer (n = 30) - 0.0215″ Respond® fixed retainer (n = 36) - Prefabricated fixed retainer (canines only) (n = 32) | 24 months | Mandibular anterior teeth | Bleeding on probing, Plaque Index, failure rate, aesthetic problems, patient discomfort, Little’s irregularity index, occlusal discrepancies, intercanine width | |
Tynelius et al. 2014 [13] | RCT | n = 75 (30 M, 45 F) Overall mean age, 14.3 ± 1.5 years | - Vacuum-formed retainer in the maxilla and 0.7-mm spring hard wire fixed retainer in the mandibule (canines only) (n = 25) | Full-time for 2 days followed by part-time for 1 year. Every other night in the second year | 24 months | Maxillary and mandibular dentition | Cost-effectiveness and societal costs |
- Vacuum-formed retainer in the maxilla and interproximal enamel reduction in the mandibular anterior teeth (n = 25) | Full-time for 2 days followed by part-time for 1 year. Every other night in the second year | ||||||
- Prefabricated positioner (n = 25) | Part-time for 1 year, followed by every other night in the second year | ||||||
Torkan et al. 2014 [16] | RCT | n = 30 (10 M, 20 F) | - Fiber-reinforced resin composite fixed retainer (n = 15; mean age, 16.2 ± 1.9) - 0.0175″ Multistrand stainless steel fixed retainer (n = 15; mean age, 15.7 ± 2.1 years) | 6 months | Maxillary and mandibular anterior teeth | Plaque Index, Calculus Index, Gingival Index, bleeding on probing, width of periodontal ligament | |
Sfondrini et al. 2014 [17] | RCT | n = 87 (35 M, 52 F) Overall average age, 24 years (14–62 years) | - 0.5-mm silanized-treated glass fiber-reinforced composite resin fixed retainer (n = 40) - 0.0175″ multistrand stainless steel fixed retainer (n = 47) | 12 months | Mandibular anterior teeth | Bond adhesive failure | |
Ardeshna et al. 2011 [26] | Prospective cohort study | n = 56 (76 fixed retainers) | - 0.53- or 1.02-mm fiber-reinforced thermoplastic fixed retainer with polyethylene terephthalate glycol matrix resin | 24 months | Maxillary anterior teeth (2 retainers), mandibular anterior teeth (21 retainers, 6 of them were bonded to canines only) | Survival and failure rates | |
- 0.53- or 1.02-mm fiber-reinforced thermoplastic fixed retainer with polycarbonate matrix resin | Maxillary anterior teeth (14 retainers), mandibular anterior teeth (39 retainers, 5 of them were canines only) | ||||||
Salehi et al. 2013 [18] | RCT | n = 142 (59 M, 83 F) Overall age range, 14–28 years | - Polyethylene woven ribbon fixed retainer (n = 68; mean age, 18.1 ± 5.23 years) - 0.0175″ multistrand stainless steel fixed retainer (n = 74; mean age, 18.2 ± 4.81 years) | 18 months | Maxillary and mandibular anterior teeth | Survival and failure rates | |
Hichens et al. 2007 [12] | RCT | n = 355 (350 questionnaires completed at 6 months) (155 M, 242 F)a Overall mean age = 14–15 years | - Hawley retainer (n = 172) | Full-time for 3 months followed by part-time for 3 months | 6 months | Maxillary and mandibular dentition | Cost-effectiveness, patient satisfaction, failure rate, Little’s irregularity index |
- Vacuum-formed retainer (n = 183) | Full-time for 1 week, followed by part-time | ||||||
Bolla et al. 2012 [39] | RCT | n = 85 (29 M, 56 F) | - Glass fiber-reinforced fixed retainer (n = 40; mean age for M, 23.4 years; mean age for F, 20.2 years) - 0.0175″ multistrand stainless steel fixed retainer (n = 45; mean age for M, 24.1 years; mean age for F, 22.6 years) | 6 years | Maxillary 2-2 (14 retainers) and mandibular (34 retainers) anterior teeth Maxillary 2-2 (18 retainers) and mandibular (32 retainers) anterior teeth | Bond failure and breakage of retainers | |
Tacken et al. 2010 [31] | RCT | n = 274 (135 M, 139 F)a Overall mean age, 14 years | - Glass fiber-reinforced fixed retainer (500 unidirectional glass fibers) (n = 45; mean age, 14.8 years ± 1.3 years) - Glass fiber-reinforced fixed retainer (1000 unidirectional glass fibers) (n = 48; mean age, 14.6 years ± 2.7 years) - 0.0215″ coaxial fixed retainer (n = 91; mean age, 15 years ± 1.3 years) - Untreated control (n = 90) | 24 months | Maxillary 2-2 and mandibular anterior teeth | Failure rate, modified gingival index (MGI), bleeding on probing, Plaque Index (PI) | |
Bovali et al. 2014 [19] | RCT | n = 63 (28 M, 35 F) Overall age range: 12–38 years | - Direct bonding of 0.0215″ multistrand stainless steel fixed retainer (n = 31; mean age, 19.8 ± 6.5 years) - Indirect bonding of 0.0215″ multistrand stainless steel fixed retainer (n = 32; mean age, 17.2 ± 3.1 years) | 6 months | Mandibular anterior teeth | Failure rate, time to fit retainers | |
Pandis et al. 2013 [20] | RCT | n = 220 (60 M, 160 F) Overall median age, 16 (IQR 2) years Overall age range, 12–47 years | - 0.022″ multistrand stainless steel fixed retainer bonded with chemical-cured composite (n = 110; median age, 16 (IQR 2) years) - 0.022″ multistrand stainless steel fixed retainer bonded with light-cured composite (n = 110; median age, 16 (IQR 2) years) | Median follow-up period: 2.19 years Range, 0.003–3.64 years | Mandibular anterior teeth | Failure rate, adhesive remnant index scores | |
Sun et al. 2011 [11] | RCT | n = 111 Overall mean age, 14.7 years Overall age range, 12–17 years | - Hawley retainer (n = 56) | Full-time | 12 months | Maxillary and mandibular dentition | Survival and failure rates |
- Vacuum-formed retainer (n = 55) | Full-time | ||||||
Xu et al. 2011 [40] | RCT | n = 40 (16 M, 29 F) Overall mean age, 13–16 years | - Vacuum-formed retainer (n = 25) | Full-time | 12 months | Maxillary and mandibular dentition | Overjet, overbite, intercanine width, intermolar width, Little’s irregularity index, Calculus Index scores, failure rate |
- 0.0195″ multistrand stainless steel fixed retainer with Hawley retainer (n = 15) | Part-time | ||||||
Rose et al. 2002 [41] | RCT | n = 20 (12 M, 8 F) Overall mean age, 22.4 ± 9.7 years | - 1-mm polyethylene woven ribbon fixed retainer (n = 10) - 0.0175″ multistrand stainless steel fixed retainer (n = 10) | 24 months | Mandibular anterior teeth | Patient acceptance and preference, survival of retainers, amount of calculus, demineralisation, caries | |
Liu et al. 2010 [23] | RCT | n = 60 | - 0.75-mm fiber-reinforced composite fixed retainer (n = 30) - 0.9-mm multistrand stainless steel fixed retainer (n = 30) | 12 months | Mandibular anterior teeth | Bleeding index, pocket depth, failure rate | |
Taner et al. 2012 [27] | Prospective cohort study | n = 66 (14 M, 52 F) | - Direct bonding of 0.016″ × 0.022″ multistrand stainless steel dead soft wire fixed retainer (n = 32; mean age, 15.96 ± 3.21 years) - Indirect bonding of 0.016″ × 0.022″ multistrand stainless steel dead soft wire fixed retainer (n = 34; mean age, 19.44 ± 6.79 years) | 6 months | Mandibular anterior teeth | Failure rate | |
Artun et al. 1997 [28] | Prospective cohort study | n = 49 | - 0.032″ plain fixed retainer (canines only) (n = 11) | 3 years | Mandibular anterior teeth | Little’s irregularity index, failure rate, Plaque Index, Calculus Index, Gingival Index, probing attachment level | |
- 0.032″ spiral wire fixed retainer (canines only) (n = 13) | |||||||
- 0.0205″ spiral wire fixed retainer (n = 11) | |||||||
- Removable retainer (n = 14) | Unclear | ||||||
Scribante et al. 2011 [24] | RCT | n = 34 (9 M, 25 F) Overall mean age, 14.3 years | - 0.0175″ multistrand stainless steel fixed retainer - Polyethylene fiber-reinforced resin composite fixed retainer | 12 months | Mandibular anterior teeth | Failure rate, patient satisfaction of the aesthetic result | |
Zachrisson, 1977 [29] | Prospective cohort study | n = 43 (14–17 years) | - 0.032″ or 0.036″ blue Elgiloy fixed retainer bonded using a holding wire (canines only) (n = 22) | Mean, 15.7 months; Range, 12–30 months | Mandibular anterior teeth | Failure rate, calculus accumulation | |
- 0.032″ or 0.036″ blue Elgiloy fixed retainer bonded using a steel ligature (canines only) (n = 21) | |||||||
Heier et al. 1997 [30] | Prospective cohort study | n = 36 Overall mean age, 16.3 years Overall age range, 12.8–21.1 years | - 0.0175″ multistrand stainless steel fixed retainer (n = 22) | 6 months | Maxillary and mandibular anterior teeth Maxillary and mandibular dentition | Modified gingival index, bleeding on probing, Plaque Index, Calculus Index, gingival crevicular fluid flow | |
- Hawley retainer (n = 14) | Unclear | ||||||
Sobouti et al. 2016 [21] | RCT | n = 128 (60 M, 68 F) Overall mean age, 18 ± 3.6 years Overall age range, 13–25 years | - Fiber-reinforced composite fixed retainer (n = 42; mean age, 18.5 ± 3.6 years) - 0.0175″ flexible spiral wire fixed retainer (n = 41; mean age, 18.4 ± 3.7 years) - 0.0009″ dead soft twisted wires fixed retainer (n = 45; mean age, 17 ± 3.3 years) | 24 months | Mandibular anterior teeth | Survival and failure rates | |
O’Rouke et al. 2016 [22] | RCT | n = 82 (23 M, 59 F) | - Vacuum-formed retainer (n = 40, mean age: 16.95 ± 2.02 years) - 0.0175″ stainless steel coaxial fixed retainer (n = 42, Mean age: 18.47 ± 4.41 years) | Full-time for 6 months, followed by part-time for 6 months, then for every other night in the second year | 18 months | Mandibular dentition | Little’s irregularity index, intercanine width, intermolar width, arch length, failure rate |