The effects of fixed orthodontic retainers on periodontal health: A systematic review

Comparison of chairside rectangular chain retainers and multi-stranded conventional retainers: a randomized controlled trial

BACKGROUND

While retention appliances are widely used in orthodontics, there is still no evidence-based consensus regarding the optimal type of appliance or time of retention.

OBJECTIVES

To compare chairside rectangular chain retainers, which can be placed in one sitting, with conventional multi-stranded bonded retainers regarding their levels of stability, biological side effects, complications, and patient experiences.

TRIAL DESIGN

A single-centre, two-arm, parallel-group randomized controlled trial.

METHODS

In total, 48 patients were included in this single-centre, randomized controlled trial conducted in Varberg, Region Halland, Sweden. The patients were randomized to two groups: the chairside rectangular chain retainer group, using the Ortho FlexTech retainer (OFT); and the conventional retainer group, using the 0.0195 Penta One multi-stranded spiral wire (PeO). The primary outcome was Little´s irregularity index (LII) evaluated at debond (T0) and at 3 months (T3) and 12 months (T12). The secondary outcomes were inter-canine distance (ICD), plaque index (PI), calculus index (CI), bleeding on probing (BoP), and caries, evaluated at T0, T3, and T12, as well as patients' perceptions, evaluated at T3 and T12, and technical complications that were registered throughout the study period. The Mann-Whitney U-test was used for continuous variables for inter-group comparisons, and the Wilcoxon Signed Rank test was used for intra-group comparisons.

RESULTS

There were no statistically significant differences between the groups regarding LII, biological side effects, technical complications, or patients' experiences. However, there was a small but statistically significant difference between the groups regarding the maintenance of the ICD. Within the OFT group, there was a significant increase in CI, and within the PeO group, there was a significant increase in BoP.

CONCLUSIONS

In terms of clinical relevance, the chairside rectangular chain retainer and the conventional multi-stranded spiral wire provide similar outcomes with respect to the stability of alignment, biological side-effects, technical complications, and patients' experiences short-term.

TRIAL REGISTRATION

VGFOUreg-929962. Keywords: Orthodontic retainers; fixed retainers; retention; stability.

The oral microbiota and periodontal health in orthodontic patients

The oral microbiota develops within the first 2 years of childhood and becomes distinct from the parents by 4 years-of-age. The oral microbiota plays an important role in the overall health/symbiosis of the individual. Deviations from the state of symbiosis leads to dysbiosis and an increased risk of pathogenicity. Deviations can occur not only from daily life activities but also from orthodontic interventions. Orthodontic appliances are formed from a variety of biomaterials. Once inserted, they serve as a breeding ground for microbial attachment, not only from new surface areas and crevices but also from material physicochemical interactions different than in the symbiotic state. Individuals undergoing orthodontic treatment show, compared with untreated people, qualitative and quantitative differences in activity within the oral microbiota, induced by increased retention of supra- and subgingival microbial plaque throughout the treatment period. These changes are at the root of the main undesirable effects, such as gingivitis, white spot lesions (WSL), and more severe caries lesions. Notably, the oral microbiota profile in the first weeks of orthodontic intervention might be a valuable indicator to predict and identify higher-risk individuals with respect to periodontal health and caries risk within an otherwise healthy population. Antimicrobial coatings have been used to dissuade microbes from adhering to the biomaterial; however, they disrupt the host microbiota, and several bacterial strains have become resistant. Smart biomaterials that can reduce the antimicrobial load preventing microbial adhesion to orthodontic appliances have shown promising results, but their complexity has kept many solutions from reaching the clinic. 3D printing technology provides opportunities for complex chemical syntheses to be performed uniformly, reducing the cost of producing smart biomaterials giving hope that they may reach the clinic in the near future. The purpose of this review is to emphasize the importance of the oral microbiota during orthodontic therapy and to use innovative technologies to better maintain its healthy balance during surgical procedures.

Orthodontic retention: Rationale and periodontal implications

Post-treatment change in the form of true relapse and physiological and maturational effects is common following orthodontics. The unpredictable nature of these manifestations dictates a conservative, near-universal approach to retention. Both fixed and removable forms of retention are popular with the latter constrained by variable levels of adherence particularly in the medium- to long-term. Fixed retention may offer a more predictable means of preservation of orthodontic outcomes; however, this advantage is offset by the requirement for prolonged supervision and the potential for adverse changes including periodontal breakdown. Nevertheless, while examples of severe complications are common, a clear causal relationship between intact, passive retainers and periodontal issues does not appear to exist. Nevertheless, the importance of diligent maintenance and careful supervision during fixed retention, in particular, cannot be disregarded.

Influence of fixed orthodontic steel retainers on gingival health and recessions of mandibular anterior teeth in an intact periodontium - a randomized, clinical controlled trial

OBJECTIVE

Aim of this randomized clinical controlled trial was to evaluate the influence of fixed orthodontic steel retainers on gingival health and recessions of mandibular anterior teeth.

MATERIALS AND METHODS

After end of the orthodontic treatment, patients were randomly assigned into the test (fixed steel retainer) or control group (modified removable vacuum-formed retainer). Periodontal parameters (periodontal probing depth: PPD; recession: REC; bleeding on probing: BOP) as well as plaque and gingival index were assessed on mandibular anterior teeth directly before attaching/handing over the retainer (baseline: BL), 6 and 12 months after orthodontic treatment.

RESULTS

37 patients (test: n = 15, mean age: 16.1±4.2 years; control: n = 17, mean age: 17.1±5.4 years) completed the study. REC and PPD failed to show significant pairwise differences. The number of patients showing gingival health in the area of the mandibular anterior teeth (test: BL n = 10, 6 months n = 9, 12 months n = 11; control: BL n = 10, 6 months n = 16, 12 months n = 15) revealed a significant difference for the intra-group comparison between BL and 6 months in the control group (p = 0.043). The inter-group comparisons failed to show significant differences.

CONCLUSION

Young orthodontically treated patients with fixed steel retainers show in 73.3% healthy gingival conditions after one year which are comparable to the control group (88.2%). Gingival recessions were in a clinically non-relevant range at any time of the examination.

CLINICAL TRIAL NUMBER

DRKS00016710.

Metagenomic analysis of oral and intestinal microbiome of patients during the initial stage of orthodontic treatment

INTRODUCTION

This prospective study analyzed changes in the oral and intestinal microbiomes in patients before and after fixed orthodontic treatment, elucidating the impacts of fixed orthodontic treatment on patient health and metabolism.

METHODS

Metagenomic analysis was conducted on stool, dental plaque, and saliva samples from 10 fixed orthodontic patients. All the samples were sequenced with Illumina NovaSeq 6000 with a paired-end sequencing length of 150 bp. Identification of taxa in metagenomes and functional annotation of genes of the microbiota were performed using the data after quality control. Clinical periodontal parameters, including the gingiva index, plaque index, and pocket probing depth, were examined at each time point in triplicates. Patients also received a table to record their oral hygiene habits of brushing, flossing, and dessert consumption frequency over 1 month.

RESULTS

The brushing and flossing times per day of patients were significantly increased after treatment compared with baseline. The number of times a patient ate dessert daily was also fewer after treatment than at baseline. In addition, the plaque index decreased significantly, whereas the pH value of saliva, gingiva index, and pocket probing depth did not change. No significant differences were observed between the participants before and after orthodontic treatment regarding alpha-diversity analysis of the gut, dental plaque, or saliva microbiota. However, on closer analysis, periodontal disease-associated bacteria levels in the oral cavity remain elevated. Alterations in gut microbiota were also observed after orthodontic treatment.

CONCLUSIONS

The richness and diversity of the microbiome did not change significantly during the initial stage of fixed orthodontic treatment. However, the levels of periodontal disease-associated bacteria increased.

Periodontal indexes of two types of 3 x 3 retainers: 0.032-in SS V-loop versus 0.0215-in SS coaxial - a randomized crossover trial

OBJECTIVE

This randomized crossover trial evaluated periodontal indexes of two types of 3 x 3 retainers (a modified 0.032-in SS V-loop retainer and a conventional 0.0215-in SS coaxial wire retainer) after bonded for six months. Also, bonded failure rate, and a questionnaire about comfort, ease of cleaning and overall preference were recorded.

MATERIAL AND METHODS

15 patients were enrolled in this study who used both retainers for six months each, having a 15-day wash-out interval between each bonded retainer usage. The following periodontal index were recorded: Plaque Index (PI), Calculus Index (CI) and Gingival Index (GI). Patients answered a questionnaire to assess comfort, ease of cleaning and overall retainer-type preference. Rate of bonding failure was also evaluated.

RESULTS

V-Loop retainer showed higher PI (P<0.05) as compared to conventional 0.0215-in coaxial wire retainer. However, CI and GI presented no statistically significant differences between both types of retainers. The conventional 0.0215-in coaxial wire retainer was chosen as the most comfortable (p<0.05), although no statistically significant differences were found for all other questionnaire answers. Bonding failure events were more observed in the 3x3 V-Loop retainer (p<0.002), as compared to the conventional 0.0215-in coaxial retainer.

CONCLUSION

V-Loop retainer showed higher PI (p<0.05), higher bonding failure rate and less comfortable, as compared to conventional 0.0215-in coaxial wire.

Complications and treatment errors involving periodontal tissues related to orthodontic therapy

In this review, typical clinical complications involving periodontal tissues are illustrated that can be encountered in conjunction with orthodontic therapy (OT). Special considerations are given for various clinical scenarios, such as the patient presenting in periodontal health, with periodontitis, or with mucogingival conditions. While some of the complications are seen as common side effects of OT, other, more severe, problems that could have been avoided may be viewed as treatment errors. Recommendations are made on how to prevent these complications, based on the currently available evidence, on clinical practice guidelines, and on expert opinion. In conclusion, while there are several areas in which OT can have unwanted adverse effects on periodontal/mucogingival conditions, there is also great potential for synergies, offering opportunities for close cooperation between the two specialties (periodontics and orthodontics) for the benefit of patients affected by tooth malpositioning and/or periodontal or mucogingival problems.

Retention procedures for stabilising tooth position after treatment with orthodontic braces

BACKGROUND

Without a phase of retention after successful orthodontic treatment, teeth tend to 'relapse', that is, to return to their initial position. Retention is achieved by fitting fixed or removable retainers to provide stability to the teeth while avoiding damage to teeth and gums. Removable retainers can be worn full- or part-time. Retainers vary in shape, material, and the way they are made. Adjunctive procedures are sometimes used to try to improve retention, for example, reshaping teeth where they contact ('interproximal reduction'), or cutting fibres around teeth ('percision'). This review is an update of one originally published in 2004 and last updated in 2016.

OBJECTIVES

To evaluate the effects of different retainers and retention strategies used to stabilise tooth position after orthodontic braces.

SEARCH METHODS

An information specialist searched Cochrane Oral Health Trials Register, CENTRAL, MEDLINE, Embase and OpenGrey up to 27 April 2022 and used additional search methods to identify published, unpublished and ongoing studies.  SELECTION CRITERIA: Randomised controlled trials (RCTs) involving children and adults who had retainers fitted or adjunctive procedures undertaken to prevent relapse following orthodontic treatment with braces. We excluded studies with aligners.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened eligible studies, assessed risk of bias and extracted data. Outcomes were stability or relapse of tooth position, retainer failure (i.e. broken, detached, worn out, ill-fitting or lost), adverse effects on teeth and gums (i.e. plaque, gingival and bleeding indices), and participant satisfaction. We calculated mean differences (MD) for continuous data, risk ratios (RR) or risk differences (RD) for dichotomous data, and hazard ratios (HR) for survival data, all with 95% confidence intervals (CI). We conducted meta-analyses when similar studies reported outcomes at the same time point; otherwise results were reported as mean ranges. We prioritised reporting of Little's Irregularity Index (crookedness of anterior teeth) to measure relapse, judging the minimum important difference to be 1 mm.

MAIN RESULTS

We included 47 studies, with 4377 participants. The studies evaluated: removable versus fixed retainers (8 studies); different types of fixed retainers (22 studies) or bonding materials (3 studies); and different types of removable retainers (16 studies). Four studies evaluated more than one comparison. We judged 28 studies to have high risk of bias, 11 to have low risk, and eight studies as unclear.  We focused on 12-month follow-up.  The evidence is low or very low certainty. Most comparisons and outcomes were evaluated in only one study at high risk of bias, and most studies measured outcomes after less than a year. Removable versus fixed retainers Removable (part-time) versus fixed   One study reported that participants wearing clear plastic retainers part-time in the lower arch had more relapse than participants with multistrand fixed retainers, but the amount was not clinically significant (Little's Irregularity Index (LII) MD 0.92 mm, 95% CI 0.23 to 1.61; 56 participants). Removable retainers were more likely to cause discomfort (RR 12.22; 95% CI 1.69 to 88.52; 57 participants), but were associated with less retainer failure (RR 0.44, 95% CI 0.20 to 0.98; 57 participants) and better periodontal health (Gingival Index (GI) MD -0.34, 95% CI -0.66 to -0.02; 59 participants). Removable (full-time) versus fixed   One study reported that removable clear plastic retainers worn full-time in the lower arch did not provide any clinically significant benefit for tooth stability over fixed retainers (LII MD 0.60 mm, 95% CI 0.17 to 1.03; 84 participants). Participants with clear plastic retainers had better periodontal health (gingival bleeding RR 0.53, 95% CI 0.31 to 0.88; 84 participants), but higher risk of retainer failure (RR 3.42, 95% CI 1.38 to 8.47; 77 participants). The study found no difference between retainers for caries.  Different types of fixed retainers Computer-aided design/computer-aided manufacturing (CAD/CAM) nitinol versus conventional/analogue multistrand One study reported that CAD/CAM nitinol fixed retainers were better for tooth stability, but the difference was not clinically significant (LII MD -0.46 mm, 95% CI -0.72 to -0.21; 66 participants). There was no evidence of a difference between retainers for periodontal health (GI MD 0.00, 95% CI -0.16 to 0.16; 2 studies, 107 participants), or retainer survival (RR 1.29, 95% CI 0.67 to 2.49; 1 study, 41 participants). Fibre-reinforced composite versus conventional multistrand/spiral wire  One study reported that fibre-reinforced composite fixed retainers provided better stability than multistrand retainers, but this was not of a clinically significant amount (LII MD -0.70 mm, 95% CI -1.17 to -0.23; 52 participants). The fibre-reinforced retainers had better patient satisfaction with aesthetics (MD 1.49 cm on a visual analogue scale, 95% CI 0.76 to 2.22; 1 study, 32 participants), and similar retainer survival rates (RR 1.01, 95% CI 0.84 to 1.21; 7 studies; 1337 participants) at 12 months. However, failures occurred earlier (MD -1.48 months, 95% CI -1.88 to -1.08; 2 studies, 103 participants; 24-month follow-up) and more gingival inflammation at six months, though bleeding on probing (BoP) was similar (GI MD 0.59, 95% CI 0.13 to 1.05; BoP MD 0.33, 95% CI -0.13 to 0.79; 1 study, 40 participants). Different types of removable retainers Clear plastic versus Hawley When worn in the lower arch for six months full-time and six months part-time, clear plastic provided similar stability to Hawley retainers (LII MD 0.01 mm, 95% CI -0.65 to 0.67; 1 study, 30 participants). Hawley retainers had lower risk of failure (RR 0.60, 95% CI 0.43 to 0.83; 1 study, 111 participants), but were less comfortable at six months (VAS MD -1.86 cm, 95% CI -2.19 to -1.53; 1 study, 86 participants). Part-time versus full-time wear of Hawley There was no evidence of a difference in stability between part-time and full-time use of Hawley retainers (MD 0.20 mm, 95% CI -0.28 to 0.68; 1 study, 52 participants).

AUTHORS' CONCLUSIONS

The evidence is low to very low certainty, so we cannot draw firm conclusions about any one approach to retention over another. More high-quality studies are needed that measure tooth stability over at least two years, and measure how long retainers last, patient satisfaction and negative side effects from wearing retainers, such as tooth decay and gum disease.

Comparison between round multi-strand wire and rectangular wire bonded retainers: a randomized clinical trial

OBJECTIVE

The primary objective was to compare round multi-strand wire and Ortho-Flex-Tech™ rectangular wire retainers in terms of gingival health. The secondary objectives were to assess plaque/calculus accumulation, and to determine the effectiveness of these retainers in maintaining tooth alignment and their failure rate.

MATERIAL AND METHODS

This single-center study was a two-arm parallel randomized clinical trial and was conducted at the Orthodontic clinics in Dental Teaching Center/Jordan University of Science and Technology. Sixty patients, with bonded retention for the mandibular anterior segment after fixed orthodontic treatment, were randomly selected. The sample comprised Caucasian patients with mild to moderate pretreatment crowding in the mandibular anterior region, Class I relationship, treated without extraction of mandibular anterior tooth. In addition, only patients presenting normal overjet and overbite after treatment were included.

INTERVENTION

One group received round multi-strand wire retainer (30 patients, average age: 19.7 ± 3.8 years), while the other group received Ortho-Flex-Tech™ retainer (30 patients; average age: 19.3 ± 3.2 years). In both groups, the retainers were bonded to all mandibular anterior teeth from canine to canine. All patients were recalled one year after bracket debonding. Randomization sequence was created using Excel 2010, with a 1:1 allocation, using random block size 4. The allocation sequence was concealed in sequentially numbered, opaque and sealed envelopes. Only participants were blinded to the type of bonded retainer used. The primary outcome was to compare the gingival condition between the two groups. The secondary outcomes were to assess plaque/calculus indices, irregularity index of the mandibular anterior teeth and retainers' failure rate. Comparisons were conducted using Mann-Whitney U test or chi-square test. Statistical significance was predetermined at the p≤ 0.05 level for all tests.

RESULTS

Complete data were collected for 46 patients (round multi-strand wire retainer group, n=24 patients; rectangular Ortho-Flex-Tech™ retainer group, n=22 patients). No significant differences were found in the gingival health parameters between the two groups (p>0.05). Ortho-Flex-Tech™ retainers maintained the alignment of mandibular anterior teeth more than multi-strand retainer (p<0.05). No significant difference was found in the failure rate between the two groups (p>0.05).

CONCLUSIONS

Gingival health parameters and failure rate were not different in both groups. However, Ortho-Flex-Tech™ retainers were more efficient to retain the mandibular incisors than the multi-strand retainers; nevertheless, the difference was not clinically significant.

Direct 3D-Printed Orthodontic Retainers. A Systematic Review

Three-dimensional (3D) printing technology has shed light on many fields in medicine and dentistry, including orthodontics. Direct 3D-printed prosthetics, implants or surgical devices are well-documented. The fabrication of orthodontic retainers using CAD technology and additive manufacturing is an emerging trend but the available data are scarce. The research approach of the present review included keywords in Medline, Scopus, Cochrane Library and Google Scholar up to December 2022. The searching process concluded with five studies eligible for our project. Three of them investigated directly 3D-printed clear retainers in vitro. The other two studies investigated directly 3D-printed fixed retainers. Among them, one study was in vitro and the second was a prospective clinical trial. Directly 3D-printed retainers can be evolved over time as a good alternative to all the conventional materials for retention. Devices that are 3D-printed are more time and cost efficient, offer more comfortable procedures for both practitioners and patients and the materials used in additive manufacturing can solve aesthetic problems, periodontal issues or problems with the interference of these materials with magnetic resonance imaging (MRI). More well-designed prospective clinical trials are necessary for more evaluable results.

Effects of fixed retainers on gingival recession - a 10-year retrospective study

OBJECTIVE

The aetiology of gingival recessions is not fully understood, and no evidence has yet emerged of a single predisposing factor that instigates this apical shift of the gingival margin. Nonetheless, both fixed retainers and orthodontic treatment have been cited as potential risk factors. The aim of this study was to assess the effects of orthodontic treatment and orthodontic fixed retainers on gingival recessions.

SUBJECTS AND METHODS

In total, 105 patients at the Department of Orthodontics at the University of Gothenburg who had undergone orthodontic treatment between 1995 - 2003 were included in this study. Intraoral photographs of the anterior segment and study casts acquired at baseline (pre-treatment), post-treatment and at the 10-year follow-up were used as recorded measurements of gingival recession and orthodontic treatment. At the 10-year follow-up, the patients were divided into two groups based on: long-term (10 years) presence of a fixed retainer [orthodontic treatment and retainer (OR) group; N = 76]; and short-term (<5 years) presence of a fixed retainer [orthodontic treatment (O) group; N = 57]. These groups were compared to a control group (C) of untreated subjects (N = 29).

RESULTS

In the anterior segment, gingival recessions were not present at baseline and post-treatment between the two orthodontically treated groups. At the 10-year follow-up, there was no statistically significant difference between the two orthodontically treated groups and the controls.

CONCLUSIONS

Orthodontic treatment per se does not increase the risk for gingival recessions, nor does the use of fixed retainers following orthodontic treatment.

FIBER REINFORCED COMPOSITE RETAINERS MAY BE AS EFFECTIVE AS MULTISTRANDED STAINLESS-STEEL WIRES IN FAILURE RATES AND MINIMAL ADVERSE EFFECT, BUT SUPERIOR IN TERMS OF RELAPSE AND PATIENT SATISFACTION

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Liu S, Silikas N, Ei-Angbawi A. Analysis of the effectiveness of the fiber-reinforced composite lingual retainer: A systematic review and meta-analysis. Am J Orthod Dentofacial Orthop. 2022 Aug 26:S0889-5406(22)00,432-2. doi: 10.1016/j.ajodo.2022.07.003. Epub ahead of print. PMID: 36,031,511.

SOURCE OF FUNDING

Not reported.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data.

Orthodontic Retainers-A Critical Review

The achievement of aesthetic, functional occlusion should not mark the end of the orthodontic intervention. To prevent relapse, retention needs advance planning, and may vary in duration. This review aims to present and comment on the available means of retention. The ever-popular, passive Hawley-like removable appliances are credible in maintaining the desired occlusion. Modifications are the removable appliance Wrap Around, having the labial archwire extending to the premolars; the translucent retainer, Astics, a unique aesthetic Hawley-type device; and the reinforced removable retainer, which features a metallic grid reinforcing the acrylic base. Vacuum-formed retainers are easy to fabricate and are readily prescribed. By contrast, fixed retainers are made of orthodontic wire and composite resin bonded on the lingual or palatal surfaces of the anterior teeth. Patient-related variables need evaluation to select the appropriate retainer, while patients ought to realize the importance of retention and comply with offered guidance. Overall, the orthodontist is responsible for keeping the patient informed on the properties and the duration of retention, even before starting active orthodontic treatment.

Orthodontic Retainers-A Critical Review

The achievement of aesthetic, functional occlusion should not mark the end of the orthodontic intervention. To prevent relapse, retention needs advance planning, and may vary in duration. This review aims to present and comment on the available means of retention. The ever-popular, passive Hawley-like removable appliances are credible in maintaining the desired occlusion. Modifications are the removable appliance Wrap Around, having the labial archwire extending to the premolars; the translucent retainer, Astics, a unique aesthetic Hawley-type device; and the reinforced removable retainer, which features a metallic grid reinforcing the acrylic base. Vacuum-formed retainers are easy to fabricate and are readily prescribed. By contrast, fixed retainers are made of orthodontic wire and composite resin bonded on the lingual or palatal surfaces of the anterior teeth. Patient-related variables need evaluation to select the appropriate retainer, while patients ought to realize the importance of retention and comply with offered guidance. Overall, the orthodontist is responsible for keeping the patient informed on the properties and the duration of retention, even before starting active orthodontic treatment.

Comparison of periodontal status and failure rates with different retainer bonding methods and adhesives: a randomized clinical trial

OBJECTIVES

This single-center, randomized clinical trial evaluated and compared retainer bonding among different methods and adhesives in terms of periodontal status and failure rates.

MATERIALS AND METHODS

A total of 100 patients from the orthodontic department of Pamukkale University were randomly assigned to the following 4 groups: group 1, direct bonding (DB) with two-step adhesive; group 2, DB with one-step adhesive; group 3, indirect bonding (IDB) with two-step adhesive; and group 4, IDB with one-step adhesive. Eligibility criteria included good finishing results and oral hygiene, no periodontal or systemic problems, and no missing anterior teeth or restorations. Randomization was carried out using computer-generated random numbers with allocation concealment by opaque, sealed envelopes. The main outcomes were plaque index (PI), gingival index (GI), and calculus index (CI) recorded at bonding, 6 months (T1), and 12 months (T2) after bonding. A secondary outcome was failure rate. The periodontal outcome assessor was blinded. Data were analyzed using the Mann-Whitney U-test, Kruskal-Wallis test, and chi-square test.

RESULTS

PI and GI increased with time in all study groups, but there were no significant differences among groups at any time point. A small amount of calculus was observed in all study groups, with the increase in CI for group 3 significantly greater at the T2-T1 time interval (P < .05). There were no significant differences between groups for 12-month failure rates.

CONCLUSIONS

The one-step retainer adhesive was similar in terms of periodontal status and failure rate. Therefore, a one-step adhesive can be used during bonding, regardless of technique.

Comparison of multistranded wire and fiber-reinforced composite retainers effects on periodontium: A randomized clinical trial

INTRODUCTION

Fixed orthodontic retainers are very important for treatment stability; however, adverse effects on the health of periodontium can be caused as a result of deposition of plaque and calculus.

OBJECTIVES

To compare and determine the effects of two mandibular fixed lingual retainers on the periodontal status, and to test the null hypothesis that there would be no significant difference on the periodontium health between the patients using fiber-reinforced composite (FRC) or multistranded wire (MSW) fixed retainers.

METHODS

A total of 60 subjects were recruited, out of which 6 were excluded and 2 dropped out during the study. Hence, 52 subjects with mean age of 21.5 ± 3.6 years were included in the study. The sample was composed by 8 males (15.4%) and 44 females (84.6%). The participants were randomly divided into two groups: Group 1 received fiber-reinforced composite retainer, while Group 2 received multistranded wire retainer. After insertion, plaque index, calculus index, gingival index and bleeding on probing were compared, after three months (T1), six months (T2), nine months (T3) and twelve months (T4), using Mann-Whitney test with p-value ≤ 0.05 as significant.

RESULTS

It could be seen that the health of periodontium deteriorated with the passage of time from T1 to T4 in both group of retainers. However, no statistically significant differences were found between the two groups (p> 0.05).

CONCLUSION

The results of the study indicate that there was no significant difference on the health of periodontium between the patients with FRC and MSW fixed retainers, hence, the null hypothesis was accepted.

Analysis of the effectiveness of the fiber-reinforced composite lingual retainer: A systematic review and meta-analysis

INTRODUCTION

Orthodontic fixed retainers are preferred as they depend less on patient compliance. Recently, researchers tried to use fiber-reinforced composite (FRC) to replace the multistranded stainless-steel wire (MSW) of the fixed retainers to enhance the mechanical properties and esthetics. This systematic review aimed to analyze the effectiveness of the FRC retainers.

METHODS

We searched the electronic databases (May 1, 2021), including Medline, the Cochrane Library, EMBASE, PubMed, Web of Science, and CINAHL. We applied no language or date restrictions in the searches of the databases. Only randomized controlled trials (RCTs) and prospective clinical controlled trials were included. The revised Cochrane risk of bias tool for randomized trials and risk of bias in nonrandomized studies of interventions were used to evaluate the risk of bias in RCTs and non-RCTs, respectively. The outcomes were pooled using Review Manager 5.4. The primary outcome of this review was teeth relapse, and the secondary outcomes were bonded retainer failure rate, adverse effect on oral health, and patient's satisfaction.

RESULTS

Eleven out of 99 studies, which included 873 participants, were used in this review, with the follow-up ranging from 6 months to 6 years. Ten studies compared the FRC retainers with MSW retainers, and 1 study compared FRC retainers with a different fiber material. Ten studies were RCT, and 1 was non-RCT. There was 0.39 less relapse with the FRC retainers than with MSW retainers (mean difference, -0.39; 95% confidence interval [CI], -0.41 to -0.37; P <0.00001). There was no statistically significant difference in the failure rate between the FRC and MSW with the whole retainer as an outcome unit risk ratio of 1.72 (95% CI, 0.57-5.14; P = 0.33) or with the teeth an as outcome unit risk ratio of 0.85 (95% CI, 0.47-1.52; P = 0.58). There was insufficient evidence to conduct the meta-analysis of the adverse effect on oral health and patient satisfaction.

CONCLUSIONS

Low-quality evidence is available to suggest that the effectiveness of the FRC is comparable to the MSW with no significant difference in the failure rate. However, we have very low certainty on these results. It is worth conducting future robust clinical studies to assess the effectiveness of FRC retainers with long follow-up.

Orthodontic Fixed Retainer and Unwanted Movements of Lower Anterior Teeth: A Case Report

The use of fixed retainers at the end of an orthodontic treatment has become a standard practice. Nonetheless, orthodontic relapse can still occur, requiring retreatment in the most severe cases. This case report describes a patient with a mandibular canine to canine fixed retainer presenting uncontrolled torque on all lower anterior teeth, probably due to tongue thrust and/or activation of the wire. Multibracket orthodontic treatment was performed, and an orthodontic lingual sectional was used to control (reposition) the root movement of the lower right cuspid. This case highlights the need for clinicians and patients to be aware of the potential problems associated with bonded retainers. In addition, patients with an orthodontic fixed retainer need regular short-term observation by an orthodontist in order to detect any adverse movements and long-term control by a general dentist.

Application of antibacterial nanoparticles in orthodontic materials

During the orthodontic process, increased microbial colonization and dental plaque formation on the orthodontic appliances and auxiliaries are major complications, causing oral infectious diseases, such as dental caries and periodontal diseases. To reduce plaque accumulation, antimicrobial materials are increasingly being investigated and applied to orthodontic appliances and auxiliaries by various methods. Through the development of nanotechnology, nanoparticles (NPs) have been reported to exhibit excellent antibacterial properties and have been applied in orthodontic materials to decrease dental plaque accumulation. In this review, we present the current development, antibacterial mechanisms, biocompatibility, and application of antibacterial NPs in orthodontic materials.

Treatment of stage IV periodontitis: The EFP S3 level clinical practice guideline

BACKGROUND

The recently published clinical practice guideline (CPG) for the treatment of periodontitis in stages I-III provided evidence-based recommendations for the treatment of periodontitis patients, defined according to the 2018 classification. Stage IV periodontitis shares the severity and complexity characteristics of stage III periodontitis, but includes the anatomical and functional sequelae of tooth and periodontal attachment loss (tooth flaring and drifting, bite collapse, etc.), which require additional interventions following completion of active periodontal therapy.

AIM

To develop an S3 Level CPG for the treatment of stage IV periodontitis, focusing on the implementation of inter-disciplinary treatment approaches required to treat/rehabilitate patients following associated sequelae and tooth loss.

MATERIALS AND METHODS

This S3 Level CPG was developed by the European Federation of Periodontology (EFP), following methodological guidance from the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process. A rigorous and transparent process included synthesis of relevant research in 13 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, the formulation of specific recommendations and a structured consensus process with leading experts and a broad base of stakeholders.

RESULTS

The S3 Level CPG for the treatment of stage IV periodontitis culminated in recommendations for different interventions, including orthodontic tooth movement, tooth splinting, occlusal adjustment, tooth- or implant-supported fixed or removable dental prostheses and supportive periodontal care. Prior to treatment planning, it is critically important to undertake a definitive and comprehensive diagnosis and case evaluation, obtain relevant patient information, and engage in frequent re-evaluations during and after treatment. The periodontal component of therapy should follow the CPG for the treatment of periodontitis in stages I-III.

CONCLUSIONS

The present S3 Level CPG informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to treat patients with stage IV periodontitis and to maintain a healthy dentition over lifetime, according to the available evidence at the time of publication.

Patient-Reported Outcome Measures on Oral Hygiene, Periodontal Health, and Treatment Satisfaction of Orthodontic Retention Patients up to Ten Years after Treatment-A Cross-Sectional Study

Background: This cross-sectional study evaluated patient-reported outcome measures (PROMs) on (1) oral hygiene, (2) periodontal health, (3) retainer failure, (4) orthodontic treatment satisfaction, and (5) outcome satisfaction in orthodontic retention patients. The purpose of the study was to evaluate whether orthodontic retention treatment is associated with patient-reported outcome measures on oral hygiene, periodontal health, and treatment satisfaction. Methods: A ten-item questionnaire on the five PROMs was conducted among 211 consecutive retention patients up to ten years following orthodontic treatment. Linear regression models were computed to detect possible associations between the PROMs and retention treatment or patient characteristics. Results: The presence of a fixed lingual retainer was not associated with the reduced ability to perform oral hygiene, self-perceived periodontal health, or orthodontic outcome satisfaction. Older patients were more content with the orthodontic treatment result (p < 0.05). Patients with fixed lingual retainers in the mandible were less satisfied with the course of orthodontic treatment (p < 0.05). Smokers more often reported gingival bleeding (p < 0.05). Females reported increased gingival recessions (p < 0.05) and perceived their teeth as longer than before treatment (p < 0.05). Longer orthodontic treatment duration corresponded to retainer failure (p < 0.05). Conclusions: In general, long-term orthodontic retention patients were satisfied with orthodontic treatment. These patients reported the satisfactory ability to perform adequate oral hygiene and periodontal health, and they communicated a high degree of treatment and outcome contentment. However, patients with a retainer in the mandible were less satisfied with orthodontic treatment.

Comparative assessment of relapse and failure between CAD/CAM stainless steel and standard stainless steel fixed retainers in orthodontic retention patients

OBJECTIVES

To compare relapse and failure rates of computer-aided design/computer-aided manufacturing (CAD/CAM) and standard fixed retainers.

MATERIALS AND METHODS

This single-center, single-blinded, prospective randomized clinical trial included 46 patients who completed active orthodontic treatment and complied with retention visits. The patients were randomly assigned to three groups: CAD/CAM group with multistranded stainless steel wires (CAD/CAM, n = 16), Lab group with the same multistranded wires (lab, n = 16), and control group with stainless steel Ortho-FlexTech wires (traditional, n = 14). Intraoral scans were obtained at placement of fixed retainers (T1), 3-month visit (T2), and 6-month visit (T3) and measured for intercanine width and Little's Irregularity Index. Failures were recorded.

RESULTS

The CAD/CAM group experienced less intercanine width decrease than the traditional group at 3 months (mean difference, 0.83 ± 0.16 mm; 95% confidence interval [CI], 0.44-1.22; P < .001) and 6 months (mean difference, 1.23 ± 0.40 mm; 95% CI, 0.19-2.27; P < .05). The CAD/CAM group experienced less increase in Little's Irregularity Index compared with the lab group within 3 months (mean difference, 0.81 ± 0.27 mm; 95% CI, 0.12-1.49; P < .05). Failures from greatest to least were experienced by the lab group (43.8%), the CAD/CAM group (25%), and the traditional group (14.3%).

CONCLUSIONS

Within 6 months of bonding fixed retainers, CAD/CAM fixed retainers showed less relapse than lab-based and traditional chairside retainers and less failures than lab-based retainers.

Periodontal status in long-term orthodontic retention patients up to 10 years after treatment - a cross-sectional study

OBJECTIVE

To assess periodontal status in long-term orthodontic retention patients and investigate possible risk indicators.

MATERIALS AND METHODS

Plaque index (PI), gingival index (GI), probing pocket depth (PPD), gingival recessions (GR) and calculus were recorded in 211 patients with or without fixed retainers.

RESULTS

Periodontal parameters were within the limits of clinically healthy periodontium. The use of fixed retainers was associated with higher PI in the maxilla (ß = 1.10 [0.37]; p <.05). Older age was associated with higher PI in the mandible (ß = 0.27 [0.11]; p <.05). Smoking was associated with gingival bleeding on both palatal (ß = 0.63 [0.16]; p < .01) and labial sides in the maxilla (ß = 0.46 [0.20]; p <.05). Smoking was also associated with increased prevalence of GR in the mandible (ß = 0.24 [0.07]; p <.01), while use of snuff had similar effect on the labial side in the maxilla (ß = 0.35 [0.08]; p <.01). Higher age (ß = 0.05 [0.02]; p <.05) and the presence of a retainer (ß = 0.23 [0.07]; p < .05) were associated with calculus accumulation on the lingual side in the mandible.

CONCLUSION

The present observational study suggest that long-term fixed retainers alone have no detrimental effect on the periodontium. Additional factors may increase the risk of plaque deposits and increased probing pocket depths. Further prosepective studies are needed to confirm the present outcome.

Is YouTube an adequate patient resource about orthodontic retention? A cross-sectional analysis of content and quality

INTRODUCTION

The study aimed to evaluate the content and quality of information offered by YouTube for patients seeking information related to orthodontic retainers.

METHODS

YouTube was searched using the keyword "orthodontic retainers" from Google Trends. From the first 120 results, 97 videos were selected to be analyzed. Videos were rated for quality by video information and quality index (VIQI) and the global quality scale (GQS). Videos were classified as low- and high-content groups using a 10-point score considering several retainer-related topics. Mann-Whitney U tests, chi-square tests, and Pearson correlation coefficients were used for statistical evaluations.

RESULTS

Most YouTube videos were uploaded by dentists/specialists (62.9%). We classified 12 videos as high content and 85 as low content. Instructions on the use of the orthodontic retainer was the most commonly covered topic (42.3%), followed by the effect on oral hygiene (38.1%), definition (37.1%), procedure of preparing orthodontic retainers (33.0%), and procedure of positioning (30.9%). A lower percentage of videos (6.2%) mentioned soft tissue irritation. The high-content video group had a significantly higher median value of GQS score and VIQI (P <0.001). The correlation between GQS and VIQI was strong (r = 0.698; P <0.01).

CONCLUSIONS

The content of YouTube videos for orthodontic retainers could not be considered as an adequate source of information for patients on orthodontic retainers. Most videos included instructions on the use of orthodontic retainers, but fewer videos mentioned the effect on speech performance and soft tissue irritations.

A comparative assessment of failures and periodontal health between 2 mandibular lingual retainers in orthodontic patients. A 2-year follow-up, single practice-based randomized trial

INTRODUCTION

The objective of this study was to compare the survival rates and periodontal health in patients with 3-strand round twisted (RT) vs 8-strand rectangular braided (RB) fixed retainers bonded to all 6 anterior teeth in the mandible.

METHODS

A total of 133 patients completing orthodontic treatment (median age, 24.6 years; 25th percentile, 17.2 years; 75th percentile, 32.4 years; minimum, 15.1 years; maximum, 49.8 years) were randomly allocated in a 1:1 ratio to receive either an RT or RB wire retainer. Inclusion criteria were all mandibular permanent incisors and canines present, no active caries, no restorations, no fractures on the mandibular incisors and canines, no periodontal disease. Patients with poor oral hygiene before debonding were excluded from the trial. The primary outcome was any first-time retainer failure. Secondary outcomes were periodontal index, bleeding on probing, plaque index, gingival index, and probing depth. Randomization was accomplished with random permuted blocks of size 4, 6, or 8 with allocation concealed in sequentially numbered, opaque, sealed envelopes. Blinding was not possible in this trial. Patients were evaluated at baseline, 3, 6, 12, 18, and 24 months after placement of the retainer. Retainer survival was assessed using Cox regression. Periodontal parameters were reported at each time point and generalised estimating equations were used to assess the effect of treatment, time, tooth and treatment X time interaction on the indices.

RESULTS

Baseline characteristics were similar between groups; in 1 patient, the intervention was discontinued. During 2-year follow-up 37 of 66 (56.1%, RT group) and 32 of 66 (48.5%, RB group) retainers failed at least once (log-rank test, P = 0.55). The adjusted hazard ratio was 0.69 (95% confidence interval, 0.42-1.12; P = 0.13). Neither age nor gender was a predictor of failure. All periodontal parameters (periodontal index, bleeding on probing, plaque index, gingival index, and pocket depth) were comparable between groups and remained relatively stable during follow-up.

CONCLUSIONS

The overall risk for first-time failure was high and amounted to 52.3% (56.1% in the RT group and 48.5% in the RB group). There was no difference in terms of survival or periodontal health between the examined retainers.

What causes failure of fixed orthodontic retention? - systematic review and meta-analysis of clinical studies

BACKGROUND

Orthodontic retention aims to maintain optimal teeth positions after active treatment. The stability is affected by numerous factors, including patients' individual features, thus retention should be adjusted in the most optimal way. Bonding a retainer makes retention less dependent on patient's compliance.

QUESTIONS ARISE

What wire or fiber splint type provides the best treatment stability? What materials should be used to bond the wire or fiber splint? Should be the bonding procedure be direct or indirect? The aim of the study is to assess and synthesize available controlled trials investigating failures of fixed retainers.

METHODS

Literature searches of free text and MeSH terms were performed in Scopus, Web of Science, Embase and PubMed Central in order to find studies, referring to failures of fixed retention (12th February 2021). The keywords were: ("orthodontic retainers AND failure AND wire"). The framework of this systematic review according to PICO was: Population: orthodontic patients; Intervention: fixed orthodontic retainer bonding; Comparison: Different protocols of fixed orthodontic retention applied; Outcomes: failure rate, survival rate. Three different specific scales from the Cochrane Collaboration Handbook were used, according to each study type. Additionally, a meta-analysis was conducted to compare the effectiveness of retention using fiber reinforced composite and multistranded steel wire.

RESULTS

The search identified 177 potential articles: 114 from PubMed, 41 from Scopus, 20 from Web of Science and 2 from Embase. After excluding studies inconsistent with selection criteria, 21 studies were included and subjected to qualitative analysis. The main outcome investigated was failure rate. This systematic review has some potential limitations due to the heterogeneity of design between included studies.

CONCLUSIONS

No retainer is proved to guarantee a perfect stability of dental alignment. The retainer should be bonded to all adherent teeth, preferably with additional use of bonding resin. No wire or fiber splint present superior characteristics concerning failure rate. Fiber reinforced composite retention is more sensitive to operator skills, and with imperfect bonding technique, failure rate is much higher. During the first 6 months after bonding retainer the patient should be under frequent control. The study protocol was registered in PROSPERO database with the number CRD42021233406.

Effect of orthodontic therapy in periodontitis and non-periodontitis patients: a systematic review with meta-analysis

AIM

To answer these PICO questions: #1: In adult patients with malocclusion, what are the effects of orthodontic tooth movement (OTM) on clinical attachment level (CAL) changes in treated periodontitis patients with a healthy but reduced periodontium compared to non-periodontitis patients? #2: In adult patients with treated periodontitis and malocclusion, which is the efficacy of skeletal anchorage devices compared to conventional systems in terms of orthodontic treatment outcomes?

MATERIAL AND METHODS

Seven databases were searched until June 2020 looking for randomized, non-randomized trials and case series. Mean effects (ME) and 95% confidence intervals (CIs) were calculated.

RESULTS

Twenty-six studies with high risk of bias were included. PICO#1: In 26 patients without periodontitis and in 69 treated periodontitis patients, minimal changes in periodontal outcomes were reported after orthodontic therapy (p>0.05). A significant CAL gain (mm) (ME=3.523; 95% CI [2.353; 4.693]; p<0.001) was observed in 214 patients when periodontal outcomes were retrieved before a combined periodontal and orthodontic therapy. PICO#2: Orthodontic variables were scarcely reported and objective assessment of the results on orthodontic therapy were missing.

CONCLUSIONS

Based on a small number of low-quality studies, in non-periodontitis and in stable treated periodontitis patients, OTM had no significant impact on periodontal outcomes.

How do general dental practitioners perceive and deal with orthodontic bonded retainers?

INTRODUCTION

Long-term follow-up and management of orthodontic bonded retainers require a strong collaboration between orthodontists and general dental practitioners (GDPs). This study aimed to evaluate if Eastern French GDPs were aware of bonded retainers' complications and side effects and if they were willing to take part in their long-term follow-up.

METHODS

Two-hundred and eighteen randomly selected GDPs were invited to answer an online questionnaire. The initial sections covered their experience and management with bonded retainers. In the final sections, GDPs were asked their opinion on the responsibility for long-term follow-up of patients wearing fixed retainers and on the mutual communication between orthodontists and GDPs. Statistical analysis involved descriptive statistics and Fisher exact tests.

RESULTS

Response rate was 32.6% (n = 71). The vast majority of GDPs were familiar with loose retainers, but only 45.2% were willing to repair them. Respondents offering orthodontic services on a regular basis were more likely to insert retainers and repair loose or broken retainers (P < 0.001). Approximately 18.6% of GDPs were aware of third-order side effects encountered with unintentionally active retainers bonded to all 6 anterior teeth. For 88.8% of GDPs, permanent retention was justified, whereas 90% of the dentists refused to be responsible for long-term supervision of fixed retainers. In addition, 67.1% were interested in further training on orthodontic retention, and 92.9% would appreciate clinical guidelines.

CONCLUSIONS

Knowledge about the harmful side effects of bonded retainers was evaluated as insufficient among surveyed GDPs. Long-term follow-up of patients wearing bonded retainers raises issues that should be addressed globally by enhancing mutual communication, practitioners' education, and patients' involvement.

Evaluation of antimicrobial properties of nano-silver particles used in orthodontics fixed retainer composites: an experimental in-vitro study

Background. The present study evaluated the antimicrobial efficacy of composite resins containing nano-silver (NAg) particles used in fixed orthodontic retainers. Methods. Nano-composite resin samples with 1%, 2%, and 5% concentrations of NAg were prepared. The antimicrobial effectiveness of NAg was assessed against Streptococcus mutans, Streptococcus sanguis, and Lactobacillus acidophilus by the biofilm inhibition test (three-day-old biofilms), eluted components test (on days 3, 15, and 30), and disk-diffusion agar test after 48 hours. Measures of central tendency and index of dispersion were used to determine colony-forming units. Kruskal-Wallis test and Mann-Whitney U test were also used. Results. The biofilm inhibition test showed a significant decrease in the colonies of S. mutans (87.64%, 96.47%, and 99.76% decrease), S. sanguis (98.13%, 99.47%, and 99.93% decrease), and L. acidophilus (81.59%, 90.90%, and 99.61% decrease) at 1%, 2%, and 5% concentrations of Nag, respectively, compared to the control groups. The colony-forming unit (CFU)/mL of tested microorganisms continuously decreased with increased NAg concentration. In the eluted component test, no significant differences were noted in the 3rd, 15th, and 30th days between the different concentrations of Nag-containing composite resin disks and control samples. According to the disk-diffusion agar test, there was no growth inhibition zone for the composite resin disks containing 1% and 2% concentrations of Nag. However, the growth inhibition zone was seen with a 5% concentration, with a diameter of 9.5±0.71 mm for S. mutans, 8.5±0.71 mm for S. sanguis, and 8±1.41 for L. acidophilus. Conclusion. The incorporation of NAg into composite resins has antibacterial effects, possibly preventing dental caries around fixed orthodontic retainers.

Fixed orthodontic retainers and periodontal health

Data sources The following electronic databases were searched from 1946 to 31 August 2019: Medline, Embase, the Cochrane Oral Health Group's Trials Register, CENTRAL, ClinicalTrials.gov, the National Research Register and Pro-Quest Dissertation Abstracts and Thesis database.Study selection The following study designs were eligible: randomised controlled trials (RCTs), controlled clinical trials, cohort studies of prospective and retrospective design, and cross-sectional studies that reported periodontal measurements on patients who received fixed retention after orthodontic therapy. Studies irrespective of their language were selected by two reviewers independently.Data extraction and synthesis Data extraction from the selected studies and risk of bias assessments were performed by two reviewers independently. Specific risk of bias tools were used according to the pertinent research designs of the included studies. Criteria for conducting a meta-analysis were not met and a qualitative synthesis was conducted.Results Twenty-nine studies fulfilled the eligibility criteria; that is, 11 RCTs, four prospective cohort studies, one retrospective cohort study and 13 cross-sectional studies. The quality of the evidence was low for most of the studies included in this review. Contrary to the general consensus, two RCTs, one prospective cohort study and two cross-sectional studies identified poorer periodontal health in patients with fixed orthodontic retainers.Conclusions The authors of this systematic review concluded that fixed orthodontic retainers in the majority of the 29 included studies seemed to be a method of retention that is rather compatible with periodontal health, or at least not related to severe detrimental consequences for the periodontium. No recommendations on the best type of fixed retainer to use could be given. High-quality evidence from long-term studies is necessary to provide definitive conclusions on the relationship between fixed retainers and periodontal health.

Clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients: a retrospective study

PURPOSE

The aim of this study was to evaluate clinical factors affecting the longevity of fixed retainers and the influence of fixed retainers on periodontal health in periodontitis patients.

METHODS

In total, 52 patients with at least 2 years of follow-up after periodontal and orthodontic treatment were included in this study. After scaling and root planing, orthodontic treatment with fixed appliances or clear aligners was performed. Fixed retainers with twist-flex stainless steel wires were bonded to the palatal or lingual sides of anterior teeth. Changes in clinical parameters, including the plaque index, gingival index, calculus index (CI), probing pocket depth, and radiographic bone levels, were evaluated before bonding of fixed retainers and at a 12-month follow-up. Cumulative survival rates (CSRs) for retainer failure were evaluated according to sex, site, CI, stage of periodontitis, and the severity of the irregularity with the log-rank test and hazard ratios (HRs).

RESULTS

Twelve months after bonding of fixed retainers, improvements were observed in all clinical parameters except CI and radiographic bone gain. The overall CSR of the retainers with a CI <1 at the 12-month follow-up after bonding of fixed retainers was significantly higher than that of the retainers with a CI ≥1 at the 12-month follow-up (log-rank test; P<0.001). Patients with stage III (grade B or C) periodontitis had a higher multivariate HR for retainer failure (5.4; 95% confidence interval, 1.22-23.91; P=0.026) than patients with stage I (grade A or B) periodontitis.

CONCLUSIONS

Although fixed retainers were bonded in periodontitis patients, periodontal health was well maintained if supportive periodontal treatment with repeated oral hygiene education was provided. Nonetheless, fixed retainer failure occurred more frequently in patients who had stage III (grade B or C) periodontitis or a CI ≥1 at 12-month follow-up after bonding of fixed retainers.

Fixed Orthodontic Retainers Do Not Seem to Adversely Affect Periodontal Health

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

The effects of fixed orthodontic retainers on periodontal health: A systematic review. Arn M, Dristas K, Pandis N, Kloukos D. Am J Orthod Dentofacial Orthop 2020;157:156-64.

SOURCE OF FUNDING

Information is not available and the authors did state any specific funding for this study and report no potential conflicts of interest.

TYPE OF STUDY/DESIGN

Systematic review.

Innovative customized CAD/CAM nickel-titanium lingual retainer versus standard stainless-steel lingual retainer: A randomized controlled trial

Objective

To compare computer-aided design and computer-aided manufacturing (CAD/CAM) customized nitinol retainers with standard stainlesssteel fixed retainers over a 12-month study period.

Methods

This randomized controlled trial (RCT) was conducted on 62 patients randomly allocated to a control group that received stainless-steel retainers or a test group that received customized CAD/CAM nickel-titanium retainers. Four time points were defined: retainer placement (T0) and 1-month (T1), 6-month (T2), and 12-month (T3) follow-up appointments. At each time point, Little's irregularity index (LII) (primary endpoint) and dental stability measurements such as intercanine width were recorded in addition to assessment of periodontal parameters. Radiological measurements such as the incisor mandibular plane angle (IMPA) were recorded at T0 and T3. Failure events (wire integrity or debonding) were assessed at each time point.

Results

From T0 to T3, LII and other dental measurements showed no significant differences between the two groups. The data for periodontal parameters remained stable over the study period, except for the gingival index, which was slightly, but significantly, higher in the test group at T3 (p = 0.039). The IMPA angle showed no intergroup difference. The two groups showed no significant difference in debonding events.

Conclusions

This RCT conducted over a 12-month period demonstrated no significant difference between customized CAD/CAM nickel-titanium lingual retainers and standard stainlesssteel lingual retainers in terms of dental anterior stability and retainer survival. Both retainers eventually appeared to be equally effective in maintaining periodontal health.

Retention Protocols and Factors Affecting Retainer Choice among Iraqi Orthodontists

Background

To identify the most common retention protocols practiced by Iraqi orthodontists using a specially designed e-survey. Furthermore, this study aimed to assess the effect of sociodemographic factors on the participant's choice.

Methods

Two hundred and twenty-five questionnaires with 23 multiple choice questions were sent to members of the Iraqi Orthodontic Society. The questionnaire was organized into four sections representing information about sociodemographic status of the orthodontists, factors affecting the selection of the retention system, commonly used retainers in the upper arch and lower arch, and duration of the retention system. The chi-square test was used to test the significant association between different variable and sociodemographic factors.

Results

The response rate was 87.5%. The majority of the respondents considered the original malocclusion (80.2%) and clinical experience (49.7%) as the main factors for choosing the retention protocol. In the maxillary arch, a combination of vacuum-formed retainer and fixed retainer (35%) was mostly applied; in the mandibular arch, a fixed retainer was mainly used (46.7%). Most of the respondents recommended initial full-time wearing of a removable appliance (78.2%), especially in the first 3-6 months (47.2%). According to the respondents, bonding a fixed retainer to all anterior teeth was most common (79.7%), fabricated, and adapted directly inside the patient's mouth (75.1%). More than half used flowable composite (54.8%) and recommend leaving the retainer forever (53.8%). Most of the variables showed a statistically significant association between the sociodemographic factors and type, duration, and fabrication of the retainer used.

Conclusions

A combination of removable and fixed retainers was commonly used in orthodontics retention, and sociodemographic factors significantly affected retainer choice.