Orthodontic bonded retainers

Retention is usually necessary following orthodontic treatment to overcome the elastic recoil of the periodontal supporting fibres and to allow remodelling of the alveolar bone. The degree of change is variable and largely unpredictable. Bonded lingual retainers have been shown to be an effective means of retaining aligned anterior teeth in the post-treatment position in the long term. Two basic designs of lingual bonded retainers are currently in use. Rigid mandibular canine-to-canine retainers are attached to the canines only. They are effective in maintaining intercanine width but less so in preventing individual tooth rotations. Flexible spiral wire retainers are bonded to each tooth in the segment, their flexibility allowing for physiological movement of the teeth. This design is more effective at preventing rotation of the bonded teeth. Failure of bonded retainers may occur at the wire-composite interface, at the adhesive-enamel interface or as a stress fracture of the wire. Failure of a retainer may lead to unwanted tooth movement. In many cases it will be possible to repair the appliance in the mouth. However, in some instances it will be necessary to replace the retainer. A disadvantage of fixed retainers is that they complicate oral hygiene procedures, and favour the accumulation of plaque and calculus. Despite this, the presence of a bonded retainer appears to cause no increase in incidence of caries or periodontal disease. Use of interdental cleaning aids is required to ensure adequate oral hygiene.     

A Prospective Randomized Study of Different Retainer Types

BACKGROUND AND AIM: In recent years, fixed lingual retainers have been gaining importance in relapse prevention. The aim of this prospective, randomized study was to compare different types of fixed retainers used for stabilization of the lower anterior segment with respect to detachment rate, relapse, periodontal and oral hygiene problems, as well as subjective patient discomfort. PATIENTS AND METHOD: Two types of fixed, customized canine-to-canine retainers (attached to six teeth) with wire diameters of 0.0215" and 0.0195" as well as one type of prefabricated canine-and-canine retainer (bonded to two teeth) were investigated in a total of 103 patients. Some retainers were inserted under dry field conditions using a rubber dam, and the others under relatively dry conditions using cotton rolls. In addition, two types of composite, Heliosit and Concise, were compared. RESULTS: The canine-and-canine retainer displayed an 18% detachment rate, a value significantly lower than the 29% determined for the 0.0195" canine-to-canine retainers. The 0.0215" canine-to-canine retainer had the highest detachment rate (53%). The 37% detachment rate with dry field bonding was slightly higher than the 32% with relatively dry field bonding. Comparison of the composites showed a significantly higher detachment rate for Heliosit (73%) than for Concise (27%). Plaque accumulation increased with all retainer types in the course of the study, but with no significant inter-group differences. Tooth position with canine-to-canine retainers showed a good degree of stability. The canine-and-canine retainer induced frequent relapse of incisors not bonded to the retainer. In view of their higher rate of subjective discomfort, canine-and-canine retainers were given a significantly poorer rating than their canine-to-canine counterparts.     

Hygiene status associated with different types of bonded, orthodontic canine-to-canine retainers

The present study was performed to test whether bonded, orthodontic canine-to-canine retainers made of spiral wire tended to accumulate more plaque than retainers made of plain wire, and whether the presence of such retainers caused any damage to the teeth involved. 44 patients were classified in eight strata according to age, gender and gingival status. From each stratum, the patients were randomly divided into 4 groups, each of which received either retainers made of thick plain wire bonded only to the canines, thick twisted wired bonded only to the canines, thin twisted wire bonded to each tooth or removable retainers. Accumulation of plaque and calculus along the gingival margin and gingival inflammation were scored in lingual areas from canine to canine at time of fixed appliance removal and again 4 months after retainer insertion. In addition, accumulation of plaque and calculus and development of caries along the retainer wires were scored after 4 months. The results revealed no differences between the groups for any of the variables. No differences in accumulation of plaque was found between baseline and follow-up examinations. Gingival bleeding was scored less frequently after 4 months in retention than at time of debonding.     

Long-term influence of fixed lingual retainers on the development of gingival recession: A retrospective,longitudinal cohort study

Objective:To investigate the long-term influence of fixed lingual retainers on the development of mandibular gingival recession and to compare the prevalence with untreated individuals.Materials and Methods:The material consisted of 144 subjects: 96 orthodontically treated patients followed for 5 years after therapy and 48 untreated age-matched subjects. The treated patients were divided in two groups: one receiving a fixed mandibular retainer (n = 48) and one receiving no form of retention in the mandible (n = 48). The presence or absence of gingival recession and calculus accumulation were scored before treatment (T0), after debonding (T1), and 5 years after debonding (T5) for each tooth in the mandibular intercanine region using plaster models and intraoral photographs. The chi-square test, one-way ANOVA, and Cochran''s Q test were used to evaluate inter- and intragroup differences.Results:The prevalence of patients with recession increased gradually and significantly throughout the observation periods in all groups, but the intergroup differences at T5 were not significant. Significantly more calculus accumulation was observed at T5 in the retainer group compared with the group without retainers.Conclusions:Long-term presence of fixed lingual retainers does not seem to increase the development of mandibular gingival recession, but does increase calculus accumulation.     

Clinical comparison of a multistranded wire and a direct-bonded polyethylene ribbon-reinforced resin composite used for lingual retention.

OBJECTIVE: The reliability of posttreatment canine-to-canine retention with resin composite retainers reinforced with plasma-treated woven polyethylene ribbons was compared to the reliability of directly bonded, multistranded wire retainers. METHOD AND MATERIALS: This prospective study was based on an assessment of 20 consecutive patients (eight women and 12 men with a mean age of 22.4 years) who required a fixed canine-to-canine retainer after undergoing orthodontic treatment. The type of retainer used was randomized for each patient. A follow-up examination was carried out once every 3 months. The length of time the retainers stayed in place without resin fracture or loosening from the teeth at one or more points was evaluated. The study's endpoint was 24 months after the retainer had been bonded. RESULTS: The ribbon-reinforced retainer remained in place for an average of 11.5 months, and the multistranded wire for a mean of 23.6 months. The difference was statistically significant. CONCLUSION: In terms of reliability for permanently fixed orthodontic retention from canine to canine, the direct-bonded multistranded wire is superior to the plasma-treated polyethylene woven ribbon and resin retainer.     

Clinical experience with direct-bonded orthodontic retainers.

The experience obtained in clinical evaluation of forty-three direct-bonded mandibular canine-to-canine retainers after a minimum observation period of 1 year (range, 1 to 2.5 years) is summarized. Results indicate that the bonded retainer has all the advantages of a fixed soldered retainer, in addition to being invisible. Patient acceptance was excellent, and the failure rate in terms of loose retainers was low. Also, for a number of other retention problems, direct bonding with different types of lingual wire seems to open up a range of promising new possibilities.     

Long-term follow-up of maxillary incisors with severe apical root resorption

The purpose of the study was to analyse the mobility of teeth with severe orthodontically induced root resorption, at follow-up several years after active treatment, and to evaluate mobility in relation to root length and alveolar bone support. Seventy-three maxillary incisors were examined in 20 patients, 10-15 years after active treatment in 13 patients (age 24-32 years) and 5-10 years after active treatment in seven patients (age 20-25 years). All had worn fixed or removable retainers; seven still had bonded twistflex retainers. Total root length and intra-alveolar root length were measured on intra-oral radiographs. Tooth mobility was assessed clinically according to Miller's Index (0-4) and the Periotest method. Crestal alveolar bone level, periodontal pocket depth, gingival, and plaque indices, occlusal contacts during occlusion and function, and dental wear were recorded. There was a significant correlation (P < 0.05) between tooth mobility, and total root length and intra-alveolar root length. No correlation was found between tooth mobility and retention with twistflex retainers. None of the variables for assessment of periodontal status, occlusion and function were related to total root length or tooth mobility. It is concluded that there is a risk of tooth mobility in a maxillary incisor that undergoes severe root resorption during orthodontic treatment, if the remaining total root length is < or = 9 mm. The risk is less if the remaining root length is > 9 mm. Follow-up of teeth with severe orthodontically induced root resorption is indicated.     

Upper bonded retainers: Survival and failure rates

Objective:To assess the frequency and type of upper bonded retainer failure and to identify possible predisposing factors.Materials and Methods:The records of 466 consecutive patients with upper bonded retainers were analyzed retrospectively with respect to retainer failures and failure type as well as timing of failure, differences among operators, and the number of defects of the multibracket appliances (MB) prior to the retention period.Results:A total of 58.2% of all patients experienced retainer failures. The average failure odds were 1.26 failures per retainer. The odds were highest for 3-3 retainers (1.37) and lowest for the 1-1 retainer (0.54). The detachment and total loss rates were significantly influenced by operator experience—both rates were lower for experienced practitioners. Total retainer losses occurred more frequently in case of previous MB defects, while retainer fractures were seen more frequently when the retainer included the canines.Conclusions:Upper bonded retainer failures are a frequent problem during the retention period (58.2% of patients). Less operator experience correlated with higher failure rates. An increased number of total retainer losses must also be expected with a decreasing number of bonding sites and in cases involving previous MB defects.     

A Prospective Randomized Study of Different Retainer Types

Background and Aim: In recent years, fixed lingual retainers have been gaining importance in relapse prevention. The aim of this prospective, randomized study was to compare different types of fixed retainers used for stabilization of the lower anterior segment with respect to detachment rate, relapse, periodontal and oral hygiene problems, as well as subjective patient discomfort. Patients and Method: Two types of fixed, customized canine-to-canine retainers (attached to six teeth) with wire diameters of 0.0215" and 0.0195" as well as one type of prefabricated canine-and-canine retainer (bonded to two teeth) were investigated in a total of 103 patients. Some retainers wer inserted under dry field conditions using a rubber dam, and the others under relatively dry conditions using cotton rolls. In addition, two types of composite, Heliosit^® and Concise™, were compared. Results: The canine-and-canine retainer displayed an 18% detachment rate, a value significantly lower than the 29% determined for the 0.0195" canine-to-canine retainers. The 0.0215" canine-to-canine retainer had the highest detachment rate (53%). The 37% detachment rate with dry field bonding was slightly higher than the 32% with relatively dry field bonding. Comparison of the composites showed a significantly higher detachment rate for Heliosit^® (73%) than for Concise™ (27%). Plaque accumulation increased with all retainer types in the course of the study, but with no significant inter-group differences. Tooth position with canine-to-canine retainers showed a good degree of stability. The canine-and-canine retainer induced frequent relapse of incisors not bonded to the retainer. In view of their higher rate of subjective discomfort, canine-and-canine retainers were given a significantly poorer rating than their canine-to-canine counterparts. Zusammenfassung Hintergrund und Ziel: In den letzten Jahren gewinnen die Lingualretainer zur Rezidivprophylaxe an Bedeutung. Ziel der Studie war es, prospektiv und randomisiert verschiedene permanente Retainersysteme zur Stabilisierung der Unterkieferfront in Bezug auf Ablöseraten, Rezidive, parodontale und mundhygienische Probleme sowie subjektive Belastungen zu vergleichen. Patienten und Methode: Es wurden zwei an sechs Zähnen adhäsiv befestigte (Sechspunktretainer) der Drahtstärken 0,0215" und 0,0195" und ein konfektionierter, an zwei Zähnen befestigter Retainer (Zweipunktretainer) verwendet. Ein Teil der Retainer wurde unter Kofferdam eingesetzt, ein anderer unter relativer Trockenlegung mit Watterollen. Des Weiteren wurden die Komposite Heliosit^® Orthodontic und Concise™ Orthodontic verglichen. Ergebnisse: Der Zweipunktretainer wies mit 18% eine signifikant geringere Ablöserate auf als der Sechspunktretainer der Drahtstärke 0,0195" mit 29%. Der Sechspunktretainer der Stärke 0,0215" hat mit 53% die höchste Ablöserate. Die Ablösungsrate lag bei absoluter Trockenlegung mit 37% geringfügig höher als bei relativer Trockenlegung mit 32%. Der Vergleich der beiden Komposite ergab eine signifikant größere Ablösungsrate für Heliosit^® (73%) gegenüber Concise™ (27%). Die Plaqueakkumulation nahm bei allen drei Retainertypen im Verlauf der Studie zu ohne signifikante Unterschiede zwischen den einzelnen Retainertypen. Die Zahnstellung blieb bei den beiden Sechspunktretainern weitgehend stabil. Bei dem Zweipunktretainer kam es gehäuft zu Rezidiven der nicht gefassten Schneidezähne. Zweipunktretainer schnitten durch die höhere Angabe subjektiver Beschwerden bei der Fragebogenauswertung zur Patientenbelastung signifikant schlechter ab als Sechspunktretainer.     

Comparison of Incisor Mobility after Insertion of Canine-to-Canine Lingual Retainers Bonded to Two or to Six Teeth A Clinical Study

BACKGROUND: Fixed appliance therapy often extends over several years. Debonding is warmly welcomed and is often seen by the patient as the end of treatment. Yet both patients and parents often underestimate the importance of the subsequent retention period and the speed at which negligence in this treatment phase results in relapse. Bonded retainers guarantee excellent long-term stability at least while they are in situ. The reliable attachment of lingual retainers with modern bonding techniques has led to widespread application of this retention method. The present study investigated its influence on tooth mobility and on the damping properties of the periodontal tissue, by means of a dynamic measuring method (Periotest). PATIENTS AND METHOD: For this purpose two groups with mandibular bonded retainers and one control group were formed. The control group wore removable retention appliances. In all groups, active treatment with fixed appliances had been completed at least half a year before baseline. RESULTS: The results showed that bonded retainers had a negative impact on the damping properties of the periodontal tissue and thus in the broader sense on tooth mobility. Tooth mobility decreased with the number of teeth to which the retainer was bonded but remained, as in the control group, within the physiologic range.     

Lower Fixed Retainers: Bonded On All Teeth Or Only On Canines? A Systematic review

ObjectiveTo evaluate the stability after orthodontic treatment between two types of lower fixed retainers: those bonded onto all anterior teeth or those bonded only onto the canines.Materials and MethodsThe following electronic databases were consulted: PubMed, Scopus, Web of Science, Cochrane Library, Lilacs, OpenGrey, ClinicalTrials, and Google Scholar. No restriction of language or year were applied. After selection of studies, risk-of-bias evaluation and qualitative synthesis of the included studies were performed using The Cochrane Collaboration''s tool for randomized studies and the “Risk of Bias in Non-randomized Studies of Interventions” (ROBINS-I) tool for nonrandomized studies, and a summary of the overall strength of evidence was presented using the “Grading of recommendations, assessment, development and evaluation” tool.ResultsAmong the 180 studies retrieved from the searches, five were included in this review. Three of them showed a low risk of bias, while two presented a high risk of bias. With regard to stability, two studies reported better stability for retainers bonded to all six teeth, while the other three showed no difference. The retainer bonded to all teeth presented a higher breakage rate in one study.ConclusionsStability seems better with lower fixed retainers bonded on all anterior teeth. The breakage rate may not change according to the bonding. However, studies with greater methodological soundness are necessary to reach a more reliable conclusion.     

Caries and periodontal reactions associated with long-term use of different types of bonded lingual retainers

An investigation was carried out (1) to test the tendency of different types of bonded retainers to accumulate plaque and calculus and (2) to find out whether long-term use of bonded retainers caused any damage to the teeth involved. Two test groups of patients--one with 3-3 retainers made of 0.032-inch spiral wire, and the other with 3-3 retainers made of 0.032-inch plain wire--and a reference group of persons without 3-3 retainers were compared. Also, a test group of patients with retainers made of flexible spiral wire (0.0195 inch) bonded lingually to each anterior tooth in the maxilla was compared to a reference group of patients with retention plates in the maxilla. All the persons selected had received routine orthodontic treatment with a multibonded edgewise light wire technique and had been out of active treatment for 1 to 8 years. Different indices were used to score accumulation of plaque and calculus, prevalence of caries, and periodontal reactions. The findings indicated that there was no basis on which to claim that retainers made of spiral wire accumulated more plaque and calculus than retainers made of plain wire. The presence of a bonded lingual retainer and the occasional accumulation of plaque and calculus gingival to the retainer wire after long-term use caused no apparent damage to the hard and soft tissues adjacent to the wire.     

Bonded Retainers - Clinical Reliability

Bonded retainers have become a very important retention appliance in orthodontic treatment. They are popular because they are considered reliable, independent of patient cooperation, highly efficient, easy to fabricate, and almost invisible. Of these traits, reliability is the subject of this clinical study. A total of 549 patients with retainers were analyzed with regard to wearing time, extension of the retainer, mean time between failures, operator, and age of patient. The average frequency of breakage or loss was 0.55 per retainer per year. This frequency was dependent primarily on the operator who bonded the retainer and on the extent of the retainer. If the upper canines were involved, reliability was lower. The majority of failures occurred during the first 3 to 6 months. The study showed that bonded retainers represent a highly efficient and reliable retention appliance suited to long-term use.     

Incidence of white spot formation after bonding and banding

White spot or areas of decalcification are carious lesions of varying extent. The incidence and severity of white spots after a full term of orthodontic treatment were studied among patients in the separate private practices of two of the authors. To establish a base line of comparison, the presence of white spots in a random sample of untreated persons was observed. The incidence of white spots among patients treated by a multibonded technique was recorded at the time of debonding. In addition, white spots were sought in the before- and after-treatment Kodachrome slides of persons whose maxillary incisors had been handed. It was found that individual teeth, banded or bonded, exhibited significantly more white spot formation than was found in the control group. For the teeth studied, there was no difference in white spot formation in those that were banded or bonded. The labiogingival area of the maxillary lateral incisors had the highest incidence of white spots. When studied by segments, the highest incidence occurred among the maxillary incisors; the lowest was in the maxillary posterior segment. No white spots were found on the lingual surfaces of mandibular canines and incisors after prolonged use of a canine-to-canine bonded retainer. These findings suggest a relationship between resistance to white spot formation and the rate of salivary flow. Despite the lack of any preventive fluoride program among the study groups, 50% of the patients demonstrated resistance to white spot formation. The obvious degree of latrogenic damage during orthodontic treatment suggests the need for preventive programs using fluoride. Further clinical research is needed.     

A bonding technique for fixed maxillary retainers

Abstract

Maintaining incisor alignment is an important goal of orthodontic retention and can only be guaranteed by placement of an intact, passive and permanent fixed retainer. Here we describe a reliable technique for bonding maxillary retainers and demonstrate all the steps necessary for both technician and clinician. The importance of increasing the surface roughness of the wire and teeth to be bonded, maintaining passivity of the retainer, especially during bonding, the use of a stiff wire and correct placement of the retainer are all discussed. Examples of adverse tooth movement from retainers with twisted and multistrand wires are shown.     

Torque resistance of different stainless steel wires commonly used for fixed retainers in orthodontics

Objective: Movements of teeth splinted by fixed retention wires after orthodontic treatment have been observed. The aetiological factors for these movements are unknown. The aim of this in vitro study was to compare the resistance to torque of different stainless steel wires commonly used for fixed retainers in orthodontics. Materials and Methods: Torquing moments acting on a retainer wire were measured in a mechanical force testing system by applying buccal crown torque to an upper lateral incisor in both a 3-teeth and in a 2-teeth setup. Seven stainless steel wires with different shape, type (plain, braided, coaxial, or chain) and dimensions were selected for this study. Results: For a torquing angle of 16.2° in the 3-teeth setup torsion moments can vary between 390?cNmm and 3299?cNmm depending on the retainer wire. For the 2-teeth setup the torsion moments are much smaller. Exposure to the flame of a butane-gas torch for 10 seconds to anneal the wire reduces the stiffness of the retainer wire. Conclusions: Clinicians must select wires for fixed retainers very carefully since the difference in resistance to torque is large. A high level of torque control can be achieved with a plain 0.016?×?0.016-inch or a braided 0.016?×?0.022-inch stainless steel wire. A tooth attached by a retainer wire to only one neighbouring tooth is less resistant to torque than a tooth connected to two neighbouring teeth. Annealing a retainer wire with a flame reduces the stiffness of the wire markedly and can lead to a non-uniform and non-reproducible effect.     

Level of Satisfaction in the Use of the Wraparound Hawley and Thermoplastic Maxillary Retainers

ObjectiveTo compare the level of satisfaction in the use of wraparound Hawley and thermoplastic maxillary retainers.Materials and MethodsThe study sample included 70 orthodontic patients (24 males and 46 females), who were in the retention stage (mean age = 20.80 years). All patients wore the two types of maxillary retainer for 1 month each, along with a 3×3 fixed mandibular retainer. After the use of each retainer, the patients responded to a questionnaire evaluating the level of satisfaction with their use of the maxillary retainer. Intergroup comparison was performed by independent t tests. Chi-square test was used to evaluate preference for the type of retainer by gender.ResultsThe thermoplastic retainer was better for swallowing and the wraparound Hawley appliance was better for hygiene and durability. The other factors evaluated (adaptation, speech, comfort, esthetics, satisfaction, and fitting) did not show significant differences between the retainers. There was also no significant difference in preference for the appliances.ConclusionsRegarding the overall satisfaction and the preference, there was no difference between the wraparound Hawley and thermoplastic retainers. The wraparound Hawley appliance was better in hygiene and resistance than the thermoplastic retainer; and the thermoplastic appliance was better than the wraparound Hawley for swallowing fluids and saliva.     

An approach to maintain orthodontic alignment of lower incisors without the use of retainers

The purpose of this investigation was to examine the long-term stability of orthodontic alignment of lower incisors without the use of retainers. The study sample comprised 56 patients treated according to a protocol that included over-correction of rotated teeth at an early stage of treatment and systematic enamel reduction (stripping) of the approximal surfaces in the mandibular anterior region, both during treatment and follow-up. Care was also taken to maintain dental arch form and to avoid lateral expansion of the lower dental arch and proclination of the incisors. Dental study casts were obtained pre-treatment, at the end of treatment, and 3 years post-treatment. Alignment of the mandibular incisors was recorded using Little's irregularity index. The inter-canine distance and the sum of the mesio-distal widths of the mandibular incisors and canines were also measured.The total amount of enamel removed from the approximal surfaces of the lower anterior teeth ranged from 0.3 to 5.0 mm (mean 1.9 mm). The mean increase in irregularity index score of 0.6 from post-treatment to 3 years follow-up indicated good stability. In 45 per cent of the patients the change in score during this period was less than 0.5, indicating that the treatment approach presented may be considered an alternative strategy to placement of lower retainers to safeguard the stability of alignment of mandibular incisors.     

Change in dentition over 20 years from third decade of life

PurposePrevious studies have documented long-term, age-related change in the teeth, dental arches and occlusion. However, very few studies have investigated longitudinal age-related change in the dentition using 3-dimensional (3-D) measurement. The purpose of this study was to clarify age-related change in the dentition using a laser scanner.Materials and methodsWe used dental casts obtained from the same subjects in their twenties and forties. Subjects were selected based on near-normal occlusion. We investigated age-related variation in the dentition using 3-D measurement.ResultsAge-related change in the dentition was characterized by a decrease in maxillary and mandibular width, an increase in maxillary length, and a decrease in mandibular length. Measurement of angulation revealed that the maxillary canines and molars were mesially inclined. We observed labial inclination of the maxillary incisors, and lingual inclination of the mandibular incisors, as well as the maxillary and mandibular canines and molars. Overjet, overbite, and the irregularity index all showed an increase, while occlusal vertical dimension showed a decrease. Multiple regression analysis indicated that lingual inclination of the lower central incisors was related to an increase in the irregularity index, and that lingual inclination of the upper canines and decrease in occlusal vertical dimension of the anterior teeth were related to increased overbite.ConclusionThe present findings showed that age-related changes in angulation and inclination of each tooth should be taken into account when providing occlusal rehabilitation or post-orthodontic retention.     

Commentaries on scientific paper published in this edition

Abstract

Accurate easy placement bonded retainers have long been a desired aspect of contemporary orthodontic treatment. This article offers the reader a simple and precise method of placing a fixed bonded retainer. This technique also has the advantage of providing a retainer that can be used as both the positioner and the dual removable retainer.