Clinical comparisons of different fixed orthodontic retainers

ABSTRACT Objective: The aim of this prospective clinical study was to compare the clinical outcomes of three different fixed lingual retainers, in terms of effects on periodontal health and success rate. Methods: Forty five patients aged 13 to 25 years were randomly assigned into three groups, using bonded upper and lower lingual retainers. The study groups were as follows: Group 1- Bond-A-Braid®, Group 2- everStick® ORTHO, Group 3- Super-Splint. The follow-up appointments were performed two weeks (Baseline=T0), one month (T1), three months (T2), and six months (T3) after the application of retainers. Plaque Index (PI), Gingival Index (GI), Probing Depth (PD), Bleeding in Probing (BOP) and Retainer Failure were assessed at each appointment. Results: The everStick Ortho group showed significantly lower PI values on the upper-lower lingual side after three (p=0.008) and six (p=0.001) months. The everStick Ortho group had significantly lower upper lingual (GI) levels after six months, and lower lingual side levels after one month. The Super-Splint group showed significantly lower PD values on the upper lingual side after six months. The everStick Ortho group presented significantly lower BOP levels after six months on the upper lingual side. No significant differences between the groups (p>0.05) in terms of retainer failure were found. Conclusions: The everStick Ortho group presented better results in terms of periodontal health. The failure rates of the retainers were similar.

RESUMO Objetivo: O objetivo do presente estudo clínico prospectivo foi comparar a taxa de sucesso de três tipos de contenção lingual fixa e seus efeitos clínicos sobre a saúde periodontal. Métodos: Quarenta e cinco pacientes, com idades entre 13 e 25 anos, usando contenções fixas coladas nas arcadas superior e inferior foram agrupados, aleatoriamente, nos três seguintes grupos: Grupo 1 - Bond-A-Braid®; Grupo 2 - everStick® ORTHO; e Grupo 3 - Super-Splint. As consultas de acompanhamento foram feitas após duas semanas (inicial = T0), um mês (T1), três meses (T2) e seis meses (T3) da instalação das contenções. Em todas as consultas, foram avaliados o Índice de Placa (IP), Índice Gengival (IG), Profundidade de Sondagem (PS), Sangramento à sondagem (SAS) e Falha da Contenção. Resultados: O grupo everStick Ortho mostrou valores de IP significativamente menores nas faces linguais dos dentes superiores e inferiores após três (p=0,008) e seis (p=0,001) meses. O grupo everStick Ortho também apresentou níveis significativamente menores de IG na face lingual dos dentes superiores após seis meses, e face lingual dos dentes inferiores após um mês. O grupo Super-Splint mostrou valores significativamente menores de PS na face lingual dos dentes superiores após seis meses. O grupo everStick Ortho apresentou níveis significativamente menores de SAS na face lingual dos dentes superiores após seis meses. Quanto à falha na contenção, não houve diferença significativa (p>0,05) entre os grupos. Conclusões: O grupo everStick Ortho apresentou os melhores resultados em termos de saúde periodontal. As taxas de falha das contenções foram semelhantes.

The effect of bonded resin surface area on the detachment force of lingual bonded fixed retainers: An in vitro study / 대한치과교정학회지

OBJECTIVE: The aims of this study were to evaluate the relationship between the detachment force and bonding resin surface are and to determine the resin bonding surface area that would provide adequate bonding strength with minimum resin volume. METHODS: One hundred and sixty human premolars were randomly divided into 4 groups of 40 teeth each. The diameter of the resin surface area in each group was as follows: group 1, 1.5 mm; group 2, 2.5 mm; group 3, 3.5 mm; and group 4, 4.5 mm. Respond Dead Soft straight (length 0.0175 inch) was used to fabricate the retainers, and Transbond(TM) XT was used to fix the retainers to the tooth surfaces. A pair of teeth was embedded in acrylic blocks for each specimen. Thus, each group comprised 20 samples. Fixed retainers were bonded to the teeth, and vertical force was applied at the middle of wire. The force was measured using a universal testing machine. RESULTS: The mean value of detachment force was the highest for group 4 (102.38 +/- 2.92 N), followed by group 3 (63.54 +/- 2.21 N), group 2 (51.95 +/- 1.61 N), and group 1 (24.14 +/- 1.38 N). CONCLUSIONS: The detachment force of lingual fixed retainers was significantly affected as the area of the resin bonding surface increased. Considering the minimum bonding strength of brackets, a resin bonding surface area with a diameter of 3.5 mm would provide adequate bonding strength.

Non-surgical treatment and retention of open bite in adult patients with orthodontic mini-implants / 대한치과교정학회지

Successful treatment of the non-growing patient with an open bite of either dental skeletal pattern often presents a difficult challenge. The morphologic pattern in anterior open bite is characterized by longer vertical dimensions, an increase in development of the maxillary posterior dento-alveolar structure and a steep mandibular plane. In such cases, molar intrusion would be a good remedy for treatment. This article reports the successful treatment and retention of two anterior open-bite cases. We used orthodontic mini-implants for treatment and a circumferential retainer with posterior bite block or skeletal fixed retainer for retention. The diagnostic criteria and mechanics for appropriate treatment are discussed. Our results suggest that open bite can be reduced successfully with intrusion of molars using orthodontic mini-implants (OMI) without orthognathic surgery, and that circumferential retainer with posterior bite block and skeletal fixed retainer are effective for retention.

Periodontal tissue response following different types of fixed retainers in young adult dogs / 대한치과교정학회지

The purpose of this study was to evaluate the material for fixed type retainer, allowing physiologic tooth movement. and proper remodeling of periodontal tissue during retention period. The present study was performed to observe the histologic changes of periodontal tissue after application of different types of fixed type retainer after orthodontic tooth movement in young adult dogs. For this study, 4 young adult dogs were used as a experimental animal and experimental group was divided into three groups ; experimental group 1 contained right side maxillary third incisors and canines, experimental group 2 contained contralateral teeth of same animals, and control group contained mandibular premolars. And each dogs were applied the 4 different types of fixed type retainer to experimental group 1. The experimental teeth were ligated on the Sentalloy closed coil spring(R)(Tomy Co., Japan) from maxillary third incisors and canines and applied orthodontic force at initial 200gm-forced during 1 week. All the experimental animals were sacrificed on the 3rd week after the orthodontic teeth movement and then the specimens were taken, fixed in formalin, embeded in parafin, sectioned 6-8micrometer in thickness and stained with Hematoxylin-Eosin staining, and Masson's trichrome staining method. Examined under the light microscopy. The following results were observed. 1. There were observed that decreased infiltration of giant cells in pressure side and increased the new bone forming in tension side on the specimen of 6-stranded 0.0195' Respond(R)(G&H Co., U.S.A.) group. Periodontal ligament fibers were much compressed or elongated in 3-stranded 0.018', 0.020' Dentaflex(R)(Dentarum Co., Germany), and Superbond C&B(R)(Sun Medical Co., Japan) groups. 2. In experimental group 1, necrotic bone inside the alveolar bone of pressure side, forming of the sharpey's fiber in osteoid tissue, and remodeling of the periodontal ligament were observed in all animals. 3. In experimental group 2, it was observed that the amount of bone resorption was equal or decreased in pressure side, and increased new bone forming and significantly decreased infiltration of giant cell than the experimental group 1. By this results, it considered that 6-stranded Respond(R)(G&H Co., U.S.A.) wire was the most useful material allowing early periodontal tissue remodeling.