Shear Bond Strength and Adhesive Remnant of Three Protocols used for Bonding Orthodontic Brackets

Objective: To test the shear bond strength and the amount of adhesive remnant on the enamel after debonding of a conventional orthodontic composite system, a flowable composite resin, and a self-adhesive resin cement. Material and Methods: Thirty extracted bovine incisors were allocated in three groups, according to the type of adhesive: Group XT (Transbond XT), Group FL (Flow Z350), and Group RX (RelyX U100). All groups had etching with phosphoric acid. Groups XT and FL received primer before adhesive. Stainless steel metal brackets were bonded using the respective adhesive. Teeth were submitted to shear bond strength (SBS) test, followed by measurement of adhesive remnant. Intergroup comparison of SBS values were performed by one-way Anova and Tukey post-hoc test. Kruskal-Wallis test and the Mann-Whitney U-test were used to compare adhesive remnant. Results: Transbond XT presented higher bond strength than RelyX U100 and Flow Z350; all adhesives exhibited bond failure within the adhesive. All groups showed bond failure occurring within the adhesive. Transbond XT and RelyX U100 left significantly more adhesive remnant on the tooth surface than Flow Z350. Conclusion: All three adhesive systems had bond strength above the minimum for clinical routine use. As regards to bond strength, Transbond XT performed better than the resin cement and the flowable resin. Bond failure occurred within the adhesive in all groups.

Postretention stability after orthodontic closure of maxillary interincisor diastemas

Anterior spaces may interfere with smile attractiveness and compromise dentofacial harmony. They are among the most frequent reasons why patients seek orthodontic treatment. However, midline diastema is commonly cited as a malocclusion with high relapse incidence by orthodontists. Objectives: This study aimed to evaluate the stability of maxillary interincisor diastemas closure and the association of their relapse and interincisor width, overjet, overbite and root parallelism. Material and Methods: Sample comprised 30 patients with at least a pretreatment midline diastema of 0.5 mm or greater after eruption of the maxillary permanent canines. Dental casts and panoramic radiographs were taken at pretreatment, posttreatment and postretention. Results: Before treatment, midline diastema width was 1.52 mm (SD=0.88) and right and left lateral diastema widths were 0.55 mm (SD=0.56) and 0.57 mm (SD=0.53), respectively. According to repeated measures analysis of variance, only midline diastema demonstrated significant relapse. In the overall sample the average relapse of midline diastema was 0.49 mm (SD=0.66), whilst the unstable patients showed a mean space reopening of 0.78 mm (SD=0.66). Diastema closure in the area between central and lateral incisors showed great stability. Multivariate correlation tests showed that only initial diastema width (β=0.60) and relapse of overjet (β=0.39) presented association with relapse of midline diastema. Conclusions: Midline diastema relapse was statistically significant and occurred in 60% of the sample, while lateral diastemas closure remained stable after treatment. Only initial diastema width and overjet relapse showed association with relapse of midline diastema. There was no association between relapse of interincisor diastema and root parallelism. .

Postretention stability after orthodontic closure of maxillary interincisor diastemas.

UNLABELLED: Anterior spaces may interfere with smile attractiveness and compromise dentofacial harmony. They are among the most frequent reasons why patients seek orthodontic treatment. However, midline diastema is commonly cited as a malocclusion with high relapse incidence by orthodontists. OBJECTIVES: This study aimed to evaluate the stability of maxillary interincisor diastemas closure and the association of their relapse and interincisor width, overjet, overbite and root parallelism. MATERIAL AND METHODS: Sample comprised 30 patients with at least a pretreatment midline diastema of 0.5 mm or greater after eruption of the maxillary permanent canines. Dental casts and panoramic radiographs were taken at pretreatment, posttreatment and postretention. RESULTS: Before treatment, midline diastema width was 1.52 mm (SD=0.88) and right and left lateral diastema widths were 0.55 mm (SD=0.56) and 0.57 mm (SD=0.53), respectively. According to repeated measures analysis of variance, only midline diastema demonstrated significant relapse. In the overall sample the average relapse of midline diastema was 0.49 mm (SD=0.66), whilst the unstable patients showed a mean space reopening of 0.78 mm (SD=0.66). Diastema closure in the area between central and lateral incisors showed great stability. Multivariate correlation tests showed that only initial diastema width (ß=0.60) and relapse of overjet (ß=0.39) presented association with relapse of midline diastema. CONCLUSIONS: Midline diastema relapse was statistically significant and occurred in 60% of the sample, while lateral diastemas closure remained stable after treatment. Only initial diastema width and overjet relapse showed association with relapse of midline diastema. There was no association between relapse of interincisor diastema and root parallelism.

Maxillary incisors mesiodistal angulation changes in patients with orthodontically treated anterior superior diastemas / Alteração das angulações mesiodistais dos incisivos superiores em pacientes com diastemas anterossuperiores tratados ortodonticamente

OBJECTIVE: The aims of this study were to describe the patterns of maxillary incisor angulation in patients with upper interincisive diastemas, to evaluate angulation changes with treatment and posttreatment period, and to assess whether there are association between incisor angulation and interincisive diastema relapse. METHODS: The sample comprised 30 Class I or Class II patients with at least one pretreatment anterior diastema of 0.77 mm or greater after eruption of maxillary permanent canines. Data were obtained from panoramic radiographs at pretreatment, posttreatment and at least 2 years post-retention. RESULTS: Incisors presented a mesial tipping tendency after treatment, but only lateral incisors showed significant changes between pre and posttreatment stages. CONCLUSION: Regarding post-retention period, no changes were found. Finally, no relation was found between diastema relapse and maxillary incisor axial angulation.

OBJETIVO: esse trabalho teve por objetivo descrever o padrão de angulações mesiodistais dos incisivos superiores em pacientes com diastemas nessa área e observar as alterações dessas angulações durante e após o tratamento ortodôntico. Também objetivou analisar se existe associação entre as angulações mesiodistais desses dentes nos estágios inicial, final de tratamento e pós-contenção e a recidiva dos diastemas anterossuperiores. MÉTODOS: a amostra consistiu de 30 pacientes que foram avaliados antes do tratamento, logo após e passados 7 anos da remoção do aparelho ortodôntico. Os indivíduos apresentavam má oclusão de Classe I ou Classe II e, pelo menos, um diastema interincisivos com largura mínima de 0,77mm antes do tratamento. Além disso, os caninos superiores permanentes apresentavam a metade da coroa na cavidade bucal, no mínimo. RESULTADOS: as angulações dos incisivos apresentaram tendência à mesialização com o tratamento ortodôntico, sendo que houve diferença significativa apenas para as angulações dos incisivos laterais. No período pós-contenção, as angulações de todos os incisivos permaneceram estáveis. Não foi observada associação entre a recidiva dos diastemas e as angulações dos incisivos superiores. CONCLUSÃO: as angulações mesiodistais dos incisivos de pacientes com diastemas nessa área sofreram poucas modificações com o tratamento, havendo uma maior tendência de mesialização das coroas dos incisivos laterais. Os resultados obtidos com o tratamento permaneceram estáveis. Não houve associação entre a recidiva dos diastemas anterossuperiores e as posições mesiodistais dos dentes analisados.

Avaliação dos efeitos do Sistema Damon nas inclinações dentárias, dimensões dos arcos e suporte ósseo alveolar por meio da tomografia computadorizada de feixe cônico / Changes in arch dimensions, buccolingual inclinations and alveolar bony support during alignment using Damon MX: a CBCT study

Avaliação dos efeitos do Sistema Damon nas inclinações dentárias, dimensões dos arcos e suporte ósseo por meio da tomografia computadorizada de feixe cônico Este estudo objetivou analisar as alterações nas inclinações vestibulolinguais dos dentes, nas dimensões dos arcos e nas espessuras das tábuas ósseas vestibulares durante o alinhamento com Sistema Damon, como também identificar fatores pré-tratamento (espessura óssea inicial, larguras dos arcos, apinhamento) e alterações do tratamento (expansão dos arcos, vestibularização dos dentes) possivelmente associados. Vinte e dois adolescentes com dentadura permanente completa até primeiros molares, tratados sem extrações e apinhamento inicial mínimo de 4mm superior: -6,71mm (DP 2,99), inferior: -5,12mm (DP 2,03) foram escaneados por tomografia computadorizada de feixe cônico (TCFC) antes (T0) e após (T1) o alinhamento com o Sistema Damon. As dimensões dos arcos e as inclinações vestibulolinguais dos dentes foram avaliadas a partir das TCFC (T0 e T1) em modelos 3D e cortes multiplanares, enquanto o apinhamento foi mensurado nos modelos de estudo (T0). A spessura das tábuas ósseas vestibulares nos ¾ coronais e » apical da raiz dentária foram mensuradas por meio de imagens de tomográficas parassagitais (0,3mm de espessura) das duas fases T0 e T1, nas áreas de incisivos centrais superiores e de segundos pré-molares e primeiros molares superiores e inferiores. As variáveis foram submetidas ao teste de de Shapiro-Wilk para testar sua distribuição. As alterações de todas as variáveis de T0 para T1 foram comparadas por meio dos testes t pareado ou de Wilcoxon. A correlação entre as alterações das espessuras ósseas com os possíveis fatores associados foi verificada pelo coeficiente de correlação de Pearson ou teste de correlação de Spearman. O alinhamento com o Sistema Damon produziu expansões dos arcos associados à proclinação dos dentes e à redução na espessura óssea vestibular. As tábuas ósseas vestibulares tornaram-se...

This study aimed first to assess the changes in teeth buccolingual inclinations, arch dimensions, and buccal bony plate thicknesses occurred during the alignment phase using a self-ligating brackets system (Damon MX). Secondly, to identify pre-treatment (initial bone thickness, initial arch widths, initial crowding) or treatment parameters (amount of expansion, amount of buccal tipping) that could act as risk predictors for buccal bone reduction during orthodontic treatment. Twenty-two adolescents with complete permanent dentition until first molars, minimum initial crowding of 4mm - maxillary: -6.71 mm (SD 2.99), mandibular: - 5.12 mm (SD 2.03) - treated without extractions were scanned by cone beam computed tomography (CBCT) before (T0) and after (T1) alignment using Damon System. Arch dimensions and teeth buccolingual inclinations were evaluated by means of digital models and multiplanar reconstructed images both obtained from CBCT (T0 and T1), crowding was measured on study casts (T0). Alveolar buccal bone thickness overlying the ¾ coronal and the » apical of the root were measured in the areas of maxillary central incisors, as well as maxillary and mandibular premolars and first molars by means of cross-sectional images reconstructed with 0.3 mm thickness at T0 and T1, Distribution of the variables was verified by Shapiro-Wilks test. Changes in all variables from T0 to T1 were compared using paired t test or Wilcoxon test. The correlation between changes in bone thickness with its possible associated factors was assessed by Pearson correlation coefficient or Spearman correlation test. Alignment using Damon System produced substantial arch expansion associated with proclination of teeth and reduction in buccal bone thickness. The buccal bone plates overlying 25% of the mesiobuccal roots of the maxillary first molars became unmeasurable during the alignment phase. The reduction in the measurable buccal bone thickness, overlying...

Avaliação dos efeitos do Sistema Damon nas inclinações dentárias, dimensões dos arcos e suporte ósseo alveolar por meio da tomografia computadorizada de feixe cônico / Changes in arch dimensions, buccolingual inclinations and alveolar bony support during alignment using Damon MX: a CBCT study

Avaliação dos efeitos do Sistema Damon nas inclinações dentárias, dimensões dos arcos e suporte ósseo por meio da tomografia computadorizada de feixe cônico Este estudo objetivou analisar as alterações nas inclinações vestibulolinguais dos dentes, nas dimensões dos arcos e nas espessuras das tábuas ósseas vestibulares durante o alinhamento com Sistema Damon, como também identificar fatores pré-tratamento (espessura óssea inicial, larguras dos arcos, apinhamento) e alterações do tratamento (expansão dos arcos, vestibularização dos dentes) possivelmente associados. Vinte e dois adolescentes com dentadura permanente completa até primeiros molares, tratados sem extrações e apinhamento inicial mínimo de 4mm superior: -6,71mm (DP 2,99), inferior: -5,12mm (DP 2,03) foram escaneados por tomografia computadorizada de feixe cônico (TCFC) antes (T0) e após (T1) o alinhamento com o Sistema Damon. As dimensões dos arcos e as inclinações vestibulolinguais dos dentes foram avaliadas a partir das TCFC (T0 e T1) em modelos 3D e cortes multiplanares, enquanto o apinhamento foi mensurado nos modelos de estudo (T0). A spessura das tábuas ósseas vestibulares nos ¾ coronais e » apical da raiz dentária foram mensuradas por meio de imagens de tomográficas parassagitais (0,3mm de espessura) das duas fases T0 e T1, nas áreas de incisivos centrais superiores e de segundos pré-molares e primeiros molares superiores e inferiores. As variáveis foram submetidas ao teste de de Shapiro-Wilk para testar sua distribuição. As alterações de todas as variáveis de T0 para T1 foram comparadas por meio dos testes t pareado ou de Wilcoxon. A correlação entre as alterações das espessuras ósseas com os possíveis fatores associados foi verificada pelo coeficiente de correlação de Pearson ou teste de correlação de Spearman. O alinhamento com o Sistema Damon produziu expansões dos arcos associados à proclinação dos dentes e à redução na espessura óssea vestibular. As tábuas ósseas vestibulares tornaram-se...

This study aimed first to assess the changes in teeth buccolingual inclinations, arch dimensions, and buccal bony plate thicknesses occurred during the alignment phase using a self-ligating brackets system (Damon MX). Secondly, to identify pre-treatment (initial bone thickness, initial arch widths, initial crowding) or treatment parameters (amount of expansion, amount of buccal tipping) that could act as risk predictors for buccal bone reduction during orthodontic treatment. Twenty-two adolescents with complete permanent dentition until first molars, minimum initial crowding of 4mm - maxillary: -6.71 mm (SD 2.99), mandibular: - 5.12 mm (SD 2.03) - treated without extractions were scanned by cone beam computed tomography (CBCT) before (T0) and after (T1) alignment using Damon System. Arch dimensions and teeth buccolingual inclinations were evaluated by means of digital models and multiplanar reconstructed images both obtained from CBCT (T0 and T1), crowding was measured on study casts (T0). Alveolar buccal bone thickness overlying the ¾ coronal and the » apical of the root were measured in the areas of maxillary central incisors, as well as maxillary and mandibular premolars and first molars by means of cross-sectional images reconstructed with 0.3 mm thickness at T0 and T1, Distribution of the variables was verified by Shapiro-Wilks test. Changes in all variables from T0 to T1 were compared using paired t test or Wilcoxon test. The correlation between changes in bone thickness with its possible associated factors was assessed by Pearson correlation coefficient or Spearman correlation test. Alignment using Damon System produced substantial arch expansion associated with proclination of teeth and reduction in buccal bone thickness. The buccal bone plates overlying 25% of the mesiobuccal roots of the maxillary first molars became unmeasurable during the alignment phase. The reduction in the measurable buccal bone thickness, overlying...