ABSTRACT
Abstract The objective of the present study was to evaluate the effect of different surface treatments and polymerization protocols on the bond strength of brackets to enamel, and the degree of conversion of the bonding agents. 120 bovine crowns were embedded in acrylic resin blocks and sanded. Next, the blocks were randomly assigned into 12 groups. Metal brackets were bonded to enamel according to the "surface treatment" factor (A: Phosphoric Acid; ATxt: Phosphoric Acid + Transbond XT Primer®; Tse: Transbond Plus Self Etching Primer®; and SBU: Scotchbond Universal®) and "polymerization" factor (R20: Radii-Cal®/20 seconds; V20: Valo Cordless®/20 seconds; and V3: Valo Cordless®/3 seconds). All samples were stored for 6 months (water, 37ºC) and then subjected to a shear bond strength test (SBS). Bond failures were classified according to the Adhesive Remnant Index (ARI) and analyzed with the Kruskal-Wallis and Mann-Whitney tests (5%). Using the same factors, 120 resin discs were made to assess the degree of conversion (DC) of the monomer. Data from the SBS (MPa) and DC (%) were analyzed by analysis of variance (2 factors) and Tukey's test (5%). For the SBS, the factors "polymerization" (R20 = 8.1B; V20 = 13.2A; V3 = 5.2C, p = 0.0001) and "surface treatment" (A = 3.1C; ATxt = 13.6A; Tse = 12.3A; SBU = 6.3B, p = 0.0001) were statistically significant among groups. The highest adhesion value were found for the ATxt/V20 group (22.2A) and the lowest value for the A/R20 group (1.2E). Regarding ARI, score 2 was the most prevalent in groups A, ATxt, V20 and V3, while score 4 was the most prevalent in the Tse, SBU and R20 groups, with no significant difference between them (p = 1.0). Regarding DC, the factors "polymerization" (R20 = 66.6A; V20 = 58.4B; V3 = 45.1C, p = 0.0001) and "surface treatment" (A = 52B, ATxt = 59.7A, Tse = 51.4B, SBU = 63.8A, p = 0.0001) were statistically significant. Tse was more sensitive to the variations in polymerization protocols than the other surface treatments. Treatment A did not present suitable bond strength or degree of conversion.
Subject(s)
Animals , Cattle , Orthodontic Brackets , Resin Cements/chemistry , Dental Enamel/drug effects , Self-Curing of Dental Resins/methods , Light-Curing of Dental Adhesives/methods , Polymerization/drug effects , Phosphoric Acids/chemistry , Reference Values , Time Factors , Acid Etching, Dental/methods , Materials Testing , Random Allocation , Adhesiveness/drug effects , Reproducibility of Results , Analysis of Variance , Dental Enamel/chemistry , Shear Strength , Phase Transition , Curing Lights, DentalABSTRACT
Objetivo: Avaliar o efeito de diferentes tratamentos de superfície na resistência de união de bráquetes metálicos colados ao esmalte e no grau de conversão dos agentes de colagem, utilizando diferentes protocolos de polimerização. Metodologia: Cento e vinte coroas dentárias de incisivos bovinos foram incluídas em blocos de resina acrílica, lixadas e distribuídas aleatoriamente em 12 grupos. Em seguida, bráquetes metálicos foram colados no esmalte planificado de acordo com os fatores "tratamento de superfície" (A-ácido fosfórico, ATxt-ácido fosfórico+primer Transbond XT®/3M, Tse-Transbond Plus Self Etching Primer®/3M e SBU-Single Bond Universal®/3M) e "polimerização" (R20-Radii-Cal®/20 segundos, V20-Valo Cordless®/20 segundos e V3-Valo Cordless®/3 segundos). As amostras foram armazenadas por 6 meses (água, 370C) e, depois, submetidas ao ensaio de resistência de união cisalhamento (RUC), 300KgF, 1mm/min. Utilizando os mesmos protocolos do ensaio anterior, 120 discos de resina foram confeccionados para análise do grau de conversão (GC). Os dados da RUC (MPa) e do GC (%) foram analisados pelo ANOVA (2 fatores) e Teste de Tukey (5%). As falhas foram classificadas de acordo com o Índice Remanescente Adesivo (IRA) e avaliadas através dos testes Kruskal-Wallis e Mann-Whitney (5%). Resultados: Para a RUC, os fatores "polimerização" (R20=8,146B; V20=13,271A; V3=5, 26C, p=0.0001) e "tratamento de superfície" (A=3,18C ; ATxt=13,63A; Tse=12,38A; SBU=6,37B, p=0.0001) mostraram-se estatisticamente significantes. Os maiores valores de adesão foram encontrados para o grupo ATxtV20 (22,298A) e os menores, para o grupo AR20 (1,27E). Quanto ao IRA, o escore 2 foi o mais prevalente nos grupos A, ATxt, V20 e V3, enquanto que o escore 4 foi o mais prevalente nos grupos Tse, SBU e R20, sem diferença significante entre eles (p=1,0). No que diz respeito ao GC, os fatores "polimerização" (R20=66,67A ; V20=58,48B ; V3=45,12C, p=0.0001) e "tratamento de superfície" (A=52,01B, ATxt=59,71A, Tse=51,47B, SBU=63, 84A, p=0.0001) mostraram-se estatisticamente significantes. Conclusões: O Tse mostrou-se mais sensível às variações nos protocolos de polimerização do que os outros tratamentos de superfície. Já o tratamento A não apresentou valores de RUC e GC adequados para a colagem de bráquetes metálicos ao esmalte (AU)
Objective: To evaluate the effect of different surface treatments and polymerization protocols on the bond strength of brackets to enamel, and the degree of conversion of the bonding agents. Methods: 120 bovine crowns were embedded in acrylic resin blocks and sanded. Next, the blocks were randomly assigned into 12 groups. Metal brackets were bonded to enamel according to the "surface treatment" factor (A: Phosphoric Acid; ATxt: Phosphoric Acid + Transbond XT Primer®; Tse: Transbond Plus Self Etching Primer®; and SBU: Scotchbond Universal®) and "polymerization" factor (R20: Radii-Cal®/20 seconds; V20: Valo Cordless®/20 seconds; and V3: Valo Cordless®/3 seconds). All samples were stored for 6 months (water, 37ºC) and then subjected to a shear bond strength test (SBS). Using the same factors, 120 resin discs were made to assess the degree of conversion (DC) of the monomer. Data from the SBS (MPa) and DC (%) were analyzed by analysis of variance (2 factors) and Tukey's test (5%). Bond failures were classified according to the Adhesive Remnant Index (ARI) and analyzed with the Kruskal-Wallis and Mann-Whitney tests (5%). Results: For the SBS, the factors "polymerization" (R20=8.1B; V20=13.2A; V3=5.2C, p=0.0001) and "surface treatment" (A=3.1C; ATxt=13.6A; Tse=12.3A; SBU=6.3B, p=0.0001) were statistically significant among groups.The highest adhesion value were found for the ATxtV20 group (22.2A) and the lowest value for the A/R20 group (1.2E). Regarding ARI, score 2 was the most prevalent in groups A, ATxt, V20 and V3, while score 4 was the most prevalent in the Tse, SBU and R20 groups, with no significant difference between them (p=1.0). Regarding DC, the factors "polymerization" (R20=66.6A; V20=58.4B; V3=45.1C, p=0.0001) and "surface treatment" (A=52B, ATxt=59.7A, Tse=51.4B, SBU=63.8A, p=0.0001) were statistically significant. Conclusions: Tse was more sensitive to the variations in polymerization protocols than the other surface treatments. Treatment A did not present suitable bond strength or degree of conversion (AU).
Subject(s)
Animals , Cattle , Adhesiveness , Orthodontic Brackets , Dental Enamel , Shear Strength , Polymerization , Orthodontics , Acrylic Resins , Analysis of Variance , Statistics, Nonparametric , Dental MaterialsABSTRACT
ABSTRACT Objective: To evaluate the agreement between cephalometric measures obtained from two different software programs: Dolphin Imaging 11.7® and Radiocef Studio 2® . Methods: 30 digital lateral teleradiographies (200 dpi, 2100 x 2092 pixels) were analyzed on each of the software programs through demarcation of 11 cephalometric points by a single calibrated examiner. Then, the generated cephalometric magnitudes were statistically correlated by means of the intraclass correlation coefficients (ICC). Then 10 randomly selected radiographies were retraced on each of the programs in order to evaluate the intra-examiner concordance after a time interval of 08 days. Results: The SNB and Pog-NB magnitudes showed strong concordance between the software, while the SNA, ANB, 1-NA, 1-NB, 1.NB, 1.1 and Go-Gn.SN magnitudes unveiled moderate concordance. Only the 1.NA magnitude showed weak concordance. Conclusion: The software can be interchangeably applied in clinical practice.
RESUMO Objetivo: Avaliar a concordância entre grandezas cefalométricas obtidas através dos softwares Dolphin Imaging 11.7® e Radiocef Studio 2® . Métodos: Trinta telerradiografias laterais digitais (200 dpi, 2100 x 2092 pixels) foram analisadas em cada um dos softwares através da demarcação de 11 pontos cefalométricos por um único examinador calibrado. As grandezas cefalométricas geradas foram correlacionadas estatisticamente por meio dos coeficientes de correlação intra classe (CCI). A fim de avaliar a concordância intra-examinador, 10 telerradiografias selecionadas aleatoriamente foram retraçadas em cada um dos softwares após um intervalo de 8 dias. Resultados: As grandezas SNB e Pog-NB mostraram forte concordância entre os softwares, enquanto que as grandezas SNA, ANB, 1-NA, 1-NB, 1.NB, 1.1 e Go-Gn.SN revelaram concordância moderada. Somente a grandeza 1.NA demonstrou fraca concordância. Conclusão: Os softwares podem ser aplicados intercambiavelmente na prática clínica.
ABSTRACT
ABSTRACT OBJECTIVE: This study aims at comparing the perception of orthodontists, maxillofacial surgeons, visual artists and laypersons when evaluating the influence of sagittal position of the mandible - in lateral view - in facial attractiveness; at a job hiring; and in the perception of socioeconomic profile. METHODS: A black male, a white male, a black female and a white female with harmonic faces served as models to obtain a facial profile photograph. Each photograph was digitally manipulated to obtain seven facial profiles: an ideal, three simulating mandibular advancement and three simulating mandibular retrusion, producing 28 photographs. These photographs were evaluated through a questionnaire by orthodontists, maxillofacial surgeons, visual artists and laypersons. RESULTS: The anteroposterior positioning of the mandible exerted strong influence on the level of facial attractiveness, but few significant differences between the different groups of evaluators were observed (p < 0.05). CONCLUSIONS: The profiles pointed as the most attractive were also pointed as more favorable to be hired to a job position and pointed also as having the best socioeconomic condition.
RESUMO OBJETIVO: a presente pesquisa teve por objetivo comparar a percepção de ortodontistas, cirurgiões bucomaxilofaciais, artistas visuais e leigos ao avaliar a influência do posicionamento sagital da mandíbula, em vista lateral, na atratividade facial; na contratação para um emprego; e na percepção do perfil socioeconômico. MÉTODOS: um homem negro, um homem branco, uma mulher negra e uma mulher branca com faces harmoniosas serviram como modelos para obtenção de fotografias do perfil facial. Cada fotografia obtida foi digitalmente manipulada para a obtenção de sete perfis faciais: um ideal, três simulando avanço mandibular e três simulando retrusão mandibular, originando 28 fotografias. Essas fotografias foram avaliadas, por meio de um questionário, por quatro grupos de avaliadores: ortodontistas, cirurgiões bucomaxilofaciais, artistas visuais e leigos. RESULTADOS: o posicionamento anteroposterior da mandíbula exerceu forte influência sobre o grau de atratividade facial, porém foram observadas poucas diferenças significativas entre os diferentes grupos de avaliadores (p < 0,05). CONCLUSÕES: os perfis apontados como mais atraentes foram, também, os mais apontados como favoráveis à contratação para um emprego e os mais apontados como aqueles que aparentavam melhor condição socioeconômica.
Subject(s)
Humans , Male , Female , Social Perception , Esthetics, Dental/psychology , Face/anatomy & histology , Mandible/anatomy & histology , Retrognathia , Social Class , Social Values , Brazil , Ethnicity , Surveys and Questionnaires , Analysis of Variance , Mandibular Advancement , Photography, Dental , Oral and Maxillofacial Surgeons/psychology , Orthodontists/psychology , LipABSTRACT
Comparou-se a percepção de ortodontistas, cirurgiões bucomaxilofaciais, artistas visuais e leigos ao se avaliar a influência do posicionamento sagital da mandíbula, em vista lateral, na atratividade facial; na decisão pelo tratamento ortodôntico-cirúrgico em outra pessoa; e na decisão pelo tratamento ortodôntico-cirúrgico em si próprio. Um homem negro, um homem branco, uma mulher negra e uma mulher branca com faces harmônicas serviram como modelos para obtenção de uma fotografia de perfil facial. Cada fotografia foi digitalmente manipulada para a obtenção de sete perfis faciais: um ideal, três simulando avanço mandibular e três simulando retrusão mandibular, originando 28 fotografias. Essas fotografias foram avaliadas através de um questionário por 4 grupos de examinadores: ortodontistas, cirurgiões bucomaxilofaciais, artistas visuais e leigos. Concluiu-se que o posicionamento anterior da mandíbula exerceu forte influência sobre o nível de atratividade facial, porém foram observadas poucas diferenças significativas entre os grupos de avaliadores (p<0,05).
This research aimed to compare the perception of orthodontists, maxillofacial surgeons, visual artists, and laypeople when evaluating, from a lateral view, the influence of mandibular sagittal position on facial attractiveness; and their perception regarding the requirement of orthodontic-surgical treatment need for yourself or another person. Profile photographs were taken from a black male, a white male, a black female and a white female with harmonic faces. Each photograph was digitally manipulated to obtain seven facial profiles: an ideal profile, three simulating mandibular advancement, and three simulating mandibular retrusion, resulting on 28 photographs. These photographs were evaluated through a questionnaire by orthodontists, maxillofacial surgeons, visual artists, and laypersons. It was concluded that the anteroposterior positioning of the mandible exerted a strong influence on the level of facial attractiveness, but few significant differences between the different groups of evaluators were observed (p<0.05).