Avaliação da resistencia ao cisalhamento da resina composta e do cimento de ionomero de vidro na fixação de braquetes metalicos

Orientador: Darcy Flavio Nouer, Simonides ConsaniTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O objetivo desta pesquisa foi avaliar a resistência ao cisalhamento da resina composta e do cimento de ionômero de vidro na fixação de diferentes tipos - de bráquetes metálicos (Morelli, Abzil-Lancer, Dentaurum e GAC). Foram utilizados 120 pré-molares humanos. As faces vestibulares de 80 prémolares receberam condicionamento ácido e os bráquetes foram fixados utilizando Concise Ortodôntico e Transbond XT, enquanto em outros 40 prémolares, os bráquetes foram fixados com Fuji Ortho LC. As amostras foram armazenadas em solução de soro fisiológico a 0,9% a 37°C por 24 horas. Em seguida, foram submetidas ao teste de resistência ao cisalhamento em uma máquina Instron, com velocidade de 0,5mm/min. Os resultados foram submetidos à análise de variância e ao teste de Tukey (p<0,05). Associando sistemas adesivos aos respectivos bráquetes, os resultados mostraram que: a) com o Concise ortodôntico, a resistência (kgf/mm 'POT. 2¿)do bráquete GAC (1,698) foi significantemente maior que os bráquetes Abzil-Lancer (1,353), Dentaurum (1,293) e Morelli (0,828), que apresentou a menor média; b) com o Transbond XT, observou-se que os bráquetes Dentaurum (1,082) e GAC (1,225) apresentaram médias significantemente maiores do que os bráquetes Morelli (0,583) e Abzil-Lancer (0,621); e, c) com o Fuji Ortho LC, não foram observadas diferenças entre as médias dos diferentes bráquetes testados (Morelli=0,301, Abzil-Lancer=0,309, Dentaurum 0,230 e GAC=0,338). Os autores concluíram que o Concise Ortodôntico apresentou maiores valores de resistência ao cisalhamento, seguidos do Transbond XT e Fuji Ortho LC. O bráquete GAC apresentou maior resistência em todos os materiais e o bráquete Morelli a menor resistênciaAbstract: The aim of this study was to evaluate the shear bond strength of composites and glass ionomer cement of different metallic brackets bonding (Morelli, Abzil-Lancer, Dentaurum e GAC). One hundred and twenty human premolars were used. For eighty premolars, the vestibular faces were etched and were bonded to enamel surface using Concise Ortho and Transbond XT, whereas in others forty premolars the brackets were bonded with Fuji Ortho LC in the vestibular faces without acid etching. All samples were stored in fisiologic solution 0,9% at 37°C for 24 hours. Afier the sample were submitted to shear bond strength in an Instron at a crosshead speed of 0.5 mm/min. The results were submitted to ANOVA and Tukey's test (p<0.05). Associating adhesives systems to respective brackets, the data indicated that: a) with Concise Ortho, the strengths (kgt/mm¿POT. 2¿) of GAC bracket (1.698) was significant1y higher than Abzil-Lancer (1.353), Dentaurum (1.293) and Morelli (0.828) brackets; b) with Transbond XT, Dentaurum (1.082) and GAC (1.225) brackets showed average higher than Morelli (0.583) and Abzil-Lancer (0.621); and, c) with Fuji Ortho LC, it wasn't showed difference between the average of different brackets tested (Morelli=0.301, Abzil-Lancer=0.309, Dentaurum 0.230 and GAC=0.338). The authors concluded that the Concise Ortho showed highest shear bond strength values followed by Transbond XT and Fuji Ortho LC. The GAC bracket showed higher strength in alI adhesives systems and the Morelli bracket the lowest strengthDoutoradoDoutor em Ortodonti

Evaluation of the face and dental morphologic alterations in adult individuals with labial incompetence

Objective: To evaluate certain facial and dental characteristics by comparing individuals with labial incompetence and individuals withpassive labial sealing. Method: The study analyzed fifty lateral teleradiographs of which 25 were of subjects with labial incompetence, with minimum opening of 4 mm, and 25 of subjects with labial sealing, none of the subjects having undergone orthodontic treatment, all being between 15 and 30 years of age, irrespective of gender and malocclusion, with slight tendency towards vertical growth. The following cephalometric variables were used: Nfp – Nfa with the objective of determining the width of the upper airway, Sn – St to measure the length of the upper lip, Sn –IIs for the vertical length of the maxilla and 1.NA to determine the inclination of the maxillary incisor. Results: The measurements obtained in the group of passive lip sealing (G1) and labial incompetence (G2) respectively, were as follows: 14.12 mm (G1) and 12.76 mm (G2) for width of the upper airway; 24.24 mm (G1) and 23.80 mm (G2) for the length of the upper lip; 26.92 mm (G1) and 28.64 mm (G2) for the vertical length of the maxilla and 26.76º (G1) and 30.76º (G2) for the inclination of themaxillary incisor. Conclusion: The results allowed one to conclude that the individual with labial incompetence presented width of the upper airway similar to that of the individual with passive lip sealing. Individuals with labial incompetence presented increased vertical length of the maxilla and not shortening of the upper lip. The presence of vestibularized maxillary incisors is a condition inherent to the subject with labial incompetence, who will consequently present hypotonicity of the upper lip

The orthodontist’s civil responsibility post-orthodontic therapy

Objective: The aim of this work was to investigate what the orthodontist’s difficulties are, analyzing whether the adopted procedures are able to satisfy the complaints of individuals, who already concluded orthodontic therapy, according to the determinations of the civil code and the Costumer’s Defense Code, as well as the relationship between patient and professional. Methods: A questionnaire was sent by postal service to all the odonthology specialists inrolled in the CRO/RJ amounting to 990 professionals.Results: The percentual analysis of the analysis showed that 96.9% of them adopt some pattern of kind of contract. The majority (65.8%)regards the orthodontist’s Civil Responsibility as a result. In case of reincident postrentation, 87.2% of the professionals inform the individual that it’s possible and also propose them orthodontic re-treatment. Concerning the conduct adopted by the orthodontist towards the individual’s dissatisfaction, 76.5%, anyhow, try to avoid a lawsuit. Conclusion: Some professionals may be subject to future court problems, there was wide divergence between professionals in relation to the time of filing of the orthodontic documentation and there was a relative same opinion of professionals in making an oversight of the patient in the period post-restraint

Surface properties of composite resins with and without fluorides for bracket bonding / Propriedades de superfície de resinas compostas com e sem fluoretos para colagem de suportes

The aim of this study was to evaluate the surface properties of orthodontic resins with and without fluoride. Forty disks, measuring 2 mm thick by 6 mm in diameter, were made of 4 bracket-bonding composite resins (n=10): Transbond Plus Color Change-3M/Unitek (TPCC); Transbond XT- 3M/Unitek (TXT), Orthocem -FGM (OC); Orthocem UV Trace-FGM (OCUV). The discs were photoactivated for 40 seconds with irradiance of 450 mW/cm2 and manually polished in sequence by silicon carbide sandpapers with 1200 and 2000 grain size and finished with diamond paste and felt disc. The surface microhardness analysis was performed using a Shimadzu Micro Hardness Tester HMV-2,000 (Shimadzu Corporation, Kyoto, Japan) with a load of 50 gF and a 5 second penetration time. Surface roughness readings were taken using a Surf Corder Roughness Meter (SE 1700- Kosaka, Lisboa-Portugal). For data analysis, ANOVA (one-way) was used, followed by Tukey's post-test (?=0.05). The microhardness results showed a difference (p?0.05) in the means of the orthodontic resins between TPCC and TXT with the other groups. After the surface roughness analysis, the averages showed that TPCC resin showed higher roughness compared to OC and OCUV (p?0.05), and there was no statistical difference with TXT. It was concluded that statistically the composite resins with fluoride showed significant difference regarding hardness and roughness

Color change and force degradation of esthetic orthodontic elastic ligatures submitted to foods from the Amazonian diet/ Alteração de cor e degradação de forças de ligaduras elásticas ortodônticas estéticas submetidas a alimentos da dieta amazonense

The aim was to evaluate the color changes (?E*) and force degradation (FD) of esthetic elastic ligatures when submitted to foods from the Amazonian diet. 150 segments of elastics (n=10) (American Orthodontics - AO Orthoclassic - OC and Orthometric - OM) were divided to be submitted 2 times a day, for 1min each immersion, for 28 days, in one of the solutions: AI- açaí, CU- cupuaçu, TU- tucumã, RW- red wine and DW- distilled water (control). FD was evaluated using a universal testing machine and ?E* by spectrophotometer. Qualitative analyses were performed by scanning electron microscopy (SEM). The readings were taken at the following times: T0 - initial, T1 - 24 hours, T2 - 14 and T3 - 28 days. The FD and ?E* data were analyzed by non-parametric statistics (p&lt;0.05). It was found that in the 3 brands, in all substances, there was a significant decrease in strength at T1 and at T2 there was an increase in strength. At T3, it is found that CU and DW promote significant differences from AI to OM and OC. For ?E* it was verified after 28 days in OM the ?E* was higher for the elastics submitted to TU and RW than in CU and DW. For OC, the variation was greater in DW than for TU and AI, whereas for AO there was no significant difference between the groups.  for all brands there is a higher FD in the first 24 hours, with elastic recovery after this period; all solutions promote FD in the evaluated elastics and, for all brands tested, the ?E* is clinically unacceptable after 28 days of immersion

Avaliação radiografica dos incisivos centrais superiores frente a movimentação ortodontica : (estudo da reabsorção radicular externa apical)

Orientadores: Darcy Flavio Nouer, Alexandre Augusto ZaiaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A presente pesquisa teve o objetivo de avaliar, radiograficamente, a média e a freqüência da reabsorção radicular externa apical, correlacionando com a movimentação ortodôntica, bem como avaliar a presença de dimorfismo sexual, em 100 incisivos centrais superiores, de 50 pacientes, sendo 25 do sexo masculino e 25 do sexo feminino, leucodermas, portadores de maloclusão Classe II, divisão I de Angle. Os pacientes foram tratados pela técnica de Edgewise, Filosofia de Tweed, e todos os tratamentos envolveram extrações dos primeiros pré-molares. Para a análise estatística foram utilizados: a) teste t de Student; b) teste de regressão linear; c) coeficiente de correlação de Pearson e d) estatística das ordens assinaladas. Concluiu-se, frente os resultados obtidos, que: 1. A freqüência da reabsorção radicular externa apical nas classes de 1 a 2mm e 2 a 3 mm foi 46% e 44%, respectivamente, representando 90% do experimento; 2. A média de reabsorção radicular externa apical no sexo feminino foi de 2,19mm e no sexo masculino de 1,83mm, sendo verificada, portanto, a presença de dimorfismo sexual; 3. Os movimentos de retração e intrusão predispõem mais a reabsorção radicular externa apical do que o movimento de torque, embora todos tenham sido estatisticamente significantes. 4. A reabsorção radicular verificada neste estudo não comprometeu a estabilidade e longevidade dos dentes analisados, sendo clinicamente irrelevanteAbstract: This present study analysed, by lateral cephalograms and periapical x-ray films, the average and frequency of external apical root resorption, correlationing to orthodontic movement, as well as avalue the sexual dimorphism, in 100 upper central incisors, of 50 patients (25 male and 25 female), with malocclusion Class II, division 1. All the patients were treated by Edgewise technique, Tweed Philosophy, and all treatments envolved extraction of first premolars. For the statistic analysis we used Student t test; linear regression test, Pearson test and a non parametric test. From these data, we conclued that: 1. External apical root resorption frequency between 1 to 2mm and 2 to 3 mm were 46% and 44%, representing 90% of this present study; 2. The average of external apical root resorption in girls and boys were 2,19mm and 1,83mm, was noted the sexual dimorphism; 3. Distal body retraction and incisor intrusion were more predictive of external apical root resorption then torque movement, although all of them were statistic significant. 4. Root resorption analysed in this study didn't compromise the stabilíty and longevity of the examined teeth, being irrelevant in the clinicMestradoOrtodontiaMestre em Odontologi

Evaluation of friction in metal, ceramic and self-ligating brackets submitted to sliding mechanics

Abstract Objective With the purpose of evaluating the best results for a proposed orthodontic treatment, the aim of this research was to verify the frictional force between archwires and orthodontic brackets in sliding mechanics. Material and method Three different types of brackets were used: conventional metal, self-ligating metal and conventional polycrystalline esthetic type (n=10), totaling 30 brackets and .019 x .025 inches stainless steel rectangular wire. An acrylic plate was used. The wire was fixed to the brackets (conventional metal and conventional polycrystalline esthetic) with esthetic elastomeric ligation. The acrylic plate together with the 019 x 0.025 inches wire fitted to it was attached to the base plate of the Instron 4411 universal test machine so that it was positioned perpendicular to the ground. The bracket was drawn through the archwire segment at a speed of 5 mm / minute for a distance of 5 mm. For each type of bracket, ten tests were performed, with the bracket and archwire set being changed for each repetition. Data were analyzed by one-way Analysis of Variance (p 0.05), while ceramic bracket presented higher frictional resistance during sliding test (p<0.05). Conclusion It was concluded that the type of bracket influenced the frictional force value obtained, and better results were found when the metal and self-ligating brackets were used. The ceramic bracket presented a higher frictional force value

Influence of bleaching and desensitizing gel on bond strength of orthodontic brackets

OBJECTIVE: The objective of this study was to assess, in vitro, the influence of bleaching gel and the use of desensitizing agent over bond strength of ceramic brackets bonded to bovine enamel. METHODS: One hundred bovine incisors were selected and randomly divided into five groups (n = 20): Group 1, control group (without bleaching); Group 2, bleached with 35% hydrogen peroxide; Group 3, bleached with 35% hydrogen peroxide (three applications, 15 minutes each) and desensitizing agent applied for 10 minutes; Group 4, bleached with 35% hydrogen peroxide for 40 minutes; Group 5, bleached with 35% hydrogen peroxide for 40 minutes with desensitizing agent applied for 10 minutes. Brackets were bonded 7 days after bleaching and submitted to shear bond strength test after 24 hours at a compression rate of 1 mm/minute. After fracture, the adhesive remnant index (ARI) was assessed under stereoscopic at 40 x magnification. Shear strength data (MPa) were submitted to one-way ANOVA and Tukey's test with significance level set at 5%. RESULTS: Group 5 (29.33 MPa) showed significantly higher bond strength than Group 1 (19.19 MPa), Group 2 (20.59 MPa) and Group 4 (23.25 MPa), but with no difference in comparison to Group 3. There was no significant difference among the other groups. The adhesive remnant index showed predominance of score 3, that is, all resin remained adhered to enamel for all groups. CONCLUSION: Bleaching with 35% hydrogen peroxide with calcium associated with desensitizing agent application produced higher bond strength values of brackets bonded to bovine enamel

Changes in pharyngeal airway space and soft tissue after maxillary advancement and bimaxillary surgery

AIM:To evaluate changes in pharyngeal airway space (nasopharynx and oropharynx), soft palate and lingual vallecula after maxillary advancement surgery and maxillary advancement and mandibular setback surgery (bimaxillary surgery).METHODS:Twenty Class III adult patients were included in the study. Ten patients were treated with maxillary advancement and ten with bimaxillary surgery (maxillary advancement and mandibular setback). Cephalometric landmark measurements were recorded at 3 different time intervals: pre-surgical, post-surgical and six months after surgery. Data collected were subjected to one-way ANOVA (p<0.05).RESULTS: Nasopharyngeal airway space increased after maxillary advancement and decreased after bimaxillary surgery. There was increase in oropharyngeal dimensions in the region around the uvula and loss of space for lingual vallecula, while in Group 2 there was diminished space for both uvula and vallecula. The uvula and vallecula were moved forward in Group 1, whereas these structures were moved in the posterior direction in Group 2.CONCLUSIONS: After maxillary advancement surgery there was an increased in space in the nasopharyngeal region. The oropharyngeal region related to the uvula presented an increase in space, whereas there was a reduction in relation to the lingual vallecula. The uvula and lingual vallecula were moved forward. Bimaxillary surgery promoted a reduction in the nasopharyngeal and oropharyngeal regions as regards both the uvula and lingual vallecula. The uvula and lingual vallecula were moved in the posterior direction