Maria Beatriz Borges de Araújo Magnani

Periodontal and microbiologic evaluation of 2 methods of archwire ligation: ligature wires and elastomeric rings.

INTRODUCTION Prophylactic programs to prevent dental biofilm accumulation must be implemented to minimize the risk for periodontal diseases in orthodontic patients. Therefore, we assessed the possible periodontal and microbiologic changes resulting from the use of 2 methods of orthodontic archwire ligation: elastomeric rings and steel ligatures. METHODS The following parameters were measured: plaque index, gingival bleeding index, probing depth, and biofilm samples from the maxillary second premolars and the mandibular lateral incisors were evaluated in 14 subjects without clinical signs of gingival inflammation before orthodontic appliance placement and after 6 months of treatment. Each orthodontic arch was fixed with elastomeric rings on 1 side of the midline, and steel ligatures were used on the opposite side. Polymerase chain reaction analysis was used to detect Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and P nigrescens. RESULTS The elastomeric rings were associated with a higher score for plaque index and bleeding than steel ligatures, as well as many positive sites of T forsythia and P nigrescens (P <0.05). CONCLUSIONS Elastomeric rings favored these 2 periodontopathogens and harmed gingival conditions.

Shear bond strength of new and recycled brackets to enamel

The purpose of this study was to evaluate in vitro the shear bond strength of recycled orthodontic brackets. S2C-03Z brackets (Dental Morelli, Brazil) were bonded to the buccal surfaces of 50 extracted human premolars using Concise Orthodontic chemically cured composite resin (3M, USA). The teeth were randomly assigned to 5 groups (n=10), as follows. In group I (control), the bonded brackets remained attached until shear testing (i.e., no debonding/rebonding). In groups II, III and IV, the bonded brackets were detached and rebonded after recycling by 90-microm particle aluminum oxide blasting, silicon carbide stone grinding or an industrial process at a specialized contractor company (Abzil-Lancer, Brazil), respectively. In group V, the bonded brackets were removed and new brackets were bonded to the enamel surface. Shear bond strength was tested in an Instron machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukeys test at 5% significance level. There was no statistically significant difference (p>0.05) between the control brackets (0.52 kgf/mm2), brackets recycled by aluminum oxide blasting (0.34 kgf/mm2) and new brackets attached to previously bonded teeth (0.43 kgf/mm2). Brackets recycled by the specialized company (0.28 kgf/mm2) and those recycled by silicon carbide stone grinding (0.14 kgf/mm2) showed the lowest shear strength means and differed statistically from control brackets (0.52 kgf/mm2) (p<0.05). In conclusion, the outcomes of this study showed that bracket recycling using 90-microm aluminum oxide particle air-abrasion was efficient and technically simple, and might provide cost reduction for orthodontists and patients alike.

Craniofacial analysis of the Tweed Foundation in Angle Class II, division 1 malocclusion

This study has defined the cephalometric values of the Craniofacial Analysis of the Tweed Foundation for a sample of Brazilian subjects. The sample consisted of 211 cephalometric radiographs from subjects aged 12-15, which were divided into two groups: Class II group, with 168 lateral teleradiographs (cephalograms) of white Brazilian subjects, with Angle Class II, division 1 malocclusion, of both genders (82 males and 86 females); and the Control Group, with 43 lateral teleradiographs (cephalograms) of subjects whose occlusion was clinically excellent, and also of both genders (21 males and 22 females). The teleradiographs were selected from the files of the Department of Orthodontics, School of Dentistry of Piracicaba, State University of Campinas, previously to the orthodontic treatment. The results demonstrated no sexual dimorphism for each group, as attested by the Students t-test. The exploratory analysis (+/- 0.5 standard deviation) enabled the tolerance limits to be determined and a Craniofacial Analysis Table to be constructed using the respective cephalometric intervals. In addition, the difference between the two groups was not statistically significant according to the maxilla position. The maxilla was in a good position in relation to the cranial base. On the other hand, the mandible was retruded in relation to the cranial base in the Class II cases. The skeletal pattern was not defined because only the Facial Height Index (FHI) showed a vertical pattern in Class II subjects, while the Y Axis, SN.PlO, SN.GoMe and FMA values did not show any statistically significant difference between the groups. The Class II division 1 subjects showed lower incisors more labially tipped and a convex facial profile.

Analysis of the coefficient of variation in shear and tensile bond strength tests

The coefficient of variation is a dispersion measurement that does not depend on the unit scales, thus allowing the comparison of experimental results involving different variables. Its calculation is crucial for the adhesive experiments performed in laboratories because both precision and reliability can be verified. The aim of this study was to evaluate and to suggest a classification of the coefficient variation (CV) for in vitro experiments on shear and tensile strengths. The experiments were performed in laboratory by fifty international and national studies on adhesion materials. Statistical data allowing the estimation of the coefficient of variation was gathered from each scientific article since none of them had such a measurement previously calculated. Excel worksheet was used for organizing the data while the sample normality was tested by using Shapiro Wilk tests (alpha = 0.05) and the Statistical Analysis System software (SAS). A mean value of 6.11 (SD = 1.83) for the coefficient of variation was found by the data analysis and the data had a normal distribution (p>0.05). A range classification was proposed for the coefficient of variation from such data, that is, it should be considered low for a value lesser than 2.44; intermediate for a value between 2.44 and 7.94, high for a value between 7.94 and 9.78, and finally, very high for a value greater than 9.78. Such classification can be used as a guide for experiments on adhesion materials, thus making the planning easier as well as revealing precision and validity concerning the data.

Jarabak 's cephalometric analysis of Brazilian black patients

The treatment of skeletal disharmonies presents better results when performed during the growth period. The physical changes that occur in every individual express growth, which is ruled by genetic, general and environmental factors. In order to identify such disharmonies and hence concentrate the clinical actions during treatment and influence facial growth, cephalometrics appears as a useful a diagnostic tool for identifying facial growth patterns or growth direction. Jarabaks cephalometric analysis is used to assess facial growth pattern of subjects with normal occlusion or malocclusions. The purpose of this study was to obtain mean values for cephalometric measurements from Jarabaks cephalometric analyses of black Brazilian subjects resident in the city of Piracicaba, São Paulo state, Brazil and vicinities, who presented Class I molar relationship with normal overjet and overbite, mild or no tooth crowding or spacing, and no history of orthodontic treatment. A sample of 37 stone plaster casts and 37 lateral teleradiographs from both male and female individuals aged 10 to 14 years was evaluated. Data were analyzed statistically by Students t-test at 5% significance level. There was no significant differences between genders. The cephalometric measurements obtained in this study were similar to the Jarabaks standards, except for S-N mean value in females (66.50 mm +/- 3.16), which was significantly lower than the standard.

Análise in vitro da resistência ao cisalhamento de braquetes metálicos colados em incisivos bovinos e humanos

The purpose of this study was to compare shear bond strength of steel brackets in bovine and human teeth and observe adhesive remnant index (ARI). The sample consisted of thirty teeth, divided into three groups: human permanent lower incisors, bovine permanent lower incisors and bovine deciduous lower incisors. Prophylaxis has been made with pumice and water, followed by enamel acid etching with phosphoric acid at 37% on the surface of the teeth. Steel brackets were bonded with Concise composite according to the manufacturer instructions, and they were submitted to a shear bond strength test for a 0,5 mm / minute speed. The medium values of bond strength in human permanent lower incisors was of x= 12,96 MPa, in bovine permanent lower incisors of x= 15,05 MPa, and bovine deciduous lower incisors of x= 17,03 MPa. There were not significant estatistic differences among the groups, not for strength shear values nor for the evaluation of the ARI.

Cephalometric assessment of vertical control in the treatment of class II malocclusion with a combined maxillary splint

Vertical control is one of the primary objectives sought by orthodontists when treating malocclusions in hyperdivergent individuals. This investigation aimed at assessing vertical control, by cephalometric measurements, during the treatment of Angle Class II Division 1 malocclusion. Thirty cases, selected from the files of the São Leopoldo Mandic Dental Research Center, Brazil, of subjects with Angle Class II Division 1 malocclusion and facial hyperdivergence, were used in this study. The patients were treated using a combined extraoral appliance during a mean treatment time of 1.1 years. Pre- and posttreatment cephalometric measurements were compared to assess vertical control. The results were submitted to ANOVA (p = 5%). The ANOVA test revealed no statistically significant difference between the pretreatment and posttreatment values of OP (Occlusal plane angle) and SN.MP. While there was a decrease in Y-axis, FMA, and PP.MP, there was an increase in SN.PP, Co-Go, AFH, PFH, and FHI. It was concluded that the divergence in the facial lower third of the patients did not increase, suggesting that the combined extraoral appliance with the line of force application directed to the resistance center of the maxilla was effective in treating Angle Class II malocclusion in hyperdivergent subjects.

Oxidação de braquetes metálicos

* Mestre em Ortodontia pela Faculdade de Odontologia de Piracicaba / UNICAMP. Professor do Curso de Especialização em Ortodontia – Efoa / Ceufe. ** Professor Titular da área de Materiais Dentários – Departamento de Odontologia Restauradora da Faculdade de Odontologia de Piracicaba – UNICAMP. *** Professor Titular da área de Materiais Dentários – Departamento de Odontologia Restauradora da Faculdade de Odontologia de Piracicaba – UNICAMP. **** Professora-Doutora da área de Ortodontia – Departamento de Odontologia Infantil da Faculdade de Odontologia de Piracicaba – UNICAMP. ***** Professor Titular da área de Ortodontia – Departamento de Odontologia Infantil da Faculdade de Odontologia de Piracicaba – UNICAMP. que defeitos na estrutura dos mesmos causem danos ao esmalte do paciente. Não é raro observarmos algumas alterações como fraturas, aletas amassadas, separação da malha do restante do braquete, entre outros problemas, porém, cita-se em especial a oxidação da base do braquete (Fig. 1A, B). Quando na cavidade bucal o acessório não é capaz de resistir aos fluidos bucais, liberando substância de cor negra na superfície do esmalte. Diante desta situação, o ortodontista deve A colagem de braquetes diretamente ao esmalte dentário é um procedimento simples, que traz grandes vantagens estéticas ao paciente e benefícios ao profissional. Porém, deve-se usar técnica adequada e criteriosa, respeitando os passos indicados pelos fabricantes. Além disto, deve-se utilizar materiais de qualidade comprovada por pesquisas clínicas e laboratoriais. Na grande maioria das vezes a colagem do braquete é realizada com sucesso, entretanto, esta deve ser verificada durante todo o tratamento com a finalidade de evitar

Cimentação de banda ortodôntica com novo cimento de ionômero de vidro modificado por resina

The aim of this study is to show the orthodontic application of the resin-modified glass ionomer cement Fuji Ortho Band. The clinical sequence of band cementation with this material was explained, being with each step of procedure illustrated, as: band selection and adaptation, prophylaxis and Fuji Ortho Band cement manipulation according to the manufacturers ́ instructions and properly cementation. DescRiptoRs: Glass ionomer cements – Orthodontics. ****** Doutorando em Ortodontia Faculdade de Odontologia de Piracicaba FOP – Universidade Estadual de Campinas UNICAMP; Professor de Ortodontia da Universidade Federal de Alfenas – UNIFAL ****** Professor Titular da área de Materiais Dentários – Faculdade de Odontologia de Piracicaba FOP – Universidade Estadual de Campinas UNICAMP ****** Doutorando em Ortodontia – Faculdade de Odontologia de Piracicaba FOP – Universidade Estadual de Campinas UNICAMP ****** Doutor em Ortodontia – Faculdade de Odontologia de Piracicaba FOP – Universidade Estadual de Campinas UNICAMP; Professor de Ortodontia da Universidade de Ribeirão Preto – UNAERP ****** Professora Doutora da área de Ortodontia – Faculdade de Odontologia de Piracicaba FOP – Universidade Estadual de Campinas UNICAMP ****** Professor Titular de Ortodontia da Faculdade de Odontologia de Piracicaba FOP – Universidade Estadual de Campinas UNICAMP cimentAção De bAnDA oRtoDônticA com novo cimento De ionômeRo De viDRo moDificADo poR ResinA ORthOdOntiC band CimentatiOn with new ReSin-mOdified glaSS iOnOmeR Cement

Resistência ao cisalhamento da colagem com compósitos utilizando potencializador de adesão

OBJECTIVE: The aim of this study was to evaluate the shear bond strength of the Transbond XT and Concise Orthodontics composites using the Ortho Primer adhesion booster. METHODS: The sample consisted of 90 bovine incisors divided in 6 groups (n=15). All teeth were submitted to prophylaxes with pumice stone and etching with phosphoric acid. In Group I the Transbond XT was used conventionally. Group II was similar to Group I, however, Ortho Primer was used instead of XT Primer. In Group III, after the acid etching, the enamel was contaminated with human saliva, the Ortho Primer was applied and bonding was done with Transbond XT. In Group IV Concise Orthodontics was used conventionally. Group V was similar to Group IV, but Ortho Primer was applied instead of fluid resin. In Group VI after acid etching, enamel was contaminated with human saliva, Ortho Primer was applied and bonding was done with Concise. The samples were stored in distilled water in incubator at 37oC for 24h and submitted to the shear strength test. The data were submitted to the ANOVA and the Tukey´s test (5%). RESULTS: Group IV shear bond strength was statistically superior to the Groups II, III and VI (p 0.05). The Concise and Transbond XT used conventionally presented the most high bonding values. The Ortho Primer in dry enamel acted indeed as bonding agent of evaluated composites. The bonding with Concise in contaminated enamel had obtained low adhesive resistance.