Malocclusion prevalence and orthodontic treatment need in central Anatolian adolescents compared to European and other nations' adolescents

Abstract Objective: To determine the prevalence of malocclusion and orthodontic treatment need in a large sample of Central Anatolian adolescents and compare them with European-other nations' adolescents. Methods: The sample included 1125 boys and 1204 girls aged between 12 and 16 years with no previous orthodontic treatment history. Occlusal variables examined were molar relationship, overjet, overbite, crowding, midline diastema, posterior crossbite, and scissors bite. The dental health (DHC) and aesthetic components (AC) of the Index of Orthodontic Treatment Need (IOTN) were used as an assessment measure of the need for orthodontic treatment for the total sample. Results: The results indicated a high prevalence of Class I (34.9%) and Class II, Division 1 malocclusions (40.0%). Moreover, increased (18%) and reduced bites (14.%), and increased (25.1%) and reversed overjet (10.%) were present in the sample. Conclusion: Using the DHC of the IOTN, the proportion of subjects estimated to have great and very great treatment need (grades 4 and 5) was 28.%. However, only 16.7% of individuals were in need (grades 8-10) of orthodontic treatment according to the AC.

Resumo Objetivo: determinar a prevalência de má oclusão e a necessidade de tratamento ortodôntico em uma amostra extensa de adolescentes da Anatólia Central, e compará-los a adolescentes europeus de outras nacionalidades. Métodos: a amostra consistiu de 1125 meninos e 1204 meninas, com idades entre 12 e 16 anos, sem histórico de tratamento ortodôntico prévio. As variáveis oclusais avaliadas foram a relação entre molares, overjet,overbite, apinhamento, diastema na linha média, mordida cruzada posterior e mordida em tesoura. O Componente de Saúde Dental (DHC) e o Componente Estético (AC) do Índice de Necessidade de Tratamento Ortodôntico (IOTN) foram utilizados para avaliar a necessidade de tratamento ortodôntico de toda a amostra. Resultados: os resultados sugerem uma alta prevalência de má oclusão de Classe I (34,9%) e Classe II, subdivisão 1 (40,0%). Além disso, overbiteaumentado (18,3%) e reduzido (14,4%), e overjet aumentado (25,1%) e reduzido (10,4%) também foram observados na amostra. Conclusão: com base no uso do DHC do IOTN, observou-se que a proporção dos indivíduos avaliados com necessidade grande e muito grande de tratamento (notas 4 e 5) foi de 28,7%. Porém, de acordo com o AC, apenas 16,7% dos indivíduos apresentaram necessidade (notas 8-10) de tratamento ortodôntico.

Effects of silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets

OBJECTIVE: The aim of this study was to evaluate the effects of tribochemical silica coating and silane surface conditioning on the bond strength of rebonded metal and ceramic brackets. MATERIAL AND METHODS: Twenty debonded metal and 20 debonded ceramic brackets were randomly assigned to receive one of the following surface treatments (n=10 for each group): (1) sandblasting (control); (2) tribochemical silica coating combined with silane. Brackets were rebonded to the enamel surface on the labial and lingual sides of premolars with a light-polymerized resin composite. All specimens were stored in distilled water for 1 week and then thermocycled (5,000 cycles) between 5-55ºC. Shear bond strength values were measured using a universal testing machine. Student's t-test was used to compare the data (α=0.05). Failure mode was assessed using a stereomicroscope, and the treated and non-treated bracket surfaces were observed by scanning electron microscopy. RESULTS: Rebonded ceramic brackets treated with silica coating followed by silanization had significantly greater bond strength values (17.7±4.4 MPa) than the sandblasting group (2.4±0.8 MPa, P<0.001). No significant difference was observed between the rebonded metal brackets treated with silica coating with silanization (15±3.9 MPa) and the sandblasted brackets (13.6±3.9 MPa). Treated rebonded ceramic specimens primarily exhibited cohesive failure in resin and adhesive failure at the enamel-adhesive interface. CONCLUSIONS: In comparison to sandblasting, silica coating with aluminum trioxide particles followed by silanization resulted in higher bond strengths of rebonded ceramic brackets.