Pre-emptive Intracoronal Radiolucency in First Permanent Molar.

Pre-eruptive intracoronal radiolucency (PECR) is characterized by the existence of a radiographic radiolucent area inside the coronal dentin prior to dental eruption. It is a rare clinical entity of unknown etiology, usually asymptomatic and diagnosed through routine radiographs. The aim of this article is to report the treatment of a PECR in an 8-year-old girl. Surgical procedure to expose the crown was conducted; upon tooth eruption, the radiolucent lesion was accessed and the tooth was restored. The case has an 18-month follow-up and emphasis on aspects linked to diagnosis and clinical approach was discussed. How to cite this article: Ilha MC, Kramer PF, Ferreira SH, Ruschel HC. Pre-eruptive Intracoronal Radiolucency in First Permanent Molar. Int J Clin Pediatr Dent 2018;11(2):151-154.

Evaluation of fracture torque resistance of orthodontic mini-implants.

This study sought to assess the fracture torque resistance of mini-implants used for orthodontic anchorage. Five commercially available brands of mini-implants were used (SIN®, CONEXÃO®, NEODENT®, MORELLI®, andFORESTADENT®). Ten mini-implants of each diameter of each brand were tested, for a total 100 specimens. The mini-implants were subject to a static torsion test as described in ASTMstandard F543. Analysis of variance (ANOVA) with the Tukey multiple comparisons procedure was used to assess results. Overall, mean fracture strength ranged from 15.7 to 70.4 N·cm. Mini-implants with larger diameter exhibited higher peak torque values at fracture and higher yield strength, regardless of brand. In addition, significant differences across brands were observed when implants were stratified by diameter. In conclusion, larger mini-implant diameter is associated with increased fracture torque resistance. Additional information on peak torque values at fracture of different commercial brands of mini-implants may increase the success rate of this orthodontic anchorage modality.

O objetivo do presente estudo foi avaliar a resistência de fratura ao torque de miniimplantes ortodônticos. Foram utilizadas cinco marcas comerciais (SIN®, CONEXÃO®, NEODENT®, MORELLI® e FORESTADENT®). Para cada diâmetro, de cada marca comercial, foram testados 10 miniimplantes, totalizando 100 amostras. Os miniimplantes foram submetidos a um Ensaio Estático de Torção, conforme a norma técnica ASTM F543. Os resultados foram submetidos à Análise de Variância (ANOVA) complementado pelo teste de comparações múltiplas de Tukey. Os valores médios de resistência de fratura ao torque variaram de 15,7 a 70,4 N·cm e miniimplantes de maior diâmetro apresentaram maiores valores de torque máximo de fratura e de limite de escoamento, independente da marca comercial. Além disso, foram observadas diferenças significativas entre as marcas comerciais quando agrupadas de acordo com o diâmetro. Conclui seque miniimplantes de maior diâmetro apresentaram maiores valores de resistência de fratura ao torque. Informações sobreo torque máximo de fratura das diferentes marcas comerciais podem aumentar o índice de sucesso deste método de ancoragem ortodôntica.

Evaluation of fracture torque resistance of orthodontic mini-implants / Resistência de fratura ao torque de mini-implantes ortodônticos

This study sought to assess the fracture torque resistance of miniimplants used for orthodontic anchorage. Five commercially available brands of miniimplants were used (SIN®, CONEXÃO®, NEODENT®, MORELLI®, and FORESTADENT®). Ten miniimplants of each diameter of each brand were tested, for a total 100 specimens. The miniimplants were subject to a static torsion test as described in ASTM standard F543. Analysis of variance (ANOVA) with the Tukey multiple comparisons procedure was used to assess results. Overall, mean fracture strength ranged from 15.7 to 70.4 N·cm. Miniimplants with larger diameter exhibited higher peak torque values at fracture and higher yield strength, regardless of brand. In addition, significant differences across brands were observed when implants were stratified by diameter. In conclusion, larger miniimplant diameter is associated with increased fracture torque resistance. Additional information on peak torque values at fracture of different commercial brands of miniimplants may increase the success rate of this orthodontic anchorage modality.

O objetivo do presente estudo foi avaliar a resistência de fratura ao torque de miniimplantes ortodônticos. Foram utiliza das cinco marcas comerciais (SIN®, CONEXÃO®, NEODENT®, MORELLI® e FORESTADENT®). Para cada diâmetro, de cada marca comercial, foram testados 10 miniimplantes, totalizando 100 amostras. Os miniimplantes foram submetidos a um Ensaio Estático de Torção, conforme a norma técnica ASTM F543. Os resultados foram submetidos à Análise de Variância (ANOVA) complementado pelo teste de compa rações múltiplas de Tukey. Os valores médios de resistência de fratura ao torque variaram de 15,7 a 70,4 N·cm e miniimplantes de maior diâmetro apresentaram maiores valores de torque máximo de fratura e de limite de escoamento, independente da marca comercial. Além disso, foram obser vadas diferenças significativas entre as marcas comerciais quando agrupadas de acordo com o diâmetro. Concluise que miniimplantes de maior diâmetro apresentaram maiores valores de resistência de fratura ao torque. Informações sobre o torque máximo de fratura das diferentes marcas comerciais podem aumentar o índice de sucesso deste método de ancoragem ortodôntica.

Titanium alloy orthodontic mini-implants: scanning electron microscopic and metallographic analyses.

Anchorage control is one of the determining factors of successful orthodontic mechanics. In mini-implants, fractures due to placement and removal have been related to implant design and titanium alloy quality. This study assessed the topography and microstructure of five brands of mini-implants (Neodent, SIN, Morelli, Conexao, Foresta Dent). Scanning electron microscopic analyses of the head, transmucosal neck, threaded body, and tip were performed to assess implant design and manufacturing defects (n=3/group). Metallographic analysis of longitudinal sections (n=15) and cross-sections (n=15) was performed under conventional light microscopy according to international standards of "American Society for Testing and Materials". The results showed significant differences in miniimplant design. Surface irregularities in the threaded body and tip were observed. Microstructural analyses revealed an alpha/beta-phase grain structure, in compliance with the ETTC-2 ("Technical Committee of European Titanium Producers" -2nd edition). No structural defects were detected. We conclude that differences in mini-implant design and the presence of surface irregularities may influence the effectiveness of orthodontic anchorage.

Titanium alloy orthodontic mini-implants: scanning electron microscopic and metallographic analyses

Anchorage control is one of the determining factors of successful orthodontic mechanics. In mini-implants, fractures due to placement and removal have been related to implant design and titanium alloy quality. This study assessed the topography and microstructure of five brands of mini-implants (Neodent, SIN, Morelli, Conexao, Foresta Dent). Scanning electron microscopic analyses of the head, transmucosal neck, threaded body, and tip were performed to assess implant design and manufacturing defects (n=3/group). Metallographic analysis of longitudinal sections (n=15) and cross-sections (n=15) was performed under conventional light microscopy according to international standards of "American Society for Testing and Materials". The results showed significant differences in miniimplant design. Surface irregularities in the threaded body and tip were observed. Microstructural analyses revealed an alpha/beta-phase grain structure, in compliance with the ETTC-2 ("Technical Committee of European Titanium Producers" -2nd edition). No structural defects were detected. We conclude that differences in mini-implant design and the presence of surface irregularities may influence the effectiveness of orthodontic anchorage.

O controle da ancoragem e um dos fatores decisivos no sucesso da mecanica ortodontica. Fraturas devido ao estresse de insercao e remocao de mini-implantes sao associadas ao design das pecas e a qualidade da liga de titanio. O presente estudo analisou a topografia e a microestrutura de cinco marcas de mini-implantes (Neodent, SIN, Morelli, Conexao, Foresta Dent). Analise ao microscopio eletronico de varredura da cabeca e perfil transmucoso, porcao rosqueavel e ponta ativa foi realizada com o proposito de avaliar o design e defeitos de fabricacao (n=3/grupo). A analise metalografica baseou-se nas normas internacionais da "American Society for Testing and Materials" e revelou a microestrutura em cortes longitudinais (n=15) e transversais (n=15) por meio do microscopio optico. Os resultados demostraram que os mini-implantes apresentam diferencas significativas no design. Irregularidades superficiais na porcao rosqueavel e na ponta ativa foram tambem observadas. A analise da microestrutura revelou uma estrutura de graos fases alfa e beta distribuidas de acordo com os padroes definidos pelas normas ETTC-2 ("Technical Committee of European Titanium Producers" - 2a edicao). Alem disso, nao foram detectados defeitos na estrutura interna das ligas. Conclui-se que diferencas no design dos mini-implantes e a presenca de irregularidades superficiais podem influenciar na efetividade da ancoragem durante o tratamento ortodontico.

Natal primary molar: clinical and histological aspects.

The authors report a case of natal primary molar in a healthy 14-day-old child. The diagnosis of the case and the treatment plan are discussed, as well as histological analyses of the natal tooth. The tooth presented an immature appearance, with high mobility and insertion only in soft tissue, and therefore the clinical option adopted was dental extraction. Histological analyses revealed enamel hypoplasia and dentin showing a typical tubular pattern without alterations. The soft tissue had young and richly vascularized pulp with areas of chronic inflammatory infiltration.