RESUMO
AIM: The aim of this study was to evaluate the influence of different regions of dentin within the post space on the retention of fiber posts. MATERIALS AND METHODS: Ten human incisors with straight roots were selected for this study. Endodontic treatment of the specimens was done. The post spaces were created immediately after obturation and the posts were luted with dual-cure resin cement. Approximately 2.5-mm-thick sections were made from the coronal, middle, and apical thirds of the post space and thus we had three groups: Group I: Cervical, Group II: Middle, Group III: Apical. The specimens were tested on a universal testing machine. Statistical analysis was done using the unpaired Student's t-test and one-way ANOVA test. RESULT: The best push-out strength was obtained with the apical sections (14.69 ± 0.298 MPa), followed by the middle (10.66 ± 0.34 MPa) and cervical sections (9.73 ± 0.42 MPa). CONCLUSION: highest pust out strengths were obtained in apical sections followed by middle and coronal.
Assuntos
Retenção em Prótese Dentária , Cavidade Pulpar/ultraestrutura , Dentina/ultraestrutura , Técnica para Retentor Intrarradicular/instrumentação , Resinas Compostas/química , Colagem Dentária/métodos , Análise do Estresse Dentário/instrumentação , Resinas Epóxi/uso terapêutico , Vidro/química , Cimentos de Ionômeros de Vidro/química , Guta-Percha/uso terapêutico , Humanos , Incisivo/ultraestrutura , Teste de Materiais , Materiais Restauradores do Canal Radicular/uso terapêutico , Obturação do Canal Radicular/métodos , Preparo de Canal Radicular/métodos , Autocura de Resinas Dentárias , Estresse Mecânico , Ápice Dentário/ultraestrutura , Raiz Dentária/ultraestruturaRESUMO
The second premolars have the highest incidence of congenital absence, after the third molars. The problem resides not in the prevalence of congenitally missing premolars but in the selection of a treatment plan that will yield the best results over the long term. The present study reports a case of a 14 year old female patient with bilaterally congenitally missing second mandibular premolars with associated crowding of teeth. The case has been managed using a multi-speciality approach, in which both deciduous mandibular second molars were sectioned and the distal half retained. The retained half was prepared to receive a full coverage restoration which was contoured as a premolar. The space created was then utilized to correct the crowding by fixed orthodontics. A two year follow up shows retained distal half of the deciduous mandibular second molar with correction of crowding and space closure.