Résumé
Posterior composite resins have gained considerable importance over last few years. However, improper placement techniques continue to be a prime cause of failure of these restorations. This study was done to compare the microleakage at the tooth restoration interface extending below cementoenamel junction when posterior composite restorations were placed directly in the cavity or when placed over a glass ionomer cement liner, both chemically cured and light cured. The results have shown that light cured glass ionomer when used as a liner under a composite restoration used below gingival cementum/dentin margin has the best sealing capability.
Sujets)
Mordançage à l'acide , Analyse de variance , Méthacrylate bisphénol A-glycidyl/composition chimique , Agents colorants/diagnostic , Résines composites/composition chimique , Collage dentaire , Isolation de cavité dentaire , Préparation de cavité dentaire/méthodes , Cément dentaire/anatomopathologie , Émail dentaire/anatomopathologie , Percolation dentaire/classification , Restaurations dentaires permanentes , Dentine/anatomopathologie , Agents de collage dentinaire/composition chimique , Ciment ionomère au verre/composition chimique , Humains , Humidité , Lumière , Poly(acides méthacryliques)/composition chimique , Statistiques comme sujet , Propriétés de surface , Température , Thermodynamique , Col de la dent/anatomopathologieRésumé
This study was undertaken to assess the efficacy of three luting cements, namely, glass ionomer, zinc phosphate and zinc polycarboxylate in retainng the preformed stainless steel crowns in-vivo. Twenty subjects, with an indication for restoration of three primary molars with stainless steel crowns, were selected. Sixty teeth were taken up for the study, and twenty crowns were cemented with each of the three luting cements. After an eight month follow up the crowns were assessed for their presence/ absence or "rocking". Statistical analysis was done using Chi-square test. The results have shown no significant difference in retentivity of stainless steel crowns with the use of either of the three luting agents.
Sujets)
Cimentation/méthodes , Enfant , Enfant d'âge préscolaire , Couronnes , Rétention de prothèse dentaire , Échec de restauration dentaire , Ciment ionomère au verre , Humains , Molaire , Ciment carboxylate , Acier inoxydable , Dent de lait , Ciment phosphate zincRésumé
A Paediatric dentist may be the first person consulted for professional advice concerning children with speech problems. A positive significant relationship has been hypothesized by some authors between tongue-thrust swallowing and articulation disorders in children. This study was undertaken to find out whether any articulation disorders are associated with the habit of tongue-thrust swallowing, or is it the type of anterior bite that plays an important role in the normal or abnormal speech production in tongue-thrust swallowers. Forty subjects with tongue-thrust swallowing in the age group of 7-16 years were examined. Of these 20 had normal anterior bite while rest had anterior open bite. A word articulation test was used and word level articulation testing was done for initial, medial and final positions. The sounds tested were: Linguoalveolars, Labiodentals, Linguodentals, Linguopalatals, Bilabials and Linguovelars. The results of the study have indicated that the presence of articulation disorders is strongly associated with the anterior open bite present in tongue-thrust swallowers but a simple, direct relationship between the presence of defective consonant sounds and tongue-thrust swallowing has not been found.