ABSTRACT
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.
Subject(s)
Acid Etching, Dental , Analysis of Variance , Bisphenol A-Glycidyl Methacrylate/chemistry , Coloring Agents/diagnosis , Composite Resins/chemistry , Dental Bonding , Dental Cavity Lining , Dental Cavity Preparation/methods , Dental Cementum/pathology , Dental Enamel/pathology , Dental Leakage/classification , Dental Restoration, Permanent , Dentin/pathology , Dentin-Bonding Agents/chemistry , Glass Ionomer Cements/chemistry , Humans , Humidity , Light , Polymethacrylic Acids/chemistry , Statistics as Topic , Surface Properties , Temperature , Thermodynamics , Tooth Cervix/pathologyABSTRACT
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.
Subject(s)
Cementation/methods , Child , Child, Preschool , Crowns , Dental Prosthesis Retention , Dental Restoration Failure , Glass Ionomer Cements , Humans , Molar , Polycarboxylate Cement , Stainless Steel , Tooth, Deciduous , Zinc Phosphate CementABSTRACT
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.