S A Mohamed Ali1, P S Manoharan2, Kuldeep Singh Shekhawat3, Saikat Deb4, S Chidambaram5, Jagadish Konchada6, Nirupa Venugopal7, Harish Vadivel8. 1. Assistant Professor, Department of Prosthodontics, Indira Gandhi institute of Dental Sciences , Pondicherry, India . 2. Head and Professor, Department of Prosthodontics, Indira Gandhi institute of Dental Sciences , Pondicherry, India . 3. Assistant Professor, Department of Community Dentistry, Indira Gandhi Institute of Dental Sciences , Pondicherry, India . 4. Assistant Professor, Department of Prosthodontics, Mithila Minority Dental College and Hospital , Darbhanga, Bihar, India . 5. Head and Professor, Department of Orthodontics, Ultra Dental College Tamil Nadu, India . 6. Assistant Professor, Department of Prosthodontics, Sree Sai Dental College and Research Institue , Srikakulam, India . 7. Consultant Prosthodontist & Private Practioner, Chennai, India . 8. Assistant Professor, Department of Dentistry, Menakshi ammal Medical College , Chennai, India .
Abstract
AIMS AND OBJECTIVES: One of the factor which affects the strength of the tooth restored with core material is the property of the material. In clinical situation all such restored teeth are protected by crowns. This study evaluated the strength of different core materials on a compromised tooth structure after restoration with a crown. MATERIALS AND METHODS: Seventy extracted intact human premolars were collected and mounted within a mould using auto-polymerizing resin. The teeth were divided in-to four groups - A, B, C and D. Each group contained 20 teeth except group A with 10 teeth. All the teeth were prepared for full veneer cast crown. Except for the teeth in group: A) extensive class-I cavities were prepared in the teeth of all the groups and restored with; B) composite resin, 3M EPSE Filtek P60; C) Silver reinforced glass ionomer, SHOFU Hi Dense XP and; (D) Resin reinforced glass ionomer, GC Gold Label light cure GIC. All the teeth were restored with cast-metal alloy and exposed to 1.2 million cycles of cyclic loading in a chewing simulator. Subsequently, the teeth that survived were loaded till fracture in the universal testing machine. Fracture loads and type of fractures were recorded. RESULTS: All the specimens survived cyclic loading. The mean fracture strength of the silver reinforced glass ionomer was greater with and without crown (p<0.001). Statistical analysis for the mean fracture load of each specimen showed significant difference between the groups. CONCLUSION: Under the condition of this study, core materials when restored with artificial crown had a significant increase in fracture resistance.
AIMS AND OBJECTIVES: One of the factor which affects the strength of the tooth restored with core material is the property of the material. In clinical situation all such restored teeth are protected by crowns. This study evaluated the strength of different core materials on a compromised tooth structure after restoration with a crown. MATERIALS AND METHODS: Seventy extracted intact human premolars were collected and mounted within a mould using auto-polymerizing resin. The teeth were divided in-to four groups - A, B, C and D. Each group contained 20 teeth except group A with 10 teeth. All the teeth were prepared for full veneer cast crown. Except for the teeth in group: A) extensive class-I cavities were prepared in the teeth of all the groups and restored with; B) composite resin, 3M EPSE Filtek P60; C) Silver reinforced glass ionomer, SHOFU Hi Dense XP and; (D) Resin reinforced glass ionomer, GC Gold Label light cure GIC. All the teeth were restored with cast-metal alloy and exposed to 1.2 million cycles of cyclic loading in a chewing simulator. Subsequently, the teeth that survived were loaded till fracture in the universal testing machine. Fracture loads and type of fractures were recorded. RESULTS: All the specimens survived cyclic loading. The mean fracture strength of the silver reinforced glass ionomer was greater with and without crown (p<0.001). Statistical analysis for the mean fracture load of each specimen showed significant difference between the groups. CONCLUSION: Under the condition of this study, core materials when restored with artificial crown had a significant increase in fracture resistance.