The Effect of Cavity Design on Fracture Resistance and Failure Pattern in Monolithic Zirconia Partial Coverage Restorations - An In vitro Study
| Autor: | Mandava Ramesh Babu, G Divya, Tejavath Sai Krishna, Gudugunta Leneena, Madhavareddy Sri Harsha, Mynampati Praffulla |
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| Rok vydání: | 2017 |
| Předmět: |
0206 medical engineering
Clinical Biochemistry lcsh:Medicine Dentistry 02 engineering and technology Crosshead zirconia cad 03 medical and health sciences 0302 clinical medicine Flexural strength Stereo microscope Medicine complete onlay Universal testing machine Inlay business.industry mod inlay lcsh:R Monolithic zirconia 030206 dentistry General Medicine 020601 biomedical engineering Dentistry Section partial onlay Posterior teeth Fracture (geology) business |
| Zdroj: | Journal of Clinical and Diagnostic Research, Vol 11, Iss 5, Pp ZC45-ZC48 (2017) |
| ISSN: | 2249-782X |
| DOI: | 10.7860/jcdr/2017/25305.9856 |
| Popis: | Introduction Cavity preparations of posterior teeth have been frequently associated with decreased fracture strength of the teeth. Choosing the correct indirect restoration and the cavity design when restoring the posterior teeth i.e., premolars was difficult as it involves aesthetic, biomechanical and anatomical considerations. Aim To evaluate the fracture resistance and failure pattern of three different cavity designs restored with monolithic zirconia. Materials and methods Human maxillary premolars atraumatically extracted for orthodontic reasons were chosen. A total of 40 teeth were selected and divided into four groups (n=10). Group I-Sound teeth (control with no preparation). Group II-MOD Inlay, Group III-Partial Onlay, Group IV-Complete Onlay. Restorations were fabricated with monolithic partially sintered zirconia CAD (SAGEMAX- NexxZr). All the 30 samples were cemented using Multilink Automix (Ivoclar) and subjected to fracture resistance testing using Universal Testing Machine (UTM) (Instron) with a steel ball of 3.5 mm diameter at crosshead speed of 0.5 mm/minute. Stereomicroscope was used to evaluate the modes of failure of the fractured specimen. Fracture resistance was tested using parametric one way ANOVA test, unpaired t-test and Tukey test. Fracture patterns were assessed using non-parametric Chi-square test. Results Group IV (Complete Onlay) presented highest fracture resistance and showed statistical significant difference. Group II (MOD Inlay) and Group III (Partial Onlay) showed significantly lower values than the Group I (Sound teeth). However, Groups I, II and III presented no significant difference from each other. Coming to the modes of failure, Group II (MOD Inlay) and Group III (Partial Onlay) presented mixed type of failures; Group IV (Complete Onlay) demonstrated 70% Type I failures. Conclusion Of the three cavity designs evaluated, Complete Onlay had shown a significant increase in the fracture resistance than the Sound teeth. |
| Databáze: | OpenAIRE |
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