ABSTRACT
Objective: Resistance to fracture is a critical issue when it comes to tooth restoration. The purpose of this study was to evaluate the fracture resistance of pulpotomized primary molars restored with glass ionomer [GI], amalgam and composite resin with and without cusp reduction
Methods: In this in-vitro experimental study, 60 extracted primary teeth were randomly divided into 6 groups of 10. In all groups except for the control group, conventional pulpotomy and MOD cavity preparation were performed in a way that the cavity isthmus width was equal to two-third of the inter cuspal distance. Group 1 teeth were restored with Kerr amalgam and underwent 1.5 mm cusp reduction, group 2 received Z250 composite resin onlay with 1.5 mm cuspal coverage, group 3 was restored similar to group 2 but without cusp reduction, group 4 was restored as group 3 but with Quixfil composite and group 5 was restored just like the former two groups but with GI. The restored teeth underwent thermo cycling and were subjected to Universal Testing Machine with a crosshead speed of 0.5 mm/min
The recorded fracture resistance of specimens was compared. One- way ANOV A was used for statistical analysis
Results: The mean fracture resistance was 2001.929 in the control group, 904.749 in the amalgam group, 1101.736 in Z250 composite with no cusp reduction group, 1036.185 in the Quixfil composite with no cusp reduction, 945.096 in the Z250 composite with cusp reduction and 850.313 in the GI group. The difference between the control group and other understudy groups was statistically significant [P<0.0001] but other differences were not statistically meaningful
Conclusion: Although in none of the groups the fracture strength was equal to that of intact primary teeth, the obtained values were within the normal range of masticatory forces
ABSTRACT
Objective: Various factors affect dental caries and impact the patterns of dental care. A few studies have been conducted to identify these factors from the perspectives of students. This study aimed to explore factors influencing dental caries from students' perspectives
Methods: A qualitative design using content analysis approach was conducted to collect the perspectives of 18 Iranian students who were studying in 8 guidance schools. They were chosen through purposive sampling. Semi- structured private interviews and focus groups were held for data gathering. The tape-recorded interviews were transcribed verbatim and analyzed using an inductive content analysis approach. In order to support the validity and rigor of the data, different trustworthiness criteria such as acceptability, confirm ability and transferability were considered
Results: During data analysis, four main categories were developed: [difficult conditions of care], [disability in caring], [uncontrollability of dental caries] and [intangible sense of the factors causing dental caries]. The participants more emphasized their own experiences about having insufficient dental-oral care, not paying attention to oral health, dental fear and the lack of both knowledge and competency regarding this issue
Conclusion: The findings of this study revealed factors influencing dental caries from students' perspectives and emphasized the roles of individual, parent, dentist and community in this respect
The findings of this study can be considered to be a valuable basis to design oral health interventions. However, more studies are required to improve our understanding of dental fear and denote barriers and social beliefs pertinent to oral health in different groups of students