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OBJECTIVES: This study aimed to compare the fracture resistance of a bulk-fill and a conventional composite and a combination of both for coronal restoration of severely damaged primary anterior teeth. MATERIALS AND METHODS: In this in vitro experimental study, 45 primary anterior teeth were randomly divided into three groups. After root canal preparation, the canals were filled with Metapex paste such that after the application of 1 mm of light-cure liner, 3 mm of the coronal third of the canal remained empty for composite post fabrication. Filtek Z250 conventional composite was used in group 1, Sonic-Fill bulk-fill composite was used in group 2 and Sonic-Fill with one layer of Filtek Z250 as the veneering were used in group 3. Adper Single Bond 2 was used in all groups. The teeth were thermocycled, and fracture resistance was measured by a universal testing machine. The mode of fracture was categorized as repairable or irreparable. Data were analyzed using one-way ANOVA. RESULTS: The mean fracture resistance was 307.00±74.72, 323.31±84.28 and 333.30±63.96 N in groups 1 to 3, respectively (P=0.55). The mean fracture strength was 14.53±2.98, 15.08±2.82 and 15.26±3.02 MPa in groups 1 to 3, respectively (P=0.77). The frequency of repairable mode of failure was 80% for the conventional, 73.6% for the bulk-fill and 80% for the bulk-fill plus conventional group, with no significant difference (P>0.05). CONCLUSION: Bulk-fill composites can be used for coronal reconstruction of severely damaged primary anterior teeth similar to conventional composites to decrease the treatment time in pediatric patients.
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STATEMENT OF THE PROBLEM: There are some differences between clinical features of central giant cell granulomas (CGCGs) and peripheral giant cell granulomas (CGCGs) despite their same microscopic features. The possible role of angiogenesis in this issue is still a matter of debate. PURPOSE: The aim of the present study was to compare microvessel density (MVD) between CGCGs and PGCGs of the oral cavity using CD31 and CD34. MATERIALS AND METHOD: Immunohistochemical staining was performed on 18 PGCGs and 19 CGCGs using a monoclonal antibody against CD34 and CD31. MVD was assessed and compared between the lesions using t-test for statistical analysis. p< 0.05 was considered significant. RESULTS: The expression levels of both CD34 and CD31 were significantly higher in CGCGs compared to PGCGs (p< 0.002 and p< 0.001, respectively). Significant differences in MVD assessed by both markers were observed between males and females in PGCGs (p< 0.05), but not CGCGs (p< 0.2). CONCLUSION: The combined evaluation of old- and newly-formed vessels by pan-endothelial cell markers showed differences between CGCGs and PGCGs, supporting the possible vascular-proliferative nature of the former. Whether this difference has a part in their diverse biologic behaviors and the role which pre-existent vessels play in comparison to neo-formed vasculature, requires further investigation.
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OBJECTIVES: This study aimed to assess the bite force of 3-6-year-old children in primary dentition period after unilateral extraction of a primary first molar (D) and its correlation with the height, weight, gender, type of occlusion, and temporomandibular disorders (TMDs). MATERIALS AND METHODS: Twenty children between the ages of 3 and 6 years with a unilaterally extracted D comprised our case group, and 29 age-matched children with no extracted teeth comprised the control group. The maximum bite force at the site of posterior teeth was measured using a bite force measuring device with a 0.2-mm thickness and 3-cm diameter, attached to a strain-gage sensor. Each child bit the sensor with maximum force for 3 seconds, and this was repeated three times at 10-minute intervals. The mean value was calculated. Data were analyzed using SPSS 18 software program via generalized estimating equation (GEE). RESULTS: the bite force on the side of extraction was significantly lower than that on the contralateral side (P<0.05). Also, the bite force was significantly correlated with the height, gender, and age, but the correlations between the bite force and weight, type of occlusion and side of the jaw were not significant (P>0.05). CONCLUSIONS: Extraction of primary first molars decreases the bite force on the respective side of the jaw.
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BACKGROUND AND AIM: This study aimed to assess the awareness of parents about the presence of first permanent molar and its effect on the health of this tooth. MATERIALS AND METHODS: This cross-sectional research has been done on 250 elementary school students which were 6 to 8-year-old boys and their parents in Tehran city. Sampling was done randomly. The questionnaires were filled out by the parents, and then tooth condition was registered in a visit formfor each student separately. Next, the related children's decayed missing filled teeth (DMFT) was determined and recorded. The mean value was calculated. Data were analyzed using the statistical package for the social sciences (SPSS) via a generalized estimating equation. RESULTS: There was a significant relationship between parental awareness of being permanent of the first permanent molar and DMFT (p < 0.05). CONCLUSION: Socio-economical factors like parental education can have an effect on oral health condition.How to cite this article: Heydari A, Shahrabi M, Shafizadeh M, Anaraki EA, Aref M, Parental Knowledge and Awareness of the First Permanent Molar. Int J Clin Pediatr Dent, 2018;11(5):382-385.
