ABSTRACT
BACKGROUND: Determination of maturation and evaluation of growth potential is extremely important in clinical orthodontics. The purpose of this study was to evaluate the diagnostic performance of the mandibular second molar calcification stages for identification of growth phases. MATERIAL AND METHODS: In this cross-sectional descriptive study, samples were derived from panoramic radiographs and lateral cephalograms of 125 subjects (61 males and 64 females) with age ranging from 8 to 17 years and estimates of dental maturity (Demirjian Index [DI]) and skeletal maturity (Cervical vertebral maturation indicators CVMI]) were made. Correlations between DI and CVMI were shown by Spearman's correlation. The diagnostic performance of the DI for the identification of the growth phase were evaluated using positive likelihood ratios (LHRs), with a threshold of ≥10 for satisfactory performance. RESULTS: Correlations between second molar calcification and growth phase were 0.819 for females and 0.805 for males (P-value< 0.0001). LHR ≥10 was only observed for the identification of the post-pubertal growth phase for the H stage of the second molar. CONCLUSIONS: In spite of the high correlation coefficients between mandibular second molar calcification stages and skeletal maturity, these stages are reliable only for the identification of the post pubertal growth phase. Key words:Skeletal maturation, demirjian Index, mandibular second molar.
ABSTRACT
INTRODUCTION: Multiple methods for evaluating microleakage have been introduced over the years, but there has been no agreement as to which technique will give more accurate results. The aim of this study was to compare the accuracy and results of fluid filtration and marginal adaptation methods for mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement apical plugs. METHODS AND MATERIALS: A total of 250 single-rooted human teeth were collected. The teeth were decoronated, the root canals were prepared and open apex condition was stimulated by passing #1 to 4 Peeso Reamer drills from apical foramen. Five teeth were selected as the positive and negative controls and the rest of the samples were randomly allocated to two groups of MTA and CEM cement plugs. In each group, apical plug was placed into the canal. After the apical plugs were completely set, microleakage and marginal adaptation of the samples were evaluated using fluid filtration method and scanning electron microscopy (SEM), respectively. The obtained results were analyzed by independent-samples t test. RESULTS: Gap between plug and dentin walls and air bubbles displacement was higher in MTA group compared to the CEM cement group, though this difference between MTA group and CEM cement group was not statistically significant. Conclusion: According to the obtained results, it seems that there is a direct relationship between the two methods of microleakage assessment.
ABSTRACT
INTRODUCTION: The aim of this study was to compare the marginal adaptation of mineral trioxide aggregate (MTA) and calcium-enriched mixture(CEM) cement apical plugs in open apex teeth in dry, blood- and saliva-contaminated canals. METHODS AND MATERIALS: A total of 120 human extracted single-rooted teeth were used. The teeth were decoronated and canals were cleaned and shaped up to #80 K-Files. After simulating open apex condition, samples were randomly divided into two groups (Group 1: MTA plug and group 2 CEM cement plug) and each group was then further divided into 3 subgroups (dry canal, blood- and saliva-contaminated canals). MTA and CEM cement apical plugs were placed into the canal. After full setting of apical plug, immediate marginal adaptation of the samples was assessed by electronic microscope. The data were analyzed using the two-way analysis of variance. RESULTS: There was no statistically difference between the average marginal gap in MTA and CEM cement groups in three different conditions. The average gap in dry canal was significantly lower than canal contaminated with blood and saliva. CONCLUSION: It seems that marginal adaptations of MTA and CEM apical plug was not significantly different in various conditions and the two materials can be used successfully in this method.
ABSTRACT
INTRODUCTION: Microleakage is of the causes of endodontic treatment failure. The aim of this in vitro study, was to compare the microleakage of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement apical plugs in three environments. METHODS AND MATERIALS: A total of 130 human extracted single rooted teeth were collected. After decoronation, preparation of the root canal space and simulation of open apices, 5 teeth were selected as positive and negative control groups and the rest of the samples were randomly divided into two groups (MTA plug and CEM cement plug) and each group was divided into 3 subgroups (dry, contaminated with saliva and contaminated with blood). In each group apical plug was placed into the canal. After full setting of the apical plug, microleakage of the samples were evaluated using fluid filtration method and the data were analyzed using two-way analysis of variance. RESULTS: In dry and saliva contaminated environments, the leakage of MTA samples were 40.906±2.081 and 39.608±2.081, respectively which was significantly more than that of CEM cement samples (26.977±2.081 and 27.000±2.081, respectively). However, in blood-contaminated environments, the amount of leakage in MTA group (21.640±2.081) was significantly lower than CEM cement group (44.358±2.081). CONCLUSION: According to the results of this study, in dry and saliva-contaminated conditions CEM cement provides significantly better seal in comparison to MTA.
