ABSTRACT
In regard to the prevalence of orthodontic treatments, the importance of relapse and complications followed by relapse are overlooked. This is further impacted by information gaps in Iranian Dental Journals and deficiencies in previous studies. In this study we have assessed the outcome of orthodontic treatment, relapse and related factors in patients in the Private orthodontic clinic in Tehran in 2009.This study was performed using a cross sectional technique. The samples consisted of all patients with various kinds of malocclusions and the presence of pretreatment, post treatment dental casts with at least 4 years post treatment. In these patients, we also prepared post retention dental casts. The indexes, including irregularity index, arch length, inter canine width, inter premolar width, and inter molar width in both upper and lower jaws were evaluated. The change in each index out of normal range indicated relapse. The role of related factors such as sex, patient's age at the beginning of the treatment, type of treatment, duration of the treatment, the length of retention, the type of malocclusion, and family history were analyzed using Chi Square test. This study was performed on 52 cases [26%] out of 200 cases which had complete records and positive response to recall. During the study period at least 500 patients were treated. The result of relapse was 61.5% without considering the irregularity index [42.3%]. The most important relapse index was maxillary irregularity index [37%], followed by the mandibular irregularity index [17%] and, the least significant index was mandibular arch length [2%]. Relapse was increased in patients with less than 24 months of treatment. [P<0.0001] Relapse was high regardless of irregularity index. Considering its complications, we suggest further studies to elucidate its etiology. This should be followed by preventive measures to decrease the rate of relapse
ABSTRACT
Posts are used as retention mechanism in repairing fractured or missing crowns of teeth. Nowadays composite fiber postes have eliminated most disadvantages of prefabricated metal and casting posts. the purpose of this study is to compare the amount of fracture resistance in three fiber posts [carbon fiber, quartz fiber, glass fiber] while shearing force [perpendicular to long axis] is applied. This invitro, experimental study was performed on 30 maxillary lncisors with the same size without fracture, dentin caries or any root problems they were in three groups randomly. [Carbon fiber, quartz fiber, glass fiber] After root canal treatment and post space preparation with specified drill, samples were carried under universal test machine [prinston] to evaluate the amount of fracture resistance Data was analyzed with Kruskall-wallis Test under spss13. There was significant difference in fracture resistance in all three groups. [P=0.001]. Also, the carbon fiber posts had the maximum and the glass fiber posts had the minimum amount of fracture resistance. since the carbon fiber posts have the maximum fracture resistance in comparison with other groups, their application in anterior teeth is preferred
ABSTRACT
One of the challenges of restoring endodontically treated teeth with fiber reinforced composite [FRC] posts is their debonding from root canal dentin. Different factors such as cement type, effect the post retention. According to the controversies in this regard, this study aimed to evaluate the effect of three luting cements on retention of FRC posts in the root canal. In this in-vitro study 30 selected root canal treated premolar teeth were randomly allocated to three experimental groups. After post space preparation, RTD fiber posts, with 10mm length and 2 mm diameter, were cemented in the canal with one of the following luting agents: zinc phosphate [Harvard], Glass-Ionomer [GC] and resin cement Maxcem [Kerr]. They were then fixed and force was applied using Instron 5500 machine. The Data was subjected to ANOVA for statistical analysis. The observed retention in studied groups was as follows: resin cement 127 +/- 18.5 [MPa], zinc phosphate 102 +/- 29.7 [MPa] and glass-ionomer 51 +/- 14.8 [MPa]. In order to increase the retention of FRC posts, cementation with resin cements is recommended
ABSTRACT
This study investigated whether breast arterial calcification [BAC] has an association with coronary artery diseases [CAD] in young premenopausal women and evaluated the association of BAC with carotid intima-media thickness and standard CAD risk factors. Among 84 premenopausal women aged < 55 years who were referred for coronary angiography, 34 [40.5%] had abnormal angiographic findings and 6 [7.1%] showed BAC in their mammograms. The body mass index of patients with BAC was significantly higher than those without BAC. BAC had no significant association with angiography-confirmed CAD