ABSTRACT
"Power Bleaching" which is a new an in-office whitening technique with a combination of a whitening agent [peroxide] and an auxiliary [plasma-Arch light], has been claimed to be an effective and fast method in tooth bleaching. What is more important in using this method is the maintenance of the pulp health after tooth whitening. The aim of this study was to evaluate the human pulpal response after bleaching with H2o2 38% and plasma-Arc light. Eighty seven sound first premolars from 27 patients were selected and divided into 3 groups of 29, based on the time intervals of histologic evaluation. In each group 9 teeth were considered as a control. Vitality tests were done before bleaching [base line] and in four intervals of 2, 7, 30 and 60 days, but histologic evaluation was performed in three intervals 2, 7 and 60 days. Immediately after extraction, apical one third of the roots were sectioned off and each specimen was placed in 10% buffered formalin solution for pulpal fixation. EDTA was used for decalcification and sections were prepared from each specimen and stained with H and E and subsequently assessed microscopically for the following criteria: Irregularities in the odontoblastic layer, the presence of inflammatory cell, vasodilatation and pulpal fibrosis. Data was analyzed using Friedman test and Wilcoxon test [alpha= 0.05]. There were significant differences between the 2 and 60 days groups and between 7 and 60 days groups with respect to inflammatory responses and vasodilatation [p<0.05]. Comparison of the control and experimental groups of the 2 and 7 days revealed statistically significant differences in inflammation and vasodilatation [p<0.05]. No patient had experienced sensitivity, after different bleaching periods. Bleaching of teeth with H2o2 38% and plasma-Arc light might cause slight to moderate pulp reactions after 2 and 7 days confined to the coronal pulp. However, the observed histological changes did not affect the overall health of the pulp tissue permanently
ABSTRACT
A paramount objective of modern orthodontic therapy is the improvement of facial esthetics. Orthodontic treatment can cause an attractive smile through change in position of the anterior teeth. Thus the purpose of this study was to determine the standards of the beautiful smiles and also the effects of non extraction orthodontic treatment on smile esthetics. Sixty three women, 30 with non extraction orthodontically treated occlusions and 33 with normal occlusion were selected. Five standardized black and white close- up image of their posed smiles were taken and then the most natural photograph of each case were selected. At next selected photographs were evaluated by a panel of five men and five women of varied vocations. They were told to rate each photograph as to the attractiveness of the individual smile with visual analogue scale. This study showed 27.3% of normal occlusion females with out history of orthodontic treatment had very good, 57.6% had good and 15.1% had fair smiles. But in none extraction orthodontically treated group 10% had very good, 76.7% had good and 13.3% had fair smiles. As the result of the panel members evaluations, orthodontically treated subjects and subjects with normal occlusion had similar smile scores. Furthermore smile line ratio, buccal corridor ratio and symmetry ratio were not significantly different between two groups. On the other hand, there were no significant difference in smile morphometric indices between fair, good and very good smiles. This study demonstrates that the smile line, buccal corridor and symmetry of smile do not influence smile esthetics and also orthodontically treated subjects and subjects with normal occlusion had similar smile esthetics
ABSTRACT
Considering the influence of functional matrix on the morphogenesis of jaws and teeth, it is essential to accept that functional forces will cause a change in tooth position and bone formation. The purpose of this research was to study the dental and skeletal effects of maxillary protraction following the use of tongue guard myofunctional appliance in children with class Ill malocclusion with maxillary deficiency. Pretreatment and posttreatment lateral cephalograms from 23 patients [11 male and 12 female] with mean age of 8.77 years treated by tongue guard myofunctional appliance in orthodontics clinic of Mashhad Dental School were traced and analyzed. Average treatment time was 6 months. Differences between before treatment [BT] and after treatment [AT] values were analyzed using SPSS statistical software [paired T. test]. The results were as follow: 1. A highly significant anterior movement of maxilla occurred with increases in SNA [with mean=1 degree] and ANB [with mean=0.96 degree] angles and anterior movement of A point in Wits analysis [P=0.001]. 2. Maxilla/Mandible ratio [according to A.M. Schwarz] increased [P=0.001]. 3. The maxillary incisors moved in anterior direction. 4. The mandibular incisors moved posteriorly. In other words, IMPA decreased [P<0.05]. 5. Profile convexity increased and Soft tissue profile and upper lip area improved. The results of this study indicates that use of tongue guard myofunctional appliance is appropriate for patients initially presenting with anteroposterior and vertical maxillary deficiency