Showing 6 results for Permanent
J. Mahmodian , A. Kusari , E. Faghih-E-Nasiri ,
Volume 11, Issue 4 (8-1998)
Abstract
Anterior tooth crown fracture in children is something that each dentist will confront many times during his professional career.We studied the prevalence of anterior teeth crown fractures between 7-14 years old students in Tehran and some relevant factors like sex, age, the traumatized tooth, amount of overbite and overjet, upper lip coverage, jaw that had fractured tooth or teeth and place of fracture in fractured crown.1338 boys and 1184 girls were in this study. Tooth fracture was almost the same in boys and 1184 girls with the prevalence of 8%. Fracture was mostly in enamel and average year of fracture was 10 years.Increased overjet and overbite had direct relation and indirect relation with fracture, also enough lip coverage showed less fracture.
B. Seraj ,
Volume 14, Issue 4 (1-2002)
Abstract
Whenever the first permanent molar is extracted or its long- term prognosis is poor, before taking any steps, a full clinical and radiographic evaluation associated with patient's dental models investigation is necessary to determine the following cases:The quality and quantity of dentition, teeth missing, occlusion, buds position, orthodontic problems, the level of parents and patient cooperation for future long term orthodontic treatment and finally patient's oral hygiene. On the basis of this information, a decision is taken about the first permanent molar extraction with poor prognosis, either of balancing or compensatory type, especially when future orthodontic treatment is improbable. The aim of this article is to explain the principles of time and sequence of first permanent molar extraction.
F. Aghahosseini , M. Enshaei ,
Volume 14, Issue 4 (1-2002)
Abstract
Epidemiologic studies have shown that caris or "infective damage of hard tissues in teeth" are the most common type of infection in human. In Iran, a few studies have investigated this hygienic problem, but no practical results have been defined yet. In this research, the conditions of the first upper and lower permanent molars (it contains four minor variables), have investigated. For this reason, in a descriptive analytic study, which was of retrospective and cross- sectional type, one thousand files were chosen systematically. The data were analysed by SPSS packages. The mean values of DMFT for permanent first molars were 3.47±0.50 (MT-1.23, FT=0.86, DT-1.38). The number of extracted teeth in mandible was moer than maxilla and the number of untreated caries teeth in maxilla was more than mandible (PO.001). DMFT ratio of the first molars to total DMFT, was approximately 29%, which indicates that caries and that complications on the first molars, make the main part of the overall DMFT. Therefore, hygiene training, preventive methods and the improvement of ecomonical status seem necessary in dental services.
M. Ghandehary- Motlagh , P. Farajy ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement of Problem: Central crown fractures of deciduous and permanent teeth lead to unfavorable psychological effects on both children and their parents. Moreover, it can cause malocclusion. So,recognizing tooth fracture reasons plays an important role to prevent its side effects.
Aim: The aim of this study was to investigate the reasons' of permanent central crown fractures in (7-12)years old children.
Materials and Methods: Records of 218 children, with at least one central tooth fracture, referred to pediatric department of faculty of dentistry of Tehran University of Medical Sciences, from 1999 to 2000, were studied. All the related information about fracture such as: reason, location, time, type of occlusion, and type of fracture were recorded.
Results: It was found that falling down (45.4%) and having contact with external objects (21.6%) were the main reasons for permanent centrals fractures. The mean age of these children was 9.78±1.24 and 63.3% of them were boys. It should be noted that 41.3% of them had unsupported lip. The highest rate of fractures belonged to upper centrals. Based on Ellis classification, most fractures were of degree 3 (52.7%). There was no significant relationship between overbite and overjet with the degree of fracture (P<0.05).
Conclusion: Dental skeletal malocclusions such as CI II, Div I, central incisors protrusion and developmental defects of tooth structure should be considered as determinant factors in tooth crown fractures.
F. Shafiei , M. Mortazavi , M. Memarpoor ,
Volume 19, Issue 1 (4-2006)
Abstract
Background and Aim: Although the use of adhesive systems can be effective in decreasing microleakge, it is still a major problem in composite resin restorations. The aim of the present study was to evaluate the marginal sealing ability of resin composite restorations using four dentin bonding systems in both primary and permanent teeth.
Materials and Methods: In this experimental study, one hundred and sixty extracted human teeth (80 primary and 80 permanent) were selected. All of the samples received a class V cavity preparation on the buccal surfaces (The coronal half in enamel and the gingival half in cementum or dentin). Each group was then divided into four subgroups each containing 20 teeth. Four different dentin bonding systems (Scotchbond Multipurpose, Single Bond, Clearfil SE Bond and Prompt L-Pop) were used in each subgroup. Then the cavities were filled with composite resin (Z100 for SBMP and Clearfil AP-X for Clearfil SE Bond). Samples were thermocycled, immersed in 0.5% basic fuschin, cut faciolingually and evaluated for dye penetration using a binocular stereomicroscope. Kruskal-Wallis and Dunn tests were used for comparison of microleakage between groups with p<0.05 as the limit of significance.
Results: The results showed that: There was significant difference in microleakage among four adhesive systems in both incisal and gingival margins of permanent teeth and in incisal margin of primary teeth (P=0.000, P=0.002, P=0.000 respectively). There was no significant difference in microleakage of restorations with each of four systems between permanent and primary teeth in both incisal and gingival margins except for PLP, which showed a significant different microleakage in the cervical margins (P=0.009). PLP showed better cervical seal in primary teeth compared to permanent teeth. Clearfil SE Bond showed acceptable results at incisal and cervical margins in primary teeth in comparison to other bonding systems.
Conclusion: Based on the results of this study, CSEB, SB and SBMP systems showed acceptable clinical results in primary and permanent teeth. Only PLP showed weak results in reducing microleakage. CSEB can be used successfully in primary teeth because of simplicity and reducing leakage in primary dentin and enamel.
Haghgoo Roza , Haghgou Hamid Reza , Abbasi Farid , Tavakkoli Mohammad ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: The main cause of erosion is acid exposure . Side effects of erosion necessitate therapeutic agents’ uses. The aim of this study was to investigate the effects of nano- hydroxy apatite in tooth remineralization following exposure to soft beer.
Materials and Methods: This in vitro experimental study was conducted on 18 human impacted third molars that had been surgically extracted. The microhardness of specimens was measured. Then teeth were exposed to soft beer and their secondary microhardness was measured. The teeth were divided into 2 groups (water and nano-hydroxy apatite solution) and were placed on 9 orthodontics appliances and delivered to 9 volunteers. These volunteers placed the tooth on one side in water for 5 minutes and the tooth in opposite side in nano-hydroxyapatite solution. This application was repeated 6 times a day for 10 days. The microhardness of teeth was measured again. Data were analyzed using Paired T-test.
Results: The tooth enamel microhardness reduced after exposure to soft beer significantly (P=0.04). The microhardness of 9 teeth after being in water showed significant changes (P=0.012). The microhardness of 9 teeth significantly changed after exposure to nano -hydroxyapatite solution (P=0.001) .
Conclusion: Based on the results of this study, 10% solution of nano- hydroxy appatite could restore the erosive lesions .
