Frontiers in Dentistry
Volume:5 Issue: 2, Spring 2008

The purpose of this study was to investigate the histological response to deliberate perforation repaired using amalgam or MTA either immediately or with delay on cats'' molars. Twenty-eight molar teeth from four cats were used in this experimental randomized study. After preparing the access cavity, the floor of pulp chambers were deliberately perforated with a round bur No. 5. The teeth were randomly divided into four groups of seven. In groups one and two the perforation was immediately sealed with amalgam and MTA, respectively. In groups three and four the perforations were left exposed to saliva for six weeks and then sealed with amalgam or MTA. The animals were sacrificed four months later and the specimens processed. The samples were blindly examined for inflammatory reaction and healing process under light microscope. The data were analyzed with Mann-Whitney U and Fisher exact tests. The type of the materials used has no significant effect on the severity of inflammation; while, immediate or delayed repair of furcal perforation has, and immediate application of, MTA produced less inflammation than that of amalgam (P=0.03). No differences were found in vasodilatation, abscess formation or healing process between the immediate and the delayed repair groups (P=0.13). MTA is a more suitable material than amalgam for perforation repair, particularly when used immediately after perforation.

The main objective of this study was to investigate relationship between reported dietary habits and dental caries in five and six-year-old children referred for dental extractions Two hundred children were examined using standard caries diagnostic criteria. The numbers of decayed, missing and filled deciduous teeth were recorded. A food frequency table was completed by the parents of each child and analyzed through weighting the cariogenic potential by the frequency of consumption, and summing the two scores. The mean number of decayed, missing and filled teeth (dmft) was 7.1 (SD=3.29). There was no statistically significant correlation between the reported dietary intake and the caries rate in the study population P=0.07. Use of bottles with sugared drinks during infancy was associated with increased caries levels (P<0.01). Poor infant feeding practices promote caries in childhood. A method of diet assessment which would evaluate diet-related health education is required.

The aim of this study was to determine the prevalence of needlestick injury (NSI) and the factors associated with it among medical and dental students in Kerman province during the 2006 year. A cross-sectional study was conducted among 269 medical and dental students to evaluate NSIs and practices regarding the protective strategies. These students were asked to complete a self-administered questionnaire. The data were analyzed by t-test and chi-square test. The questionnaires were completed by 245 students, of which 74.3% (182) had NSIs. The highest incidence among medical students was found to be in surgery ward and the emergency room, followed by Orthopedics and Internal wards, whilst the highest incidence among the dental students was seen in Endodontics, Surgery, and Periodontics Departments. Medical and dental students were found at a high risk of NSIs and blood-borne infections during their clinical activities. Therefore, some preventive measures seem necessary to be taken into consideration

Loss of tooth structure due to dental caries and cavity preparation can reduce fracture resistance, especially in endodontically treated teeth. The aim of the present study was to evaluate fracture resistance of pulpotomized primary molar teeth restored with extensive multisurface amalgam restorations. Eighty extracted carious human primary molar teeth were selected forpresent study. Teeth were divided in to eight groups of ten. Mesio- or disto-occlusal and Mesio-occluso-distal cavities with different cavity wall thickness (1.5 or 2.5 mm) were prepared in both first and second primary molar teeth. After restoring teeth with amalgam, all specimens were stored in distilled water at 37°C for 7 days. Then samples were thermocycled for 1000 cycles from 5°C to 55°C. The specimens then were subjected to a compressive load in a universal testing machine at a crosshead speed of 0.5 mm min-1. ANOVA and t-test were used for statistical analysis. Mean fracture resistance of first and second molar teeth were 975.5 N (SD=368.8) and 1049.2 N (SD=540.1) respectively. In the first molar group, fracture resistance of 2-surface cavities was significantly more than 3-surface cavities (P<0.001), however this difference was not statistically significant in the second molar group. In both first and second molar group, fracture resistance in cavities with 2.5 mm wall thickness, was significantly more than the group with 1.5 mm wall thickness. The mean fracture resistance in pulpotomized primary molar restored with amalgam restorations was higher than reported maximum bite force in primary teeth even in extensive multi-surface restorations. Therefore, the teeth with large proximal carious lesions in schoolchildren could be restored with amalgam.

An association between poor oral health and chronic lung disease has recently been reported. The purpose of this study was to explore this potential association between asthma and periodontal disease. This is a descriptive case controlled study. The samples were selected from patients referred to respiratory disease clinic in a hospital in Tehran, Iran. The study population comprised of one hundred individuals: fifty asthmatics and fifty asthmatic controls evaluated for Plaque index (PI), Gingival index (GI), Papillary Bleeding index (PBI), Periodontal Disease index (PDI) and Calculus index (CI). The data were analyzed by SPSS software. There were significant differences between asthmatics and non-asthmatic samples in PI, GI, BOP, and PDI (P<0.01). However, there was no such differences in CI between the two groups (P=0.084). The results of the present study support recent published reports advocating a relationship between respiratory disease and periodontal health status.

To study the accuracy of spiral tomography in the determination of implant angulation. Eighteen gutta-percha filled points on dry mandibles were selected for implant placement. A translucent acrylic template was fabricated for each mandible. After preparing tomographic images (2 mm slice thickness, Cranex Tome), the ideal axis of the implant was traced. The angle between the ideal axis and the tangent line on the alveolar crest in the buccal side was measured and transferred to aluminum sleeves by a protractor. After implant placement, tomographic images were taken again and angles of the actual implants were estimated. In addition, the distances from the tip of the actual and the supposed implants to the buccal cortex were measured. The data were analyzed by paired sample t test with 95% confidence. Less than two-degree difference between angles of the supposed and the actual implants was found in 44.4% of the cases, whilst 33.3% revealed more than five-degree difference. There was a significant statistical difference between the angle of the actual and the supposed implants. There was also a significant statistical difference between the linear distances from the tip of the actual and the supposed implants to buccal cortex (P=0.015) Spiral tomography in combination with template may provide acceptable results concerning implant angulation and prediction of cortical perforation risk.

Pyknodysostosis is a rare bone disease that has autosomal dominant trait. It is characterized by short stature, diffuse osteosclerosis, acro-osteolysis, finger, and nail abnormalities. Other features include open fontanelles and sutures, relative proptosis and obtuse mandibular gonial angle with relative mandibular prognathism. Intraoral features such as dental abnormalities also have been reported. In this report, a case of pyknodysostosis in a 9-year-old boy is presented. Most of the observed features were comparable to the other case reports but some findings such as repeated chest infection, sleep apnea, kyphosis, scoliosis, root shortness, pulp narrowing, supernumerary and hypodontia could not be observed in this case.Instead, in this patient features such as anterior open bite and decreased anterior tooth display, not reported in other cases, was evident.