Daneshvar Medicine: Basic and Clinical Research Journal
Year:2003 | Volume:10 | Issue:44 (Special Editon on Dentistry Articles)|Papers Count:11

One of the problems concerning restorative dental materials is microleakage that leads to unfavorable consequences in dental restorations. In order to evaluate the microleakage in different materials' laboratory studies are needed. Usually human specimens are used in laboratory, but since providing the human specimen are very difficult and time consuming and also there is the risk of AIDS and HEPATITIS in this case, it is better to substitute human specimen. Bovine teeth have been used extensively in many studies. In this study we compared, the micro leakage between human and bovine teeth. In this study 10 human anterior permanent teeth and 10 bovine anterior permanent teeth were selected and class V cavities on buccal and lingual surfaces were prepared. The cavities were filled with composite and the specimen was thermocyled for 500 times. After storing the specimens in fuschin for 24 hours and sectioning them from the middle, they were scanned under stereomicrosope. The results showed that the amount of micro leakage in enamal was Zero but in dentin higher than that of enamal in both of the specimens. Also the gingival margins on the buccal surface of the bovine teeth had same amount of micro leakage in the same sw1ace in human teeth. But, the gingival margin on the lingual surface in bovine teeth had less microleakage compared to the some surface in human teeth. In the base of this study permanent anterior bovine teeth could be an acceptable substitute for human teeth in miroleakage studies. Of course more ex1ensiveinvestigations are needed to complete these studies.    

Recurrent aphthous ulcers are one of the most common disease of oral mucosa, that present with solitary multiple, painful ulcers on non keratinized mucosa. Persica is a contain salvadora persica, Achillea millefolium and mentha spicata and has antiviral, antifungal and anti-inflammatory effects. The object of this study was to determine the effect of persica on Aphthous ulcers. In this study, patients are divided in two groups; based on using of persica (40) and placebo (20). Screening sheet includes Age, sex, History of trauma, familial History the number of lesions frequency, duration, healing time and anxiety. It was' requested that patients referred as soon as possible, after healing. Patients were evaluated based on the changes in pain and time of healing, after using of the dl1lg or placebo. Based on data there was significant differences between two groups. According to this study, persica mouth rinses can be used as a treatment the recurrent aphthous stomatitis.    

The main purpose of this study was the comparison of' cholorhexidine and persica mouth rinses in control and prevention 0 oral complications after chemotherapy. 60 patients with acute leukemia were selected that were hospitalized in oncology department. A randomized double blind clinical trial was performed. The patients were divided in two groups based on using one of the two mouth rinses (1) Cholorhexidine (CW) - and (2) Persica (p). The results showed that: In (CH) group) the plaque index had decreased significantly (P<0.003). Candidous infection was detercted in 50% of patients in (p) group after two week~ (P<0.0007) and 53.3% of the same patients after three weeks, but in (CH) group there was no significant difference in duration of using mouth rinse and in (CH) group, pigmentation of teeth was detected in 43.3% of patients after two weeks (P<0.0005). But in (p) group there was no significant differences in duration of using mouth rinse and finding new cases of pigmentation of' teeth. Gingival index increased in (p) group after four weeks (30%) but in (CH) group this index was lower (16.6%).      

Edentulousness is a good indication of evaluating oro dental health status in a population. The aim of this cross - sectional study was to evaluate this index in people above 35 years of old in four cities of Iran (torbat - e heidarieh Yazd, Hamadan and Kazerron. The study was carried out by means of a questionnaire as well as clinical examination with random sampling out to 2391 participants. The percentages of edentuluseness were 52.04% in Hamadan, 39.3% in Kazerron, 32.8 in Torbateheidarieh, and 40.7% in Yazd. Results of this study showed that edeuntulousnes had significant relation with the following Factors: Age, education, oral health status. There was no significant relationship between gender and edentulousness.    

Linear tomography is one of the imaging modalities used for patient assessment prior to dental implant placement. This research evaluates the accuracy and validity of linear tomography in the imaging of human mandible. Eight edentulous mandibles were prepared. They were sectioned sagittaly in the midline and eight hemisectioned mandibles were selected. Linear tomography was applied for two locations in each mandible, one in 2nd premolar and the other in 2nd molar area. These locations were sectioned in coronal plane using a thin saw and the following parameters were measured: A) Bucco lingual width in three vertical distances from surface: 5mm, 10mm and 15mm B) Vertical distances between the superior border of mandibular canal and superior surface of alveolar bone. These measurements were compared with their counterparts in tomographic images. From this comparison we concluded that there is no significant difference between linear tomography and direct observation in measuring the distance between superior bone surface and superior border of mandibular canal (P>0.05). There is significant difference when we consider horizontal measurements with the exception of  buccolingual width in premolar area at the 5mm vertical distance from the surface which shows no significant differences (P> 0.05). The validity of tomographic technique is acceptable since there were no significant differences between different radiologists' observations and between one radiologist's observation in different sessions (P> 0.05).      

60 mesial roots of first and second mandibular molars and 60 buccal roots of first and second maxillary molars with curve angles ranging 10-40 degree were divided into 4 groups of 30. The canals were instrumented as follows: group 1, "step back +k-type file"; group 2, "step back + k-flex file"; group 3 "Passive step back + k-type file"; and grup 4, "Passive step back + k-flex type". Then the canal curve angles were measured again with the same method (P<0.01). There was significant difference between "Passive step back + K -flex type" compared with the other groups.    

This study evaluated the performance of a new bone substitute material, Neo-Os I for 1) ease of handling, 2) compatibility with bone and soft tissue, 3) stability of augmented over time and 4)development of untoward effects. Neo- Os was implanted in 40 patients by mean~ of impacted mandibular third molar removal and filling the alveolar socket by the Neo-Os particles. Results: The material was found to be easy to manipulate during oral surgery. Tissue and bone compatibility (defined as absence of inflammation and pus) was present in the 38/40 surgical sites. Radiograph study demonstrated that an average of 12 months is needed for resorption of Neo-Os I particles which did replaced by bone.    

160 patients with vital molars were selected and randomly divided into four experimental groups. After making anesthetic procedure, the occlusal surface of teeth were reduced about 0.5 to 0.75 mm, making access to the root canal (s), the working length (s) were determined and confirmed by inserting file (s)at 1mm shorter than radiographic apex. The canal(s) were prepared by step back technique and one of the below treatments were applied. Group one: Diclophenac sodium, Group two: Diphenhydrammine HCl1%, Group three: Normal saline, The access cavities were closed with 3mm thickness of the temporary filling material (coltosal). Patients were given pain and swellin questionnaires at intervals of 4h, 7/, 24l, 48h and one week. After one week teeth were laterally obturated by Guttapercha and AH26 root canal sealer. In terms of pain significant differences were seen between negative control and positive control group (p=0), Diclophenac sodium and Diphenhydrammine HCl 1% (p =0). Frequency of swelling was not equal between groups. Incidence of swelling was rare and there were significant differences between diclophenac sodium and saline (p=0).