مجله دانشکده دندان پزشکی اصفهان
سال هفتم شماره 3 (پیاپی 27، پاییز 1390)

Some dental procedures stimulate gag reflex. The majority of techniques to reduce the intensity or eliminate this problem have proved ineffective or time-consuming. Pomegranate (Punica granatum) peel contains tannic acid which has anesthetic effects. The aim of this study was to evaluate the use of pomegranate peel extract lozenges in controlling gag reflex during dental procedures. This study was a randomized double-blind controlled trial with convenient sampling procedure on 84 patients in the Faculty of Dentistry, Isfahan University of Medical Sciences. The subjects were equally and randomly divided into two case and control groups. Pomegranate peel extract (80% concentration) and placebo lozenges were provided. Gag reflex was evaluated before and after intervention by stimulation of soft palate and tonsils with a piece of tongue depressor. Data was analyzed and compared with SPSS 11 software using chi-squared and McNemar’s tests (α=0.05). Gag reflex significantly decreased in the case group in soft palate region (88.5%) (p value < 0.001) and tonsils (92.5%) (p value < 0.001). In the placebo group gag reflex decrease was not significant in the soft palate and tonsil areas (p value = 0.9). Gag reflex decreases exhibited statistically significant differences between the case and placebo groups (p value < 0.01). The results of this study showed that indicate pomegranate peel extract is effective in controlling gag reflex during dental treatment; however, more extensive clinical studies are necessary on the subject.

Tooth brushing with a toothpaste is the most frequent and important method to maintain oral hygiene. However, using such products has its side effects, including tooth abrasion. The aim of this study was to compare abrasiveness of aforeign whitening toothpaste and three similar Iranian brands.

In this in vitro experimental study four groups of enamel samples, each consisting of 6 samples, were prepared and embedded in acrylic blocks. The samples were 5×5×5 mm and were prepared from 24 sound extracted human anterior teeth. The initial surface profile for each specimen was calculated using a profilometer. The samples underwent a wear test in a V8 Cross Brushing machine using toothbrushes and a toothpaste solution. The samples were then dried and the surface profile was again calculated. The difference between the first and second profilometer calculations demonstrated wear for each specimen. Data was analyzed using the SPSS program by means of one-way ANOVA and repeated measures ANOVA (α=0.05).

According to repeated measures ANOVA, there were significant differences between means of profilometry before and after of abrasion (p value < 0.0001). However, this effect was not significant for toothpaste type (p value = 0.991). One-way ANOVA did not reveal any significant differences between means of differences before and after abrasion among the four groups.

According to the results there were no significant differences between enamel abrasion by Iranian toothpastes and a foreign one.

When there is no immediate access to dental laboratory for pouring dental impressions, impression materials with dimensional stability over time should be used. The aim of this study was to evaluate the effect of storage time on dimensional stability of casts poured from alginate impressions. In this experimental-laboratory study, a metal model containing two dies and acrylic impression trays were used to make five alginate impressions at each time interval using three different alginate brands [Hydrogum5 (Zhermack), Elastic Cromo (Spofadental), and Alginmax (Major)]. The impressions were kept in a humid environment for 0, 24, 48, 72, and 120 hours and then poured with Type III dental stone. Five dimensions were measured in each cast with a digital caliper: ED (distance between the two dies), H1 (height of the smaller die), H2 (height of the larger die), D1 (diameter of the smaller die), D2 (diameter of the larger die). The results were compared among groups with two-way ANOVA and a post hoc Tukey test (α=0.05). Dimensional stability of alginate impressions was dependent on both the material and time (p value < 0.05); however, their reciprocal interaction did not exhibit any significant relationship at the same interval (p value > 0.05). After 24 hours, dimensions of Elastic Cromo alginate only did not exhibit any statistically significant differences with the model (p value > 0.05). After 48 and 72 hours Hydrogum5 alginate only did not demonstrate any significant dimensional differences with the model (p value > 0.05). After 120 hours, Hydrogum5 alginate exhibited a significant difference with the model in H2 dimension. The results showed that Alginmax impressions must be poured immediately. Elastic Cromo impressions can be poured after 24 hours. The impression of these three kinds of impression materials did not exhibit any significant dimensional differences before 120 hours; however, they are not reliable for five-day usage.

Periodontitis is a chronic multi-factorial infectious disease characterized by irreversible destruction of collagen fibers and other matrix constituents of the gingival tissues and periodontal ligament, and resorption of alveolar bone around the teeth with periodontal pocket formation. Host response to periodontal disease includes production of different enzymes that are released by stromal, epithelial or inflammatory cells associated with cell injury and cell death, including aspartate aminotransferase and lactate dehydrogenase. The aim of this study was to compare aspartate aminotransferase and lactate dehydrogenase salivary levels in patients with generalized aggressive periodontitis and chronic mild-to-moderate periodontitis and healthy subjects with normal periodontium. In this experimental study, unstimulated saliva of 25 patients with mild-to-moderate periodontitis, 15 patients with aggressive periodontitis, and 25 subjects with healthy gingiva were collected. The mean aspartate aminotransferase and lactate dehydrogenase salivary levels were measured by RA-ST autoanalyzer system. Data were analyzed by ANOVA and Tukey test. The mean levels and standard deviations of lactate dehydrogenase salivary enzyme in generalized aggressive periodontitis, chronic mild-to-moderate periodontitis and control groups were 1713±88.4, 1492±65.4, 1108±34.5, respectively, with significant differences between the groups (p value < 0.05) The mean levels and standard deviations of aspartate aminotransferase salivary enzyme in generalized aggressive periodontitis, chronic mild-to-moderate periodontitis and control groups were 55.46±5.6, 47.04±3.3 and 32.04±2.3, respectively, with significant differences (p value < 0.05). Mean levels of aspartate aminotransferase and lactate dehydrogenase salivary enzymes in periodontal patients were higher than those in healthy subjects and these enzymes can be good markers for determining amount of destruction of periodontal tissues.

Thyroid gland is one of the critical organs during radiation in the head and neck region. The aim of this study was to compare absorbed radiation dose by skin in the thyroid area during spiral tomography and panoramic radiography by means of thermoluminance dosimetry (TLD). Thirty-six LiF (TLD-100) thermoluminescence dosimetry chips were utilized in this experimental in vitro study. One TLD chip was placed on the tube side and another was placed on the opposite side of the thyroid gland of a sliced anatomic Alderson head and neck phantom during panoramic radiography and spiral tomography. The dosimeters were read by a SOLARO 2A TLD reader twice followed by calculation of the absorbed dose. The results were analyzed by Wilcoxon’s test at a confidence interval of 95%. The mean dose for screen-film panoramic radiographs was 34 µGy in the left thyroid and 39 on the right side. With spiral tomography the thyroid gland received a mean dose of 30‒71 µGy. There were no statistically significant differences in the mean thyroid doses between anterior and posterior spiral tomography and panoramic examination (p value > 0.05). Skin absorbed radiation dose of a tomographic examination, which includes four sections with a specific thickness, are almost comparable to that with a panoramic radiographic technique.

Advanced untreated dental caries can cause pain and discomfort and influence nutrition and growth in children. The aim of this study was to evaluate dental caries status (dft) and body mass index (BMI) and their relationship in preschool children in Babol. This descriptive-analytical, cross-sectional study was carried out on 600 healthy preschool children aged 3‒6 years in kindergartens of Babol. After measuring weight with a standard weighing machine (SECA) and height with a standard graduated ruler, BMI was calculated and entered in the curve of standards to determine percentages. In addition, dft was determined according to WHO criteria. Children with known systemic diseases were excluded from the study. Data was analyzed by qui-squared test and ANOVA. Of 600 children, 206 (34.3%) children were caries-free. Regarding BMI percentages, 62% of children were normal, 15.3% were overweight and at risk of being overweight, and 22.7% were underweight. The relationship between mean of BMI according to d and f was not significant but there was an increase in dental caries with an increase in body weight (p value = 0.002); however, there was no significant relationship between weight and the number of fillings (p value = 0.08). Under the limitations of this study, the least and highest number of decay processes and fillings were found in “underweight” and “at risk of overweight” children, respectively. There was a significant increase in caries rate with an increase in the mean of body weight.

In most cases after periodontal surgery, the surgical area is covered with surgical packs. Recent studies suggest that use of periodontal packs after periodontal flap surgery is not necessary and some patients may be irritated by them. The aim of this study was to determine microbiological contamination of a periodontal pack (Coe-pak) by determining microbial colony counts of surgical sutures after modified Widman flap surgery. In this clinical trial, thirty-two patients needing periodontal surgeries at least in two quadrants of jaws were selected. In one quadrant, after surgery the surgical area was covered with periodontal pack randomly and the other quadrant was left without any dressing. After a week the sutures were removed and microbiological colony counts were determined. Finally microbial colony counts in the two groups were compared between the two groups by paired sample test using SPSS software (α=0.05). The mean colony counts with and without periodontal pack were 10187±2900 and 9812±3042, respectively, with no statistically significant differences between the two groups (p value = 0.602). The results of this research showed that sutures have microbial contamination with or without use of periodontal packs and these materials have no effect on microbial contamination.

In recent years, computed tomography (CT) scan has become an alternative to conventional radiography; however, the use of ultrasound in detecting zygomatic arch fractures has been rarely evaluated. The aim of this study was to evaluate accuracy of ultrasonography in the diagnosis of zygomatic arch fractures. Fifteen patients (9 men and 6 women) with clinical signs of midfacial fractures, whose CT scan findings showed unilateral zygomatic arch fracture, were selected. All the patients underwent bilateral ultrasound examinations. All the sonographic techniques were carried out and interpreted by the same sonologist who was not aware of the CT results. Data were analyzed to determine sensitivity and specificity of ultrasonography in the diagnosis of zygomatic arch fractures. Ultrasound assessed the fractured arches with a sensitivity of 100% (15 of 15 patients, with no false negatives) and the un-fractured arches with a specificity of 100% (no false positives). Based on the results of the present study ultrasound is a useful diagnostic tool for zygomatic arch fractures in initial investigations, and can help reduce the total number of diagnostic radiographic procedures and overall radiation exposure.

The oral cavity is always exposed to variable chronic and persistent irritations because of its special anatomic location and its various functions, such as chewing. Therefore, many lesions, referred to as reactive or tumor-like lesions, occur in the mouth as a result of these chronic and persistent irritations. Chronic irritating factors of the oral cavity include microbial, chemical and pharmaceutical agents, mechanical traumas, and endocrinal and hormonal factors. Given the role of local irritating factors, such as calculus, dental plaque and local traumas in inducing these lesions, elimination of these factors and agents should be undertaken by dental practitioners to prevent incidence or recurrence of such lesions. In addition, treatment of these lesions is possible by dental practitioners in many cases. Therefore, knowledge about differential diagnosis, treatment plan and prognosis of these lesions is mandatory for dental practitioners.Key words:

The aim of this literature review was to evaluate the efficacy of subepithelial connective tissue grafts (SCTG) in comparison with other commonly used techniques for the coverage of denuded root surfaces. An electronic search was carried out in Medline and Pubmed for randomized controlled clinical trials with at least 6-month follow-ups comparing SCTG with other techniques for the treatment of gingival recession from 1994 up to August 2010. The studies eligible to be included in this review had the following criteria: (a) Miller’s Class I or Class II recession with a depth of at least 2 mm; (b) recession areas containing teeth with no caries or restorations; and (c) at least 10 participants per group at final examination. Of all the studies evaluated, 36 studies were considered relevant. The results showed that decreases in recession depth subsequent to SCTG were significantly greater compared to those with acellular dermal matrix grafts and guided tissue regeneration. Regarding clinical attachment level changes, differences between the groups were not significant. In relation to changes in the keratinized tissue (KT), the results showed a significantly higher gain in the width of KT with SCTG compared to GTR. The results of this review showed that subepithelial connective tissue grafts provide significantly better root coverage, higher clinical attachment gain and greater keratinized tissue width.

Since it is difficult to choose the best treatment plan for molar-incisor hypomineralization (MIH), which involves special considerations, the aim of this study was to evaluate MIH etiology and introduce the best treatment plan.Review report: PubMed, Scopus, Google Scholar, and Iran Medex searches were run for the published data from 1970 to 2010 with mesh terms of molar, incisor, and molar-incisor hypomineralization to collect relevant data.

MIH is a term to describe a condition in which one or more of the first permanent molars and often at least one incisor are involved, which is distinct from other disorders. Several factors have been implicated in its etiology, which include environmental contaminants, medical problems (prenatal, perinatal, postnatal) and genetic factors. Treatment entails a wide range of modalities from preventive measures to full crowns.

Since MIH is a well recognized and prevalent clinical condition, children at risk as a result of repeated episodes of disease during the first year of life or children with opacities on erupting molars and incisors should be monitored carefully and should undergo regular dental visits and care. It appears it is necessary for dental practitioners to have a sound knowledge about the etiology and proper treatment plans for the condition.