Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:3 Issue: 4, Autumn 2009

Background and aims. Orientation of the occlusal plane is one of the most important clinical procedures in prosthodontic rehabilitation of edentulous patients. The aim of this study was to define the best posterior reference point of ala-tragus line for orientation of occlusal plane for complete denture fabrication.Materials and methods. Fifty-three dental students (27 females and 26 males) with complete natural dentition and Angel’s Class I occlusal relationship were selected. The subjects were photographed in natural head position while clenching on a Fox plane. After tracing the photographs, the angles between the following lines were measured: the occlusal plane (Fox plane) and the superior border of ala-tragus, the occlusal plane (Fox plane) and the middle of ala-tragus as well as the occlusal plane (Fox plane) and the inferior border of ala-tragus. Descriptive statistics, one sample t-test and independent t-test were used. P value less than 0.05 was considered significant.Results. There was no parallelism between the occlusal plane and ala-tragus line with three different posterior ends and one sample t-test showed that the angles between them were significantly different from zero (P < 0.05). However, the superior border of ala-tragus line had the lowest mean angle, 1.80° (3.12) and was almost parallel to the occlusal plane.Conclusion. The superior border of the tragus is suggested as the posterior reference for ala-tragus line.

Background and aims. The objectives of the present study were to investigate the prevalence and the position of enamel defects of primary teeth and hence to estimate the approximate time of an insult. Material and methods. 121 children aged 3 to 5 years were included in the study. The Modified Developmental Defects of Enamel Index was used to diagnose and classify the defects. The defects were categorized as hypoplasia, hypocalcification or a combination of them. Each tooth was investigated for occlusal/incisal, middle, cervical, incisomiddle, cervicomiddle and complete crown defects. Results. 55.37% of the children were affected by enamel defects, 23.96% being categorized as hypocalcification and 22.31% as hypoplasia. The enamel defects were more abundant in maxillary primary incisors and mandibular primary canines. Minimum involvement was seen in maxillary primary second molars and mandibular primary lateral incisors. The prevalence of cervical defects in maxillary primary incisors was significantly more than the middle or incisal defects (P < 0.05). The prevalence of incisal defects in mandibular primary incisors was significantly more than the middle or cervical defects (P < 0.05). Conclusions. The results revealed a considerable number of enamel defects which are multiple, symmetric and chronologically accordant with the estimated neonatal line in primary teeth of healthy children.

Background and aims. A carious lesion is the accumulation of numerous episodes of de- and remineralization, rather than a unidirectional demineralization process. Tooth destruction can be arrested or reversed by the frequent delivery of fluoride or calcium/phosphorous ions to the tooth surface. The present study compared and evaluated the remineralization potential of sodium fluoride and bioactive glass delivered through a bioerodible gel system.Materials and methods. Longitudinal sections of artificial carious lesions, created at the gingivofacial surface of 64 primary maxillary incisors were photographed under a polarized light microscope and quantified for demineralization. The sections were repositioned into the tooth form and randomly mounted in sets of four that simulated an arch form. The teeth were divided into 4 groups: 1) sodium fluoride films, 2) bioactive glass films, 3) control films placed interproximally and 4) non-treatment group. Following exposure to artificial saliva for 30 days, the lesions were again photographed and quantified as above. The recorded values were statistically analyzed using Student’s paired t-test for intragroup comparison, one-way ANOVA and Post-Hoc Tukey’s test for pairwise comparison.Results. The sodium fluoride and bioactive gel groups showed significant remineralization compared with the control groups (P < 0.001).Conclusion. Bioerodible gel films can be used to deliver remineralizing agents to enhance remineralization.

Background and aims. Several products have been marketed for disinfecting impression materials. The present study evaluated the effect of Deconex, Micro 10, Alprocid and Unisepta Plus sprays on Staphylococcus aureus and Candida albicans transferred to alginate and polyvinylsiloxane impression materials. Materials and methods. A total of 180 impressions of a maxillary model (90 alginate and 90 polyvinylsiloxane impressions) were taken for the purpose of this in vitro study. Half of the impressions were infected with Staphylococcus aureus and the other half were infected with Candida albicans. Then the microorganisms were cultured and their counts were determined. Subsequently, the impressions were divided into groups of 15 impressions each. Each group was disinfected with Deconex, Micro10, Alprocid and Unisepta Plus according to manufacturer's instructions except for the control group. The culturing procedure was repeated after disinfection and microbial counts were determined again. Data was analyzed by ANOVA and paired-sample t-test.Results. There were statistically significant differences in the means of S. aureus and C. albicans counts before and after the use of disinfectants (P < 0.05). The use of the four disinfectants reduced S. aureus counts to zero in 80% of the cases. There were no statistically significant differences in S. aureus count reductions between the four disinfectants evaluated (P = 0.31). Micro 10 was more effective on alginate; Deconex was more efficient for polyvinylsiloxane and Alprocid had a better efficacy in both impression materials in eliminating C. albicans (P < 0.05).Conclusion. All the disinfectants evaluated have high disinfecting postentials.

Background and aims. Digital radiographs have some advantages over conventional ones. Application of digital receptors is not routine yet. Therefore, there is a need for digitizing conventional radiographs. The aim of the present study was to compare the diagnostic accuracy of digitized conventional radiographs by scanner and camera in detection of proximal caries.Material and methods. Three hundred and sixteen surfaces of 158 extracted posterior teeth were radiographed. The radiographs were digitized using a digital camera and a scanner. Five observers scored the images for the presence and depth of caries. Histopathologic sections were the gold standard. Kappa agreement coefficient was used for statistical analysis.Results. Kappa agreement coefficients between the camera and the scanner and also between each one with the gold standard in detecting the depth of caries were 0.504, 0.557 and 0.454, respectively. In detection of caries, the indexes were 0.571, 0.553 and 0.527, respectively.Conclusion. Diagnostic accuracy of camera images in caries detection was more than that of scanned images, but there was also a moderate consistency between them. The consistency of detecting the presence of caries was more than that of detecting their depths. It seems that both digital cameras and scanners can be used interchangeably.

Background and aims. The majority of complete denture wearers are old. Clinical experience suggests that complete denture wearers have various disorders in their gustatory and olfactory senses due to disturbance of airways between the oral and nasal cavities caused by upper complete denture. The purpose of this study was to evaluate the effect of upper complete denture on gustatory and olfactory senses in denture wearers.Materials and methods. In this study, gustatory and olfactory senses in 30 patients (15 men and 15 women with a mean age of 52.93 ± 12.97 years) were evaluated three times: before complete denture insertion, three days after insertion and 1 month after that. Sucrose, citric acid, NaCl solution and distilled water (in two samples) were used to evaluate gustatory evaluation while mint- and cinnamon-flavored chewing gums were used for olfactory evaluation. Means and standard deviations were calculated and then compared between the different time intervals. P < 0.05 was considered significant.Results. The mean taste identification time was 5.23 ± 3.52 seconds before denture insertion, which decreased three days after insertion of denture and 1 month after use; however, these changes were not significant (P = 0.149). The mean time of flavor recognition increased after three days of insertion compared to the period before denture wear but decreased after 1 month; however, these changes were not significant (P = 0.792). In addition, the results revealed no significant differences in mean error in identification of taste and smell before and after denture insertion (P = 0.294).Conclusion. Denture wearing does not influence gustatory and olfactory senses.

Background and aims. Although wearing a white coat is an accepted part of medical and dental practice, it is a potential source of cross-infection. The objective of this study was to determine the level and type of microbial contamination present on the white coats of dental interns, graduate students and faculty in a dental clinic. Materials and methods. Questionnaire and cross-sectional survey of the bacterial contamination of white coats in two predetermined areas (chest and pocket) on the white coats were done in a rural dental care center. Paired sample t-test and chi-square test were used for Statistical analysis.Results. 60.8% of the participants reported washing their white coats once a week. Grading by the examiner revealed 15.7% dirty white coats. Also, 82.5% of the interns showed bacterial contamination of their white coats compared to 74.7% graduate students and 75% faculty members irrespective of the area examined. However, chest area was consistently a more bacteriologically contaminated site as compared to the pocket area. Antibiotic sensitivity testing revealed resistant varieties of microorganisms against Amoxicillin (60%), Erythromycin (42.5%) and Cotrimoxazole (35.2%). Conclusion. The white coats seem to be a potential source of cross-infection in the dental setting. The bacterial contamination carried by white coats, as demonstrated in this study, supports the ban on white coats from non-clinical areas.

Regional odontodysplasia (RO) is a rare developmental dental anomaly with an unknown etiology. It is more often seen in girls than boys. Treatment of RO depends on the individual case. The aims of treatment should include aiding mastication and speech, improving aesthetics, reducing the psychological impact of the anomaly, allowing normal jaw growth and development, and if possible protection of any erupted teeth which are affected. We present a rare case of RO together with the treatment modality undertaken.

The article entitled “Assessment of the etiologic factors of gingival recession in a group of patients in Northwest Iran” which appeared in J Dent Res Dent Clin Dent Prospect 2009; 3(3):90-93 did not list the fourth author’s name. The journal regrets this error. The correct list of authors of this article is as follows: Ardeshir Lafzi, Nader Abolfazli, Amir Eskandari, and Mehrnoosh Sadighi. Dr. Mehrnoosh Sadighi is a post-graduate student at the Department of Periodontics, Faculty of Dentistry, Tabriz University of Medi-cal Sciences.