Effect of virtual versus traditional education on theoretical knowledge and reporting skills of dental students in radiographic interpretation of bony lesions of the jaw.

BACKGROUND: This study aimed to compare the effect of virtual and traditional education on theoretical knowledge and reporting skills of dental students in radiographic interpretation of bony lesions of the jaw. METHODS: This experimental study evaluated 39 dental students who had not received any instruction regarding radiographic interpretation of bony lesions of the jaw. They were randomly divided into two groups of virtual (n = 20) and traditional education (n = 19) and matched in terms of their grade point average (GPA). The virtual group received a virtual learning package while the traditional group received traditional classroom instruction for 6 one-hour sessions. Similar contents were taught to both groups by the same mentor. All students participated in a theoretical test with multiple-choice questions and an objective structured clinical examination (OSCE). Similar exams were also held 2 months later to assess knowledge retention. Data were analyzed using independent sample t-test and repeated measures ANOVA. RESULTS: The mean scores of theoretical test (P < 0.05) and OSCE (P > 0.05) in the virtual education group (16.60 ± 0.91 and 15.13 ± 0.78) were higher than those in the traditional education group (14.89 ± 0.99 and 14.71 ± 0.92). In both methods of instruction, the mean scores of theoretical test and OSCE at 2 months were lower than the scores acquired immediately after instruction but this difference was not statistically significant (P > 0.05). Type of education had a significant effect on the theoretical test score (P < 0.001) but had no significant effect on the clinical score (P = 0.072). CONCLUSIONS: Virtual learning was superior to traditional lecture-based method for enhancement of knowledge acquisition in radiographic interpretation of bony lesions of the jaw. However, to improve our students' reporting skills, we need to revise our virtual educational program so that the students have more opportunities to engage in reporting skills.

Efficacy of diode and CO2 lasers along with calcium and fluoride-containing compounds for the remineralization of primary teeth.

BACKGROUND: This study aimed to assess the efficacy of a 980-nm diode and 10.6-µm CO2 laser accompanied by tricalcium phosphate-5% sodium fluoride (fTCP) and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) for the remineralization of primary teeth. METHODS: In total, 117 extracted primary anterior teeth were randomly divided into eight experimental and one control group: (I) control (polished enamel), (II) fTCP varnish, (III) fTCP + diode laser, (IV) fTCP + CO2 laser, (V) CPP-ACP, (VI) CPP-ACP + diode laser, (VII) CPP-ACP + CO2 laser, (VIII) diode laser, and (IX) CO2 laser. The microhardness of 12 samples in each group and the enamel porosity of one sample in each group were assessed before and after demineralization and 28 days after remineralization. Data were analysed using two-way ANOVA. RESULTS: Significant differences existed in microhardness (P = 0.004) and percentage of remineralization (P < 0.001) after remineralization among the material groups such that the highest mean was noted in the CPP-ACP group. No significant difference was noted in microhardness (P = 0.052) or percentage of remineralization (P = 0.981) after remineralization among the laser groups. In all groups, porosities increased after demineralization and slightly decreased after remineralization; the greatest reduction in porosity of the material groups was noted in the fTCP group, and the CO2 group among the laser groups. The interaction effect of materials and lasers was not significant (P > 0.05). CONCLUSION: The highest microhardness was achieved after remineralization with CPP-ACP. The efficacy of the diode and CO2 lasers was the same. No synergistic effect was found between materials and lasers. TRIAL REGISTRATION: This is not a human subject research.

Signs and symptoms associated with primary tooth eruption: a clinical trial of nonpharmacological remedies.

BACKGROUND: To evaluate disturbances in primary tooth eruption and their management with nonpharmacological remedies. METHODS: In this nonrandomized clinical trial, 270 children aged between 8 and 36 months were selected and divided into 5 groups with 54 children initially enrolled in each group. The children were seen during an 8-day period during tooth eruption. At each appointment data were recorded from oral examination, tympanic temperature measurement and a questionnaire. The five methods used as remedies to reduce teething symptoms were: 1) cuddle therapy, 2) ice, 3) rubbing the gums, 4) teething rings and 5) food for chewing. Teething symptoms, the type of erupted tooth, symptoms of recovery and the mother's satisfaction with treatment were evaluated. RESULTS: Two hundred and fifty four children (mean age 16 ± 7.2 months) completed the study. The most frequent teething symptoms were drooling (92%), sleep disturbances (82.3%) and irritability (75.6%). These symptoms were more pronounced in low birth weight children (p > 0.05). Canine eruption led to more loss of appetite than incisor (p = 0.033) or molars eruption (p = 0.014). Low grade increases in body temperature were observed only on the day of eruption (36.70 ± 0.39 °C), when body temperature was significantly different compared to the day before and the day after eruption (both p < 0.001). There was no significant correlation between fever as reported by mothers and temperature readings obtained by the investigators. The most favorable results for time to recovery and the mother's satisfaction were seen when teething rings were used, followed by cuddle therapy and rubbing the gums. CONCLUSIONS: There was no association between teething and symptoms such as fever or diarrhea. Low birth weight children may have more teething symptoms. Teething rings, cuddle therapy and rubbing the gums were the most effective methods to reduce symptoms. TRIAL REGISTRATION: Iranian Registry of Clinical Trials: code IRCT201211127402N3.

The accuracy of a designed software for automated localization of craniofacial landmarks on CBCT images.

BACKGROUND: Two-dimensional projection radiographs have been traditionally considered the modality of choice for cephalometric analysis. To overcome the shortcomings of two-dimensional images, three-dimensional computed tomography (CT) has been used to evaluate craniofacial structures. However, manual landmark detection depends on medical expertise, and the process is time-consuming. The present study was designed to produce software capable of automated localization of craniofacial landmarks on cone beam (CB) CT images based on image registration and to evaluate its accuracy. METHODS: The software was designed using MATLAB programming language. The technique was a combination of feature-based (principal axes registration) and voxel similarity-based methods for image registration. A total of 8 CBCT images were selected as our reference images for creating a head atlas. Then, 20 CBCT images were randomly selected as the test images for evaluating the method. Three experts twice located 14 landmarks in all 28 CBCT images during two examinations set 6 weeks apart. The differences in the distances of coordinates of each landmark on each image between manual and automated detection methods were calculated and reported as mean errors. RESULTS: The combined intraclass correlation coefficient for intraobserver reliability was 0.89 and for interobserver reliability 0.87 (95% confidence interval, 0.82 to 0.93). The mean errors of all 14 landmarks were <4 mm. Additionally, 63.57% of landmarks had a mean error of <3 mm compared with manual detection (gold standard method). CONCLUSION: The accuracy of our approach for automated localization of craniofacial landmarks, which was based on combining feature-based and voxel similarity-based methods for image registration, was acceptable. Nevertheless we recommend repetition of this study using other techniques, such as intensity-based methods.

Comparative evaluation of the efficacy of three methods of delivering calcium hydroxide into the root canal.

BACKGROUND: Calcium hydroxide, due to its favorable properties, such as an antimicrobial effect as well as its ability to dissolve necrotic tissues, inhibit tooth resorption and stimulate the formation of a hard tissue barrier, is widely used in root canal treatment. OBJECTIVES: The objective of this study was to compare the efficacy of 3 methods of delivery of calcium hydroxide into the canals. MATERIAL AND METHODS: This in vitro experimental study was performed on acrylic resin blocks with simulated curved canals (curvature of 24° and 44°). Calcium hydroxide was delivered into the canals with 3 different instruments : a hand file, a Lentulo and a rotary file. The data was analyzed using the three-way analysis of variance (ANOVA) and Tukey's test. RESULTS: The density of calcium hydroxide was significantly different among the 3 groups (p < 0.001). The manual delivery technique resulted in the lowest and using a rotary file in the highest density of calcium hydroxide (p < 0.001). The mean density of calcium hydroxide was significantly higher in the canals with curvature of 24°, irrespective of the delivery method (p < 0.001). The lowest mean density of calcium hydroxide was noted at 1 mm and 3 mm from the apex, whereas the highest mean density was noted at 11 mm from the apex, irrespective of delivery method (p < 0.001). CONCLUSIONS: A rotary file seems to be the most efficient instrument for delivering calcium hydroxide into the canals, especially into the apical region of canals with greater curvature.

Accuracy of software designed for automated localization of the inferior alveolar nerve canal on cone beam CT images.

OBJECTIVES: The aim of this study was to design and evaluate a new method for automated localization of the inferior alveolar nerve canal on CBCT images. METHODS: The proposed method is based on traversing both panoramic and cross-sectional slices. For the panoramic slices, morphological skeletonization is imposed, and a modified Hough transform is used while traversing the cross-sectional slices. A total of 40 CBCT images were randomly selected. Two experts twice located the inferior alveolar nerve canal during two examinations set 6 weeks apart. Agreement between experts was achieved, and the result of this manual technique was considered the gold standard for our study. The distances for the automated method and those determined using the gold standard method were calculated and recorded. The mean time required for the automated detection was also recorded. RESULTS: The average mean distance error from the baseline was 0.75 ± 0.34 mm. In all, 86% of the detected points had a mean error of <1 mm compared with those determined by the manual gold standard method. CONCLUSIONS: The proposed method is far more accurate and faster than previous methods. It also provides more accuracy than human annotation within a shorter time.

Efficacy of calcium- and fluoride-containing materials for the remineralization of primary teeth with early enamel lesion.

The aim of the study was to determine the efficacy of different products containing fluoride, calcium and phosphate for enamel remineralization in eroded primary teeth. A total of 90 sound primary canine teeth were randomly divided into 5 groups of 18 teeth each: 1) control (polished enamel), 2) 5% DuraShield sodium fluoride varnish, 3) 500 ppm fluoridated toothpaste, 4) casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) cream, and 5) Clinpro White varnish containing functionalized tri-calcium phosphate (fTCP). Enamel microhardness (EMH) was measured in all samples before and after demineralization and after 28 days of remineralization. Also 8 samples in groups 2 to 5 and four samples of sound and demineralized enamel were examined with atomic force microscopy (AFM). All data were analyzed with one-way ANOVA (p<0.05). Mean microhardness of demineralized enamel was significantly lower than in enamel at baseline (p<0.001). Remineralization significantly increased microharness in groups 2 to 5 compared to the control group (p<0.001). Percent EMH after remineralization with CPP-ACP was significantly higher than after fTCP (p=0.029), toothpaste (p< 0.001) or fluoride varnish (p<0.001); however, there was no significant difference between toothpaste and fluoride varnish (p=0.062). Microhardness increased more after fTCP treatment than after treatment with sodium fluoride varnish (p<0.001) or fluoridated toothpaste (p=0.045). AFM images showed that enamel roughness decreased most after treatment with fTCP, followed by CPP-ACP, toothpaste and fluoride varnish. The efficacy of CPP-ACP cream for remineralizing eroded enamel was greater than fluoride toothpaste, fluoride varnish or fTCP varnish.