Search

Introdution: Although oral and dental diseases may occur in unexpected or even emergency conditions, but some of the diagnosis and treatments can be algorithmically done following some guidelines. The development and implementation of a system that provides users with a record of history and a proposal of required actions can be not only efficiently practical, but also virtually simple. Materials and method: A system made up of web and mobile apps is proposed and evaluated for screening and self-care of oral and dental problems and for providing advice on dental emergencies and therapeutic measures. This system was developed and made available to users under the name of 'Dandanyar'. The data were then collected from Dandanyar users and analyzed based on the selected statistical population for evaluating their satisfaction. Results: The evaluation results showed that more than 90 % of specialists had a positive attitude towards application effectiveness. On the other hand, clients expressed their satisfaction with various aspects of the application in more than 80 % of cases. Conclusion: The importance of using such systems is highlighted in the Covid-19 pandemic condition where certain health protocols must be followed. For instance, people must avoid unnecessary traveling and limit their referrals to medical centers especially dental clinics due to the high volume of aerosols produced during dental treatment procedures.

Background: This study aimed to evaluate the impact of photodynamic therapy (PDT) using two photosensitizers, methylene blue and indocyanine green, on the microtensile bond strength of a universal adhesive to caries-affected dentin. Methods: The occlusal enamel of 60 third molars was cut to expose the inner one-third of the dentin. Artificial caries were induced through a pH cycling process. The samples were divided into three groups: M (Methylene blue+ diode laser), I (Indocyanine green agents+ diode laser irradiation), and control. Each group was further divided into two subgroups according to the adhesive protocol (self-etch, total-etch). After restoring with Gradia composite resin, teeth were sectioned and exposed to 5000 thermal cycles. Microtensile bond strength was measured using a universal testing machine. The data were subjected to two- and one-way ANOVA and paired comparisons were performed by the Tamhane and Tukey tests. Results: The study found significant effects of the photosensitizer, etching pattern, and their interactions on the microtensile bond strength of composite resin to caries-affected dentin (P < 0.001). In the self-etching mode, PDT with indocyanine green exhibited significantly higher bond strength values compared to PDT with methylene blue (P = 0.001) and the control groups (P < 0.001). However, no significant differences were observed in the total-etch mode. (P = 0.54). Conclusions: The etching mode played a more significant role in the bond strength when using the universal adhesive alongside PDT with methylene blue and indocyanine green. Employing two photosensitizers in PDT during the self-etch mode significantly increased the bond strength values.

Background: The present study aimed to determine the cumulative effect of two photodynamic therapy methods with methylene blue and indocyanine green and two topical fluoride therapy methods with fluoride varnish and silver diamine fluoride alone and in combination on the microhardness and topography of demineralized enamel and cementum surfaces. Materials and methods: Seventy-two sound human teeth were selected, and their buccal and lingual surfaces were assigned to two main groups of enamel and cementum using simple randomization. The initial surface hardness (SH) of the enamel and cementum in each sample was determined using a micro-Vickers hardness tester using a 200-g force in 10 s. Then artificial caries was induced by immersion in a demineralizing/remineralizing solution (i.e., each tooth provided two samples, one on the buccal aspect and the other on the lingual aspect). Each enamel/cementum main group was divided into two subgroups using simple randomization based on the local fluoride type (fluoride varnish and silver diamine fluoride) and the type of the photosensitizer agent (methylene blue and indocyanine green). Finally, 16 groups were achieved (n = 9). The final surface hardness of the enamel and cementum samples was determined as described above. Finally, the sample surfaces were prepared for the surface topography evaluation under a scanning electron microscope. The baseline microhardness was compared between the 16 study groups in the first step using one-way ANOVA. Then, three-way ANOVA was used to evaluate the effect of fluoride, laser, and surface (enamel and cementum) on microhardness. Results: All the groups exhibited decreased microhardness due to the induction of artificial caries. In both main groups of enamel and cementum, the lowest decrease in microhardness was recorded with combined photodynamic therapy and methylene blue photosensitizer material and fluoride varnish (15.1 % for cementum and 16.7 % for enamel), and the highest decrease in microhardness was recorded in the methylene blue group (35.7 % for cementum and 34.9 % for enamel). Conclusion: The combination of photodynamic therapy with the photosensitizer substance methylene blue or indocyanine green together with fluoride varnish or silver diamine fluoride is effective on the remineralization of demineralized enamel and cementum. Although there is no difference between the combination of photodynamic therapy with fluoride varnish compared to fluoride varnish alone, both of these treatments are more effective than using photodynamic therapy alone.

Objectives: This study assessed the effects of blue and Er:YAG lasers, fluoride varnish, and their combination on microhardness, and calcium and phosphorus content of demineralized enamel. Materials and Methods: The primary Vickers microhardness of 28 third molars was measured and their enamel calcium and phosphorous content was quantified by energy-dispersive X-ray spectroscopy. They were then randomly assigned to five groups of 5% sodium fluoride (NaF) varnish, 445nm blue laser, Er:YAG laser, 5% NaF + 445nm blue laser, and 5% NaF + Er:YAG laser. The teeth then underwent pH-cycling to induce caries-like lesions. The surface microhardness of the teeth and the calcium and phosphorous content of demineralized enamel were measured again. Data were analyzed by one-way ANOVA and Tukey’s test (alpha=0.05). Results: NaF, NaF-diode laser, and NaF-Er:YAG laser groups experienced a significant increase in microhardness of demineralized enamel close to the baseline value (P

Abstract Background Dental caries, also known as tooth decay, is a widespread and long-standing condition that affects people of all ages. This ailment is caused by bacteria that attach themselves to teeth and break down sugars, creating acid that gradually wears away at the tooth structure. Tooth discoloration, pain, and sensitivity to hot or cold foods and drinks are common symptoms of tooth decay. Although this condition is prevalent among all age groups, it is especially prevalent in children with baby teeth. Early diagnosis of dental caries is critical to preventing further decay and avoiding costly tooth repairs. Currently, dentists employ a time-consuming and repetitive process of manually marking tooth lesions after conducting radiographic exams. However, with the rapid development of artificial intelligence in medical imaging research, there is a chance to improve the accuracy and efficiency of dental diagnosis. Methods This study introduces a data-driven model for accurately diagnosing dental decay through the use of Bitewing radiology images using convolutional neural networks. The dataset utilized in this research includes 713 patient images obtained from the Samin Maxillofacial Radiology Center located in Tehran, Iran. The images were captured between June 2020 and January 2022 and underwent processing via four distinct Convolutional Neural Networks. The images were resized to 100 × 100 and then divided into two groups: 70% (4219) for training and 30% (1813) for testing. The four networks employed in this study were AlexNet, ResNet50, VGG16, and VGG19. Results Among different well-known CNN architectures compared in this study, the VGG19 model was found to be the most accurate, with a 93.93% accuracy. Conclusion This promising result indicates the potential for developing an automatic AI-based dental caries diagnostic model from Bitewing images. It has the potential to serve patients or dentists as a mobile app or cloud-based diagnosis service (clinical decision support system).

Aim. The aim of this study was to assess the color changes in artificially induced incipient caries after photodynamic therapy (PDT) using different concentrations of methylene blue and toluidine blue, along with irrigation using water and hypochlorite. Materials and Methods. Forty-two sound human premolar teeth were used to create two artificial incipient carious lesions. One lesion was placed on the buccal surface and the other on the lingual surface. The color of these artificial incipient carious surfaces was determined using the CIE L ∗a ∗b ∗ color system. The teeth were then randomly assigned to 12 groups (n = 7) based on the PDT method. These methods included methylene blue with concentrations of 50, 100, and 150 µg/mL, followed by water irrigation, methylene blue with concentrations of 50, 100, and 150 µg/mL, followed by hypochlorite solution irrigation, toluidine blue with concentrations of 50, 100, and 150 µg/mL, followed by water irrigation, and toluidine blue with concentrations of 50, 100, and 150 µg/mL, followed by hypochlorite solution irrigation. The teeth underwent a colorimetry procedure again, and the resulting color changes were calculated. A three-way ANOVA was performed to analyze the effects of laser wavelength, concentration of the light-absorbing material, and irrigation solution on ΔE. Results. The results showed that the color changes caused by toluidine blue photosensitizer at a concentration of 100 µg/mL, with both water and hypochlorite irrigation, were not noticeable to the naked eye (ΔEwater = 3.04, ΔEhypochlorite = 2.00). However, in the other study groups, the color changes were perceptible (ΔE > 3.3). There were no significant differences in ΔE between different concentrations of methylene blue and toluidine blue when using either water or hypochlorite irrigation (P >0.05). A significant difference was observed between methylene blue and toluidine blue at a concentration of 100 µg/mL with water irrigation (P=0.006). Additionally, a significant difference was found between methylene blue and toluidine blue at a concentration of 100 µg/mL with hypochlorite irrigation (P=0.049). However, no significant differences were observed between methylene blue and toluidine blue at other concentrations with either water or hypochlorite irrigation (P >0.05). Conclusion. In conclusion, tooth color in teeth with incipient caries did not change significantly after PDT using toluidine blue (the photosensitizer) at a concentration of 100 µg/mL with either water or 1% hypochlorite solution irrigation for 5 s.

Abstract Objective Tooth enamel has opalescence and fluorescence, which should be mimicked by esthetic dental restorations. The purpose of this study was to compare the effects of glazing and polishing on the opalescence and fluorescence of dental ceramics. Materials and Methods Twenty‐four discs were fabricated of feldspathic, IPS e.max, zirconia, and Enamic ceramics with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 12). Of the discs fabricated with 0.5 and 1 mm thicknesses, half of them were glazed and the remaining half were polished (n = 6). Opalescence was calculated as the difference in yellow‐blue (CIE ∆b*) and red‐green (CIE ∆a*) color axes between the transmitted and reflected colors. The fluorescence of specimens was measured by a novel technique. Data were analyzed using two‐way analysis of variance at a 0.05 level of significance. Results In all groups (except for the Enamic ceramic), the mean opalescence of polished specimens (e.max = 2.704, feldspathic = 1.67, zirconia = 3.143) was higher than that of glazed specimens (e.max = 2.163, feldspathic = 1.016, zirconia = 2.690). The mean opalescence of glazed Enamic specimens (2.140) was higher than that of polished specimens (1.308). The fluorescence of glazed and polished specimens was not significantly different. Conclusion Surface treatment (glazing/polishing) affects the opalescence, but not the fluorescence of dental ceramics evaluated in this study.

Introduction: Covid-19 pandemic has underscored the importance of e-learning. This study endeavors to determine the extent and the way of using mobile learning amongst dental students. Methods: This descriptive study is cross-sectional. The data were collected through conducting a valid and reliable questionnaire. The population were 220 dental students from Tehran University of medical science who were randomly assigned and agreed to participate and complete the questionnaire. Results: 216 copies of questionnaire were collected. Of these, 108 students (50%) used their phones to use educational software. 168 students (77.8%) used social networks to learn dental courses. 214 students (98.2%) stated that smartphones have increased their access to educational data. 206 students (95.4%) were of the opinion that smartphones help them learn more independently. 189 students (87.5%) stated that it is necessary to employ more smartphones in higher education. Conclusion: Mobile learning is common amongst dental students of Tehran University of medical sciences. Different features of mobile are used in dental education, Mobile learning in dental education is can be optimized.

Introduction. Bleach-shade composite resins were recently introduced to the market due to the high demand of patients for whiter teeth. This study sought to compare four stain removal methods for bleach-shade composite resins. Materials and Methods. Seventy-two discs were fabricated from each of the Filtek Z350 XT and Gradia XBW composite resins and immersed in coffee or sour cherry juice staining solutions. Each group was then divided into four subgroups to assess the efficacy of four stain removal methods (finishing with soft-lex disk “brush with pumice” bleaching with carbamide peroxide 16%, bleaching with hydrogen peroxide 40%). The color of each specimen was measured by Easyshade spectrophotometer, and data were analyzed using SPSS 25 statistical package for social sciences. Results. The home-bleaching technique was more effective than the office-bleaching and pumice for the removal of sour cherry juice stain (ΔE = 1.93) and coffee stain (ΔE = 3.32) from Gradia composite discs, almost returning the baseline original color. The Sof-Lex discs were more effective than the pumice for the removal of sour cherry juice stain (ΔE = 4.11) and coffee stain (ΔE = 4.93) from Z350 composite discs but not return the baseline original color. Conclusions. Filtek Z350 had more discoloration than Gradia Direct. The different materials and solutions reacted differently to the four stain removal methods. In GCJ group after all stain removal methods, ΔE reduced to a clinically acceptable level.

Objectives: This study aimed to develop a new method for measurement of florescence and compare the fluorescence of some clinical dental ceramics in different thicknesses. Materials and Methods: Forty-eight samples of feldspathic (Vita VM9, A2), IPS e.max (Ivoclar HT, A2), zirconia (Korox Zircostar, A2) and Enamic (Vita A2) ceramics were used in this study in 0.5 and 1 mm thicknesses. The fluorescence of the samples was measured by using a developed technique. The results were analyzed by two-way ANOVA and Duncan post-hoc test. P

Background: Despite the improvements in optical properties of composite resins, their color stability is still a matter of concern. This study aimed to assess the curing time and intensity and polishing technique on color stability of bleach-shade composite resins. Materials and Methods: In this in vitro, experimental study, 128 discs (1 mm × 8 mm) were fabricated from two composite resins. The specimens fabricated from each composite were assigned to 8 subgroups (n = 8) based on the curing time and intensity and polishing with polishing points or discs. After polishing, the color parameters of specimens were measured by EasyShade spectrophotometer according to the CIEL* a*b* color system. The specimens were then immersed in tea solution, and their color parameters were measured again. Color change (ΔE) was calculated and analyzed at 0.05 level of significance. SPSS 25 was used for data analysis. Univariate four-way ANOVA was applied to assess the effects of composite type, curing time, curing intensity, and technique of polishing on ΔE of composite resins. Since the interaction effects were significant, subgroup analysis was performed by t-test. The level of significance for this test was set at 0.05. Results: The effects of curing intensity and polishing technique were significant on ΔE (P < 0.05). Filtek Z350 XBW composite specimens polished by polishing points experienced lower color change than those polished with discs. The minimum ΔE of Gradia XBW composite was recorded in specimens that underwent high-intensity curing for 20 s and were polished with polishing points while the maximum ΔE was recorded in specimens that underwent high-intensity curing for 20 s and were polished with discs. Conclusion: In all groups except on (Filtek, polishing with Disk, curing time = 20 s), high-intensity curing and polishing with polishing points were more effective and caused lower color change compared with low-intensity curing and polishing with discs.

Objective: To evaluate the association of perceived stress and dental work-related concerns regarding to COVID-19 by mediating role of cognitive flexibility among dentists during pandemic outbreak of COVID-19 in Iran. Methods: This study was a cross sectional survey conducted by means of a confidential on-line survey on 174 Iranian dentists. COVID-19 related questions were divided to three parts: dentists’ perspective about their career future, virus contagion and concerns of getting infected COVID-19 from patients, and paucity of information and facilities to control the spread of the virus. Perceived stress and psychological flexibility were assessed by PSS (Cohen et al., 1983) and CFI (Dennis et al., 2010). To analyze data path analysis method was used. Results: Perceived stress significantly predicted psychological flexibility (both alternatives and control subscales) and COVID-19 factors related to dental work In addition, control subscale significantly predicted dentists’ concerns toward their career future and fear of COVID-19 contagion. Hence, control subscale of cognitive flexibility mediated the relationship of perceived stress and professional concerns of dentists during COVID-19 pandemic. Conclusion: Given these results, elevated stress during an infectious disease outbreak can effect (have impact on) perceived stress and professional concerns among dentists. Different aspects of dentists’ lives can be affected by those concerns and stress. Interventions to enhance the cognitive flexibility should be applied to reduce the psychological burden of the crisis for dentists.

Background: Small chipping or fracture of ceramic restorations may be repaired by composite resin instead of replacing the restoration. This method is faster and cheaper compared to restoration replacement. Several strategies have been suggested to obtain a high repair shear bond strength (SBS). This study aimed to assess the efficacy of some new ceramic surface treatments (laser and universal adhesive) to enhance the repair bond strength of composite resin to ceramic compared to the conventional method. Materials and Methods: This in vitro study evaluated 80 IPS Empress Esthetic ceramic plates in eight groups (n = 10). The ceramic surface was polished with 320-grit silicon carbide paper under running water, rinsed with water spray for 10 s and dried. The samples were then divided into two subgroups for mechanical surface preparation with hydrofluoric (HF) acid and Er: YAG laser (2 W, 200 m J, 10 Hz, 10 s). Each group was divided into two subgroups for use/no use of silane. The conventional or universal adhesive was then applied on the samples in each subgroup. Composite cylinders were bonded to the ceramic surface using plastic tubes. The samples were stored in distilled water at 37°C for 24 h and subjected to an SBS test. Data were analyzed using one-way ANOVA (P < 0.05). Results: The interaction effect of variables on SBS was significant. Maximum SBS was noted in HF acid + silane + conventional adhesive group (mean: 12.0481 MPa). Minimum SBS was noted in the laser + conventional adhesive group (mean: 2.5766 MPa). Surface treatment with HF acid yielded significantly higher SBS than laser (P < 0.001). The interaction effect of conventional/universal adhesive and use/no use of silane on SBS was statistically significant. Conclusion: The repair SBS was higher in groups treated with HF acid compared to laser. Ceramic surface treatment with HF plus silane plus conventional adhesive yielded a higher SBS as well as HF plus Universal adhesive. Thus, the application of silane as a separate step can be omitted in the repair of ceramic restorations with universal adhesives.

Background: Studies on the efficacy of adaptive e-learning in dentistry are limited. This study aimed to compare the efficacy of linear and adaptive electronic continuing medical education (CME) courses about dental bleaching. Methods: This quasi-experimental study using a post-test control group design evaluated the efficacy of an electronic CME course on dental bleaching offered to 60 dentists who were non-randomly allocated in two linear and adaptive groups (n=30). One training session was held for participants of both the intervention and the control groups. At the end of the course, the learners participated in a post-test and completed a satisfaction questionnaire. SPSS 23 was used to analyze the results. An independent t test was used to assess the effect of type of intervention on the outcome of education, and Pearson’s chi-square test was applied to assess the effect of the intervention on participants’ satisfaction. Results: The mean post-test scores of participants were 6.33±1.47 for the linear group and 6.40±2.31 for the adaptive group. The mean satisfaction scores of participants were 4.02±0.53 for the linear group and 4.15±0.42 for the adaptive group. According to an independent t-test, the two groups were not significantly different in terms of post-test score (P=0.7) or level of satisfaction (P=0.2). Conclusion: The adaptive approach has considerable advantages and comparable efficacy to the linear method in terms of post-test score and self-reported knowledge and satisfaction of participants. Thus, this method of education may be as effective as the linear method for instruction in dental bleaching. The use of an adaptive approach is therefore recommended in educational curricula.

Background: The efficacy of electronic continuing education courses in comparison to lectured based methods requires further evaluation. This study aimed at comparing the effect of electronic (e-learning) and face-to-face conventional instruction on level of knowledge of general dentists on bleaching of discolored teeth. Methods: In this quasi-experimental controlled trial study in 2017 (1396) with post-test and control group design, firstly, a lecture-based continuing education courses at Shahid Beheshti University on discoloration of a single tooth was carried out for general dentists (as the control group, N = 35). Then, a continuing education online course with the same topic was done for the second group (N = 35). Convenience sampling was used to select participants of each group. Data were collected by a researcher-made questionnaire, which consisted of 2 parts (post-test with 10 questions and a satisfaction questionnaire with 10 questions). Content validity and test-retest reliability (r = 0.8) of both was determined. Data analysis was performed using the t-test and Pearson’s chi square test using the SPSS 23 software. The level of statistical significant was considered at P = 0.05. Results: The mean knowledge score after education was 7.02 (2.87) in e-learning and 6.77 (1.23) in the conventional group. The difference between the 2 groups was not significant (P = 0.63). Overall, 91.4% in the e-learning and 91.5% in the conventional group believed that the educational course obviated their occupational needs. Conclusions: E-learning was as effective as conventional instruction for bleaching of a single discolored tooth in terms of knowledge score (post-test score) and self-reported satisfaction and attitude of dentists.

Objectives This study evaluated the effect of lactic acid and acetic acid on the microhardness of a silorane-based composite compared to two methacrylate-based composite resins. Materials and Methods Thirty disc-shaped specimens each were fabricated of Filtek P90, Filtek Z250 and Filtek Z350XT. After measuring of Vickers microhardness, they were randomly divided into 3 subgroups (n = 10) and immersed in lactic acid, acetic acid or distilled water. Microhardness was measured after 48 hr and 7 day of immersion. Data were analyzed using repeated measures ANOVA (p < 0.05). The surfaces of two additional specimens were evaluated using a scanning electron microscope (SEM) before and after immersion. Results All groups showed a reduction in microhardness after 7 day of immersion (p < 0.001). At baseline and 7 day, the microhardness of Z250 was the greatest, followed by Z350 and P90 (p < 0.001). At 48 hr, the microhardness values of Z250 and Z350 were greater than P90 (p < 0.001 for both), but those of Z250 and Z350 were not significantly different (p = 0.095). Also, the effect of storage media on microhardness was not significant at baseline, but significant at 48 hr and after 7 day (p = 0.001 and p < 0.001, respectively). Lactic acid had the greatest effect. Conclusions The microhardness of composites decreased after 7 day of immersion. The microhardness of P90 was lower than that of other composites. Lactic acid caused a greater reduction in microhardness compared to other solutions.

The efficacy of methods like e-learning as a supplement to traditional face-to-face instruction needs to be evaluated in dental courses. This study aimed to assess the efficacy of posting case presentations on one of the educational websites of the virtual school of Tehran University of Medical Sciences called “SARMAD” to enhance the ability of senior dental students to diagnose tooth discolorations and offer treatment plans. This experimental study had a pre-test/post-test control group design and was conducted on 63 senior dental students. After filling out the primary questionnaire and obtaining a written informed consent, students participated in a pre-test and were then randomly divided into two groups of intervention and control. Fifteen case presentations were posted on the university website (SARMAD) during 6 weeks and discussed. Then, students participated in a post-test. Students’ perspectives and their satisfaction with the website were assessed by a questionnaire. For ethical purposes, the same program was also offered to the controls. The post-test score was significantly higher than the pre-test score in the intervention group (P

The aim of this study was to assess the effect of 30% hydrogen peroxide on the microleakage of class V cavities restored with either a silorane-based composite or two methacrylate-based composites.A total of 96 standard class V cavities (1.5 × 2 × 3 mm) were prepared on the buccal surface of sound extracted human premolars with both enamel and dentin margins and randomly assigned into three groups of Filtek P90 (group A) with its respective bonding (P90 system adhesive), Filtek Z250 (group B) and Filtek Z350XT (group C), both with Adper Prompt L-Pop bonding. The teeth were subjected to thermocycling (1000×, 5-55ºC) and half of them randomly underwent bleaching (30% hydrogen peroxide, 15 min, three times), while the remaining half (control) were not bleached. Dye penetration was measured following immersion in 2% basic fuchsin for 24 h. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests at 95% CI.No significant differences were found between the composites in the control groups in enamel (P=0.171) or dentin (P=0.094) margins. After bleaching, microleakage of Z250 (at the occlusal (P=0.696) or gingival (P=0.867) margins), Z350 (at the occlusal (P=0.323) margin) and P90 (at the occlusal (P=0.316) or gingival (P=0.281) margins) did not change significantly.No significant differences were noted between the bleached and control subgroups of Z250 and P90 in enamel or dentin margins. Microleakage of Z350 composite was reduced at the gingival margin compared to the control group, but no significant difference was observed at the occlusal margin. Microleakage of silorane-based composite in gingival margin was significantly more than two metacrylate-based composites.