مجله تحقیق در علوم دندانپزشکی
سال بیست و دوم شماره 3 (پیاپی 85، پاییز 1404)

Saliva plays an important role in oral and dental health by maintaining the pH balance, buffering capacity and proteins. Chemical plaque control methods, such as mouthwashes, act as supplements. Salt water alkalinizes saliva and acts as a supplement. Salt water acts as an astringent & along with baking soda are effective in reducing mouth acidity. The purpose of this study is the effect of washing with salt water or baking soda on the pH of saliva and plaque.

This study was conducted on 62 dental students with an average age of 25 years including 31 men & 31 women. They used mouthwash for two weeks. 2 ml of saliva and some plaque attached to the distal surface of tooth # 6 on the right side of the lower jaw were collected. The pH of saliva and plaque in each group was measured using a pH measuring device manufactured by Teb Azma company in Iran before and after washing.SPSS software and Two Way ANOVA statistical test were used for statistical analysis.

Both sodium chloride and sodium bicarbonate mouthwashes increase the pH of saliva and plaque. Based on the results of the 2-Way Repeated Measure ANOVA test, the increase in pH of saliva and plaque after using sodium bicarbonate mouthwash is more than the increase in pH of saliva and plaque after using sodium chloride mouthwash (p-value<0. 001)

The increase in pH of saliva and plaque after using sodium bicarbonate mouthwash is more than the increase in pH of saliva and plaque after using sodium chloride mouthwash

This study evaluated the effects of pomegranate peel extract (PPE) and green tea extract (GTE) on the shear bond strength (SBS) of microhybrid composite to bleached enamel using universal bonding.

Forty-four intact maxillary premolars were divided into four groups:Group A (Control): Unbleached, restored with composite.Group B: Bleached with 35% hydrogen peroxide (Whiteness HP) and immediately restored.Group C: Bleached, treated with 5% GTE solution, then restored.     Group D: Bleached, treated with 5% PPE solution, then restored.
All specimens underwent phosphoric acid etching (Morvabon %, 15s), adhesive application (G-Premio Bond), and composite placement (3M Filtek Z250). SBS was tested using a Zwick universal testing machine. Failure modes were analyzed under 40× magnification.

No significant difference in SBS was observed among Groups A, C, and D (P > 0.99). All three groups exhibited significantly higher SBS than Group B (P < 0.001).

Post-bleaching application of 5% PPE or 5% GTE may mitigate the adverse effects of bleaching on composite bond strength to enamel

Candidiasis is a common fungal disease in the oral cavity. Recently, due to drug resistance and known side effects of medications, there has been an increasing tendency toward the use of medicinal plants. This study aimed to evaluate antifungal effect of aqueous and alcoholic extracts of banana pulp and banana peel (Musa AAA group, Cavendish subgroup) on standard Candida Albicans.

In this in vitro study, aqueous and alcoholic extracts of banana pulp and peel (Cavendish banana) were prepared at concentrations of 5, 2.5, 1.25, 0.62, and 0.31 mg/ml (n=32). The antifungal effects of the extracts were assessed using the disc diffusion method on agar. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the extracts were determined in comparison with nystatin. For analyzing data SPSS software version 26 and repeated measures ANOVA test was used.

The highest mean diameter of the inhibition zone in all groups belonged to nystatin, concentrations of 5 mg/ml, 2.5 mg/ml, 1.25 mg/ml, 0.62 mg/ml, and 0.31 mg/ml, respectively. There was no significant difference in the mean inhibition zone diameters between banana peel extracts and banana pulp extracts (p=0.09). However, the mean inhibition zone diameters of alcoholic extracts were significantly higher than those of aqueous extracts (p<0.001). The mean inhibition zone diameters of all concentrations were significantly lower than that of nystatin (p<0.05).

Aqueous and alcoholic extracts of banana (Musa AAA group, Cavendish subgroup) inhibited the growth of Candida Albicans, although their efficacy was lower than that of nystatin.

Background&

Odontogenic cysts are relatively common in dentistry. Given that little research has been done on the hyalinization and its impact on the biological behavior of various odontogenic lesions, the aim of the present study was to compare the subepithelial hyalinization of odontogenic keratocysts (OKC), dentigerous cysts (DC), and unicystic ameloblastoma (UA).

In this descriptive-analytical cross-sectional study, 30 samples of OKC, 30 samples of dentigerous cyst and 30 samples of unicystic ameloblastoma were selected from the archives of Oral Pathology Department of Isfahan Dental School which were prepared by excisional biopsy. All hematoxylin-eosin stained slides were examined simultaneously by the student and two oral pathologists using a light microscope to determine the presence or absence of subepithelial hyalinization and its severity. Recurrence of lesions was determined by reviewing the records and contacting the patients. The data obtained were statistically analyzed by t-test, Chi-square, and Fisher's exact test.

The highest level of subepithelial hyalinization was observed in the odontogenic keratocyst (OKC) group. A significant difference was observed between the study groups based on the presence or absence of subepithelial hyalinization (P = 0.003). On the other hand, no significant difference was observed between the study groups based on the severity of subepithelial hyalinization. However, a significant relationship was found between recurrence and subepithelial hyalinization (P < 0.001).

Subepithelial hyalinization can probably be used to predict and explain differences in the clinical behavior of the lesions

 The study aimed to examine the relationship between obesity and the taste  threshold, emphasizing the potential consequences of altered taste perception on the change of eating habits and their harmful effects on obese people

The study was conducted descriptively-analytically on 72 people, including 36 obese people(BMI>30) and 36 people with normal weight(18.50.05).

Based on the results of this study, the taste threshold of salinity in obese people was significantly higher than in normal- weight people .There was no statsisttically significants difference in the perception of other tastes between study groups.

Controlling and preventing the transmission of infectious diseases during dental procedures is a crucial pillar of the healthcare system. The present study aims to determine infection prevention behaviors during dental procedures based on the Health Belief Model (HBM) among dental students at Arak University of Medical Sciences in the year 2024.

This cross-sectional and analytical study was conducted on all dental students after the basic sciences phase (120 student) at Arak University of Medical Sciences in 2024, using a census method. In this study, a questionnaire based on the HBM was used to collect data. Finally, the data were analyzed using SPSS16 and statistical tests such as independent t-tests, Pearson correlation coefficients, ANOVA, and regression analysis and significant level is 0.05 considered.

In the study, 59.2% were male, and the rest were female. The average scores of knowledge (p=0.04), susceptibility (p=0.01), severity (p=0.04),benefits (p=0.01), and perceived barriers (p=0.01) showed a significant difference between male and female students (p < 0.05), with higher scores observed among female students. Based on the regression model, the most predictive variables—having completed the infection control course, perceived benefits, and perceived self-efficacy—collectively explained 46% of the variance in infection prevention behaviors during dental procedures among students.

In order to prevent the transmission of infectious diseases among students, emphasizing the increase in the results of benefit  behaviors and empowering students in this regard through increa information, showing films, and also based on the structuring of the internal control unit lesson.

Public understanding of the risks and benefits associated with X-ray imaging techniques is often limited, leading to prevalent misconceptions. To address these knowledge gaps, it is essential to provide accurate and accessible information. This study aimed to evaluate the attitudes of patients attending the dental clinic regarding radiation protection methods before and after the implementation of an educational infographic poster, thereby assessing the efficacy of this educational intervention.

This interventional study aimed to evaluate the impact of an educational poster on patient attitudes toward radiation safety in a dental clinic at Tehran University of Medical Sciences. Initially, a structured questionnaire was distributed to 120 patients to gather baseline data. After displaying the educational poster, a second round of questionnaires was conducted to measure changes in patient attitudes. Statistical analyses were performed to compare the percentage of correct responses before and after the intervention and to assess the effects of demographic factors such as education level, age, and gender using regression analysis.

The mean percentage of correct responses (± standard deviation) among patients prior to viewing the infographic was 41.33 (±10.17), whereas the post-intervention mean increased to 44.60 (±9.33). Notably, the p-value indicated that improvements in attitudes towards X-ray safety were not statistically significant across age groups, female participants, or those with higher academic qualifications. However, a significant enhancement was observed among individuals with lower educational attainment (high school or below) and male participants. The educational poster exhibited the greatest influence on males with lower educational backgrounds, while its impact was comparatively minimal among academically educated females.

The findings suggest that overall attitudes towards X-ray protection are suboptimal; nonetheless, the educational intervention has yielded a modest improvement in knowledge levels.

The appearance of teeth plays a key role in human social interactions. Tooth discoloration is one of the most frequent causes for patients to visit the dentist. Tooth discoloration is usually aesthetically unpleasant for patients and has a negative psychological effect on them. Orthodontic treatment, despite its well-known benefits, is a risk factor for tooth discoloration, ranging from imperceptible changes and loss of transparency to white and brown spot lesions. The current review study investigates the etiology of tooth discoloration after fixed orthodontic treatment and also describes its different treatment options.

In this review study, articles published in reputable databases, including PubMed/Medline, Scopus, and Web of Science, were reviewed without time limits until 2024. The articles were searched using the keywords Teeth discoloration and fixed orthodontics. Initially, 153 articles were reviewed, of which 31 were excluded due to similarity and 96 were excluded due to inconsistency with the topic. The abstracts of other articles were reviewed, and finally, 14 articles were included in the study.

Tooth discoloration after orthodontic treatment is multifactorial, and various etiological factors can directly or indirectly contribute to its development. The debonding process, type of adhesive system, finishing and polishing techniques, and type of brackets used are all factors that contribute to discoloration. Dentists must first diagnose the cause of the discoloration, educate the patient about its cause, and adopt appropriate management techniques.

Dental caries is the most prevalent chronic disease worldwide, requiring early diagnosis to prevent invasive treatments. Traditional detection methods have limitations, particularly in detecting early lesions. The aim of this study is to review the advances and challenges of artificial intelligence applications in dental caries detection.

A narrative review of articles published between 2015-2025 was conducted using established scientific databases including PubMed, Scopus, Science Direct, IEEE Xplore, Web of Science, and Google Scholar. Study quality was assessed using the QUADAS-2 tool, and data were analyzed based on artificial intelligence methods, imaging modalities, and performance metrics.

Convolutional Neural Networks (CNNs) and their derivatives such as U-Net, Mask R-CNN, and DenseNet are the most widely used algorithms in caries detection. The diagnostic accuracy of these systems was comparable to or better than dental specialists in many cases, particularly for early lesion detection. Artificial intelligence performance across different dental imaging modalities ranged from 71% to 99.2%.

Artificial intelligence demonstrates significant potential for revolutionizing dental caries detection, particularly in identifying early lesions that are crucial for non-invasive preventive interventions. The optimal approach is "assistive artificial intelligence" that serves as a complement to human clinical judgment rather than a replacement. Main challenges include dataset limitations, lack of standardization in methods and reporting, clinical workflow integration problems, need for transparency and explainability, and ethical-legal concerns. Future directions include developing larger and more diverse datasets, multimodal approaches, improving model explanation methods, conducting longitudinal clinical studies, and developing appropriate standards.