Caspian Journal of Dental Research
Volume:12 Issue: 2, Sep 2023

Due to concerns about histological caries and recurrent caries after the use of sealants, adhesive systems containing fluoride and antibacterial agents have been proposed. The aim of this study was to evaluate the microleakage of sealants after the use of antibacterial chlorhexidine solution on etched enamel with and without the use of fifth- and sixth-generation adhesive systems.

In this experimental study, sixty sound human premolars were divided into 4 groups as follows:  Group A: Etching, fissure sealant; Group B: Etching, chlorhexidine solution (2 %), fissure sealant; Group C: Etching, chlorhexidine solution, single bond, fissure sealant; Group D: Etching, chlorhexidine solution, Clearfil SE Bond, fissure sealant. The samples were thermocycled for 500 cycles and immersed in basic fuchsine 0.5%. Then, the teeth were embedded in acrylic resin and cut buccolingually parallel to the long axis. Microleakage of the specimens was observed under ×40 magnification and graded from 0 to 3. Data were analysed using the Kruskal-Wallis and Mann-Whitney U tests. A value of p<0.05 was considered significant.

Sealant micro-leakage was statistically lower in group A (etching, fissure sealant) than in groups B, C and D, the groups with the chlorhexidine solution (P < 0.05).   There was no statistically significant difference between groups B, C and D.

The use of chlorhexidine solution on the etched enamel increases the sealant microleakage; with and without the application of the adhesive systems, Single Bond or Clearfil SE Bond. Therefre, it cannot be used as one of the steps in the application of the sealant to reduce the colonization of bacteria around the fissure sealant.

Dental implants are widely used to replace missing teeth. The crown-to-implant ratio is a determinant factor for the survival/success of dental implants. The aim of this study was to investigate the effect of diameter, length, and crown-to-implant ratio on the stress distribution around dental implants using the finite element analysis (FEA) method.

In this in vitro study, the cone-beam computed tomography (CBCT) of a patient with an edentulous mandible was used to create a three-dimensional model. The model was uploaded into the Mimics software and the contour model of the mandible was produced. The final file was uploaded into the ABAQUS software for FEA. The mandibular first molar was simulated and reconstructed using six models and in accordance with implant dimensions (diameter: 4.1 and 4.8mm; Length: 6,8,10mm) and axial forces of 200 N and angles of 0°, 15°, 30°, and 45°. The von Mises stress was used to determine the yielding of materials under multifaceted loading from the results of uniaxial tensile tests.

The maximum value of von Mises stress, in all six models was observed in the implant, crown, and cortical and cancellous bones, respectively (491.7, 303.5, 205.8,52 MPa). The highest stress value in all models was observed in the implant neck and the stress levels were decreased towards the apical implant. The stress value around the implant increased with increasing crown-to-implant ratio (69.2, 77.6, 92.9 model <1, 1>1 respectively).

The stress value around the implant increased with increasing crown-to-implant ratio and inclination angle and decreasing diameter and length.

The craniofacial anthropometric ratios are very useful in sciences such as dentistry, maxillofacial surgery, developmental studies and plastic surgery. The manual method of analyzing facial photographs requires a lot of time and precision. The aim of this study was to introduce an application tool that fully automates the analysis of facial photographs and compare it with the manual method.

In this cross-sectional study, the database consisted of 395 profile photographs, 271 frontal photographs in smile and 346 frontal photographs at rest. A two-stage fully convolutional network architecture was used for landmark detection. Two methods of manual and automatic analysis were compared in the measurement of 8 variables, including buccal corridor space, ratio of the height of the middle to the lower third of the face, total facial convexity angle, facial convexity angle, nasofacial angle, mentolabial angle, and nasofrontal angle. The agreement between the two methods was evaluated using the paired T-test and intraclass correlation coefficient (ICC). A value of p<0.05 was considered significant.

 For total facial convexity (P=0.005), nasofacial (P=0.001), and nasolabial (p=0.02) angles, the difference between the two methods was significant. However, no significant difference was found between the two methods for facial convexity, mentolabial, nasofrontal, buccal corridor space, and the ratio of the height of the middle to the lower third of the face no significant difference was observed between the two methods. The ICC for all variables was found to be greater than 0.69 except for the nasolabial angle. For most of the measured variables, the accuracy of the automatic method was similar to that of the manual method.

Machine learning has the potential to be used in clinical soft tissue analysis. It offers the ability to perform reliable and repeatable analyses on large image datasets.

Candida albicans [C. Albicans] is an opportunistic microorganism of the normal flora that can cause infection in the oral mucosa. Nitric oxide [NO] is a free radical produced by macrophages and is highly associated with antifungal activities. The aim of this study was to evaluate salivary nitric oxide levels in patients with and without Candida Albicans-associated denture stomatitis.

In this cross-sectional study, 40 edentulous patients using dentures were divided into two groups: patients with and without denture stomatitis [DS]. Before laboratory detection of candida, an oral medicine specialist clinically confirmed the presence of DS. Saliva samples were collected by spitting method, and the Griess method measured NO. Chi-square and Mann-Whitney tests were used for statistical analysis. The level of significance was considered 0.05.

The present study showed that the NO level was significantly higher in patients with DS than in patients without DS (P-value=0.002). In this study, the mean NO level in patients with DS was 166.5485±43.538 μM, while that was 118.0585±47.617 μM for patients without DS.

NO concentration in patients’ saliva can be associated with C. Albicans infection in the oral cavity. In the presence of Candida, the level of NO increases, and it seems that this increase is a kind of defense response to the presence of fungal infections.

Some studies have indicated that toothache is the primary reason for dental visits. The present study was conducted to assess the initial responses of Iranian individuals to toothaches.

The study included individuals referred to six dental clinics in Qazvin with severe pain. Then, they were asked about their initial reaction to pain. Seeking professional medical attention was considered a correct decision. The significance level was set at ≤ 0.05.

503 participants with a mean age of 31 (±7.5) years, including 260 females and 243 males. The initial reaction after the onset of toothache were searching the Internet [n=168], followed by visiting a dentist [n=143]. A significant correlation was found between age, history of dental visits, and correct reaction (p=0.033).

The Internet and social media significantly influence individuals' decisions regarding pain management. A notable proportion of individuals prefer self-treatment over visiting a dentist following a severe toothache.

Calcifying odontogenic cyst (COC) is an odontogenic cyst with accumulation of ghost cells that has central and peripheral subsets. Here, we present an 11-year-old male patient with an intraoral swelling on the left posterior mandibular ridge interfering with eruption of the second molar. Histopathologic examination revealed a cystic lesion lined by ameloblast-like epithelium in the basal layer and accumulating ghost cells in the upper layers. The final diagnosis was peripheral COC, and there was no recurrence after 6 months. This case has shown that histologic examination is required for every simple case.

Multiple mucous retention cysts are relatively rare conditions, particularly on the lower lip. This case report presents a 60-year-old man with multiple swelling structures located in the right and left buccal mucosa, and lower labial mucosa. A biopsy was done, and a histologic assessment confirmed dilation of minor salivary ducts and cystic formation. Several factors may interfere with the creation of this uncommon phenomenon, such as alteration in salivary secretion, and congenital or acquired weakness in the ductal structure. In addition, it is suggested that ductal narrowing may be due to the long-term application of some mouthwash containing hydrogen peroxide, deodorant also anti-plaque, and tartar-control toothpaste.