Avicenna Journal of Dental Research
Volume:16 Issue: 4, Dec 2024

 Clinical identification of the inferior alveolar canal (IAC) is crucial before performing surgical interventions such as mandibular third molar extraction or jaw fixation to preserve the integrity of the IAC. This study evaluated the visibility of IAC borders using panoramic radiography (conventional and CBCT reformatted) and cross-sectional CBCT images.

 The conventional panoramic (CP) and CBCT images of 328 patients were evaluated, and the visibility of the IAC was assessed by three examiners across four equal 1 cm-wide regions, from anterior to posterior (Areas 1 to 4). For CBCT, reformatted panoramic (CRP) views were generated using curved multiplanar reformatting at the mandibular mid-root level within the software. Four cross-sectional images were obtained for each region. Visibility was rated as visible (score=1) or non-visible (score=0) across the three imaging modalities. Statistical significance was set at P value<0.05.

 Across all three radiographic modalities, the inferior border of the IAC was more consistently visible than the superior border. The highest visibility of the inferior border was observed in Area 4, with visibility rates of 92.1% for cross-sectional CBCT, 91.5% for CBCT-reformatted panoramic, and 92.4% for CP. The lowest visibility was found at the superior border in Area 2, with visibility rates of 86.9% for cross-sectional CBCT, 80.2% for CBCT-reformatted panoramic, and 67.4% for CP.

 Visualization of the IAC in the distal area of the mental foramen is more challenging than in other areas across all radiographic modalities. Given the superior visibility levels observed in CBCT images, especially for the superior border in Areas 1, 2, and 3, CBCT is recommended over CP radiography.

 The success of root canal therapy hinges on various factors, with biomechanical preparation standing out as a crucial step. Equally significant is the meticulous preservation of the canal’s natural shape, as any deviation from it can lead to complications such as canal aberrations or transportation. The aim of the study was to evaluate the canal transportation and canal centering ability of ProTaper Next (PTN), NeoNiTi, and R-Motion (RM) file systems using cone-beam computed tomography (CBCT).

 Thirty human mandibular molar roots with an angle of curvature between 10° and 20° were chosen into three groups of ten samples each from the pool of collected samples that met the inclusion and exclusion criteria, including PTN (group I), NeoNiTi (group II), and RM file systems (group III). To achieve reproducibility of pre- and post-operative CBCT scans and to ease instrumentation, the tooth was placed in a template created using silicon impression material. Using CBCT software, pre- and post-instrumentation pictures were obtained from the apex at three different levels (3 mm, 6 mm, and 9 mm). One-way analysis of variance and post hoc analysis were used to evaluate the amount of transportation and centering ability.

 RM demonstrated better canal centering ability than PTN and NeoNiTi at 3 mm and 6 mm, but there was no statistically significant difference in canal transportation between the three groups at levels of 3 mm, 6 mm, and 9 mm from the apex.

 PTN, NeoNiTi, and RM all exhibited similar behaviour under the study’s in-vitro conditions in terms of canal transportation and centering ability. However, the RM group outperformed the other systems in terms of both canal transportation and centering ability, with NeoNiTi and PTN systems coming in second and third, respectively.

 Pediatric dentists prefer restorative materials with a high bond strength and fewer clinical stages. Cention N can be used in the bulk technique. It can release fluoride ions, calcium, and hydroxide. This study compared the microleakage of two types of composite resins, namely, Cention N and Tetric N-Ceram bulk-fill composite resin, in class II restorations (box only) of deciduous teeth.

 In this experimental investigation, 50 class II restorations (box only) were prepared in extracted deciduous second molars. Then, the teeth were divided into two groups based on their restorative materials. The first and second groups were restored with Cention N and bulk-fill Tetric N-Ceram composite resins, respectively. The Tetric N bond adhesive was used before placing the restorative materials in both groups. The samples were cut and investigated under a stereomicroscope to determine microleakage after thermocycling and staining with silver nitrate. Two samples from each group were prepared for observation under an electron microscope. Then, the data were analyzed using the nonparametric Mann-Whitney test.

 The mean percentage of dye penetration into the gingival wall was not significantly different between the two groups under investigation.

 Using Cention N with adhesive yielded favorable results in terms of microleakage, and it is recommended for class II restorations in deciduous molars.

 Akt1, a serine/threonine kinase, plays a central role in cancer development and progression. Its overexpression correlates with aggressive phenotypes and poor prognosis in several types of cancers, such as oral squamous cell carcinoma (OSCC). Cinnamic acid derivatives (CADs) from natural sources exhibit anticancer properties, making them potential Akt1 inhibitors.

 The binding affinities of 19 CADs to the Akt1 catalytic cleft were evaluated using molecular docking simulations and then compared with the Akt1 inhibitor capivasertib. Interaction modes were analyzed to identify critical residues involved in ligand binding.

 Cynarin demonstrated the highest binding affinity (ΔGbinding =-13.46 kcal/mol, Ki=136.48 pM), forming three hydrogen bonds with Akt1. Rosmarinic acid with six hydrogen bonds also exhibited potent inhibition (ΔGbinding =-11.51 kcal/mol , Ki=3.67 nM). Both compounds represented superior binding compared to capivasertib.

 Cynarin and rosmarinic acid from natural sources showed promising inhibitory potential against Akt1, suggesting their therapeutic values as anticancer agents targeting the PI3K/Akt pathway in OSCC.

 Dentin hypersensitivity is a common issue among dental patients. There exist different treatments, including gels, solutions, toothpastes, and lasers. This study compared the effectiveness of Gluma, Colgate Sensitive Pro-Relief toothpaste, and 980 nm diode laser on dentinal tubule occlusion.

 In this experimental study, 40 premolar teeth without caries, fractures, restorations, or root canal treatments were chosen for analysis. The enamel of the samples was removed using a bur, and then the samples were prepared and divided into four groups. Three treatments were applied to three groups of teeth, and the fourth group was considered the control group. The number of occluded, semi-occluded, and open dentinal tubules in the samples was calculated using field emission scanning electron microscopy, and the results were reported as percentages. Statistical analyses were then performed using Kolmogorov-Smirnov, one-way analysis of variance (ANOVA), and Tamhane tests.

 The results showed that the number of occluded dentinal tubules was 90.3%±8.23, 74.4%±11.62, 67.60%±10.62, and 15.03%±3.39 in the laser, Gluma, toothpaste, and control groups, respectively. The differences between the three treatment groups and the control group were significant (P<0.05). All three different treatments significantly occluded dentinal tubules.

 Based on the findings, the 940 nm laser could effectively reduce dentin sensitivity.

 Significant advances in in-office bleaching treatments have been made by introducing some types of light sources. Halogen lights, LEDs, and diode lasers are the most popular devices used for in-office bleaching. There is a risk that bleaching-activating light sources might increase temperature and have side effects on the dental pulp. This study evaluated the effect of different light-activated bleaching gels on pulp chamber temperature.

 In this experimental study, 36 bovine incisor teeth were selected for investigation. The samples were divided into three groups, including Opalescence Xtra Boost PF bleaching gel with the 405 nm LED (group one), Opalescence Xtra Boost PF bleaching gel with 810 nm diode laser (group two), and Heydent bleaching gel with 810 nm diode laser (group three). Bleaching gels with a thickness of 1 mm were applied on teeth surfaces and activated according to the manufacturer’s instructions. The temperature change was recorded every second, and the results of the graph showing the peak temperature were plotted using SPSS software. One-way ANOVA was employed to determine the effect of bleaching type on temperature rise. In case of the presence of a significant difference, post-hoc Tukey’s test was utilized for pairwise comparison of the groups.

 The temperature rise considerably depends on the light sources. Group one (LED+bleaching gel Xtra boost) had the lowest temperature rise (1.87° C±0.15), while group two (diode laser+bleaching gel Xtra boost) had the highest temperature rise (3.55° C±0.50). There was a statistically noticeable difference in temperature rise among all groups (P<0.05).

 The light activation of in-office bleaching gels with the diode laser caused higher temperature changes as compared to LED. However, the detected temperature rise was not critical for pulpal health.

 One of the main stages of root treatment is mechanical preparation, which is performed using manual and rotary instruments with rotational and reciprocal movement. Complete debridement of the root canal in the preparation process is essential for a successful endodontic treatment. This study investigated the amount of apically extruded debris using WaveOne Gold, ProTaper Gold (PTG), and Neoniti A1 rotary files in mandibular premolars.

 As many as 60 mandibular premolar teeth were divided into three equal groups. Each group was prepared with a rotary file (WaveOne Gold, PTG, or Neoniti A1). Then, debris measurements were performed using the Montgomery method, and SPSS v-26 and robust and Brown-Forsythe tests were used for data analysis.

 The results showed that the highest and lowest amounts of extruded debris were in the PTG and WaveOne Gold files, respectively. There was a significant difference between the means of the three groups (P ˂ 0.05). In addition, to further evaluate the difference, the Games-Howell post hoc test was utilized, demonstrating a significant difference between the means of all three groups (P ˂ 0.001).

 The findings revealed that all systems extrude debris beyond the apical foramen. The WaveOne Gold system showed the lowest average value of apically extruded debris, followed by Neoniti A1, while ProTaper had the highest average value of apically extruded debris among the investigated systems. Thus, it is recommended that future studies investigate the effects of the properties and characteristics associated with the type of rotary files.

 Generalized gingival enlargement can arise from various causes. It may be hereditary, as observed in hereditary gingival fibromatosis, which occurs in association with syndromic conditions or results from the side effects of certain systemic medications such as phenytoin, cyclosporin, and nifedipine. This report discusses the condition of a 13-year-old girl who exhibited severe gingival overgrowth affecting both maxillary and mandibular arches, leading to substantial coverage of nearly all her teeth. The differential diagnosis included drug-induced enlargement and idiopathic gingival fibromatosis.

 A conventional flap surgery alongside osteoplasty was performed to address the excess gingival tissue. Due to the generalized nature of the enlargement, the surgery was conducted quadrant by quadrant.

 The postoperative recovery was smooth, and the patient showed significant improvements in appearance. Follow-up evaluations over two years post-surgery indicated that the gingival condition remained stable.

 Idiopathic gingival fibromatosis, although rare, is marked by significant gingival overgrowth. Surgical resection enhances aesthetics and improves functionality. While the recurrence of the condition is common, it may be managed or delayed through careful monitoring and scheduled follow-up appointments.