Frontiers in Dentistry最新文献

Oral schwannomas (OSs) are uncommon benign nerve sheath tumors accounting for 1% of all schwannomas and may arise from either soft tissue or bone. Cellular schwannoma is a rare histological variant of schwannoma which is characterized by increased cellularity. The most common intraoral site of occurrence is the tongue followed by the floor of the mouth and palate. Here, we are reporting a rare case of intraoral cellular schwannoma involving both facial and palatal gingiva of the right maxilla in a young Indian male patient.

Objectives: This study aimed to investigate the effect of common mouthwashes on the color change of a nanohybrid composite and its further stain susceptibility to Coke and coffee. Materials and Methods: One hundred and fifty composite discs were prepared and initial color values were measured using a spectrophotometer. The specimens were grouped based on the 24h exposure to common mouthwashes including Listerine, chlorhexidine, two types of fluoride mouthwashes (alcohol free and alcohol containing) as well as distilled water as control (N=30). The color change (ΔE1) values were calculated to show the amount of color change caused by mouthwashes. Subsequently, the specimens in each group were subdivided and immersed in the secondary colorant solution (coffee, Coke and, distilled water) for seven days. The total color change (ΔE total) values were obtained to show the stain susceptibility. Statistical analysis was conducted using ANOVA and Tukey's post hoc test. A P-value less than 0.05 was considered statistically significant. Results: The calculated ΔE1 of resin composite was significantly higher for all mouthwash groups than that of the control group; however, all were in the clinically acceptable range. Exposure to Listerine and distilled water caused more staining effects compared to other mouthwashes after immersion in secondary colorant solutions. Regardless of primary mouthwash type, coffee and distilled water caused the highest and the least total discolorations, respectively (P<0.001). Conclusion: All mouthwashes caused a clinically acceptable color change in resin composite; however, further stain susceptibility depended on the mouthwashes but was not higher than distilled water.

Objectives: This in-vitro study aimed to evaluate the physical properties of three resin-based root canal sealers, including BETA-RCS, AH26, and Adseal. Materials and Methods: Flowability, film-thickness, solubility, and radiopacity of BETA-RCS, AH26, and Adseal sealers were evaluated according to ISO 6876/2012 specifications. Three samples of each sealer were used to test each of the properties. Results: The results revealed that the flow rate (mm) of BETA-RCS, Adseal, and AH26 were 23.06±1.58, 22.5±4.23, and 21.85±1.71, respectively. Film-thickness values (µm) for BETA-RCS, Adseal, and AH26 sealers were 52.33±2.51, 18.66±0.57, and 52±2, respectively. No significant difference was observed regarding film-thickness between AH26 and BETA-RCS (P>0.05), while Adseal showed significantly lower film-thickness (P˂0.05). The highest and lowest solubility were related to BETA-RCS and Adseal, respectively. However, all sealers had acceptable solubility and radiopacity. Conclusion: The findings of the current study suggested that all three root canal sealers including BETA-RCS, AH26, and Adseal had similar properties based on ISO 6876 standard criteria. As such, they could be viable choices for facilitating effective root canal procedures. Further long-term clinical studies are warranted to assess their performance and success rates in actual endodontic cases.

Objectives: The aim of this in vitro study was to assess the quantity of nickel and chromium ions released from orthodontic wires when subjected to various beverage solutions and distilled water. Materials and Methods: Orthodontic appliances composed of five brackets, one band and 0.016-inch stainless steel and nickel titanium wires were immersed in Coke, tea, coffee and distilled water. The samples were incubated at 37°C for 1 hour, 6 hours, 24 hours, and one week. There was a total of 120 appliances divided into 24 groups (n=5 in each group). Atomic absorption spectroscopy was used to examine the amount of released ions. Two-way and one-way ANOVA followed by Tukey test were used for statistical analysis and P<0.05 was considered significant. Results: The release of nickel ions from both wires was highest in Coke and lowest in distilled water at all time points. Coffee and tea demonstrated values in-between these two limits. Similarly, chromium ion release from both wires was highest in Coke at all time-points compared to all other solutions (P<0.05). None of the other tested drinks showed significant differences in chromium ion release compared to distilled water. Conclusion: Restricting the intake of acidic drinks, particularly carbonated beverages like Coke, plays a critical role in safeguarding orthodontic wire components. Educating patients and providing dietary guidelines are essential for maximizing treatment effectiveness. Further research is required to investigate additional factors impacting ion release and devising methods to mitigate potential harm.

Objectives: Dental anxiety is a common phenomenon experienced by children in the dental setting. However, there is limited research on the effectiveness of cognitive-behavioral interventions in managing this anxiety. Therefore, the aim of this study was to evaluate the impact of a cognitive-behavioral psychologic intervention on dental anxiety in children. Materials and Methods: A total of thirty children, aged 7-10 years, underwent prophylaxis and fluoride therapy. The baseline anxiety levels of the children were determined using the Modified Child Dental Anxiety Scale (MCDAS). The intervention group (N=15) received two 30-minute sessions of cognitive-behavioral exercises. Additionally, a short film demonstrating a cooperative child undergoing pulpotomy was created and parents were instructed to show it to their children at home. During the treatment session, the exercises were reinforced at each step, and the MCDAS questionnaire was administered again. The children's behavior was also assessed using the Venham Clinical Cooperation Scale. Independent t-test, Mann-Whitney, chi-square, and Pearson's correlation coefficient were used for statistical analysis and P<0.05 was considered statistically significant. Results: Postoperatively, the MCDAS score in the intervention group was significantly lower compared to the control group. Notably, the intervention group demonstrated a downward trend in anxiety scores, while the control group showed an increase (P<0.001). Conclusion: Cognitive-behavioral interventions were found to be successful in decreasing dental anxiety in children undergoing pulpotomy. These interventions can be successfully implemented in clinical settings.

The adenomatoid odontogenic tumor (AOT) is a rare benign neoplasm that is typically treated through surgical enucleation and curettage. Any impacted tooth associated with the tumor are also extracted during the procedure. We present a case of AOT encompassing an impacted left maxillary central incisor in a 13-year-old male. The patient underwent routine treatment, but the tooth was orthodontically extruded using traction. Within two years, the incisor successfully attained its functional position in the arch, without any signs of recurrence. Preserving an impacted tooth associated with AOT is not common, and only a few cases have been reported in the literature. It is important to manage AOT conservatively and to save the associated tooth for both functional and aesthetic purposes. Long-term follow-up is crucial to monitor any potential recurrence. In summary, our case highlights the successful orthodontic management and preservation of an impacted tooth in a teenager with AOT.

Objectives: Due to their aesthetic appeal and translucent properties, clear thermoplastic retainers have become increasingly popular. However, ensuring their proper maintenance and cleaning is a significant challenge. It is essential to prevent any negative impact of cleaning solutions on the translucency and color consistency of retainers. Therefore, this study aimed to assess the effect of different cleaning solutions on the light transmission (translucency) rate of two distinct types of clear thermoplastic sheets. Materials and Methods: Two different clear thermoplastic sheets (Erkodent, Shodental), and five disinfectant solutions including chlorhexidine, Listerine, hydrogen peroxide, GUM whitening, and acid acetic served as the study materials and distilled water was used as control. The samples in each group (N=12) were immersed in the respective solutions for 15 minutes, twice a week and their light transmittance was measured using spectrophotometry after one and three months. Statistical analysis was conducted using two-way analysis of variance, with the significance level set at P<0.05 Results: Light transmittance decreased from baseline to 3 months for all study groups. After three months, the lowest translucency was related to retainers manufactured with Erkodent sheets, cleaned with GUM whitening (74.11±10.72%). The highest translucency after this period was found in retainers prepared with Shodental sheets immersed in Listerine mouthwash (88±1.55%). Only retainers treated with hydrogen peroxide showed significant difference between the thermoplastic sheets, which was higher in Erkodent (P<0.05). Conclusion: Our findings indicated that among the studied solutions, cleaning translucent retainers with Listerine mouthwash twice a week has the least effect on light transmission.

Objectives: The aim of this study was to assess how different soft drinks affect the deterioration of conventional and memory orthodontic elastomeric chains. Materials and Methods: We used 500 five-loop segments of elastomeric chains, which were divided into two equal groups of conventional and memory chains. The samples were kept in artificial saliva during the study period. Each group was further divided into 5 subgroups consisting of artificial saliva (controls), Coca-Cola®, non-alcoholic beer (ISTAK®), and carbonated and non-carbonated yoghurt-based drinks (Alis®). Treatment with the soft drinks consisted of immersion in the test liquids twice a day for 3 minutes each time. Force measurements were taken on days 1, 7, 14, 21, and 28. Data were analyzed using One- and three-way ANOVA tests, and independent t-test, with a significance level of 5%. Results: The mean initial force for the conventional and memory elastomeric chains was 3.34±0.112N and 2.49±0.209N, respectively. Conventional chains showed significantly greater degradation than memory chains (P<0.01). Soft drinks had a significant impact on force degradation for both types of chains at all time points (P<0.01). Coca-Cola® had the highest level of force degradation, while non-carbonated yoghurt-based drinks had the lowest (P<0.01). Conclusion: Based on the findings of this study, it is recommended that orthodontic patients choose non-carbonated yoghurt-based drinks during their treatment. Memory elastomeric chains may be more suitable for patients who consume large amounts of carbonated soft drinks, due to their lower amount of force degradation compared to conventional chains.

Objectives: Nickel-titanium (NiTi) rotary files were introduced to optimize root canal instrumentation in endodontic treatment. However, despite the numerous advantages of NiTi instruments, they may unexpectedly break during clinical use, resulting in obstruction of the root canal system. This investigation aimed to assess the effect of cryotherapy on fracture resistance of Neoniti rotary files. Materials and Methods: This in vitro, study was conducted on 20 Neoniti rotary files with #35 tip size and 6% taper in two groups with and without cryogenic treatment (N=10). For cryogenic treatment, the files were immersed in liquid nitrogen at -196°C for 24 hours. Next, the Neoniti files in both groups were subjected to cyclic fatigue testing in a hand-piece operating at 500 rpm with 20 N/cm torque. The files were rotated until fracture and the fracture time as well as the number of cycles to fracture were recorded for each file. The two groups were compared by independent t-test at 0.05 level of significance. Results: The number of cycles to fracture was 235700±50649.22 in the control and 280600±22979.21 in the cryotherapy group. The mean fracture time was 471.40±101.29 and 561.20±45.958 seconds in the control and cryotherapy groups, respectively. Significant differences in both variables were noted between the two groups (P<0.05). Conclusion: Based on our findings, utilizing cryogenic treatment may enhance the fracture resistance of rotary instruments, making it a beneficial practice for dental clinicians to adopt. By using cryogenically treated rotary instruments, clinicians can potentially reduce the risk of file fracture during dental procedures.

Objectives: Age estimation is a crucial aspect of forensic odontology, and the Tooth Coronal Index (TCI) has been widely used for forensic purposes in determining age. The aim of this research was to evaluate the effectiveness of TCI in age estimation. Materials and Methods: A retrospective study was conducted, and TCI was calculated for the mandibular first premolar in 700 digital panoramic radiographs. Age was divided into five groups: 20-30 years, 31-40 years, 41-50 years, 51-60 years, and >61 years. Bivariate correlation was used to establish the relationship between TCI and age. Linear regression was calculated for the different age groups and genders. Inter-observer reliability and agreement were assessed using one-way ANOVA. P-values less than 0.05 were considered statistically significant. Results: Comparison of the mean difference from actual age showed underestimation in males aged 20-30 years and overestimation in males over 60 years of age. The least difference between actual and calculated age was found in females aged 31-40 years. Inter-age comparison using ANOVA for females demonstrated a statistically highly significant difference from actual age in all age groups (P<0.01), with the highest mean in females aged 51-60 years and the lowest in females aged 31-40 years. Inter-group comparison of mean TCI revealed statistically non-significant differences in males and statistically highly significant differences in females (P<0.01). Conclusion: Age estimation using TCI on mandibular first premolars can be recommended as an easy, non-invasive, and less time-consuming method. This study suggests that regression formulas were more accurate for males aged 31-40 years.