Journal of dentistry (Shiraz, Iran)最新文献

Background: Endodontic therapy plays a pivotal role in dentistry, with effective removal of intracanal medications crucial for successful treatment. The lingering presence of calcium hydroxide within dentinal walls can impede sealer adhesion and compromise treatment outcomes.

Purpose: This study aimed to compare the efficacy of various methods for removing calcium hydroxide from different regions of the root canal wall.

Materials and method: In this in vitro randomized trial study, 108 extracted teeth underwent canal cleaning and shaping using the Dentsply Protaper Gold rotary system. Subsequently, except for the negative control group, all teeth were filled with calcium hydroxide and divided into eight groups. These groups underwent different cleaning protocols involving Gentle Brush or Gentlefile #021 files or master apical file in combination with ethylene-diamine-tetra-acetic acid or sodium hypochlorite solutions. After tooth splitting, stereomicroscopic images were taken, and Digimizer software was utilized to calculate residual calcium levels in coronal, middle, and apical regions. Mann-Whitney test was used to check the effect of the cleaning method and type of washing solution among the methods employed. All the analyses were conducted using SPSS 22.

Results: The results indicated that the Gentle Brush method's superior efficacy in calcium hydroxide removal compared to other files, which was statistically significant (p Value <0.01). Similarly, the ethylene-diamine-tetra-acetic acid rinse solution proved more effective than sodium hypochlorite in clearing calcium hydroxide from the canal wall (p< 0.05).

Conclusion: The findings suggest that a Gentle Brush combined with an ethylene-diamine-tetra-acetic acid washing solution represents the most effective method for canal cleaning and calcium hydroxide removal. This study underscores the importance of employing efficient techniques to enhance treatment quality in endodontic practice.

Background: The accessory maxillary sinus ostium (AMO) is one of the anatomical variations in the maxillary sinus. The acquired or congenital nature of AMO has not been proven. In theory, mucus drained from the principal ostium may reenter the sinus through the accessory ostium and cause maxillary rhinosinusitis.

Purpose: The aim of the present study is to investigate the AMO frequency and its correlation with some anatomical and pathological variables in the area using cone-beam computed tomography (CBCT) images.

Materials and method: This was a descriptive-analytical cross-sectional study. CBCT images were obtained from 273 individuals and a total of 461 maxillary sinuses. The presence of AMOs and their relationship with age, sex, sinus mucosa condition, patency of the principal ostium, septal deviation, and sinus dimensions were measured.

Results: The AMO frequency was 35.6% and 14.63% of sinuses had more than one AMO. AMO was more common in men. There was a statistically significant relationship between AMO presence and abnormal mucosal status of maxillary sinus. The present study showed a statistically significant relationship between the presence of AMO and the anterior-posterior dimension of the sinus.

Conclusion: AMO occurred more frequently in the sinuses with abnormal mucosal status. However, when the abnormal sinus mucosa has reached the nasal fontanelle, it is not possible to check the presence of AMO by CBCT images.

Background: Head and neck cancers (HNCs) are among the top ten most common cancers globally. There is a clear geographical bias in the prevalence of HNCs. More than two-thirds of HNC cases worldwide occur in low- and middle-income countries. Due to the high prevalence of HNCs in Fars province.

Purpose: The purpose of this study was to assess the spatial pattern of HNC incidence rates by modeling both the effects of spatial dependence between neighboring regions and risk factors in a Bayesian Poisson model (BYM).

Materials and method: In this cross sectional study, from the Center of Cancer Registry in Fars province, data was collected from 1,821 patients diagnosed with HNC. The effects of spatial structure were modeled in a Bayesian spatiotemporal hierarchical model to determine the relative risk and trend of HNC incidence rates. The maps were created geographical variations of HNCs incidence across the 29 counties of the province with classical Standardized Incidence Rate (SIR), BYM model, and spatiotemporal model.

Results: The highest crude incidence rates were 0.55 and 0.16 cases per 1,000-person population for HNC and squamous cell carcinoma (SCC), respectively. Spatially, the highest relative risks for HNC and SCC were estimated at 1.36 and 1.34, respectively, in the county of Shiraz, the capital of Fars province. The lowest relative risks for HNC and SCC were estimated at 0.39 and 0.46 per 1,000 persons, respectively, in Gerash County in southern Fars. The findings showed an increasing trend in the HNC incidence rate and a decreasing trend in SCC incidence in this province.

Conclusion: Spatial analysis of HNCs revealed a high incidence rate in the northern and northeastern parts of Fars province, which may be attributed to the effects of lifestyle factors and certain pollutants in the region's cold air.

Pacinian neurofibroma is a rare variant of neurofibroma composed of structures resembling pacinian corpuscles at various stages of maturation. It is a rare neurogenic tumor which has been reported predominantly on hands, and feet, where pressure receptors are typically located. It usually presents as a solitary nodule and is not reported in associated with von Recklinghausen's disease or any other syndrome. The intraoral site is unusual. The purpose of this report is to present a rare case of intra-oral pacinian neurofibroma associated with neurofibromatosis type 1 and to describe its clinical and microscopic features contributing for the best knowledge about this rare entity.

Background: Maxillofacial trauma constitutes a major public health concern due to its potential for severe complications and substantial impact on quality of life.

Purpose: This study aimed to elucidate the factors influencing the occurrence of maxillofacial trauma in patients presenting with traumatic injuries at Peymaniyeh Hospital in Jahrom, Iran.

Materials and method: This cross-sectional study examined trauma patients at Peymaniyeh Hospital in Jahrom, Iran, from April 2022 to March 2023. A census approach included all trauma patients whose data were recorded in the National Trauma Registry of Iran. Data were collected using a tailored checklist that captured demographic and contextual variables along with injury mechanisms. Statistical analyses were performed using SPSS version 22.

Results: Of 924 trauma patients, 218 were diagnosed with maxillofacial trauma and 706 with non-maxillofacial trauma. The majority of the trauma patients were male (76.4%), and the distribution of age groups was not statistically different between the two types of injuries (p= 0.571). Univariate analysis revealed that substance (p= 0.007) and alcohol use (p< 0.001), road traffic accidents (RTAs) (p= 0.001), and representation of motorcyclists (p= 0.001) were significantly more prevalent in maxillofacial injury compared to non-maxillofacial injury category. Logistic regression analysis revealed that substance use (OR= 2.04, 95% CI 1.03-3.99, p= 0.040), alcohol consumption (OR= 2.89, 95% CI 1.37-6.09, p= 0.005), and experiencing RTAs (OR= 12.80, 95% CI 6.07-26.98, p< 0.001) and falling (OR= 3.69, 95% CI 1.68-8.11, p= 0.001) were significantly associated with the occurrence of maxillofacial injuries.

Conclusion: This study underscores the prominence of RTAs, particularly those involving motorcyclists, as a primary cause of maxillofacial injuries. The significant association between alcohol and substance use and the elevated risk of these injuries is evident. These findings highlight the need for targeted prevention strategies to promote safe driving practices, and implement public health policies aimed at mitigating alcohol and substance use disorder to reduce the incidence of such injuries.

Background: Micronutrients and trace elements have been linked to the development of head and neck squamous cell carcinoma (HNSCC). However, the role of these elements in the etiology of HNSCC remains unclear.

Purpose: This study was conducted to investigate the association between micronutrient and trace element levels and the risk of HNSCC.

Materials and method: In this case-control study, serum concentrations of iron, selenium, zinc, copper, and calcium were measured in 40 patients with HNSCC and compared to those of 37 healthy subjects. Statistical analysis was conducted using the Mann-Whitney test, Chi-square test, and independent t-test.

Results: The mean ages of the case and control groups were 62.80±13.029 and 57.92± 9.367, respectively, with 45% of HNSCC patients and 59.5% of control subjects being male (p= 0.205). Serum concentrations of calcium and copper were higher, and those of selenium, zinc, and iron lower in the case group than in the control group. Adjusted logistic regression showed only copper, calcium, and iron concentrations to be significantly different between the two groups (p= 0.003, p= 0.018, and p= 0.047, respectively).

Conclusion: The case group had lower levels of iron, zinc, and selenium, and higher levels of calcium and copper than the control group. Evaluating serum concentrations of these trace metals could be useful for further screening of individuals at high risk.

Background: Fixed orthodontic appliances, such as stainless steel and titanium brackets, might become exposed to magnetic resonance imaging (MRI) during treatment. However, the effects of MRI on microleakage and thermal changes in these brackets have not been thoroughly investigated. This study addresses these gaps to ensure safety and efficacy in patients undergoing orthodontic treatment while exposed to MRI.

Purpose: This study investigates and compares the effects of 1.5 tesla (T) MRI exposure on microleakage and temperature changes in stainless steel and titanium orthodontic brackets, evaluating their safety and bond integrity during orthodontic treatment.

Materials and method: In this in vitro study, forty non-carious, freshly extracted human maxillary premolars were randomly divided into stainless steel and titanium bracket groups (n=20). Each group was further subdivided into MRI-exposed (case) and non-exposed (control) subgroups. The case subgroups were subjected to a 1.5 T MRI scan for 20 minutes. Microleakage was evaluated using dye penetration under a stereomicroscope, and temperature changes were measured before and after MRI exposure. Statistical analysis included Kruskal-Wallis tests and paired t-tests. Significance was set at p Value <0.05.

Results: Microleakage at the enamel-adhesive interface was slightly higher than at the bracket-adhesive interface in all groups, but the differences were not statistically significant (p> 0.05). No significant differences in microleakage or temperature changes were observed between stainless steel and titanium brackets following MRI exposure (p> 0.05).

Conclusion: Exposure to a 1.5 T MRI magnetic field does not significantly affect microleakage or temperature changes in stainless steel or titanium brackets. These findings suggest that fixed orthodontic appliances do not need to be removed prior to MRI examinations, provided artifacts or image interference are not a concern.

Inflammatory myofibroblastic tumor (IMT), previously called an inflammatory pseudotumor, is an unusual, rare, benign, but aggressive tumor of soft tissue origin. It is histopathologically characterized by heterogeneous proliferation of myofibroblasts with admixture e of various inflammatory cells, including lymphocytes, plasma cells, histiocytes, and eosinophils. IMTs are rare in the head and neck region and are exceedingly rare in the jaws as central lesions; only nine cases have been reported in the literature. We report a case of intra-osseous IMT occurring in the posterior mandible of a 28-year-old lady with a detailed discussion of treatment, histopathological, and immunohistochemical features.

Background: Root canal treatment is one of the most critical dental treatments that help to maintain teeth. However, the growth of microorganisms leads to treatment failure. Considering the widespread use of mineral trioxide aggregate (MTA) in endodontic treatment, in vitro comparison of antibacterial, antifungal and anti-adherence activities of new types of MTA materials is indispensable.

Purpose: This study aimed to investigate and compare the antibacterial, antifungal, and anti-adhesion properties of three types of MTA, including A.G.M MTA (Andishe Gostar Masud, Tehran, Iran), Ortho MTA (BioMTA, South Korea), and Ultradent™ MTA Flow (Ultradent MTA Flow, USA).

Materials and method: In this laboratory study, the antibacterial activity of three MTA substances against the strain of Enterococcus faecalis (E. faecalis) was carried out by the modified direct contact test (MDCT) method in 1, 3, 7, and 14 days. Antifungal activity of MTA against Candida albicans (C. albicans) was performed using a tube-dilution test in 1, 24, and 72 hours. The antibiofilm property of three MTA substances against E. faecalis strain was determined using the crystal violet staining method and measurement by ELISA.

Results: Ortho MTA, A.G.M MTA, and MTA Flow showed intense antibacterial activity. The difference in the antibacterial effect of the three types of MTA was not statistically significant in all periods (p Value> 0.05). In the investigation of antifungal properties after 72 hours, all three types of MTA had antifungal properties (p< 0.050). Comparing the anti-adhesion properties of three MTA substances on E. faecalis, it is not significant (p< 0.05).

Conclusion: A.G.M MTA showed the highest antibacterial activity, and Ultradent MTA Flow and Ortho MTA showed stronger antifungal activity than A.G.M MTA. The highest anti-bacterial property was related to A.G.M MTA.

Background: The adoption of three-dimensional (3D) printing in dentistry for prosthetic workflows is increasing. A crucial step in the indirect fabrication of laminate veneers involves creating accurate master casts from digital impressions. However, there is limited information available regarding the accuracy of dental 3D printers in fabricating these master casts when different tooth preparation designs for laminate veneers are employed.

Purpose: This study aimed to assess and compare the accuracy (trueness and precision) of dental 3D printers in fabricating master casts for laminate veneers featuring three different incisal edge preparation designs (butt-joint, window, and palatal extension).

Materials and method: This in vitro, experimental study was conducted on three dental models made of polyether ether ketone (PEEK) with central incisor and canine teeth with three incisal preparation designs of window, butt-joint, and palatal extension for fabrication of laminate veneers. The models were scanned by the same laboratory scanner, and the standard tessellation language (STL) files were printed by four printers: Prodent (material jetting [MJ]), Asiga (digital light processing [DLP]), Hunter (DLP), and Luminous (light-emitting diode [LED]), 30 times. A total of 120 printed models were scanned again, and their scan files in STL format were compared with the reference model file to assess the trueness and precision of the printers. Data were analyzed using paired and independent t-tests, one-way analysis of variance (ANOVA), and Tukey test (α= 0.05).

Results: Asiga printer showed significantly higher trueness and precision than other printers (p< 0.05). No significant difference was found among other printers in trueness or precision (p> 0.05). The precision of window preparation design was significantly lower than other preparation designs (p< 0.05). No significant difference was found among other preparation designs in precision (p> 0.05). The difference in trueness was not significant among the preparation designs (p> 0.05).

Conclusion: Asiga printer showed significantly higher trueness and precision than other tested printers for fabrication of laminate veneers. Also, window preparation of the incisal edge resulted in significantly lower precision than butt-joint and palatal extension designs.