Journal of dentistry (Shiraz, Iran)最新文献

Spindle cell hemangioma (SCH), formerly called "spindle cell hemangioendothelioma", is a rare benign histological variant of hemangioma characterized by the presence of two contrast zones, the first zone exhibits large dilated cavernous space with slit-like vascular spaces may show clear endothelial vacuoles resembling fat cells. SCH is often considered as pseudosarcomatous entity; it imposes a diagnostic challenge for oral pathologists due to its resemblance with Kaposi sarcoma. A total of 13 cases of SCH have been reported in the head and neck region to date and only 6 cases have been reported inside the oral cavity. We present a rare case of SCH located on the hard palate, which imitated Kaposi's sarcoma on histopathological examination. The expressions of various markers including EGR, CD 31, and HHV 8 yielded the final diagnosis of SCH. The markers EGR and HHV 8 have never been used in intraoral SCH before to the best of our knowledge; hence, the present report highlights the use of immunohistochemistry for the diagnosis of SCH.

Background: Salivary gland tumors (SGTs) include benign and malignant tumors, such as pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC). Baculoviral inhibitors of apoptotic proteins (BIAPs) repeat-containing protein 6 (BIRC6), is an anti-apoptotic protein that plays an important role in cancers.

Purpose: We aimed to evaluate the expression of BIRC6 in SGTs and its correlation with the clinicopathological features.

Materials and method: In this cross-sectional study, 56 SGT tissue samples, including 15 cases of MEC, 20 cases of ACC, and 21 cases of PA, as well as nine cases of normal salivary gland tissues, were investigated for BIRC6 expression by immunohistochemical analysis.

Results: BIRC6 was found in 2.50%, 63%, 88%, and 63% of normal tissue, MEC, ACC, and PA, respectively. The mean total score of BIRC6 expression was 9.13; for ACC, MEC, PA, and normal tissue of the salivary gland were 10.25, 9.13, 9.00, and 3.00, respectively. The high expression of BIRC6 was detected in 29 cases of malignant and 15 cases of benign SGTs. The frequency of high or low expression was not different between the male and female patients (p= 0.833), patients aged below or above 65 years (p= 0.950), patients with different tumor sizes (p= 0.734), and metastasis status (p= 0.977).

Conclusion: The higher expression intensity and percentage of BIRC6 in malignant and benign SGTs suggests it as a potential marker to be used in future targeted therapy for SGTs.

Background: Despite the implants' remarkable success, mechanical failure of implant-abutment screws is a challenge for clinicians. Among the types of mechanical failures, abutment screw loosening is still frequently reported in the literature.

Purpose: The present study aimed to evaluate the effect of using lubricant on the detorque force (removal force) of locator/kerator abutment in overdenture patients after 6 months of clinical usage.

Materials and method: This pilot clinical study examined the detorque force of implants in 20 edentulous patients with two mandibular implants positioned between the mental foramen. The patients underwent the fabrication of a complete maxillary prosthesis and mandibular overdenture. Before loading attachments in the delivery session, healing abutments were removed, and implant interiors dried, randomly some fixtures received a tetracycline eye ointment 1% lubricant, while the others remained non-lubricated. Abutments were secured with prescribed torque according to implant system guidelines (20 N.cm). After 6 months, detorque forces for the abutment locators were measured using a torque meter. Descriptive statistics, mean comparison, and Pearson correlation were performed on the obtained data. A significant level of p Value<0.05 was considered in the present study.

Results: The mean detorque force was 13.4±1.94 in the non-lubricated group and 16.35± 1.24 in the lubricated group, which was significantly higher in the lubricated group (p< 0.001). Other results of the study include the non-significance of the difference in detorque force within male and female groups (p> 0.05), as well as the non-significance of Pearson's correlation between patients' age and detorque force (p> 0.05).

Conclusion: According to the results, the use of lubricant significantly increases the detorque force, and it is recommended to use tetracycline eye ointment as a lubricant in implant treatment processes.

Background: Calcium-enriched mixed (CEM) cement, though beneficial in endodontic applications, requires improvements in its physico-chemical properties to enhance clinical outcomes.

Purpose: This study was conceptualized to investigate the impact of incorporating nano-hydroxyapatite (nHAP) on the physico-chemical properties of CEM cement.

Materials and method: In this experimental study, nHAP powder at 5 and 10 wt% ratio was thoroughly mixed with CEM cement powder. Then they were mixed with a ratio of 1 g of powder to 0.33g of liquid and placed in special molds for each test. CEM cement without nHAP was used as a control sample. Samples were assessed for setting time, compressive strength, solubility, and pH.

Results: According to our results, the addition of 5% nHAP significantly increased the initial setting time (S1) and compressive strength after 24 hours, while the addition of 5% and 10% nHAP significantly enhanced the pH of the CEM cement.

Conclusion: Incorporation of 5% nHAP to CEM cement, although delayed S1 of this cement, but increased the pH level of CEM cement, which in turn could potentially improve the antimicrobial properties of CEM cement. Furthermore, the addition of 5% nHAP to CEM cement notably improved the compressive strength in the short term, which can be beneficial in withstanding the chewing forces after applying the cement in the oral environment. It is recommended to select an appropriate concentration of nHAP to optimize the properties of CEM cement based on the findings of this study.

Background: A few studies have examined the masking ability of the combined application of opaquer and resin composites on tooth discoloration.

Purpose: This study investigated the combined application of opaquer-composite to mask discolored backgrounds by utilizing two opaquers and resin composites.

Materials and method: In this in vitro research, we used two composite resins, Vitalescence (Ultradent) and Gradia Direct (GC), and two opaquers: Pink opaque (Cosmedent) and Creative Color A2 (Cosmedent). Seventy-two specimens were made as disks in 8 groups (n=9), with 1.0mm and 0.5mm thicknesses. One surface of each disk was coated by one of the opaquers and cured. The 4mm-thick composite disks from both composite brands were also made as a reference, representing the inherent color of the material. Then, the composite disks from the opaquer-coated surface were placed on a C4 porcelain disk as a background to simulate a discolored tooth. Color measurement for all specimens was performed using a spectrophotometer device. The color difference of each test group and 4 mm thick disks of the same composite were measured using the formula CIELAB (ΔE * ab). Statistical analysis was performed by using ANOVA and Tukey's Post hoc tests.

Results: Statistically significant differences were observed between the eight groups (p= 0.001). The thickness, composites, and opaquer variants significantly affected the ΔE*. The samples with 1mm thickness, the Vitalescence composite, and the Creative Color opaquer A2, had significantly lower ΔE* than the 0.5mm samples, the Gradia composite, and the Pink opaquer, respectively. The number of samples with desirable ΔE was significantly higher in the Vitalescence composite group than in the Gradia composite, and the Creative Color A2 opaquer had significantly more desirable ΔE than the Pink opaquer.

Conclusion: Most results that achieved acceptable masking ability were obtained with combinations of Creative Color opaquer A2+ Vitalescence / Gradia composite in 0.5 or 1mm thicknesses.

Background: Precise knowledge about the characteristics of individuals who snore but do not have obstructive sleep apnea (OSA) is essential yet remains limited in the literature.

Purpose: This study aimed to evaluate BMI (body mass index), upper airway dimensions, hyoid bone position, and their relationship in non-OSA snoring adults using cone-beam computed tomography.

Materials and method: In this retrospective cross-sectional study, cone beam computed tomography (CBCT) records of 100 patients were analyzed. Patients were snoring non-OSA individuals, diagnosed through a thorough examination and negative polysomnography results. CBCT scans were executed in the standard position as per the specified protocol of the Sleep Center. Upper airway was divided into four parts (nasopharynx, velopharynx, oropharynx, and hypopharynx), and anteroposterior (AP) and transverse (T) dimensions within the minimal cross-sectional area of each respective region were evaluated. BMI, upper airway dimension, and hyoid bone were analyzed using Pearson and Spearman's correlation tests.

Results:  The retrognathion-hyoid-4th cervical vertebra (RHV) angle representative of the hyoid position was significantly greater in females (p Value=0.000). It also statistically decreased significantly in snorers aged 36-50 and 51-65, p= 0.006 and 0.012, respectively. Snorers had above-average BMI in all age groups and both genders. The AP-hypopharynx significantly correlated with BMI (p= 0.022).

Conclusion:  The hyoid position was gender-dependent, with a superior position in females. It was also age-dependent, with a more inferior position in snorers aged 36-65 compared to younger ages (20-35). The AP-velopharynx is a constriction region in the airway of snorers. Snorers were overweight in all age groups and both genders. BMI had a significant correlation with the AP-hypopharynx.

Statement of the problem: One of the most important stages of root canal treatment is obturation for the root canal, an obturation with less voids will have fewer treatment complications in the future.

Purpose: This study was conducted to compare the quality of obturation of single-canal maxillary second premolars by the cold lateral compaction (CLC) versus continuous warm vertical condensation (CWVC) techniques using micro-CT.

Materials and method: In this experimental study, 36 extracted single-canal maxillary premolars were selected. The root canals were instrumented by Denco Blue rotary files. The teeth were randomly assigned to three groups (n=12) of control (no root filling), root canal obturation with CLC technique, and root canal obturation with CWVC technique. Next, they underwent micro-CT, and the mean volume and volume percentage (VP) of voids were calculated in the apical, middle, and coronal thirds of the root canals. Data were analyzed using one-way ANOVA, the Kruskal-Wallis, Mann-Whitney U, Bonferroni, Dunnett, Tukey, and independent t-tests (p Value<0.05).

Results: In the coronal third, no significant difference was found between the CLC and CWVC groups in the mean volume of voids (p= 0.273), the mean volume of filled space (p= 0.419), or the VP of voids (p= 0.605). The highest mean volume and VP of voids were recorded in the coronal part of the group CWVC (p> 0.05). The lowest mean volume and VP of voids was recorded in the apical third in CWVC group (p< 0.05).

Conclusion: None of the obturation techniques could provide a void-free root filling. Two techniques showed no significant difference regarding the mean volume and VP of voids in obturation of single-canal maxillary second premolars.

Statement of the problem: Tooth development is initiated by localized thickenings of the primary epithelial bands. Dentin sialophosphoprotein (DSPP) is the most abundant non-collagenous protein in the dentin matrix. DSPP's expression extends to multiple tissues, including dentin, cementum, and bone. However, the role of DSPP is not yet clear in the development of human tooth.

Purpose: The current study aimed to examine the DSPP expression profile during the development of human primary tooth structures with a sufficiently large sample size.

Materials and method: In this experimental study, a total of 33 samples of aborted human fetuses were divided into three age groups <16 weeks, <19 weeks and ≥19 weeks. Immunohistochemistry (IHC) was performed with Anti-DSPP rabbit polyclonal antibody. A two-way ANOVA analysis was conducted to examine the differences between the groups (p< 0.05).

Results: An increase in DSPP expression was observed with the progression of gestational weeks in different histological structures of developing human primary teeth.

Conclusion: An increase in the expression level of DSPP with the progression of gestational weeks may confirm that reciprocal interactions between the enamel organ (EO) and dental pulp cells contribute to tooth formation.