Journal of Clinical and Experimental Dentistry最新文献

Epithelioid hemangioendothelioma (EHE) is a rare neoplasm derived from the vascular endothelium. Although it can occur anywhere in the body, few cases have been described in the oral cavity. We report a 47-year-old woman presenting with a painful ulcerated lesion on the mandibular gingiva, suggestive of a traumatic decubitus ulcer. Histology and immunohistochemistry confirmed the diagnosis of epithelioid hemangioendothelioma. A literature review of EHE of mandibular gingiva was done. Pubmed were searched from 1975 through June 2024 using the following search terms: epithelioid hemangioentothelioma, vascular tumor, oral cavity and mandibular gingiva. Relevant manuscripts were selected and the results were used to update a narrative overview of the diagnosis and management of this entity. We found 38 cases of EHE in the oral cavity, of which 16 were located on the gingiva. Most of them were located on the mandibular gingiva as painless swelling, unlike our case. 70 % of the cases presenting in the mandibular gingiva had bone resorption on imaging. However, only half of those located in the maxillary gingiva had this bone resorption. Only 2 cases located in the mandibular gingiva presented recurrence and 1 of them debuted with nodal metastases after a 7-year follow-up. The clinical and histological diagnosis of EHE is complex and must be confirmed by immunohistochemistry. Upon diagnosing this entity, we should perform an excision with clear margins and conduct long-term follow-up due to the risk of local and distant recurrence. Key words:Epithelioid hemangioendothelioma, Gingival pathologies, Oral cavity, Mandibular Diseases, CD31, Immmunohistochemical markers, Vascular tumor.

Background: To compare measurements of tooth size and arch dimensions among those taken directly intraorally with those made on digital and 3D printed models produced by intraoral scanning.

Material and methods: Sixty-six participants were recruited. Intraoral tooth size and arch measurements were taken intraorally with a digital caliper. Digital impressions were taken with an iTero® intraoral scanner. The three-dimensional digital models were measured using a 3D diagnostics tool (OrthoCAD software). The same digital models were used to fabricate physical models using a resin 3D printer (Elegoo Saturn). The measurements were repeated on 3D printed models by using the digital caliper. The recorded parameters included mesiodistal tooth widths, transverse, and antero-posterior dimensions. All measurements were repeated to assess intra- and inter- examiner reliability. The validity of each measurement method was assessed by repeated measures ANOVA with post-hoc pairwise comparisons (p<0.5).

Results: The mean differences among three methods for all parameters were statistically significant (p<.05) but were considered to be clinically insignificant, except for the upper intercanine width. Direct intraoral measurements tend to be smaller than the digital and 3D printed models. The ICCs values indicated excellent intra- and inter-examiner reliability which demonstrates high reproducibility for all measurements on all model types.

Conclusions: Direct intraoral measurements tend to be smaller than the digital and 3D printed models. However, the accuracy of measurements made directly intraorally, and on digital and 3D models from intraoral scans is clinically acceptable, except for the upper intercanine width. Key words:Tooth measurements, Accuracy, Dental models, 3D printing, Digital model.

Background: In the search for alternatives to increase the bond strength of brackets, when necessary, this study proposes to apply the enamel deproteinization protocol to eliminate the proteins in the surface enamel to achieve better etching patterns and thereby increase bond strength. The aim of this study was to evaluate the effect of sodium hypochlorite as a deproteinizing agent on the bond strength of metal brackets.

Material and methods: Forty bovine teeth were randomly and equally divided into two groups. The experimental group (n=20) underwent a deproteinization treatment with sodium hypochlorite at 5.25% for 60 seconds prior to acid etching of the enamel with 37% phosphoric acid and bracket bonding with Transbond XTTM resin. The control group (n=20) underwent enamel etching with 37% phosphoric acid and bracket bonding with Transbond XTTM resin. Shear strength and the adhesive remnant index were evaluated and the Students t and Chi-square tests were used (P<0.05).

Results: The bond strength values of the control group (27.72±6.42 Mpa) were not significantly lower compared to the experimental group (29.21± 7.96 Mpa) (p=0.259). The adhesive remnant index showed a similar behavior in both groups, with the amount of adhesive remaining on the enamel being less than 50% in most samples of both the control and experimental group.

Conclusions: Deproteinization treatment of bovine tooth enamel with 5.25% sodium hypochlorite for 60 seconds prior to enamel acid etching does not improve the bond strength of a resin in orthodontic bracket bonding. Key words:Deproteinization, sodium hypochlorite, bracket bonding, orthodontics.

Background: Verruca vulgaris (VV), widely known as warts, is a common benign skin lesion, which is caused by human papilloma virus. In some cases, VV can be developed within the oral cavity. Surgical excision is considered as the most preferred treatment modality for both cutaneous and oral VV which could be challenge to deal with.

Case report: Herein, a short-term case of a 64-year-old male patient with a large oral VV, involving the lower and upper lips, and commissure was reported. The patient underwent a wide surgical excision, resulting in a significant lip defect. The modified Estlander flap technique was applied to treat the defect and restore lip function. At one year post operation, no signs of recurrence were recorded, and the Estlander flap technique displayed satisfactory outcomes.

Conclusions: Surgical management of oral VV involving lips may leaves large defect, which requires consideration in defect reconstruction. This case report shows that reconstruction of the defect with a modified estlander flap resulted in a good outcome, with satisfactory functionality for the patient. Key words:Estlander flap, verruca vulgaris, surgical excision.

Background: Inadequate polymerization of resins is a major cause of failure in dental restorations. This study aimed to evaluate the hypothesis that both polymerization distance and preheating of four nanohybrid resins significantly affect their degree of conversion (DC).

Material and methods: Four A2-colored nanohybrid resins were selected: Filtek Z250 XT (3M), Tetric N-Ceram (Ivoclar), Zafira (New Stetic), and Spectra Smart (Dentsply). These resins were chosen due to their varied compositions. Forty-eight discs (6 mm diameter, 2 mm thickness) were manufactured, with 24 discs preheated to 39°C. All discs were polymerized for 40 seconds at distances of 1 mm and 6 mm using the Bluephase N lamp (Ivoclar Vivadent), operating at 385-515 nm and 1200 mW/cm². The polymerized discs were stored in distilled water at 37°C for 24 hours, and the DC was measured using Fourier-transform infrared spectroscopy (FTIR). Statistical analysis was performed using one-way ANOVA and independent samples t-tests.

Results: No statistically significant differences in DC were observed between samples preheated to 39°C and those at room temperature (p> 0.05). Zafira exhibited the highest DC, significantly higher than Z250 XT in all groups (p< 0.005) and higher than Tetric N-Ceram on the surface (p< 0.05). Significant differences were also found between Zafira and Spectra Smart in specific conditions (p< 0.05). No significant differences in DC were found between polymerization distances of 1 mm and 6 mm. Uniform polymerization was achieved throughout the resin discs.

Conclusions: Preheating nanohybrid resins to 39°C had no statistically significant impact on their degree of conversion. Acceptable DC values were achieved using a high-intensity lamp for 40 seconds, even at a curing distance of 6 mm. Among the tested resins, Zafira demonstrated the highest DC under various conditions, significantly outperforming Z250 XT, Tetric N-Ceram, and Spectra Smart in specific comparisons. Key words:Nanohybrid composite, polymerization, degree of conversion.

Background: To compare the shear bond strength of brackets cemented to dental enamel according to the cementation techniques.

Material and methods: Experimental study. We used 90 premolars and placed them in printed polylactic acid (PLA) filament models to simulate the dental arch shape and to then cement brackets using the direct, indirect technique with Transbond™XT and indirect technique with Orthocem®. Then, we carried out a shear bond strength test using a universal testing machine, and we evaluated the enamel surface using the adhesive resin remaining index. Dunn's test was used for the inferential statistical analysis of shear bond strength, and Fisher's exact test was used for the adhesive resin remaining index.

Results: The shear bond strength of the brackets recorded mean values of 16.74±4.48Mpa, 15.93±6.49Mpa and 12.09±5.07Mpa in the direct, indirect technique with Transbond™XT and indirect technique with Orthocem® respectively. At an inferential level, a lower statistically significant difference was found in the indirect group with OrthoCem® in contrast to the other two groups. In the evaluation of resin remaining after detachment, the direct technique group registered 46.7% of teeth with more than half of resin remaining and the indirect technique groups with Transbond™XT and Orthocem® registered less than half of resin remaining with an incidence of 53.3% and 43.3% respectively. At an inferential level, a statistically significant difference between groups was evidenced.

Conclusions: The indirect cementation technique using Transbond™ XT is more recommended since it presents a higher shear bond strength than using Orthocem®. Key words:Orthodontics, Adhesion, orthodontic adhesives, shear bond strength.

Background: This study aimed to compare the efficacy of resin composite for establishing a proper proximal contact in comparison to digital work flow Zirconia for restoration of endodontically treated teeth (ETT).

Material and methods: Forty patients with posterior root canal treated teeth considering the inclusion and exclusion criteria were divided into two groups: half were restored by resin composite while the other received zirconia crown. Then, the proximal contact tightness (PCT) was measured via two methods: 1: VAS: the magnitude of felt PCT was recorded as a number between 0 to 10 (Visual Analogue Scale (VAS)). VAS direct and indirect as VAS-D, and VAS-I respectively. 2: Quantitative: using a custom-made force gage device to record the amount of force needed to pass a mounted dental floss through the proximal contact (Quantitative direct and indirect as Qn-D, and Qn-I respectively) those were compared with the PCT of natural teeth (NT). Data was compared with each other using Chi-square, Shapiro-Wilk, One Way ANOVA, Tukey Post Hoc, Linear regression, and Pearson tests (α= 0.05 in all tests).

Results: There were no significant difference between direct and in-direct groups regarding either sex of the patients (P= 0.10), type of teeth (P= 0.32), or jaw side (P= 0.36). The VAS-D and VAS-I showed similar results in pairwise comparison (P= 0.21). Moreover, both the Qn-D and Qn-I showed significantly higher PCT comparing to NT (P= 0.45 and 0.0.0001 respectively) while the Qn-D and Qn-I were not distinguishable statistically (P= 0.23). Furthermore, significant correlation was observed between VAS and quantitative methods for evaluation of PCT (Pearson P value= 0.005).

Conclusions: Both the direct and in-direct restorations lead to clinically acceptable PCT, whilst indirect restorations showed slightly better results which was not statistically noticeable. Key words:Composite resins, Zirconium oxide, Digital Technology.

One of the most contentious and extensively discussed topics in the field of dentistry when fabricating prosthetic restorations is the location and design of the finishing line in relation to the gingival tissues. Upon completion of the temporary crown and subsequent fabrication of the final restoration, two potential issues may arise: 1) the analog or digital impression may not accurately reflect the shape of the gingiva obtained with the temporary crown due to gingival collapse upon crown removal, even in the presence of retraction cords; and 2) the desired gingival shape may not have been achieved with the temporary crown. The objective of this article is to describe the stabilization of gingival tissues following twelve weeks of clinical observation. During this period, the provisional crown is recontoured twice in the apical-coronal direction with a four-week interval. This approach allows for the growth of sufficient gingival tissue in the horizontal direction at the point of the vestibular emergence profile, which will then stabilize once more following a slight recontouring of the final restoration, which will be performed in the clinic. The amount of gingival adaptation is not quantifiable in a numerical sense; rather, it is directly proportional to the amount of tissue that can be obtained with the new emergence profile of the temporary crown. The outcome is contingent upon the operator and there is no fixed quantity that can be achieved in every instance. In essence, there is no fixed numerical value that can be relied upon to lower the gingival parabola in the apical-coronal direction through the adaptation of tissues to the new shape of the temporary crown emergence profile. Key words:Vertical preparation, BOPT technique, tissue stabilization, final restoration.

Background: The present in vitro study evaluated and compared the microleakage and penetration depth of ACP containing pit and fissure sealant with flowable composite.

Material and methods: Sixty extracted non-carious premolars were categorized into four groups of 15 samples each. Sealant was applied after the Occlusal surfaces of the sample teeth were prophylactically treated with pumice slurry. Later, the teeth were thermocycled and immersed in methylene blue for a period of 24 hours. The samples were buccolingually sectioned and analysed under a stereomicroscope. Statistical analysis was carried out to compare the microleakage and depth of penetration.

Results: Flowable nanocomposite gave comparable results with that of the sealant in terms of microleakage. Nano-hybrid flowable composite performed better with respect to depth of penetration between tested materials with the difference being statistically significant.

Conclusions: Flowable nanocomposite can be considered as a promising substitute for sealing fissures and thus can be endorsed to caries susceptible pediatric patients. Key words:Depth of Penetration, Sealants, Microleakage.

Background: So far, different studies have endeavored to evaluate the position and dimensions of mental foramen and canal using cone-beam computed tomography (CBCT) images with various results. This study aimed to assess the anatomical variations of the mental foramen and canal utilizing CBCT images.

Material and methods: In this retrospective observational study, we investigated CBCT scans of 355 patients (710 terminal branches of mental canal and foramen) who were referred to a private dental and maxillofacial radiology center in Babol, during 2020-2022. We recorded different anatomical variations of mental foramina and canals on left (n=355) and right (n=355) mandibles.

Results: Most of the mental canals had a distal opening (n=334, 47.0%). The distance between the mental foramen and the lower mandibular border was greater on left mandible (13.92±3.73 mm) than on the right mandible (12.25±3.94 mm) (p<0.001). On left mandible, the vertical diameter of the mental foramen, as well as the distance between the mental foramen and the lower mandibular border, were significantly greater in men than in women. On right mandible, the distance between the mental foramen and the upper alveolar crest edge, as well as the distance between the mental foramen and the lower mandibular border, were significantly greater in men versus women. Finally, on right mandible, the vertical diameter of the mental foramen was significantly greater in subjects aged >45 years compared with those aged ≤45 (p=0.024).

Conclusions: There were notable variations in the morphological characteristics of the mental foramen and canal, which should be considered by clinicians. Key words:Mental foramen, mental canal, cone-beam computed tomography.