Dental Research Journal
Volume:20 Issue: 7, Jul 2023

Oral squamous cell carcinoma (SCC) is one of the most common malignancies in oral cavity. Hence, presenting methods for early diagnosis and find the etiologic factors of oral SCC are important. Saliva analysis can be used to discover various conditions because of its noninvasive methods. Copper as a useful metal has been used by men since ancient times. The level of copper increases when the cancerous changes occur in addition to biopsy, an alternative method for examining oral lesions is exfoliative cytology. The primary objective of this study was to determine the salivary copper level and cytomorphologic changes of oral mucosa among three study groups.

This cross‑sectional study included 15 individuals with oral SCC, 15 workers exposed to copper, and 15 healthy individuals. Saliva samples were collected and analyzed by atomic absorption spectrophotometer. The exfoliative smears were prepared by brush biopsy and stained by Papanicolaou and argyrophilic nucleolar organizer region (AgNOR) staining methods. Data analysis using one‑way ANOVA and Kruskal–Wallis test. P < 0.05 was considered significant.

There was a significant difference in mean salivary copper (P = 0.008), cytomorphology of oral mucosa, and AgNOR among the three groups (P < 0.001).

The results suggested that occupational exposure to copper increases the salivary levels of this element and causes changes in mucosal cells. Since this increase was very high and evidence of nuclear activity was seen in this group and in oral SCC patients, exposure to copper should be considered an important risk factor for oral mucosal changes.

This study evaluated the interface between fresh eugenol/bioceramic sealer‑conditioned coronal dentin and high‑viscous glass‑ionomer cement (HVGIC), treated with various dentin conditioners (saline, 10% polyacrylic acid, and 37% phosphoric acid).

Standard endodontic access preparation and instrumentation were done in 21 freshly extracted mandibular molar teeth in this in vitro study. Teeth were divided into two interventional groups (n = 9/group), based on the type of sealer (zinc oxide eugenol [ZOE]/ bioceramic [BioRoot RCS] sealer) used for obturation. Samples were further subdivided based on the type of dentin‑conditioning procedures performed (saline/10% polyacrylic acid/37% phosphoric acid). Post dentin conditioning, the access cavity was sealed with HVGIC. Later, material‑dentin interfacial analysis and elemental analysis were done using scanning electron microscopy (SEM) and energy‑dispersive X‑ray spectroscopy.

The interfacial SEM images of HVGIC layered over B‑RCS/ZOE sealer‑conditioned dentin, treated with saline, showed predominantly adhesive debonding failures, whereas cohesive debonding was observed with polyacrylic and phosphoric acid. In the elemental analysis, the intensity of zirconium (depicting the residue of B‑RCS)/zinc (depicting ZOE sealer) was very high on the dentin side treated with saline, in comparison to the dentin treated with polyacrylic and phosphoric acid. Furthermore, the intensity of elements from HVGIC was low on the dentin side of the groups with saline, whereas these elements showed maximum penetration into the dentin when treated with phosphoric acid.

Conditioning of the endodontic access cavity using 37% phosphoric acid immediately postobturation resulted in higher penetration of HVGIC into the dentin, in comparison to the other dentin conditioners.

Fracture is the most common reason for the failure of provisional restorations. This study aimed to assess the effects of the fabrication method (conventional, computer‑aided design/ computer‑aided manufacturing [CAD/CAM] milling, three‑dimensional [3D] printing) and material type on the fracture strength of provisional restorations.

In this in vitro study, 60 provisional restorations were made through the conventional (Tempron and Master Dent), CAD/CAM milling (Ceramill and breCAM.HIPC) and 3D Printing (3D Max Temp) methods based on a scanned master model. The provisional restorations were designed by the CAD unit and fabricated with milling or 3D printing. Then, an index was made based on the CAD/CAM milling specimen and used for fabricating manual provisional restorations. To assess the fracture resistance, a standard force was applied by a universal testing machine until the fracture occurred. One‑way ANOVA and Tukey’s test were used to compare the groups (α = 0.05).

The mean fracture strength was significantly different among the five groups (P < 0.001), being significantly higher in the breCAM.HIPC group (P < 0.001), followed by the Tempron group (P < 0.05). However, the three other groups were not significantly different (P < 0.05).

Despite the statistical superiority of some bis‑acrylics over methacrylate resins, the results are material specific rather than category specific. Besides, the material type and properties might be more determined than the manufacturing method.

The objective of the study is to compare stress distribution in a tooth restored with everstick post and sharonlay by means of three‑dimensional finite element analysis (3D‑FEA).

An experimental original study was carried out in which two 3D‑FEA models were constructed: (1) tooth restored with everstick post and metal ceramic crown and (2) tooth restored with sharonlay. The material properties were assigned and a force of 100N, 200N, 300N, and 400N was applied to the centric stop of the occlusal surface in centric occlusion at a 45° inclination in a linguolabial direction to the long axis of the tooth. Analysis was run and the stress distribution pattern was studied. As all stress distribution analysis was performed with the Ansys 11.0 software (Inventor AutoCAD 2010; Autodesk) program, the significance of P value or tests for statistical analysis was considered.

Sharonlay showed more total deformation, larger stress, and strain concentration than that of everstick post.

Tooth restored with sharonlay showed greater chances of deformation than everstick post. It also showed maximum strain concentration near the apical portion of the remaining tooth structure and more stress in the cervical third of the postsystem than everstick post.

Radiotherapy is a common treatment for head‑and‑neck malignancies and causes complications such as oral candidiasis and the change of oral Candida species from albicans to nonalbicans. Voriconazole has acceptable antifungal effect. The aim of this study was to determine and compare the antifungal effect of nystatin with voriconazole on these species.

The samples used in this in vitro study were identified by polymerase chain reaction‑restriction fragment length polymorphism from patients before and 2 weeks after head‑and‑neck radiotherapy in Seyed Al‑Shohada Hospital. The antifungal effect of nystatin and voriconazole was determined by microdilution method and measurement of the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration, and the results were analyzed by Mann–Whitney analysis.

The results showed that all species before and after radiotherapy showed 100% sensitivity to nystatin. Prior to radiotherapy, 57.1% of albicans species isolated were in the sensitive range (MIC ≤1) and 42.9% were in the dose‑dependent range (MIC = 2) to voriconazole. After radiotherapy, 58.3% of albicans species were in the sensitive range and 41.7% of these species were in the dose‑dependent range to voriconazole.

The results of the present study showed that before radiotherapy, all species were sensitive to nystatin, while a percentage of albicans and nonalbicans were resistant to voriconazole. In the 2nd week of radiotherapy similar to prior to radiotherapy, all species isolated from patients were sensitive to nystatin, while a percentage of albicans and nonalbicans were resistant to voriconazole.

Recently, the role of biochemical factors in the etiology of oral squamous cell carcinoma (OSCC) has attracted some attention. Serum levels of biochemical factors may change in cancer patients. This study aimed to assess the serum level of folate, Vitamin B12, homocysteine, iron, copper, and selenium in patients with OSCC.

This descriptive analytical study was conducted on 30 primary OSCC patients (15 males and 15 females) presenting to Imam Khomeini Cancer Institute, who had not yet undergone treatment. Blood samples were taken and serum levels of folate, Vitamin B12, homocysteine, iron, copper, and selenium were measured. Serum levels of micronutrients in patients with different tumor sizes were analyzed by one‑way ANOVA. Serum levels of micronutrients were compared among groups with and without metastasis and lymph node involvement using Student’s t‑test (P < 0.05).

Serum levels of B12, folic acid, homocysteine, copper, iron, and selenium were 232.5 ± 102.68, 8.66 ± 4.06, 18.87 ± 8.81, 96.0 ± 22.64, 55.27 ± 40.58, and 92.47 ± 18.83 ng/mL, respectively. Relatively similar values were measured in patients with different tumor sizes with and without lymph node involvement and presence or absence distant metastasis. However, the serum level of folic acid in OSCC patients without lymph node involvement was significantly higher than that in OSCC patients with lymph node involvement (P < 0.05).

Despite some variations, serum levels of micronutrients in OSCC patients were within the normal limits. Considering the variations in serum level of copper in OSCC patients, it may be used as a diagnostic marker. However, further studies are warranted in this respect.

Porcelain fracture or chipping is one of the limitations of all ceramic restorations. This study investigated the shear bond strength (SBS) of composite resins to lithium disilicate ceramics using universal bondings and different methods of surface preparation.

In this experimental study, 72 specimens of e.max computer‑aided design and computer‑aided manufacturing (CAD/CAM) ceramic blocks were divided into six groups of 12 according to surface treatment: Group I‑Hydrofluoric (HF) acid etching + All‑Bond Universal bonding (ABU), Group II‑Bur roughening (BR) + HF + ABU, Group III‑BR + HF + Bis‑Silane (Si) + ABU, Group IV‑Sandblasting (SB) + ABU, Group V‑SB + HF + ABU, Group VI‑SB + HF + Si + ABU. After bonding of composite resin to the prepared ceramic surface and storage of samples in distilled water for 24 h, SBS test was done using the universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed using the analysis of variance and Tukey’s post hoc test (α = 0.05).

The mean values of SBS in six studied groups were 6.65 ± 2.78 MPa, 8.56 ± 2.69 MPa, 8.49 ± 2.14 MPa, 3.13 ± 1.66 MPa, 7.94 ± 2.4 MPa, and 10.04 ± 2.47 MPa, respectively. The mean values of SBS were significantly different (P < 0.001). The highest value of SBS was observed in Group VI and the lowest in Group IV.

Ceramic sandblasting followed by HF etching, Bis Si, and ABU resulted in a higher SBS of composite resins to lithium disilicate ceramics.

This study compared postoperative pain after endodontic treatment of mandibular molars with asymptomatic irreversible pulpitis with the RaCe rotary system and the crown‑down versus the step‑down technique.

In this randomized clinical trial, 70 mandibular 1st and 2nd molars with asymptomatic irreversible pulpitis and normal periradicular state were randomly assigned to two groups for single‑visit endodontic treatment with RaCe rotary system and the crown‑down and the step‑down technique (n = 35). Postoperative pain was assessed at 6, 12, 24, 48, 72, and 168 h postoperatively, using a Visual Analog Scale. Data were analyzed using SPSS 17 by repeated measures ANOVA, Chi‑square test, independent sample t‑test, and lLeast sSignificant Ddifference test. P < 0.05 was considered statistically significant.

The two groups were not significantly different regarding the pain scores at any time point (P > 0.05). Within‑group comparisons showed a significant reduction in pain score over time, starting from 12 to 168 h, postoperatively (P < 0.05).

The crown‑down and step‑down techniques had no significant difference regarding postoperative pain after endodontic treatment of mandibular molars with asymptomatic irreversible pulpitis with the RaCe rotary system.

Patient demand for esthetic dental treatments is increasing, and among different techniques, tooth bleaching is a popular procedure for smile improvement. There is a controversy over the demineralizing effect of hydrogen peroxide (HP) containing bleaching agents on tooth enamel. The aim of this study was to evaluate the effect of HP and its combinations with hydroxyapatite (HA) and bioactive glass (BG) on enamel demineralization and tooth color changes.

Three groups of 20 teeth were used. Bleaching regimens included HP alone, HP + HA, and HP + BG. Bleaching was repeated at six periods of 15 min. Energy dispersive spectrometry was performed to evaluate calcium, phosphorus, sodium, magnesium, and fluoride content of superficial enamel before and after bleaching. Tooth color was evaluated by spectrophotometer before and after bleaching and ΔE values were calculated. Data were statistically analyzed using SPSS version 17.

Ca and P content was increased significantly in group HP + BG (P < 0.05). There was no significant difference in ΔE values between the three groups (P > 0.05).(p value = 0.34).

Addition of BG to HP can increase superficial enamel mineral content after bleaching and has no effect on tooth color changes in comparison to HP alone.

Ameloblastoma is the second most common benign odontogenic tumor with various histopathologic features. Except for the unicystic type of ameloblastoma, the different microscopic patterns of this tumor show no significant correlation with long‑term clinical behavior. During recent decades, additional challenging subtypes of ameloblastoma, including “Keratoameloblastoma” (KA), have been introduced in the literature. Here, we present a case of KA and discuss the important diagnostic microscopic features.