Dental Research Journal最新文献

Background: Tribulus terrestris (TT) extract has shown good antibacterial activity against some bacteria. However, there are limited data on its cariogenic properties. This in vitro study aimed to evaluate the antibacterial and antibiofilm activities of TT extract against Streptococcus mutans (S. mutans), Streptococcus sobrinus (S. sorbinus), and Lactobacillus acidophilus (L. acidophilus) as the important cariogenic bacteria.

Materials and methods: This study was designed in an experimental model (in vitro). Phytochemical tests were carried out to detect herbal compounds in the TT extract. Agar well diffusion was performed to compare the extract (500-62.5 mg/mL) with different concentrations of chlorhexidine (2-0.25 mg/mL). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the TT extract and chlorhexidine were also determined. The lowest concentration showing ≥50% inhibition of biofilm formation (MBIC₅₀) was determined using crystal violet assay. Further, the time-kill assay (Log of CFU/mL) was performed, and acid production (pH) was measured at 1 × MIC concentration in 2, 4, 8, 12, and 24 h. Data analysis conducted using SPSS software (v26, IBM) involved One-way analysis of variance, Tukey post hoc tests, and t-test to compare concentrations and groups. Significance level is set at 0.05.

Results: The TT extract mostly consisted of flavonoids. Its inhibition zones in the well diffusion test were statistically comparable with chlorhexidine in some concentrations (P > 0.05). The MIC of the TT extract was 15.625 mg/mL for all tested bacteria, whereas the MBC ranged from 31.25 to 62.5 mg/mL. Further, the MBIC₅₀ ranged from 7.8125 to 15.625 mg/mL for the extract. Time-kill assay showed that the bactericidal activity of the TT extract lasted for 8, 12, and 2 h for S. mutans, S. sobrinus, and L. acidophilus, respectively. The acid production decreased obviously after 8 h.

Conclusion: The TT extract showed good time-dependent antibacterial and antibiofilm activity, as well as acid production inhibition, against cariogenic bacteria in laboratory experiments.

Background: White lesions, also known as white spots, are the earliest signs of tooth decay. At this stage, noninvasive preventive treatments, such as fluoride application, can help to slow down or even reverse the progression of white lesions. For decades, fluoride has held the spotlight as the go-to agent in oral preventive care, demonstrating significant remineralizing power. Recent scientific literature reveals a growing interest in alternative products as natural substances that demonstrate potential remineralizing effects on tooth enamel. This in vitro study aimed to evaluate the potential remineralizing effect of calcium sodium phosphosilicate (CSP), ginger, and turmeric.

Materials and methods: This in vitro study was designed to evaluate the remineralizing effects of various materials on the enamel of extracted human teeth. The aim was to compare the effectiveness of these different substances in promoting enamel remineralization. Enamel blocks were prepared and were divided into seven experimental groups: CSP, fluoride toothpaste, nonfluoride toothpaste, turmeric, ginger, fluoride varnish, and distilled water. In this study, sample mineralization is assessed through the quantitative photo-induced fluorescence test before demineralization, after demineralization, and after remineralization. Statistical analysis of the data was conducted using a one-factor analysis of variance test. The significance level was set at P < 0.05.

Results: The best results were obtained by groups treated with turmeric (P < 0.0001), Enamelast fluoride varnish (P < 0.0001), and NovaMin (P < 0.01), as compared to other remineralizing treatments.

Conclusion: While fluoride has undeniably revolutionized oral preventive care, the exploration of alternative products as natural substances and innovative compounds in recent scientific literature signals a shift in focus toward safer and potentially more diverse options.

Background: This study aimed to assess the antibacterial effect of a nano-zinc oxide eugenol (nZOE) sealer alone and in combination with chitosan, propolis, and nanosilver on Enterococcus faecalis.

Materials and methods: In this in vitro, experimental study, nanosilver, chitosan, and propolis with 10wt%, 20wt%, and 60wt% concentrations, respectively, were added to nZOE sealer, and their antibacterial activity against E. faecalis was evaluated by agar diffusion and broth microdilution tests. The diameter of the growth inhibition zones was measured, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were calculated for all materials. Data were analyzed by t-test (alpha = 0.05).

Results: The addition of nanosilver, chitosan, and propolis to nZOE did not change the diameter of growth inhibition zone in agar diffusion test. Propolis and eugenol alone showed the lowest MIC and MBC. Chitosan alone showed the highest MIC and MBC. Furthermore, nZOE showed lower MBC than micro-ZOE (P = 0.000). All groups containing nZOE showed the lowest MIC and MBC values.

Conclusion: The addition of propolis to nZOE can enhance its antibacterial activity against E. faecalis in vitro.

Background: Titanium abutments are the gold standard of implant treatments. However, they may not create sufficient color matching to the natural teeth due to the gray color showing through under the ceramic crown. The present study aimed to determine the masking ability of computer-aided design and manufacturing () bleach shade ceramics in different thicknesses on titanium abutments.

Materials and methods: In this laboratory study, a total of 90 specimens of bleach shade ceramics Celtra Duo (CD), Vita Suprinity (VS), and zirconia Luxen were prepared in thicknesses of 1, 1.5, and 2 mm (n = 10). Background specimens of G-aenial composite in A3 color and titanium were used. The ceramic specimens were placed on titanium and composite backgrounds and L*a*b* color parameters and color difference (ΔE) were measured with the VITA Easyshade spectrophotometer. Data were analyzed using three-way and one-way analysis of variance tests. Pairwise comparisons of groups were also performed with Tukey's test. P <0.05 was considered statistically significant and ΔE <2.7 was considered clinically acceptable criteria.

Results: The effects of thickness, ceramic type, and their interaction effects on the ΔE were statistically significant (all three: P <0.001). The difference in ΔE values of bleach shade ceramics on titanium and composite backgrounds was estimated to be statistically significant in the thicknesses of 1 mm (P = 0.01), 1.5 mm (P < 0.001), and 2 mm (P = 0.001). Zirconia had a better performance for masking ability in thicknesses of 1.5 mm (P < 0.001) and 1 mm (P = 0.01), while VS ceramic showed the best masking ability in thicknesses of 2 mm (P = 0.001). The masking ability of ceramics was improved by increasing the thickness.

Conclusion: Except for VS ceramic in thickness of 1 mm, the rest of the bleach shade ceramics in all three thicknesses of 1, 1.5, and 2 mm have adequate ability to mask the titanium background and their use in line with the masking ability of titanium background has brought acceptable esthetic results.

Background: This study aimed to evaluate the effect of new computer-aided design/computer-aided manufacturing all-ceramic materials on the viability and adhesion properties of human gingival fibroblasts (HGFs).

Materials and methods: In this experimental study, the proliferation and adhesion potential of the cells were evaluated by seeding the HGF cells on rectangular samples (n = 18 for each group). The studied groups were tetragonal zirconia (TZr), cubic zirconia (CZr), lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), and hybrid ceramic (HyC) (n = 6 for each studied time). The cell viability (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay was conducted at determined times (24 h, 72 h, and 168 h) to evaluate the cell proliferation. Subsequently, the cultured cells were processed for scanning electron microscope (SEM) observation at each time interval. The surface roughness and wettability of studied ceramics were assessed using a surface profilometer and water contact angle. Differences in the cellular viability, surface roughness (Ra), and wet ability (wetting angle) of studied groups were compared by one-way analysis of variance and the Tukey multiple comparisons test (á = 0.05).

Results: The highest percentage of cell viability after 24 h, 72 h, and 168 h cultures was related to ZLS, LDS, and CZr, respectively. The lowest proliferation of fibroblast cells was shown in ZLS compared to other groups. SEM analysis showed that the CZr and LDS groups have better adhesion patterns and morphology. The surface of HyC groups was significantly less rough than other groups. Regarding the water wetting angle (wettability), the TZr and CZr showed significantly larger angles.

Conclusion: Within the limitation of this study, it can be concluded that CZr and LDS ceramics had better adhesion patterns and typical morphology. On the other hand, zirconia with a larger wetting angle can reduce the chance of bacteria adhesion to the surface.

Background: This study investigates the influence of dental pulp and periapical status on inflammatory mediators, particularly matrix metalloproteinases (MMPs), which contribute to tissue destruction around the teeth and the development of periodontitis. This study aimed to compare MMP-9 levels in the gingival crevicular fluid (GCF) between the cases of acute apical periodontitis, chronic apical periodontitis, and healthy controls before and after root canal treatment (RCT).

Materials and methods: This prospective, cohort study involved 19 samples each of acute and chronic periodontitis cases, both before and after RCT, along with 18 samples from healthy control teeth. The samples were collected from the GCF using paper cones. After 2 weeks of RCT, the process was repeated. MMP-9 levels were measured using the enzyme-linked immunosorbent assay technique. Statistical analysis was performed using the paired t-test and analysis of variance test and the significance level was set at < 0.05.

Results: Before treatment, there was no significant difference in MMP-9 levels between the healthy (0.476 μg/μL) and acute (0.48 μg/μL) groups; however, significant differences were observed between the healthy and chronic (0.534 μg/μL) groups. In addition, MMP-9 levels differed significantly between the acute and chronic groups before treatment. Post-treatment, the healthy group showed no notable difference compared to either patient group. However, a significant difference was observed between the acute (0.445 μg/μL) and chronic (0.491 μg/μL) groups after treatment.

Conclusion: Our findings suggest that MMP-9 levels in GCF increase during periapical inflammation and decrease after endodontic treatment. MMP-9 may serve as a potential diagnostic biomarker for pulp and periapical inflammation, enhancing our understanding of these clinical conditions and informing future therapeutic strategies.

Background: Dental caries stands as one of the most prevalent dental concerns, with early diagnosis being pivotal in clinical dentistry. Cone-beam computed tomography (CBCT) emerges as a widely utilized modality for dental caries identification, owing to its significant advantages. However, there remains a considerable knowledge gap regarding the efficacy of CBCT scans in detecting dental caries. In line with the as low as reasonably achievable principle, this study endeavors to evaluate the impact of amalgam fillings on the precision of occlusal caries detection in CBCT.

Materials and methods: This in vitro study employed a set of 102 extracted human teeth samples. Among these, six molar teeth were used to create mesial-occlusal-distal amalgam restorations. The remaining teeth were placed in the dental sockets of a dry human skull to restore proximal contacts. CBCT images were obtained and examined by two observers, while histopathological examination was conducted using a stereomicroscope. Comparative analysis of CBCT images and histopathological data was performed using the McNemar test in SPSS software (α = 0.05).

Results: The McNemar test results indicated that the nonrestoration group showed greater sensitivity and lower specificity in CBCT imaging than the amalgam-restored tooth group.

Conclusion: The findings suggested that the CBCT technique did not demonstrate effectiveness in diagnosing dental caries around amalgam restorations.

Background: Various topical gels, varnishes, and fluoride gels are being used by dentists for the treatment of White spot lesions (WSLs). The remineralizing effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), nano-hydroxyapatite (nHAp), and lasers has been proven earlier. This study was designed to evaluate the remineralizing effect of nHAp and CPP-ACP with and without erbium-doped yttrium aluminum garnet (Er: YAG) laser irradiation on demineralized primary enamel. The aim of this study was to evaluate the effect of CPP-ACP and nHAp with and without Er:YAG laser irradiation on the microhardness and surface morphology of demineralized primary enamel.

Materials and methods: The present study is an experimental in vitro study. Fifty extracted primary incisors were selected for the study. Following cleaning and sectioning, teeth were embedded in acrylic. The tooth models were divided into four groups randomly - Group 1 (CPP-ACP), Group 2 (nHAp), Group 3 (CPP-ACP + laser), and Group 4 (nHAp + laser). The baseline, postdemineralization, and postremineralization Vickers hardness testing was performed. One sample from each group was analyzed by scanning electron microscopy. Descriptive statistics such as frequencies and percentages for categorical data, mean and standard deviation for numerical data were depicted. The normality of numerical data was checked using the Shapiro-Wilk test. The level of significance was kept at 5%. Intergroup comparison (>2 groups) was done using one-way analysis of variance followed by pair-wise comparison using the post hoc test.

Results: There was a statistically significant increase in surface microhardness in each group after remineralization. The highest increase in microhardness value was seen in Group 4 (nHAp + laser) followed by Group 3 (CPP-ACP + laser) and the least in Group 1 (CPP-ACP). Similar observations were made in scanning electron microscopic images. This indicated that nHAp has a comparable, if not better ability for remineralization than CPP-ACP. The remineralizing capacity of both the remineralizing agents was seen to be improved in this study when simultaneous laser application was employed.

Conclusion: Currently, the evidence supporting the efficacy of nHAp dentifrices and laser in primary teeth is limited. Additional long-term in vivo studies employing standardized protocols and large sample sizes are necessary to draw definitive findings about the effect of remineralizing agents and lasers on primary enamel.

This review provides an overview of structure equation modeling (SEM) and its applications in dental research. SEM is a statistical technique that allows researchers to examine the relationships between variables and is useful for analyzing data from a wide range of research designs, including cross-sectional, longitudinal, and experimental studies. The process involves specifying a theoretical model, testing the model with data, and evaluating the model fit. It has been used in dental research to investigate a wide range of topics, including dental diseases, oral health-related quality of life, and dental anxiety. SEM is particularly useful in modeling the relationships between various risk factors and dental diseases and also has the potential to provide a deeper understanding of the multifactorial nature of dental diseases such as periodontitis, dental caries, and oral cancer. Moreover, the insights provided can aid in the development of effective strategies for the prevention and treatment of dental diseases. It is a powerful statistical tool that can be used by dental researchers to gain a better understanding of the intricate interplay of factors that underlie dental diseases and other oral health-related outcomes.

Background: Oral squamous cell carcinoma (OSCC) is the most common oral cavity cancer and may occur following oral epithelial dysplasia (OED). Cancer stem cells (CSCs) can self-renew and multi-directionally differentiate to promote tumorigenesis with high expression of cluster of differentiation (CD) 24 and CD44 markers. CSCs play a pivotal role in tumor development, drug resistance, and relapse after treatment. We aimed to evaluate the correlation between both marker expressions and clinicopathological indices in OED and OSCC patients.

Materials and methods: In this follow-up study, we could access 37 patients, including 12 OEDs and 25 OSCCs (Grade I: n = 9, Grade II: n = 8, and Grade III: n = 8). Data were analyzed using SPSS software (version 26) and log-rank tests, Fisher's exact test, Chi-square, and one-way ANOVA. P < 0.05 was considered statistically significant.

Results: There was no significant difference in the expression of CD24 and CD44 markers between the study groups (P > 0.05) and the expression of both markers and clinicopathological indices in the study groups (P > 0.05). The mean and standard deviation of overall survival (OS) were 54.46 ± 43.08 with a range of 6-193 months, and they were 8.24 ± 15.34 months with a range of 0-70 months for disease-free survival (DFS) in patients, respectively. The average of DFS in Grade I was significantly lower than the OED (P = 0.002) and Grade II (P = 0.039) groups. The OS average in the Grade I (P = 0.014) and Grade III (P = 0.004) groups was statistically lower than the OED group.

Conclusion: Although more than half of the patients demonstrated high expression of both markers, there was no statistically significant difference between them and clinicopathological indices.