European Journal of Dentistry最新文献

This review aims to provide an overall picture of the three-dimensional (3D) printing contributions to endodontic practice in treatment planning and execution. The methodology entails a comprehensive literature review of the technological processes and 3D printing applications in the field. Some key findings show that 3D printing is highly effective in producing the right dental models for training, helps in complex surgeries, and supports the transition toward personalized therapies. The review reveals that 3D printing has many benefits but that the broader adoption of this technology faces issues, including high technical requirements, high costs, and the need for safety standards. The study concludes that although in the future some challenges need to be addressed, the potential of 3D printing in endodontics is enormous and this means that the treatment methods of dentistry could be more efficient and innovative.

Objectives:  To investigate the association of E-cadherin single nucleotide polymorphisms (SNPs) with periodontitis and the potential of these SNPs for identifying susceptibility to periodontitis.

Materials and methods:  Periodontal clinical parameters were recorded followed by collecting venous blood for DNA extraction. Polymerase chain reaction was used to amplify target segments of the E-cadherin gene. Determination of the genotype and allele frequencies was performed using Sanger sequencing. All statistical analyses were performed using GraphPad Prism (version 9) using a statistically significant difference of p < 0.05.

Results:  A total of 207 participants were recruited into two groups of healthy controls (n = 105) and cases diagnosed with periodontitis stage 2 or 3, grade B or C (n = 102). Analyses indicated that the genotypes and alleles of rs3743674 and rs5030625 E-cadherin SNPs were significantly associated with periodontitis. Results from a binary regression model suggested that the presence of these SNPs may indicate susceptibility to periodontitis and increase the rate of progression. Linkage disequilibrium analysis indicated that E-cadherin variants rs3743674 and rs5030625, and rs10272115 and rs16260 were correlated in a nonrandom manner (r ² = 0.638 and 0.495, respectively).

Conclusion:  E-cadherin gene variants, rs3743674 and rs5030625, were associated with the periodontitis phenotype. These biomarkers may identify individuals susceptible to periodontitis and the rate of disease progression.

Objectives:  Pulp capping is a pivotal treatment in dentistry aimed at preserving pulp vitality. While calcium hydroxide has long been considered the gold standard in pulp capping materials, its long-term use can induce chronic inflammation, ultimately leading to pulp necrosis and affecting human health. In this context, ellagic acid, a natural compound with potent anti-inflammatory properties, emerged as a promising adjunct to mitigate inflammation associated with calcium hydroxide application, thereby sustaining pulp vitality. This study aimed to investigate the inflammatory response by alterations in neutrophil, macrophage, lymphocyte, and tumor necrosis factor-α (TNF-α) expression following the treatment with a combination of calcium hydroxide and ellagic acid.

Materials and methods:  Dental pulp perforation was made on 27 male Wistar rats on the upper first molar and then pulp capped with calcium hydroxide and ellagic acid. The pulp of the control positive group was capped with calcium hydroxide, and the control group was not capped. The teeth were then extracted after 1, 3, and 7 days posttreatment. The differences in the number of neutrophils, macrophages, lymphocytes, and TNF-α expression were analyzed using one-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) test.

Results: The treatment combination of calcium hydroxide and ellagic acid showed the lowest neutrophil number and TNF-α expression compared with the other groups (p < 0.05), while the macrophage and lymphocyte numbers were the highest compared with the other groups (p < 0.05).

Conclusion:  The combination of calcium hydroxide and ellagic acid as a pulp capping material exhibited a dual effect on the inflammatory response in dental pulp. These findings suggest that calcium hydroxide and ellagic acid modulate the inflammatory response in a complex manner, promoting a more controlled and potentially beneficial healing process.

Objective:  The aim of this randomized, controlled, split-mouth study was to compare full-mouth air polishing followed by ultrasonic debridement (known as Guided Biofilm Therapy [GBT]) versus traditional Scaling and Root Planing (SRP), in terms of pocket closure in patients with stages III and IV periodontitis.

Materials and methods:  The patients underwent periodontal therapy in two sessions. At the beginning of the first session, quadrants I and IV and II and III were randomly assigned to GBT or SRP treatment. Periodontal parameters were collected at baseline, 6 weeks (T1), and 3 months (T2) after therapy. The primary outcome was the number of experimental sites (pocket probing depth [PPD] >4 and <10 mm) becoming closed pockets (PPD ≤ 4 mm bleeding on probing [BOP] negative) at T1 and T2. Secondary outcomes were PPD, recession, clinical attachment level, BOP, and plaque index variations at the experimental sites and treatment time.

Statistical analysis:  A 10% difference in the primary outcome between the two protocols was set as the threshold to define inferiority/noninferiority of the test treatment. The primary outcome was modeled using a generalized estimating equation model to account for intrapatient measurement correlation. The estimates are reported as differences between groups' percentages (treatments or time points) and corresponding 95% confidence interval (95% CI). All analyses assumed a significance level of 5%.

Results:  A total of 32 patients were selected. Mean PPD (mm) reduced from 6.23 (6.06-6.40) to 3.33 (3.06-3.61) at T2 for GBT, and from 6.21 (6.04-6.38) to 3.32 (3.11-3.53) at T2 for SRP. Both treatments reached a comparable percentage of closed pockets at T1 (77.9% for GBT vs. 80.1% for SRP, p = 0.235) and T2 (84.1% for GBT vs. 84.4% for SRP, p = 0.878), with no statistically or clinically significant difference. GBT and traditional SRP with ultrasonic and hand instruments reach satisfactory clinical results in the active treatment of patients with stages III and IV periodontitis, with comparable rates of closed pockets and treatment time.

Conclusion:  GBT is a suitable option in the active phase of periodontitis management in patients with stages III and IV periodontitis.

Objectives:  Histone modification in odontogenic lesions is mostly unexplored. Trimethylation of histone H3 at lysine residue 9 (H3K9Me3) has been studied in various pathologic conditions and showed biological significance promising for future therapeutic application. This study aimed to investigate the level and clinical relevance of the H3K9Me3 histone modification in odontogenic cysts and tumors.

Materials and methods:  A total of 105 cases of odontogenic lesions, comprising 30 odontogenic keratocysts (OKCs), 30 adenomatoid odontogenic tumors (AOTs), 30 ameloblastomas, and 15 dental follicles, were included in the study. The paraffin-embedded tissues were immunohistochemically stained for H3K9Me3. Both the intensity and the distribution of staining were evaluated and calculated as H-score. The correlation between the H3K9Me3 expression and the clinical characteristics of each lesion was evaluated.

Statistical analysis:  The Kruskal-Wallis test followed by Bonferroni's correction was performed to assess the differences in H-score among groups. In addition, Pearson's chi-squared test or Mann-Whitney U test was used to analyze potential factors that could affect protein expression.

Results:  The reduced enamel epithelium of the dental follicle showed uniformly strong H3K9Me3 expression. All odontogenic cysts and tumors examined demonstrated a significantly reduced H3K9Me3 level compared with dental follicles. The AOT showed the lowest H3K9Me3 level, followed by OKC and ameloblastoma. Its immunoreactivity was mainly localized in the basal and parabasal cells of OKC and the whorled/duct-like structures of AOT. Ameloblastoma exhibited marked variation in the H3K9Me3 level among cases. Notably, the upregulated H3K9Me3 was related to multilocularity of OKC and ameloblastoma.

Conclusions:  Histone H3K9 methylation is differentially expressed in odontogenic cysts and tumors. This epigenetic modification may contribute to the pathogenesis and aggressive behavior of odontogenic lesions.

Objectives:  This study aimed to assess the influence of two key design parameters on the torsional resistance of endodontic rotary files: the ratio of the equivalent radius (re ) to the polar moment of inertia (J), or re /J ratio, and the percentage of the inner core area. Understanding these factors can guide the development of files with improved performance during root canal procedures.

Materials and methods:  Finite element analysis was employed to simulate the behavior of rotary files under torsional loading conditions. This method allowed for the investigation of maximum shear stress across various cross-sections (D₄-D₁₆) of the files. The relationship between the re /J ratio and the maximum shear stress was also evaluated. To assess the impact of cross-sectional design modifications on stress distribution, the study analyzed files with progressively changing configurations.

Results:  Regions situated outside the inner core circle experienced lower shear stress compared with a circular shaft. Furthermore, a strong linear correlation was observed between the maximum shear stress experienced by the file, the applied torque during operation, and the re /J ratio. Significantly, the study established a connection between the percentage of the inner core area and the torsional resistance of the file. Files with a larger inner core area exhibited a lower coefficient (C) within a newly derived torsional formula. This lower C value directly translated to a reduction in the maximum shear stress experienced by the file. In essence, files with a higher percentage of inner core area demonstrated enhanced torsional resistance, allowing them to withstand higher torsional loads encountered during root canal procedures.

Conclusion:  This study identified the re /J ratio and the percentage of inner core area as the most critical design factors influencing the torsional resistance of rotary files. Files with a lower re /J ratio and a larger inner core area experienced lower shear stress, resulting in enhanced torsional resistance and potentially reducing the risk of torsional fracture during use. These findings offer valuable insights for both clinicians selecting rotary files and manufacturers designing future iterations, ultimately contributing to improved safety and efficacy during root canal treatments.

Objective:   Temporary anchorage devices (TADs) have revolutionized fixed orthodontic appliance treatment through anchorage controlling in the clinic and play an essential role in resolving many complex cases. Due to the limited space, there is a risk of injury to the roots while using interradicular microimplants. Therefore, the infrazygomatic crest (IZC) area can be an alternative mini-implant insertion site in the maxillary arch. The aim of the study was to evaluate the primary stability, pain perception, sinus penetration, late stability, and failure rate with two mini-implant lengths in the IZC area.

Materials and methods:  Forty-eight mini-implants (Tusk Dental Co., Ltd., Canada) with two different lengths (length/diameter: 12/2 and 14/2 mm) were grouped by length (24 per group) and inserted bilaterally into the IZC area of 24 patients. The data were statistically analyzed, considering a significance level of p < 0.05.

Results:  Sinus penetration prevalence did not differ significantly between 12-mm (54.2%) and 14-mm (62.5%) mini-implants (p > 0.05). Primary stability was significantly higher with the 14-mm mini-implants (p < 0.05). The failure rate did not differ significantly between the 12-mm (20.8%) and 14-mm (16.7%) mini-implants (p > 0.05).

Conclusion:  While the failure rate was similar between 12- and 14-mm mini-implants, the 14-mm mini-implants were more likely to damage adjacent structures. Therefore, shorter mini-implants should be preferred over longer mini-implants for most cases requiring IZC TADs.

Trial registration id:  ClinicalTrials.gov identifier: NCT06293872.

Objective:  The failure of dental implant treatments is predominantly attributed to peri-implantitis, which entails chronic inflammation within the peri-implant tissue, ultimately leading to tissue degradation. Addressing this condition, human umbilical cord mesenchymal stem cell (hUCMSC) transplantation serves as a regenerative therapy; however, concerns regarding the viability and efficacy of transplanted cells in inflamed regions persist. Hypoxic preconditioning of hUCMSCs has emerged as a potential strategy for augmenting their regenerative and immunomodulatory capacities. This study aimed to evaluate the expression of inflammatory (tumor necrosis factor [TNF]-α) and bone regenerative biomarkers (nuclear factor of activated T-cell [NFATc1], osteocalcin, collagen type I alpha 1 [COL1α1]) within peri-implantitis models subsequent to the transplantation of hypoxia-preconditioned hUCMSCs.

Materials and methods:  Peri-implantitis models were established through the insertion of implants into the femur bone of 42 Wistar strain Rattus norvegicus, followed by intrasocket injection of lipopolysaccharide. The experimental animals were categorized into three groups (control, normoxia, and hypoxia) and underwent observation on days 14 and 28. The expression levels of TNF-α, NFATc1, COL1α1, and osteocalcin were evaluated using immunohistochemical staining, and the resulting data were subjected to one-way analysis of variance analysis (p < 0.05).

Results:  Transplantation of hypoxia-preconditioned hUCMSCs significantly ameliorated inflammation and osteoclastogenesis, as evidenced by significant reductions in TNF-α and NFATc1 expression compared with the control group. Furthermore, hypoxic preconditioning of hUCMSCs demonstrated a significant elevation in the expression of osteocalcin and COL1α1 relative to the control group.

Conclusion:  The transplantation of hypoxia-preconditioned hUCMSCs exhibited a capacity to ameliorate inflammation and enhance bone regenerative processes in peri-implantitis rat models.

Objective:  To compare bite force distributions in corresponding mouth regions between postorthodontic patients who underwent nonextraction and extraction approaches using the T-Scan III system (Tekscan, Inc, Massachusetts, United States).

Materials and methods:  Thirty-six postorthodontic patients were divided into two groups: (1) 18 subjects with the nonextraction treatment and (2) 18 subjects with the extraction of four first-premolar treatments. The measurements were performed using the T-Scan to collect the occlusal bite force at the maximal intercuspal position to generate the bite force in the anterior region (incisors and canines) and posterior region (premolars and molars), the bite force in individual teeth, and the anteroposterior bite force ratio (A-P ratio).

Statistical analysis:  The mean bite force in each region, individual teeth, and the A-P ratio were compared between the two groups by the Mann-Whitney's U-tests. Within-group comparisons of the mean bite force in each region were performed using Wilcoxon's signed rank tests.

Results:  The bite force in anterior and posterior regions, and the A-P ratio of the nonextraction group show no significant difference compared with the extraction group (p > 0.05). For individual teeth (central incisors, lateral incisors, canines, second premolars, first molars, and second molars), each tooth exhibited nonsignificantly different bite forces (p > 0.05) except for the second molars. The second molars in the nonextraction group had significantly less bite force than in the extraction group (p = 0.001). The comparison of occlusal bite force between the right and left sides showed that in the nonextraction group, the right side had significantly greater force (p < 0.05). In the extraction group, there was no significant difference between the sides (p > 0.05).

Conclusion:  Both nonextraction and extraction orthodontic treated patients exhibited the similar bite force distribution patterns in regions and individual teeth except for the higher occlusal force on the second molars in the extractions compared with the nonextractions.

Objectives:  This study aimed to compare the intensity of postoperative pain following the final rinse using cold saline compared with room temperature saline and occlusal reduction.

Materials and methods:  A prospective, parallel, double-blinded randomized controlled trial was conducted on 69 first mandibular molars diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis. Single-visit root canal treatment was performed; access cavity preparations and chemomechanical preparations were carried out using the ProTaper Gold rotary system under copious irrigation using 3% sodium hypochlorite and 17% EDTA. The patients were divided into three groups (n = 23): control group: room temperature saline (25°C) final rinse without occlusal reduction; cryotherapy group: cold saline (2.5-4°C) final rinse without occlusal reduction; and occlusal reduction group: room temperature saline with occlusal reduction. Pain scores were recorded using the visual analog scale preoperatively and postoperatively via telephone at 6, 24, 48, 72 hours, and 7 days intervals. Age data were analyzed using one-way analysis of variance followed by Tukey's post hoc test. Pain score data were analyzed using Kruskal-Wallis' test followed by Dunn's post hoc test for intergroup comparisons and Friedman's test followed by Nemenyi's post hoc test for intragroup comparisons. Correlations were analyzed using Spearman's rank-order correlation coefficient. The significance level was set at p < 0.05 within all tests.

Results:  Cryotherapy reduced postoperative pain compared with the control group with a statistically significant difference at 24 hours only (p = 0.016). At other intervals, no statistically significant difference in pain score was measured between all three groups (p > 0.05). After 7 days, all patients recorded a zero pain score.

Conclusion:  Cryotherapy was as effective as the occlusal reduction in reducing postoperative pain in cases of symptomatic irreversible pulpitis with symptomatic apical periodontitis, significantly more than the control group.