International Journal of Dentistry最新文献

Purpose: To evaluate the influence of edible liquids on the characteristic properties of 3D printable materials compared to conventionally used dental resin acrylic.

Method: Dental polymethyl methacrylate (PMMA) specimens were fabricated from preformed molds while polylactic acid (PLA) and polyethylene terephthalate glycol (PETG) specimens were 3D printed using fused deposition modelling at 0.1 mm layer thickness. All specimen forms adhered to ISO 37:2017 and ISO 604:2002 specifications. Specimens underwent controlled immersion for 180 hr into different media (no immersion (control), oil, soda, milk, and caffeine). Changes in mass (g), plastic deformity (N/mm²), ultimate tensile stress (N), flexural deformity (N/mm²), and break force (N) were evaluated using analysis of variance.

Results: There was an increase in mass for all specimens following immersion with significant interactions between immersion media and the materials. The materials exhibited significant differences in plastic deformity (F (df) = 156.632(2), P  < 0.001), ultimate tensile stress (F (df) = 109.521(2), P  < 0.001), and break force (F (df) = 319.785 (2), P  < 0.001) with no significant interactions with immersion media (P > 0.05) on both accounts. Materials showed no significant differences in flexural deformity (F (df) = 2.693(2), P = 0.074) but with significant interactions (F (df) = 4.984(8), P  < 0.001) between acrylic and immersion media.

Conclusion: Commercially available 3D printable PLA and PETG filaments printed at 0.1 mm thickness possess approximately half the mechanical resilience as dental PMMA with comparable flexural deformity after exposure to edible liquids.

This study investigates the potential of incorporating akermanite and hardystonite nanoparticles (NPs) into commercially available zinc phosphate cement. Akermanite and hardystonite NPs were synthesized through a mechanical route and characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The NPs were then added to the cement at a concentration of 5 wt%, and the physical and biological properties of the resulting composite were evaluated. The results showed that the incorporation of NPs led to a significant reduction in porosity (from 12.4% to 5.6%) and a notable improvement in compressive strength (from 90 to 120 MPa) compared to the control group. MTT assay revealed that the cement containing NPs exhibited no significant toxicity and even promoted cell growth and proliferation. Specifically, cell viability increased by 15%, and cell proliferation rate increased by 20% compared to the control group. These findings suggest that the designed cement has suitable mechanical and biological properties, making it a promising material for dental and orthopedic applications.

Objectives: This study aimed to evaluate and compare palatal thickness in adults for the placement of mini-implants for miniscrew-assisted rapid palatal expansion (MARPE) appliances using cone-beam computed tomography (CBCT) in a sample of Iraqi-Kurdish people.

Materials and methods: CBCT scans from 68 Kurdish patients, aged between 18 and 30 years, were assessed retrospectively. Of these, 37 were males and 31 were females. The measurements were performed at 3 mm from the mid-palatal suture. T-zone was selected for the anterior points, at the level of the palatal cusps of 2nd premolars, and the posterior point at the level of mesio-palatal cusps of 1st molars bilaterally. Palatal thickness of males and females bilaterally, as well as anterior and posterior areas, were measured and compared. An independent t-test was applied for comparison for normally distributed data, and the Mann-Whitney test was utilized for nonnormally distributed data. Additionally, Bonferroni correction was implemented for p-value adjustment.

Results: The mean palatal thickness at the anterior area was 6.06 mm for males, 6.17 mm for females on the right side, 5.94 mm for males, and 5.99 mm for females on the left side. The mean palatal thickness at the posterior area was almost the same for both genders (4.40 mm for males and 4.44 mm for females) on the right side, 4.35 mm for males, and 4.54 mm for females on the left side. Statistically, no significant difference was recorded between males and females, as well as right and left sides in both anterior and posterior regions; however, a very highly statistically significant difference (p  < 0.001) was recorded when comparing total thickness, including both hard and soft tissue, between anterior and posterior regions.

Conclusions: CBCT proves a highly effective modality in assessing palatal thickness and suggesting ideal locations for orthodontic mini-screw placement. Our examination of palatal thickness in a sample of Iraqi-Kurdish individuals revealed no statistical difference between genders or sides, but significant variations were noted between anterior and posterior thicknesses. Comprehensive clinical and pre-expansion CBCT evaluations are crucial for precisely determining the optimal placement of MARPE devices in each patient, ensuring successful outcomes.

Objective: This study aimed to assess the effect of length of the relocated cervical margin with casting post and core (CP), prefabricated fiber post and composite core (PFP), and polyethylene fiber-reinforced composite (PEFRC) on fracture resistance and marginal integrity.

Materials and methods: In this in vitro study, 70 sound human maxillary premolars were divided into seven groups according to the type of post and core system and length of the relocated cervical margin (n = 10): control (no preparation), PFP-3, PEFRC-3, CP-3 with 3 mm of cervical margin relocation (CMR), PFP-6, PEFRC-6, and CP-6 (with 6 mm of CMR). The samples were restored with zirconia crowns (except the control group). Epoxy resin replicas were fabricated before and after thermomechanical loading. Marginal integrity was assessed at the luting cement-core, core-tooth, and luting cement-enamel interfaces under a scanning electron microscope (SEM) (×200). Fracture resistance and failure mode were subsequently assessed. Data were analyzed by independent t-test, paired t-test, ANOVA, Tukey-Games Howell, Mann-Whitney, Kruskal-Wallis, Wilcoxon, Mann-Whitney with Bonferroni correction, and Fisher-Freeman-Halton tests (α = 0.05).

Results: The marginal integrity of the groups with 3 mm of CMR followed the following order: PEFRC > PFP > CP at all interfaces (P  < 0.05). In 6-mm CMR groups, this order was CP < PFP = PEFRC at the luting cement-core and (CP < PEFRC) = PFP at the core-tooth interface. No significant difference was found in fracture resistance when comparing the 3-mm CMR groups with each other (P  > 0.05). PFP-6 showed higher FR than CP-6 (P  < 0.001). PEFRC-6 had no significant difference with PFP-6 and CP-6 (P  > 0.05). In each post and core system, 3-mm CMR groups showed higher marginal integrity and fracture resistance (P  < 0.05).

Conclusion: Increasing the length of the relocated cervical margin decreased the marginal integrity and fracture resistance of all three systems of CP, PFP, and PEFRC.

Objective: To evaluate, through a systematic literature review, whether periodontal status in HIV-infected individuals is different from those non-HIV-infected.

Materials and methods: A systematic search for published observational studies within six electronic databases and grey literature was conducted, PROSPERO database number CRD42020160062. Results from studies reporting clinical periodontal parameters: probing pocket depth, bleeding on probing, clinical attachment level, plaque index, and gingival index, in HIV- and non-HIV-infected individuals were reviewed. The quality of the assessment was evaluated according to the Joanna Briggs Institute Appraise Checklist.

Results: Twenty-three observational studies met the eligibility criteria and were included for analysis. The qualitative analysis indicated similarities in periodontal parameters within both groups, with no significant mean difference (MD) within both groups regarding clinical periodontal parameters; severe heterogeneity was also detected.

Conclusions: No significant differences were found in the periodontal profile of HIV-infected and non-HIV-infected individuals. However, the high heterogeneity among the studies calls for caution in interpreting these findings. Further investigations using standardized methods for periodontal evaluation are needed to clarify the association between HIV infection and periodontal conditions.

Objective: This study aims to systematically review and analyze the periodontal outcomes of presurgical orthodontic decompensation (POD) in patients with skeletal Class III malocclusion and to identify the key influencing factors. Material and Methods. We searched the Web of Science, PubMed, Scopus, Embase, and Cochrane Library databases. The outcomes included measurements related to periodontal soft or hard tissues.

Results: A total of 3,904 records were found, of which 10 were included. The meta-analysis revealed significant alveolar bone loss in mandibular incisors on both the lingual and labial sides during POD, with a more pronounced loss on the lingual side at the apex level and on the labial side near the crown. The maxillary incisors demonstrated significant bone loss, primarily on the lingual side. No significant bone loss was observed during postsurgical orthodontic treatment. Gingival recession was statistically significant but had a minor clinical impact. Incisor proclination was found to influence the gingival recession. However, no correlation was observed between bone loss and incisor proclination, vertical facial type, or sex.

Conclusions: POD for skeletal Class III patients results in alveolar bone loss, particularly on the lingual side at the mandibular incisors' apex level and labial side at the crown level, and clinically acceptable gingival recession.

Background: The aim of this study was to evaluate the changing levels of stress among dental students during 8 months of a basic manual skills course in the preclinical year and to examine the association between stress and dental performance.

Methods: A longitudinal study was conducted in the 2023 academic year in a total of 58 (male = 17 and female = 41; mean age = 26.43, range 22-33) undergraduate dental students at Tel Aviv University of dentistry during their fourth year of study. Depression Anxiety Stress Scale (DASS-21) and Dental Environment Stress (DES) questionnaires were used to assess the psychological well-being and the severity of DASS symptoms experienced by the students. The students' dental performances were assessed using two manual tests on plastic teeth. The questionnaires and the manual tests were used at three periods of time, T0, T1, and T2. Wilcoxon signed-rank tests were performed to compare the DASS scores and DES stressors of dental students between T0, T1, and T2. Kendall's nonparametric correlations were calculated to investigate the relationships of DES stressors and depression, anxiety, and stress scores with manual performance.

Conclusions: The perception of high stress by dental students is due to the stressful education process of the preclinical year. There is an inverse correlation between the lower level of anxiety and the increase level of dental performance with 74% of the variance in dental performance explained by the anxiety score. Work-related stressors such as manual skills might reduce dental performance in contrast to non-work-related factors such as financial obligations, personal issues, and family factors, which might increase student dental performance.

Surface modification and biomimetic approaches have been widely used to enhance bioinert substances. It is not very clear whether surface alterations and polymer coatings on titanium make it more biologically active and enhance cell adhesion. We tried to focus on the physical and biological characterization of surface-modified titanium disks. Four different surface modifications were done for the titanium disks, ranging from acid etching, sandblasting, polydopamine coating, and polydopamine-based chitosan coating, and were compared with disks without any surface modification. The disks were studied for physical characteristics like surface roughness and contact angle. Human gingival fibroblasts were used to investigate the biological effects of surface modification of titanium alloy surfaces. The wettability of chitosan-coated, acid-etched, and polydopamine-coated titanium was much better than that of the sandblasted surface, indicating that surface energy was higher for acid-etched and coated surfaces than others. The cell seeding with fibroblasts showed increased adhesion to the smoother surfaces as compared to the rougher surfaces. Polydopamine coatings on titanium disks showed the most favorable physical and biological properties compared to others and can be a good surface coating for in vivo implants.

Methods: Patients examined during postloading maintenance visits were included in this study. The presence of peri-implant mucositis, peri-implantitis and several patient- and implant-related independent variables was recorded. Statistical analysis was performed using the logistic regression analysis. The odds ratios (OR) of the potential association between each variable and the occurrence of peri-implant diseases were evaluated.

Results: Among the 114 participants with 403 implants, peri-implantitis was found in at least one implant of nine individuals (7.89%), and a total of 13 implants were affected by peri-implantitis (3.22%). The univariate regression analysis revealed a statistically significant association between arch (OR = 4.81; 95% CI = 1.27-31.36) and soft tissue thickness (OR = 4.07; 95% CI = 1.33-13.73) with the occurrence of peri-implantitis. The multivariate analysis confirmed the significant impact of soft tissue thickness (OR = 3.60; 95% CI = 1.16-12.24).

Conclusion: The occurrence of peri-implant diseases can be influenced by various factors. However, in order to accurately identify risk indicators, it is necessary to conduct long-term prospective studies.

Purpose: To analyze prosthetic complications of single screw-retained implant-supported metal-ceramic fixed prostheses (SSIMCFPs).

Materials and methods: A total of 457 medical records of patients treated with implants at the University Dental Clinic of the European University of Valencia from 2016 to 2022 were reviewed. Of the 335 SSIMCFPs evaluated, 222 were included. The following data were collected from medical records: age, sex, prosthesis location, implant diameter, type of antagonist, date of prosthesis placement, type of prosthetic complications, and the date of the occurrence of complications. Statistical analysis was estimated at the patient level with a simple binary logistic regression and at the prosthesis level, a simple logistic regression with generalized estimating equation models (p  < 0.05).

Results: A total of 222 SSIMCFPs were placed in 159 patients. The prevalence of complications was 23.3% at the patient level, equivalent to 21.6% of SSIMCFPs. A total of 48 complications were collected; screw loosening was the most frequent complication (16.2%), followed by ceramic fracture (3.1%), screw fracture (1.8%), and implant fracture (0.5%). There were no cases of abutment fracture. The mean time of the loosening of the screw was 10.5 months and ceramic fractures at 6.9 months. The factors that most influenced the occurrence of prosthetic complications were posterior position (p  < 0.001), implant diameter from 3.5 to 4.8 mm (p  < 0.01), and lower arch position (p  < 0.05).

Conclusions: The most frequent complication of SSIMCFP was loosening of the screw followed by ceramic fracture. The appearance of these complications usually occurred during the first year after SSIMCFP placement. Factors related to the occurrence of complications were mandibular posterior location and implant diameter from 3.5 to 4.8 mm.