Journal of Dental Research, Dental Clinics, Dental Prospects最新文献

Background: Tomato, renowned for its tooth-whitening properties due to its hydrogen peroxide and peroxidase enzyme content, requires formulation for enhanced applicability. This study assessed the dental whitening efficacy of a patch containing tomato juice as the active ingredient.

Methods: Tomato juice patches were formulated at concentrations of 55%, 60%, and 65%. A control group (C) containing a 12% hydrogen peroxide patch was also included. A matrix layer of the patches was prepared using the solvent casting method at 40 for 18 h, with Tegaderm^TM applied as the backing layer. For the dental whitening procedure, each group of patches was applied to the labial surface of anterior stained teeth (n=6/group) for 3 h, repeated 14 times. Tooth brightness was evaluated qualitatively and quantitatively using digital dental photo CIEL*a*b* analysis. Meanwhile, enamel surfaces were examined under a scanning electron microscope (SEM). Repeated-measures analysis of variance (ANOVA) was employed for statistical analysis.

Results: The application of tomato juice patches led to enhanced tooth brightness. The patch containing 65% tomato juice significantly improved stained tooth brightness (P<0.05). SEM analysis revealed less enamel erosion with the 65% tomato juice patch compared to the 12% hydrogen peroxide patch.

Conclusion: Tomato juice patches effectively increased tooth brightness while minimizing demineralization. Further research is needed to optimize formulation and explore its potential.

Background: This in vivo study assessed the accuracy of single-tooth monolithic zirconia crowns made using an intraoral scanner (IOS) and computer-aided design/computer-aided manufacturing (CAD/CAM) technology.

Methods: Thirty patients requiring single posterior crowns were selected. The teeth were prepared with a deep chamfer finish line with a 1-mm extension subgingivally and a 1-mm reduction in all surfaces by one prosthodontist. The gingival margins were retracted using a gingival retraction paste before making impressions using a Trios scanner. All the digital impression files were sent to one laboratory using the dental designer software (3Shape, Copenhagen, Denmark). After completing the milling and sintering processes, the crowns were dyed and glazed. After removing the temporary crown, the qualitative assessment of proximal contacts of definitive monolithic zirconia crowns was performed according to the CDA criteria. Data were analyzed with Friedman's two-way analysis and independent t-test at α=0.05.

Results: The difference in axial and total gaps between premolar and molar teeth was not significant; however, the mean marginal gap of molars was higher than that of the premolars (P=0.043). Furthermore, the comparison of the axial, total, and marginal gaps between the upper and lower jaws showed no significant difference (P>0.05). The distribution of occlusal and proximal contacts indicated 60% and 66.7% proper contacts and no contacts in 6.7% and 10% of cases, respectively.

Conclusion: Using IOSs could result in accurate monolithic zirconia crowns in terms of adaptation. Also, most occlusal and proximal contacts did not need any adjustments.

Background: This research assessed the compressive strength and microhardness of glass-ionomer cement (GIC) after incorporating seashell nanoparticles and evaluated the inert fluoride-releasing ability.

Methods: Seashell nanoparticles were synthesized by a mechanical grinding protocol. These particles were characterized by transmission electron microscopy and energy dispersive x-ray and added to the glass-ionomer powder in a weight-to-weight ratio. Seventy-five study samples were distributed into eight samples for each study group (control, 5%, and 10% seashell) to have 24 samples for each test of the study (compressive strength, microhardness, and fluoride release). One sample per group was prepared for the Fourier transform infrared spectroscopy (FTIR) test. The fluoride ion release was measured after one and four weeks of incubation period at 37 ºC, while other tests were conducted after 24 hours of incubation.

Results: In all the test variables, the 10% seashell group showed the highest significant mean, followed by the 5% seashell and the control group. However, there was no significant difference between the 5% and 10% seashell groups in the first week of fluoride release.

Conclusion: According to the results, 10% seashell nanoparticles were the best to improve the mechanical properties of GIC and boost the fluoride-releasing potential.

Background: The accurate timing of growth modification treatments is crucial for optimal results in orthodontics. However, traditional methods for assessing growth status, such as hand-wrist radiographs and subjective interpretation of lateral cephalograms, have limitations. This study aimed to develop a semi-automated approach using machine learning based on cervical vertebral dimensions (CVD) for determining skeletal maturation status.

Methods: A dataset comprising 980 lateral cephalograms was collected from the Department of Orthodontics, Shahid Beheshti Dental School in Tehran, Iran. Eight landmarks representing the corners of the third and fourth cervical vertebrae were selected. A ratio-based approach was employed to compute the values of C3 and C4, accompanied by the implementation of an auto_error_reduction (AER) function to enhance the accuracy of landmark selection. Linear distances and ratios were measured using the dedicated software. A novel data augmentation technique was applied to expand the dataset. Subsequently, a stacking model was developed, trained on the augmented dataset, and evaluated using a separate test set of 196 cephalograms.

Results: The proposed model achieved an accuracy of 99.49% and demonstrated a loss of 0.003 on the test set.

Conclusion: By employing feature engineering, simplified landmark selection, AER function, data augmentation, and eliminating gender and age features, a model was developed for accurate assessment of skeletal maturation for clinical applications.

Background: Although the benefits of low-level laser therapy (LLLT) in soft tissue healing have been demonstrated, the effects of laser on bone have remained controversial. This study investigated the impact of postoperative 660-nm LLLT on the radiographic crestal bone loss of fresh-socket dental implants.

Methods: Thirty patients referred to the Department of Oral and Maxillofacial Surgery for tooth extraction and placement of fresh-socket implants were selected and assigned to two groups: laser (intervention) and no-laser (control) groups. Immediately after tooth extraction, the implant was inserted into the tooth socket. 660-nm LLLT was immediately started after surgery and was repeated three times per week for two weeks. Bone quantification at the implant site was assessed using periapical intraoral radiographs and computerized software immediately after surgery and after six months.

Results: This study showed a statistically significant difference in mean bone resorption between the mesial and distal aspects of the two groups, with lower bone resorption in the laser group compared to the no-laser group.

Conclusion: The results of this study suggest that LLLT can effectively reduce bone resorption in fresh-socket implant placement. This might indicate the positive effect of LLLT on bone resorption reduction.

Background: This study evaluated the gingival crevicular fluid (GCF) and Peri- implant crevicular fluid (PICF) concentrations of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and active metalloproteinase-8 (a-MMP-8) in sites with healthy conditions vs. sites affected by periodontitis (PER) and peri-implantitis (PIM).

Methods: Periodontally healthy (PH) sites with PER, sites with peri-implant health (PIH), and sites with PIM were investigated intra-individually, according to the inclusion criteria of each group. Probing pocket depth (PPD), plaque index, gingival index, and the presence or absence of bleeding on probing (BoP) were evaluated. In GCF and PICF samples, IL-1β, IL-6, and TNF-α were quantified by ELISA Duoset® kit in combination with Ultramark® micro-ELISA digital reader; a-MMP8 concentration was analyzed by a chairside test (Perio/ImplantSafe®) in combination with a digital reader (ORALyzer®).

Results: The concentrations of IL-6 and IL-1β, TNF-α, and a-MMP-8 were significantly higher in the PIM and PER sites compared to healthy sites (P<0.05). Significantly higher concentrations of IL-1β and a-MMP-8 were found in PIM vs. PER sites (P<0.05), while the concentrations of IL-6 and TNF-α did not differ between the PIM and PER groups (P>0.05).

Conclusion: aMMP-8, IL-6, IL-1β, and TNF-α presented higher GCF/PICF concentrations in diseased periodontal and peri-implant sites. However, only the concentrations of IL-1β and a-MMP-8 were significantly higher in PIM than in PER sites.

This review aims to collate and analyze the existing evidence on the comparison of external apical root resorption (EARR) in subjects treated with clear aligners (CAs) and fixed appliances (FA). An electronic search was conducted in six databases for articles published in all languages until July 2023. Studies that evaluated EARR in subjects treated with CAs and FAs were included. The RoB 2 tool for RCTs and the ROBINS-I tool for non-randomized studies were used to analyze the risk of bias (ROB). A random effects meta-analysis was performed to assess EARR extent in maxillary and mandibular anterior teeth for subjects treated with CAs and FAs. Ten studies (eight retrospective, one RCT, and one CCT) were included in this review, out of which six studies reported a moderate ROB, one reported a serious ROB, and three reported a low ROB on qualitative analysis. The quantitative analysis of six studies revealed a significant intergroup difference (P<0.05) in the mean EARR for maxillary central (SMD=-0.62, P<0.00001) and lateral incisors (SMD=-0.47, P=0.01) with a moderate heterogeneity (I²=56%), as well as the mandibular central incisors (SMD=-0.27, P=0.04) with high heterogeneity (I²=79%). EARR was lower in subjects treated with CAs than FAs. A moderate quality of the available evidence suggests that EARR was less evident in subjects treated with CAs when compared with FAs.

Background: This study assessed the impact of chelating agents, 17% ethylenediaminetetraacetic acid (EDTA), 10% citric acid (CA), and 18% etidronic acid (HEDP), on root dentin mineral content. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was applied to analyze changes, and the push-out bond strength test was used to measure dentin adhesion of Well-Root ST, a bioceramic root canal sealer.

Methods: A total of 80 extracted single-rooted lower premolar teeth were included in this study and randomly divided into four groups (n=20): group 1 (17% EDTA), group 2 (10% CA), group 3 (18% HEDP), and group 4 (distilled water, control). After irrigation and drying, SEM-EDS was applied to analyze eight samples from each group at coronal, middle, and apical root regions for mineral content and SEM images. The remaining 12 samples underwent a push-out bond strength test using Well-Root ST sealer and gutta-percha. Kruskal-Wallis and Dunn's tests were used for statistical analyses.

Results: Statistically significant differences were found between groups (P<0.05). SEM-EDS showed significant differences in C, O, Ca, P, and Ca/P content, with no significant differences in Na and Mg. Push-out bond strength was significantly higher in the 17% EDTA, 10% CA, and 18% HEDP groups compared to the control group, with no significant differences between chelating agents.

Conclusion: Chelating agents altered root dentin mineral content and improved the adhesive properties of the bioceramic sealer. These findings highlight the importance of considering the selection and use of chelating agents in the clinical practice for root canal treatment.

Background: Preterm birth is a heterogeneous condition with multiple underlying causes, and periodontal diseases are one of them. Approximately 900000 preterm births are reported in Pakistan each year. Oral infections such as periodontitis during pregnancy are associated with adverse pregnancy outcomes such as low birth weight and preterm births. However, different studies have reported contradictory findings. We conducted a cross-sectional study to assess the association of preterm birth with oral infection in pregnancy.

Methods: We conducted a cross-sectional analytical study on 400 postpartum pregnant women in Khyber Teaching Hospital, Peshawar. Only women within the age bracket of 18‒40 years were recruited. Data were collected by an interview-based structured questionnaire. The extent and severity index were used to assess the periodontal health of participants. Frequency tables were generated, and the chi-squared test was used to determine associations between different categorical variables.

Results: The mean age of the participants was 25.8±4.9 years. Approximately 87.5% of the women had generalized periodontitis. Approximately 68% of mothers had moderate severity of periodontitis. The extent index showed no notable difference between the preterm and full-term birth groups. In contrast, the severity index displayed a statistically significant difference between the preterm and full-term birth groups.

Conclusion: The majority of women had generalized periodontitis. The severity index demonstrated a significant association between maternal periodontitis and preterm births. There was no association between the age of mothers and preterm births. Complications in pregnancy were not associated with preterm births.

Background: Zirconia-reinforced lithium disilicate (ZLD) is a promising material for esthetic dental restorations due to its strength, translucency, and color stability. However, its durability under accelerated aging conditions needs further investigation. The present in vitro study evaluated the effect of UV accelerated aging on the translucency and color stability of ZLD at varying thicknesses, using IPS e.max Press (LD) as a reference.

Methods: Seventy-two samples were divided into two groups: high translucent (HT) Vita Ambria (ZLD) and IPS e.max Press (LD) (n=36, each). Each group was further subdivided into four thicknesses: 0.5, 1.0, 1.5, and 2.0 mm (n=9). The samples were fabricated, polished, and subjected to UV weathering for 384 hours, simulating one year of clinical service. Translucency and color changes were assessed using a spectrophotometer. Data were analyzed using SPSS 20, with independent t-test, paired t-test, and one-way ANOVA at a significance level of P≤0.05.

Results: Vita Ambria exhibited significantly higher translucency before and after aging compared to IPS e.max press at all thicknesses (P=0.000). In both materials, translucency decreased when the thickness increased (P=0.000), observed before and after UV aging. Vita Ambria also displayed a greater color change (ΔE=2000) compared to IPS e.max press across all thicknesses (P=0.000).

Conclusion: ZLD exhibited higher translucency than LD before and after accelerated artificial aging, indicating that the accelerated aging process adversely impacted the optical properties of the tested material. However, LD demonstrated superior color stability.