Clinical and Experimental Dental Research最新文献

Objectives

This study is the first to integrate 3D finite element modeling, in vitro validation, and preclinical animal experiments to determine the efficacy of low-intensity thermal stimulation (LITS) in enhancing dental implant osseointegration. The study seeks to provide experimental evidence for applying thermal stimulation as a possible approach to enhance osseointegration.

Material and Methods

A 3D finite element implant-femur model and in vitro implant-bone system were developed to simulate heat distribution. LITS conditions (50°C/5 s) were validated to avoid exceeding the osteoblast safety threshold (47°C). Eighteen rabbits received femoral implants divided into: control (no heating), T1 (single 50°C/5 s heating cycle), and T2 (three cycles). Outcomes included implant stability (IST), reverse torque, bone volume fraction (BV/TV), and histomorphometric osseointegration rate at 6 weeks.

Results

Finite element and in vitro analyses confirmed 50°C/5 s as the optimal protocol, maintaining implant surface temperatures ≤ 46.3°C and complete thermal recovery within 1 min. T1 significantly increased in vivo rabbit model reverse torque (p < 0.05) and BV/TV (p < 0.05), while T2 showed no BV/TV improvement. Both T1 and T2 exhibited higher osseointegration rates (p < 0.05). Implant stability (IST) remained unchanged across groups (p > 0.05).

Conclusion

LITS at 50°C/5 s safely enhances early osseointegration in rabbits, increasing biomechanical anchorage and peri-implant bone formation. This study provides preliminary experimental evidence for the potential of thermal application in enhancing implant osseointegration.

Objectives

This study aimed to evaluate the microshear bond strength (µSBS) of resin-modified glass ionomer cement (RMGIC) to primary dentin and the fracture resistance of primary molars restored with RMGIC, with and without the incorporation of mesoporous zinc oxide nanoparticles (ZnO NPs) and bacterial cellulose nanocrystals (BCNCs).

Materials and Methods

A total of 100 extracted primary mandibular second molars were divided into two tests: the µSBS test (40 teeth) and the fracture resistance test (60 teeth). The µSBS test included four groups: (1) RMGIC (control), (2) RMGIC + 5 wt.% mesoporous ZnO NPs, (3) RMGIC + 1 wt.% BCNCs, and (4) RMGIC + 5 wt.% mesoporous ZnO NPs and 1 wt.% BCNCs. The fracture resistance test included these groups along with an intact teeth group (positive control) and a prepared but unrestored teeth group (negative control). A universal testing machine was used for all mechanical tests.

Results

The RMGIC + 1 wt.% BCNCs group exhibited the highest µSBS (6.35 ± 1.98 MPa), significantly surpassing the control and other experimental groups (p < 0.001). For fracture resistance, the negative control had the lowest value (422.70 ± 44.50 N, p < 0.05), while the positive control had the highest, significantly outperforming all groups except RMGIC + 1 wt.% BCNCs (p > 0.05). The RMGIC + 1 wt.% BCNCs group (1280.40 ± 340.87 N) demonstrated significantly greater fracture resistance than both RMGIC and RMGIC + 5 wt.% mesoporous ZnO (p < 0.05).

Conclusions

Incorporating 1 wt.% BCNCs into RMGIC significantly enhanced both microshear bond strength and fracture resistance, leading to a higher proportion of restorable fractures. The positive correlation between bond strength and fracture resistance suggests that BCNCs-modified RMGIC is a promising restorative material for improving durability in primary molars.

Objectives

Penicillin's impact on enamel defects remains understudied, particularly regarding its ability to cause structural issues even at therapeutic doses.

Material and Methods

Pregnant Wistar rats received daily gavage from gestational day 13–22 with saline (control), 130 mg/kg tetracycline, 50 mg/kg penicillin, or 100 mg/kg penicillin. After birth, pups received the same treatment for 12 days. Upper first molars were analyzed for enamel/dentin thickness, maturation, and histopathological changes.

Results

Tetracycline significantly reduced enamel and dentin thickness, disrupted their development, and caused flattening of the dentin-enamel junction (DEJ) compared to the control group. Penicillin at 100 mg/kg also significantly decreased enamel and dentin thickness, impaired their maturation, and led to DEJ flattening. At 50 mg/kg, penicillin did not significantly affect enamel and dentin thickness but still disrupted their development and caused DEJ flattening.

Conclusions

Penicillin at 100 mg/kg adversely affected enamel and dentin development, causing significant defects similar to those caused by tetracycline, although the severity and mechanisms may differ. Even at 50 mg/kg, penicillin disrupted enamel and dentin development, underscoring the clinical relevance of these findings and the need for caution when prescribing penicillin during pregnancy, even at lower doses, due to its potential to disrupt dental development.

Objectives

This in vitro experimental study aimed to evaluate the effects of laboratory contamination of implant abutment screws and connection surfaces on reverse torque values (RTVs), as an indicator of screw preload loss.

Material and Methods

Forty-five Dentis One Q implants and 45 CCM UCLA abutments were randomly assigned into three groups (n = 15 per group). Group 1 (control) involved uncontaminated abutments and screws with no restorations. Group 2 (screw contamination) used new abutments attached with screws contaminated by laboratory materials (porcelain powder, metal debris, and polishing paste). Group 3 (connection contamination) included screw-retained restorations fabricated under contaminated conditions and attached using new screws. All samples were subjected to standardized torque (250 N·cm), thermocycling (1500 cycles between 5°C and 55°C), and subsequent RTV measurement. One-way ANOVA and Tukey's post hoc tests were used for statistical analysis (α = 0.05).

Results

Mean RTVs (SD) were 218 (0.15) N·cm (control), 181 (0.14) N·cm (screw contamination), and 207 (0.11) N·cm (connection contamination). RTVs in the screw contamination group were significantly lower than both the control (p < 0.001) and connection contamination groups (p < 0.001). The difference between the control and connection contamination groups was not statistically significant (p = 0.08).

Conclusions

Laboratory contamination of implant components can significantly reduce reverse torque values, particularly in cases of screw contamination, indicating an increased risk of screw loosening. Contamination control during prosthetic procedures is essential to maintaining implant stability.

Objectives

Among the minimally invasive techniques for treating temporomandibular joint disorders (TMDs) is dry needling, which can be used as a potential treatment method. This study aims to review current knowledge to understand the impact of dry needling on treating TMDs.

Methods

This systematic review was carried out in alignment with the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A comprehensive literature search was performed using PubMed, Scopus, and Google Scholar. The search was done on the studies published between 2000 and 2024. Cochrane Collaboration's Risk of Bias tool for randomized controlled trials (RCTs) was applied to evaluate the risk of bias.

Results

A total of 673 studies were identified. Among these, 245 articles were assessed for eligibility; ultimately, 10 studies were made up of the final review. These studies evaluated several outcome measures, the most common of which were: the visual analog scale (VAS), verbal rating scale (VRS), electromyography (EMG), extent of mouth opening, pain symptomatology, myofascial trigger point pain, sonographic measurements, bilateral muscle palpation with a pressure algometer, Tinnitus Handicap Inventory (THI), and mandibular mobility. Most RCTs had a low risk of bias.

Conclusion

The findings consistently underscore the role of dry needling (DN) and other adjunctive therapies in improving clinical outcomes, particularly pain reduction and functional improvement.

Objectives

This study aimed to evaluate the whitening effect, shear bond strength (SBS), microhardness, and microstructure of discolored resin brackets following whitening treatment with various concentrations of hydrogen peroxide (HP).

Material and Methods

Resin brackets were bonded to the enamel surface and discolored with a curry solution. Control (distilled water; DW) and experimental solutions of 8.7%, 17.5%, and 35% HP were applied to the discolored resin brackets for 15 min. Resin brackets were then stored in DW for a week by repeating this whitening process three times. The whitening efficacy was evaluated according to the ISO 28399:2011. The SBS was measured using a universal testing machine. The microhardness and microstructure of the resin brackets were observed using a microhardness tester and field-emission scanning electron microscopy (FE-SEM). All the results were analyzed using a one-way ANOVA analysis and Tukey's post-hoc test (p = 0.05).

Results

All the experimental groups demonstrated a significant whitening effect on the discolored resin brackets compared to the control group (p < 0.05). Especially, 35% HP showed faster color changes than the other groups (p < 0.05). The microhardness of the resin bracket was significantly lower in 35% HP compared to the control group (p < 0.05). FE-SEM analysis revealed no significant difference between the experimental and control groups.

Conclusions

HP application at concentrations of > 8.7% and < 17.5% is effective in whitening discolored resin brackets while not deteriorating the SBS, surface hardness, and microstructure. Dental clinicians can safely use HP within the recommended range to achieve effective esthetic outcomes without compromising bracket performance and durability.

Objective

Through a scoping review, this study meticulously mapped and characterized these nanostructured clays used to release antibacterial active compounds from direct restorative dental materials.

Material and Methods

The systematic approach involved searches in the PubMed/MEDLINE, Lilacs, Web of Science, Scopus, ScienceDirect, and Embase databases. Two independent and calibrated researchers (kappa: 0.94) performed all systematic steps according to the PRISMA guideline and the Joanna Briggs Institute Scoping Review Methodology Group (JBI) protocol. The reviewers developed a data extraction table to gather key information.

Results

A total of 782 articles were retrieved in the initial search using the specified strategies. After thoroughly reviewing the manuscripts, five were selected following the exclusion of duplicates and application of eligibility criteria. Montmorillonite and halloysite nanotubes emerged as the predominant nanostructured clay. Cetylpyridinium chloride was the most common active agent, notable for its antibacterial properties. Resin-based composites were the most frequently studied direct restorative material for the prevention of recurrent caries.

Conclusion

Although the number of primary studies published in the literature was limited, montmorillonite and halloysite nanotubes appear to be promising nanocarriers for antibacterial active compounds in direct restorative dental materials.

Objectives

This study was performed to identify the characteristics of oral and maxillofacial injuries in children and determine factors influencing a treatment duration of more than 1 month using medical records.

Material and Methods

This retrospective observational study reviewed medical records of 258 children (< 16 years of age) with maxillofacial trauma treated at a university hospital between 2011 and 2021. Patients with and without tooth fractures or dislocations were compared, and the prevalence of injuries was analyzed across three age groups (0–2, 3–5, ≥ 6 years). Long (> 1 month) and short (< 1 month) treatment durations were compared, and independent predictive factors for prolonged treatment were identified.

Results

Tooth injuries were observed in 204 (79.1%) patients. Deciduous central incisors in the primary dentition and central incisors in the permanent dentition were the most commonly affected. Soft tissue injuries occurred in 165 (64.0%) patients, while maxillofacial fractures were present in 7 (2.7%). Tooth fractures significantly increased with age (p < 0.001), while dislocations showed no age-related differences. Logistic regression revealed that maxillofacial fractures, tooth fractures, and two or more dislocated teeth were independent predictors of prolonged treatment, with odds ratios of 14.666 (1.625–132.359), 2.411 (1.099–5.287), and 2.350 (1.208–4.570), respectively.

Conclusions

Maxillofacial fractures, multiple tooth dislocations, and tooth fractures were confirmed as key factors influencing longer treatment durations. These findings may assist in the early management of maxillofacial injuries and improve communication with pediatric patients and their families.

Objectives

This umbrella meta-analysis aimed to answer the clinical question: Do mini-screws and micro-implants improve specific orthodontic outcomes such as intermolar width, interpremolar width, suture expansion, molar movement, and skeletal width compared to conventional anchorage methods?

Materials and Methods

A systematic search was performed in PubMed, Scopus, ISI Web of Science, and Google Scholar up to October 2024. Systematic reviews and meta-analyses on mini-screws and micro-implants in orthodontic treatment were included. Methodological quality was assessed using AMSTAR 2, and a random-effects model was used to calculate effect sizes (ESs) and 95% confidence intervals (CIs). Heterogeneity was evaluated using the I² statistic and Cochrane's Q-test, with subgroup and sensitivity analyses conducted to identify sources of heterogeneity.

Results

Eleven meta-analyses comprising 50 data sets were included. The results indicated that mini-screws significantly increased intermolar width (ES: 2.61 mm, 95% CI: 0.29–4.92, p = 0.02) and skeletal width (ES: 3.33 mm, 95% CI: 1.37–5.29, p = 0.001). However, no significant impact was found on interpremolar width or alveolar width before and after MARPE. Micro-implants significantly reduced molar movement (ES: −1.13 mm, 95% CI: −1.99 to −0.26, p = 0.01). Substantial heterogeneity was noted across several outcomes (I² > 50%), which persisted despite subgroup analyses.

Conclusion

Mini-screws and micro-implants enhance skeletal and intermolar width and control molar movement in orthodontic treatment. However, their effects on other outcomes are inconsistent, warranting further high-quality studies to strengthen clinical recommendations.

Trial Registration: PROSPERRO (CRD42023447137).

Objectives

Due to ozonated water's antimicrobial and anti-inflammatory properties, it may be used as a supplementary treatment to scaling and root planing (SRP). The present study aimed to evaluate the clinical effectiveness of using ozonated water instead of tap water during the SRP for people with chronic generalized periodontitis.

Material and Methods

This randomized clinical trial was conducted on 30 patients with generalized periodontitis Stages I and II, randomly allocated to two groups. Test sites were subjected to ozonated water, and control sites were subjected to tap water. The clinical periodontal parameters were measured at baseline, the 4th, and 8th week of treatment.

Results

Findings showed a significant decrease in periodontal pocket depth (PPD), clinical attachment level (CAL), and gingival index (GI) at both the 4th and the 8th week of treatment in both groups. PPD was further reduced in the test group, but the difference between the two groups was not significant. However, the greater reduction of CAL at the 4th and 8th week (p < 0.001 and p < 0.001, respectively) and also the greater reduction of GI at the 4th week (p = 0.01) was observed in the test group.

Conclusions

Both the test and control groups showed clinical improvement following nonsurgical periodontal therapy. The ozonated water group demonstrated significantly greater reductions in CAL at the 4th and 8th weeks, and in GI at the 4th week. However, the magnitude of these differences was modest and may have limited clinical relevance. Further research is needed to confirm long-term outcomes.