Dental Research Journal最新文献

The integration of computer-aided design (CAD) and computer-aided manufacturing (CAM) technology has significantly transformed restorative dentistry. This review explores the game-changing influence of CAD/CAM systems in restorative dentistry, emphasizing the clinical performance, mechanical attributes, and esthetic potential of contemporary materials such as zirconia, lithium disilicate, polyetheretherketone, polymethylmethacrylate, and advanced resin composites.This systematic review, conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and structured using the PICO framework, comprehensively explored evidence on CAD/CAM dental materials. A thorough search of PubMed, Scopus, Cochrane Library, Web of Science, and Google Scholar (2015-2025) initially identified 1300 records. After rigorous screening and eligibility assessment, studies addressing clinical indications, mechanical performance, and material-specific outcomes of CAD/CAM restorations were included for qualitative synthesis. Lithium disilicate and zirconia emerged as frontrunners in fracture resistance, marginal adaptation, and long-term esthetics. Glass-ceramics and nanohybrid composites demonstrated high performance in posterior and veneer applications. Comparative trials favored CAD/CAM over conventional restorations in precision, fit, and durability. Risk-of-bias assessment indicated predominantly low bias across key domains, ensuring reliability of findings. CAD/CAM materials combine digital precision with clinical excellence, offering strong mechanical performance and refined esthetics for optimal functional outcomes. Clinical evidence highlights their accuracy, efficiency, and long-term success compared to traditional restorative techniques.

Background: Chronic periodontitis is an infectious disease of the oral cavity that causes progressive destruction of periodontal tissues, leading to structural changes like attachment loss, bone resorption, resulting in bony defects, and potential tooth loss if left untreated. Effective drugs, such as alendronate, rosuvastatin (RSV), atorvastatin, melatonin, and metformin (MF), have been used as adjuncts to scaling and root planning and require evaluation for their comparative effectiveness in treating bony defects in patients with chronic periodontitis. This study aims to compare the effectiveness of these drugs for treating such defects.

Materials and methods: This network meta-analysis (NMA) was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and registered in PROSPERO (CRD42024600432). A comprehensive search of PubMed, Scopus, and Cochrane Library identified 11 eligible randomized clinical trials reporting changes in clinical attachment level (CAL) and bone fill (BF) at 6 months posttreatment. The NMA systematically compared treatment outcomes across different intervention groups.

Results: MF was the most effective treatment for CAL and BF at 6 months. Ranking probabilities indicated that MF and RSV had the highest likelihood of being the most effective treatments.

Conclusion: These findings from the NMA suggest that MF may be an effective option for CAL improvement and BF. Further research is needed to validate these results and optimize treatment strategies for bony defects in chronic periodontitis.

Background: Dentin hypersensitivity (DH) is a prevalent clinical condition, occurring when exposed dentin reacts to various thermal, chemical, or mechanical stimuli. Although different interventions such as fluoride varnish, adhesives, and natural bioactive compounds have been tested, there is still a demand for more effective and durable solutions.This study aimed to evaluate the ability of a nanoemulsion containing Nigella sativa nanoparticles encapsulated in propolis nanomicelles to occlude dentinal tubules and to compare its performance with fluoride varnish under the simulated acidic and mechanical challenges.

Materials and methods: In this in vitro study, hydroethanolic extract of Nigella sativa was encapsulated in propolis-based micelles to prepare the nanoemulsion. Thirty-six extracted human third molars were sectioned at the mid-crown and randomly assigned to four groups (n = 9): (1) normal saline, (2) nanoemulsion (15-min immersion), (3) nanoemulsion (30-min immersion), and (4) 5% fluoride varnish. Each group was further divided into three subgroups: control (no challenge), acid challenge, and simulated toothbrushing. Scanning electron microscopy at × 4000 magnification was used to quantify the percentage of occluded dentinal tubules. Data were analyzed with the two-way analysis of variance and least significant difference post hoc tests at a significance level of P ≤ 0.05.

Results: Material type (P = 0.018), challenge regimen (P < 0.001), and their interaction (P < 0.001) significantly influenced occlusion percentage. The highest occlusion was observed with nanoemulsion (30-min immersion) in the acid challenge subgroup (46.78%), followed by nanoemulsion (15-min immersion) after toothbrushing (41.85%), and fluoride varnish in the acid challenge subgroup (37.19%). Acidic and brushing challenges significantly reduced occlusion in all groups (P < 0.001).

Conclusion: Nanoemulsion containing Nigella sativa nanoparticles within propolis nanomicelles demonstrated superior dentinal tubule occlusion compared to fluoride varnish, with notable resistance to acid and brushing challenges. Given their natural origin, anti-inflammatory, and remineralizing properties, such nanoformulations may offer an effective and biocompatible alternative for managing DH. Clinical studies are recommended to validate these findings in vivo.

Background: Accelerating orthodontic space closure while minimizing anchorage loss remains a clinical priority. Micro-osteoperforation (MOP) has emerged as a minimally invasive technique to enhance tooth movement. This study aimed to compare the effectiveness of two MOP protocols on the rate and pattern of maxillary extraction space closure.

Materials and methods: In this parallel three-arm randomized controlled trial, 30 patients (17-30 years) with 3-4 mm of residual maxillary extraction space were randomly assigned to MOP1, MOP2, or control groups (n = 10 each). All underwent space closure using 0.019" × 0.025" stainless steel archwires and 150 g NiTi closed coil springs. MOP1 involved four perforations (two buccal, two palatal) at the extraction site center; MOP2 included additional perforations mesial and distal to the first molar. MOPs were performed monthly for 3 months. Primary outcome was space closure rate assessed via monthly three-dimensional intraoral scans. Secondary outcomes included angular tipping (PA radiographs) and relative anterior/posterior tooth movement. Statistical analysis used ANOVA, Kruskal-Wallis, and nonparametric post hoc tests (P < 0.05).

Results: Thirty patients (11 males, 19 females) were equally divided into MOP1, MOP2, and control groups. After 3 months, mean space closure was 0.88 mm greater in MOP1 and 0.90 mm greater in MOP2 compared to control. The 0.02 mm difference between MOP1 and MOP2 was clinically negligible. Control showed the greatest tipping, whereas MOP2 had the least. No adverse events were observed.

Conclusion: Monthly application of MOP significantly accelerates space closure and reduces tipping without increasing anchorage loss. The difference between MOP protocols was minimal and clinically negligible.

Background: This study aimed to histopathologically compare the efficacy of 5% melatonin (MEL) gel and 1.2% rosuvastatin (RSV) gel on bone regeneration in rat calvarial defects.

Materials and methods: In this animal study, 8-mm defects were created in the calvaria of 24 adult male Wistar rats weighing 200 g. The rats were randomly assigned to three groups (n = 8). The defects were filled with placebo gel (methylcellulose with no active ingredient) in Group I, 5% MEL gel in Group II, and 1.2% RSV gel in Group III. The rats were sacrificed after 4 weeks. Hematoxylin and eosin (H and E) staining was used to prepare histological sections. Statistical analysis was performed using the ANOVA and Tukey tests (α =0.05).

Results: Osteogenesis was significantly higher in the MEL and RSV groups than in the control group (P < 0.05). However, the difference between the MEL and RSV groups was not significant (P > 0.05).

Conclusion: Osteogenesis was significantly higher in the MEL and RSV groups than in the control group (P < 0.05). Local administration of MEL and RSV can be used as a stimulant of bone formation. However, more investigations are required to evaluate the bone regeneration capacity of MEL and RSV gels.

Background: This study aimed to synthesize mesoporous zinc oxide nanoparticles (ZnO NPs) and evaluate their effect as dentin pretreatments on the microshear bond strength (μSBS) of a universal adhesive.

Materials and methods: This in vitro experimental study used 100 extracted human molars sectioned to expose mid-coronal dentin. Samples were divided into five groups (n = 20) based on pretreatment: no treatment, chlorhexidine (CHX), calcined mesoporous ZnO NPs, noncalcined mesoporous ZnO NPs, and ZnO NPs. Each group was subdivided into two subgroups (n = 10) based on the universal adhesive application mode: etch-and-rinse (E and R) or self-etch (SE). Pretreatments were applied for 1 min. Composite resin was bonded using a universal adhesive. After 24 h of storage in distilled water at 37°C, μSBS testing was performed. Statistical analysis included the Shapiro-Wilk test for normality, two-way analysis of variance with Tukey's post hoc test, and t-tests, with significance set at P < 0.05.

Results: The noncalcined mesoporous ZnO NP group showed the highest μSBS, followed by the ZnO NP group, with significant differences compared to other groups (P < 0.05). Lower μSBS values were observed in the calcined mesoporous ZnO NP, CHX, and untreated groups. The adhesive application mode had a significant effect only in the untreated and calcined mesoporous ZnO NP groups (P < 0.05), with SE yielding higher μSBS than E and R.

Conclusion: Noncalcined mesoporous ZnO NPs enhanced dentin bond strength more effectively than other pretreatments, including CHX, indicating their potential as a promising alternative in adhesive dentistry.

Background: This study assessed the linear accuracy of three-dimensionally (3D)-printed mandibular models from cone-beam computed tomography (CBCT) scans with two voxel sizes.

Materials and methods: In this in vitro study, five dry human mandibles underwent CBCT with 0.2- and 0.3-mm voxel sizes. The images were converted to STL format, and the distances between (I) mental foramen (MF) and alveolar ridge crest, (II) MF and inferior border of the mandible (IBM), and (III) alveolar crest and IBM at the midline, as well as the (IV) left central incisor socket depth, (V) left second premolar buccolingual socket width, and (VI) right third molar buccolingual socket width were measured on the CBCT scans, 3D-printed models, and dry mandibles. Two observers recorded the measurements twice, 1 week apart. We analyzed the data using the intraclass correlation coefficient and Pearson's correlation test. Statistical significance was set at P < 0.05.

Results: Since the interobserver agreement was high, the mean data was used for the comparisons. The linear accuracy was high for MF-IBM, MF-alveolar crest, and alveolar crest-IBM distances, and second premolar and third molar buccolingual socket width. CBCT scans demonstrated reliable accuracy for left central incisor socket depth measurement, but a lack of significant correlation was found between the 3D-printing and gold-standard measurements of this variable.

Conclusion: The linear accuracy of CBCT scans taken with 0.3- and 0.2-mm voxel sizes was comparable, and they may be used for the fabrication of linearly accurate 3D-printed models of mandible. 3D-printed models demonstrated high precision in all measured parameters except socket depth.

During endodontic practice, a practitioner may encounter iatrogenic errors that are unpleasant and affect the outcome. One common iatrogenic error that can occur during dental treatments is instrument separation. This issue can significantly hinder the disinfection of the root canal system. The clinician must evaluate the treatment alternatives of orthograde or surgical retrieval the separated instrument or bypassing it and sealing the fragment within the root canal space. One method for managing a separated instrument is the loop technique. This case series reports four cases of successful retrieval of separated instruments using the loop technique, which is a reliable, effective, and safe method for file retrieval. It also provides a rapid review of the relevant literature.

Background: Bone remodeling is essential for orthodontic tooth movement. Techniques such as micro-osteoperforation (MOP) and vibration have been introduced to accelerate treatment by stimulating biological responses.

Materials and methods: Randomized clinical trial study adult orthodontic patients who required bilateral extraction of maxillary first premolars were randomly assigned to two groups (n = 10) of intervention and control. Both groups received MOP at the onset of canine retraction. The intervention group also used a VPro5 vibrator for 28 days after the onset of canine retraction in addition to MOP. GCF samples were collected before the onset of orthodontic treatment (T0), right before canine retraction (T1), and after 24 h (T2), 7 days (T3), and 28 days (T4) by a paper point, and the GCF levels interleukin (IL)-1 B, receptor activator of nuclear factor kappa-B ligand (RANKL), C-C motif chemokine ligand (CCL) 2, and tumor necrosis factor-alpha (TNF)-α were measured. Data were analyzed using SPSS v25. Repeatedmeasures Analysis of Variance was employed to compare quantitative outcomes between groups and over time, with statistical significance set at P < 0.05.

Results: The GCF level of the four inflammatory factors was not significantly different between the two groups at any time point (P > 0.05). The trend of change in GCF level of the four inflammatory factors was also the same in the two groups over time, such that the lowest level of all four markers was recorded at T0. The highest level of TNF-α was recorded at T2, and the highest level of RANKL, IL1-B, and CCL2 was recorded at T2 and T3.

Conclusion: It does not seem that combined MOP with vibration can increase the level of inflammatory factors in GCF.

Background: The aim of this study was to compare oropharyngeal airway measurements among high- and low-risk individuals for obstructive sleep apnea syndrome.

Materials and methods: In this cross-sectional study on patients referred for cone-beam computed tomography (CBCT) imaging before dental implant surgery, inclusion criteria were individuals aged >30 years, Class I occlusion, without anomalies of the head and neck, dentulous individuals, systemically healthy, and without defects in the airways. The exclusion criteria were individuals whose responses to the study questionnaires did not match that of their companions and images with artifacts. These patients and their relatives/housemates were requested to fill in the Epworth Sleepiness Scale and Berlin questionnaires. Based on the answers, the patients were classified as high-risk groups, and patients formed low-risk groups. CBCT images were obtained with 85 kVp and 35 mAs and analyzed using ITK-Snap and Mimics. Oropharyngeal airway volume, minimum cross-sectional area, both mesiodistal and anterior-posterior distances in the same axial cut, and linear length between the posterior pharyngeal wall and nasal spine/soft palate/tongue on the midsagittal slice were measured. The level of significance was considered 0.05 for the independent samples t-test and Chi-square test. Pearson's correlation coefficient was chosen to discover correlations between CBCT measurements and patients' age, body mass index (BMI), and neck circumference.

Results: In total, 32 individuals participated with a mean age of 50.2 and 53.2 years in the high-risk and low-risk groups, respectively. Ten females and six males comprised the high-risk group, and eight females and eight males formed the low-risk group. Higher BMI and neck circumference existed in the high-risk group, and they both showed a direct relationship with the Epworth score. Oropharyngeal measurements presented significant differences between the two groups, except for the distance between the base of the tongue and the posterior pharyngeal wall (P = 0.86).

Conclusion: Oropharyngeal airway volume and minimal cross-sectional area can be used as a predictor for obstructive sleep apnea, and CBCT imaging is beneficial for this purpose.