Dental Research Journal最新文献

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.

Zirconia abutments can enhance esthetics by providing a natural appearance due to their semitranslucency. Evidence for final outcomes of using zirconia abutments compared to other available materials are diverse. This study aims to review all available evidence from previous reviews to compare zirconia and titanium abutments regarding biological, mechanical, and esthetics indices and survival. An electronic search was conducted on six databases (PubMed, Scopus, Embase, Web of Science, ProQuest, and Cochrane) for systematic reviews/meta-analyses published until 2023. The relevant data were extracted and reviewed from the selected studies. Fourteen articles were included following a systematic application of the inclusion and exclusion criteria. These studies evaluated various factors, including soft tissue recession, width of keratinized mucosa, papilla index, plaque accumulation, Copenhagen Index Score, Implant Crown Aesthetic Index, gingival discoloration, pocket probing depth, marginal bone loss, bleeding on probing, Pink Esthetic Score, White Esthetic Score, survival rate, and patient's satisfaction. Zirconia abutments showed better or similar effects than titanium in biological, esthetic, and mechanical factors and survival.

Background: Studying pathology is not a fascinating subject for many students. Today, novel educational methods have received attention worldwide. This study aimed to design an oral and maxillofacial pathology learning application and evaluate its effectiveness on dental students' knowledge of the Isfahan dental faculty.

Materials and methods: In this experimental study, after designing a web application, including an oral pathology context (PathoGAME), its effectiveness on 112 junior dental students' knowledge was investigated in 2022. After introducing the application, students were motivated to use the app for learning oral pathology. They were then examined in the midterm and final examinations. Subsequently, their scores on the questions related to the application's contents were compared with the scores of other questions. Finally, students' satisfaction with the application was evaluated. The data were analyzed using SPSS software and paired t-tests, Pearson's tests, and analysis of variance.

Results: In the midterm examination, there was no significant difference between the mean score of questions related or unrelated to the application's content among those who had used the application. Furthermore, the mean scores of the related questions for the application users and those who did not, were not significantly different (P = 0.5). However, on the final examination, the mean score for questions related to the application was significantly greater for students who used the application than for those who did not (P = 0.03).

Conclusion: Overall, novel educational methods, such as this application, were beneficial for improving students' understanding of pathology. The users' satisfaction was high in utilizing this application, indicating the application's success and confirming its feasibility.

Background: Immediate loading (IL) offers patients the advantage of reduced treatment time by immediate prosthesis placement or 48 h after implantation. Non-IL (NIL), on the other hand, involves a recovery period to allow osseointegration. Both methods are widely used, but their long-term effectiveness remains controversial. This study provides an umbrella review of long-term clinical outcomes of immediate and NIL protocols in single-implant restorations. This review combines and analyzes the findings of several systematic reviews and meta-analyses to evaluate implant survival rate, bone stability, peri-implant soft-tissue health, and complications associated with each approach.

Materials and methods: Systematic reviews and meta-analyses published in the past two decades were evaluated, and studies comparing immediate and NIL protocols with follow-up periods of at least 6 months were included in this comprehensive review. Using key terms such as "immediate loading" OR "nonimmediate loading" OR "delay loading" AND "single-implant restoration" * " OR "tooth implant*" OR "Dental Implant*," valid national and international databases such as PubMed, Scopus, and Cochrane Library were searched to achieve the objectives of the study. After screening the retrieved studies, information about the implant survival rate, marginal bone loss, peri-implant soft tissue health, and prosthetic complications were extracted.

Results: Immediate and NIL protocols showed a high long-term implant survival rate, varying between 92% and 98%. IL showed a slightly higher rate of marginal bone loss than NIL, especially in the 1^st year after implant placement. However, peri-implant soft tissue health and overall patient satisfaction were similar in both protocols. Moreover, IL can be equally successful in cases where high initial implant stability is achieved. Yet, NIL remains the preferred choice in patients with compromised bone quality or high-risk conditions.

Conclusion: Our research demonstrates that both immediate and NIL protocols offer high long-term implant survival rates (92% to 98%). While IL shows a slightly higher rate of marginal bone loss, particularly in the 1^st year, it remains a viable option in cases with high initial implant stability. Peri-implant soft-tissue health and patient satisfaction were similar for both protocols. NIL continues to be the preferred approach for patients with compromised bone quality or high-risk conditions. These findings emphasize the importance of individualizing treatment plans based on implant stability and patient-specific factors to optimize outcomes in single-implant restorations.

Background: Accurate and early diagnosis of dysplastic lesions is crucial for successful treatment. A decrease in E-cadherin expression has been observed in dysplastic lesions and tumors. Therefore, the aim of this study was to investigate the expression of E-cadherin, a cell membrane adhesive protein involved in tissue structure and differentiation, in oral reticular lichen planus, erosive lichen planus, and lichenoid lesions.

Materials and methods: This descriptive cross-sectional study was conducted on 65 oral samples (20 reticular lichen planus, 20 erosive lichen planus, and 20 lichenoid lesions, with 5 samples of healthy mucosa), to evaluate the expression of E-cadherin using immunohistochemical methods. Data were analyzed using SPSS software (version 25), descriptive statistics, Chi-square tests, and Fisher's exact tests, with a significance threshold set at P < 0.05.

Results: The majority of patients were female (72.3%) and primarily in the sixth and seventh decades of life (49.2%). A significant difference was observed between the studied groups regarding staining status (P = 0.038), with erosive lichen planus showing the highest frequency of alterations in E-cadherin expression (45%). In addition, a significant difference was noted between staining status and lesion location (P = 0.004), with the highest frequency of E-cadherin expression changes occurring in buccal mucosal samples (30%).

Conclusion: E-cadherin expression in erosive lichen planus is significantly lower than in healthy tissue, reticular lichen planus, and lichenoid lesions. Given the similar reduction observed in squamous cell carcinoma samples, evaluating E-cadherin expression may aid in the early recognition of malignant changes.

Background: Plaque control is one of the main issues after crown lengthening surgery. It is advised to use mouthwashes since mechanical plaque control is not possible due to the presence of the wound. Thus, the present study aims to compare the effectiveness of Persica and Protact mouthwash on gingival healing after crown lengthening surgery.

Materials and methods: In this double-blind clinical trial, 33 candidates were randomly divided into three groups (n = 11). The first group used 0.2% chlorhexidine (CHX) mouthwash; the second group used Persica mouthwash; and the third group used Protact mouthwash. Patients were followed for 14 days and changes in their plaque index (PI), gingival index (GI), stain index (SI), tongue taste, and color were recorded. Data were analyzed using SPSS V.22 using the Kruskal-Wallis, Wilcoxon, and Chi-square tests. The significance level was considered to be < 0.05.

Results: The PI decreases significantly after 14 days in the CHX group (P = 0.011), however, this difference was not significant in the other two groups. Moreover, the GI and SI were not significantly different in any of the groups (P > 0.05). The changes in the tongue color and taste were only observed in the CHX group and patient dissatisfaction was higher in this group.

Conclusion: CHX is the gold standard for patients who have undergone clinical crown lengthening surgery; nevertheless, considering its side effects and bad taste, Persica and Protact herbal mouthwashes can be used in more sensitive and uncooperative individuals.