Nanodentistry is an emerging field of nanotechnology in order to improvement dental treatment, care and prevention of oral diseases.

Background:Due to increasing demands for a full mouth implant reconstructions and the fact that the most failures are associated with biomechanical complications, determining the effect of different occlusal patterns on these complications seems inevitable. The aim of this study is to compare affection of different occlusal designs in full mouth implant reconstructed patients on electromyographic activity of temporal and masseter muscles compared to natural dentition.Methods:Thirty-two patients were included in this study, considering that 16 patients had natural dentition and the other 16 were full mouth implant reconstruction patients. In both groups, the participants were divided into two subgroups: 8 patients had canine guidance occlusal pattern and the other eight had a group function occlusal pattern. Muscle contractions were studied during both maximum intercuspation and lateral excursions to the point of intercanine contact using an electromyography device.Results:The average percentages of masseter muscle contraction in lateral excursions relative to maximum intercuspation were as follows: 72.20% in full mouth implant reconstruction patients with group function occlusion 69.49% in natural dentition with group function occlusion 58.85% in full mouth implant reconstruction patients with canine guidance occlusion 30.91% in natural dentition with canine guidance occlusion. The average percentages of temporal muscle contraction in lateral excursions relative to maximum intercuspation were as follows: 70.87% in full mouth implant reconstruction patients with group function occlusion 78.57% in natural dentition with group function occlusion 51.99% in full mouth implant reconstruction patients with canine guidance occlusion 31.55% in natural dentition with canine guidance occlusion.Conclusion:A canine guidance occlusal pattern in both, natural dentition and full mouth implant-supported FDP, patients resulted in decreased muscle contraction. This decreasing is more significant in natural dentition and it is better to establish a canine guided occlusion in a full mouth reconstruction patient.

Background: Learning style is a factor influencing academic achievement. There are contradictory results in studies on the relationship between learning styles and academic achievement. The current study aimed at investigating the relationship between learning styles and academic achievement in dental students. Methods: In the current descriptive-analytical study, 184 dental students were selected by simple random sampling. The VARK questionnaire was used as the data collection tool. The grade point average (GPA) of previous semester was used as an indicator of academic achievement, and accordingly, students were divided into two groups of strong (GPA ≥15) and weak (GPA ≤14.99). Results: The most common learning styles in strong students were unimodal (n = 55, 42%) and bimodal (n = 41, 31.3%), while they were unimodal (n = 28, 47.2%) and bimodal (n = 24, 45.3%) in the weak students. There was no significant relationship between learning styles and academic achievement in the two groups of strong and weak students. Conclusion: No significant relationship was found between learning style and academic achievement. Further studies with larger sample sizes are recommended. Further studies with larger sample sizes are recommended.

Background:Oral lichen planus (OLP) is associated with various other systemic conditions such as hypertension, diabetes mellitus (DM). This study evaluated the prevalence of OLP in DM patients compared with non-diabetic control subjects in a meta-analysis study.Methods:In this study from January 1973 to August 2016, we searched the studies in Web of Science, Medline/PubMed, Scopus, Science direct, SID (Scientific Information Database), Cochrane and Embase databases. Strategy search was the Medical Subject Heading (MeSH) term oral lichen planus or oral mucosa combined with diabetes in PubMed and this search in other databases. Heterogeneity between estimates was evaluated by the Q and I2 statistic. Also, publication bias was assessed through funnel plot analysis with the Kendall’s and Egger’s tests.Results:From 831 studies were identified with different search strategies, 11 studies met the criteria to be included in meta-analysis (11 case-control studies). The overall prevalence of OLP in 11 studies with 4937 DM patients and 3698 control subjectswas 1.5% and 0.75%, respectively. In this meta-analysis, the OR in prevalence of OLP in DM patients compared with control subjects was 1.584 (95%CI1.013-2.477; P=0.044) with a low level of heterogeneity (I2 = 0%) that the result showed the prevalence of OLP in DM patients is significantly more than control subjects.Conclusions:This meta-analysis study showed an association between OLP with DM, whereas this association was no significant in previous studies, it was probably because different selecting of age, sex, type of DM, medications and criteria. Totally, the meta-analysis showed the risk of OLP in DM was higher compared with control subjects.

Interleukin-6 (IL-6) is a cytokine that contributes to the pathogenesis of oral lichen planus (OLP). The aim of this meta-analysis study is the evaluation of IL-6 levels in the serum and saliva of patients with OLP compared with healthy controls. We searched the studies in 5 databases: PubMed/Medline, Scopus, ScienceDirect, Web of Science, and Cochrane Library, from 1983 to Oct 31, 2016. Eleven studies were analysed for the meta-analysis study. The reviewers independently evaluated the quality of each included study using the Newcastle-Ottawa Quality Assessment Scale (NOS). A random-effects meta-analysis, using Comprehensive Meta-Analysis software version 2.0, was used to reflect the variation in studies. Heterogeneity between estimates was evaluated by the Q and I2 statistics and for the Q statistic; heterogeneity was considered for p < 0.1. Eleven studies included 529 OLP patients and 333 healthy controls. The review identified two different biomaterials used for IL-6 assays: saliva and serum. The mean quality score of eleven studies was 7 (high quality). Estimates pooled from 6 studies showed significant high saliva IL-6 levels in OLP patients compared with healthy controls (the standardised difference in means (SDM) = 4.534, 95% CI = 1.915-7.153, p = 0.001). Also, estimates pooled from 7 studies showed significantly high serum IL-6 levels in OLP patients compared with healthy controls (SDM = 1.482, 95% CI = 0.524-2.439, p = 0.002). The higher levels of IL-6 in saliva compared with serum suggest that measurement of this marker in saliva may be more useful than serum for diagnostic and therapeutic aims.

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As high as 20% of the population is thought to have recurrent aphthous stomatitis (RAS), hence, finding new therapeutic agents may be needed. Pomegranate (Punica granatum), has been extensively used in the folk medicine of many cultures, as it possesses antioxidant, anti-inflammatory and anti-bacterial properties. In this study, it is hypothesized that a topical form of pomegranate peel extract (PPE) may shorten the duration, accelerate the healing and reduce the pain of RAS patients. The presented randomized, double-blind study was conducted on 56 patients. Herein, 28 patients were advised to apply PPE gel, and the other 28 patients were given placebo gel, twice daily for one week. Efficacy evaluations were made at days 0 (before using the gel), 3, 5 and 7. The mean values of ulcer size, pain and healing duration of ulcers were compared in both groups. PPE gel was significantly effective in reducing the pain (p<0.001), ulcer size (p<0.001), and healing duration of ulcers (p<0.001) over a period of one week. PPE in the form of oral gel can be used in the management of aphthous ulcers.

There is increasing interest in the use of polyether ether ketone (PEEK) for orthopedic and dental implant applications due to its elastic modulus (close to that of bone), biocompatibility and radiolucent properties. However, PEEK is still categorized as bioinert owing to its low integration with surrounding tissues. Methods such as depositing hydroxyapatite (HA) onto the PEEK surface could increase its bioactivity. However, depositing HA without damaging the PEEK substrate is still required further investigation. Friction stir processing is a solid-state processing method that is widely used for composite substrate fabrication. In this study, a pinless tool was used to fabricate a HA/PEEK surface nanocomposite for orthopedic and dental applications. Microscopical images of the modified substrate confirmed homogenous distribution of the HA on the surface of the PEEK. The resultant HA/PEEK surface nanocomposites demonstrated improved surface hydrophilicity coupled with better apatite formation capacity (as shown in the simulated body fluid) in comparison to the pristine PEEK, making the newly developed material more suitable for biomedical application. This surface deposition method that is carried out at low temperature would not damage the PEEK substrate and thus could be a good alternative for existing commercial methods for PEEK surface modification.