The Impact of Plasma Treatment of Cercon® Zirconia Ceramics on Adhesion to Resin Composite Cements and Surface Properties

Background: In recent years, the use of Ceramic base zirconia is considered because of chemical stability, biocompatibility, good compressive and flexural strength in dentistry for all ceramic restorations. However, due to its chemical stability, there is a challenge with dental bonding. Several studies have done to improving zirconia bonding but they are not reliable. Purpose of this research is a study of effect of plasma on bonding strength Zirconia.  Methods: In this research zirconia blocks' surfaces polished with 1200grit sandpaper. Samples were processed with plasma of oxygen, argon, air and oxygen-argon combination with 90-10 and 80-20 ratio.  Surface modifications were evaluated by contact angle, surface roughness, and topographical assessments. Cylindrical Panavia f2 resin-cement and Diafill were used for micro shear strength bond measurements. The data analysis was performed by SPSS 20.0 software and one-way analysis of variance. Results: The results showed that plasma can increase micro cutting bond strength, decrease surface roughness, increase surface activation energy. Maximum cutting bond strength by using Panavia f2 cement, is for air and argon plasma, and by using margin bond and Diafill composition cement, is for air and combination of oxygen and argon with 20-80 ratio.  Conclusion: According to this research plasmatic processing with dielectric barrier method in atmospheric pressure can increase Zirconia bonding strength

Evaluation of association between polymorphisms in IL17A, IL17F and IL2 genes and chronic periodontal disease in some health care centers, north Tehran, 2015-2016

زمینه و اهداف: بیماری‌های پریودنتال بخش عظیمی از بیماری‌های دهانی مطرح برای سازمان بهداشت جهانی را شامل می‌شوند. مطالعات بسیاری نشان می‌دهد که ژنتیک نقش بسیار مهمی را برروی پیشرفت و شدت بیماریهای پریودنتال دارد. هدف این مطالعه مقایسه پلی‌مورفیسم ژن  اینترلوکین 17 در بیماران مبتلا به پریودنتیت مزمن و افراد سالم در جمعیت ایرانی است. مواد و روش‌ﻫﺎ: 99 بیمار مبتلا به بیماری پریودنتال مزمن به همراه 75 نفر که از نظر پریودنتال سالم و یا مبتلا به ژنژیویت بودند، به وسیله پارامترهای کلینیکی (CAL , BOP , PD , GI) به عنوان جمعیت مورد مطالعه انتخاب و به 4 گروه تقسیم شدند. سپس از کل جمعیت 3 سی‌سی نمونه خون محیطی جمع آوری شد. پس از استخراج دی ان ای نمونه‌های جمع آوری شده در دمای ºC 80-  منجمد شدند تا در نهایت تعیین ژنوتایپ توسط آبشار آنزیمی پلیمراز صورت گرفت. در کلیه مراحل انجام پژوهش، موازین اخلاقی مراعات گردید و رضایت آگاهانه از تمامی داوطلبین اخذ گردید. یافته‌ها: بین پلی‌مورفیسم ژنوتایپهای مختلف ژن اینترلوکین 17 و پریودنتیت در جمعیت مورد مطالعه هیچگونه رابطه معناداری یافت نشد. همچنین در مقایسه‌های گروه بندی شده نیز اختلاف از نظر آماری معنادار نبود (P>0.05). نتیجه‌گیری: در نهایت این مطالعه نشان داد که بین هیچ یک از ژنوتایپها و پریودنتیت مزمن در جمعیت ایرانی مورد بررسی، ارتباط وجود ندارد و برای یافتن نتایج قابل تعمیم به جمعیت ایرانی نیاز به مطالعات گسترده‌تری در آینده می‌باشد.Background and Aims: Periodontal diseases encompass a wide range of oral diseases in which world health organization concerns about them. The literature already includes several reports of genetics leading role in the development and intensity of periodontal diseases. The purpose of the present study was to investigate the association between IL-17A,F gene polymorphisms and susceptibility to chronic periodontitis in an Iranian population.Material and Methods: Totally 99 patients with chronic periodontal disease and 75 healthy periodontal cases or those with gingivitis were selected through clinical factors (GI, PD, BOP, CAL), as the studypopulation. They were then divided into four groups and 3mL peripheral blood sample were collected.Total DNA was extracted from samples and extracted DNA was stored at -80°C until genotyping and polymorphisms detection using restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR). Ethical issues were all considered. Informed consent was obtained from all volunteers before the study began.Results: Our data of IL-17 polymorphisms did not show a significant difference amongst study groups (p>0.05).Conclusion: We did not find statistically significant differences between study groups in Iranian population. Stratification analysis based on the severity of the chronic periodontitis indeed declared no significantdifference in relation to genotype distribution and allelic polymorphisms frequencies

Nonsurgical Management of a Large Periapical Lesion: A Case Report

This case report describes the non-surgical management of a large cyst-like periapical lesion in the mandible of a 16-year-old female with the chief complaint of periodic swelling and pus drainage from the mandibular anterior region gingivae with no history of pain and traumatic accident in this area. Both mandibular central incisors had extensive caries. Root canals of both mandibular central incisors were filled with calcium hydroxide. After 10 days, endodontic therapy was carried out on both teeth. Clinical and radiographic re-evaluations at 3 and 12 months revealed progressing bone healing. This case report shows that appropriate diagnosis in combination with root canal treatment as a conservative non-surgical approach can lead to complete healing of large lesions without invasive treatments.Keywords: Mandibular Incisor; Nonsurgical Endodontic Therapy; Radicular Cys

Assessment of Bacterial Contamination of the External Surface of Anesthetic Cartridges

Objective: Infection control is one of the important aspects in dentistry. Oral and maxillofacial surgery is one of the most sensitive fields in dentistry in which infection control is important; a  sterile surgical set is imperative. Manufacturers only guarantee the sterility of the anesthetic not the sterility of its outer surface. They recommend alcohol to sterile the outer surface (especially the diaphragm) of the cartridge. On the other hand, studies showed contamination of external surfaces in anesthetic cartridges in various amounts. Evaluation of possible microbial contamination of anesthetic cartridge surfaces was the intent of this study.Methods: During this descriptive experimental study, random sampling was performed and 1,200 Iranian and imported cartridges were transferred to different culture media (aerobic, anaerobic and fungal). After 24-48 hours of incubation, samples were transferred to specific culture media. Cultured bacteria were stained, using the Gram staining method. The study was carried out in a 6- month period.Results: We found 6.3 percent of aerobic cultures, 1.8 percent of anaerobic cultures and 0.7 percent of fungal cultures were contaminated by different types of microorganisms sampled from cartridges. Conclusion: The contamination of cartridges is not ignorable and placing them directly in the sterile surgical set is not recommended

Root Canal Morphology of Permanent Mandibular Premolars in Iranian Population: A Systematic Review

Introduction: It is essential for clinicians to have knowledge about root canal configuration, although its morphology varies largely in different ethnicities and even in different individuals within the same ethnic group. The current study reviewed the root canal configuration of root canals in mandibular first and second premolars among Iranian population based on independent epidemiological studies. Methods and Materials: A comprehensive search was conducted on retrieved articles related to root canal configuration and prevalence of each types of root canal in mandibular premolars based on Vertucci’s classification. An electronic search was conducted in Medline, Scopus and Google Scholar from January 1984 to September 2015. Results: In eleven studies conducted in eight provinces, 1644 mandibular first premolars and 1268 second premolars were investigated. Within mandibular first premolars, 70.9% were Vertucci's type I, followed by 10.4% type III, 7.18% type IV, 5.23% type II and 5.16% type V. In addition, among mandibular second premolars, 82.86% were type I, 6.25 type III, 5.32% type II, 4.27% type IV, and 0.69% type V. Conclusion: These results highlight the necessity of searching for additional possible root canals by clinicians. Moreover, these results indicated the ethnical characteristics of Iranian population regarding the morphology of mandibular premolars compared to other populations.Keywords: Anatomy; Iranian; Mandibular Premolar; Review; Root Cana

Cytotoxicity of Selected Nanoparticles on Human Dental Pulp Stem Cells

Introduction: Nanoparticles are being increasingly applied in dentistry due to their antimicrobial and mechanical properties. This in vitro study aimed to assess and compare the cytotoxicity of four metal oxide nanoparticles (TiO2, SiO2, ZnO, and Al2O3) on human dental pulp stem cells. Methods and Materials: Four suspension with different concentrations (25, 50, 75, 100 µg/mL) of each nanoparticle were prepared and placed into cavities of three 96-well plates (containing 1×104 cells per well that were seeded 24 earlier). All specimens were incubated in a humidified incubator with 5% CO2 at 37°C. Mosmann’s Tetrazolium Toxicity (MTT) assay was used to determine in vitro cytotoxicity of test materials on pulpal stem cells. Cell viability was determined at 24, 48, and 72 h after exposure. Data comparisons were performed using a general linear model for repeated measures and Tukey's post hoc test. The level of significance was set at 0.05. Results: The tested nanoparticles showed variable levels of cytotoxicity and were dose and time dependant. The minimum cell viability was observed in ZnO followed by TiO2, SiO2 and Al2O3. Conclusion: The results demonstrated that cell viability and morphological modifications occurred at the concentration range of 25 to 100 µg/mL and in all nanoparticles. The higher concentration and longer duration of exposure increased cellular death. Our results highlight the need for a more discrete use of nanoparticles for biomedical applications.Keywords: Cytotoxicity; Dental Pulp Stem Cells; Metal Oxide Nanoparticle

Effect of Amperage and Field of View on Detection of Vertical Root Fracture in Teeth with Intracanal Posts

Introduction: This study sought to assess the effects of amperage (mA) and field of view (FOV) on intracanal metal post artifacts and the diagnostic parameters for detection of vertical root fracture (VRF) in teeth with intracanal posts. Methods and Materials: In this diagnostic study, 80 human single-canal teeth were evaluated by cone-beam computed tomography (CBCT). Nickel chrome cast posts were placed into root canals after root canal therapy and canal preparation. In the test group, fracture was induced by an instron machine while no fracture was induced in the control group. Deterministic and probabilistic sensitivity and specificity values at different exposure settings were statistically analyzed using the one-way ANOVA and pairwise comparisons were performed by Tukey’s test. Results: Significant differences were found between the two groups in terms of deterministic (P<0.0001) and probabilistic (P<0.013) sensitivity and deterministic (P<0.037) and probabilistic (P<0.0001) specificity at different FOV and mA combinations. Conclusion: A smaller FOV and lower mA should be preferably used for detection of VRFs in teeth with intracanal posts.Keywords: Amperage; Cone-Beam Computed Tomography; Field of View; Metal Artifact; Vertical Root Fractur

A Clinical Risk Assessment of a 3D-Printed Patient-Specific Scaffold by Failure Modes and Effects Analysis

This study aims to carry out a risk assessment to identify and rectify potential clinical risks of a 3D-printed patient-specific scaffold for large-volume alveolar bone regeneration. A survey was used to assess clinicians’ perceptions regarding the use of scaffolds in the treatment of alveolar defects and conduct a clinical risk assessment of the developed scaffold using the Failure Modes and Effects Analysis (FMEA) framework. The response rate was 69.4% with a total of 41 responses received. Two particular failure modes were identified as a high priority through the clinical risk assessment conducted. The highest mean Risk Priority Number was obtained by “failure of healing due to patient risk factors” (45.7 ± 27.7), followed by “insufficient soft tissue area” (37.8 ± 24.1). Despite the rapid developments, finding a scaffold that is both biodegradable and tailored to the patient’s specific defect in cases of large-volume bone regeneration is still challenging for clinicians. Our results indicate a positive perception of clinicians towards this novel scaffold. The FMEA clinical risk assessment has revealed two failure modes that should be prioritized for risk mitigation (safe clinical translation). These findings are important for the safe transition to in-human trials and subsequent clinical use

Microbial Decontamination and Antibacterial Activity of Nanostructured Titanium Dental Implants: A Narrative Review

Peri-implantitis is the major cause of the failure of dental implants. Since dental implants have become one of the main therapies for teeth loss, the number of patients with peri-implant diseases has been rising. Like the periodontal diseases that affect the supporting tissues of the teeth, peri-implant diseases are also associated with the formation of dental plaque biofilm, and resulting inflammation and destruction of the gingival tissues and bone. Treatments for peri-implantitis are focused on reducing the bacterial load in the pocket around the implant, and in decontaminating surfaces once bacteria have been detached. Recently, nanoengineered titanium dental implants have been introduced to improve osteointegration and provide an osteoconductive surface; however, the increased surface roughness raises issues of biofilm formation and more challenging decontamination of the implant surface. This paper reviews treatment modalities that are carried out to eliminate bacterial biofilms and slow their regrowth in terms of their advantages and disadvantages when used on titanium dental implant surfaces with nanoscale features. Such decontamination methods include physical debridement, chemo-mechanical treatments, laser ablation and photodynamic therapy, and electrochemical processes. There is a consensus that the efficient removal of the biofilm supplemented by chemical debridement and full access to the pocket is essential for treating peri-implantitis in clinical settings. Moreover, there is the potential to create ideal nano-modified titanium implants which exert antimicrobial actions and inhibit biofilm formation. Methods to achieve this include structural and surface changes via chemical and physical processes that alter the surface morphology and confer antibacterial properties. These have shown promise in preclinical investigations

Laser‐assisted nucleic acid delivery: a systematic review

Gene therapy has become an effective treatment modality for some conditions. Laser light may augment or enhance gene therapy through photomechanical, photothermal, and photochemical. This review examined the evidence base for laser therapy to enhance nucleic acid transfection in mammalian cells. An electronic search of MEDLINE, Scopus, EMBASE, Web of Science, and Google Scholar was performed, covering all available years. The preferred reporting items for systematic reviews and meta-analyses guideline for systematic reviews was used for designing the study and analyzing the results. In total, 49 studies of laser irradiation for nucleic acid delivery were included. Key approaches were optoporation, photomechanical gene transfection, and photochemical internalization. Optoporation is better suited to cells in culture, photomechanical and photochemical approaches appear well suited to in vivo use. Additional studies explored the impact of photothermal for enhancing gene transfection. Each approach has merits and limitations. Augmenting nucleic acid delivery using laser irradiation is a promising method for improving gene therapy. Laser protocols can be non-invasive because of the penetration of desirable wavelengths of light, but it depends on various parameters such as power density, treatment duration, irradiation mode, etc. The current protocols show low efficiency, and there is a need for further work to optimize irradiation parameters