Sağlıklı ve Çürük Diş Dokularının Mekanik Özelliklerinin Nanoindentasyon Yöntemiyle Karşılıklı Olarak İncelenmesi

Giriş ve Amaç: Çalışmamızın amacı nanoindentasyon yöntemiyle diş sert dokularının ve farklı aşamalardaki çürük lezyonunun mekanik özelliklerinin karşılaştırmalı olarak incelenmesidir. Yöntem ve Gereçler: Nanoindentasyon test yöntemi için yarı retansiyonlu ve sürme güçlüğü nedeniyle çekilmiş üçüncü alt molar dişler kullanılmıştır. 2 mm kalınlığında diskler şeklinde hazırlanan mine ve dentin örnekleri toplamda 6 gruba ayrılarak (n=12), DUH-W201S nanoindentasyon cihazında test edilmiş ve her bir örneğe ait gerilme, gerinim, sertlik, elastisite modülü, akma dayanımı ve kırılma tokluğu değerleri ölçülmüştür. Gruplar arasında fark olup olmadığı Kruskal Wallis ve Mann Whitney U testleri ile, sağlıklı mine ve dentin gruplarının demineralizasyona bağlı değişimi ise Wilcoxen Sum Rank Testi ile incelenmiştir (p=0.01). Bulgular: Sağlıklı mine dokusunun sertlik, gerilme, elastisite modülü, akma dayanımı ve kırılma tokluğu değerlerinin diğer gruplara kıyasla yüksek olduğu belirlenmiştir. Demineralize mine ve dentin dokularından elde edilen sertlik ve gerilme değerleri sağlıklı mine ve dentin dokularına kıyasla %90 oranında azalırken, gerinim (%265), kırılma tokluğu (%45) ve elastik toparlanma değerleri (%160) artmıştır. Demineralize mine ve dentin dokuları arasında tüm mekanik özellikler açısından istatistiksel olarak anlamlı fark varken (p=0.000), mine ve dentin çürükleri arasında tüm mekanik özellikler açısından fark bulunmamaktadır (p=0.099). Tartışma ve Sonuç: Farklı diş dokularında meydana gelen demineralizasyon işlemi dişin mekanik özelliklerini azaltırken, dişin yapısını daha esnek ve fiziksel açıdan zayıf hale getirmektedir.

Comparative Evaluation of Mechanical Properties of Dental Nanomaterials

This study examines the properties of nanobased dental restorative materials with nanoindentation method in a precise, repeatable, and comparable way. Microhybrid and nanohybrid composites, conventional glass ionomer materials, and light cured nanoionomer materials were utilised for the study. Specimen discs (r=10 mm, h= 2 mm) were prepared to test the hardness, modulus of elasticity, yield strength, and fracture toughness values for each sample in a nanoindentation device with an atomic force microscopy add-on (n=25). Comparative analyses were performed by one-way ANOVA and post hoc Tukey tests. The hardness and modulus of elasticity values of nanocomposite were higher (2.58 GPa and 32.86 GPa, resp.) than those of other dental materials. Although glass ionomer exhibited a hardness that was similar to a nanoionomer (0.81 versus 0.87 GPa), glass ionomer had the lowest fracture toughness value (Kc=0.83 MPa/mm0.5). The mechanical properties of resin composites improve with additional nanoscale fillers, unlike the glass ionomer material

Evaluation of the Mechanical and Adhesion Characteristics of Indirect Restorations Manufactured with Three-Dimensional Printing

The aim of this study was to investigate the marginal fit and bond strength characteristics of onlay restorations manufactured by three-dimensional printing (Varseo XS, Bego GmbH, Bremen, Germany) and CAD/CAM (CAMcube, Montreal, QC, Canada) systems. Class II onlay cavities on sixty mandibular molars were prepared in cavities and restored in three separate groups using different fabrication methods. Digital and conventional impressions were taken to design the restorations in the CAD system (DWOS, Straumann GmbH, Freiburg, Germany). To evaluate the marginal fit and void volumes, all specimens were scanned with microcomputed tomography. A microshear test was performed to compare the bond strength of the restorations to the tooth surface. The marginal fit values measured for the 3D-printed and CAD/CAM onlay restorations were found to be at clinically acceptable levels (p > 0.05). According to the microshear test results, the CAD/CAM group had the highest bond strength values before (34.82 MPa) and after (26.87 MPa) thermal cycling (p p < 0.05). 3D printing technology is a promising option for indirect restorations; however, the post-production phase is as crucial as the printing and cementation phases

Evaluation of the relationship between migraine disorder and oral comorbidities: multicenter randomized clinical trial

WOS: 000374327500019PubMed ID: 27513246Background/aim: Although migraine is a common disorder, there is a lack of research investigating the possible relationship between migraine and oral health. The aim of the present study was to explore the relationship between temporomandibular disorders, bruxism, dental caries, periodontal status, and migraine disorder in a multicenter, parallel, case-controlled clinical study. Materials and methods: A total of 2001 participants were divided into two groups: migraineurs (nm = 998) and nonmigraineurs (nh = 1003). International Headache Society's Second Edition of International Classification of Headache Disorders and modified Migraine Disability Assessment surveys were administered to evaluate the level of migraine; a pretreatment questionnaire and the World Health Organization oral health assessment form were used to determine the oral comorbidities and their possible effects on DMFT index, gingival plaque index, existence of temporomandibular disorders, bruxism, and consistency of daily oral hygiene habits. Results: The mean age was 39.6 +/- 10.5 years. Female patients seemed to experience migraine attacks more than male patients (64%). The frequency of gastroesophageal reflux was higher in migraineurs in comparison with nonmigraineurs (47%) and tooth wear and abrasion also seemed more frequent (76%). DMFT and plaque index scores showed significant differences for both groups. Conclusion: There is a strong relationship between migraine and oral health status. The existence of reflux in addition to migraine leads to higher dental problems

Evaluation of the relationship between migraine disorder and oral comorbidities: multicenter randomized clinical trial

Background/aim: Although migraine is a common disorder, there is a lack of research investigating the possible relationship between migraine and oral health. The aim of the present study was to explore the relationship between temporomandibular disorders, bruxism, dental caries, periodontal status, and migraine disorder in a multicenter, parallel, case-controlled clinical study. Materials and methods: A total of 2001 participants were divided into two groups: migraineurs (nm = 998) and nonmigraineurs (nh = 1003). International Headache Society's Second Edition of International Classification of Headache Disorders and modified Migraine Disability Assessment surveys were administered to evaluate the level of migraine; a pretreatment questionnaire and the World Health Organization oral health assessment form were used to determine the oral comorbidities and their possible effects on DMFT index, gingival plaque index, existence of temporomandibular disorders, bruxism, and consistency of daily oral hygiene habits. Results: The mean age was 39.6 +/- 10.5 years. Female patients seemed to experience migraine attacks more than male patients (64\%). The frequency of gastroesophageal reflux was higher in migraineurs in comparison with nonmigraineurs (47\%) and tooth wear and abrasion also seemed more frequent (76\%). DMFT and plaque index scores showed significant differences for both groups. Conclusion: There is a strong relationship between migraine and oral health status. The existence of reflux in addition to migraine leads to higher dental problems

Evaluation of oral health status and immunological parameters of hospitalized COVID-19 patients during acute and recovery phases: A randomized clinical trial

Background/purpose: It is known that COVID-19 patients show many clinical oral symptoms due to the immunological mechanisms triggered by the virus. Aim of this study is to analyze the antibody response to SARS-CoV-2, and to evaluate the oral health status of hospitalized patients. Materials and methods: 160 patients with COVID-19 confirmed by SARS-CoV-2–specific RT-PCR testing and 160 healthy volunteers (HI) with similar age, gender and systemic status were included to compare the bio-chemical and oral manifestations. Oropharyngeal swab specimens were collected to evaluate the salivary interleukins (IL-1, IL-6, IL-10) and immunoglobulins (sIgA, sIgG, sIgM). Oral findings (DMFT, plaque index, salivary flow rate), socio-demographic information and systemic conditions were also recorded. Chi-square, Mann–Whitney U and Spearman's ratio tests were applied to determine the possible correlations between the factors (P = 0.05). Results: The mean DMFT scores of COVID-19 patients (12.71 ± 7.3) were significantly higher than the HI (7.39 ± 2.8), whereas cases of total or partial edentulism were more common among COVID-19 patients (P 0.05), salivary parameters were found statistically different (P < 0.05). Severe and moderate cases showed higher proinflammatory interleukin levels (IL-1 = 68.74 pg/ml, IL-6 = 53.31 pg/ml) amongst all (P < 0.05). While secretory immunoglobulins were almost depleted at baseline, (sIgA = 0.11 mg/ml, sIgG = 0.21 mg/ml, sIgM = 0.08 mg/ml) they reached to threshold levels after 4 weeks. Conclusion: Higher proinflammatory interleukin levels indicated that traces of ongoing “Cytokine Storm” in COVID-19 patients which can also be observed in oral environment. Poor oral hygiene and malnutrition due to edentulism can pave the way for having a severe COVID-19 infection