Potential Co-Factors of an Intraoral Contact Allergy—A Cross-Sectional Study

The aim of this cross-sectional study was to evaluate the frequency of dental allergens and potential co-factors, especially hypothyroidism, for patients with an intraoral contact allergy. From 2015 to 2016, patients with confirmed symptoms of an intraoral contact allergy (study group SG n = 50) were recruited in the dental clinic of the University of Leipzig. The participants of the control group (CG n = 103) were patients without oral diseases or intraoral symptoms of a contact allergy. For the data collection, a new “Allergy questionnaire” was developed. Information on allergies and general diseases were collected. The statistical analysis was carried out with SPSS 23.0. Sensitizations/allergies to metals and composites were higher in SG compared to CG. Of all study participants (n = 148), 14.2% (n = 21) had a nickel allergy. In 18% (n = 8) of the SG a cobalt allergy based on all metal allergens could be seen. In addition, an association between a nickel and cobalt allergy was found. Hypothyroidism occurred significantly more frequently (p = 0.049) in SG than in CG. Sensitizations and allergies can occur to metals in dental alloys. Hypothyroidism increased the risk of having an allergy threefold

Potential Co-Factors of an Intraoral Contact Allergy—A Cross-Sectional Study

The aim of this cross-sectional study was to evaluate the frequency of dental allergens and potential co-factors, especially hypothyroidism, for patients with an intraoral contact allergy. From 2015 to 2016, patients with confirmed symptoms of an intraoral contact allergy (study group SG n = 50) were recruited in the dental clinic of the University of Leipzig. The participants of the control group (CG n = 103) were patients without oral diseases or intraoral symptoms of a contact allergy. For the data collection, a new “Allergy questionnaire” was developed. Information on allergies and general diseases were collected. The statistical analysis was carried out with SPSS 23.0. Sensitizations/allergies to metals and composites were higher in SG compared to CG. Of all study participants (n = 148), 14.2% (n = 21) had a nickel allergy. In 18% (n = 8) of the SG a cobalt allergy based on all metal allergens could be seen. In addition, an association between a nickel and cobalt allergy was found. Hypothyroidism occurred significantly more frequently (p = 0.049) in SG than in CG. Sensitizations and allergies can occur to metals in dental alloys. Hypothyroidism increased the risk of having an allergy threefold

Potential Co-Factors of an Intraoral Contact Allergy—A Cross-Sectional Study

The aim of this cross-sectional study was to evaluate the frequency of dental allergens and potential co-factors, especially hypothyroidism, for patients with an intraoral contact allergy. From 2015 to 2016, patients with confirmed symptoms of an intraoral contact allergy (study group SG n = 50) were recruited in the dental clinic of the University of Leipzig. The participants of the control group (CG n = 103) were patients without oral diseases or intraoral symptoms of a contact allergy. For the data collection, a new “Allergy questionnaire” was developed. Information on allergies and general diseases were collected. The statistical analysis was carried out with SPSS 23.0. Sensitizations/allergies to metals and composites were higher in SG compared to CG. Of all study participants (n = 148), 14.2% (n = 21) had a nickel allergy. In 18% (n = 8) of the SG a cobalt allergy based on all metal allergens could be seen. In addition, an association between a nickel and cobalt allergy was found. Hypothyroidism occurred significantly more frequently (p = 0.049) in SG than in CG. Sensitizations and allergies can occur to metals in dental alloys. Hypothyroidism increased the risk of having an allergy threefold

Development and implementation of the Clinical Tooth Shade Differentiation Course – an evaluation over 3 years

Objective: Tooth shade differentiation concerns the identification and classification of tooth shades. The objective of this project was to implement the Clinical Tooth Shade Differentiation Course in the preclinical stage of studies and to evaluate the students' perspective over a period of 3 years.Methodology: The course is planned for a duration of 10 weeks with two 45-minute sessions per semester week. The entire attendance time was 10:15 h. 2 lectures of 90 minutes each, 2 seminars of 60 min each and 2 teaching units with the phantom head and role playing took place. In addition to the various parameters of tooth shade, changes in tooth shade and the basics of dental esthetics, clinical procedures for manual and digital tooth shade determination were explained and practiced. 96% (69 of 72) of the students participated in the first evaluation in 2012/2013 (T), and 68% of these were women. In the following year, 2013/2014 (T), 92% (45 of 48 students) took part; 62% of these were women and 38% men. The 2014/2015 evaluation (T) comprised 94% (45 of 48 students). Of these, 67% were women.Results: In the evaluation, the students gave the course a positive grade. The questions in "General/Organization" were given a mean (M) of 1.5 (SD=0.7) in T and T , and 1.2 (SD=0.3) in T. The "Overall Assessment" yielded M=1.6 (SD=0.6), M=1.5 (SD=0.5) and M=1.1 (SD=0.3). In T and T, the item "The instructor actively involved the students in the course" was given a mean of 2.1 (SD=0.9), and in T a mean of 1.2 (SD=0.5). Conclusions: The course presented here conceptually shows how practical dental skills can be taught in a theoretical and clinical context. Educational objectives from the role of a dental expert were taken from the national competence-based catalog of educational objectives for dentistry and can also be supplemented. The objectives can be transferred to other dental faculties

Potential Co-Factors of an Intraoral Contact Allergy—A Cross-Sectional Study

The aim of this cross-sectional study was to evaluate the frequency of dental allergens and potential co-factors, especially hypothyroidism, for patients with an intraoral contact allergy. From 2015 to 2016, patients with confirmed symptoms of an intraoral contact allergy (study group SG n = 50) were recruited in the dental clinic of the University of Leipzig. The participants of the control group (CG n = 103) were patients without oral diseases or intraoral symptoms of a contact allergy. For the data collection, a new “Allergy questionnaire” was developed. Information on allergies and general diseases were collected. The statistical analysis was carried out with SPSS 23.0. Sensitizations/allergies to metals and composites were higher in SG compared to CG. Of all study participants (n = 148), 14.2% (n = 21) had a nickel allergy. In 18% (n = 8) of the SG a cobalt allergy based on all metal allergens could be seen. In addition, an association between a nickel and cobalt allergy was found. Hypothyroidism occurred significantly more frequently (p = 0.049) in SG than in CG. Sensitizations and allergies can occur to metals in dental alloys. Hypothyroidism increased the risk of having an allergy threefold

Biomechanical properties of polymer-infiltrated ceramic crowns on one-piece zirconia implants after long-term chewing simulation

Abstract Background Implant and superstructure provide a complex system, which has to withstand oral conditions. Concerning the brittleness of many ceramics, fractures are a greatly feared issue. Therefore, polymer-infiltrated ceramic networks (PICNs) were developed. Because of its high elastic modulus, the PICN crown on a one-piece zirconia implant might absorb forces to prevent the system from fracturing in order to sustain oral forces. Recommendations for the material of superstructure on zirconia implants are lacking, and only one study investigates PICN crowns on these types of implants. Accordingly, this study aimed to examine PICN crowns on one-piece zirconia implants regarding bond strength and surface wear after long-term chewing simulation (CS). Methods Twenty-five hybrid ceramic crowns (Vita Enamic, Vita Zahnfabrik) were produced using computer-aided design/computer-aided manufacturing (CAD/CAM) technology and adhesively bonded (RelyX™ Ultimate, 3M ESPE) to zirconia implants. Twenty of the specimens underwent simultaneous mechanical loading and thermocycling simulating a 5-year clinical situation (SD Mechatronik GmbH). Wear depth and wear volume, based on X-ray micro-computed tomography volume scans (Skyscan 1172-100-50, Bruker) before and after CS, were evaluated. All crowns were removed from the implants using a universal testing machine (Z010, Zwick GmbH&Co.KG). Subsequently, luting agent was light microscopically localized (Stemi 2000-C, Zeiss). With a scanning electron microscope (SEM, Phenom™ G2 pro, Phenom World), the area of abrasion was assessed. Results 1.After CS, none of the tested crowns were fractured or loosened.2.The maximum vertical wear after CS was M = 0.31 ± 0.04 mm (mean ± standard deviation), and the surface wear was M = 0.74 ± 0.23 mm3.3.The pull-off tests revealed a 1.8 times higher bond strength of the control group compared to the experimental group (t(23) = 8.69, p < 0.001).4.Luting agent was mostly located in the crowns, not on the implants.5.The area of abrasion showed avulsion and a rough surface. Conclusions PICN on one-piece zirconia implants showed high bond strength and high wear after CS

Contact allergies to dental materials

There is a lack of epidemiological data on allergies to dental materials. For example, in the recently published fifth German Oral Health Study (DMS V), no information was given on any common allergies or allergies to dental materials. The aim of the present observational study was therefore to determine the frequencies and symptoms of allergies to dental materials. A public consultation hour for allergies of the oral mucosa and material incompatibilities has been integrated in the Department of Dental Prosthodontics and Materials Science in Leipzig, where clinical patient data have systematically been collected since 2012. The objective mucosal findings and the patients’ complaints are documented in detail in a specifically designed data sheet. This study included 86 subjects (83.7% women and 16.3% men) with oral symptoms of a contact allergy. The average age was 63 years (24–86). The most common allergies were to metals, of which nickel and cobalt were the most common allergens. Furthermore, many allergies were indicated to ingredients of cosmetics and composites. Allergies to components in methacrylate-containing denture resins came in at rank 5. 52.4% of the patients showed mucosal changes. Contact stomatitis (54.5%) and an oral lichenoid lesion (20.5%) were most frequently diagnosed. 86% of the patients reported subjective complaints. Pain and burning sensations in the mouth were mostly reported. Appropriate dental allergy history, clinical examination of the oral cavity for changes in the oral mucosa, analysis of specific dentures, and screening for psychogenic disorders are necessary to clarify the origin of these symptoms

Bacterial Colonization and Tissue Compatibility of Denture Base Resins

Currently, there is minimal clinical data regarding biofilm composition on the surface of denture bases and the clinical tissue compatibility. Therefore, the aim of this experimental study was to compare the bacterial colonization and the tissue compatibility of a hypoallergenic polyamide with a frequently used PMMA resin tested intraorally in a randomized split-mouth design. Test specimens made of polyamide (n = 10) and PMMA (n = 10) were attached over a molar band appliance in oral cavity of 10 subjects. A cytological smear test was done from palatal mucosa at baseline and after four weeks. The monolayers were inspected for micronuclei. After four weeks in situ, the appliance was removed. The test specimens were immediately cultivated on non-selective and selective nutrient media. All growing colonies were identified using VITEK-MS. The anonymized results were analyzed descriptively. A total of 110 different bacterial species could be isolated, including putative pathogens. An average of 17.8 different bacterial species grew on the PMMA specimens, and 17.3 on the polyamide specimens. The highest number of different bacterial species was n = 24, found on a PMMA specimen. On the two specimens, a similar bacterial distribution was observed. Micronuclei, as a marker for genotoxic potential of dental materials, were not detected. This study indicates that the composition of bacterial biofilm developed on these resins after four weeks is not influenced by the type of resin itself. The two materials showed no cytological differences. This investigation suggests that polyamide and PMMA are suitable for clinical use as denture base material

Clinical comparison of liquid-based and conventional cytology of oral brush biopsies: a randomized controlled trial

Abstract Background Exfoliative cytology performed on oral brush samples can help dentists to decide, whether a given oral lesion is (pre-) malignant. The use of non-invasive brush biopsies as an auxiliary tool in the diagnosis of oral mucosal lesions has gained renewed interest since improvements in cytological techniques such as the development of adjuvant diagnostic tools and liquid-based cell preparation techniques. Methods The aim of this study was to compare the quality of two different preparation techniques (cell collectors): the conventional transfer procedure to glass slides and the so-called liquid-based cytology preparation method. Cell smears were collected from 10 orally healthy individuals (mean age: 24 years) from the palatine mucosa at two different times (baseline and 4 weeks later). Slides of both techniques were stained by Giemsa (n = 40) and May-Gruenwald Giemsa (n = 40). The statistical analysis was performed with Excel. Results On specimen analysis, the liquid-based cytology showed statistically significant improvement compared to conventional glass sides (p < 0.001). Thin layers, which were performed by liquid-based cytology showed significantly better results in the parameters (p < 0.001): uniform distribution, cellular overlapping, cellular disformation, mucus, microbial colonies and debris. The conventional glass slides approach showed more cell overlapping and contamination with extraneous material than thin layers, which were performed by Orcellex® Brush cell collectors. Conclusions Both techniques are diagnostically reliable. The liquid-based method showed an overall improvement on sample preservation, specimen adequacy, visualization of cell morphology and reproducibility. Liquid-based cytology simplifies cell collection due to easier handling and less transfer errors by dentists