Impact of different cephalometric skeletal configurations on anatomic midface parameters in adults.

OBJECTIVES: Skull morphology and growth patterns are essential for orthodontic treatment, impacting clinical decision making. We aimed to determine the association of different cephalometric skeletal configurations on midface parameters as measured in 3D CT datasets. MATERIALS AND METHODS: After sample size calculation, a total of 240 fully dentulous patients between 20 and 79 years of age (mean age: 42 ± 15), who had received a CT of the skull within the scope of trauma diagnosis or intracranial bleeding, were retrospectively selected. On the basis of cephalometric analysis, using MPR reconstructions, patients were subdivided into three different vertical skull configurations (brachyfacial, mesofacial, dolichofacial) and the respective skeletal Class I, II, and III relationships. Anatomic parameters were measured using a three-dimensional post-processing console: the thickness of the maxillary and palatine bones as well as the alveolar crest, maxillary body and sutural length, width and height of the hard palate, maxillary facial wall thickness, and masseter muscle thickness and length. RESULTS: Individuals with brachyfacial configurations had a significantly increased palatal and alveolar ridge thicknesses compared to those with dolichofacial- or mesofacial configurations. Brachyfacial configurations presented a significantly increased length and thickness of the masseter muscle (4.599 cm; 1.526 cm) than mesofacial (4.431 cm; 1.466 cm) and dolichofacial configurations (4.405 cm; 1.397 cm) (p < 0.001). Individuals with a skeletal Class III had a significantly shorter palatal length (5.313 cm) than those with Class I (5.406 cm) and Class II (5.404 cm) (p < 0.01). Sutural length was also significantly shorter in Class III (p < 0.05). CONCLUSIONS: Skeletal configurations have an impact on parameters of the bony skull. Also, measurable adaptations of the muscular phenotype could result. CLINICAL RELEVANCE: The association between viscerocranial morphology and midface anatomy might be beneficial for tailoring orthodontic appliances to individual anatomy and planning cortically anchored orthodontic appliances.

Cinematic rendering to improve visualization of supplementary and ectopic teeth using CT datasets.

OBJECTIVES: Ectopic, impacted, and supplementary teeth are the number one reason for cross-sectional imaging in pediatric dentistry. The accurate post-processing of acquired data sets is crucial to obtain precise, yet also intuitively understandable three-dimensional (3D) models, which facilitate clinical decision-making and improve treatment outcomes. Cinematic rendering (CR) is anovel visualization technique using physically based volume rendering to create photorealistic images from DICOM data. The aim of the present study was to tailor pre-existing CR reconstruction parameters for use in dental imaging with the example of the diagnostic 3D visualization of ectopic, impacted, and supplementary teeth. METHODS: CR was employed for the volumetric image visualization of midface CT data sets. Predefined reconstruction parameters were specifically modified to visualize the presented dental pathologies, dentulous jaw, and isolated teeth. The 3D spatial relationship of the teeth, as well as their structural relationship with the antagonizing dentition, could immediately be investigated and highlighted by separate, interactive 3D visualization after segmentation through windowing. RESULTS: To the best of our knowledge, CR has not been implemented for the visualization of supplementary and ectopic teeth segmented from the surrounding bone because the software has not yet provided appropriate customized reconstruction parameters for dental imaging. When employing our new, modified reconstruction parameters, its application presents a fast approach to obtain realistic visualizations of both dental and osseous structures. CONCLUSIONS: CR enables dentists and oral surgeons to gain an improved 3D understanding of anatomical structures, allowing for more intuitive treatment planning and patient communication.

Evaluating Cardiac Lateralization by MRI to Simplify Estimation of Cardiopulmonary Impairment in Pectus Excavatum.

BACKGROUND: The severity of pectus excavatum is classified by the Haller Index (HI) and/or Correction Index (CI). These indices measure only the depth of the defect and, therefore, impede a precise estimation of the actual cardiopulmonary impairment. We aimed to evaluate the MRI-derived cardiac lateralization to improve the estimation of cardiopulmonary impairment in Pectus excavatum in connection with the Haller and Correction Indices. METHODS: This retrospective cohort study included a total of 113 patients (mean age = 19.03 ± 7.8) with pectus excavatum, whose diagnosis was verified on cross-sectional MRI images using the HI and CI. For the development of an improved HI and CI index, the patients underwent cardiopulmonary exercise testing to assess the influence of the right ventricle's position on cardiopulmonary impairment. The indexed lateral position of the pulmonary valve was utilized as a surrogate parameter for right ventricle localization. RESULTS: In patients with PE, the heart's lateralization significantly correlated with the severity of pectus excavatum (p ≤ 0.001). When modifying HI and CI for the individual's pulmonary valve position, those indices are present with greater sensitivity and specificity regarding the maximum oxygen-pulse as a pathophysiological correlate of reduced cardiac function (χ2 10.986 and 15.862, respectively). CONCLUSION: The indexed lateral deviation of the pulmonary valve seems to be a valuable cofactor for HI and CI, allowing for an improved description of cardiopulmonary impairment in PE patients.

Orofacial clefts alter early life oral microbiome maturation towards higher levels of potentially pathogenic species: A prospective observational study.

Orofacial clefts (OFC) present different phenotypes with a postnatal challenge for oral microbiota development. In order to investigate the impact of OFC on oral microbiota, smear samples from 15 neonates with OFC and 17 neonates without OFC were collected from two oral niches (tongue, cheek) at two time points, i.e. after birth (T0: Ø3d OFC group; Ø2d control group) and 4-5 weeks later (T1: Ø32d OFC group; Ø31d control group). Subsequently, the samples were analyzed using next-generation sequencing. We detected a significant increase of alpha diversity and anaerobic and Gram-negative species from T0 to T1 in both groups. Further, we found that at T1 OFC neonates presented a significantly lower alpha diversity (lowest values for high cleft severity) and significantly higher levels of Enterobacteriaceae (Citrobacter, Enterobacter, Escherichia-Shigella, Klebsiella), Enterococcus, Bifidobacterium, Corynebacterium, Lactocaseibacillus, Staphylococcus, Acinetobacter and Lawsonella compared to controls. Notably, neonates with unilateral and bilateral cleft lip and palate (UCLP/BCLP) presented similarities in beta diversity and a mixture with skin microbiota. However, significant differences were seen in neonates with cleft palate only compared to UCLP/BCLP with higher levels of anaerobic species. Our findings revealed an influence of OFC as well as cleft phenotype and severity on postnatal oral microbiota maturation.

Orofacial clefts lead to increased pro-inflammatory cytokine levels on neonatal oral mucosa.

Orofacial clefts (OFC) are frequent congenital malformations characterized by insufficient separation of oral and nasal cavities and require presurgical infant orthopedics and surgical interventions within the first year of life. Wound healing disorders and higher prevalence of gingivitis and plaque levels are well-known challenges in treatment of children with OFC. However, oral inflammatory mediators were not investigated after birth using non-invasive sampling methods so far. In order to investigate the impact of OFC on oral cytokine levels, we collected tongue smear samples from 15 neonates with OFC and 17 control neonates at two time points (T), T0 at first consultation after birth, and T1, 4 to 5 weeks later. The samples were analyzed using multiplex immunoassay. Overall, we found significantly increased cytokine levels (TNF, IL-1ß/-2/-6/-8/-10) in tongue smear samples from neonates with OFC compared to controls, especially at T0. The increase was even more pronounced in neonates with a higher cleft severity. Further, we detected a significant positive correlation between cleft severity score and distinct pro-inflammatory mediators (GM-CSF, IL-1ß, IL-6, IL-8) at T0. Further, we found that breast-milk (bottle) feeding was associated with lower levels of pro-inflammatory cytokines (IL-6/-8) in neonates with OFC compared to formula-fed neonates. Our study demonstrated that neonates with OFC, especially with high cleft severity, are characterized by markedly increased inflammatory mediators in tongue smear samples within the first weeks of life potentially presenting a risk for oral inflammatory diseases. Therefore, an inflammatory monitoring of neonates with (severe) OFC and the encouragement of mother to breast-milk (bottle) feed might be advisable after birth and/or prior to cleft surgery.

Congenital Nail Disorders among Children with Suspected Ectodermal Dysplasias.

We report on a cohort of 204 children referred between January 2017 and January 2022 to the German Center for Ectodermal Dysplasias, Erlangen. The most frequent reasons for referral were tooth malformations and lack of multiple teeth leading to the suspicion of an ectodermal dysplasia. Many patients also suffered from being unable to perspire. Nail abnormalities, in contrast, represented a much rarer finding, albeit the impact on some individuals was large. As ectodermal dysplasias are congenital genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands, we analyzed congenital nail disorders detected in these patients. Dystrophic or otherwise abnormal nails were evident in 17 of 18 subjects with pathogenic WNT10A or GJB6 variants but in none of 161 children with EDA variants underlying X-linked hypohidrotic ectodermal dysplasia. However, 2 of 17 children who carry mutations in EDAR or EDARADD, two other genes involved in the ectodysplasin A signaling pathway, showed nail abnormalities, such as brittle or hypoplastic nails. TP63 variants were regularly associated with nail disorders. In one girl, anonychia congenita caused by a compound heterozygous variant of the R-spondin-4 gene (RSPO4) was diagnosed. Thus, nail dysplasia is rarer among patients with ectodermal dysplasia than commonly thought.

The comparison of the morphology of the mid-palatal suture between edentulous individuals and dentate jaws shows morphological differences.

BACKGROUND: A profound understanding of the evolution and anatomy of the viscero- and neurocranium is quintessentially important for orthodontists. This particularly alludes to structures, which are directly targeted by orthodontic therapy such as the maxilla and the mid-palatal suture. The anatomy of the mid-palatal suture of toothed individuals is well described, whereas little is known about sutures' morphological changes after tooth loss. Therefore, the aim of this study was to evaluate the edentulous mid-palatal suture by means of histologic and histomorphometric analysis. METHODS: Ten mid-palatal sutures of edentulous donors as well as six age- and sex matched dentulous controls were examined. For the histological and histomorphometric analysis (sutural width, obliteration, vascularization and interdigitation) conventional staining protocols (HE, Movat-Pentachrome, Sirius Red) and immunofluorescence (vWF, TRAP) were performed. Histomorphometric analysis was carried out using NIS-elements imaging software. RESULTS: When compared to dentulous controls, the edentulous investigation group showed a decreased vascularization and sutural width as well as an increased sutural obliteration. Notably, a high variability and inhomogeneity within regard the histomorphometric parameters was seen in edentulous samples. CONCLUSIONS: The mid-palatal suture of edentulous individuals showed significant morphological differences compared to individuals with toothed jaws. The loss of teeth and thereby functional loading seems to have a considerable impact on sutures' morphology.

Halitosis in Oral and Maxillofacial Surgery Patients - a Pilot Study.

BACKGROUND: Halitosis is a relatively inhomogeneous pathology with an extremely high prevalence in the population. Potential risk factors for bad breath include bacterial decomposition of organic material as well as numerous general and systemic diseases. The aim of the present study was to analyze whether certain subgroups of oral and maxillofacial surgery patients have a higher risk of halitosis. Further the impact of halitosis on the patient's quality of life was ascertained. METHODS: A total of 127 oral and maxillofacial patients aged between 19 and 86 years were enrolled in this study. On account of their underlining disease, patients were divided into five different investigation groups. The dental examination comprised tongue coating, periodontal screening index (PSI), gingival index (GI), PI (plaque index), DMF-T values as well as non-stimulated saliva flow rates. Halitosis was monitored both organoleptically according to Rosenberg and instrumentally by means of a Halimeter®, which records the volatile sulfur compounds (VSC values in ppm). Patients were further asked to fill out questionnaires regarding their medical history and oral hygiene, oral health (OHIP-14), and quality of life (BDI-II). RESULTS: Halitosis values, which were recorded by a Halimeter® correlated with the objective Rosenberg golden standard method. Furthermore, halitosis values correlated with elevated PSI, GI, and DMF-T values as well as the degree of tongue coating. Patients with oral cancer showed significantly higher VSC values compared to all other groups. No difference in VSC values could be found between all other patient groups. CONCLUSIONS: The Halimeter® could be validated as a suitable method for determining halitosis in oral and maxillofacial patients. The significantly increased halitosis values in cancer patients as opposed to all other patient groups suggests the potential of halitosis VSC values as a potential screening method. The development of non-invasive breath tests for diagnosis could be subject of future research.

Genotoxic and cytotoxic potential of methacrylate-based orthodontic adhesives.

OBJECTIVES: The biocompatibility of methacrylate-based adhesives is a topic that is intensively discussed in dentistry. Since only limited evidence concerning the cyto- and genotoxicity of orthodontic adhesives is available, the aim of this study was to measure the genotoxic potential of seven orthodontic methacrylate-based adhesives. MATERIALS AND METHODS: The XTT assay was utilized to determine the cytotoxicity of Assure Plus, Assure Bonding Resin, ExciTE F, OptiBond Solo Plus, Scotchbond Universal Adhesive, Transbond MIP, and Transbond XT after an incubation period of 24 h on human gingival fibroblasts. We also performed the γH2AX assay to explore the genotoxic potential of the adhesives within cytotoxic dose ranges after an incubation period of 6 h. RESULTS: The XTT assay showed a concentration-dependent reduction in cell viability. The decrease in cellular viability was in the same dose range most significant for Assure Plus, rendering it the adhesive material with the highest cytotoxicity. Employing the γH2AX assay, a concentration-dependent increase in H2AX phosphorylation was detected, indicating induction of DNA damage. CONCLUSIONS: For most products, a linear correlation between the material concentration and γH2AX foci was observed. The most severe effect on γH2AX focus induction was found for Transbond MIP, which was the only adhesive in the test group containing the co-initiator diphenyliodonium hexafluorophosphate (DPIHP). CLINICAL RELEVANCE: The data indicate that orthodontic adhesives, notably Transbond MIP, bear a genotoxic potential. Since the study was performed with in vitro cultivated cells, a direct translation of the findings to in vivo exposure conditions should be considered with great diligence.

Biologization of Collagen-Based Biomaterials Using Liquid-Platelet-Rich Fibrin: New Insights into Clinically Applicable Tissue Engineering.

Platelet-rich fibrin (PRF) is a blood concentrate derived from venous blood that is processed without anticoagulants by a one-step centrifugation process. This three-dimensional scaffold contains inflammatory cells and plasma proteins entrapped in a fibrin matrix. Liquid-PRF was developed based on the previously described low-speed centrifuge concept (LSCC), which allowed the introduction of a liquid-PRF formulation of fibrinogen and thrombin prior to its conversion to fibrin. Liquid-PRF was introduced to meet the clinical demand for combination with biomaterials in a clinically applicable and easy-to-use way. The aim of the present study was to evaluate, ex vivo, the interaction of the liquid-PRF constituents with five different collagen biomaterials by histological analyses. The results first demonstrated that large variability existed between the biomaterials investigated. Liquid-PRF was able to completely invade Mucograft® (MG; Geistlich Biomaterials, Wolhusen, Switzerland) and to partly invade Bio-Gide® (BG; Geistlich Biomaterials, Wolhusen, Switzerland) and Mucoderm® (MD; Botiss Biomaterials, Berlin, Germany), and Collprotect® (CP; Botiss Biomaterials, Berlin, Germany) showed only a superficial interaction. The BEGO® collagen membrane (BCM; BEGO Implant Systems) appeared to be completely free of liquid-PRF. These results were confirmed by the different cellular penetration and liquid-PRF absorption coefficient (PAC) values of the evaluated membranes. The present study demonstrates a system for loading biomaterials with a complex autologous cell system (liquid-PRF) in a relatively short period of time and in a clinically relevant manner. The combination of biomaterials with liquid-PRF may be clinically utilized to enhance the bioactivity of collagen-based biomaterials and may act as a biomaterial-based growth factor delivery system.

Development of a novel histological and histomorphometric evaluation protocol for a standardized description of the mid-palatal suture - An ex vivo study.

The hard palate and mid-palatal suture are highly important for orthodontic treatment. In cases of transverse maxillary deficiency, palatal expansion is the treatment of choice. As nowadays a growing number of adult patients receive orthodontic treatment, an understanding of suture development throughout life is important to derive tailored orthodontic treatment techniques for each age group. Histological, histochemical and immunohistochemical stains (haematoxylin & eosin, Azan, Movat pentachrome, Masson-Goldner trichrome, Sirius Red, CD 31, osteopontin and TRAP) and histomorphometric analyses were re-established to detect the structural conditions of the mid-palatal suture in human cadavers of three different age groups (20-39, 40-59 and 60-80 years). The mid-palatal suture of the selected age groups (total of n = 12; n = 4 in every group m = f) exhibited marked differences in sutural morphology and metabolism. A wide, interdigitated and well-vascularized suture was observed in younger specimens compared with straighter and smaller sutures with fewer vessels and lower bone density in the 60-80 year group. The fibre composition within the sutural gap differed between the three age groups. Delicate fibres were found in the 20-39 year group, and a tightly interwoven 3D fibre-network was observed in the 40-59 year group. Atrophy primarily characterized the fibres in the 60-80 year group. This evidence demonstrates differences between the evaluated groups. These results suggest that the staining methods used are suitable for the description and evaluation of the morphology and metabolism of mid-palatal sutures. Further investigation is necessary to provide an in-depth description of sutural maturation over a lifetime.

Association between breast cancer chemotherapy, oral health and chronic dental infections: a pilot study.

Breast cancer has developed to become the leading type of cancer in females. For this study, 80 women were examined after chemotherapy for breast cancer and compared to 80 healthy age-matched women. This cross-sectional study comprised a dental examination with number of teeth, caries frequency (DMFT) and the presence of periodontal diseases (PSI). With the help of X-rays (OPG), the number of root canal fillings and apical lesions (LEO/LPO) were recorded. Furthermore, the education level, body mass index (BMI), smoking habits and general health conditions were recorded. All women completed questionnaires on oral health-related quality of life (OHIP-G14) and general well-being (HADS-D). To assess the influence of cancer therapy on oral health parameters, appropriate generalized linear models were fitted with disease status as main explanatory variable, adjusting for age and education. For OHIP and HADS, we additionally adjusted for number of missing teeth. The examined 160 women showed a comparable mean age (60.4 years) and an average BMI of 24.6. Cancer patients showed a higher risk for missing teeth (p < 0.001) and more apical lesions (p < 0.0041), particularly those of endodontic origin without root canal fillings (p = 0.0046), than the control women. The general well-being of cancer patients was significantly reduced with a HADS score of 9.4 for women with breast cancer compared to 5.3 for the healthy control. This study suggests that women after breast cancer chemotherapy are inclined to have a poorer oral health status with more missing teeth and apical lesions. Therefore, tightly scheduled dental recall visits should be recommended.

Photodynamic Therapy has no Adverse Effects In Vitro on Human Gingival Fibroblasts and Osteoblasts.

BACKGROUND: Invasion of periodontal pockets with persistent microorganisms and subsequent development of a biofilm are the main cause of periodontal infections. In severe cases, additional use of antibiotics to the standard therapy of scaling and root planing (SRP), is necessary, but the use of antibiotics may lead to resistance. As an alternative, the combination of SRP and adjunct photodynamic therapy (PDT) is applied in the treatment of periodontal infections to improve periodontal therapy. The aim of this study was to determine possible side effects of PDT on human gingival fibroblasts (GF) and human osteoblasts (OB). METHODS: GF and OB were either untreated or treated with methylene blue (MB) only, with MB and subsequently irradiation with a soft laser (PDT) or irradiated with a soft laser only. All cells were analyzed for viability using the MTT test, migration capacity using Boyden chambers, and the scratch wound assay. RESULTS: Viability and migration capacity of GF and OB were not affected by PDT (for GF: p = 0.48, for OB: p = 0.08 compared to control group) whereas soft laser irradiation only improved cell viability and migration and MB treatment only reduced cell viability and migration. After 72 hours of incubation of both GF and OB, the gaps were almost closed. CONCLUSIONS: In vitro, PDT did not affect viability and migration capacity of GF and OB whereas soft laser treatment only had a positive effect on GF and OB. Therefore, PDT seems to be a safe method in the treatment of periodontal infections without significant side effects.

Is there a Genotoxic Potential of Endodontic Root Materials?

BACKGROUND: Leakage of components from endodontic materials (EM) can occur in case of apical extrusion into the periapical tissue. Therefore, an important prerequisite, besides the mechanical properties of the EM, is a high biocompatibility. In the present study, we elucidated the genotoxic potential of EMs of different base composition by utilizing the -H2AX assay. METHODS: For investigation of the genotoxic potential of EM, supernatants of commercially available EM were prepared and dilutions were applied to human gingival fibroblasts. Non-toxic doses of EM were determined by cell viability assay. For the -H2AX assay, human gingival fibroblasts were incubated with predefined concentrations of the supernatants, which were found not to reduce cell viability. Hydrogen peroxide was utilized as positive control. Cells were fixed 1, 6 and 24 hours after addition of the supernatant to the medium, followed by immunostaining for -H2AX. For scoring of -H2AX foci, automated foci counting was performed in at least 80 cells per experiment and time point. The experiments were repeated at least twice. RESULTS: In contrast to hydrogen peroxide treated cells, no elevated -H2AX levels were detected in cells incubated with the EM supernatants. CONCLUSIONS: Samples treated with EM supernatants showed no elevated levels of -H2AX foci, e.g., no genotoxicity. Therefore, all types of EM seem to meet the standard to be called a biocompatible dental material in terms of genotoxicity, and, therefore, the application seems safe.

Dental age assessment in 6- to 14-year old German children: comparison of Cameriere and Demirjian methods.

BACKGROUND: The aim of the study was to compare two frequently used dental age estimation methods for accuracy. METHODS: A total of 479 panoramic radiographs in age groups 6-14 years from a German population were evaluated. The dental age of 268 boys and 211 girls was assessed by means of the method of Demirjian (1973) and Cameriere (2006) and compared with their actual chronological age. RESULTS: Demirjan's method showed an overestimation of dental age compared to chronological age in all age groups for boys (mean difference -0.16, p = 0.010, range -0.35 to 0.09), age group 9 showed an underestimation. Using the same method for girls (mean difference -0.18, p = 0.008, range -0.45 to 0.13), an overestimation could also be shown in all age groups except for age groups 8 and 13. Results for Cameriere's method showed for boys (mean difference 0.07, p = 0.314, range -1.38 to 3.83) in age groups 6 to 11 an overestimation, but in age groups 12 to14 an underestimation. The results for girls (mean difference 0.08, p = 0.480, range -1.55 to 4.51) showed an overestimation for age groups from 6 to 10, and an underestimation in age groups 11 to 14. CONCLUSIONS: The comparison shows an advantage of Demirjian's method for both genders. While Cameriere's method showed a higher inaccuracy in all age groups, Demirjian's method showed more appropriate results for dental age estimation of the investigated German population. To avoid errors in forensic age estimation and to prevent misidentifications for defendants in criminal processes, further studies of more precise methods for age estimation for the German population are required.

Oral Hygiene and Dietary Habits in Adolescents with Fixed Orthodontic Appliances: A Cross-sectional Study.

OBJECTIVES: Fixed orthodontic appliances (FOAs) may cause a temporary deterioration of oral hygiene with corresponding gingival inflammatory changes. Optimal oral hygiene and dietary changes are essential in order to avoid periodontal inflammation. The present study investigates to what extent the recommendations made by the orthodontist are followed by young patients. MATERIALS AND METHODS: A total of 67 adolescent patients with FOA were examined and interviewed. The control group consisted of 70 patients of the same age who had not undergone any orthodontic treatment. A specific questionnaire (assessing dietary habits, oral hygiene measures) was used and comprehensive oral findings along with oral hygiene status were evaluated. RESULTS: The analysis of the data showed that despite intensive oral hygiene and dietary advice in the patients with FOA, there was no change in diet or oral hygiene habits. There were significantly higher signs of gingival inflammation and amount of dental plaque in FOA patients. Nutritional recommendations and oral hygiene measures for young people with FOA were not adequately enforced. CONCLUSION: The findings indicate that frequent recalls should be scheduled with repeated reinforcement of oral hygiene and dietary modifications in FOA patients.

Penetration Potential of a Silver Diamine Fluoride Solution on Dentin Surfaces. An Ex Vivo Study.

BACKGROUND: Occurrence of open dentinal tubules as a cause of dental hypersensitivity is a very common pnenomenon in patients. The aim of this in vitro study was to assess the effect of a silver diamine fluoride solution (Ag(NH3)2 F) on human dentin samples. METHODS: A total of five fully retained wisdom teeth were selected for this study. The crowns of the teeth were separated from the roots and the occlusal enamel surface was removed. All dentin samples were treated for 60 seconds with phosphoric acid (36%) and rinsed thoroughly to remove the smear layer. Then the desensitizing agent (Riva Star, SDI; 38% Ag(NH3)2 F) was placed according to the manufacturer's instruction. Three dentin samples were prepared for element analysis using an electron beam microprobe analyzer (JEOL JXA 8900RL). The Ag concentrations in the dentin samples were measured in depths ranging from 5 to 40 µm. The other two dentin samples were vertically fractured and accordingly prepared for visualization with SEM (Zeiss DSM). RESULTS: The application of the desensitizing agent on the dentin areas demonstrated an increased Ag concentration (JEOL JXA 8900RL). On the dentin surface an Ag concentration of 1.7 weight % (? 0.7) was measured, but at a depth of 20 µm only 0.3 weight % (± 0.1) were detected. In depths greater than 40 µm the Ag concentration was below the detection limit. The SEM results showed that deposits could be found in a covering on the dentin layer and in the dentinal tubules to a depth of 20 µm. CONCLUSIONS: In this ex vivo study, the effect of silver diamine fluoride on dentin surfaces could be demonstrated. The desensitizing agent formed a film on the dentin surface and in some dentinal tubules deposits were detected. These findings can explain a certain desensitizing effect, but a direct translation to in vivo conditions can only be done with caution.

Influence of E-smoking liquids on human periodontal ligament fibroblasts.

INTRODUCTION: Over the last years, electronic cigarettes (ECs) have become more popular, particularly in individuals who want to give up smoking tobacco. The aim of the present study was to assess the influence of the different e-smoking liquids on the viability and proliferation of human periodontal ligament fibroblasts. METHOD AND MATERIALS: For this study six test solutions with components from ECs were selected: lime-, hazelnut- and menthol-flavored liquids, nicotine, propylene glycol, and PBS as control group. The fibroblasts were incubated up to 96 h with the different liquids, and cell viability was measured by using the PrestoBlue® reagent, the ATP detection and the migration assay. Fluorescence staining was carried out to visualize cell growth and morphology. Data were statistically analyzed by two-tailed one-way ANOVA. RESULTS: The cell viability assay showed that the proliferation rates of the cells incubated with nicotine or the various flavored liquids of the e-cigarettes were reduced in comparison to the controls, though not all reductions were statistically significant. After an incubation of 96 h with the menthol-flavored liquid the fibroblasts were statistically significant reduced (p < 0.001). Similar results were found for the detection of ATP in fibroblasts; the incubation with menthol-flavored liquids (p < 0.001) led to a statistically significant reduction. The cell visualization tests confirmed these findings. CONCLUSION: Within its limits, the present in vitro study demonstrated that menthol additives of e-smoking have a harmful effect on human periodontal ligament fibroblasts. This might indicate that menthol additives should be avoided for e-cigarettes.

In vitro study on dental erosion caused by different vinegar varieties using an electron microprobe.

BACKGROUND: Among health-conscious individuals, including vegetarians, salads dressed with vinegar are frequently consumed. Dental erosion can also be caused by an acidic diet, and occurs with increasing tendency. The aim of this study was to analyze the erosive potential of vinegar varieties on human enamel samples. METHODS: A total of 30 vinegar varieties were selected. Enamel samples were prepared from human wisdom teeth, and the specially prepared enamel slices were incubated with 5 selected vinegars (Bio vinegar, pH = 3.1; raspberry vinegar, pH = 2.7; Condimento Balsamico, pH = 3.95; Ortalli Bianco Modena, pH = 2.7; Vinaigre de Jerez, pH = 2.9) for up to 8 hours. Controls were incubated with a 0.9% sodium chloride solution. The quantitative analysis of CaO, P2O5, F, MgO, Cl, and O in the enamel samples (incubation: 4, 8 hours) in various depths ranging from 7.5 - 105 microm was carried out using an electron probe micro-analyser (Jeol JXA 8900RL). Linear mixed models were fitted to analyze statistically relevant differences between the different vinegars at various depth levels. RESULTS: Incubating the enamel slices with the selected vinegars caused a release of minerals, which was dependent on time and type of vinegar. The vinegar Ortalli Bianco Modena led to a slight loss (1%) of the mineral CaO in a depth up to 20 microm, while the loss of minerals caused by raspberry vinegar in a depth of up to 30 microm was about 20% (4 hours). The greatest loss of the minerals was detected for the Bio Vinegar. After 8 hours incubation, a loss of minerals of about 20% in a depth of 45 microm and in a depth of 60 microm of 16% could be observed. Both, the Bio Vinegar and the raspberry vinegar led to a significantly higher loss of minerals (p < 0.0001) than all other tested vinegars. CONCLUSIONS: In this in vitro study, the erosive potential of different vinegar varieties on human enamel samples could be demonstrated. However, it must be considered that numerous modifying factors influence the enamel surface in vivo; therefore, a direct translation to in vitro conditions can only be done with caution.

Non-cross-linked collagen type I/III materials enhance cell proliferation: in vitro and in vivo evidence.

OBJECTIVE: To analyze Mucograft®(MG), a recently introduced collagen matrix, in vitro and in vivo, and compare it with BioGide®(BG), a well-established collagen membrane, as control. MATERIAL AND METHODS: A detailed analysis of the materials surface and ultra-structure was performed. Cellular growth patterns and proliferation rates of human fibroblasts on MG and BG were analyzed in vitro. In addition, the early tissue reaction of CD-1 mouse to these materials was analyzed by means of histological and histomorphometrical analysis. RESULTS: MG showed a three-fold higher thickness both in dry and wet conditions, when compared to BG. The spongy surface of BG significantly differed from that of MG. Cells showed a characteristic proliferation pattern on the different materials in vitro. Fibroblasts tended to proliferate on the compact layers of both collagens, with the highest values on the compact side of BG. In vivo, at day three both materials demonstrated good tissue integration, with a mononuclear cell sheet of fibroblasts on all surfaces, however, without penetrating into the materials. CONCLUSIONS: The findings of this study showed that MG and BG facilitate cell proliferation on both of their surfaces in vitro. In vivo, these two materials induce a comparable early tissue reaction, while serving as cell occlusive barriers.