Novel Confocal-Laser-Scanning-Microscopy and conventional measures investigating eroded dentine following dentifrice dab-on and brushing abrasion

Objectives To validate novel non-contacting Confocal-Laser-Scanning-Microscopy (CLSM) methodology with conventional Contacting Profilometry (CP) measures investigating brushing or dab-on of stannous-fluoride dentifrice on early aggressive dentine erosion. Methods 75 polished human dentine samples were prepared and eroded in agitated 6% citric acid then randomly allocated into 5 intervention groups; artificial saliva control (1); controlled use of a pressure sensitive counter-rotating oscillatory powered toothbrush with sodium-fluoride NaF (2) or stannous-fluoride SnF2 (3), and dab-on application of NaF (4) or SnF2 (5). Samples underwent three cycles of intervention and 2-min agitated 6 % citric acid challenges. CLSM images were taken and 3D reconstructions produced of step height using a developed software algorithm. In addition, 20 % samples were randomised and profiled using CP to measure step height and surface roughness. Vickers's diamond micro-hardness testing was carried out on all samples. Results Comparing CLSM and CP; Pearson correlation was 0.77 and Intra-class correlation 0.81 (p = 0.01). There were no significant statistical differences in step height between groups using both CLSM and CP. From baseline, SnF2 brushing (3) increased micro-hardness more than control (1) (p = 0.03), NaF (4) and SnF2 dab-on (5) (p ≤ 0.001), and increased surface roughness more than control (p = 0.02), NaF brushing (2) and NaF dab-on (4) (p ≤ 0.017). Dab-on of SnF2 (5) produced rougher surfaces than control (1) (p = 0.014) and reduced hardness compared with NaF brushing (p = 0.04). Conclusions Good agreement and correlation exists between CLSM and CP measures in dentine. There were no significant differences in surface loss after interventions between groups. Compared with control, SnF2 application increased dentine surface roughness and SnF2 controlled powered brushing application increased dentine hardness, likely caused by exposure of uneroded dentine. Clinical significance Isosurfaces produced using CLSM can be used to represent dentine step height loss. They show good correlation and agreement with conventional CP measures, following early aggressive erosion-abrasion cycles of dentine. The CLSM and computer algorithm therefore provides an accurate, standalone and non-contacting three-dimensional measurement of early dentine wear. Stannous-fluoride brushing, and dab-on application offer no benefits following early aggressive erosion in dentine. To reduce dentine wear, limiting erosive challenges and avoiding brushing post-erosion is advised

The Banner of the Sea : The Scranton Truth\u27s Prize Song

https://digitalcommons.library.umaine.edu/mmb-vp/3030/thumbnail.jp

Fogeredetű őssejtek izolálása és jellemzése = Isolation and characterisation of postnatal stem cells of dental origin

Kutatásainkhoz a K61543 kutatási pályázatmellé elnyertük a IN67250 nemzetközi kiegészítő támogatást is, így beszámolónk ezek összefoglaló zárójelentése. Vizsgálataink célja emberi fogbélből és parodontális ligamentumból származó őssejtek izolálása és jellemzése, in vitro modell-rendszerek és eljárások kidolgozása a fogeredetű, és így potenciálisan a fogak és a parodontális szövetek részleges vagy teljes regenerációjára felhasználható őssejtek azonosítására, izolálására és fejlődési, differenciálódási képességeik meghatározására, illetve ectodermális sejtekkel való kölcsönhatásaik jellemzésére. Munkánk során emberi fogak pulpájából (dental pulp stem cell=DPSC) és a parodontális ligamentumból (periodontal ligament stem cells=PDLSC) illetve emberi nyálmirigyekből (PTHSG) preparáltunk pluripotens őssejteket tartalmazó sejtkultúrákat. Ezen kultúrákat molekuláris és sejtbiológiai módszerekkel jellemeztük, a sejteket különböző irányú differenciálódásra / transdifferenciálódásra bírtuk. Az osteogén differenciálódás mellett ki kell emelnünk mind a DPSC, mind a PDLSC sejtek képességét a neuronális differenciálódásra az általunk kidolgozott három lépésből álló protokoll mellett. Fentieken túl egy új állatkísérletes tesztrendszert dolgoztunk ki az osseointegráció, illetve a parodontális ligamentum és a fogbél regenerációjának tanulmányozására. Mindezek megalapozzák további ilyen irányú kutatásainkat, az emberi fogeredetű sejtek in vivo regenerációs alkalmazásának kidolgozására. | The originally supported K61543 research grant received additional support by IN67250, which is a supplementary international extension of the same project. Therefore, this is a joint report of the twin grants. The purpose of our study was to isolate and characterize human stem cells from dental pulp and periodontal ligament, to develop in vitro model systems and processes, for identification of stem cells, which have the potential for full or partial regeneration dental and periodontal tissues. On the course of our work we prepared cultures containing pluripotent postnatal stem cells from the dental pulp (dental pulp stem cell=DPSC), from the periodontal ligament (periodontal ligament stem cells=PDLSC), and from the salivary glands (PTHSG). We characterized these cultures and developed methods for their differentiation / transdifferentiation in vitro. Besides the osteogenic differentiation we must highlight the potency of both DPSC and PDLSC cells for neuronal differentiation when our newly developed three step protocol is used. Moreover we also developed and in vivo animal test model for studying osseointegration, periodontal and pulp regeneration. These results will give the foundation of our future work towards the application of human stem cells of dental origin in biological regeneration of damaged tissues

Downregulation of FGF Signaling by Spry4 Overexpression Leads to Shape Impairment, Enamel Irregularities, and Delayed Signaling Center Formation in the Mouse Molar.

FGF signaling plays a critical role in tooth development, and mutations in modulators of this pathway produce a number of striking phenotypes. However, many aspects of the role of the FGF pathway in regulating the morphological features and the mineral quality of the dentition remain unknown. Here, we used transgenic mice overexpressing the FGF negative feedback regulator Sprouty4 under the epithelial keratin 14 promoter (K14-Spry4) to achieve downregulation of signaling in the epithelium. This led to highly penetrant defects affecting both cusp morphology and the enamel layer. We characterized the phenotype of erupted molars, identified a developmental delay in K14-Spry4 transgenic embryos, and linked this with changes in the tooth developmental sequence. These data further delineate the role of FGF signaling in the development of the dentition and implicate the pathway in the regulation of tooth mineralization. © 2019 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research

Comparison of three strip-type tests and two laboratory methods for salivary buffering analysis

This study evaluated the correlation between three strip-type, colorimetric tests and two laboratory methods with respect to the analysis of salivary buffering. The strip-type tests were saliva-check buffer, Dentobuff strip and CRT® Buffer test. The laboratory methods included Ericsson's laboratory method and a monotone acid/base titration to create a reference scale for the salivary titratable acidity. Additionally, defined buffer solutions were prepared and tested to simulate the carbonate, phosphate and protein buffer systems of saliva. The correlation between the methods was analysed by the Spearman's rank test. Disagreement was detected between buffering capacity values obtained with three strip-type tests that was more pronounced in case of saliva samples with medium and low buffering capacities. All strip-type tests were able to assign the hydrogencarbonate, di-hydrogenphosphate and 0.1% protein buffer solutions to the correct buffer categories. However, at 0.6% total protein concentrations, none of the test systems worked accurately. Improvements are necessary for strip-type tests because of certain disagreement with the Ericsson's laboratory method and dependence on the protein content of saliv

Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs

A new scoring system, the Basic Erosive Wear Examination (BEWE), has been designed to provide a simple tool for use in general practice and to allow comparison to other more discriminative indices. The most severely affected surface in each sextant is recorded with a four level score and the cumulative score classified and matched to risk levels which guide the management of the condition. The BEWE allows re-analysis and integration of results from existing studies and, in time, should initiate a consensus within the scientific community and so avoid continued proliferation of indices. Finally, this process should lead to the development of an internationally accepted, standardised and validated index. The BEWE further aims to increase the awareness of tooth erosion amongst clinicians and general dental practitioners and to provide a guide as to its management