Immobilization of peroxidase on textile carrier materials and their application in the bleaching of colored whey.

Textiles represent promising support materials for enzymes. The goal of the present work was to investigate the immobilization of commercial peroxidase on a polyester needle felt and the repeated use in the gentle degradation of norbixin in whey from dairy cheese as a practical application. High enzyme loads were obtained by a 2-step immobilization procedure. First, the number of functional groups on the textile surface was increased by a modification with amino-functional polyvinylamine. Second, the enzyme was immobilized by using 2 types of crosslinking agents. Due to the iron content of peroxidase, inductively coupled plasma-optical emission spectrometry was used for the quantitative determination of the enzyme load on the textile. The enzyme activity was evaluated using common 2,2'-azino-di-(3-ethylbenzthiazoline-6-sulfonic acid) assay for peroxidases. By the variation of enzyme input and crosslinker concentration, a maximal enzyme load of 80 mg/g of textile was achieved, and a maximum specific activity of 57 U/g of textile. For the visualization of the enzyme on the fiber surface, fluorescence microscopy as well as scanning probe microscopy were used. The immobilized peroxidase showed significant activity, even after 50 reuse cycles. In addition, the potential of the new support and enzyme combination in commercial whey bleaching was demonstrated successfully on a 10-L scale.

Fracture incidence of WaveOne Gold files: a prospective clinical study.

AIM: This prospective clinical study evaluated the incidence of instrument fracture observed after single-file root canal treatment of molars using WaveOne Gold instruments. METHODOLOGY: Three standardized, experienced and calibrated specialists treated 750 maxillary and mandibular molars with curvatures less than 45° (2691 root canals) over a 12-month period. All the treatments were performed in a single session. A total of 1104 WaveOne Gold instruments were used, including 38 small, 750 primary, 228 medium and 88 large instruments. Intracanal procedures were performed according to the manufacturer's recommendations, and each instrument was used in a single clinical case. The instruments were examined after their removal from the canal, under an operating microscope at 8× magnification. RESULTS: No fractures were observed in any of the 1104 instruments used. CONCLUSIONS: No fractures of WaveOne Gold reciprocating instruments occurred during root canal preparations performed in maxillary and mandibular molars with curvatures less than 45° when used strictly according to the manufacturer's recommendations and applied in a single clinical case.

Enzymatic epoxidation of cyclohexene by peroxidase immobilization on a textile and an adapted reactor design.

A textile-based reaction system for new peroxidase reactions in non-native media was implemented. The epoxidation of cyclohexene by the commercial peroxidase MaxiBright® was realized with the textile-immobilized enzyme in an adapted liquid-liquid two-phase reactor. A commercially available polyester felt was used as low-price carrier and functionalized with polyvinyl amine. The covalent immobilization with glutardialdehyde lead to an enzyme loading of 0.10 genzyme/gtextile. The textile-based peroxidase shows a high activity retention in the presence of organic media. This catalyst is shown to enable the epoxidation of cyclohexene in various solvents as well as under neat conditions. A model reactor was produced by 3D printing which places the textile catalyst at the interphase between the liquid reaction phase and the product extracting solvent.

The association between smoking and periapical periodontitis: a systematic review.

OBJECTIVES: The purpose of this systematic review was to examine if, in adult patients, the absence or presence of smoking influenced the prevalence of periapical periodontitis (PP). MATERIALS AND METHODS: Databases were searched, and original research manuscripts up to June 2019 were identified by two reviewers. The Newcastle-Ottawa Scale (NOS) was used for risk of bias. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used for certainty in the evidence. A meta-analysis was performed using RevMan 5 software. Risk ratio (RR) was used for the cohort studies, and odds ratio (OR) was used for the case-control studies with 95% confidence interval (CI). RESULTS: All the studies had many covariates and confounding variables. Three longitudinal cohort articles discussed radiographic findings as they related to the prevalence of PP in root-filled teeth. The RR of smoking and the prevalence of PP was 2.11 (95% CI 0.88-5.05, p = 0.09). Nine case-control studies focused on the prevalence of PP and smoking. There was a positive association between smoking and the prevalence of PP with an OR of 2.78 and a 95% confidence interval of 2.23-3.48, with p value < 0.05. The quality of the studies was fair per NOS, and the certainty of the literature assessment was moderate per GRADE. CONCLUSIONS: The current best available evidence suggests that smoking was associated with the prevalence of PP but more studies are needed to report this association in the longitudinal cohort studies. CLINICAL RELEVANCE: Smoking has a positive association with the prevalence of PP.

Evaluation of several instrumentation techniques and irrigation methods on the percentage of untouched canal wall and accumulated dentine debris in C-shaped canals.

AIM: To evaluate the effect of instrumentation using Reciproc Blue (RB; VDW, Munich, Germany) and XP-endo Shaper (XP-S; FKG Dentaire, La Chaux-deFonds, Switzerland) systems on the area of untouched canal wall (AUCW), accumulated hard-tissue debris (AHTD) and the efficacy of three irrigation protocols on percentage reductions (red%) of AHTD within C-shaped canals of mandibular molars. METHODOLOGY: Seventy mandibular molars with C-shaped canals were scanned, matched and assigned to two shaping groups (n = 35): RB and XP-S. Following instrumentation, specimens were triple-matched with respect to the amount of remaining debris and assigned to three irrigation subgroups (n = 10): syringe-and-needle irrigation (SNI), XP-endo Finisher (XP-F; FKG Dentaire) and passive ultrasonic irrigation (PUI). The AUCW% and AHTD% after instrumentation and the red% of AHTD after irrigation were calculated from micro-computed tomography. Data were analysed using comparisons for two groups (RB vs. XP-S) or multiple subgroups followed by pairwise comparison procedures (SNI vs. XP-F vs. PUI) at α = 0.05. RESULTS: For RB and XP-S, 33.04% and 30.45%, respectively, of the canal wall remained untouched (P > 0.05). For both groups, the apical third had larger AUCW% than the coronal third (P < 0.05). Instrumentation with RB left more debris (2.8%) than XP-S (1.1%) (P < 0.05). The PUI and XP-F subgroups had higher mean red% of AHTD than the SNI subgroup; the difference was significant for RB (P < 0.05) but not for XP-S. CONCLUSIONS: Both RB and XP-S systems were associated with similar AUCW after instrumenting C-shaped canals. RB left significantly greater levels of AHTD compared with XP-S. PUI and XP-F irrigation removed more debris than SNI when using the RB system.

Comparative accuracy of the Clearing Technique, CBCT and Micro-CT methods in studying the mesial root canal configuration of mandibular first molars.

AIMS: To compare the accuracy of the clearing technique and cone beam computed tomography (CBCT) in the assessment of root canal configurations using micro-computed tomography (micro-CT) imaging system as the reference standard. METHODOLOGY: Thirty-two mesial roots of mandibular first molars, selected on the basis of micro-CT scans (voxel size: 19.6 µm) and presenting several canal configurations, were evaluated using 2 CBCT scanners (voxels sizes: 120 µm and 150 µm) followed by the clearing technique. Two examiners analysed the data from each method and classified the anatomical configuration of the mesial canal according to Vertucci's system. Data were compared using Fisher's exact and chi-square tests. Reliability for each assessment was verified by the kappa test, and significance level was set at 5%. RESULTS: Kappa value indicated a high level of agreement between the examiners. Detection of type I configurations was significantly lower in cleared teeth (P < 0.05), whilst type II root canals were detected in all specimens by both tests (P > 0.05). In mesial roots with variable anatomical configurations, CBCT and the clearing method were significantly less accurate than the reference standard (P < 0.05). CONCLUSION: Within the tooth population studied, accuracy of identifying mesial root canal configuration was influenced greatly by the evaluation method and the type of anatomy. Detection of type I configurations in cleared teeth was significantly lower, whilst type II configurations were detected in all specimens by both methods. In mesial roots with variable anatomical configurations, neither CBCT nor clearing methods were accurate for detecting the actual root canal anatomy.

Micro-CT evaluation of C-shaped mandibular first premolars in a Brazilian subpopulation.

AIM: To describe morphometric aspects of the internal anatomy of C-shaped mandibular premolars from a Brazilian subpopulation using micro-CT analysis. METHODOLOGY: First mandibular premolars with radicular grooves (n = 123) were scanned using a micro-computed tomography system. After cross-section analysis, 83 specimens were identified with a C-shaped canal and selected for micro-CT analysis. Number and location of canals according to Vertucci's classification, distances between anatomic landmarks, occurrence of apical deltas, furcation canals, prevalence of C-shaped cross-sections at five levels as well as 2-dimensional analysis (Area, perimeter, roundness, aspect ratio, major and minor diameters) were performed for the more prevalent anatomical features. Data were compared statistically using Kruskal-Wallis tests (α = 0.05). RESULTS: The more prevalent anatomical types according to Vertucci's classification were Type I (13%), III (8%), V (37%) and VII (2%). Mean distances from the furcation to the cemento-enamel junction were in the range of 5.36-5.65 mm. Apical deltas and furcation canals were present in 36 (43%) and 27 (33%) specimens, respectively. C-shaped cross-sections were more prevalent at the middle (56%) and apical middle levels (81%). Overall, significant differences were found in the 2-dimensional analyses between single canals at the apical third and buccal and lingual canals of Vertucci's V classification (P < 0.05). CONCLUSIONS: In this Brazilian subpopulation, C-shaped canal configuration of the root canal system was found in 67% of extracted first mandibular premolars with radicular grooves. Vertucci's types I and V were the most prevalent anatomical variations. C-shaped cross-sections were more prevalent in the middle third, and the presence of apical deltas was the most common feature in the apical third.

A comparison of four gutta-percha filling techniques in simulated C-shaped canals.

AIM: To compare four gutta-percha filling techniques in simulated C-shaped canals based on filling quality at three cross-sectional levels, filling time and the apical extrusion of gutta-percha. METHODOLOGY: Forty resin simulated C-shaped canals were constructed and filled using one of four techniques: cold lateral compaction (LC), ultrasonic compaction (UC), single cone with injectable gutta-percha (Obtura II(™) ) (IT) and core-carrier (Thermafil(®) ) (CC). Cross sections were made at 1 (L1), 3 (L3) and 6 (L6) mm from the canal terminus. Areas of gutta-percha, sealer and voids in each cross section were measured using an image analysis system. Data were analysed using a univariate general linear model and post hoc test (Dunnett's T3). Data on time taken to fill canals was evaluated using the Bonferroni post hoc test. RESULTS: CC had more gutta-percha and less sealer compared with IT at L1 (P < 0.05). LC had marginally significantly less gutta-percha than CC at this level (P = 0.049). At level 3 mm, significantly more gutta-percha and less sealer were present in IT compared with LC (P < 0.05). The techniques showed no difference in quality at L6. The time for LC (20.72 min) was three times longer than for both IT (6.11 min) and CC (6.67 min), whereas for UC (26.92 min), it was four times longer (P < 0.001). Finally, the four techniques were not different in the occurrence of apical extrusion of gutta-percha. CONCLUSIONS: The core-carrier technique was the most effective technique when assessed by gutta-percha area in this simulated C-shaped canal.

[New nanofibrous scaffold for corneal tissue engineering]. / Eine neue Nanofaser-Matrix für den kornealen Gewebeersatz.

BACKGROUND: An estimated 10 million people suffer worldwide from vision loss caused by corneal damage. For the worst cases, the only available treatment is transplantation with human donor corneal tissue. However, in numerous countries there is a considerable shortage of corneal tissue of good quality, leading to various efforts to develop tissue substitutes. The present study aims to introduce a nanofibrous scaffold of poly(glycerol sebacate) PGS as a biodegradable implant, for the corneal tissue engineering. MATERIALS AND METHODS: Nanofibrous scaffolds were produced from PGS and poly(ε-caprolactone) (PCL) by a modified electro-spinning process. The biocompatibility of the material was tested in vitro by colorimetric MTT assay on days 3, 5, and 7 to test the cell viability of human corneal endothelium cells (HCEC). To examine a potential immunological reaction of the scaffolds, samples were exposed to mononuclear cells derived from peripheral blood (PBMCs). After an incubation period of 3 days, supernatants were assayed for apoptotic assessment and immunogenic potentials by annexin V FITC//propidium iodide and flow-cytometric analysis. RESULTS: We could successfully demonstrate that cultivation of HCECs on PGS/PCL scaffolds was possible. Compared to day 3, cell density determined by microplate absorbance was significantly higher after 7 days of cultivation (p < 0.0001). According to the MTT data, none of the samples showed toxicity. Apoptotic assessments by FACS analysis showed that no composition stimulated apoptosis or activated PBMCs occurred. All the compositions were inert for native as well as activated T/B/NK cells and monocytes. It can be concluded that leukocytes and their activity was not affected by the scaffolds. CONCLUSION: A tissue-like scaffold mimicking the human stroma could be developed. The results indicate that PGS/PCL scaffolds could be considered as ideal candidates for corneal tissue engineering as they are biocompatible in contact to corneal endothelial cells and blood cells.

Three-dimensional morphological analysis of C-shaped canals in mandibular first premolars in a Chinese population.

AIM: To investigate and compare the unique anatomical features and positioning of C-shaped canals in mandibular first premolars with and without radicular grooves in a Chinese population. METHODOLOGY: A total of 327 extracted mandibular first premolars including 146 with radicular grooves and 181 without radicular grooves from a Chinese population were scanned by µCT-50 or µCT-80. After reconstruction, canal systems were classified according to a modified Vertucci method and the anatomical features evaluated. The data were analysed by one-way anova test, Chi-square test and Fisher's exact test (P < 0.05). RESULTS: Of 146 mandibular first premolars with a radicular groove, 97 had C-shaped canals, the predominant anatomical canal type being Vb (P < 0.001), which was characterized by an oval canal in the coronal part and a semicolon or continuous C-shape beneath the groove. Of the 181 mandibular first premolars without a radicular groove, no C-shaped canal system was observed, and the percentage of Ia (97.8%) was significantly higher than those of other types (P < 0.001). CONCLUSION: In teeth from a Chinese population, mandibular first premolars with radicular grooves had a high incidence of C-shaped canal systems with anatomical variations along the root.

Alteration in the inherent metallic and surface properties of nickel-titanium root canal instruments to enhance performance, durability and safety: a focused review.

The expanded use of nickel-titanium (NiTi) rotary instruments in root canal procedures has led to the development of a wide variety of shapes, designs and applications. Root canal anatomy has not changed, however, and the same challenges exist in both initial treatment and the revision of unacceptable treatment. These challenges include application with high levels of achievement and low to no levels of adverse effects, such as instrument fracture, root canal wall ledging, dentine wall perforation and so forth. To that end, many manufacturers have been seeking ways to alter the presently available and wide range of root canal instrument designs, with a focus on altering the surface of the alloy or altering the alloy microstructure with post-machining or post-twisting heat treatment. This focused review will address the impact that these modifications have had on instrument flexibility, resistance to cyclic fatigue and cutting efficiency.

The efficacy of pre-operative oral medication of lornoxicam and diclofenac potassium on the success of inferior alveolar nerve block in patients with irreversible pulpitis: a double-blind, randomised controlled clinical trial.

AIM: To determine the effect of administration of pre-operative lornoxicam (LNX) or diclofenac potassium (DP) on the success of inferior alveolar nerve blocks (IANB) in patients with irreversible pulpitis in a double-blind randomised controlled trial. METHODOLOGY: One hundred and fourteen patients with irreversible pulpitis of a mandibular posterior tooth participated. Patients indicated their pain scores on a Heft Parker visual analogue scale, after which they were randomly divided into three groups (n = 38). The subjects received identical capsules containing 8 mg LNX, 50 mg DP or cellulose powder (placebo, PLAC), 1 h before administration of IANB with 2% lidocaine containing 1 : 200 000 epinephrine. Lip numbness was assessed after 15 min, following which the teeth were tested with cold spray and their responses (negative or positive) were recorded. Access cavities were then prepared and success of IANB was defined as the absence of pain during access preparation and root canal instrumentation. The data were analysed using chi-squared tests. RESULTS: The percentages of teeth giving a negative response to cold test were 42.8% (PLAC), 78.5% (LNX) and 67.8% (DP), with no significant differences amongst the groups (P > 0.05). The success rates for the IANB in descending order were 71.4% (LNX), 53.5% (DP) and 28.5 (PLAC). A significant (P < 0.001) difference was found between the LNX and the PLAC groups only. CONCLUSIONS: Pre-operative administration of LNX significantly improved the efficacy of IANB in patients with irreversible pulpitis, whilst the effect of pre-medication with DP was not significantly different from the PLAC.

Analysis of the gutta-percha filled area in C-shaped mandibular molars obturated with a modified MicroSeal technique.

AIM: To analyse the gutta-percha filled area of C-shaped molar teeth root filled with the modified MicroSeal technique with reference to the radiographic features and the C-shaped canal configuration. METHODOLOGY: Twenty-three mandibular second molar teeth with C-shaped roots were classified according to their radiographic features as: type I--merging, type II--symmetrical and type III--asymmetrical. The canals were root filled using a modified technique of the MicroSeal system. Horizontal sections at intervals of 600 mum were made 1 mm from the apex to the subpulpal floor level. The percentage of gutta-percha area from the apical, middle and coronal levels of the radiographic types was analysed using the Kruskal-Wallis test. Complementary analysis of the C-shaped canal configurations (C1, C2 and C3) determined from cross-sections from the apical third was performed in a similar way. RESULTS: No significant differences were found between the radiographic types in terms of the percentage of gutta-percha area at any level (P > 0.05): apical third, type I: 77.04%, II: 70.48% and III: 77.13%, middle third, type I: 95.72%, II: 93.17%, III: 91.13% and coronal level, type I: 98.30%, II: 98.25%, III: 97.14%. Overall, the percentage of the filling material was lower in the apical third (P < 0.05). No significant differences were found between the C-shaped canal configurations apically; C1: 72.64%, C2: 79.62%, C3: 73.51% (P > 0.05). CONCLUSIONS: The percentage of area filled with gutta-percha was similar in the three radiographic types and canal configuration categories of C-shaped molars. These results show the difficulty of achieving predictable filling of the root canal system when this anatomical variation exists. In general, the apical third was less completely filled.

Dislocation resistance of ProRoot Endo Sealer, a calcium silicate-based root canal sealer, from radicular dentine.

AIM: To examine the dislocation resistance of three root canal sealers from radicular dentine with and without immersion in a simulated body fluid (SBF), using a modified push-out test design that produced simulated canal spaces of uniform dimensions under identical cleaning and shaping conditions. METHODOLOGY: Sixty single-rooted caries-free human canine teeth were used. Standardized simulated canal spaces were created using 0.04 taper ProFile instruments along the coronal, middle and apical thirds of longitudinal tooth slabs. Following NaOCl/ethylenediamine tetra-acetic acid cleaning, the cavities were filled with ProRoot Endo Sealer, AH Plus Jet or Pulp Canal Sealer. After setting, half of the cavities were tested with a fibre-optic light-illuminated push-out testing device. The rest were immersed in SBF for 4 weeks before push-out evaluation. Failure modes were examined with stereomicroscopy and field emission (FE)-scanning electron microscopy. RESULTS: Location of the sealer-filled cavities did not affect push-out strengths. ProRoot Endo Sealer exhibited higher push-out strengths than the other two sealers particularly after SBF storage (P < 0.001). Failure modes were predominantly adhesive and mixed for Pulp Canal Sealer and AH Plus Jet, and predominantly cohesive for ProRoot Endo Sealer. Spherical amorphous calcium phosphate-like phases that spontaneously transformed into apatite-like phases were seen in the fractured specimens of ProRoot Endo Sealer after SBF storage. CONCLUSIONS: When tested in bulk without a main core, both 'sealer type' and 'SBF storage' were significant in affecting push-out results. The ProRoot Endo Sealer demonstrated the presence of spherical amorphous calcium phosphate-like phases and apatite-like phases (i.e. ex vivo bioactivity) after SBF storage.

Microscopic appearance and apical seal of root canals filled with gutta-percha and ProRoot Endo Sealer after immersion in a phosphate-containing fluid.

AIM: To investigate the sealing quality of ProRoot Endo Sealer, a calcium silicate-based sealer and its morphologic characteristics after immersion in a phosphate-containing fluid (PCF). METHODOLOGY: Single-rooted canals were filled with gutta-percha and either ProRoot Endo Sealer or two commercially available zinc oxide eugenol (ZOE)-based and epoxy resin-based sealers. The sealers were allowed to set for 6 days and the filled teeth were immersed in PCF for 24 h before fluid leakage evaluation. After initial leakage evaluation at the 7th day, each filled root was restored and reimmersed in PCF for 28 days before the second phase of leakage evaluation at 35 days. Cryofractured specimens of additional teeth filled with the three sealers were examined using scanning electron microscopy after immersion in PCF for the two periods. RESULTS: One-way repeated measures anova and Tukey test revealed significant differences between the ZOE-based sealer at 35 days and the calcium silicate-based sealer at 35 days (P < 0.001), and between the ZOE-based sealer at 7 days and the calcium silicate-based sealer at 35 days (P = 0.001). No difference was found between the epoxy resin-based sealer and the calcium silicate-based sealer after both storage periods. Cryofractured calcium silicate-based sealer specimens demonstrated apatite-like crystalline deposits along the apical and middle thirds of the canal walls via transformation from amorphous calcium phosphate-like precursors. CONCLUSIONS: ProRoot Endo Sealer is comparable in sealing quality to the epoxy resin-based sealer and seals better than the ZOE-based sealer after immersion in PCF. The calcium silicate-based sealer also demonstrates ex vivo bioactivity when it comes into contact with phosphate ions.

Modification of the morphology of P(S-b-EO) templated thin TiO2 films by swelling with PS homopolymer.

For the controlled modification of sol-gel-templated polymer nanocomposites, which are transferred to a nanostructured, crystalline TiO2 phase by a calcination process, the addition of a single homopolymer was investigated. For the preparation, the homopolymer polystyrene (PS) is added in different amounts to the diblock copolymer P(S-b-EO) acting as a templating agent. The homopolymer/diblock copolymer blend system is combined with sol-gel chemistry to provide and attach the TiO2 nanoparticles to the diblock copolymer. So-called good-poor solvent-pair-induced phase separation leads to the formation of nanostructures by film preparation via spin coating. The fabricated morphologies are studied as a function of added homopolymer before and after calcination with atomic force microscopy, field emission scanning electron microscopy, and grazing incidence small-angle X-ray scattering. The observed behavior is discussed in the framework of controlling the block copolymer morphologies by the addition of homopolymers. At small homopolymer concentrations, the increase in homopolymer concentration changes the structure size, whereas at high homopolymer concentrations, a change in morphology is triggered. Thus, the behavior of a pure polymer system is transferred to a more complex hybrid system.

Nanowear on polymer films of different architecture.

In this paper, we describe atomic force microscope (AFM) friction experiments on different polymers. The aim was to analyze the influence of the physical architecture of the polymer on the degree and mode of wear and on the wear mode. Experiments were carried out with (1) linear polystyrene (PS) and cycloolefinic copolymers of ethylene and norbornene, which are stabilized by entanglements, (2) mechanically stretched PS, (3) polyisoprene-b-polystyrene diblock copolymers, with varying composition, (4) brush polymers consisting of a poly(methyl methacrylate) (PMMA) backbone and PS side chains, (5) PMMA and PS brushes grafted from a silicon wafer, (6) plasma-polymerized PS, and (7) chemically cross-linked polycarbonate. For linear polymers, wear depends critically on the orientation of the chains with respect to the scan direction. With increasing cross-link density, wear was reduced and ripple formation was suppressed. The cross-linking density was the dominating material parameter characterizing wear.

Biodegradable porous calcium polyphosphate scaffolds for the three-dimensional culture of dental pulp cells.

AIM: To develop a three-dimensional culture model of human dental pulp cells (DPCs) with biodegradable porous calcium polyphosphate (CPP) scaffolds. METHODOLOGY: Human DPCs were isolated from three donors. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to evaluate the cytotoxicity of CPP compared with hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP). Values were analysed using unpaired t-tests. Cells were seeded onto porous CPP scaffolds with pore sizes in the range of 200-300 microm. The nature of cellular adaptation in the three-dimensional culture model was then evaluated visually by scanning electronic microscopy (SEM) and confocal laser scanning microscopy (CLSM). The apoptotic property of cells on the scaffolds was also assessed by DNA staining with CLSM. RESULTS: The cytotoxicity assay indicated that there was no significant difference between CPP and HA for each donor's original cells (P>0.05). Calcium polyphosphate had no cytotoxic effect on DPCs, whilst SEMs showed that cells successfully adhered to CPP scaffolds and spread amongst pores. On the cell surface, fine processes and matrix secretory granules were found. Confocal laser scanning microscopy showed that cells took on a three-dimensional structure with signs of vitality. CONCLUSION: Porous CPP scaffolds are promising for the establishment of a three-dimensional culture model of DPCs.