BMSC-HNC Interaction: Exploring Effects on Bone Integrity and Head and Neck Cancer Progression.

In recent research, the tumor microenvironment has been shown to attract mesenchymal stromal cells (MSCs), which is of particular interest due to its implications for cancer progression. The study focused on understanding the interaction between bone marrow-derived MSCs (BMSCs) and head and neck cancer (HNC) cells. This interaction was found to activate specific markers, notably the osteogenic marker alkaline phosphatase and the oncogene Runx2. These activations corresponded with the release of collagenase enzymes, MMP9 and MMP2. To gain insights into bone resorption related to this interaction, bovine bone slices were used, supporting the growth of "heterogeneous spheroids" that contained both BMSCs and HNC cells. Through scanning electron microscopy and energy-dispersive X-ray (EDX) analysis, it was observed that these mixed spheroids were linked to a notable increase in bone degradation and collagen fiber exposure, more so than spheroids of just BMSCs or HNC cells. Furthermore, the EDX results highlighted increased nitrogen content on bone surfaces with these mixed clusters. Overall, the findings underscore the significant role of BMSCs in tumor growth, emphasizing the need for further exploration in potential cancer treatment strategies.

Randomized Clinical Split-Mouth Study on Partial Ceramic Crowns Luted with a Self-adhesive Resin Cement with or without Selective Enamel Etching: Long-Term Results after 15 Years.

PURPOSE: This follow-up of a randomized clinical split-mouth study aimed to investigate the influence of selective enamel etching on the long-term clinical performance of partial ceramic crowns (PCCs) luted with a self-adhesive resin cement. MATERIALS AND METHODS: 43 patients received two PCCs (Vita Mark II; Cerec 3D) each for the restoration of extensive lesions with multiple cusp coverage, inserted with a self-adhesive resin cement (RelyX Unicem, RXU). Using a split-mouth design, one PCC received additional selective enamel etching (RXU+E) and one did not (RXU-E). Patients were clinically evaluated at baseline and after up to 15 years (median observation period 176 months) using modified USPHS and FDI criteria. The data were analyzed non-parametrically (chi-squared tests, α = 0.05). Clinical survival of all restorations after 15 years was evaluated using the Kaplan-Meier analysis. RESULTS: After 15 years, 19 patients were available for clinical assessment (recall rate: 56%). Kaplan-Meier analysis showed a cumulative survival of 78.1% for RXU+E and of 42.9% for RXU-E, indicating a significantly higher survival rate for RXU+E (p = 0.004). Regarding the clinical performance of PCCs available for the 15-year evaluation, no statistically significant differences were found between RXU+E and RXU-E using modified USPHS and FDI criteria. Both groups revealed significant deterioration over time regarding surface luster, marginal adaptation, and marginal discoloration. RXU+E resulted in significantly inferior anatomic form over time and a significant improvement in post-operative hypersensitivity compared to baseline. CONCLUSION: For posterior PCCs, selective enamel etching can be recommended based on higher survival rates after 15 years. Clinically, deterioration due to aging is similar in both groups.

Randomized clinical split-mouth study on a novel self-adhesive bulk-fill restorative vs. a conventional bulk-fill composite for restoration of class II cavities - results after three years.

OBJECTIVES: This randomized prospective split-mouth study evaluated the clinical performance of a novel, tooth-colored, self-adhesive bulk-fill restorative (SABF, 3M) for restoration of class II cavities as compared to a conventional bulk-fill composite (Filtek One, 3M; FOBF) over 36 months. The null-hypothesis was that both materials perform equally regarding clinical success and performance according to the FDI clinical criteria and scoring system. METHODS: 30 patients received one SABF and one FOBF restoration each. For FOBF, Scotchbond Universal (3M) was used as adhesive (self-etch mode), whereas SABF was applied without adhesive. Two blinded examiners evaluated the restorations at baseline, 24 and 36 months using FDI criteria. Data were analyzed non-parametrically (χ2-tests; α=0.05). RESULTS: 29 patients were available for the 24- and 36-month examinations. Clinical success rate was 96.6% for both materials at 36-mo (one restoration failure due to secondary caries each). All other restorations revealed clinically acceptable FDI scores at all recalls. FOBF performed significantly better than SABF at all time points regarding surface lustre (p<0.001) and color match and translucency (p<0.001) and regarding marginal staining at 36-months (p=0.008). Marginal staining and marginal adaptation deteriorated significantly over time for both materials (both p<0.001). CONCLUSIONS: The null-hypothesis could only partially be rejected. Both materials performed similarly regarding clinical success and performance within 36 months of clinical service, but SABF exhibited significantly inferior, but clinically fully acceptable esthetic properties as compared to FOBF. Both restorative materials showed clinically fully acceptable results over 36 months of clinical service and thus may be recommended for clinical use. CLINICAL SIGNIFICANCE: The novel tooth-colored self-adhesive bulk-fill restorative exhibited clinically fully acceptable results over 36 months of clinical service, similarly to a conventional bulk-fill restorative used with a universal adhesive, but with slight shortcomings in esthetic properties. Therefore, both restorative materials may be recommended for clinical use.

Potential Involvement of Extracellular Citrate in Brain Tumor Progression.

Brain tissue is known to have elevated citrate levels, necessary to regulate ion chelation, neuron excitability, and are also necessary for the supply of necessary energy substrates to neurons. Importantly, citrate also acts as a central substrate in cancer metabolism. Recent studies have shown that extracellular citrate levels in the brain undergo significant changes during tumor development and may play a dual role in tumor progression, as well as cancer cell aggressiveness. In the present article, we review available literature describing changes of citrate levels in brain tissue, blood, and cerebrospinal fluid, as well as intracellular alterations during tumor development before and after metastatic progression. Based on the available literature and our recent findings, we hypothesize that changes in extracellular citrate levels may be related to the increased consumption of this metabolite by cancer cells. Interestingly, cancerassociated cells, including reactive astrocytes, might be a source of citrate. Extracellular citrate uptake mechanisms, as well as potential citrate synthesis and release by surrounding stroma, could provide novel targets for anti-cancer treatments of primary brain tumors and brain metastases.

One-year results of a novel self-adhesive bulk-fill restorative and a conventional bulk-fill composite in class II cavities-a randomized clinical split-mouth study.

OBJECTIVES: In the context of the phase-down of amalgam, development of easily applicable, permanent restorative materials is of high clinical interest. Aim of this study was to evaluate the clinical performance of a novel, tooth-colored, self-adhesive bulk-fill restorative (SABF, 3M Oral Care) and a conventional bulk-fill composite (Filtek One, 3M Oral Care; FOBF) for restoring class II cavities. The null-hypothesis tested was that both materials perform similar regarding clinical performance. MATERIALS AND METHODS: In this randomized split-mouth study, 30 patients received one SABF and one FOBF restoration each. Scotchbond Universal (3M Oral Care) was used as adhesive for FOBF (self-etch mode), while SABF was applied directly without adhesive. Restorations were evaluated by two blinded examiners at baseline, 6 months and 12 months employing FDI criteria. Non-parametric statistical analyses and χ2-tests (α = 0.05) were applied. RESULTS: Thirty patients (60 restorations) were available for the 6- and 12-month recalls exhibiting 100% restoration survival. All restorations revealed clinically acceptable FDI scores at all time points and for all criteria. Only regarding esthetic properties, FOBF performed significantly better than SABF regarding surface lustre (A1) and color match and translucency (A3) at all time points and marginal staining (A2b) at 12 months. CONCLUSIONS: The null-hypothesis could not be rejected. Both materials performed similarly regarding clinical performance within the first year of clinical service. SABF exhibited slightly inferior, but clinically fully acceptable esthetic properties as compared to FOBF. CLINICAL RELEVANCE: Within the limitations of this study, the self-adhesive bulk-fill restorative showed promising results and may be recommended for clinical use.

Randomized clinical split-mouth study on the performance of CAD/CAM-partial ceramic crowns luted with a self-adhesive resin cement or a universal adhesive and a conventional resin cement after 39 months.

Objectives To determine the clinical performance of partial ceramic crowns (PCCs) luted with a conventional resin cement combined with a universal adhesive without or with selective enamel etching or luted with a self-adhesive resin cement. Methods In a split-mouth design, each three CAD/CAM-PCCs (Vita Mark II, Cerec) were placed in 50 patients. Two PCCs were luted with a conventional resin cement (RelyX Ultimate) combined with a universal adhesive (Scotchbond Universal) without (SB-E) or with (SB+E) selective enamel etching. The third PCC was luted with a self-adhesive resin cement (RelyX Unicem 2; RXU). Chi-square tests (α≤0.05) were applied. Based on clinical failures (complete debonding or need for replacement of the restorations), Kaplan-Meier survival analysis was performed. Results 31 patients were evaluated clinically using FDI criteria at 39 months. Clinically acceptable results were detected over time, except for "fracture of material and retention" (inacceptable fractures and debondings). Within materials, statistically significant differences (p ≤ 0.003) between baseline and 39 months were found for "marginal adaptation" and "marginal staining". At 39-month, SB+E and SB-E showed significantly better results compared to RXU in "marginal adaptation"(p ≤ 0.021) and "marginal staining"(p ≤ 0.013). Kaplan-Meier analysis showed higher survival rates after 39 months for SB+E (96%) and SB-E (88%) compared to RXU (69%) with statistically significant differences between RXU vs. SB-E (p = 0.022) and RXU vs. SB+E (p ≤ 0.001). Conclusions After 39-months, PCCs luted with the self-adhesive resin cement exhibited a statistically significant inferior survival rate compared to restorations luted with the conventional resin cement combined with a universal adhesive without or with selective enamel etching. Clinical significance Currently, self-adhesive resin cements cannot be recommended for luting partial ceramic crowns. However, the standard adhesive luting procedure comprising a universal adhesive and luting composite yielded good clinical results for more than 3 years irrespectively of application of a selective enamel etching step.

Cancer-associated cells release citrate to support tumour metastatic progression.

Citrate is important for lipid synthesis and epigenetic regulation in addition to ATP production. We have previously reported that cancer cells import extracellular citrate via the pmCiC transporter to support their metabolism. Here, we show for the first time that citrate is supplied to cancer by cancer-associated stroma (CAS) and also that citrate synthesis and release is one of the latter's major metabolic tasks. Citrate release from CAS is controlled by cancer cells through cross-cellular communication. The availability of citrate from CAS regulated the cytokine profile, metabolism and features of cellular invasion. Moreover, citrate released by CAS is involved in inducing cancer progression especially enhancing invasiveness and organ colonisation. In line with the in vitro observations, we show that depriving cancer cells of citrate using gluconate, a specific inhibitor of pmCiC, significantly reduced the growth and metastatic spread of human pancreatic cancer cells in vivo and muted stromal activation and angiogenesis. We conclude that citrate is supplied to tumour cells by CAS and citrate uptake plays a significant role in cancer metastatic progression.

Micromorphology of the Adhesive Interface of Self-Adhesive Resin Cements to Enamel and Dentin.

Interfaces between dentin, enamel and luting agents were characterized using low vacuum Scanning Electron Microscopy (SEM). After smear layer creation, one of three luting agents (RelyX Unicem 2, Clearfil SA Cement and Panavia F 2.0/ED Primer II) was applied on 60 enamel-dentin specimens and dual-cured or self-cured. Specimens were polished (Experiment 1) and subsequently demineralized and deproteinized (Experiment 2). Adhesive interfaces were analyzed (low vacuum SEM, ×3000). Presence of an interdiffusion zone, tag-like structures (dentin) and marginal gaps (enamel) were assessed. Non-parametrical tests (χ2-test, α = 0.05) were performed. The first null-hypothesis was that the adhesive interface micromorphology between enamel and dentin and self-adhesive resin cements (SARCs) is similar with conventional resin cement used with a self-etch adhesive (CRC+SE). The second null-hypothesis was that the micromorphology is not influenced by curing modes. Interdiffusion zones and tag-like structures (dentin) were observed more frequently for CRC+SE compared to SARCs. For each luting agent, there was a non-significant (p > 0.05) tendency for interdiffusion zone and tag-like structures detectable in more specimens after self-curing compared to dual-curing. Marginal gaps (enamel) were found only for SARCs. The first null-hypothesis was not rejected fully: Tag-like structures and interdiffusion zones in dentin were found for CRC+SE and SARCs. The second null-hypothesis was not rejected.

Influence of selective caries excavation on marginal penetration of class II composite restorations in vitro.

Selective caries excavation may support pulp preservation. This in vitro study investigated the influence of selective removal of demineralized dentin on marginal integrity of composite restorations as determined by dye penetration. Dentinal caries-like lesions were produced in the approximal surfaces of 40 extracted human molars (ethylenediaminetetraacetate, 0.5 M, 96 h). The following test procedures were established: complete excavation, selective excavation, and caries-free control. Two class II cavities with enamel at the cervical margins were prepared per tooth and demineralization volume was determined by micro-computed tomography for the purpose of a stratified distribution to receive complete excavation or selective excavation. After complete or selective excavation (30 cavities each), adhesive composite restorations were placed. Cavities without demineralized dentin (20 cavities) served as control. The marginal integrity of restorations was evaluated by dye penetration with and without thermocycling or mechanical loading. Results were analyzed by non-parametrical statistical tests (Mann-Whitney U Test) with an α = 0.05 level of significance. Dye penetration did not differ significantly among completely excavated, selectively excavated, or undemineralized teeth, but was increased by thermocycling and mechanical loading in all experimental groups. Selective caries removal did not increase marginal penetration in class II restorations. The presence of remaining demineralized dentin surrounded by sound dentin did not impair marginal integrity of restorations with margins placed in sound enamel.

hBMSC-Derived Extracellular Vesicles Attenuate IL-1ß-Induced Catabolic Effects on OA-Chondrocytes by Regulating Pro-inflammatory Signaling Pathways.

Background: Human bone marrow-derived mesenchymal stromal cells (hBMSCs) provide a promising therapeutic approach in the cell-based therapy of osteoarthritis (OA). However, several disadvantages evolved recently, including immune responses of the host and regulatory hurdles, making it necessary to search for alternative treatment options. Extracellular vesicles (EVs) are released by multiple cell types and tissues into the extracellular microenvironment, acting as message carriers during intercellular communication. Here, we investigate putative protective effects of hBMSC-derived EVs as a cell-free approach, on IL-1ß-stimulated chondrocytes obtained from OA-patients. Methods: EVs were harvested from the cell culture supernatant of hBMSCs by a sequential ultracentrifugation process. Western blot, scanning electron microscopy (SEM), and nanoparticle tracking analysis (NTA) were performed to characterize the purified particles as EVs. Intracellular incorporation of EVs, derived from PHK26-labeled hBMSCs, was tested by adding the labeled EVs to human OA chondrocytes (OA-CH), followed by fluorescence microscopy. Chondrocytes were pre-stimulated with IL-1ß for 24 h, followed by EVs treatment for 24 h. Subsequently, proliferation, apoptosis, and migration (wound healing) were analyzed via BrdU assay, caspase 3/7 assay, and scratch assay, respectively. With qRT-PCR, the relative expression level of anabolic and catabolic genes was determined. Furthermore, immunofluorescence microscopy and western blot were performed to evaluate the protein expression and phosphorylation levels of Erk1/2, PI3K/Akt, p38, TAK1, and NF-κB as components of pro-inflammatory signaling pathways in OA-CH. Results: EVs from hBMSCs (hBMSC-EVs) promote proliferation and reduce apoptosis of OA-CH and IL-1ß-stimulated OA-CH. Moreover, hBMSC-EVs attenuate IL-1ß-induced reduction of chondrocyte migration. Furthermore, hBMSC-EVs increase gene expression of PRG4, BCL2, and ACAN (aggrecan) and decrease gene expression of MMP13, ALPL, and IL1ß in OA-CH. Notably, COL2A1, SOX9, BCL2, ACAN, and COMP gene expression levels were significantly increased in IL-1ß+ EV groups compared with those IL-1ß groups without EVs, whereas the gene expression levels of COLX, IL1B, MMP13, and ALPL were significantly decreased in IL-1ß+ EV groups compared to IL-1ß groups without EVs. In addition, the phosphorylation status of Erk1/2, PI3K/Akt, p38, TAK1, and NF-κB signaling molecules, induced by IL-1ß, is prevented by hBMSC- EVs. Conclusion: EVs derived from hBMSCs alleviated IL-1ß-induced catabolic effects on OA-CH via promoting proliferation and migration and reducing apoptosis, probably via downregulation of IL-1ß-activated pro-inflammatory Erk1/2, PI3K/Akt, p38, TAK1, and NF-κB signaling pathways. EVs released from BMSCs may be considered as promising cell-free intervention strategy in cartilage regenerative medicine, avoiding several adverse effects of cell-based regenerative approaches.

Influence of Extracellular Vesicles Isolated From Osteoblasts of Patients With Cox-Arthrosis and/or Osteoporosis on Metabolism and Osteogenic Differentiation of BMSCs.

Background: Studies with extracellular vesicles (EVs), including exosomes, isolated from mesenchymal stem cells (MSC) indicate benefits for the treatment of musculoskeletal pathologies as osteoarthritis (OA) and osteoporosis (OP). However, little is known about intercellular effects of EVs derived from pathologically altered cells that might influence the outcome by counteracting effects from "healthy" MSC derived EVs. We hypothesize, that EVs isolated from osteoblasts of patients with hip OA (coxarthrosis/CA), osteoporosis (OP), or a combination of both (CA/OP) might negatively affect metabolism and osteogenic differentiation of bone-marrow derived (B)MSCs. Methods: Osteoblasts, isolated from bone explants of CA, OP, and CA/OP patients, were compared regarding growth, viability, and osteogenic differentiation capacity. Structural features of bone explants were analyzed via µCT. EVs were isolated from supernatant of naïve BMSCs and CA, OP, and CA/OP osteoblasts (osteogenic culture for 35 days). BMSC cultures were stimulated with EVs and subsequently, cell metabolism, osteogenic marker gene expression, and osteogenic differentiation were analyzed. Results: Trabecular bone structure was different between the three groups with lowest number and highest separation in the CA/OP group. Viability and Alizarin red staining increased over culture time in CA/OP osteoblasts whereas growth of osteoblasts was comparable. Alizarin red staining was by trend higher in CA compared to OP osteoblasts after 35 days and ALP activity was higher after 28 and 35 days. Stimulation of BMSC cultures with CA, OP, and CA/OP EVs did not affect proliferation but increased caspase 3/7-activity compared to unstimulated BMSCs. BMSC viability was reduced after stimulation with CA and CA/OP EVs compared to unstimulated BMSCs or stimulation with OP EVs. ALP gene expression and activity were reduced in BMSCs after stimulation with CA, OP, and CA/OP EVs. Stimulation of BMSCs with CA EVs reduced Alizarin Red staining by trend. Conclusion: Stimulation of BMSCs with EVs isolated from CA, OP, and CA/OP osteoblasts had mostly catabolic effects on cell metabolism and osteogenic differentiation irrespective of donor pathology and reflect the impact of tissue microenvironment on cell metabolism. These catabolic effects are important for understanding differences in effects of EVs on target tissues/cells when harnessing them as therapeutic drugs.

Extracellular Citrate Fuels Cancer Cell Metabolism and Growth.

Cancer cells need excess energy and essential nutrients/metabolites not only to divide and proliferate but also to migrate and invade distant organs for metastasis. Fatty acid and cholesterol synthesis, considered a hallmark of cancer for anabolism and membrane biogenesis, requires citrate. We review here potential pathways in which citrate is synthesized and/or supplied to cancer cells and the impact of extracellular citrate on cancer cell metabolism and growth. Cancer cells employ different mechanisms to support mitochondrial activity and citrate synthesis when some of the necessary substrates are missing in the extracellular space. We also discuss the different transport mechanisms available for the entry of extracellular citrate into cancer cells and how citrate as a master metabolite enhances ATP production and fuels anabolic pathways. The available literature suggests that cancer cells show an increased metabolic flexibility with which they tackle changing environmental conditions, a phenomenon crucial for cancer cell proliferation and metastasis.

EDX-analysis of fluoride precipitation on human enamel.

One mechanism of action for the anticaries effect of topical fluoridation is through precipitation of CaF2. In this in vitro study energy-dispersive x-ray spectroscopy (EDX) is used as a semiquantitative method to detect enamel fluoride-precipitation under the influence of acidic and neutral pH-value and absence or presence of a salivary pellicle. Crowns of 30 human caries-free third molars were quartered into four specimens and the enamel surface ground flat and polished. Two specimens each were stored in human saliva (120 minutes pellicle formation). Teeth were randomly allocated into 6 treatment groups: NaF_a (experimental acidic sodium fluoride; 12500 ppmF-, pH 4.75); NaF_n (experimental neutral sodium fluoride; 12500 ppmF-, pH 7.0); GB_a (acidic gel base; 0 ppmF-, pH 4.75); GB_n (neutral gel base; 0 ppmF-, pH 7.0); AmF-NaF_a (experimental acidic amine/sodium fluoride; 12500 ppmF-, pH 4.75); EG_a (acidic amine/sodium fluoride; Elmex Geleé, CP-GABA GmbH; 12500 ppmF-, pH 4.75). Each gel was applied for 60 seconds to one specimen with and one specimen without pellicle. Two specimens served as controls (no gel, without/with pellicle). Atomic percent (At%) of O, F, Na, Mg, P, Ca was measured by EDX. ∆At% and Ca/P-ratios were calculated. EDX could semi-quantify superficial enamel fluoride-precipitation. Only specimens treated with acidic fluoride gels showed fluoride-precipitation, a salivary pellicle tended to decrease At%F.

Flowable composites for restoration of non-carious cervical lesions: Results after five years.

OBJECTIVES: To evaluate the clinical performance of two flowable composites for restoration of Class-V non-carious cervical lesions (NCCLs), one with novel (N'Durance® Dimer Flow, Septodont; ND) and one with modified conventional matrix composition (Filtek™ Supreme XTE Flow, 3M-ESPE; FS). The null hypothesis was that both flowable composite materials perform equally regarding clinical quality and survival. METHODS: 50 patients received one ND and one FS restoration of NCCLs in premolars using Clearfil Protect Bond (Kuraray) as an adhesive without additional selective enamel etching. Restorations were evaluated at baseline (BL), after 30 and 60 months employing selected original FDI criteria and refined FDI criteria by separate evaluation of enamel and dentine margins. Non-parametric statistical analyses and χ2 tests were applied (α=0.05). RESULTS: 38 patients with both restorations under risk were available for the 60-mo recall (recall rate: 76%). At 60-mo, 94.7% of ND and 84.2% of FS restorations were rated clinically acceptable. No significant differences for all selected FDI criteria were recorded between ND and FS at each examination time point except for the criteria surface lustre at 60-mo, where FS showed significantly better results. No significant differences over time could be detected for both materials. There was a trend for more deterioration along the enamel margins than along the dentine margins (criteria marginal staining and marginal adaptation). SIGNIFICANCE: Within the limitations of the study, the null hypothesis that materials perform equally could not be rejected. Both flowable composites performed similarly regarding clinical performance.

Flowable composites for restoration of non-carious cervical lesions: Three-year results.

OBJECTIVES: To evaluate the clinical performance of two flowable composites for restoring Class-V non-carious cervical lesions (NCCLs), one with novel (ND; N'Durance® Dimer Flow, Septodont) and one with modified conventional matrix composition (FS; Filtek™ Supreme XTE Flow, 3M-ESPE). The null hypothesis was that both flowable composites perform equally regarding clinical quality and survival. METHODS: 50 patients received one ND and one FS restoration of NCCLs in premolars using Clearfil Protect Bond (Kuraray) as an adhesive. Restorations were evaluated by two examiners at baseline (BL), 18 and 36 months employing FDI criteria. Non-parametric statistical analyses and χ2 tests were applied (α=0.05). RESULTS: 48 patients with both restorations under risk participated in the 36-mo recall. One patient terminated participation after the 18-mo recall. One ND restoration failed at the 18-mo recall (fracture). One FS restoration failed during clinical examination at the 36-mo recall (debonding). 95.8% of restorations each were rated clinically acceptable at 36-mo. No significant differences for all selected FDI criteria were recorded between ND and FS at each examination time point except for the criteria surface staining at 36-mo and marginal staining at 18-mo and 36-mo, where FS showed significantly better results. For each material, no significant differences over time were detected, except for loss of surface lustre for FS (BL to 18 months). SIGNIFICANCE: Within the limitations of the study, the null hypothesis that materials perform equally could not be rejected. Both flowable composites performed equally regarding survival and similarly regarding clinical performance.

Controlled, prospective, randomized, clinical split-mouth evaluation of partial ceramic crowns luted with a new, universal adhesive system/resin cement: results after 18 months.

OBJECTIVES: A new universal adhesive with corresponding luting composite was recently marketed which can be used both, in a self-etch or in an etch-and-rinse mode. In this study, the clinical performance of partial ceramic crowns (PCCs) inserted with this adhesive and the corresponding luting material used in a self-etch or selective etch approach was compared with a self-adhesive universal luting material. MATERIAL AND METHODS: Three PCCs were placed in a split-mouth design in 50 patients. Two PCCs were luted with a combination of a universal adhesive/resin cement (Scotchbond Universal/RelyX Ultimate, 3M ESPE) with (SB+E)/without (SB-E) selective enamel etching. Another PCC was luted with a self-adhesive resin cement (RelyX Unicem 2, 3M ESPE). Forty-eight patients were evaluated clinically according to FDI criteria at baseline and 6, 12 and 18 months. For statistical analyses, the chi-square test (α = 0.05) and Kaplan-Meier analysis were applied. RESULTS: Clinically, no statistically significant differences between groups were detected over time. Within groups, clinically significant increase for criterion "marginal staining" was detected for SB-E over 18 months. Kaplan-Meier analysis revealed significantly higher retention rates for SB+E (97.8 %) and SB-E (95.6 %) in comparison to RXU2 (75.6 %). CONCLUSION: The 18-month clinical performance of a new universal adhesive/composite combination showed no differences with respect to bonding strategy and may be recommended for luting PCCs. Longer-term evaluation is needed to confirm superiority of SB+E over SB-E. CLINICAL RELEVANCE: At 18 months, the new multi-mode adhesive, Scotchbond Universal, showed clinically reliable results when used for luting PCCs.

Self-adhesive Luting of Partial Ceramic Crowns: Selective Enamel Etching Leads to Higher Survival after 6.5 Years In Vivo.

PURPOSE: To investigate the influence of selective enamel etching on long-term clinical performance of partial ceramic crowns (PCCs) luted with a self-adhesive luting material (RXU: RelyX Unicem). MATERIALS AND METHODS: At baseline, 34 patients received the intended treatment: two PCCs (Vita Mark II; Cerec 3D) for the restoration of extended lesions with multiple-cusp coverage were placed in a split-mouth design with a self-adhesive luting material, one without (RXU) and one with selective enamel etching (RXU+E). Patients were evaluated clinically (modified USPHS criteria) at baseline and up to 6.5 years (70 to 88 months). The chi-square test was used for statistical analyses (α=0.05). Clinical survival of all restorations (n=68) after 6.5 years was evaluated by Kaplan-Meier analysis. RESULTS: After 6.5 years, 18 patients (9 male, 9 female; median age 41, range 25 to 59 years) with 36 RXU and RXU+E restorations were available for clinical assessment (patient recall rate: 53%), with 13 RXU and 14 RXU+E PCCs placed in molars and 5 RXU and 4 RXU+E PCCs in premolars. Clinically, no statistically significant differences between the luting procedures were detected. Both RXU and RXU+E revealed significant changes over time with respect to marginal adaptation (significant deterioration) and marginal discoloration (significant increase). RXU revealed no cases of postoperative hypersensitivity and RXU+E only did so at baseline (n=5). Kaplan-Meier analysis showed a cumulative survival for RXU of 60% and for RXU+E of 82%, indicating a significantly higher survival rate for RXU+E. CONCLUSION: Clinically, RXU and RXU+E perform similarly. In PCC restorations with multiple-cusp coverage, lack of retention due to adhesive preparation, and little dentin available for adhesion caused by extensive core buildups or cavity linings, selective enamel etching is recommended.

Influence of root canal disinfectants on growth factor release from dentin.

INTRODUCTION: During dentinogenesis, growth factors become entrapped in the dentin matrix that can later be released by demineralization. Their effect on pulpal stem cell migration, proliferation, and differentiation could be beneficial for regenerative endodontic therapies. However, precondition for success, as for conventional root canal treatment, will be sufficient disinfection of the root canal system. Various irrigation solutions and intracanal dressings are available for clinical use. The aim of this study was 2-fold: to identify a demineralizing solution suitable for growth factor release directly from dentin and to evaluate whether commonly used disinfectants for endodontic treatment will compromise this effect. METHODS: Dentin disks were prepared from extracted human teeth and treated with EDTA or citric acid at different concentrations or pH for different exposure periods. The amount of transforming growth factor-ß1 (TGF-ß1), fibroblast growth factor 2, and vascular endothelial growth factor were quantified via enzyme-linked immunosorbent assay and visualized by gold labeling. Subsequently, different irrigation solutions (5.25% sodium hypochloride, 0.12% chlorhexidine digluconate) and intracanal dressings (corticoid-antibiotic paste, calcium hydroxide: water-based and oil-based, triple antibiotic paste, chlorhexidine gel) were tested, and the release of TGF-ß1 was measured after a subsequent conditioning step with EDTA. RESULTS: Conditioning with 10% EDTA at pH 7 rendered the highest amounts of TGF-ß1 among all test solutions. Fibroblast growth factor 2 and vascular endothelial growth factor were detected after EDTA conditioning at minute concentrations. Irrigation with chlorhexidine before EDTA conditioning increased TGF-ß1 release; sodium hypochloride had the opposite effect. All tested intracanal dressings interfered with TGF-ß1 release except water-based calcium hydroxide. CONCLUSIONS: Growth factors can be released directly from dentin via EDTA conditioning. The use of disinfecting solutions or medicaments can amplify or attenuate this effect.

In-depth characterisation of Retinal Pigment Epithelium (RPE) cells derived from human induced pluripotent stem cells (hiPSC).

Induced pluripotent stem cell (iPSC)-derived retinal pigment epithelium (RPE) has widely been appreciated as a promising tool to model human ocular disease emanating from primary RPE pathology. Here, we describe the successful reprogramming of adult human dermal fibroblasts to iPSCs and their differentiation to pure expandable RPE cells with structural and functional features characteristic for native RPE. Fibroblast cultures were established from skin biopsy material and subsequently reprogrammed following polycistronic lentiviral transduction with OCT4, SOX2, KLF4 and L-Myc. Fibroblast-derived iPSCs showed typical morphology, chromosomal integrity and a distinctive stem cell marker profile. Subsequent differentiation resulted in expandable pigmented hexagonal RPE cells. The cells revealed stable RNA expression of mature RPE markers RPE65, RLBP and BEST1. Immunolabelling verified localisation of BEST1 at the basolateral plasma membrane, and scanning electron microscopy showed typical microvilli at the apical side of iPSC-derived RPE cells. Transepithelial resistance was maintained at high levels during cell culture indicating functional formation of tight junctions. Secretion capacity was demonstrated for VEGF-A. Feeding of porcine photoreceptor outer segments revealed the proper ability of these cells for phagocytosis. IPSC-derived RPE cells largely maintained these properties after cryopreservation. Together, our study underlines that adult dermal fibroblasts can serve as a valuable resource for iPSC-derived RPE with characteristics highly reminiscent of true RPE cells. This will allow its broad application to establish cellular models for RPE-related human diseases.

Effect of selective enamel etching on clinical performance of CAD/CAM partial ceramic crowns luted with a self-adhesive resin cement.

OBJECTIVES: This study was conducted to evaluate a self-adhesive resin luting cement [RelyX Unicem 3MESPE-RXU] for luting partial ceramic crowns (PCCs) with and without selective enamel etching in a prospective, randomized clinical trial. MATERIALS AND METHODS: Thirty-four patients had received the intended treatment. Two PCCs (Vita Mark II; Cerec 3D; Sirona) had been placed in a split-mouth design: one with RXU without enamel etching (RXU), the other with RXU with selective enamel etching (RXU + E). Restorations were evaluated at baseline (BL) and after 12, 24, and 36 months (USPHS criteria). For statistical analysis, the Chi-square test was applied (α = 0.05). Clinical survival of all restorations (n = 68) after 3 years was determined using Kaplan-Meier analysis. RESULTS: Twenty three patients (12 male/11 female) were available for clinical evaluation after 3 years. 19 RXU-PCCs were placed in molars, four in premolars, 18 RXU + E-PCCs in molars, five in premolars. Concerning clinical changes, no significant differences were found between luting strategies RXU/RXU + E at all recalls. Statistically significant changes over time were observed for marginal adaptation and marginal discoloration between BL and 36 m for RXU and RXU + E. For RXU + E, postoperative hypersensitivities decreased significantly from BL (n = 6) to 36 m (n = 0). Of the 68 restorations originally included, eight RXU and four RXU + E restorations failed. At 3 years, Kaplan-Meier survival of RXU was 72.9 %, that of RXU + E 87.6 %. Survival rates were not statistically significant different. CONCLUSIONS: Although clinical survival of RXU + E is slightly better at 3 years, restorations of both groups perform similar with respect to clinical changes over time as evaluated by modified USPHS criteria. CLINICAL RELEVANCE: The self-adhesive resin cement RXU can be used in conjunction with selective enamel etching, because survival rates of PCCs in the RXU + E group were not lower but, as a trend, even better than without enamel etching.