ATP6AP2 is robustly expressed in pancreatic ß cells and neuroendocrine tumors, and plays a role in maintaining cellular viability.

ATP6AP2, also known as (pro)renin receptor, has been shown to be expressed in several tissues including pancreatic ß cells. Whereas ATP6AP2 plays an important role in regulating insulin secretion in mouse pancreatic ß cells, the expression profiles and roles of ATP6AP2 in human pancreatic endocrine cells and neuroendocrine tumor cells remain unclear. Here in this study, we investigated the expression profiles of ATP6AP2 in pancreatic endocrine cells, and found that ATP6AP2 is robustly expressed in pancreatic insulinoma cells as well as in normal ß cells. Although ATP6AP2 was also expressed in low-grade neuroendocrine tumors, it was not or faintly detected in intermediate- and high-grade neuroendocrine tumors. Knockdown experiments of the Atp6ap2 gene in rat insulinoma-derived INS-1 cells demonstrated decreased cell viability accompanied by a significant increase in apoptotic cells. Taken together, these findings suggest that ATP6AP2 plays a role in maintaining cellular homeostasis in insulinoma cells, which could lead to possible therapeutic approaches for endocrine tumors.

Oncolytic vaccinia virus injected intravenously sensitizes pancreatic neuroendocrine tumors and metastases to immune checkpoint blockade.

This study determined the influence of intravenous (i.v.) oncolytic vaccinia virus mpJX-594 (mpJX) on antitumor activity of anti-programmed death receptor-1 antibody (aPD1) in functional and metastatic pancreatic neuroendocrine tumors (PanNETs). One i.v. dose of mpJX, engineered for mice with the same plasmid design as clinical virus Pexa-Vec, was administered alone or with repeated dosing of aPD1 (mpJX+aPD1) to two contrasting genetic models of PanNET: one developing benign insulin-secreting tumors (RIP1-Tag2;C57BL/6J mice) and the other developing liver metastases (RIP1-Tag2;AB6F1 mice). Experiments revealed that aPD1 had synergistic actions with mpJX on CD8+ T cell and natural killer (NK) cell influx, apoptosis, and suppression of proliferation in PanNETs. After mpJX+aPD1, the 53-fold increase in apoptosis (5 days) and 85% reduction in proliferation (20 days) exceeded the sum of mpJX and aPD1 given separately. mpJX+aPD1 also stabilized blood insulin and glucose in mice with functional PanNETs, regressed liver metastases in mice with aggressive PanNETs, and prolonged survival of both. The findings revealed that mpJX+aPD1 converted "cold" PanNETs into immunogenic tumors with widespread cytotoxic T cell influx, tumor cell killing, and suppression of proliferation. Reduction of tumor insulin secretion from functional PanNETs prolonged survival, and anti-metastatic actions on aggressive PanNETs reduced the metastatic burden to less than before treatment. The findings support the efficacy of the vaccinia virus with aPD1 for functional and metastatic PanNETs.

Oncolytic Vaccinia Virus Gene Modification and Cytokine Expression Effects on Tumor Infection, Immune Response, and Killing.

Oncolytic vaccinia viruses have promising efficacy and safety profiles in cancer therapy. Although antitumor activity can be increased by manipulating viral genes, the relative efficacy of individual modifications has been difficult to assess without side-by-side comparisons. This study sought to compare the initial antitumor activity after intravenous administration of five vaccinia virus variants of the same Western Reserve backbone and thymidine kinase gene deletion in RIP-Tag2 transgenic mice with spontaneous pancreatic neuroendocrine tumors. Tumors had focal regions of infection at 5 days after all viruses. Natural killer (NK) cells were restricted to these sites of infection, but CD8+ T cells and tumor cell apoptosis were widespread and varied among the viruses. Antitumor activity of virus VV-A34, bearing amino acid substitution A34K151E to increase viral spreading, and virus VV-IL2v, expressing a mouse IL2 variant (mIL2v) with attenuated IL2 receptor alpha subunit binding, was similar to control virus VV-GFP. However, antitumor activity was significantly greater after virus VV-A34/IL2v, which expressed mIL2v together with A34K151E mutation and viral B18R gene deletion, and virus VV-GMCSF that expressed mouse GM-CSF. Both viruses greatly increased expression of CD8 antigens Cd8a/Cd8b1 and cytotoxicity genes granzyme A, granzyme B, Fas ligand, and perforin-1 in tumors. VV-A34/IL2v led to higher serum IL2 and greater tumor expression of death receptor ligand TRAIL, but VV-GMCSF led to higher serum GM-CSF, greater expression of leukocyte chemokines and adhesion molecules, and more neutrophil recruitment. Together, the results show that antitumor activity is similarly increased by viral expression of GM-CSF or IL2v combined with additional genetic modifications.

A Case of Suspicious Allergic Reaction to Peracetic Acid Following Endoscopy.

A 43-year-old man with rheumatic arthritis was admitted to our hospital for symptoms of cough, left chest pain, and left elbow pain, and further examination revealed an elevated level of C-reactive protein. On day 2 after admission, he underwent esophagogastroduodenoscopy. On the morning of day 7, he developed a high fever of 39.7°C, several hours after bronchoscopy. On day 13, he underwent colonoscopy. Five minutes after the colonoscopy, he developed a high fever of 39.9°C, accompanied by stridor, indicating a decrease in arterial oxygen saturation level. An intradermal test for peracetic acid which was used for cleaning flexible endoscopy was positive. We suspect that he suffered from an allergic reaction to peracetic acid following the flexible endoscopy. This is the first case reported on suspicious allergic reaction to peracetic acid following a flexible endoscopy procedure.

Biological Effects of Anti-RANKL Antibody and Zoledronic Acid on Growth and Tooth Eruption in Growing Mice.

The anti-bone resorptive drugs denosumab, an anti-human-RANKL antibody, and zoledronic acid (ZOL), a nitrogen-containing bisphosphonate, have recently been applied for treatment of pediatric patients with bone diseases, though details regarding their effects in growing children have yet to be fully elucidated. In the present study, we administered these anti-resorptive drugs to mice from the age of 1 week and continued once-weekly injections for a total of 7 times. Mice that received the anti-RANKL antibody displayed normal growth and tooth eruption, though osteopetrotic bone volume gain in long and alveolar bones was noted, while there were nearly no osteoclasts and a normal of number osteoblasts observed. In contrast, ZOL significantly delayed body growth, tooth root formation, and tooth eruption, with increased osteoclast and decreased osteoblast numbers. These findings suggest regulation of tooth eruption via osteoblast differentiation by some types of anti-resorptive drugs.

Effects of canagliflozin on body composition and hepatic fat content in type 2 diabetes patients with non-alcoholic fatty liver disease.

AIMS/INTRODUCTION: Non-alcoholic fatty liver disease is frequently associated with type 2 diabetes, and constitutes an important risk factor for the development of hepatic fibrosis and hepatocellular carcinoma. Because there remains no effective drug therapy for non-alcoholic fatty liver disease associated with type 2 diabetes, we evaluated the efficacy of sodium-glucose cotransporter 2 inhibitor. METHODS AND MATERIALS: In the present pilot, prospective, non-randomized, open-label, single-arm study, we evaluated the effect of 100 mg canagliflozin administered once daily for 12 months on serological markers, body composition measured by bioelectrical impedance analysis method and hepatic fat fraction measured by magnetic resonance imaging in type 2 diabetes patients with non-alcoholic fatty liver disease. RESULTS: Canagliflozin significantly reduced body and fat mass, and induced a slight decrease in lean body or muscle mass that did not reach significance at 6 and 12 months. Reductions in fat mass in each body segment (trunk, arms and legs) were evident, whereas those in lean body mass were not. The hepatic fat fraction was reduced from a baseline of 17.6 ± 7.5% to 12.0 ± 4.6% after 6 months and 12.1 ± 6.1% after 12 months (P < 0.0005 and P < 0.005), whereas serum liver enzymes and type IV collagen concentrations improved. From a mean baseline hemoglobin A1c of 8.7 ± 1.4%, canagliflozin significantly reduced hemoglobin A1c after 6 and 12 months to 7.3 ± 0.6% and 7.7 ± 0.7% (P < 0.0005 and P < 0.01). CONCLUSIONS: Canagliflozin reduced body mass, fat mass and hepatic fat content without significantly reducing muscle mass.

Quantitative proteomic analysis of gingival crevicular fluids from deciduous and permanent teeth.

AIM: Gingivitis commonly progresses to periodontitis in permanent dentition but rarely in deciduous teeth. Little is known about the biochemical differences between gingiva of deciduous and permanent teeth. Here, we compared the protein profiles of gingival crevicular fluids (GCF) from the gingiva of deciduous and permanent teeth. MATERIALS AND METHODS: Forty children with mixed dentition (Hellman's dental age IIIA) were selected and GCF samples were collected from deciduous cuspids and central incisors in the maxilla. Pairs of GCF samples were labelled using isobaric tags to permit quantitative comparison of protein abundance in the samples using liquid chromatography-electron spray ionization-tandem mass spectrometry. RESULTS: Sixty-two proteins were upregulated in deciduous teeth GCF and 54 in permanent teeth GCF. In particular, neutrophil-derived proteins, including myeloperoxidase and lactoferrin, were repeatedly higher in deciduous teeth GCF than in permanent teeth GCF. These differences were verified using ELISA (p < 0.01). In contrast, immunoglobulin components were upregulated in permanent teeth GCF. CONCLUSIONS: Neutrophil-related proteins were enriched in deciduous teeth GCF and immunoglobulins in permanent teeth GCF. This suggests that neutrophil accumulation plays a protective role in innate immunity against bacterial infection in gingival tissue of deciduous teeth.

[Anesthetic Management with Propofol Alone in a Patient with Hereditary Sensory and Autonomic Neuropathy].

Hereditary sensory and autonomic neuropathy (HSAN) is a rare peripheral nerve disorder associated with sensory dysfunction (pain, touch, and pressure) and various degrees of autonomic dysfunction. We administered general anesthesia for a 54-year-old woman with HSAN type II undergoing amputation of the left hallux. She had reduced sensation for pain, pressure, and temperature since birth and frequently injured her hands and legs. Before the operation, she did not report pain in the hallux. Only propofol was given for anesthesia without use of analgesia. Intraoperatively, her vital signs were stable. To evaluate the sympathetic nervous response to surgical stimulation, we measured the plasma catecholamine levels before tracheal intubation and just before and during surgery. Plasma catecholamine levels were normal at all time points, indicating no sympathetic responses to surgical stimulation. This case suggests that anesthesia for HSAN II patients can be safely managed with propofol alone.

[A Case of General Anesthesia for a Cardiac Transplanted Patient Undergoing Inguinal Hernia Repair under Laparoscopic Surgery].

A 52-year-old man was scheduled for the repair of inguinal hernia recurrence. When he was 48 years of age, he received a heart transplantation due to severe heart failure resulting from ischemic heart disease. When he was 50 years old, he suffered from inguinal hernia, and it was repaired under spinal anesthesia. During this surgery, he experienced pain because of the inadequate effect of anesthesia, but his blood pressure and heart rate were stable. We suspected that this was because of denervation of the heart. On hernia repair for inguinal hernia recurrence, general anesthesia was chosen, induced with midazolam, rocuronium, and fentanyl and maintained with sevoflurane, rocuronium, fentanyl, and remifentanil. The blood pressure was mostly stable during anesthesia, but we noted an increase in the heart rate when the trachea was intubated and extubated and when surgical incision started. This phenomenon may indicate reinnervation of the transplanted heart. We could safely manage anesthesia without invasive monitoring because the transplanted heart functioned favorably and surgery was minimally invasive.

Involvement of histaminergic inputs in the jaw-closing reflex arc.

Histamine receptors are densely expressed in the mesencephalic trigeminal nucleus (MesV) and trigeminal motor nucleus. However, little is known about the functional roles of neuronal histamine in controlling oral-motor activity. Thus, using the whole-cell recording technique in brainstem slice preparations from Wistar rats aged between postnatal days 7 and 13, we investigated the effects of histamine on the MesV neurons innervating the masseter muscle spindles and masseter motoneurons (MMNs) that form a reflex arc for the jaw-closing reflex. Bath application of histamine (100 µM) induced membrane depolarization in both MesV neurons and MMNs in the presence of tetrodotoxin, whereas histamine decreased and increased the input resistance in MesV neurons and MMNs, respectively. The effects of histamine on MesV neurons and MMNs were mimicked by an H1 receptor agonist, 2-pyridylethylamine (100 µM). The effects of an H2 receptor agonist, dimaprit (100 µM), on MesV neurons were inconsistent, whereas MMNs were depolarized without changes in the input resistance. An H3 receptor agonist, immethridine (100 µM), also depolarized both MesV neurons and MMNs without changing the input resistance. Histamine reduced the peak amplitude of postsynaptic currents (PSCs) in MMNs evoked by stimulation of the trigeminal motor nerve (5N), which was mimicked by 2-pyridylethylamine but not by dimaprit or immethridine. Moreover, 2-pyridylethylamine increased the failure rate of PSCs evoked by minimal stimulation and the paired-pulse ratio. These results suggest that histaminergic inputs to MesV neurons through H1 receptors are involved in the suppression of the jaw-closing reflex although histamine depolarizes MesV neurons and/or MMNs.

Regulation of Osteoclast Multinucleation by the Actin Cytoskeleton Signaling Network.

Although it is known that osteoclasts are multinucleated cells that are responsible for bone resorption, the mechanism by which their size is regulated is unclear. We previously reported that an actin-rich superstructure, termed the zipper-like structure, specifically appears during the fusion of large osteoclast-like cells (OCLs). Actin cytoskeleton reorganization in osteoclasts is regulated by a signaling network that includes the macrophage colony-stimulating factor (M-CSF) receptor, a proto-oncogene, Src, and small GTPases. Here, we examined the role of actin reorganization in the multinucleation of OCLs differentiated from RAW 264.7 cells using various pharmacological agents. Jasplakinolide, which stabilizes actin stress fibers, induced the development of small OCLs, and the Src inhibitor SU6656 and the dynamin inhibitor dynasore impaired the maintenance of the podosome belt and the zipper-like structure. These inhibitors decreased the formation of large OCLs but increased the number of small OCLs. M-CSF is known to stimulate osteoclast fusion. M-CSF signaling via Src up-regulated Rac1 activity but down-regulated Rho activity. Rac1 and Rho localized to the center of the zipper-like structure. Rho activator II promoted the formation of small OCLs, whereas the Rho inhibitor Y27632 promoted the generation of large OCLs. These results suggest that the status of the actin cytoskeleton signaling network determines the size of OCLs during cell fusion.

Nanoindentation tests to assess polymerization of resin-based luting cement.

OBJECTIVE: The optimal polymerization of resin-based luting cements plays a critical role in the long-term clinical success of dental prostheses and indirect restorations. This study investigated a mutual action between the conformational changes and mechanical properties of a dimethacrylate resin-based luting cement with and without pre-application of the acidic functional monomer 10-methacryloxydecyl dihydrogen phosphate. METHODS: Degree of conversion in the luting cement was measured using conventional infrared spectrophotometry. Mechanical properties of the luting cements were also evaluated by quasi-static and dynamic nanoindentation tests. RESULTS: The results of infrared spectrophotometry and nanoindentation testing were proportional in samples without functional monomer pretreatment. When considerable residual monomer remains within the final products, the mechanical properties of the resin-based luting cements could possibly be impaired. Although the apparent degree of conversion increased with a mixture of functional monomer, a reduction in the cross-linking polymer network may have resulted in the highest viscoelastic creep behavior of the luting cement. The time-dependent behaviors found in the nanoindentation tests likely resulted from linear polymerization chains of the functional monomer. SIGNIFICANCE: The application of an acidic functional monomer may affect the viscosity of resin-based luting cements. Quasi-static or dynamic nanoindentation is a useful tool for assessing the polymerization qualities of resin composites.

Identification and functional analysis of the gene cluster for fructan utilization in Prevotella intermedia.

Fructanase enzymes hydrolyze the ß-2,6 and ß-2,1 linkages of levan and inulin fructans, respectively. We analyzed the influence of fructan on the growth of Prevotella intermedia. The growth of P. intermedia was enhanced by addition of inulin, implying that P. intermedia could also use inulin. Based on this finding, we identified and analyzed the genes encoding a putative fructanase (FruA), sugar transporter (FruB), and fructokinase (FruK) in the genome of strain ATCC25611. Transcript analysis by RT-PCR showed that the fruABK genes were co-transcribed as a single mRNA and semi-quantitative analysis confirmed that the fruA gene was induced in response to fructose and inulin. Recombinant FruA and FruK were purified and characterized biochemically. FruA strongly hydrolyzed inulin, with slight degradation of levan via an exo-type mechanism, revealing that FruA is an exo-ß-d-fructanase. FruK converted fructose to fructose-6-phosphate in the presence of ATP, confirming that FruK is an ATP-dependent fructokinase. These results suggest that P. intermedia can utilize fructan as a carbon source for growth, and that the fructanase, sugar transporter, and fructokinase proteins we identified are involved in this fructan utilization.

An experimental study on mineral triozide aggregate and calcium hydroxide-based paste applied to direct pulp capping in rat / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the volume change of rat root following direct pulp capping with mineral triozide aggregate(MTA) and calcium hydroxide-based paste (Vitapex) .</p><p><b>METHODS</b>Sixty-four female, 1-month-old Wistar rats were randomly divided into 4 groups, MTA group, Vitapex group, model group and control group, 16 rats in each group. The right maxillary first molar was taken as experimental tooth and control tooth. The exposed pulp was capped separately with MTA and calcium hydroxide after the pulp had been exposed mechanically, while nothing done to the control group. Using micro-CT and three-dimensional reconstruction techniques, the volume change of rat root was evaluated at 1, 2, 4 weeks and 6 weeks after direct pulp capping. The data were analyzed by an way ANOVA analysis followed by a LSD-t test.</p><p><b>RESULTS</b>The root volume in the MTA group[(1.08 ± 0.07), (1.32 ± 0.18) mm(3)] was significantly smaller than that in the Vitapex group[(1.28 ± 0.16), (1.59 ± 0.18) mm(3)] at 2 and 4 weeks after operation (P < 0.05) . At the sixth week , there was no significant difference between the MTA group [(1.36 ± 0.03) mm(3)] and the Vitapex group[(1.61 ± 0.31) mm(3)] (P > 0.05) . The root volume in the MTA group and Vitapex group was significantly larger than that in the model group [(0.87 ± 0.09), (1.01 ± 0.17) , (1.02 ± 0.25) mm(3)] from the second to sixth week after operation (P < 0.05) .</p><p><b>CONCLUSIONS</b>MTA and Vitapex can effectively promote root formation and growth and can be used as biological pulp-capping material.</p>

Effects of tetracycline hydrochloride on measurements with the laser fluorescence device DIAGNOdent: in vitro and in vivo studies.

Dental materials that fluoresce affect the reading of the laser fluorescence device DIAGNOdent. Tetracycline hydrochloride (TCH) shows fluorescence and is retained in teeth. The aim of this study was to evaluate the effects of TCH on the DIAGNOdent reading. Filter-paper discs that contained various amounts of TCH were prepared (0.16-10 mg per disc). One-day-old newborn rats were subcutaneously injected with TCH for 29 days, and their mandibles were then removed. The DIAGNOdent values (D-V) of the discs and first molars of the rats were measured before and after they were subjected to ultraviolet irradiation (UV). The D-V of discs containing TCH increased depending on the amount of TCH. The D-Vs of discs with lower amounts of TCH (0.16-1.25 mg) were approximately 10-15, and these values increased to 30-40 under UV. In addition, the D-Vs of molars after UV were twofold greater than those before UV. These results suggest that TCH might affect the readings obtained by DIAGNOdent.

[Development of oral function and eating habits of infants living in a city area of Japan: in relation to the results of dental health examinations of infants aged 14 months at public health centers].

OBJECTIVE: The aim of this study was to investigate the relationships between eruption of deciduous teeth and eating habits determined by health examinations of infants. METHODS: We verified eruption of deciduous teeth based on observations of 455 fourteen-month-old infants at health examinations in a ward of Tokyo, and performed a questionnaire survey involving their mothers regarding the hardness of infants' meals and their eating habits. We examined 420 infants excluding 17 whose births were 'pre-term delivery (born at or before 36 weeks)' and 18 whose questionnaire had excessive omissions. RESULTS: The percentage of infants who began a weaning diet at 5 to 6 months of age was 81.4%, and 71.2% of mothers considered their infant's age in months before starting a weaning diet. We divided the children into three stages: those not showing full eruption of the eight front deciduous teeth (stage I, 27.4%); those with full eruptions of the eight front deciduous teeth excluding the first primary molars (stage II, 61.9%); those with full eruptions of the first primary molars (stage III, 10.7%). Most mothers cooked meals considering the hardness of the gingival gums (stage I; 53.5%, stage II; 54.4%, stage III; 40.0%). The percentage of mothers who cooked meals considering the hardness of the primary molars was 14.0 and 15.1% in stages I and II, respectively. In addition, the percentage who cooked meals while considering the hardness in relation to adult meals was 7.0, 9.7, and 24.4% in stages I, II, and III, respectively. Moreover, the percentage considering the salt-taste in relation to adult meals was 13.2, 17.3, and 22.2% in stages I, II, and III, respectively. CONCLUSION: In the present study, we obtained valuable data showing that the timing deciduous teeth eruption varies among individuals. These results suggested that nutritional education on the appropriate quality of meals for infants based on their state of deciduous teeth eruption is necessary.

[Distribution of periodontal pathogens in dental plaque samples from 7 to 12-years-old children of Changchun Ziqiang primary school].

OBJECTIVE: To detect the presence of Porphyromonas gingivalis (Pg) and Actinobacillus actinomycetemcomitans (Aa) using polymerase chain reaction (PCR) in the oral plaque samples from children and investigate the relationship between bacteria and clinical parameters. METHODS: A total of 151 children aged 7 to 12 years were selected from Changchun Ziqiang primary school. The supragingival plaque sample was collected from the mesiobuccal and labial surfaces of the right maxillary central incisor and the right maxillary first molar. Extracted DNA from plaque samples was used for PCR analysis. Intraoral examination, probing depth (PD) and bleeding on probing (BOP) were performed and recorded. RESULTS: The detection rate for Pg was 27.6% and Aa 54.3% in supragingival plaque. The detection rates for Pg in molars were much higher than those in incisors (P < 0.01). The detection rate of Pg was positively related to BOP+ and PD. The detection rate for Pg increased gradually with aging, and the detection rate for Aa was highest in the group aged 11 to 12 and the detection rates for Pg and Aa were higher in the gingiva with BOP+ than that with BOP- (P < 0.05). The detection rates for Pg increased remarkably with BOP+ and especially when PD was greater than 4 mm. CONCLUSIONS: Detection rates of putative periodontal pathogens from healthy children of 7 to 12 years of age were high. The detection rates for Pg in molars were much higher than those in incisors,and the presence of Pg and Aa in supragingival plaque was related to periodontal parameters.

Transcripts of unknown function in multiple-signaling pathways involved in human stem cell differentiation.

Mammalian transcriptome analysis has uncovered tens of thousands of novel transcripts of unknown function (TUFs). Classical and recent examples suggest that the majority of TUFs may underlie vital intracellular functions as non-coding RNAs because of their low coding potentials. However, only a portion of TUFs have been studied to date, and the functional significance of TUFs remains mostly uncharacterized. To increase the repertoire of functional TUFs, we screened for TUFs whose expression is controlled during differentiation of pluripotent human mesenchymal stem cells (hMSCs). The resulting six TUFs, named transcripts related to hMSC differentiation (TMDs), displayed distinct transcriptional kinetics during hMSC adipogenesis and/or osteogenesis. Structural and comparative genomic characterization suggested a wide variety of biologically active structures of these TMDs, including a long nuclear non-coding RNA, a microRNA host gene and a novel small protein gene. Moreover, the transcriptional response to established pathway activators indicated that most of these TMDs were transcriptionally regulated by each of the two key pathways for hMSC differentiation: the Wnt and protein kinase A (PKA) signaling pathways. The present study suggests that not only TMDs but also other human TUFs may in general participate in vital cellular functions with different molecular mechanisms.

Mechanical properties and bond strength of silicone-based resilient denture liners.

To evaluate the ease of manipulation and durability of 11 commercially available silicone-based resilient denture liners, extrusion force, hardness, weight change, and bond strength were determined. Extrusion force from the cartridge of each material ranged from 0.25 to 1.26 MPa at an extrusion rate of 1 cm/min. Durometer hardness, after set materials were stored in distilled water at 37 degrees C for one day, ranged from A5.9 to A47.7, and after four weeks their values increased by 4.0 to 275%. Bond strength ranged from 1.01 to 2.88 MPa after set materials were stored in distilled water at 37 degrees C for one day, but decreased to 0.59 to 1.99 MPa after 10,000 thermal cycles. These results suggested that except for one material, the rest of the evaluated materials exhibited good handling properties--for example, mixing and spreading of material can be done easily. However, some materials exhibited inadequate durability for clinical service, because hardness increased during storage and/or bond strength decreased after thermal cycling.

Efficacy of a self-etching dentin primer composed of TEGMA and phenyl-P.

The purpose of the present study was to evaluate the efficacy of an experimental self-etching dentin primer composed of TEGMA and phenyl-P using primary and young permanent teeth. The efficacy of the self-etching dentin primer was evaluated by measuring the wall-to-wall polymerization contraction gap width and the shear bond strength to the flat dentin surface. The contraction gap formation was prevented completely in the specimens primed with the 35 vol% TEGMA and 20% phenyl-P for 30 sec.