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Objective This study investigated the handling and surface characteristics of universal resin composites and determined the interrelations among the composites’ handling, mechanical, and physical properties. Methods Five recently introduced universal resin composites were tested. Twelve specimens per material were used to measure the stiffness and stickiness (handling properties) of the resin composite pastes. Additionally, surface properties (Knoop hardness number [KHN], surface roughness [Sa], surface gloss [SG], water contact angle [CA], and surface free energy [SFE]) of cured resin composites were determined in 12 specimens per material immediately after preparation (baseline) and after subjection to thermal cycles (TCs). Results Handling and surface properties of the resin composites were material dependent. All the resin composites showed significantly lower KHN in the post-TC subgroups than that in the baseline subgroups. However, the influence of TC on the other surface properties was dependent on the material used. Some resin composites did not indicate any significant differences in Sa, SG, or CA between the baseline and post-TC groups. Significance Although the resin composites in the baseline groups presented with different handling and surface properties, the surface properties of most of the composites were significantly affected by TC. Extremely strong positive or negative correlations were observed between stiffness and stickiness, KHN and Sa, KHN and SG, Sa and SG, and CA and SFE. Most correlations between the handling and surface properties were weak. Therefore, the selection of resin composites in clinical situations should be based on comprehensive consideration of their properties.

Purpose This study investigated the influence of professional mechanical tooth cleaning (PMTC) pastes on the surface texture of different subject materials. Methods Two one-step PMTC pastes, Clinpro Cleaning Paste for PMTC (CP) and PRG Pro-Care Gel (PG), and multiple-step PMTC pastes, Merssage Regular (MR), Merssagge Fine (MF), and Merssage Plus (MP), were used. For comparison, PMTC was performed using distilled water without paste (DW). The subjected materials used were bovine enamel (ENA) and dentin (DEN), a resin composite (FSU), and lithium disilicate (IEC). The prepared specimens were polished using a #2000-grit silicon carbide paper. PMTC was performed using a brush at 1,000 rpm for 15 s. Results The surface roughness (Ra) values of the specimens before and after PMTC were measured by laser scanning microscopy. The Knoop hardness number (KHN) of the subjected material was obtained. The types of PMTC pastes and subject materials had a significant influence on the Ra values and KHN. For the majority of subject materials, the descending order of Ra values after PMTC was MR > MF > CP > PG > MP > DW. The descending order of KHN of the materials was IEC > ENA > FSU > DEN. Conclusion Although one-step PMTC pastes appeared to be effective, it is important to consider the subject material during PMTC.

This study investigated the effect of the bonding agent application method on the dentin bond durability of a two-step adhesive utilizing a universal-adhesive-derived primer. The bonding durability of a universal adhesive was compared with those of two conventional two-step adhesives by shear bond strength testing after thermal cycling. The primer was applied (with or without phosphoric acid pre-etching), and the specimens were divided into three groups based on the bonding agent application method used as follows: (i) strong air-flow application, (ii) gentle air-flow application, and (iii) gentle air-flow + second bonding application. The shear bond strength was determined after thermal cycling. All the factors (bonding agent application method, adhesive system, and storage condition) significantly influenced the dentin shear bond strength both with and without phosphoric acid pre-etching. The specimens exposed to gentle air-flow showed a higher shear bond strength than did those exposed to strong air-flow and gentle air-flow + second bonding. The bond durability of the tested adhesive systems was influenced by the bonding agent application method, and this trend was material dependent. The G2-Bond Universal exhibited the same or greater dentin bond durability to the other two-step adhesive systems.

This study aimed to evaluate the effect of the adhesive application method on the durability of the enamel bond and the thickness of the adhesive layer. A new-generation two-step universal adhesive system, G2-Bond Universal, and two conventional two-step adhesive systems were utilized. The shear bond strength to bovine enamel was measured after thermal cycling in both etch-and-rinse and self-etch modes. Fifteen specimens were divided into three groups as follows: Group I, wherein a strong air stream was applied over the bonding agent for 5 s, Group II, wherein a gentle air stream was applied over the bonding agent for 5 s, and Group III, which was prepared as in Group II, followed by the application of a second layer of the bonding agent and a gentle air stream for 5 s. The durability of the enamel bond and thickness of the tested adhesives were influenced by the application method in both etching modes. The application method used in Group II appeared to be most suitable in terms of the bonding of the adhesives to the enamel. The new-generation two-step self-etch adhesive, comprising a universal adhesive-derived primer and a hydrophobic bonding agent, showed superior bond performance to the conventional two-step adhesive systems.

Objective To examine the effect of filler contentTo examine the effect of filler content on structural coloration of experimental flowable resin composites. Overview Experimental composites containing spherical fillers and different filler contents (30, 40, 50, 60 and 70 wt%), a structural colored resin composite (Omnichroma), and a nanohybrid flowable resin composite (Gracefil LoFlo) were used. The optical characteristics of the specimens were measured on standard black and white backgrounds using a spectrophotometer under CIE D65 illuminant and the L*a*b* values were determined. The color matching abilities to artificial teeth were evaluated using the ΔE*ab and ΔE00 color difference formulas. One-way analysis of variance and Tukey's post hoc test were used. The spectral reflectance of experimental composites showed different trends in different backgrounds, plate thickness, and filler contents. In particular, higher spectral reflectance was observed on the white background at wavelengths ranging from 450 to 700 nm in both 1.5 and 3.0 mm plates when compared to the black background. The percent reflectivity tended to decrease with a decrease of the filler contents. The color matching abilities of the experimental composites improved with the increase in the filler contents. Conclusions Structural coloration of the flowable resin composites were affected by the filler contents. Clinical significance Clinical Significance: Higher filler contents might be needed to achieve the optimal color properties of structural colored flowable resin composites, thereby improving the restoration esthetics.

Intraparotid facial nerve schwannoma, an uncommon tumor documented sporadically in medical literature, must be differentiated from pleomorphic adenoma. Function-preserving surgical resection is also important. We report a case of intraparotid facial nerve schwannoma in a 42 year-old woman seen for a right parotid gland tumor 28 mm in diameter. Computed tomography (CT) and Magnetic resonance imaging (MRI) showed a noninvasive round mass between the tip of the mastoid process and the mandibular condyloid process. Fine-needle aspiration cytology confirmed a benign mass consisting of histiocytes or interstitial cells, although preoperative tests could not differentiate schwannoma from pleomorphic adenoma. Surgical exploration found a yellow encapsulated mass arising in the main facial nerve trunk and the nerve funiculus extending into the capsule. A surgeon diagnosed a facial neurogenic tumor, which was resected intracapsularly leaving no tumor tissue in surgical microscopy. Postoperative facial palsy eventually disappeared, completely restoring facial nerve function. No recurrence has been seen in the 7 years and 8 months since surgery, indicating that intracapsular resection may be an intraparotid schwannoma treatment providing a favorable prognosis.

The integral roles of heat shock proteins (hsps) in the cell cycle and in multistep processes leading to tumorigenesis have been implied. We examined the expression of hsp90alpha, hsp90beta and cyclin D1 in human breast cancer. Levels of mRNAs coding for hsp90alpha and cyclin D1 were significantly higher in cancer tissues than in non-cancer tissues. Moreover, there was a close relationship between the extent of the two mRNA levels, suggesting that increased expression of hsp90alpha, an isoform of the hsp90 family, is associated with the proliferation of human breast cancer. Hsp90beta was expressed in cancer cells, but not associated with cell proliferation.

A case of a desmoplastic small cell tumor of the large omentum associated with gross ascites that occurred in a male adolescent is reported. Light microscopic studies revealed that the tumor cells were small and epithelioid in nature with eosinophilic hyaline material located in the perinuclear area. They were surrounded by rich desmoplastic and myxoidal stromal bands. Immunohistochemical staining revealed globoid perinuclear positivity for desmin. Vimentin, cytokeratin (AE3, CaM 5.2), epithelial membrane antigen, tissue polypeptide antigen, neuron-specific enolase, chromogranin A, endocrine granule constituent and synaptophysin were also positive in the cytoplasm. Electron microscopy revealed whorled intermediate filaments and some dense core granules in the cytoplasm. Bundles of microtubules in the cytoplasmic process and occasional cell junctions of zonulae adherentes in the tumor cells were also observed. DNA analysis of the tumor cells showed the three-fold amplification of the N-myc gene. Although desmoplastic small cell tumors showed a heterogeneous pattern with immunohistochemical studies, it is suggested that the tumor may originate from neurogenic cells.

Cathepsin B, which was originally found to be a lysosomal cysteine protease, is also an important matrix protease. In this study, we investigated the expression of cathepsin B and cystatin C, the strongest inhibitor of cathepsin B, and measured the relative amounts of each in human breast cancer tissues. Cystatin C expression relative to cathepsin B expression was found to be decreased. This finding could be associated with the looseness of cancerous interstitial tissue, which might play a role in cancer invasion and metastasis. This report documents the first simultaneous investigation of cathepsin B and cystatin C in breast cancer tissues.