The Effects of Aluminablasting on Bond Durability Between Universal Adhesives and Tooth Substrate.

The aim of this study was to determine the effect of aluminablasting on the bond durability of universal adhesives and adherent surface characteristics. Adhese Universal (Ivoclar Vivadent), All-Bond Universal (Bisco), Bondmer Lightless (Tokuyama Dental), G-Premio Bond (GC), and Scotchbond Universal (3M ESPE) were used in self-etch mode. The prepared bovine enamel and dentin specimens were divided into two groups based on whether they received an aluminablasting prior to application of the universal adhesives. The resin composite bonded specimens were stored in distilled water at 37°C for 24 hours, following which the shear bond strength (SBS) of half of the specimens was measured (24-hour group). The other half was subjected to 30,000 thermal cycles between 5 and 55°C before SBS measurement (TC group). Surface roughness (Ra) and surface free energy (SFE) of the adherent surfaces were also measured, and scanning electron microscopy observation and scanning electron microscopy/energy-dispersive X-ray analysis were carried out. Most of the adhesives did not show any significant differences in enamel SBS values between the two pretreatment groups, regardless of the storage condition. However, the dentin SBS values were significantly lower in specimens that underwent aluminablasting compared with those that did not, irrespective of their storage conditions. Significantly higher Ra and SFE values were observed in the enamel and dentin of specimens that underwent aluminablasting. Although aluminablasting increased the Ra and SFE values of enamel and dentin, its effect on the SBS value was dependent on the tooth substrate. In addition to C, O, Na, Mg, P, and Ca, the element Al was detected in the enamel and dentin of samples that had undergone aluminablasting. These results suggest that although aluminablasting of the tooth surface is thought to be effective for modification of the adherent surface, it may not enhance enamel bond performance and may also adversely affect the dentin bond effectiveness of the universal adhesives.

In vitro analysis of blood flow in a microvascular network with realistic geometry.

In vitro blood flow was measured in a polydimethysiloxane micro channel to reflect the complex geometry of a microvascular network. Flow rates were determined from the velocities of tracer particles moving along the center line of the flow channel, and the flow rates of two working fluids were then compared: water and blood. In some bifurcating channels, the measured flow rate showed that the effects of bifurcation in the apparent viscosity depend on the hematocrit, such that the flow rate in the daughter channel with the higher (lower) flow rate was lower (higher) for blood than for water. The measured flow rates in other bifurcating channels reflected effects from the surrounding flow channels acting as bypasses, which tended to balance out the effects of bifurcation.

Bilberry extract supplementation for preventing eye fatigue in video display terminal workers.

OBJECTIVES: To examine the effect of a dietary supplement containing bilberry extract (BE) on eye fatigue induced by acute video display terminal (VDT) loads. DESIGN AND SETTING: A prospective, randomized, double-blind, placebo-controlled study was performed from August 2012 to February 2013 in the Medical Corporation Jico-kai Yagi Hospital, and the Shinyokohama Shinoharaguchi Orthopedic Surgery and Dermatology Clinic, in Japan. PARTICIPANTS: Two hundred eighty-one office workers aged 20-40 years that used VDTs were screened by critical flicker fusion (CFF) and near point accommodation (NPA). INTERVENTION: The participants were randomized to either a BE (480 mg/day) or placebo (vehicle) group, and took allocated capsule, daily, for 8 weeks. MEASUREMENTS: The CFF, NPA, contrast visual acuity, functional visual acuity, keratoconjunctival epithelial damage, and fluorescein tear film break-up time were examined, and 18 subjective symptoms of eye fatigue were evaluated by questionnaire. Adverse events were reported via medical interviews. Data were collected both before and after VDT load at baseline, and 4, and 8 weeks after daily supplementation with either BE or placebo. RESULTS: Of 281 participants screened, 88 having relatively lower levels of CFF and NPA were enrolled in the study. Of these, 37 control and 43 BE group subjects completed the study. The VDT load-induced reduction in CFF was alleviated after 8 weeks of BE supplementation (95% confidence interval, 0.10-1.60; p=0.023), in contrast to placebo supplementation, while NPA variation was not. Of the subjective symptoms of eye fatigue, VDT load-induced ocular fatigue sensation, ocular pain, eye heaviness, uncomfortable sensation, and foreign body sensation were mitigated more in the BE group than in the control group, at week 8 (p<0.05). There were no severe adverse events in either group. CONCLUSIONS: BE supplementation improved some of the objective and subjective parameters of eye fatigue induced by VDT loads.

Influence of light intensity on surface free energy and dentin bond strength of core build-up resins.

OBJECTIVE: We examined the influence of light intensity on surface free energy characteristics and dentin bond strength of dual-cure direct core build-up resin systems. METHODS: Two commercially available dual-cure direct core build-up resin systems, Clearfil DC Core Automix with Clearfil Bond SE One and UniFil Core EM with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in acrylic resin and the facial dentin surfaces were wet ground on 600-grit silicon carbide paper. Adhesives were applied to dentin surfaces and cured with light intensities of 0 (no irradiation), 200, 400, and 600 mW/cm(2). The surface free energy of the adhesives (five samples per group) was determined by measuring the contact angles of three test liquids placed on the cured adhesives. To determine the strength of the dentin bond, the core build-up resin pastes were condensed into the mold on the adhesive-treated dentin surfaces according to the methods described for the surface free energy measurement. The resin pastes were cured with the same light intensities as those used for the adhesives. Ten specimens per group were stored in water maintained at 37°C for 24 hours, after which they were shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. Two-way analysis of variance (ANOVA) and a Tukey-Kramer test were performed, with the significance level set at 0.05. RESULTS: The surface free energies of the adhesive-treated dentin surfaces decreased with an increase in the light intensity of the curing unit. Two-way ANOVA revealed that the type of core build-up system and the light intensity significantly influence the bond strength, although there was no significant interaction between the two factors. The highest bond strengths were achieved when the resin pastes were cured with the strongest light intensity for all the core build-up systems. When polymerized with a light intensity of 200 mW/cm(2) or less, significantly lower bond strengths were observed. CONClUSIONS: The data suggest that the dentin bond strength of core build-up systems are still affected by the light intensity of the curing unit, which is based on the surface free energy of the adhesives. On the basis of the results and limitations of the test conditions used in this study, it appears that a light intensity of >400 mW/cm(2) may be required for achieving the optimal dentin bond strength.

Improvement of accommodation with anti-oxidant supplementation in visual display terminal users.

OBJECTIVE: To determine the antioxidant supplementation effect on accommodation among VDT users. DESIGN: A double blind randomized placebo controlled study. Registered under ClinicalTrials.gov Identifier No. NCT00877201. PARTICIPANTS AND CONTROLS: Fourty right eyes of 40 healthy VDT users (30 females, 10 males, mean age: 43.8±2.8 years, range: 40-49 years). 20 subjects (15 females, 5 males; mean age: 44.0±2.7 years, range: 40-49 years). METHODS: Subjects were required to take an antioxidant supplement, 20 age and sex matched subjects (15 females, 5 males; mean age: 43.6±3.1 years, range: 40-49 years) were required to take placebo medication for 4 weeks. RESULTS: The mean of the change in accommodation power was significantly higher in the group receiving antioxidant supplements (0.20±0.50 Diopter(D)) compared to the placebo group (-0.12±0.48(D)) (p<0.05). CONCLUSIONS: Antioxidant supplementation was observed to improve accommodation in Japanese Visual Display Terminal (VDT) Users.

Surgical management of lacrimal punctal cauterization in chronic GVHD-related dry eye with recurrent punctal plug extrusion.

We investigated the efficacy of lacrimal punctal occlusion surgery with a cautery device in patients with chronic GVHD (cGVHD)-related dry eye, with recanalization of puncta and recurrent punctal plug extrusion. A total of 23 puncta from 14 eyes of 10 patients with chronic GVHD (cGVHD)-related dry eye underwent punctual thermal cauterization with a high-temperature disposable cautery device. All patients were refractory to conventional treatment, including artificial tear eye drops, autologous serum eye drops and vitamin A eye drops, and had a history of recanalization and recurrent punctal plug extrusion. The effect of lacrimal punctal cauterization by thermal cautery device was evaluated by changes in subjective symptom scores, corrected distance visual acuity, Schirmer's test values, fluorescein staining scores, rose bengal staining scores, and tear-film break-up time before and 3 months after the surgery. Subjective symptom scores, Schirmer's test values, fluorescein and rose bengal scores, and tear-film break-up time improved significantly 3 months after the surgery. Recanalization of puncta was not observed in all the cases (0 of 14 eyes, 0%). Lacrimal punctal cauterization was effective with no recanalization and significant improvements in subjective symptoms and the ocular surface environment in cGVHD-related dry eye patients who had been refractory to conventional treatments.

Mucosal microvilli in dry eye patients with chronic GVHD.

The ocular surface is a frequent target tissue of mucosal chronic GVHD (cGVHD). We investigated the histopathological features of the conjunctival microvilli in patients with cGVHD. Conjunctival tissue specimens from patients with cGVHD or Sjögren's syndrome (SS) or from healthy individuals were examined by light microscopy and EM, impression cytology, and immunohistochemistry. The cGVHD conjunctivae showed significantly more metaplasia and fewer goblet cells than the SS and normal conjunctivae. Abundant CD8(+) T cells infiltrated the basal epithelia in the cGVHD conjunctiva. The microvilli per standard epithelial unit and the secretory vesicles were counted by analyzing electron micrographs. The mean number of mucosal microvilli was significantly lower in the cGVHD than that in the SS or normal specimens, and the microvilli were significantly shorter, with a smaller height-width ratio. The mean number of secretory vesicles was also significantly lower, and the membrane-spanning mucin thinner, in the cGVHD compared with the SS and normal specimens. Thus, the conjunctival mucosal microvilli of cGVHD patients were significantly different in number and morphology from those of SS and normal subjects. These may be important factors affecting the stability of the tear-film layer and its contribution to cGVHD-related dry eye.

Donor-recipient gender difference affects severity of dry eye after hematopoietic stem cell transplantation.

PURPOSE: To determine whether the incidence rate and severity of dry eye after hematopoietic stem cell transplantation varies with donor vs recipient gender. METHODS: We limited this study to patients received bone marrow transplantation (BMT). In all, 172 patients received BMT at Keio University School of Medicine between January 2000 and May 2007. Of them, 136 recipients who survived at least 70 days were studied prospectively. We classified the 136 patients according to the gender of the donor and the recipient (group I: female to female; group II: male to male; group III: male to female; group IV: female to male). The incidence and severity of chronic graft-vs-host disease-associated dry eye were determined for each group. The donor gender was masked when we assessed dry eye and calculate the incidence. RESULTS: The incidence of dry eye was 47.4% for group I, 37.5% for group II, 58.6% for group III, and 42.9% for group IV. The percentage of patients with severe dry eye was 44.4, 50.0, 35.3, and 77.8% respectively. There was a significant difference between the percent severe dry eye/total dry eye incidences in groups III and IV (P=0.0375) (odds ratio, 7.6; 95% confidence interval, 1.00-101.01). CONCLUSIONS: Close attention must be paid to the development of dry eye in cases of female to male BMTs, because the ratio of severe/total dry eye is more common in cases of female to male BMTs than in other gender combination.

Neurodegenerative influence of oxidative stress in the retina of a murine model of diabetes.

AIMS/HYPOTHESIS: Diabetic retinopathy is a progressive neurodegenerative disease, but the underlying mechanism is still obscure. Here, we focused on oxidative stress in the retina, and analysed its influence on retinal neurodegeneration, using an antioxidant, lutein. METHODS: C57BL/6 mice with streptozotocin-induced diabetes were constantly fed either a lutein-supplemented diet or a control diet from the onset of diabetes, and their metabolic data were recorded. In 1-month-diabetic mice, reactive oxygen species (ROS) in the retina were measured using dihydroethidium and visual function was evaluated by electroretinograms. Levels of activated extracellular signal-regulated kinase (ERK), synaptophysin and brain-derived neurotrophic factor (BDNF) were also measured by immunoblotting in the retina of 1-month-diabetic mice. In the retinal sections of 4-month-diabetic mice, histological changes, cleaved caspase-3 and TUNEL staining were analysed. RESULTS: Lutein did not affect the metabolic status of the diabetic mice, but it prevented ROS generation in the retina and the visual impairment induced by diabetes. ERK activation, the subsequent synaptophysin reduction, and the BDNF depletion in the diabetic retina were all prevented by lutein. Later, in 4-month-diabetic mice, a decrease in the thickness of the inner plexiform and nuclear layers, and ganglion cell number, together with increase in cleaved caspase-3- and TUNEL-positive cells, were avoided in the retina of lutein-fed mice. CONCLUSIONS/INTERPRETATION: The results indicated that local oxidative stress that has a neurodegenerative influence in the diabetic retina is prevented by constant intake of a lutein-supplemented diet. The antioxidant, lutein may be a potential therapeutic approach to protect visual function in diabetes.

Baseline profiles of ocular surface and tear dynamics after allogeneic hematopoietic stem cell transplantation in patients with or without chronic GVHD-related dry eye.

We evaluated ocular surface alterations in allogeneic hematopoietic stem cell transplantation (HSCT) recipients with or without chronic GVHD-related dry eye in a prospective study. Fifty eyes of 25 post-HSCT patients and 28 eyes of 14 age-matched healthy controls were included. Meibomian gland (MG) obstruction, tear evaporation rate, corneal sensitivity (CS), Schirmer test-I, tear break-up time (BUT) and ocular surface vital staining were examined. Conjunctival impression and brush cytology specimens were collected to evaluate the goblet cell density (GCD) and the inflammatory cell numbers. Obvious MG obstruction, decreased CS and enhanced tear evaporation rate were found in post-HSCT patients compared with normal controls. In addition, decreased conjunctival GCD, increased conjunctival squamous metaplasia and inflammatory cells were noted in cGVHD-related dry eyes compared with normal controls and post-HSCT without dry eye subjects. Furthermore, the conjunctival inflammatory cells were significantly higher in severe dry eyes compared with mild dry eyes (P=0.03). We found comprehensive ocular surface alteration in post-HSCT patients, regardless of whether they had cGVHD-related dry eye or not. The results suggest that the extent of inflammatory process seems to have a pivotal role in the outcome of the cGVHD-related dry eye.

Topical tranilast for treatment of the early stage of mild dry eye associated with chronic GVHD.

Fibrosis and excessive extracellular matrix production are characteristic features of lacrimal gland chronic GVHD (cGVHD). Tranilast (n-[3,4-anthoranilic acid]), used for fibrotic skin disease, inhibits transforming growth factor-beta-induced matrix production. We conducted a non-randomized study comparing 8 patients (five men, three women; median age, 47 years) given topical tranilast with 10 patients (three men, seven women; median age, 37 years) receiving therapy with topical artificial tears, sodium hyaluronate and vitamin A for mild ocular cGVHD. The tranilast group instilled topical tranilast and artificial tears q.i.d., beginning the day of dry eye diagnosis. The ocular surface and tear dynamics of each patient were evaluated before hematopoietic stem cell transplant, at the onset of dry eye and after 3 months of treatment. At 3 months, the scores of the Rose Bengal test and Schirmer test with nasal stimulation had significantly improved in the tranilast group compared with that in the control group (P<0.05). Furthermore, although five control patients (50%) developed severe dry eye within the treatment period, only one tranilast-treated patient (12.5%) did; the rest still had mild dry eye (P<0.05). These results suggest the hypothesis that topical tranilast may effectively retard the progression of mild dry eye associated with cGVHD.

Turnover rate of tear-film lipid layer determined by fluorophotometry.

AIM: This study was performed to independently assess the turnover rates of aqueous and lipid layers of the tear film. METHODS: Two fluorescent dyes, fluorescein sodium and 5-dodecanoylaminofluorescein (DAF), which is a free-fatty-acid conjugate of fluorescein, were applied to the right eye of 12 healthy volunteers. Fluorescent intensity of the precorneal tear film was measured at the central cornea every minute for 10 min for fluorescein sodium, and every 5 min for 50 min for DAF. The turnover rate was calculated by plotting fluorescent intensity against time in a semilog plot and expressed as %/min. RESULTS: Turnover rates of fluorescein sodium and DAF were 10.3 (SD 3.7)%/min and 0.93 (0.36)%/min, respectively. The turnover rate of DAF was significantly lower than that of fluorescein sodium (p<0.05, Mann-Whitney test). The turnover rate of DAF positively correlated with that of fluorescein sodium (r = 0.93, p<0.05). CONCLUSION: Our results indicate that the turnover of lipids in tears is much slower than the aqueous flow of tears, and that this lipid turnover is associated with the aqueous flow of tears in healthy adults.

Proposal for a new clinical entity, IgG4-positive multiorgan lymphoproliferative syndrome: analysis of 64 cases of IgG4-related disorders.

BACKGROUND: Mikulicz's disease (MD) has been considered as one manifestation of Sjögren's syndrome (SS). Recently, it has also been considered as an IgG(4)-related disorder. OBJECTIVE: To determine the differences between IgG(4)-related disorders including MD and SS. METHODS: A study was undertaken to investigate patients with MD and IgG(4)-related disorders registered in Japan and to set up provisional criteria for the new clinical entity IgG(4)-positive multiorgan lymphoproliferative syndrome (IgG(4)+MOLPS). The preliminary diagnostic criteria include raised serum levels of IgG(4) (>135 mg/dl) and infiltration of IgG(4)(+) plasma cells in the tissue (IgG(4)+/IgG+ plasma cells >50%) with fibrosis or sclerosis. The clinical features, laboratory data and pathologies of 64 patients with IgG(4)+MOLPS and 31 patients with typical SS were compared. RESULTS: The incidence of xerostomia, xerophthalmia and arthralgia, rheumatoid factor and antinuclear, antiSS-A/Ro and antiSS-B/La antibodies was significantly lower in patients with IgG(4)+MOLPS than in those with typical SS. Allergic rhinitis and autoimmune pancreatitis were significantly more frequent and total IgG, IgG(2), IgG(4) and IgE levels were significantly increased in IgG(4)+MOLPS. Histological specimens from patients with IgG(4)+MOLPS revealed marked IgG(4)+ plasma cell infiltration. Many patients with IgG(4)+MOLPS had lymphocytic follicle formation, but lymphoepithelial lesions were rare. Few IgG(4)+ cells were seen in the tissue of patients with typical SS. Thirty-eight patients with IgG(4)+MOLPS treated with glucocorticoids showed marked clinical improvement. CONCLUSION: Despite similarities in the involved organs, there are considerable clinical and pathological differences between IgG(4)+MOLPS and SS. Based on the clinical features and good response to glucocorticoids, we propose a new clinical entity: IgG(4)+MOLPS.

Tear function and lipid layer alterations in dry eye patients with chronic graft-vs-host disease.

PURPOSE: To investigate the changes in the tear film lipid layer in haematopoietic stem cell transplantation (HSCT) patients with dry eye (DE) associated with chronic graft-vs-host disease (cGVHD) and compare with HSCT recipients without DE. METHODS: We performed a prospective study in 10 HSCT patients with DE associated with cGVHD and 11 HSCT recipients without DE. We performed Schirmer's test, tear film break up time examinations, ocular surface dye staining and meibum expressibility test and DR-1 tear film lipid layer interferometry. DR-1 interferometry images of the tear film surface were assigned a 'DR-1 grade' according to the Yokoi severity grading system. The DR-1 grades were analysed according to the presence or absence of DE, conjunctival fibrosis and systemic cGVHD. RESULTS: The mean DR-1 severity grade in patients with DE related to cGVHD (DE/cGVHD group; 3.9+/-0.9) was significantly higher than in patients without DE after HSCT (non-DE/non-cGVHD group; 1.3+/-0.6; P<0.05). The DR-1 grade for HSCT recipients with conjunctival fibrosis was significantly higher than in patients without conjunctival fibrosis (P<0.05). When DE severity was graded according to the recommendation of the 2007 Dry Eye Workshop Report, our results showed a correlation between the severity of DE and DR-1 grades (r=0.8812, P<0.0001). CONCLUSION: DR-1 interferometry may be applicable to diagnosing DE and evaluating its progression subsequent to HSCT.

Measurement of fornix depth and area: a novel method of determining the severity of fornix shortening.

PURPOSE: To measure the depth and area of the fornix in normal adults and patients with symblepharon. METHODS: The fornix depth of normal eyes (n=20) and patients with symblepharon (Stevens-Johnson syndrome, n=4) was measured at six locations in each eye using non-invasive, dull-edged stainless steel metric scale. Before and after conjunctival reconstruction surgery, the depths of fornix were also measured by the same method. The overall area was assessed from those fornix depth at six points. RESULTS: The mean depths of the superior nasal and temporal, inferior nasal and temporal, fornices as well as mean depths of medial nasal and temporal canthi fornices in normal eyes were 14.1+/-2.5, 14.1+/-2.5, 10.0+/-2.1, 10.4+/-1.8, 3.0+/-0.9, and 5.2+/-1.2 mm, respectively. The mean overall area of the conjunctival fornix in normal subjects was 909.6+/-162.2 mm(2). All these parameters were significantly lower in the eyes of patients. Both depth and area after surgery were significantly deeper and larger than before. CONCLUSIONS: This estimation may prove useful when evaluating the severity of symblepharon and determining the post-surgical prognosis.

Alterations of the ocular surface epithelial MUC16 and goblet cell MUC5AC in patients with atopic keratoconjunctivitis.

BACKGROUND: An increased understanding of the ocular surface at cellular level in the conjunctiva and the cornea may help explain the pathogenesis and the subsequent clinical appearance of atopic ocular allergies, which may be potentially blinding. PURPOSE: To investigate the MUC16 and MUC5AC alterations, tear function and the ocular surface disorder in patients with atopic keratoconjunctivitis (AKC). METHODS: Thirty-six eyes of 18 AKC patients as well as 28 eyes of 14 age- and sex-matched normal subjects were studied. The subjects underwent corneal sensitivity measurements, Schirmer test, tear film break-up time (BUT), fluorescein and Rose-Bengal staining of the ocular surface, conjunctival impression cytology and brush cytology. Impression cytology samples underwent periodic acid schiff and immunohistochemical staining with MUC16 and MUC5AC antibodies. Brush cytology specimens underwent evaluation for inflammatory cell numbers and quantitative real-time polymerase chain reaction (PCR) for MUC16 and MUC5AC mRNA expression. RESULTS: The mean corneal sensitivity and BUT values were significantly lower in patients with AKC, compared with controls (P < 0.001). Brush cytology specimens from AKC patients revealed significantly higher numbers of inflammatory cells (P < 0.001). Specimens from patient eyes showed positive staining for MUC5AC and MUC16. MUC16 mRNA expression was significantly upregulated with significant downregulation of MUC5AC mRNA expression in eyes with AKC compared with the eyes of control subjects. CONCLUSION: Ocular surface inflammation, decline in corneal sensitivity, tear film instability, changes in conjunctival epithelial MUC5AC and MUC16 mRNA expressions were thought to be important in the pathogenesis of atopic ocular surface disease.