Bond strength between four luting systems and enamel modified with phosphoric acid

The purpose of this study was to investigate the effect of phosphoric acid etching on the bond strength between enamel and three luting materials employing self-etching primer (PanaviaF2.0, Linkmax, and Multibond). A luting material without self-etching primer (Super-Bond) was used as a control. Two etching agents (K-etchant and Red Activator) were prepared. The surfaces of bovine enamel were ground, etched with either K-etchant or Red Activator, and then bonded to a stainless steel rod. Tensile bond strengths were determined following 24-hour immersion in water. Without etching, all of the luting materials showed the same statistical bond strength. When K-etchant was applied, the bond strengths of PanaviaF2.0, Linkmax, Multibond, and Super-Bond were significantly greater than that of non-etched control. No significant differences were found between K-etchant and Red Activator. Strongest bonds were obtained for Super-Bond in conjunction with K-etchant (23.6 +/- 6.3 MPa) or Red Activator (21.0 +/- 6.5 MPa), whereby the values were statistically comparable.     

Effect of double-application of all-in-one adhesives on dentin bonding

OBJECTIVES: To evaluate the effect of double-application of all-in-one adhesives using the micro-shear bond test. METHODS: The occlusal surfaces of extracted human third molars were ground perpendicular to the long axis of each tooth to expose a flat dentin surface. Three commercially available and one experimental bonding system were used in this study: Adper Prompt L-Pop (APL, 3M ESPE), REACTMER BOND (RB, Shofu), XENO III (Xeno, Dentsply-Sankin) and newly developed OBF-2 (OB2, Tokuyama Dental). These adhesives were applied on the dentin surfaces by either the manufacturers' instructions or by an experimental method (single-application or double-application). Resin composite was then placed and light-cured for 40s. After 24h immersion in water, a micro-shear bond test was carried out and the fractured dentin surfaces were observed microscopically. The data were analyzed by one-way ANOVA and Tukey's HSD tests (p<0.05). RESULTS: The mean bond strengths of APL, RB, Xeno and OB2 with single-application were 22.7, 28.3, 30.3 and 34.6MPa, respectively. The mean bond strengths of APL, RB, Xeno and OB2 with double-application were 29.5, 27.2, 29.6 and 32.5MPa, respectively. There were no statistically significant differences in micro-shear bond strengths between the single- and double-application methods for each adhesive system (p>0.05). The morphological observation of the fractured dentin surfaces revealed differences between the single- and double-application groups especially for APL and OB2. CONCLUSIONS: Micro-shear bond strengths of all-in-one adhesives in this study showed no statistically significant differences between the single-application and the double-application method.     

Application of a preliminary light-curing unit for enhanced bonding between a gold alloy and veneering materials

PURPOSE: To evaluate the effectiveness of a preliminary light-curing unit when it was used in a procedure to bond veneering material to metal. METHODS: Two light-activated composite materials (Artglass and Cesead II) were separately placed onto gold alloy disks (Pontol LFC), and polymerized using one of the following three methods: (1) exposure with a high-intensity laboratory light-curing unit (Hyper LII) for 90 seconds; (2) exposure with a preliminary light-curing unit (Targis Quick) for 20 seconds, followed by exposure with the high-intensity unit for 90 seconds; and (3) exposure with the preliminary unit for 90 seconds, followed by exposure with the high-intensity unit for 90 seconds. Shear bond strengths were determined and compared by analysis of variance and post-hoc multiple comparison intervals. The curing depths of the two materials polymerized with the two curing units were determined using a scraping technique described by the International Organization for Standardization (ISO) 4049 with the aim of evaluating the difference in curing performance between the two units. RESULTS: The group polymerized using the preliminary unit for 90 seconds showed statistically improved bond strengths over the group polymerized without the preliminary unit (P < 0.05) regardless of the materials. Regarding the Cesead II material, both groups polymerized using the preliminary unit also indicated significantly improved bond strength compared with the group polymerized with high-intensity only. Also, curing depth results revealed that the high-intensity unit demonstrated greater curing performance than the preliminary unit for both types of materials examined.     

Evaluation of the relationship between periapical lesions/sclerotic bone and general bone density as a possible gauge of general health among 80-year-olds

OBJECTIVES: To evaluate the incidence among 80-year-olds of periapical lesions as detected on panoramic radiographs and to determine the relationship between sclerotic bone around the periapical lesions to heel bone density, body height, and hand-grip strength. STUDY DESIGN: Six hundred fifty-nine panoramic radiographs (262 males, 397 females), obtained from 80-year-old residents of Fukuoka Prefecture, Japan, were used for evaluation of periapical lesions. These findings were correlated with physical examination results to determine the relationship to general health. RESULTS: Of 659 panoramic radiographs, 31 (5%) were noted to have periapical lesions. Average size of the 31 periapical lesions was 6.1 +/- 2.2 mm. Of the 31 periapical lesions, 21 (68%) were accompanied by linear or diffuse types of sclerotic bone. Of the 21 sclerotic bones, 10 (48%) were of a linear type of sclerotic bone and 11 (52%) of a diffuse type of sclerotic bone. Of the 11 diffuse types of sclerotic bone, 10 (91%) were in the mandible and 1 (9%) in the maxilla. Periapical lesions in the mandible were more frequently accompanied by a diffuse type of sclerotic bone than those in the maxilla (P < .01). The hand-grip strength of those having periapical lesions, accompanied by a diffuse type of sclerotic bone, was stronger than those having no periapical lesions (P < .01) and those accompanied by a linear type of sclerotic bone (P < .03). However, there was no relationship between presence of sclerotic bone and heel bone density or body height. CONCLUSIONS: Periapical lesions accompanied by a diffuse type of sclerotic bone were more frequently seen in the mandible of 80-year-olds. To evaluate the clinical significance of sclerotic bone around periapical lesions in 80-year-olds, further study to evaluate the significance of endodontic treatment needs to be done.     

Weekly paclitaxel in the treatment of advanced or metastatic breast cancer previously treated or not treated with docetaxel: a phase II study

BACKGROUND: Paclitaxel has been approved for 3-weekly administration in Japan. Recent reports suggest that weekly paclitaxel can achieve a higher tumor response and lower toxicity. METHODS: This study was designed to investigate the usefulness and tolerability of weekly paclitaxel by 1-hour infusion in patients with metastatic breast cancer who were previously treated with docetaxel or other anticancer agents. RESULTS: Thirty-five patients were enrolled. The overall response rate was 41.2% (14/34, 95% confidence interval: 24.6-59.3%). The median time to progression and the median survival time were 218.5 and 624 days, respectively. One patient developed dyspnea, probably induced by a hypersensitivity reaction. The most common hematological toxicities were leukopenia and neutropenia, although no patients developed grade 4 leukopenia or neutropenia and G-CSF support was not required. CONCLUSIONS: Weekly paclitaxel could be safely administered and achieved a relatively high response rate. Weekly paclitaxel would be a good candidate second-line therapy for recurrent or advanced breast cancer.     

Prediction of efficacy of interferon treatment of chronic hepatitis C and occurrence of HCC after interferon treatment by a new classification

One hundred and twenty-one chronic hepatitis C patients were administered interferon (IFN) and divided into two groups: 31 complete responders (CR) with prolonged HCV-RNA negative 1 year after treatment and 90 non-complete responders (non-CR), including partial responders (PR) with transiently negative HCV-RNA and non-responders (NR) with continuously positive HCV-RNA. Liver biopsy specimens were classified into four grades and stages according to the degree of severity and the extent of fibrosis, respectively. No correlation was observed between the rate of IFN efficacy and grading. By staging, however, a difference in the efficacy of IFN was observed between F1 or F2 and F3 (0.05 < p < 0.1 and 0.01 < p < 0.025, respectively). Of the CR, 0% (0/5) were at F0 and 27.9% (24/86) at F1, 42.9% (6/14) at F2, and 6.3% (1/16) at F3. Another group of 118 chronic hepatitis patients (31 CR, 41 PR and 46 NR) followed up for over 2 years after IFN treatment were analyzed. By staging, 7 cases were at F0, 76 at F1, 18 at F2, and 17 at F3. HCC occurred in 1 of the 31 CR cases (representing an annual incidence rate of 1.21%), in 4 of the 41 PR cases (4.08%), and in 4 of the 46 NR cases (3.55%). HCC did not occur in any of the 7 cases at F0 (representing an annual incidence rate of 0%); it occurred in 2 of the 76 cases at F1 (1.01%), in 1 of the 18 cases at F2 (2.28%), and in 6 of the 17 cases at F3 (16.57%). These results suggest that the new classification would be conducive to roughly predicting the efficacy of IFN treatment and the occurrence of HCC after IFN treatment.