Shear bond strength of four different repair materials applied to bis-acryl resin provisional materials measured 10 minutes, one hour, and two days after bonding.

This study investigated the shear bond strength of repaired provisional restoration materials 1) to compare the bond strengths between bis-acryl resin and four different materials and 2) to investigate the effect of the amount of time elapsed after bonding on the bond strength. The self-cured bis-acryl resin (Luxatemp) was used as the base material, and four different types of resins (Luxatemp, Protemp, Z350 flowable, and Z350) were used as the repair materials. Specimens were divided into three groups depending on the point of time of shear bond strength measurement: 10 minutes, one hour, and 48 hours. Shear bond strengths were measured with a universal testing machine, and the fracture surface was examined with a video measuring system. Two-way analysis of variance revealed that the repair materials (p<0.001) and the amount of time elapsed after bonding (p<0.001) significantly affected the repair strength. All of the repaired materials showed increasing bond strength with longer storage time. The highest bond strength and cohesive failure were observed for bonding between Luxatemp base and Luxatemp at 48 hours after bonding.

Maintenance anaesthetics during remifentanil-based anaesthesia might affect postoperative pain control after breast cancer surgery.

BACKGROUND: Although remifentanil provides profound analgesia during operation, postoperative occurrence of hyperalgesia and tolerance after remifentanil administration could be a challenge to the postoperative pain control. In this investigation, we sought to determine the effect of maintenance with propofol or sevoflurane on postoperative analgesia after remifentanil-based anaesthesia. METHODS: Two hundred and fourteen women undergoing breast cancer surgery under remifentanil-based general anaesthesia were randomly included in this prospective and double-blind trial. The patients were anaesthetized with sevoflurane (S) or propofol (P) under high (H) or low (L) effect-site concentration (Ce) of remifentanil-based anaesthesia using a target-controlled infusion system; the patients were allocated into the SH, SL, PH, and PL groups. Pain intensity (visual analogue score, VAS) and cumulative morphine requirements were recorded 30 min, 1, 6, 12, and 24 h after operation. RESULTS: The patient characteristics were similar. Cumulative morphine consumption at 24 h after surgery was higher in the SH group [38.6 (sd 14.9)] compared with the SL [31.5 (3.7)], PH [31.7 (8.3)], and PL groups [30.1 (6.1)] (P<0.001). The VAS scores during 24 h after surgery were also higher in the SH group than the SL, PH, and PL groups (P<0.001). CONCLUSIONS: Remifentanil hyperalgesia was induced by high dose of remifentanil-based anaesthesia during sevoflurane anaesthesia, whereas that was not apparent during propofol anaesthesia. Also, remifentanil hyperalgesia did not occur during low dose of remifentanil-based anaesthesia. Maintenance of propofol during high-dose remifentanil-based anaesthesia provided better postoperative analgesia.

Effect of bone block graft with rhBMP-2 on vertical bone augmentation.

The effectiveness of vertical bone augmentation was evaluated in the cranial bone of 15 rabbits using a block of deproteinized bovine bone plus 10% porcine collagen (DBBB) and a cortico-cancellous human bone block (CHBB) with recombinant human bone morphogenetic protein-2 (rhBMP-2) in comparison with a guided bone regeneration (GBR) technique. The rabbits were divided into six groups: DBBB alone, DBBB/rhBMP-2, DBBB/membrane, CHBB alone, CHBB/rhBMP-2 and CHBB/membrane groups. After 12 weeks, the rabbits were killed. The CHBB groups showed higher values than the DBBB groups in terms of vertical height, the area of new bone fill and the maintained grafted area. In the CHBB groups, the CHBB/rhBMP-2 group revealed similar results to GBR. This animal study verifies that a CHBB with rhBMP-2 could be an alternative treatment option for vertical bone augmentation.

Effects of sevoflurane on collagen production and growth factor expression in rats with an excision wound.

BACKGROUND: Sevoflurane is a widely used inhalation anesthetic, but there are no studies on its effect on the wound-healing process. This study was undertaken to evaluate the effect of exposure time to sevoflurane on wound healing. METHOD: Male Sprague-Dawley rats were used. Two circular full-thickness skin defects 8 mm in diameter were made on the dorsum of the rats. The animals were divided into six groups according to exposed gas type and time: S1 (sevoflurane, 1 h), S4 (sevoflurane, 4 h), S8 (sevoflurane, 8 h), O1 (oxygen, 1 h), O4 (oxygen, 4 h), and O8 (oxygen, 8 h). The surface area of the wounds was measured 0, 1, 3, and 7 days after surgery. Separately, the mean blood pressures (MBP) and arterial oxygen pressures (PaO(2)) were monitored during the sevoflurane exposure. Collagen type I production and transforming growth factor-beta1 (TGF-beta1) and basic fibroblast growth factor (bFGF) expression on the wound surface were analyzed. Routine histological analysis was also performed. RESULT: Exposure duration to sevoflurane had no influence on MBP and PaO(2). The reduction in wound size and collagen type I production was delayed in S8. The expression of TGF-beta1 and bFGF on the wound surface in S8 was significantly attenuated in S8. The histology of the S8 demonstrated a delayed healing status. CONCLUSIONS: Prolonged exposure to sevoflurane might alter the inflammatory phase of the wound-healing process by attenuation of growth factor expression such as TGF-beta1 and bFGF and subsequently by reduced collagen production.

Preoperatively administered ramosetron oral disintegrating tablets for preventing nausea and vomiting associated with patient-controlled analgesia in breast cancer patients.

BACKGROUND AND OBJECTIVES: The purpose of this study was to investigate the acceptability and therapeutic efficacy of a preoperative single administration of long-acting 5-hydroxytryptamine type 3 (5-HT 3) receptor antagonist in an orally disintegrating tablet formulation, ramosetron, in breast cancer patients. METHODS: Two hundred and forty women, ASA I-II, aged 24-60 yr, undergoing elective breast cancer surgery, were randomized. A standardized anaesthetic technique was used. Patients were assigned to receive one of three treatment regimens (n = 80 in each group): no prophylactic antiemetics (Group A), single prophylactic intravenous injection of ramosetron 0.1 mg at the completion of surgery (Group B) or preoperatively oral administration of 0.1 mg of ramosetron (Group C). Episodes of nausea and vomiting, the use of rescue antiemetic treatment, degree of pain, adverse events and level of satisfaction were recorded. RESULTS: The overall incidence of nausea and vomiting during the first 24 h after the recovery in Groups B (27.8%) and C (25%) was decreased significantly compared with Group A (75.3%). The frequency of the use of rescue antiemetics was significantly lower in Group C (5.0%) compared with Groups A (53.2%) and B (15.2%). The patients in Group C were more satisfied with control of postoperative nausea and vomiting than others. CONCLUSION: Preoperative oral administration of ramosetron at a dose of 0.1 mg is an acceptable and effective way of reducing the incidence of postoperative nausea and vomiting in breast cancer patients.

Effect of proximal arterial occlusion on the progression of the distal arterial disease.

PURPOSE: To test the hypothesis that a proximal arterial occlusion has a protective effect on the progression of distal arterial disease, assessed by distal runoff resistance score (DRRS). MATERIALS AND METHODS: One hundred and nineteen patients (median age 64 y, male 96%) with a unilateral iliac and/or femoral arterial occlusion caused by atherosclerosis were analyzed retrospectively. DRRS was assessed on arteriograms of the test limb (with proximal arterial occlusion) and control limb (contralateral limb). Multivariate analysis was performed to determine if a proximal arterial occlusion was an independent risk factor for the development of a difference in the DRRS between the test and control limbs. RESULTS: The clinical features of the subjects were claudication in 85%, ankle brachial index 0.52 (median), diabetes in 30% and smoker in 76%. The upper leg DRRS of the test limb was significantly lower in the iliac occlusion group than in the control limb (1.87+/-1.69 vs 2.85+/-2.75, p=0.032). However, multivariate analysis failed to identify any risk factors associated with the difference in DRRS in both limbs. CONCLUSION: There was no evidence that a proximal arterial occlusion was associated with a slower progression of distal arterial disease.

Biological responses in osteoblast-like cell line according to thin layer hydroxyapatite coatings on anodized titanium.

Several features of the implant surface, such as roughness, topography and composition play a relevant role in implant integration with bone. This study was conducted in order to determine the effects of various thin layer hydroxyapatite (HA) coatings on anodized Ti surfaces on the biological responses of a human osteoblast-like cell line (MG63). MG63 cells were cultured on 100 nm HA (100 nm HA coating on anodized surface), 500-700 nm HA (500-700 nm HA coating on anodized surface), 1 mum HA (1 mum HA coating on anodized surface) and anodize (non-HA coating on anodized surface) Ti. The morphology of these cells was assessed by scanning electron microscopy (SEM). The cDNAs prepared from the total RNAs of the MG63 were hybridized into a human cDNA microarray (1152 elements). The appearances of the surfaces observed by SEM were different on each of the four dental substrate types. MG63 cells cultured on 100 nm HA, 1 mum HA and anodize exhibited cell-matrix interactions. It was 500-700 nm HA surface showing cell-cell interaction. In the expression of genes involved in osseointegration, several genes, including bone morphogenetic protein 2, latent transforming growth factor beta binding protein 1, catenin (cadherin-associated protein), integrin, PDGFRB and GDF-1 growth differentiation factor 1 were up-regulated on the different surfaces. Several genes, including fibroblast growth factor receptor 3, fibroblast growth factor 12 and CD4 were down-regulated on the different surfaces. The attachment and expression of key osteogenic regulatory genes were enhanced by the surface morphology of the dental materials used.