Comparison between Erich arch bars and intermaxillary screws in maxillofacial fractures involving the dental occlusion: a meta-analysis.

This systematic review aimed to compare the Erich arch bars (EABs) with intermaxillary fixation (IMF) screws in maxillofacial fractures involving dental occlusion on perioperative parameters. Four electronic databases were searched: MedLine (Pubmed), Web of Science, VHL, and Cochrane Library. Inclusion criteria comprised clinical trials comparing the two IMF methods, assessing at least one of the outcomes: occlusal stability, oral hygiene, quality of life, time to apply and remove IMF appliances, and complications. Risk of bias was evaluated through the Cochrane risk of bias tool. Fifteen papers were included in the qualitative analysis and 12 of those in the meta-analysis. Times for EABs application (mean difference (MD) 46.83; 95% confidence interval (CI): 30.63-63.02) and removal (MD 22.89; 95% CI 14.61-31.17) were longer compared with IMF screws. There is higher risk of glove perforation (risk ratio (RR) 3.81; 95% CI 2.41-6.04) and lower risk of iatrogenic injuries (RR 0.21; 95% CI 0.09-0.48) when placing EABs compared with IMF screws. No significant differences in plaque index were found (MD 1.07; 95% CI -0.17 to 2.31). The quality of this evidence ranged from very low to low and was mainly compromised by risk of bias assessment. Further studies are necessary to evaluate transurgical IMF stability and postoperative occlusal quality and quality of life when comparing EABs with IMF screws.

One Hundred Consecutive Liver Transplants Using Institutes Georges Lopez-1 Preservation Solution: Outcomes and Prognostic Factors.

BACKGROUND: There are only 4 prior studies reporting on outcomes of liver transplantation (LT) using Institutes Georges Lopez-1 (IGL-1) preservation solution. Detection of negative predictors of LT using IGL-1 may help finding strategies to protect selected recipients at higher risk of graft failure and death. METHODS: Review of all consecutive adult patients who underwent a first whole-graft LT using IGL-1 at authors' institution from 2013 to 2016. Primary end point was graft failure within the first 90 postoperative days (PODs). Graft losses due to any cause (including all deaths with a functioning graft) were recorded as graft failures. RESULTS: Of all 100 patients included in this study, 37 were women; median age was 58 years (range 18-71). There were 12 graft losses during the first 90 PODs (including 3 cases of primary nonfunction of the liver allograft), and 10 of the 12 graft losses occurred on first 30 PODs. All 12 patients who experienced graft loss (including 1 patient who underwent liver retransplantation) died within the first 90 PODs. Of the total 100 patients, 14 experienced biliary complications. Univariate analysis revealed prolonged warm ischemic time (WIT) as the only predictor of 90-day graft failure (odds ratio = 23.5, confidence interval = 1.29-430.18, P = .03). The cutoff by receiver operating characteristic curve for WIT was 38 minutes (area under the curve = 0.70). Positive predictive value for WIT >38 minutes was 94.3%. CONCLUSIONS: LT using IGL-1 can be performed safely. Similar to prior reports on LT using other preservation solutions, prolonged WIT was associated with adverse outcomes.

Effect of tamoxifen on the coronary vascular reactivity of spontaneously hypertensive female rats.

Tamoxifen has been associated with a reduction in the incidence of myocardial infarction. However, the effects of tamoxifen on coronary reactivity have not been fully elucidated. The objective of this study was to determine the effects of chronic treatment with tamoxifen on coronary vascular reactivity in spontaneously hypertensive rats (SHR). Female SHR were divided into four groups (N = 7 each): sham-operated (SHAM), sham-operated and treated with tamoxifen (10 mg/kg) by gavage for 90 days (TAMOX), ovariectomized (OVX), and ovariectomized and treated with tamoxifen (OVX+TAMOX). Mean arterial pressure (MAP), heart rate (HR), coronary perfusion pressure (CPP), and coronary vascular reactivity were measured. MAP and HR were reduced (9.42 and 11.67%, respectively) in the OVX+TAMOX group compared to the OVX group (P < 0.01). The coronary vascular reactivity of the OVX+TAMOX group presented smaller vasoconstrictor responses to acetylcholine (2-64 µg) when compared to the OVX group (P < 0.01) and this response was similar to that of the SHAM group. The adenosine-induced vasodilator response was greater in the TAMOX group compared to the SHAM and OVX groups (P < 0.05). Baseline CPP was higher in OVX+TAMOX and TAMOX groups (136 ± 3.6 and 130 ± 1.5 mmHg) than in OVX and SHAM groups (96 ± 2 and 119 ± 2.3 mmHg; P < 0.01). Tamoxifen, when combined with OVX, attenuated the vasoconstriction induced by acetylcholine and increased the adenosine-induced vasodilatory response, as well as reducing the MAP, suggesting beneficial effects of tamoxifen therapy on coronary vascular reactivity after menopause.

Effect of tamoxifen on the coronary vascular reactivity of spontaneously hypertensive female rats

Tamoxifen has been associated with a reduction in the incidence of myocardial infarction. However, the effects of tamoxifen on coronary reactivity have not been fully elucidated. The objective of this study was to determine the effects of chronic treatment with tamoxifen on coronary vascular reactivity in spontaneously hypertensive rats (SHR). Female SHR were divided into four groups (N = 7 each): sham-operated (SHAM), sham-operated and treated with tamoxifen (10 mg/kg) by gavage for 90 days (TAMOX), ovariectomized (OVX), and ovariectomized and treated with tamoxifen (OVX+TAMOX). Mean arterial pressure (MAP), heart rate (HR), coronary perfusion pressure (CPP), and coronary vascular reactivity were measured. MAP and HR were reduced (9.42 and 11.67 percent, respectively) in the OVX+TAMOX group compared to the OVX group (P < 0.01). The coronary vascular reactivity of the OVX+TAMOX group presented smaller vasoconstrictor responses to acetylcholine (2-64 µg) when compared to the OVX group (P < 0.01) and this response was similar to that of the SHAM group. The adenosine-induced vasodilator response was greater in the TAMOX group compared to the SHAM and OVX groups (P < 0.05). Baseline CPP was higher in OVX+TAMOX and TAMOX groups (136 ± 3.6 and 130 ± 1.5 mmHg) than in OVX and SHAM groups (96 ± 2 and 119 ± 2.3 mmHg; P < 0.01). Tamoxifen, when combined with OVX, attenuated the vasoconstriction induced by acetylcholine and increased the adenosine-induced vasodilatory response, as well as reducing the MAP, suggesting beneficial effects of tamoxifen therapy on coronary vascular reactivity after menopause.

Follow up after LLETZ: could schedules be modified according to risk of recurrence?

OBJECTIVES: To document the pattern of recurrence of disease following large loop excision of the transformation zone (LLETZ) to identify a low risk group of women who might benefit from less intensive cytological surveillance. DESIGN: Analysis of prospectively collected information with retrospective review of follow up smears. POPULATION: Three thousand, five hundred and sixty women who underwent LLETZ (median age 31 years; IQR 12 years). SETTING: Colposcopy clinic at Northern Gynaecological Oncology Centre, Gateshead. METHODS: Women treated with LLETZ from 1988 to 1995 were reviewed. Information on the pathology from LLETZ was collected prospectively and information on the subsequent smears was obtained from the family health authorities. RESULTS: Invasive cancer was detected on the original LLETZ in 134 women who were excluded from the study. Of the remaining 3,426 women, histology of LLETZ showed high grade CIN (II and III) in 2,371 (69%). At least one follow up smear was undertaken in 3,385 women (99%). This constituted 9,765 women years of follow up with a mean duration of 35 months. Four hundred and seventeen women (12.2%) had a dyskaryotic follow up smear. Incomplete excision of the lesion and an age of > or = 50 years at the time of the LLETZ were associated with an increased risk of recurrent CIN. Based on these risk factors the study group was divided into three risk groups: 1. women aged < 50 with no disease at the margins (n = 1680); 2. women aged > or = 50 with disease at the margins (n = 93); and 3. women aged < 50 with positive margins, or aged > or = 50 with negative margins (n = 1653). The cumulative survival without recurrent CIN at five years for these groups were 92%, 57% and 86%, respectively. CONCLUSION: Women aged > or = 50 with CIN at the margins of excision constituted a small minority high risk group (3%). Consideration should be given to repeat treatment of these women rather than surveillance. Women aged < 50 with complete excision of low grade CIN comprised 51% of the study group. These women were at low risk of recurrent CIN and might benefit from less intensive cytological surveillance following LLETZ.

Microstructure, toughness and flexural strength of self-reinforced silicon nitride ceramics doped with yttrium oxide and ytterbium oxide.

Self-reinforced silicon nitride ceramics with additions of either yttrium oxide or ytterbium oxide have been investigated at room temperature after various processing heat treatments. Devitrification of the intergranular phase in these materials is very sensitive to the heat treatment used during processing and does not necessarily improve their strength and toughness. Hot-pressed ceramics without a subsequent devitrification heat treatment were the strongest. The ytterbium oxide-doped silicon nitride ceramics were consistently tougher, but less strong, than the yttrium oxide-doped silicon nitride ceramics. In all the ceramics examined, the fracture toughness showed evidence for R-curve behaviour. This was most significant in pressureless sintered ytterbium oxide-doped silicon nitride ceramics. A number of toughening mechanisms, including crack deflection, bridging, and fibre-like grain pull-out, were observed during microstructural analysis of the ceramics. In common with other silicon nitride-based ceramics, thin amorphous films were found at the grain boundaries in each of the ceramics examined. Arrays of dislocations left in the elongated silicon nitride grains after processing were found to belong to the {101;0}<0001> primary slip system.

Porosity control of hydroxyapatite implants.

Conformation of hydroxyapatite (HAp) bodies was carried out using a multiple slip-casting technique, in order to obtain dual-layer samples with differential sized porosities. The external layer, because of its porosity, controlled by the addition of organic compounds (polyvinyl polyacrylate, PVC), will promote bone ingrowth. The internal denser layer, due to the addition of lithium phosphate (Li3PO4) as sintering additive, will give mechanical resistance to the implant. HAp aqueous suspensions were characterized by rheological measurements. Scanning electron microscopy (SEM) and intrusion mercury porosimetry (MP) were used to characterize sintered bodies. It can be concluded that it is possible to introduce gross porosity in HAp bodies by the addition of organic compounds. The results show that a compatible shrinking of the layers during the sintering process and a good frequency of pores with an appropriate size in the external layer can be achieved with the use of organic additives.

Morphological field emission-SEM study of the effect of six phosphoric acid etching agents on human dentin.

OBJECTIVES: This study evaluated the effects of six phosphoric acid-etching agents on dentin, the independent variables being two acid concentrations (10% and 32%-37%) and three thickener conditions (no thickener, silica, and polymer). The tested hypothesis was that the use of different etchants with similar concentrations of phosphoric acid would result in similar depths of dentin demineralization. METHODS: Thirty dentin disks were obtained from extracted human teeth by microtome sectioning. The dentin surfaces were etched with one of the etching agents, fixed, dehydrated and dried. The specimens were observed using a FE-SEM. The mean deepest demineralization of intertubular dentin was measured from fracture surfaces of the disks. These values were analyzed by ANOVA and Duncan's Test. The morphological appearance of the dentin surfaces was compared using the following observation criteria: 1) Presence of a cuff of peritubular dentin; 2) Relative thickness of the layer containing residual collagen or smear layer particles; and 3) Formation of a submicron hiatus at the bottom of the exposed collagen network. The pH of each of the etching agents was measured. A correlation analysis was made of the pH vs. the depth of dentin demineralization. RESULTS: Silica-thickened etchants did not demineralize dentin as deeply as did polymer-thickened etchants and unthickened etchants. High magnifications revealed three distinct zones within the demineralized dentin layer; an upper porous zone of residual smear layer or denatured collagen and residual silica particles (in groups etched with silica-thickened etchants), an intermediate area with randomly oriented collagen fibers, and a lower zone with submicron hiatus, few collagen fibers, and scattered hydroxyapatite inclusions. This hiatus was observable in all the specimens etched with the polymer-thickened etchants, in 90% of the specimens etched with the unthickened phosphoric acid liquids, and in 60% of the specimens etched with the silica-thickened gels. SIGNIFICANCE: The results obtained suggest that similar concentrations of phosphoric acid etchants containing distinct thickeners result in different demineralization depths as well as different morphology of etched dentin.