The SLA (sandblasted with large grit and acid etched) surface is a textured surface that has been documented to lead to a rapid and strong implant fixation. The purpose of the present study was to determine the contribution of sandblasting in addition to etching to implant anchorage. It was also aimed to determine if the pits carved during etching alone have a bone-interlocking capacity that leads to microanchorage between the implant and bone. SLA implants and machined-and-acid-etched (MA) implants were placed in the maxilla of Land Race pigs. After 10 weeks of healing, they were reverse torqued. The reverse torque of the SLA and MA implants was 157.29 +/- 38.04 N cm and 105.33 +/- 25.12 N cm, respectively. Sandblasting increased bone anchorage by 49.3%; the difference was statistically significant (p =.028). Bone was found attached to both surfaces; bone ingrowth was found in the pits of both surfaces. It is suggested that the two surfaces are able to generate bone interlocking and mechanical coupling at the interface. When finite-element modeling is performed with these surfaces, it is suggested that the bound mode be used instead of the slip mode.

The aim of this study was to test the effectiveness of isosorbide-5-mononitrate (IM) as an adjunct to propranolol (PR) in the prevention of variceal rebleeding. Ninety-five cirrhotic patients with variceal bleeding were randomly assigned to treatment with PR ؉ IM (46 patients) or PR alone (49 patients). Eighteen patients in the PR ؉ IM group and 28 in the PR group had rebleeding during the 2 years after randomization. The actuarial probability of rebleeding 2 years after randomization was lower in the PR ؉ IM group (40.4% vs. 57.4%) but the difference was not significant (P ‫؍‬ .09). However, the decrease in the risk of rebleeding reached statistical significance after stratification according to age, i.e. less than 50 versus H50 years old, (P ‫؍‬ After the initial control of a hemorrhage due to rupture of gastric or esophageal varices, patients are at high risk of experiencing further bleeding and death. 1-3 Therapy to prevent rebleeding from esophageal varices in patients with cirrhosis is essential. Propranolol (PR), a nonselective betaadrenergic blocker, is widely used for this purpose. PR decreases portal pressure. This portal-hypotensive effect is mediated by a reduction of blood inflow into the portocollateral circulation. 4,5 Meta-analyses of data from controlled trials have confirmed that rates of rebleeding are decreased by approximately 40% and overall survival is improved by approximately 20% by PR. 6,7 However, on the basis of the hemodynamic response observed in patients, 2 problems related to PR administration still persist: first, the existence of a group of nonresponders, regardless of the administered dose; and second, the variable reduction of portal pressure seen in responders. 8,9 One possible reason for inefficacy of beta-blockers is a concomitant increase in portocollateral resistance that counteracts the hypotensive effects of decreasing blood flow through the portocollateral circulation. 10

The titanium surface obtained by sandblasting and etching (SLA) is an easily alterable surface that smears and loose its typical texture. In addition, the etching process modifies the surface composition of commercially pure titanium; the latter contains titanium and an added 20-40% of titanium hydride. Therefore, the influence of a heavy surface alteration and the influence of the composition at the SLA surface, i.e. with and without titanium hydride, were investigated in vivo. Three implant groups were inserted in the mandible of Land Race pigs and left to heal during 10 weeks in a submerged way: (1). a standard SLA control group (SLAstd) with the SLA surface containing titanium hydride; (2). a test group with the SLA surface heavily altered at the thread level (SLAalt); (3). a test group with an SLA surface devoid of titanium hydride (SLAT). Sample size was n = 8. Histomorphometry analysis did not show a statistically significant difference between the control group (SLAstd: 82.12 + 6.1%), the altered surface test group (SLAalt: 86.25 + 7.4%) and the SLA without titanium hydride test group (SLAT: 75.12 + 7.6%). The data suggest that alteration of the SLA surface, if it occurs, should not be detrimental to bone response. The soft and easy smearable SLA surface might even be an advantage when surface maintenance is required. Surface composition did not play a significant role in the bone response to the SLA surface and it can therefore be concluded that the osteophilic properties of the SLA surface are due to its surface topography and not to its specific surface composition.