Optimization of the neck region of dental implants with a bioactive, resorbable coating.

With the goal of shortening the postoperative healing phase and the minimization of the risk of peri-implantitis around dental implants, a polymer coating, with improved surface biocompatibility in the region of soft tissue penetration by the implant, was investigated. The polymer used was the relatively slowly resorbable poly-beta-hydroxybuterate (PHB) whose surface was further activated in a NH3--plasma. The influence of surface roughness of the substrate (commercially pure titanium) as well as the influence of the edge radii on the test samples was determined in prior studies. These studies formed the basis for an optimised coating process. In-vitro biocompatibility was determined using a human gingival primary cell culture. Surface morphology was determined with SEM and AFM to complement the cell culture studies.

Dating and context of rock engravings in southern Africa.

Rock art is seldom recovered from sealed archeological contexts and is therefore difficult to date or integrate with other artifactual assemblages. South African engravings, found on low rocks at open-air sites, exemplify the problem. Multiscale spatial study of technique, thematic variation, faunal content, geoarcheological paterning, settlement history, and ethno-archeological setting provides coherent information on environment, time, and group identity. The major periods of naturalistic animal engravings coincide with wetter and warmer climates abot 3200 to 2500 and 2250 to 1800 years before present, but the earliest engravings may be older than 4000 years. Geometric designs were favored after 1300 years before present, when climate was drier and when one identity-conscious population of Bushman engravers first encountered domesticated animals.

Complications in acute pancreatitis.

In a group of 260 non-selected cases of acute or subacute pancreatitis, severe complications occurred in 60 (23.1%). Long lasting shock and/or massive internal bleeding (5.4%), severe renal problems (anuria, tubular necrosis, nephrosis) (5.4%) and frank hepatic failure due to extensive liver necrosis or other severe destruction (5.0%), invariably lead to death. The clinical group of findings pointing to a fatal course usually manifested themselves during the first three days. Severe renal and hepatic lesions were in many cases secondary to shock in fulminant rapidly deteriorating cases. Prevention and efficient management of shock are thus essential prerequisites for saving the patient. Other important complications included severe intra-abdominal suppuration and abscesses, peritonitis and sepsis (3.9%), pseudocysts of the pancreas (5.4%) and biliary stasis (18.4%). Severe obstruction to bile flow with associated jaundice occurred in only 4.6% of cases; unselected operative biliary decompression does not therefore appear indicated. If an early laparotomy is performed, efficient debridement and drainage are of utmost importance. Fatal pancreatitis was associated with extensive necrosis of the pancreas in about 80% of cases; possibly subtotal pancreatic resection at an early laparotomy would have given better results in these most severe cases, as recently reported in the literature.

The aetiology of acute pancreatitis.

The most common aetiological factors of acute pancreatitis in an unselected group of 215 consecutive surgical patients were biliary tract disease (40.0%), alcoholism (20.0%) and gastroduodenal ulcer (4.2%). In women, biliary tract disease was by far the most common cause (61.3%), but in men considerably high frequencies of alcoholism (48.3%) and gastroduodenal ulcer (15.7%) were noted as at least one possible aetiological factor. This deserves a special notation when contemplating prophylactic measures to prevent recurrences of acute pancreatitis.

The aetiology of acute pancreatitis.

The most common aetiological factors of acute pancreatitis in an unselected group of 215 consecutive surgical patients were biliary tract disease (40.0%), alcoholism (20.0%) and gastroduodenal ulcer (4.2%). In women, biliary tract disease was by far the most common cause (61.3%), but in men considerably high frequencies of alcoholism (48.3%) and gastroduodenal ulcer (15.7%) were noted as at least one possible aetiological factor. This deserves a special notation when contemplating prophylactic measures to prevent recurrences of acute pancreatitis.

Complications in acute pancreatitis.

In a group of 260 non-selected cases of acute or subacute pancreatitis, severe complications occurred in 60 (23.1%). Long lasting shock and/or massive internal bleeding (5.4%), severe renal problems (anuria, tubular necrosis, nephrosis) (5.4%) and frank hepatic failure due to extensive liver necrosis or other severe destruction (5.0%), invariably lead to death. The clinical group of findings pointing to a fatal course usually manifested themselves during the first three days. Severe renal and hepatic lesions were in many cases secondary to shock in fulminant rapidly deteriorating cases. Preventing and efficient management of shock are thus essential prerequisites for saving the patient. Other important complications included severe intra-abdominal suppuration and abscesses, peritonitis and sepsis (3.9%), pseudocysts of the pancreas (5.4%) and biliary statis (18.4%). Severe obstruction to bile flow with associated jaundice occurred in only 4.6% of cases; unselected operative biliary decompression does not therefore appear indicated. If an early laparotomy is performed, efficient debridement and drainage are of utmost importance. Fatal panreatitis was associated with extensive necrosis of the pancreas in about 80% of cases; possibly subtotal pancreatic resection at an early laparotomy would have given better results in these most severe cases, as recently reported in the literature.

Conservative surgery in acute pancreatitis.

During the years 1955-1970, 260 patients were treated for acute pancreatitis in the surgical department of the Maria Hospital. 62 of them were operated on, 44 electively, and 18 as emergency cases. The main conclusions from this series are as follows: 1) if laparotomy is required, efficient debridement and drainage are of great importance, 2) random operative decompression of the biliary duct system is statistically of little benefit, 3) in most cases purely conservative treatment or conservative surgery, taking into account individual conditions, gives good results, but obviously more radical measures are necessary for a favourable outcome in the most severe cases, as reported in the current literature, 4) in elective surgery it is important to postpone the curative operation by several weeks, preferably months, when possible, to avoid exacerbation or relapse of the disease.

Fatal pancreatitis. A clinical and post-mortem study on 24 cases of acute pancreatitis with fatal outcome, with special reference to some clinical aspects of autopsy findings.

During the years 1955-1970, 260 patients were treated in the surgical department of the Maria Hospital for acute pancreatitis. 24 of them died and went to autopsy. This study includes all these 24 patients.