Dimensional ridge alterations following immediate implant placement in molar extraction sites: a six-month prospective cohort study with surgical re-entry.

AIM: To assess dimensional ridge alterations following immediate implant placement in molar extraction sites. MATERIAL AND METHODS: Twelve subjects received 12 immediate transmucosal implants in molar extraction sites. Peri-implant defects were treated according to the principles of Guided Bone Regeneration by means of a deproteinized bone substitute and a bioresorbable collagen membrane. Changes in vertical (IS-BD, CREST-BD) and horizontal distances (EC-I, IC-I) of alveolar bony walls to the bottom of the defects (BD) and to the implant surfaces (I) were compared between implant placement and surgical re-entry at 6 months. RESULTS: The implant survival rate at 6 months was 100%. Statistically significant differences (P<0.01) were observed in the mean changes in vertical distances IS-BD and CREST-BD between baseline and re-entry. At re-entry, all peri-implant marginal defects assessed from the internal socket wall to the implant surface (IC-I) were healed. The residual combined thickness of the buccal wall with the newly formed peri-implant bone at sites with an initial thickness of 1 mm was statistically significantly smaller (P<0.05) compared with that of sites with an initial buccal thickness of 2 mm (2.50 +/- 0.76 vs. 4+/-0 mm). CONCLUSIONS: The marginal defects around immediate implants placed in molar extraction sites were completely filled after 6 months of healing through de novo bone formation. Bone resorption was observed from the external aspects of the buccal and oral socket walls. Dimensional changes of the external socket walls were mostly pronounced at the buccal aspects.

Soft tissues healing at immediate transmucosal implants placed into molar extraction sites with buccal self-contained dehiscences. A 12-month controlled clinical trial.

AIM: To assess soft tissues healing at immediate transmucosal implants placed into molar extraction sites with buccal self-contained dehiscences. MATERIAL AND METHODS: For this 12-month controlled clinical trial, 15 subjects received immediate transmucosal tapered-effect (TE) implants placed in molar extraction sockets displaying a buccal bone dehiscence (test sites) with a height and a width of > or =3 mm, respectively. Peri-implant marginal defects were treated according to the principles of Guided Bone Regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresorbable collagen membrane. Fifteen subjects received implants in healed molar sites (control sites) with intact buccal alveolar walls following tooth extraction. In total, 30 TE implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were used. Flaps were repositioned and sutured, allowing non-submerged, transmucosal soft tissues healing. At the 12-month follow-up, pocket probing depths (PPD) and clinical attachment levels (CAL) were compared between implants placed in the test and the control sites, respectively. RESULTS: All subjects completed the 12-month follow-up period. All implants healed uneventfully, yielding a survival rate of 100%. After 12 months, statistically significantly higher (P<0.05) PPD and CAL values were recorded around implants placed in the test sites compared with those placed in the control sites. CONCLUSIONS: The findings of this controlled clinical trial showed that healing following immediate transmucosal implant installation in molar extraction sites with wide and shallow buccal dehiscences yielded less favorable outcomes compared with those of implants placed in healed sites, and resulted in lack of 'complete' osseointegration.

Immediate transmucosal implant placement in molar extraction sites: a 12-month prospective multicenter cohort study.

AIM: To assess the clinical and radiographic outcomes of immediate transmucosal placement of implants into molar extraction sockets. STUDY DESIGN: Twelve-month multicenter prospective cohort study. MATERIAL AND METHODS: Following molar extraction, tapered implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were immediately placed into the sockets. Molars with evidence of acute periapical pathology were excluded. After implant placement and achievement of primary stability, flaps were repositioned and sutured allowing a non-submerged, transmucosal healing. Peri-implant marginal defects were treated according to the principles of guided bone regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresrobable collagen membrane. Standardized radiographs were obtained at baseline and 12 months thereafter. Changes in depth and width of the distance from the implant shoulder (IS) and from the alveolar crest (AC) to the bottom of the defect (BD) were assessed. RESULTS: Eighty-two patients (42 males and 40 females) were enrolled and followed for 12 months. They contributed with 82 tapered implants. Extraction sites displayed sufficient residual bone volume to allow primary stability of all implants. Sixty-four percent of the implants were placed in the areas of 36 and 46. GBR was used in conjunction with the placement of all implants. No post-surgical complications were observed. All implants healed uneventfully yielding a survival rate of 100% and healthy soft tissue conditions after 12 months. Radiographically, statistically significant changes (P<0.0001) in mesial and distal crestal bone levels were observed from baseline to the 12-month follow-up. CONCLUSIONS: The findings of this 12-month prospective cohort study showed that immediate transmucosal implant placement represented a predictable treatment option for the replacement of mandibular and maxillary molars lost due to reasons other than periodontitis including vertical root fractures, endodontic failures and caries.

Guided tissue regeneration versus coronally repositioned flap in the treatment of recession with double papillae.

Twenty buccogingival recessions (3 mm deep) in twenty patients were selected and divided into two groups. Periodontal parameters were recorded (recession reduction, probing depth, clinical attachment level, and keratinized tissue width), and both groups were treated with regenerative therapy using a resorbable polylactic acid membrane. The test group was treated using the double papilla flap procedure, and the control group was treated using the coronally repositioned flap procedure. The results obtained at a 1-year follow-up were comparable between the test and control groups for recession reduction, probing depth, and clinical attachment level, although the test group obtained a very large amount of keratinized gingiva (+74.7%) compared to the control group.

[Carcinoma of the pancreatic body and tail]. / Il carcinoma del corpo-coda pancreatico.

Carcinoma of the body and tail of the pancreas still remains the disease form with the worst prognosis and evolution. In spite of a huge improvement in diagnostic methods, anaesthetic and surgical procedures and pre- and postoperative assistance, the results in terms of early diagnosis and long-term survival have been generally disappointing. The authors describe their own experience regarding three such tumours treated in five years, analysing the literature data, and referring to the current guidelines in diagnostics and surgical therapy. They then go on to propose a step-by-step approach to the management of these patients. The difficulty of obtaining an early diagnosis of the disease which derives from many factors, such as unspecific and late appearing symptoms, is stressed. They conclude by confirming the need to perform a radical resection, if possible, which, together with a combination of radio- and chemotherapy, is the only procedure capable of holding out some hope of a cure.

[Torsion of the greater omentum as a rare cause of acute abdomen]. / La torsione del grande epiploon quale rara causa di addome acuto.

Taking as their starting point a case of greater omental torsion recently observed in their surgical department, the authors carefully review the topic and the relevant literature data. This is a rare condition, which though presenting diagnostic difficulties which make it hard to identify preoperatively, poses no problems of a therapeutic nature.

[Environmental pathology and dentistry. III. Carcinogenic process of the soft tissues of the oral cavity]. / Patologia ambientale ed odontoiatria. Nota III. I processi cancerosi dei tessuti mobili della cavità orale.

The context in which a relationship between environmental pathologies and dentistry is most easily distinguished is with reference to the carcinogenic processes of soft tissues in the oral cavity. In this study, a distinction is made between potentially cancerous lesions and true carcinomas, and the relationship between tumour pathology of the oral cavity and the surrounding environment is analysed. Clinical aspects are also illustrated.

[The role of Langerhans cells in periodontal disease]. / Il ruolo delle cellule del Langerhans nella malattia parodontale.

Following a morphological description of Langerhans cells, the paper analyses their functional activity both as phagocytic cells and as antigen-presenting cells. The role of this cell population in periodontal disease is the examined in the light of recently reported findings.

[The role of phagocytic cells in periodontal disease]. / Il ruolo delle cellule fagocitarie nella malattia parodontale.

Having described the morphological and functional characteristics of phagocytic cells, the paper underlines that, in addition to the etiological responsibility of bacterial plaque, the main role in the onset and evolution of periodontitis is played by the host's response. Phagocytic response plays a fundamental role in the host's defence reaction and represents the first barrier to the penetration of bacteria into periodontal tissue. In addition to their defensive role, phagocytic cells may also be responsible for damage to periodontal tissue as a collateral effect of their phagocytic function, thus worsening the periodontal lesion.

[The direct and indirect tissue-damaging action of periodontally pathogenic bacteria]. / L'azione istolesiva diretta ed indiretta dei batteri parodontopatogeni.

The paper describes the aggregation mechanism of bacterial plaque to the acquired film and analyses the method with which bacteria adheres to periodontal tissues, before examining the direct and indirect histolesive capacity of periodontopathogenic bacteria.

[The role of LGL cells (NK and K) in periodontal disease]. / Il ruolo delle cellule "LGL" (NK e K) nella malattia parodontale.

The paper reports the morphological and functional aspects of NK and K cells in the light of the most recent advances in the field, and pays particular attention to their cytotoxic and suppressor capacities. The role of NK and K cells in periodontal disease is then described and it is observed how this cell population is absent in healthy gums, whereas it is found with increasing frequency at disease reaches the chronic stage. The presence of LGL cells is therefore thought to be associated with the development of plaque-induced inflammation.

[Solitary perforated diverticulum of the cecum: a case report]. / Il diverticolo perforato del cieco: contributo clinico.

The Authors report a case of acute abdomen caused by a perforated solitary diverticulum of the cecum recently treated. This is a rare disease that usually is diagnosed, in the surgical theatre because it is a topic of emergency surgery. From Literature analysis it is obvious that a correct preoperative diagnosis is difficult to make because of the large number of possible abdominal pathologies with similar symptoms. Also the therapeutic approach is so extremely variable that the operation could range from a simple conservative type to right hemicolectomy. A proper approach will be conservative with a simple diverticulectomy when the inflammatory reaction is localized in the colonic wall while a right colectomy could be performed when the inflammatory reaction is more advanced or a large mass suggestive of a carcinoma is present.

[Primary carcinoma of the gastric stump. Physiopathological, diagnostic and therapeutic considerations]. / Il carcinoma primitivo del moncone gastrico. Considerazioni fisiopatologiche, diagnostiche e terapeutiche.

Even though the primary carcinoma of the gastric stump is a tumor that will diminish in frequency in the years to come, it is still a topic of scientific studies. The authors report their experience with four cases of primary carcinoma of the gastric stump treated surgically as compared to 89 cases of carcinoma of the stomach operated in the same period. After some comments on the etiopathogenesis that is at the basis of the neoplastic mutations of the remaining gastric epithelium, clinical, prognostic and pathologic features that differentiate this type of tumor from those which develop in unoperated stomachs are examined and, then, the most frequent therapeutic approaches are illustrated. In conclusion, it is sustained that patients who have undergone partial gastrectomy for benign disease should be closely followed-up from the tenth year after the operation and, in any case, in those who are over fifty years of age.

Bioassay for thymic extracts: guinea pig spleen lymphocytes-rabbit red blood cells rosette method.

An assay is described for assessing the potency of thymic extracts by the capacity of guinea pig spleen lymphocytes to form rosettes with rabbit red blood cells. Its sensitivity and reproducibility have been evaluated by statistical analysis of the data obtained testing different batches of the calf thymus extract TP-1.

Enhancement of the immunocompetence in neonatal guinea pigs by a thymic factor (TS).

The immunocompetence of newborn guinea pigs was evaluated in comparison with that of adults. The capacity of spleen cells from neonatal guinea pigs to produce antibodies to SRBC was found to be reduced, while no differences were observed in the capacity of those cells to respond to mitogenic stimulation or to form E rosettes with rabbit red blood cells. The in vivo treatment of newborn animals with a thymic factor (TS) induced an increase in the number of antibody-producing cells and an increase in the response to mitogenic stimulation but no variation in the number of rosette-forming cells. The effect of TS on both responses to SRBC and to mitogenic stimulation, was dose dependent.

Impaired T-cell functions in aged guinea-pigs restored by thymostimulin (TS).

The age-related changes of different T-cell activities in guinea pigs and the effect of Thymostimulin (TS), a thymus extract, on the immunocompetence of these cells was studied. Mitogen-induced proliferation of peripheral blood lymphocytes was increased by TS in vitro. The intraperitoneal administration of TS (5 mg/kg) to aged animals restored the helper function of T lymphocytes and enhanced the reactivity to mitogens of both peripheral blood lymphocytes and spleen lymphocytes. The data obtained suggest that as in other species, there is an age-associated decline of immunological response, in guinea pigs too, probably due to a deficiency of thymic hormone(s) and that TS could correct this deficiency.

Maintenance of implants: an in vitro study of titanium implant surface modifications subsequent to the application of different prophylaxis procedures.

The aim of the present study was to evaluate surface alterations on titanium implant necks subsequent to different prophylaxis procedures. Fifty ITI implants were utilized. Forty implants were treated with 10 different prophylaxis procedures (ultrasonic scaler, plastic tip ultrasonic scaler, stainless steel curette, titanium curette, teflon curette, air powered system, abrasive rubber cups, polishing rubber cup and brush), and 10 implants were left as untreated controls. Surface alterations were studied on an area of 1 mm x 0.9 mm and quantified using optical microscopic, SEM and laser prophylometer analysis. The use of laser prophylometer provided an objective criterion for evaluation, expressing implant neck surface alterations in numeric values in terms of two roughness indexes, Ra and Rz. The results showed that, in comparison with the controls (Ra = 0.50; Rz = 3.98) the procedures investigated could be divided into 3 main groups: 1) Methods which altered the implant neck surface producing increased roughness (Ra = 0.68-2.08; Rz = 4.68-11.92); 2) Methods which left the implant neck surface unaltered (Ra = 0.44-0.57; Rz = 0.42-3.46); 3) Methods resulting in a smoothening of the implant neck surface (Ra = 0.36; Rz = 2.15). Group 1 included procedures that should be avoided. However, it appeared safe to apply the procedures of groups 2 and 3. To confirm these results, it will be necessary to evaluate the plaque- and calculus-removing efficacy from titanium neck implant surfaces in vivo.

Ditazole activity and its interaction with urokinase on experimental thrombosis.

The effect of ditazole, a new antiaggregant oxazole derivative as well as its possible interaction with urokinase on the formation of electrically induced thrombus, was assayed in rabbits. The activity of ditazole in reducing thrombus weight was comparable to that of aspirin. In the ditazole- or aspirin-treated animals, the microscopical examination of the thrombus showed a reduction in the fibrin component, and well-isolated platelets not undergoing a viscous metamorphosis were present. Urokinase, administered in combination with these antiaggregant drugs, did not induce a further reduction in thrombus weight. However, this additional treatment did induce clearly visible lytic areas and histological modifications as observed with the antiaggregant drugs. These data suggest that the antiplatelet drug ditazole may be an effective antithrombotic agent in man and could facilitate the penetration of urokinase into the thrombus.