Changes in inflammatory mediators in peri-implant fluid after implant insertion.

Background: Endosseous dental titanium implants have revolutionized restorative dentistry and have made a significant impact on improved patient care. The aim of this study was to compare and evaluate the influence of the placement technique on periodontal health.

Methods: A baseline examination was performed in patients with submerged and non-submerged titanium implants, including an evaluation of plaque index (PI), gingival index (GI), periodontal probing depth (PD), clinical attachment level (CAL), and bone level, as well as histamine and arachidonic acid metabolite concentrations, in the peri-implant crevicular fluid.

Salivary histamine level as a predictor of periodontal disease in type 2 diabetic and non-diabetic subjects.

Background: Some previous investigations underscored the role of histamine in periodontal disease, especially in diabetic patients, but the behavior of this inflammatory mediator in the early phases of periodontal involvement remains unclear. The aim of the present study was to correlate the presence of histamine in saliva with clinical parameters in healthy, periodontitis-affected, and diabetic subjects to ascertain whether this amine may serve as a predictive index of periodontal risk.

Methods: For this purpose, subjects were selected as follows: 1) with newly diagnosed type 2 diabetes mellitus; 2) with neither diabetes nor periodontitis; 3) with no diabetes but with chronic, untreated periodontal disease.

PIXE micro-beam mapping of metals in human peri-implant tissues.

Previous investigations did not agree about the possible presence of titanium and other metals in the tissues around endosteal dental implants and joint prostheses. Indeed, while some authors reported diffusion of metals into the tissues, some others did not find evidence of this phenomenon. In the present study, four dental titanium implants, removed with the surrounding tissues from patients at various time intervals after the insertion, were studied by means of the micro-beam proton-induced X-ray emission (PIXE micro-beam) technique, which draws maps showing the tissue distribution of elements with a detection limit of about 1 ppm.

Plain and drug loaded polyphosphazene membranes and microspheres in the treatment of rabbit bone defects.

The healing of periodontal surgical defects was studied in rabbits, using polyphosphazenes (POP) membranes and microspheres, both plain or drug-enriched. POP polymers having amino acid ester as backbone substituents, are used since they resorb and undergo hydrolytic degradation to ammonia, phosphate and amino acids. Fourteen animal were operated in tibia, and other fourteen at angle of the mandible, that was reached by extraoral access.

Polyamines in nickel-titanium archwire-induced gingivitis in adolescents.

Background: Polyamines spermine, spermidine, and putrescine are involved in a number of inflammatory diseases, but their role in the development of gingivitis and periodontitis has not been fully investigated. The goal of this investigation was to study the levels and the variations of these amines, and the main enzymes related to their metabolism, during archwire orthodontic treatment, a condition which may induce gingivitis.

Methods: Sixty patients (age range: 11 to 27 years) were examined for gingivitis occurring during nickel-titanium (Ni-Ti) archwire orthodontic treatment.

In vitro buffering properties of 3 composite resins.

Aim: A dental composite resin, Ariston pHc, has been described as having a cariostatic effect by buffering acid saliva and preventing decalcification and infiltration of restorations. The buffering effect has been reported due to the release of OH- originated from the alkaline glass embedded in the resin. The release would occur only in the presence of low salivary pH values.

Synthetic bone grafts in peri-implant bone dehiscences: histological results in humans.

This study describes the histological results found in three patients treated with osseointegrated implants and Bioplant HTR (Hard Tissue Replacement) synthetic bone graft in peri-implant dehiscences adjacent to implants. This therapy was carried out without the use of barrier membranes. Bioplant HTR is reported to act as its own barrier and prevent gingival soft tissue migration ingrowth.

Polyphosphazene membranes and microspheres in periodontal diseases and implant surgery.

Membranes or microcapsules made from polyphosphazenes bearing amino acid side groups are proposed for the treatment of periodontal diseases. Polyphosphazene membranes, prepared with alanine ethyl ester and imidazole in the molar ratio of 80:20 as phosphorus substituents, gave a degradation rate that corresponded to the healing of the bone defect. These membranes were much more successful in promoting healing of rabbit tibia defects than polytetrafluoroethylene membranes.

Histochemical and confocal laser scanning microscopy study of the bone-titanium interface: an experimental study in rabbits.

The aim of our study was an analysis of the presence of an unmineralized bone matrix between mineralized bone and titanium screws in rabbit tibiae. A microscopical analysis, using a histochemical technique, was performed on the titanium-bone interface of commercially pure titanium implants placed in rabbit tibiae and harvested after 2 months. Thin ground sections of the specimens were prepared by the cutting-grinding system and stained using the von Kossa method for calcium salts and basic fuchsin for osteoid.

Light and confocal laser scanning microscopic evaluation of hydroxyapatite resorption patterns in medullary and cortical bone.

An animal study was conducted with unloaded blocks and hydroxyapatite (HA)-coated titanium implants. Four HA blocks were positioned in rabbit tibiae and four HA-coated titanium implants were positioned in pig tibiae. Implants were positioned so that half was placed in cortical bone and half in medullary space.

Resistance to fracture of ceramic jacket crowns.

The resistance to fracture of jacket crowns, fabricated of cast glass-ceramic and five traditional ceramics, was evaluated. Four identical jacket crowns of each type were constructed on absolutely equal dental abutments in epoxy resin, obtained from a primary mandibular molar. An increasing load was then applied to the mesiobuccal cusp of each of the 24 crowns.

The influence of environmental pressure on retentiveness of prosthetic crowns: an experimental study.

To determine the effect of pressure variations on the retention of prosthetic crowns, 36 identical, cast metal crowns were fixed to simulated, epoxy resin crown preparations with zinc oxyphosphate cement. Eighteen specimens were placed in a hyperbaric chamber and subjected to 15 cycles of simulated immersion at 30 m and decompression, as usually carried out by scuba divers. The untreated specimens served as controls.

Ultrastructural findings on the interface between hydroxylapatite and oral tissues.

Two patients were treated with surgical implantation of synthetic, granular, nonporous hydroxylapatite to correct bone defects around dental implants. Ultrastructural examination of biopsy specimens taken several months later showed that the hydroxylapatite material was encapsulated mostly by fibrous connective tissue, without any signs of active inflammation. Osteoid and mature bone were also present in many areas.

[Water absorption and resistance to wear of 2 newly invented composite resins].

Two recently built composites, one for posterior teeth, and the other for general employ, were evaluated in relation to their water absorption and resistance to wear by means of the "scratch test". Critical loads and attrition of the two materials were also evaluated, with statistical analysis. The results supported the good qualities of the two composites, which are to be considered very advanced in the field of esthetic reconstruction materials.

[Taste changes in diabetics. Clinico-experimental study].

A preliminary research was carried out, comparing taste sensitivity of 33 healthy subjects and 120 diabetics patients, either with complications or not. After this, a further analysis of the results was done, collecting the patients into more numerous groups. A significant decrease of the sensitivity for some tastes in some oral areas was attested, as regards diabetics with vascular and neurologic complications.

[Intracoronal tooth fixation with metal and composite wire: longitudinal study].

Dental splints with wire and composite resin: longitudinal controls. 126 intracoronal dental splints with wire and composite were performed in nearly ten years. Clinical results were good enough, because less than 20% of patients needed further cares.

[Taste sensitivity in diabetic patients].

Taste sensitivity of 33 healthy subjects and 120 diabetic patients, either suffering from complication or not, was compared. Diabetic patients showed statistically significative reduction of sensitiveness for some tastes in some oral zones. Taste decrease looks to be related more to vascular of diabetes, than to neurologic ones.