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Biomedical subjects

K Arvidson

Publications and source records attributed to K Arvidson.

47 records · Page 3Linked to original sources
PubMed1977

Galvanic series of some dental alloys.

Galvanic series for different metals in different electrolytes have been published, but never for dental alloys in artificial saline solution. The material classes studied are amalgam, gold alloy, nickel alloy, chromium cobalt casting alloy and temporary crown form. The electrogalvanic potentials were measured and determined in reference to a hydrogen electrode (H2/H+) arbitrarily defined as zero. A galvanic series of the tested materials was arranged in order of their potentials.

Chromium Alloys↗
PubMedDate not supplied

In vitro and in vivo experimental studies on single crystal sapphire dental implants.

Successful attachment of the oral tissues to an endosseous dental implant relies in part on its chemical stability, nontoxic properties and maintenance of normal cell functions in the surrounding tissues. The aim of this study was therefore to investigate these 3 factors experimentally. The corrosion resistance of single crystal sapphire (alpha-Al2O3) implants was analysed with respect to the release of aluminium ions; no ions could be detected in the test solutions. The influence of single crystal sapphire on the behaviour of human epithelial cells and fibroblasts derived from biopsies of the oral mucosa, was studied. The cells were cultured in chemically defined or in low serum-containing media. Compared to the corresponding control cultures, no effects on cell morphology and growth characteristics were observed. Sapphire rods were inserted subcutaneously into rats and tissue responses were examined after 4, 8 and 12 weeks post-implantation. None or slight reactions were found in the tissues. The combined evaluation of these experimental approaches indicates that single crystal sapphire is a material well suited for biological implantation.

Aluminum Oxide↗
PubMedDate not supplied

Scanning electron microscopy of fungiform papillae on the tongue of man and monkey.

The surface topography of the fungiform papillae of homo and monkey was studied by scanning electron microscopy. Different methods of specimen preparation were tried. Satisfactory preservation was obtained with fixation in formaldehyde, or in glutaraldehyde with postfixation in OSO4, followed by critical point drying. Taste pores were found in nearly half of the fungiform papillae. Up to 3 pores, located in the dorsal surface, were observed in a single papilla. Most taste pores opened in the form of a rounded crater with a diameter of about 5-7 mum, elevated slightly above the surface of the papilla. Microvilli could be observed in large-bore pores.

Adult↗
PubMedDate not supplied

Bonding to densely sintered alumina surfaces: effect of sandblasting and silica coating on shear bond strength of luting cements.

PURPOSE: An important determinant of the clinical success of ceramic restorations is the bond strength of the luting agent to the seating surface and the prepared tooth structures. Manufacturers of ceramic systems frequently specify both the luting agent and preluting treatment of the seating surface of the crown. Procera AllCeram is an all-ceramic crown comprising a porcelain-veneered coping of densely sintered, high-purity aluminum oxide. This study evaluated the shear bond strength of 4 luting agents: zinc-phosphate, glass-ionomer, resin-modified glass-ionomer, and resin cement (dual cured) to Procera aluminum oxide coping material. The luting agents were subjected to different surface treatments: untreated, sandblasted, or silica coated by the Rocatec system. MATERIALS AND METHODS: Cylindric and cubic specimens of the coping material were luted together, and the shear force necessary to separate the cylinder from the cube was measured with a universal testing machine. The surfaces of the specimens were also analyzed. RESULTS: No significant differences were recorded for the shear bond strengths of the luting agents to the untreated aluminum oxide. Glass-ionomer and the resin-modified glass-ionomer cements had the highest values (4.2 +/- 2.5 MPa and 4.3 +/- 1.9 MPa, respectively), and the lowest were 3.3 +/- 2.3 MPa for the resin cement and 3.2 +/- 1.0 MPa for the zinc-phosphate cement. Similar results were recorded for the sandblasted aluminum oxide surfaces, except with the glass-ionomer, which was significantly higher (12.9 +/- 2.4 MPa). For all 4 luting agents, the highest shear bond strength values were recorded for the silica-coated specimens; the highest was for the resin cement, at 36.2 +/- 7.8 MPa. CONCLUSION: The bond strengths between resin cement and aluminum oxide specimens treated by the Rocatec system were significantly higher than those of the other materials and surface treatments evaluated.

Aluminum Oxide↗
PubMedDate not supplied

Two-year follow-up study of Procera-ceramic fixed partial dentures.

PURPOSE: The aim of this prospective study was to determine whether a machine-fabricated titanium fixed partial denture veneered with a low-temperature fused porcelain is an acceptable treatment modality. MATERIALS AND METHODS: The study originally included 25 patients with 37 fixed partial dentures of three to seven units, with a total of 151 units including 98 abutments. A clinical examination using the California Dental Association quality evaluation system and radiologic examination and registration of complications was conducted at the time of insertion and after 1 and 2 years. RESULTS: After 2 years, 123 units (including 80 abutments) remained for examination. Twenty-eight units (including 18 abutments) were lost during the follow-up period. The losses were because of drop-out (eight cases), root fracture (two cases), caries (six cases), and periodontitis (two cases). One fixed partial denture fractured after 18 months and was therefore remade. In all, porcelain fractures occurred in two patients, both with severe parafunctional habits. At baseline, the California Dental Association rating system for marginal integrity was "excellent" for 72 abutments and "acceptable" for 26 abutments. At the 2-year follow-up the corresponding rating was "excellent" for 46 abutments, "acceptable" for 30 abutments, and "not acceptable" for four abutments. The latter marginal defects were corrected with restorations. For surface and color the corresponding ratings were "excellent" for 137 units and "acceptable" for 14 units at baseline, and "excellent" for 80 units and "acceptable" for 43 units at the 2-year follow-up. Bleeding index increased from 24% at baseline to 33% after 2 years. CONCLUSION: The study confirms that for an observation period of 2 years, fixed partial dentures made by the Procera method seem to be an acceptable treatment modality. They are a suitable alternative to fixed partial dentures with porcelain fused to high-noble alloys.

Adult↗