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Biomedical subjects

A Hensten-Pettersen

Publications and source records attributed to A Hensten-Pettersen.

At least 19 recordsLinked to original sources
PubMed1992

Composition and in vitro corrosion of orthodontic appliances.

The high incidence of nickel allergy and the increasing use of nickel-containing dental biomaterials has been of growing concern. The purpose of this investigation was to analyze different types of alloys used in orthodontics, and to study whether nickel and chromium will be released from these alloys when stored in physiologic saline. Face-bows, brackets, molar bands, and arch wires were analyzed. Most of the different parts in the face-bows, brackets, and molar bands were similar to conventional 18/8 stainless steel. Except the wires, most appliances included a variable amount of silver solder, the greatest in face-bows. After 14 days in 0.9% sodium chloride (NaCl), the largest amount of nickel and chromium were leached out from the face-bows and the least amount from the arch wires. Soldered stainless steel face-bows seemed to be very susceptible to corrosion. The release of nickel seemed to be related to both the composition and the method of manufacture of the appliances, but the release was not proportional to the nickel content.

Chromium↗
PubMed1992

Cytotoxic effect of orthodontic appliances.

The use of orthodontic appliances may contribute to local gingivitis, often attributed to increased plaque retention. Gingivitis of bacterial origin cannot clinically be distinguished from local tissue irritation caused by corrosion products. The purpose of this investigation was to assess the cytotoxic effect of various metallic components used in orthodontics. Multicomponent devices such as facebows, molar bands, and brackets along with single-component brackets and archwires were tested by the agar overlay cytotoxicity test with mouse fibroblast cells. None of the archwires caused any cytotoxic effect, even though some contained 54 per cent nickel. However, the multi-component devices, which were joined with silver- and copper-based brazing alloys were more cytotoxic than the single-component devices. Copper is more cytotoxic than nickel, which could explain the greater cytotoxic effect of the samples with brazing materials. It is speculated that cytotoxic corrosion products from orthodontic appliances might contribute to localized gingivitis.

Animals↗
PubMed1992

Casting alloys: side-effects.

Side-effects from dental materials are a minor problem, but should be recognized. In recent questionnaire surveys about side-effects, the incidence was estimated to be 1:300 in periodontics and 1:2600 in pedodontics. None of these reactions was related to dental casting alloys. In prosthodontics, the incidence was calculated to be about 1:400, and about 27% were related to base-metal alloys for removable partial dentures (cobalt, chromium, nickel) and to noble/gold-based alloys for porcelain-fused-to-metal restorations. The complaints consisted of intra-oral reactions (such as redness, swelling, and pain of the oral mucosa and lips), oral/gingival lichenoid reactions, and a few instances of systemic reactions. In orthodontics, the incidence was 1:100, and most reactions (85%) were related to metal parts of the extra-oral anchorage devices. Even though the extensive use of base-metal alloys has been of major concern to the dental profession, relatively few case reports substantiate this concern. Allergy to gold-based dental restorations has been more commonly reported. Palladium-based alloys have been associated with several cases of stomatitis and oral lichenoid reactions. Palladium allergy seems to occur mainly in patients who are very sensitive to nickel. All casting alloys, except titanium, seem to have a potential for eliciting adverse reactions in individual hypersensitive patients. Tolerance induction may be a possible benefit of the use of intra-orally placed alloys. In non-sensitized individuals, oral antigenic contacts to nickel and chromium may induce tolerance rather than sensitization. A variety of systemic diseases and reactions has been claimed to be caused by dental materials. The claims are generally poorly documented.

Cobalt↗
PubMed1991

Perceived side effects of biomaterials in prosthetic dentistry.

The present questionnaire survey of side effects of biomaterials in prosthodontics had a response rate of 64%. There were occupational health problems associated with a variety of dental materials, especially acrylic resins, eugenol-containing materials, and elastomer impression materials. Most reactions were mild to moderate dematoses of the fingers or hands, but one prosthodontist had to cease practice due to a severe allergic reaction to acrylic resin materials. Of the respondents, 8% had experienced reactions to latex gloves. Nondermatologic reactions seemed to be transient, affecting the eyes, respiratory pathways, or occasionally causing generalized symptoms. These reactions were mainly attributed to vapors from acrylic resin monomers or cyanoacrylates. Adverse reactions in patients, tentatively estimated to be one out of 300, were observed by 40% of the prosthodontists, mostly as intraoral reactions. Acrylic resins, eugenol-containing cements, base metal alloys, mercury, gold, polyether/epimine based materials, and tissue conditioners were cited as causes. Skin contact with the dentists' latex gloves elicited extraoral reactions in some patients.

Biocompatible Materials↗
PubMed1991

In vitro cytotoxicity of tissue conditioners.

The cytotoxicity of four commercial tissue conditioners was evaluated by the agar overlay method. Every material either fresh or stored for 1 hour, 24 hours, 8 days, or 15 days, showed some degree of cytotoxicity. Coe Comfort and Kerr FITT materials exhibited marked cytolysis, whereas GC Soft-Liner and Visco-gel materials caused a decolorized zone with minimal cell damage. Based on the sum of reaction indices, the tissue conditioners tested seemed to be more cytotoxic than autopolymerizing denture base resins. Further analyses are needed to identify the cytotoxic components that continued to leach out from the tissue conditioners for at least 15 days.

Acrylic Resins↗
PubMed1991

Occupational health complaints and adverse patient reactions as perceived by personnel in public dentistry.

A questionnaire survey on health complaints experienced by personnel in public dentistry was undertaken in 1979 and repeated in 1988/89. The reply rates were about 80% and 83%. In both surveys, about one half of the personnel reported occupation-related health complaints, a majority of which were dermatoses of hands and fingers. The dermatoses were attributed to seasonal air quality problems, or to contact with chemically active substances relevant to hygienic measures, treatment patterns, or other activities connected with the running of a dental clinic. The majority of the dermatoses were probably irritative. Some presumably hypersensitivity reactions occurred after handling of dental materials. Latex gloves, which were in general use only at the time of the last survey, seemed to have prevented some dermatoses formerly attributed to handwashing procedures. However, latex gloves per se had also induced dermatoses. Non-dermatological ailments of a transient nature comprised eye, respiratory, or systemic reactions and were connected with volatiles from X-ray liquids, methylmethacrylate monomer, and disinfectants. Adverse patient reactions occurred at a frequency of about one per 2600 treated patients. The observations comprised skin reactions (head/face), gingival/mucosal ulcerations, and sometimes systemic/urticarial reactions. The reactions were associated with the use of local anesthetics, orthodontic appliances, and other biomaterials. Two reactions were related to contact with the dentists' latex gloves.

Adult↗
PubMed1991

Toxic effects of dental materials.

Dental materials and clinical accessories may potentially cause adverse reactions in dentists, auxiliaries or patients. The introduction of new dental materials and a general awareness of adverse effects has been accompanied by an increase in the number of complaints related to dental treatment and to occupational exposure. Resin-based materials with various monomers, used as restorative composite materials, orthodontic adhesives and appliances, prosthodontic resins and impression materials, have all been involved. Reactions to metals used in extra-oral appliances in orthodontics seem to be relatively frequent, but few reactions have been reported following the use of other alloy systems. Some reactions may be due to toxic or allergic effects, but some are unexplained. Adverse reactions to any substance will usually be detected first in a setting where the exposure is greatest. This also holds true for dentistry, where some of the adverse reactions may be due to lack of knowledge about the toxic, irritant and allergenic properties of dental materials.

Allergens↗
PubMed1990

Assessment of adverse reactions to prosthodontic materials.

In 1978 five cases of so-called hypersensitivity reactions to Scutan and two to Impregum were reported (Dahl, 1978). The aim of the present study was to assess whether hypersensitivity or cell-mediated immune reactions were associated with the adverse clinical reactions in these patients or in others who had experienced the same reactions. Epicutaneous patch testing and lymphocyte transformation tests were carried out in a total of 13 individuals. The findings were difficult to interpret, because there was no consistent association between skin reactions and cell-mediated immune responses in subjects with suspected allergies. Other possible reasons for the reactions originally recorded were therefore discussed. It was concluded that adverse reactions associated with immune-mediated, delayed type hypersensitivity reactions may be elicited by prosthodontic materials, but other pathogenic mechanisms and aetiological factors responsible for the reactions observed should also be considered.

Adult↗
PubMed1990

Guinea pig maximization test with a polyether impression material.

Adverse reactions to a polyether rubber impression material introduced in the mid-sixties have been reported in the literature. Most of the reports are inconclusive regarding the distinction between allergic and toxic responses. The aim of this study was to assess the allergenic potential of this material using a guinea pig maximization test. Ten guinea pigs in the experimental group were sensitized in two steps. First, an extract of the material was injected intradermally, and 7 days later, the material mixed in petrolatum was applied topically. After another 2 wk test solutions were applied, and the skin response was evaluated by visual inspection. Ten nonsensitized animals served as controls. From the challenge test it was evident that the catalyst as well as the freshly mixed material elicited positive skin reactions interpreted as being delayed hypersensitivity reactions. The findings indicate that the material contained substances which could be classified as strong to extreme sensitizers. Some of the adverse reactions seen in connection with the use of this material might well be related to delayed hypersensitivity reactions.

Allergens↗
PubMed1990

The role of biomaterials as occupational hazards in dentistry.

Many of the biomaterials and auxilliary products used in dentistry are chemically and biologically reactive and may be of concern in occupational safety programmes. Observations from 1936 to 1975 indicated that most occupational problems were related to skin contact with procaine, soaps, eugenol, iodine, formalin, phenol, and other disinfectants. Methyl methacrylate monomer was identified as an irritant and allergen in the later part of this period. Investigations from 1975 to 1985 indicated that disinfectants and detergents were still important causes of dermatoses, whereas reactions to procaine had been replaced by reactions to pantocaine. Furthermore, adverse reactions to methyl methacrylate monomer and to elastomeric impression materials had replaced the former iodine, tricresol and eugenol reactions. In recent studies the frequency of occupation-related dermatoses varied from 21 per cent to 43 per cent, depending on the prevailing material usage in the various specialties. Reactions to local anaesthetics seemed to have disappeared. Transient, irritative reactions of the eyes and airways have been observed, mostly associated with exposure to volatiles from resin-based materials, X-ray chemicals and cleansers. The occupational problems related to biomaterials in dentistry seem to have been fairly constant over the years, reflecting the type of materials in common use, and with dermatological disorders being a tenacious companion. Neuropathological conditions in dental technicians have been associated with prolonged exposure to vapours of methyl methacrylate monomer. The more recent extensive use of volatile resin-based materials, and the use of protective gloves seems to have created new problems that need to be investigated.

Biocompatible Materials↗
PubMed1989

Aluminum-induced granulomas in a tattoo.

A patient who developed localized, granulomatous reactions in a tattoo is described. With the use of scanning electron microscopy and energy dispersive x-ray microanalysis, both aluminum and titanium particles were found in the involved skin sections. Intradermal provocation testing with separate suspensions of aluminum and titanium induced a positive response only in the case of aluminum. Examination by scanning electron microscopy and energy dispersive x-ray microanalysis of the provoked response established aluminum as the only nonorganic element present in the test site tissue. This is the first report of confirmed aluminum-induced, delayed-hypersensitivity granulomas in a tattoo.

Adult↗
PubMed1989

Occupational health problems and adverse patient reactions in orthodontics.

The purpose of the present investigation was to study the nature and frequency of adverse reactions to materials and procedures among orthodontists and their patients. A questionnaire about this topic was mailed to practicing members of the Norwegian Orthodontic Society, of which 137 (about 75%) responded together with 127 chairside assistants. About half of the orthodontic personnel had experienced adverse reactions. The majority of the problems were dermatoses, comprising dryness, redness, itching, thickening, reduced tactile sensitivity, fissuring, soreness/desquamation and pain of hands and fingers. The residual were respiratory reactions, eye reactions or reactions of a general nature. Many of the dermatoses were of moderate severity, attributed to (seasonal) air/ventilation associated problems. Other frequent causes were hand washing procedures, work involving composites and acrylics (orthodontists), or work involving model materials, alcoholic disinfectants, latex gloves, alignates etc. (assistants). For both groups the most severe dermatological reactions were associated with unspecified allergies, acrylics and composites. Non-dermatological reactions also reflected the different working pattern and exposure to materials in orthodontics; acrylic monomer topping the list. The orthodontists had observed 425 patients with dermal reactions and 67 patients with intraoral/systemic reactions, indicating a prevalence of about 1 per cent. Dermal reactions included redness, eczema, itching and fissuring in facial, neck or perioral areas, mostly attributed to metallic parts of extraoral appliances, with some exceptions (elastics, neck pillows, head caps). Intraoral reactions consisted of redness, soreness and swelling of the oral mucosa, gingiva and/or lips and were associated with metal brackets, labial wires, bonding procedures or acrylic appliances.

Adolescent↗
PubMed1989

Occupational health problems and adverse patient reactions in periodontics.

The purpose of the present survey was to assess the nature and extent of adverse reactions to materials and procedures among personnel in periodontal practice and their patients. A questionnaire was mailed to practicing members of the Swedish Society of Periodontists. A total of 85, about 65%, responded together with 44 dental hygienists and 64 chairside assistants. 42% had experienced adverse reactions. The majority of complaints were related to dermatoses of the hands and fingers. The remainder were respiratory or eye reactions. A specifical problem characteristically involving the hygienists, was musculoskeletal stress reactions. Many of the dermatoses were of moderate severity, and were associated with seasonal, air-ventilation problems or were unexplained. The most severe reactions were reported by atopic persons. The reactions were attributed to hand washing procedures, the use of latex gloves and other disposable personal equipment such as face masks and caps. Reactions attributed to dental materials or local anaesthetics, characteristic of other reports from general dental practice, were absent. The survey indicated that personnel in periodontal practice have problems similar to many other categories of health personnel. Patient reactions were encountered at a frequency of 1 every other year per periodontist. The majority were intraoral reactions to chlorhexidine mouthrinses. Other patient reactions were associated with exposure to latex gloves, eugenol-containing periodontal packs, methacrylates and nickel-containing instruments. 2 instances of anaphylactoid reactions to latex gloves were encountered.

Adult↗
PubMed1987

Tissue reactions to implanted orthodontic wires in rabbits.

Tissue response to a Fe-Cr-Ni and a Co-Cr-Ni orthodontic wire, in the as-received state and with silver soldered joints, was investigated. Specimens with polytetrafluoroethylene (PTFE) as a reference material were implanted in the subcutaneous tissue of rabbits. Six rabbits were sensitized to nickel, four animals were sham-sensitized, and two were left untreated. The results showed that the as-received wires gave no tissue response relative to the PTFE control. In soldered specimens that were moderate to extreme reactions adjacent to the soldered joint and around the wire portion as well. The soldered Co-Cr-Ni wire elicited the most severe reactions, most pronounced in the nickel-sensitized animals. The agar overlay cell culture test of some retrieved implants showed pronounced cytotoxicity of the soldered specimens. Leachable toxic components of the silver solder seemed to be of major importance in the observed cell culture and tissue response to the soldered specimens.

Animals↗
PubMed1986

In vitro testing of dental materials by means of macrophage cultures. I: Methodological aspects.

Macrophages play a central role in the pathogenesis of inflammation. In addition, activated macrophages are the first cells to come in contact with foreign particles in tissue. In the present study the applicability of macrophages for in vitro biological screening of dental materials was tested. Monolayers of murine peritoneal macrophages were prepared. After three days culture the macrophages were inoculated with alloy particles prepared from silver and tin (Ag3Sn), the gamma-phase of dental silver-amalgam. After different inoculation periods the macrophages were fixed and examined with phase contrast microscopy, scanning electron microscopy, and energy dispersive x-ray analysis. Comparison with phagocytosis of particles injected intraperitoneally was also performed. Macrophage cultures inoculated with Latex particles served as controls. Ten minutes after inoculation with alloy particles, about 58% of the macrophages had ingested particles. EDAX-analysis indicated that the phagocytized alloy particles contained both silver and tin in the same proportions as in the original alloy. When the cultures had been inoculated for ten days, however, a marked reduction in phagocytosis was observed probably due to cytolysis of those macrophages which initially had phagocytized the alloy particles. The results indicate that, although the Ag3Sn alloy particles at all the time intervals studied were phagocytized more slowly and to a lesser extent than the Latex particles, the method could be of value in studying the biocompatibility of dental materials available in particulate form.

Animals↗
PubMed1986

In vitro testing of dental materials by means of macrophage cultures: II. Effects of particulate dental amalgams and their constituent phases on cultured macrophages.

It is known that macrophages play an important role in the removal of foreign particulate matter from tissue. When powdered dental amalgam is introduced into the soft tissues an amalgam tattoo is formed due to the intracellular degradation of amalgam by macrophages and their polykaryons. It was therefore feasible to study the effects of particulate amalgams as well as their individual phases on macrophages in vitro. The parameters compared were rate of the phagocytosis, changes of cellular morphology, and release of lactate dehydrogenase (LDH) to demonstrate plasma membrane permeability. It was shown that all the alloys except the Sn8Hg particles (gamma 2-phase) and gamma 2-containing Revalloy were effectively phagocytized by macrophages, and the alterations in cellular morphology were slight during the first day. Prominent cellular damage was seen in cultures treated with particulate Ag2Hg3 (gamma 1-phase) and Revalloy for 1 week. A slight increase in LDH activity in the medium was seen one hour after the alloy treatment. The LDH activities due to the amalgam treatment increased in the order Dispersalloy less than Revalloy less than Sybraloy. Intraperitoneal phagocytosis did not cause any morphological changes in macrophages, but the per cent of phagocytosis was diminished.

Animals↗