Biomedical subjects

A Hensten-Pettersen

Publications and source records attributed to A Hensten-Pettersen.

At least 19 recordsLinked to original sources

PubMed1999

Dental workplace exposure and effect on fertility.

OBJECTIVES: This study assessed occupational exposure in dental surgeries on the basis of the reported use of dental materials and techniques and applied waiting-time-to-pregnancy methodology to study fertility in relation to the occupational exposure. METHODS: Data were collected retrospectively using a self-administered postal questionnaire addressing the occupational and reproductive history of the participants. The study groups consisted of 558 female dental surgeons and 450 high school teachers that had given birth in Norway to at least 1 living child. The present study comprised data from a total of 1408 pregnancies. The effects of practicing dentistry and of the given workplace exposure on fertility were analyzed with the discrete proportional hazard regression method. RESULTS: Most of the female dental surgeons were using amalgam for fillings during the period they tried to conceive, and 1/3 placed more than 50 fillings a week. Tooth-colored fillings were in limited use. Prior to 75% of the pregnancies, the dental surgeons reported handling chloroform-based root canal sealers. Forty percent of the dental surgeons were daily exposed to disinfectants containing ethanol and benzene. No difference was found in fertility between the dental surgeons and the high school teachers. Exposure to mercury, chloroform, and benzene was not associated with decreased fertility, except for a possible effect of mercury in the last pregnancy of multiparous dental surgeons. CONCLUSIONS: Occupational exposures had no clear adverse effects on fertility among the female dental surgeons studied.

Dental Amalgam↗

PubMed1998

Skin and mucosal reactions associated with dental materials.

The selection of dental materials for specific treatment purposes is primarily based on their physical properties. The composition of materials available indicates that there is the potential for adverse biological effects. The amounts of substances released are usually too low to cause any overt systemic toxic effects. However, many of the chemicals used in dentistry are irritating and may cause local damage. Also, in reactions mediated via the amplifying mechanisms of the immune system, small amounts may lead to clinical manifestations of allergic contact dermatitis and urticaria. A special problem in the diagnosis of adverse events occurs when intraoral exposure leads to generalized urticarial reactions. Due to a low level of suspicion, extraoral reactions are rarely associated with dental treatment modalities. Occupational dermatoses represent a serious problem, especially the development of an allergy to constituents of the resin-based filling materials and adhesives. The monomers of resin-based materials are volatile and penetrate latex and vinyl gloves easily. Allergic contact dermatitis related to resin-based materials may be occupationally disabling.

Adhesives↗

PubMed1997

Salivary nickel and chromium in subjects with different types of fixed orthodontic appliances.

The aim was to investigate nickel and chromium concentrations in saliva of patients with different types of fixed appliances. Saliva samples were collected from 47 orthodontic patients, ages 8 to 30 years. Four samples from each subject were collected: (1) before insertion of the appliance, (2) 1 to 2 days after, (3) 1 week after, and (4) 1 month after insertion of the appliance. A considerable variation in the concentrations of both nickel and chromium was observed. No significant differences were found between the no-appliance samples and the samples obtained after insertion of the appliances. The results suggest that nickel and chromium concentrations of saliva are not significantly affected by fixed orthodontic appliances during the first month of treatment.

Adolescent↗

PubMed1997

Surface analysis of nickel-titanium archwire used in vivo.

OBJECTIVES: The surface quality of an archwire is a critical factor in the prevention of corrosion. This study was conducted to evaluate and assess the surface of as-received and used nickel-titanium archwires for evidence of corrosion, and to analyze possible corrosion products. METHODS: Round 0.4 mm and square 0.4 mm x 0.55 mm nickel-titanium archwires from two manufacturers were subjected to elemental analysis, examined, and photographed in a scanning electron microscope with an EDAX unit. The used wires had been in service from 3 wk to 4 mon. There were no systematic differences in surface topography or composition between the as-received and used wires. RESULTS: The examination revealed undulated surfaces with manufactural scratches and crevices. The surface quality within the same archwire varied slightly, with different smoothness in the anterior and posterior regions. No systematic discernible difference was found between used and as-received arch wires. The analyses of different areas on the used archwires revealed no differences in the metal composition. SIGNIFICANCE: The surface defects found on the as-received wires were evidently not large enough to act as sites for corrosion attack.

Corrosion↗

PubMed1996

Nickel allergy in adolescents in relation to orthodontic treatment and piercing of ears.

The aim of this study was to investigate the frequency of nickel hypersensitivity in adolescents in relation to sex, onset, duration and type of orthodontic treatment, and the age at which ears were pierced. The subjects were 700 Finnish adolescents, from 14 to 18 years of age, of which 476 (68%) had a history of orthodontic treatment with metallic appliances. The study consisted of patch-testing for a nickel allergy and a patient history obtained by a questionnaire and from patient record. The frequency of nickel sensitization in the whole group was 19%. Nickel allergy was significantly more often found in girls (30%) than in boys (3%) and in subjects with pierced ears (31%) than in those with no piercing of ears (2%). Orthodontic treatment did not seem to affect the prevalence of nickel sensitization. None of the girls who were treated with fixed orthodontic appliances before ear piercing showed hypersensitivity to nickel, whereas 35% of the girls who had experienced ear piercing before the onset of orthodontic treatment were sensitized to nickel. The results suggest that orthodontic treatment does not seem to increase the risk for nickel hypersensitivity. Rather, the data suggests that treatment with nickel-containing metallic orthodontic appliances before sensitization to nickel (ear piercing) may have reduced the frequency of nickel hypersensitivity.

Adolescent↗

PubMed1996

Profile of work-related health complaints among Swedish dental laboratory technicians.

The purpose of the present investigation was to assess the prevalence and nature of occupation-related health problems among Swedish dental laboratory technicians. A 4-page questionnaire listing seven groups of health complaints was completed by 489 male and 242 female technicians, representing 56% of the active members of their organization. Similar information from 163 males and 160 females with other occupations was used for comparison. The biannual prevalence of health problems among the technicians was 79%, comprising musculoskeletal (68%), dermal (34%), respiratory 31%, neurological (26%), systemic (19%) and eyesight/hearing problems (15%). Job-specific ergonomic and stress factors were responsible for musculoskeletal and neurological (finger) reactions whereas chemical insults, grinding dusts and indoor climate caused dermal, respiratory and systemic reactions. There was no age prevalence as regards health complaints, but female technicians consistently showed a large prevalence of musculoskeletal, dermal systemic and neurological complaints than their male counterparts (P < 0.05, chi2). A similar sex difference was also present in the control group. A considerable part of the reactions were perceived to be of minor importance, bringing the total biannual prevalence down to 57%. However, the prevalence of job-related health complaints was still higher among the technicians than in control groups for all indicators except systemic and eyesight/hearing problems. The profile of health complaints among dental laboratory technicians was characterized by musculoskeletal, neurological and dermal reaction, underlining the importance of job-specific ergonomic and chemical hazards. Only a few of the technicians had consulted medical personnel.

Adult↗

PubMed1995

Occupational health problems among dental hygienists.

A questionnaire survey on work-related health complaints was performed among dental hygienists. Valid information was received fom 189 hygienists, representing about half of all active members of the Norwegian Association of Dental Hygienists. Parallel information was received from similar number of female and male control persons in other occupations. The present report presents data on the nature and etiology of the chemically induced health complaints. About half of the hygienists had experienced one or more health problem of dermal, systemic, sensory (eye) or respiratory nature during the last year, as compared to 37% of the female and 19% of the male control group. The most frequent complaint was dermatoses of hands and fingers (37%), caused by different chemical, work-related factors. Latex gloves were responsible for 1/3 of these reactions. The role of immunological and irritant latex reactions were discussed and the prevalence of non-dermatological reactions compared with similar findings among women in other occupations.

Adult↗

PubMed1995

Biological testing of dental materials: development of national and international standards.

Testing of dental materials helps to ensure that they are of satisfactory quality. Most standardized testing programs have focused on the physical, chemical, and mechanical properties of the materials, and started at the National Bureau of Standards, USA, in 1919. The need for biological evaluation of dental materials became evident after some material-related adverse incidents. The first document concerning standardized testing of the biological properties of dental materials was published by the American Dental Association in 1972. During the last twenty-five years, increased attention has been focused on the evaluation of biological properties by standardized testing. The development of standards concerning biological testing of dental materials since 1972 at the national and international level is described.

American Dental Association↗

PubMed1994

An assessment of the physical properties and biocompatibility of three silicone elastomers.

The physical properties of two room-temperature vulcanizing (RTV) silicones, A-2186 and Silbione 71556, and one high-temperature vulcanizing (HTV) material, Mollomed, were compared. The potential cytotoxicity of the silicone materials was assessed with the agarose overlay test. The properties that were investigated were tensile strength, percentage elongation, modulus, permanent set, tear strength, and hardness. The properties tested were selected because of their clinical significance for fabricating facial prostheses. The results of this study indicate that the A-2186 material has a better combination of high tear strength and elongation at break with a softer surface compared with Mollomed silicone, and Silbione 71556 silicone proved to be the weakest material. All materials demonstrated absence of cytotoxicity in the cell culture tests.

Analysis of Variance↗

PubMed1994

Effects of RTC-silicone maxillofacial prosthetic elastomers on cell cultures.

The use of a wide variety of materials in the construction of maxillofacial prostheses makes biocompatibility testing a necessity. However, the dental literature contains few reports of biocompatibility testing of maxillofacial prosthetic materials. The cytotoxic profiles of five room-temperature cross-linking (RTC)-silicone elastomers were investigated by means of two in vitro cell culture techniques. Mouse fibroblast cells (L929) were used, and the results indicated that RTC-silicone elastomers adversely affected cells in culture and that storage of samples for 1 week in saline solution did not alter this effect. Clinical follow-up of patients wearing prostheses made of these silicone materials is warranted to evaluate host reactions in long-term contact with human mucous membrane and skin tissue.

Animals↗

PubMed1994

Proliferation of nickel-sensitive human lymphocytes by corrosion products of orthodontic appliances.

Lymphocyte transformation tests were performed on peripheral blood taken from individuals with a history of contact dermatitis who also presented with a positive patch test to nickel sulphate, and from individuals with no history of contact dermatitis. The results implied that nickel leached out from metallic orthodontic appliances in sufficient amounts and of a chemical nature adequate to stimulate proliferation of lymphocytes from some of the nickel-sensitive subjects.

Analysis of Variance↗

PubMed1994

Allergenic potential of two orthodontic bonding materials.

The sensitization potential of two orthodontic bonding materials, one conventional premix product and one nonmix product, was evaluated by a modified guinea pig maximization test. The nonmix product, consisting of a liquid to be applied to the tooth surface and a paste which was placed on the bracket base, caused reaction in 50% of the tested animals. This material should be considered to be a possible cause of allergy in patients or professionals handling it.

Adhesives↗

PubMed1994

Possible side effects related to dental hygienists' treatment.

The aim of the present investigation was to obtain information on the repertoire of patient-related remedies and materials used by dental hygienists and on the frequency and nature of side effects observed among their patients. Norwegian hygienists received a questionnaire on dental remedies and materials used, the number of patients seen, and side effects observed during the past year and earlier. Information from 169 hygienists provided a list of remedies comprising fluoride-containing varnishes, polishing remedies, pit and fissure sealants, oral disinfectants, fluoride gels and solutions, and plaque-disclosing solutions. In addition, some hygienists used temporary dental materials, polyalkeonate/composites, and local anesthetic spray or ointment. Fourteen brands of latex gloves were used. Possible side effects of general and local nature were observed by 37 dental hygienists. Reactions associated with the application of Duraphat in children (> 1:1640) and contact with latex gloves in adult patients (> 1:3300) were most important. The findings are discussed with specific emphasis on the content of colophony in the fluoride varnish.

Adolescent↗

PubMed1993

Denture adhesives: cytotoxicity, microbial contamination, and formaldehyde content.

Denture adhesives are extensively used to enhance retention of dentures. Denture adhesives and their leachable components are ingested, but reports on the biologic aspects of denture adhesives are scarce. This study investigated some biological properties of 19 commercially available denture adhesives. The adhesives were assessed by the agar overlay technique and analyzed for microbial contamination and formaldehyde content. In the agar overlay test, all of the materials caused severe cytotoxic effects. Sabouraud dextrose agar was used for cultivation of fungi and tryptone soya broth for cultivation of aerobes, including fungi. Most of the samples tested showed microbial growth. The formaldehyde test revealed the presence of substantial amounts in four products and minor amounts in two products.

Adhesives↗

PubMed1993

Cytotoxic and antibacterial effects of orthodontic appliances.

The cytotoxic and antibacterial effects of orthodontic appliances were assessed. Metallic devices used in orthodontics, such as molar bands, brackets, and archwires were tested by the agar overlay cytotoxicity test with mouse fibroblast cells. The same devices were tested for antibacterial effect with Streptococcus mutans and S. sanguis. The multicomponent devices, which are bonded with silver- and copper-based brazing alloys, were more cytotoxic than the single-component devices, probably because copper is more cytotoxic than nickel. The devices had a definite, but low, antibacterial effect, as compared with the 0.05% chlorhexidine positive control. A cytotoxic effect of the devices per se might contribute to a localized gingivitis. It is uncertain whether orthodontic devices have any significant inhibitory effect on dental plaque viability.

Animals↗

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↗