Biomedical subjects

E C Lönnroth

Publications and source records attributed to E C Lönnroth.

8 recordsLinked to original sources

PubMed2001

Cytotoxicity of dental glass ionomers evaluated using dimethylthiazol diphenyltetrazolium and neutral red tests.

The purpose of this study was to assess the cytotoxicity of some commonly used glass ionomers. Three chemically cured glass ionomers (Fuji II, Lining cement, and Ketac Silver) and one light-cured (Fuji II LC) were tested. Extracts of mixed non-polymerized materials and polymerized specimens were prepared in accordance with ISO standard 10993-12. The polymerized specimens were cured and placed either directly in the medium (freshly cured), left for 24 h (aged), or aged plus ground before being placed in the medium. The cytotoxicity of extracts was evaluated on mouse fibroblasts (L, 929), using dimethylthiazol diphenyltetrazolium (MTT) and neutral red (NR) assays. Further, the concentrations of aluminum, arsenic and lead were analyzed in aqueous extracts from freshly cured and aged samples, and the fluoride levels analyzed in aqueous extracts from freshly cured samples. All extracts except that of non-polymerized Ketac Silver were rated as severely cytotoxic in both assays. Extracts of polymerized material were significantly more cytotoxic than extracts of non-polymerized material. All freshly cured glass ionomers released aluminum and fluoride concentrations far above what is considered cytotoxic (aluminum >0.2 ppm and fluoride >20 ppm). Extracts from freshly cured Lining Cement contained the highest concentrations of aluminum and fluoride (215 ppm and 112 ppm). Extracts from freshly cured Ketac Silver had the lowest concentrations of aluminum and fluoride but the highest of lead (100 ppm). It can be concluded that all extracts from non-cured, freshly cured, and aged glass ionomers contained cytotoxic levels of substances. Curing did not reduce the toxicity significantly.

Aluminum↗

PubMed2001

Users' demands regarding dental safety glasses. Combining a quantitative approach and grounded theory for the data analysis.

Eye infections are common among dentists and many are concerned, but few are using proper eye protection. To understand users' demands behind the low use of safety glasses, all dental teams in Sweden were asked which factors they found most important when choosing dental safety glasses, and rate the importance of 31 statements regarding ergonomic aspects of dental safety glasses in a questionnaire. Data were analysed using the Grounded Theory and a quantitative approach. Results showed that dentists ranked the visual aspects as most important and chair assistants the protective aspects. The highly visual demanding work performed by dentists requires safety glasses that are not yet available on the market, which might explain the low use.

Attitude of Health Personnel↗

PubMed1999

Evaluating the potential occupational hazard of handling dental polymer products using the HET-CAM technique.

The irritation potencies of 8 dental polymer products, used as dental restorative materials, adhesives, or temporary constructions, were tested using the HET-CAM (hen's egg test-chorioallantoic membrane) technique. Liquid and powder components, and extracts of cured and freshly mixed non-cured materials of 5 glass ionomers, 1 bonding, 1 composite, and 1 cold-cured acrylate were examined. Results showed that the liquid component of all products had a strong irritation capacity but powder suspensions and extracts from cured and freshly mixed non-cured materials had no effect on the CAM. Thus, dental personnel who handle liquid and powder manually are exposed to components with a high irritation potential, in contrast to patients who are exposed to the cured and mixed non-cured materials with low irritation potential. This illustrates the importance of safe handling procedures and practices for dental personnel who handle non-cured polymers manually.

Animals↗

PubMed1998

Hand dermatitis and symptoms from the fingers among Swedish dental personnel.

Hand dermatitis among dental personnel has been an issue in recent years. Dental personnel manually handle polymer materials which are known to irritate skin, and also cause allergy. In addition, dental personnel wash their hands frequently, and use latex gloves, and are therefore at risk to develop hand dermatitis. To survey the occurrence of hand dermatitis among dental personnel, questionnaires were sent to all dental teams (dentist + chair assistant) working in the two northern Swedish counties. Referents were; researchers, teachers, and secretaries from a university and high schools, from the same geographical area. The response rate was 76% for dental teams, and 66% for referents. The results show that male dentists reported a significantly higher prevalence of hand dermatitis than male reference. In contrast to chair assistants and referents, dentists (both male and female) reported a higher extent of hand dermatitis on the left than on the right hand. There was an association between hand dermatitis among dental personnel and; age, eczema in childhood, and hay fever but, not with; sex, asthma, frequent washing of the hands, and glove use. Whitening of the fingers increased with increasing age among dental personnel. Pricking was also associated with frequent glove use. Pricking of the fingers was associated with sex, and 3.5 times more common among female dental personnel than male dentists. Numbness of the fingers, and finger pain was reported by more dentists than chair assistants and referents.

Adult↗

PubMed1998

Adverse health reactions in skin, eyes, and respiratory tract among dental personnel in Sweden.

Dental personnel manually handle products that contain monomers. Several studies have documented adverse health effects after exposure to such products. Gloves made of vinyl or latex are easily penetrated by monomers. Ordinary glasses, or visors, do not protect against vapour from polymer products. Dental face masks filter out about 40% of respirable particles. To survey the prevalence of asthma, atopic dermatitis, conjunctivitis, hay fever/rhinitis, and hand eczema among dental personnel, a questionnaire was distributed to all dental teams in Northern Sweden. Referents were researchers, teachers, and secretaries from the same geographical area. The response rate was 76% for dental teams, and 66% for referents. The results show a significantly higher prevalence of conjunctivitis, and atopic dermatitis among dentists, both male and female. Hypersensitivity to dental materials was reported by significantly more dental personnel than by referents.

Adult↗

PubMed1997

Use of polymer materials in dental clinics, case study.

Dentistry uses a variety of different polymer materials. Dental polymer materials are based on methacrylate, its polymer, and polyelectrolytes. The setting of restorative materials and adhesives is initiated chemically by mixing two components or by light. In both cases, polymerisation is incomplete and monomers, not reacted, release. Studies have documented that monomers may cause a wide range of adverse health effects such as irritation to skin, eyes or mucous membranes, allergic dermatitis, asthma, parenthesise in the fingers, and disturbances from central nervous system such as; headache, pain in the extremities, nausea, loss of appetite, fatigue, sleep disturbances, irritability, loss of memory and changes in blood parameters. Dental personnel are occupationally exposed when handling the non reacted monomers. The use of gloves do not give enough protection as monomers, released from the material, easily penetrate all gloves used in dentistry. Face masks do not prevent inhalation of monomers. Ordinary glasses do not protect the eyes against vapor from monomers. The result from this study demonstrate the need for the development of ergonomic procedures and practices for safe handling of such materials in dental clinics.

Asthma↗

PubMed1996

Dental clinics--a burden to environment?

To estimate environmental burden of mercury from dental clinics, a survey was conducted in 1993 at dental clinics in northern part of Sweden. Factors regarding amalgam separators, maintenance and disposal of collected sludge, age of clinics, cleaning of waste pipes, and sorting and handling of amalgam contaminated products were investigated. The result showed that many were not familiar with maintenance of the amalgam separator. A majority, 68%, were working in clinics older than 10 years, but only 9% reported that waste pipes had been cleaned or changed. Classification of amalgam contaminated products as high-risk and low-risk waste differed a lot, as well as handling of waste products. The result shows that there is need for more information and attention to all individuals working in Dental Care on how to reduce environmental burden of mercury from dental clinics.

Adult↗

PubMed1995

Amalgam in dentistry. A survey of methods used at dental clinics in Norrbotten to decrease exposure to mercury vapour.

A survey was conducted on the possible factors influencing exposure to mercury vapour during the handling of amalgam and amalgam contaminated products at dental clinics in Norrbotten, the northern part of Sweden, as well as the current methods being used to minimise, if not prevent such exposures. Increased room temperature, a serious problem when working with amalgam, was the most common complaint from the dental personnel reflecting the observation that ventilation in most clinics was far from being satisfactory. However, methods of treating amalgam-contaminated waste products as well as the classification of products as high- or low-risk wastes also differed a lot. The results further showed that although majority of the dental personnel showed concern on the possible hazards of mercury vapour exposure and were interested in having the level of mercury vapour measured in their clinics, very few had access to any protective equipment against it. And among the few who had some forms of protective wear, most found the equipment disturbing and disruptive of work performance.

Adult↗