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Biomedical subjects

Nils Roar Gjerdet

Publications and source records attributed to Nils Roar Gjerdet.

12 recordsLinked to original sources
PubMed2006

[Contact allergy in the mouth].

Contact allergy is not frequently seen in the oral mucosa. Oral lichenoid reactions in conjunction with dental restorations, particularly amalgam fillings, are among the most common affections. Subjective symptoms such as burning mouth syndrome, could have an allergic component, but the etiology is unclear and complex. Food additives and oral hygiene products can cause oral lesions of allergic nature. Patch testing is the routine diagnostic tool used by dermatologists, though the interpretation of the clinical relevance is crucial.

Dental Materials↗
PubMed2005

A follow-up study of patients with subjective symptoms related to dental materials.

OBJECTIVES: The extent to which substances released from dental materials cause adverse health effects and whether removal of dental materials results in improvement of health is a matter of dispute. The aim of the study was to investigate changes in the intensity of subjective symptoms after replacement of dental materials in patients referred for adverse reactions related to dental materials, and to compare the profiles of symptoms with those found in the general population. METHODS: Information was obtained from 142 patients referred to the Dental Biomaterials Adverse Reaction Unit in Bergen, Norway. At the time of examination, all patients completed a questionnaire regarding a range of subjective symptoms. A follow-up questionnaire was sent to all patients 1 to 2 years later. Similar questionnaires were sent to a reference group of 800 persons drawn from the general population. RESULTS: The follow-up questionnaires were completed and returned by 84 patients, and 441 persons in the reference group. The patient group presented higher symptom indices than the reference group (P<0.001). Generally, there was some decrease in the intensity of different symptoms in patients who had replaced dental materials. The decrease was evident regarding intraoral symptoms (P=0.022) and total symptom index (P=0.041). The group of patients who had replaced materials still had significantly higher symptom indices than those of the reference group. Patients who had not replaced dental materials did not present any reduction in symptom indices. CONCLUSION: The pattern of symptoms was similar for the groups investigated. At the group level, the intensity of local and some general subjective symptoms was reduced after replacement of the materials, but not to the level found in the general population.

Chi-Square Distribution↗
PubMed2004

Pinealectomy induces malformation of the spine and reduces the mechanical strength of the vertebrae in Atlantic salmon, Salmo salar.

This study describes the long-term effects of surgical ablation of the pineal gland on the spine of 3-yr-old Atlantic salmon (Salmo salar L.) with a mean weight of 3.2 kg. Radiographic examinations showed that 82% of the pinealectomized fish developed marked lateral (scoliosis) and dorso-ventral spinal curvatures. The proportions of the individual vertebral bodies and their mechanical properties were also altered. The stiffness, yield limit and resilience of the vertebral bodies, as measured by compression in the cranio-caudal direction, were significantly lower in the pinealectomized than in the sham-pinealectomized group. Calcium, phosphorous and total mineral content of the vertebral bodies were also significantly lower in the pinealectomized fish, while these parameters were similar in scales in the two groups. Alterations of the spinal curve accompanied by changes in the proportions, mechanical strength and mineral content of the vertebral bodies of the pinealectomized salmon indicate that melatonin has several functions related to vertebral bone growth. As the lesions found in salmon are similar to the spinal malformations observed in avian species and mammals after pinealectomy, this study strengthens the hypothesis of a phylogenetically conserved function of the pineal gland related to skeletal development.

Animals↗
PubMed2004

Patients' choice of dental treatment following examination at a specialty unit for adverse reactions to dental materials.

The Dental Biomaterials Adverse Reaction Unit in Bergen, Norway, is a national unit for the examination of patients with suspected adverse reactions to dental materials. The aim of this study was to investigate whether patients with suspected adverse reactions to dental materials experienced improvement in health after dental restorations had been replaced, and whether they had acted according to the recommendations of the Unit. A questionnaire was sent to 358 patients who had been examined at the Unit 18 months to 7 years earlier. Of the 207 patients who completed the questionnaire, 85 had had restorative materials replaced with other types of materials. A majority had had amalgam fillings replaced. After replacement, 51 patients reported an improvement in health. Twelve patients reported that they felt worse after replacement. The Unit recommended replacement of materials in 31 patients, of whom 24 followed the recommendation. Among 176 patients who were not given specific recommendations as to replacement of dental materials, 67 had had their restorations replaced, and 40 had started to have them replaced. It appears that the examination at the Dental Biomaterials Adverse Reaction Unit is one of several inputs that influence a person's decision to replace dental materials.

Adolescent↗
PubMed2004

Four years of clinical experience with an adverse reaction unit for dental biomaterials.

OBJECTIVES: We describe the function of, and results from, the Norwegian National Dental Biomaterials Adverse Reaction Unit after 4 years of activity from 1993 to 1997. METHODS: During this period of time, 296 patients were examined at the unit, which is located at the Dental School, University of Bergen. The most prevalent age group was 40-49 years, and 70% were women. Dental amalgam was the primary reason for referral to the unit for nearly 85% of the patients, followed by metals in crowns and bridges (11%). Materials in removable dentures, resin-based filling materials and cements, endodontic materials, and others, including temporary materials, were also involved. Nearly all (96%) patients reported general subjective symptoms, such as muscle and joint pain, fatigue, and memory problems. Complaints involving the orofacial region (lips, face, temporomandibular joint) and intraoral subjective symptoms were also common. RESULTS: Of the patients who were patch tested with substances in dental materials, 23% were positive to gold, 28% to nickel, 14% to cobalt, 9% to palladium, 6% to mercury, and 8% to one or more components of resin-based materials. Mercury concentrations in blood and urine were statistically higher in the patients with amalgam fillings compared with those without. CONCLUSIONS: Generally, we could not establish a straightforward cause-and-effect relationship between the presence of dental biomaterials and general symptoms. Twenty patients were advised to replace restorative materials because of contact lesions. Another 20 patients were recommended replacement of materials because of allergy verified with positive patch tests. The complex nature of most of the reactions requires a multidisciplinary approach to the care taking of patients who are concerned about reactions from dental materials, particularly amalgam.

Adult↗
PubMed2003

Reporting on adverse reactions to dental materials--intraoral observations at a clinical follow-up.

OBJECTIVES: A national reporting system designed to monitor adverse reactions to dental materials was established in Norway in 1993. The activities have also included clinical examination of patients with suspected reactions to dental materials. The ongoing activities are coordinated by the Dental Biomaterials Adverse Reaction Unit at the University of Bergen. The reporting procedure is based on voluntary spontaneous reporting by dentists and physicians. The reports could be based on subjective symptoms or objective findings, or both. The aim of the present study was to compare reported objective intraoral findings with those found during examination at the unit. METHODS: Reported reactions were compared with clinical findings obtained following dental and medical examination at the unit. From 1993 to 1999, a total of 899 reports were received while 253 patients were referred and examined at the unit. RESULTS: The reports on patients who were examined at the unit involved mainly reactions related to amalgam fillings (84%), metals in fixed dentures (11%), resin-based materials and cements (4%), materials used in removable dentures (2%), and endodontic materials (2%). Edema, lichenoid reactions, ulcers/vesicles, erythema, and atrophy were found in 80 patients during the examination at the unit. For 35 of these patients, the intraoral findings at the unit were also given in the reports. For another 45 patients, objective intraoral signs of reactions were found upon examination at the unit, but these findings had not been reported. CONCLUSION: A spontaneous reporting system is a cost-effective method for monitoring intraoral reactions associated with dental materials. Considering the increasing number and complexity of these materials, there appears to be a need for continuous validation of reports by a speciality unit. In order to receive more accurate information about the adverse reactions, it would be advisable that the reporting forms include more detailed guidance regarding signs of reactions that practitioners should be on the look out for and consider.

Adult↗
PubMed2003

Personality variables in patients with self-reported reactions to dental amalgam.

Personality variables in persons with self-reported reactions to dental amalgam (amalgam patients, n = 26, 17 F, 9 M) and in others without such symptoms (controls, n = 21, 14 F, 7 M) are compared. The groups were comparable regarding age, education, and amount of amalgam. Minnesota Multiphasic Personality Inventory-2 (MMPI-2) profiles were obtained for all subjects. On MMPI-2, the amalgam patients presented a 'conversion V' pattern, and elevated psychasthenia and schizophrenia scales, reflecting an increased prevalence of psychological and somatic complaints compared with the controls. This indicates that amalgam patients experience ill health, as their personality profiles bear several similarities with other groups with long-lasting symptoms.

Adult↗
PubMed2003

Copper, zinc, and selenium in human blood and urine after injection of sodium 2,3-dimercaptopropane-1-sulfonate: a study on subjects with dental amalgam.

This study investigated the effects of a single dose of intravenously administered sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) on the essential elements copper, zinc, and selenium in human blood and urine. The possible role of dental amalgam was also addressed. Eighty individuals, divided in four groups according to the presence or absence of dental amalgam fillings and symptoms self-related to such fillings, were given DMPS (2 mg/kg body wt) and 500 mL Ringer's acetate intravenously. Urine and blood were collected prior to the injection, and thereafter at intervals over a 24-h period. Cu, Zn, and Se concentrations were determined by atomic absorption spectrometry methods. A statistically significant increase in the concentrations of Cu and Zn in urine was observed 30 and 120 min after the DMPS injection compared to the preinjection concentrations. The concentrations of Se were not affected. The cumulated excretion over 24 h after DMPS injection constitutes only from 0.1% to 0.7% of the body content of these elements. There was no effect of different amalgam statuses on Cu and Zn excretion. We found a temporary decrease (4-7%) in the concentrations of Cu, Zn, and Se in blood 15 and 30 min after DMPS, but this seems to be the result of dilution factors. Administration of a single dose of DMPS does not affect the body stores of the essential elements Cu, Zn, and Se.

Adult↗
PubMed2002

[Removal of osteosynthetic implants].

BACKGROUND: Removals of fracture implants constitute a considerable share of orthopaedic operations and take up significant hospital resources. In the Norwegian basic fracture course, guidelines are given on indications for removal as well as minimum function time for implants. Indications for implant removal are, however, relative, and we wanted to study actual practice in this field in Norway. MATERIAL AND METHODS: An inquiry was made to Norwegian hospitals in spring 2000 concerning their current practice for implant removal. RESULTS: Most hospitals follow the suggestions given but there is still great variation, especially in age limits for routine removal of all implants, which range from 15 to 70 years. INTERPRETATION: Implant removal is desirable after fracture healing but it requires a surgical procedure with a certain morbidity and incidence of complications. Lack of strict criteria for removal may explain varying practice. We conclude that there should be a uniform practice for implant removal in Norwegian hospitals. More research is warranted on the possible systemic and local long-term effects of implants remaining in situ in order to give more evidence-based indications for implant removal.

Adolescent↗
PubMed2002

Dental amalgam affects urinary selenium excretion.

Selenium may have a protective effect against mercury toxicity. The aim of the present study was to investigate if selenium excretion in urine was affected in persons with dental amalgam fillings. The reason for this study is that dental amalgam is the most important source of inorganic mercury exposure in the general population, although the potential toxic effects of this exposure remain a subject for debate. The chelating agent 2,3 dimercaptopropane-1-sulfonate (DMPS) was injected intravenously (2 mg/kg) to provoke metal excretion. Urine samples were subsequently collected at intervals over a 24-h period. Selenium concentration was determined by hydride-generation atomic absorption spectrometry. The study was comprised of 20 persons who claimed symptoms from dental amalgam and 21 healthy persons with amalgam fillings. There were two control groups without amalgam. One control group had amalgam replaced because of concern about illness resulting from mercury release (n = 20), whereas the other control group never had amalgam (n = 19). Individuals with amalgam excreted less selenium (36.4 microg, median value) over 24 hours than those without amalgam (47.5 microg) (p = 0.016). There was no difference in selenium excretion between groups with (42.4 microg) and without (39.4 microg) amalgam-related symptoms (p = 0.15). The findings indicate that individuals exposed to low levels of elemental mercury from dental amalgam excrete less selenium to urine than unexposed individuals.

Case-Control Studies↗