MELISA-an in vitro tool for the study of metal allergy.

The sensitizing properties of metals widely used in medical and dental care have been studied with the help of an optimized lymphocyte proliferative assay, MELISA. MELISA (memory lymphocyte immuno-stimulation assay) was originally developed for the screening of allergenic epitopes of drugs and other chemicals of low molecular weight, but has recently been adapted for the study of metal-induced sensitization. The patients studied suffered from various oral mucosal problems which were suspected to be caused by the release of metal ions from dental restorations. They were also troubled by chronic fatigue persisting over many years. One patient was also occupationally exposed to metals while working in a dental practice. Healthy subjects without any discomfort due to metal devices served as controls. In addition to metals used in dentistry, lymphocyte responses to organic mercurials used widely as preservatives in vaccines, eye/nose drops and contact lense fluids were studied. The results indicated that mercurials, as well as other metals such as gold or palladium, induce strong lymphocyte proliferative responses in patients with oral or systemic symptoms, but not in similarly exposed unaffected subjects. The results of MELISA performed with a pair of identical twins with chronic fatigue syndrome (CFS) indicated that metal-specific responses may be dependent on the genetics of the patient. Thus, many metals that are today accepted for use in medicine and dentistry carry a definite sensitizing risk for certain genetically predisposed individuals. Therefore, the use of these metals should be limited in the future.

Single-tooth restorations supported by osseointegrated implants: results and experiences from a prospective study after 2 to 3 years.

Fifty-seven patients were followed for 2 years and 34 patients for 3 years in a study of the CeraOne system. One implant was lost, resulting in a cumulative success rate of 97.3% at the 3-year examination. All-ceramic crowns were seated for 95% of the subjects, and only four of the crowns were classified as failures. Two all-ceramic crowns fractured following trauma, but no crown was fractured when exposed to common bite forces. The bone loss around implants and adjacent teeth was small, and few problems were observed. It was proven that the system achieves good esthetic results and avoids the complications of screw loosening and fistula formation.

Rehabilitation of patients with severely resorbed maxillae by means of implants with or without bone grafts. A 1-year follow-up study.

Forty-three patients with severely resorbed maxillae who had been referred for implant treatment were assigned to one of three treatment groups: bone grafting and implant placement (graft group); modified implant placement but no bone grafting (trial group); or optimized complete dentures (no-implant group). Sixteen, 20, and 7 patients, respectively, were assigned to the three groups. At the 1-year follow-up, 10% of the implants had been lost. Only a few of the failures (3/22) occurred after prosthesis placement. The cumulative success rates were 83% in the graft group and 96% in the trial group. A substantial reduction of the grafted bone, especially of the onlay grafts, occurred in many patients. During the period from prosthesis connection to the 1-year follow-up, marginal peri-implant bone loss was on average 0.5 mm. Despite the often demanding procedures involved, all but one patient in each implant group said that they would undergo the treatment again. Most patients were very satisfied with the treatment outcome and their improved masticatory ability. Those who had renounced implant treatment appeared modestly adapted to their optimized dentures, but reported retention problems and less satisfaction with mastication.

Rehabilitation of patients with severely resorbed maxillae by means of implants with or without bone grafts: a 3- to 5-year follow-up clinical report.

Forty three patients with severely resorbed maxillae who had been referred for implant treatment were assigned to 1 of 3 treatment options: bone grafting and implant placement (graft group), modified implant placement with no bone grafting (trial group), or optimized complete dentures (no-implant group). Sixteen, 20, and 7 patients, respectively, were assigned to the 3 groups. The patients have been examined annually, and at the time of this report they had been followed for 3 to 5 years after treatment. At the 1-year follow-up, 10% (22 of 221) of the implants had been lost, and at the 2-year follow-up, 18% of the implants had been lost (40 of 221; 25% in the graft and 13% in the trial group); after that time, no further losses occurred. Life table analysis showed cumulative success rates of 82% in the graft group and 96% in the trial group after 1 year, and 74% and 87%, respectively, at the final examination after 3 to 5 years. The failure rate was higher in smokers than in non-smokers. A substantial reduction of the grafted bone, especially of onlay grafts, occurred early after grafting surgery in many patients. Mean marginal peri-implant bone loss was 0.6 mm during the period from prosthesis connection to the 1-year follow-up, and from the 1-year to the 3-year follow-up, average peri-implant bone loss was 0.3 mm in the graft group and 0.5 mm in the trial group. The results corroborated previous findings that patients with severely resorbed maxillae have an increased risk of implant failure in comparison to patients with good bone quantity and quality. However, in this investigation, practically all implant losses occurred during the first 2 years, whereupon a steady state seemed to follow for up to 5 years after loading.

Effect on caries and gingivitis of a preventive program based on oral hygiene measures and fluoride application.

The present investigation was performed to estimate the effect on caries and gingivitis of a plaque control program delivered at different intervals and supplemented with different fluoride compounds. The study ran for 2 years and was completed by 260 children who were 13-14 years old at the beginning. Professional tooth cleaning in combination with detailed oral hygiene instructions repeated once a month or every 3 months significantly improved their oral hygiene status and reduced clinical signs of gingivitis. The addition of fluoride (NaF or MFP) in mouthrinses and toothpastes significantly reduced the number of new carious lesions. No significant differences were observed in gingival health and caries activity between the programs delivered once a month and every 3 months.

Follow-up study of recurrent parotitis in children.

Recurrent parotitis in children is a well-described but rare condition of unknown cause. In this follow-up investigation the long-term course of the disease was studied both clinically and radiographically. In 23 of 25 patients investigated, the clinical symptoms disappeared before the patients were 22 years of age, independent of a given therapy. However, sialographic changes, mostly in the form of sialectasis, were seen on follow-up in the majority of cases, in spite of the fact that the patients were clinically symptom free.

Marginal tissue reactions at osseointegrated titanium fixtures. (II) A cross-sectional retrospective study.

20 totally edentulous patients, provided with 24 facultatively removable fixed bridges (13 upper and 11 lower jaws) were recalled. The material consisted of 125 osseointegrated titanium fixtures with a mean observation time of 7.6 years (range 6 months to 15 years). The marginal tissues were examined by conventional periodontal clinical methods and standardised radiography. Microbiological samples and biopsies of the soft marginal barrier tissues were retrieved for dark-field and histological analysis, respectively. The percental ratios of abutment surfaces devoid of plaque and without signs of gingivitis, were 46% and 20%, respectively. In contrast to earlier studies, the presence of plaque and gingivitis was significantly correlated. This relationship was probably due to more plaque being present. The mean probing depth was 3.8 mm. In 40% of the measurements, the probing depths were 3 mm or less, and in 45% between 4 and 5 mm, whereas they only in 15% were 6 mm or more. They were greater in upper than in lower jaws and were found to be significantly correlated with gingivitis. Attached gingiva surrounded about 51% of the buccal and lingual abutment surfaces. The marginal bone height changes were very small during the follow-up period (0.07 mm annually). Coccoid cells and non-motile rods dominated the microflora to 94% in the 48 samples taken. Out of the 19 biopsies, 58% showed healthy mucosa and a further 37% had the lowest inflammation score. The indications of gingivitis and deep pockets at the clinical examination were not found accompanied by an accelerated marginal bone loss, nor by a microflora or histological changes indicative of periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Diskectomy in temporomandibular joints with internal derangement: a follow-up study.

OBJECTIVE: To follow up a series of patients treated consecutively who had undergone a diskectomy 2 years previously because of persistent pain and disk displacement in the temporomandibular joint. STUDY DESIGN: Sixteen subjects rated their current symptoms during 1 week and were systematically examined for signs of temporomandibular disorders clinically and radiographically by independent observers. RESULTS: Subjectively, all subjects were satisfied with the operation. Five rated their current pain as significant during masticatory function. Some signs of temporomandibular disorders, usually related to function, were registered in all subjects. Postoperative mandibular movements were improved but still below normal range. Signs and symptoms correlated significantly. Surgical complications were nonexistent, but radiographic changes were extensive. Erosion and flattening of the condyle were common. CONCLUSIONS: It was verified that subjects with persistent pain and disk displacement benefit subjectively and clinically from diskectomy. The radiographic outcomes appear less encouraging. Only prospective, randomized, and controlled studies can eventually clarify the effectiveness of diskectomy in relieving pain caused by displacements in the temporomandibular joint.

Differences in caries recording with and without bitewing radiographs. A study on 5-year old children in the County of Bohuslän, Sweden.

In Sweden, when caries prevalence was much higher, bitewing radiographs (bwg's) were taken on all school children at their annual examination. It has been argued that bwg's should also be taken on 4- to 6-year-olds, with approximal surfaces in the molar area in contact (Stecksén-Blicks & Wahlin 1983). However, discussion about radiation-risk in combination with low caries prevalence seem to have made Swedish dentists reluctant to take radiographs on pre-school children. The aim of this study was to find out if there was a difference in caries recording when information from bwg's was added to that from clinical examination. Therefore 180 5-year-old children were randomly selected to constitute a test group examined both by the dentists who see the patients at the annual examination and do not use bwg's and by two of the authors, who had access to bwg's. No statistically significant difference in carries prevalence was noted from the registrations made by the clinicians and the authors when bwg's were not used (x = 1.8 versus 2.0). When the authors had access to bwg's they considered 1.8 more surfaces to be carious compared to when bwg's were not used (x = 3.8 versus 2.0). Of these, 1.0 surfaces were open lesions and 0.8 were incipient lesions. The difference was statistically significant (p < 0.001) as tested by paired t-test. Extreme differences were noted in single cases. It was concluded that clinical examination only, underestimates the correct caries status.

Marginal tissue reactions at osseointegrated titanium fixtures.

A longitudinal prospective and a cross-sectional retrospective study were undertaken in order to investigate the marginal tissue reactions at osseointegrated titanium fixtures and their abutments, supporting fixed bridges. Conventional clinical periodontal examination methods were combined with a serial-identical radiography. At the termination of the studies samples were taken for microbiological and histological analyses. Altogether the reactions at 220 fixtures in 40 jaws were explored. The clinical parameters were not found correlated with the other examination methods. Only 0.9 mm marginal bone was lost as a mean during the first year and then not more than 0.05-0.07 mm as a mean annually for the follow-up years. A stress-related remodelling of the perifixtural bone was observed radiographically. The microbiotia in the gingival pockets was dominated by cocci and non-motile rods (94%), indicating a favourable composition if similar findings had been observed at teeth. Half the number of the biopsies had no inflammatory infiltrates and a further third had the lowest inflammatory score in a 3-grade scale. The results indicate that the soft tissue surrounding the gingival part of osseointegrated fixtures remains remarkably healthy, which, in combination with the annual minor loss of marginal bone, is an indication of good long-term clinical prognosis.

The salivary gland component of Sjögren's syndrome: an evaluation of diagnostic methods.

The diagnostic value of sialography, scintigraphy, sialometry, and labial salivary gland biopsy--as indicators of salivary gland dysfunction in Sjögren's syndrome (SS)--was evaluated in 41 patients suspected of having SS. In about 70% of the cases, each of the four examinations showed changes that could indicate a salivary gland component of SS. However, the disease specificity of sialographic and scintigraphic examinations was low. Although the specificity of the labial salivary gland biopsy examination is considered high, our study revealed some cases in which a focus score of 1 to 3 was not accompanied by abnormal changes in either sialometry, sialography, or scintigraphy. At a focus score of more than 3, a fair amount of agreement on the results of the various diagnostic procedures was found. Because labial salivary gland examination shows only minor salivary glands and sialography and scintigraphy include only major salivary glands, variance between different diagnostic procedures is expected. This indicates a potential diagnostic role for sialographic and scintigraphic examination when the labial salivary gland biopsy is insufficient.

Selenium protection against toxicity from cadmium and mercury studied at the cellular level.

Interaction between selenium and the heavy metals cadmium and mercury was studied in an experimental rat model (Sprague-Dawley). The rats were administered either one single trace element or combinations of selenium and cadmium as well as selenium and mercury. Salts of these trace elements were administered intraperitoneally daily during thirty days. Thereafter the animals were sacrificed and kidneys and livers excised rapidly. Thin sections were produced by a cryotome and subsequently freeze-dried. Nuclear microscopy of the sections showed that in the combination groups there was a co-localization of selenium and the heavy metals. None of the expected pathological signs of cadmium and mercury toxicity were observed. The conclusion was that selenium exerted a protective effect against the toxicity of cadmium and mercury through mechanisms still to be unveiled.

Assessment of temporomandibular joint disease by panoramic radiography: reliability and validity in relation to tomography.

OBJECTIVES: To assess the reliability and validity of panoramic radiography for TMJ evaluation in comparison with tomography. METHODS: One TMD specialist assessed the panoramic radiographs of 50 TMD patients and 20 non-TMD subjects on two occasions. A third evaluation was made after calibration with an oral radiologist who also assessed the radiographs twice and the patients' corresponding tomograms. Each TMJ was assessed for five features. RESULTS: Absence of TMJ disease varied between 56 and 87% for the different features and the two observers on the panoramic radiographs. Condylar flattening was the most frequent positive finding. Mean intra-observer agreement varied between 0.34 and 0.79. Mean inter-observer agreement varied between 0.22 and 0.65 and increased after calibration. Agreement was worse for the temporal component. Pathological findings were more frequent on the tomograms and varied between 6 and 19%. Mean sensitivity varied between 0.00 and 0.60 and mean specificity between 0.59 and 0.95. Mean PPV ranged from 0.25 to 0.90 and NPV from 0.02 to 0.22. CONCLUSIONS: Evaluation of bony changes on the condyles has acceptable reliability and specificity but low sensitivity, whereas the temporal component has low reliability and accuracy. Positive findings often correspond to disease while negative findings do not exclude it. If bony abnormality is suspected in the TMJ, and the panoramic radiograph is negative, tomography may be indicated.

Management of chronic orofacial pain: attitudes among patients and dentists in a Swedish county.

The purpose was to survey attitudes towards management of chronic orofacial pain (COP). Questionnaires were mailed to 30 randomized dentists and to 30 consecutive COP patients, examined 16 months earlier by a pain group of dental specialists. Fifty-seven per cent of the patients reported that their pain was the same as or worse than before and was disturbing. Few were dissatisfied with the examinations. Fifty-nine per cent thought that the consultations had been good. The surveyed dentists judged the most common causes of COP to be neurogenic and psychogenic in origin; they were overwhelmingly positive to the idea of a pain group (93%) and could consider referring patients (97%). Pain-inducing local diseases occurred but were not dominant among these COP patients. We concluded that management of COP in a pain group appears to be meaningful, as reflected by the respondents' attitudes but would gain by a closer collaboration with medical expertise.

A comparison of a new dental X-ray film, Agfa Gevaert Dentus M4, with Kodak Ektaspeed and Ultraspeed dental X-ray films.

A new dental X-ray film, Agfa Gevaert Dentus M4, has recently been introduced. Its diagnostic ability for approximal caries and its sensitometric properties were compared with those of Kodak Ultraspeed and Ektaspeed dental X-ray films. Seven general practitioners and six consultants in oral radiology recorded both incipient and manifest approximal caries on radiographs of 100 extracted premolars. ROC-curve technique was used to analyse the results. A significant difference in diagnostic accuracy for both incipient and manifest caries was found between Ektaspeed and Dentus M4, but not between Ektaspeed and Ultraspeed or between Ultraspeed and Dentus M4. Ektaspeed had the highest diagnostic accuracy, 0.79, while Dentus M4 had the lowest, 0.72. No significant differences were found between the different films in their ability to separate sound from cavitated surfaces. The speed and contrast of the three dental X-ray films were measured according to ISO 3665. Dentus M4 film was found to be 1.8 times faster than Ektaspeed and 2.8 times faster than Ultraspeed. Dentus M4 had a lower film contrast than both Ultraspeed and Ektaspeed. Films of the three different types and with about the same expiry date were stored in seven different clinics. One film of each type was developed each month over a 16-month period under standardized conditions. Base plus fog density was measured. The Dentus M4 had a more rapid build up of fog compared to Ultraspeed and Ektaspeed films. We conclude that the new Dentus M4 film has a limited value in the diagnosis of incipient caries.

Metal exposure from amalgam alters the distribution of trace elements in blood cells and plasma.

Twenty-seven consecutive patients with health problems associated with dental amalgam were recruited. In spite of thorough medical examinations, there were no diagnoses available. The patient group was dominated by women. A healthy age- and sex-matched control group with dental amalgams without symptoms was also recruited. Metal level monitoring in plasma and nuclear microscopy of isolated individual blood cells were carried out. Significant increases of copper, iron, zinc and strontium were found in patient plasma. There was no significant difference in plasma selenium between the groups. Mercury was significantly increased in patient plasma, although there was overlap between the groups. In erythrocytes a significant increase in calcium and a significant decrease in magnesium, copper, manganese and zinc were found. Calcium, magnesium, manganese and copper increased in patient neutrophil granulocytes. A significant decrease was found for zinc. A conspicuous finding was the presence of measurable mercury in a few of the cells from the patient but not in the control group. Thus, nuclear microscopy of isolated individual blood cells might provide a better diagnostic tool for metal exposure than blood plasma measurements.

Temporomandibular joint involvement in systemic lupus erythematosus.

Temporomandibular joint involvement was studied in 37 systemic lupus erythematosus patients not selected with regard to this involvement. One-third had current complaints and two-thirds had a history of severe symptoms. Objective findings indicating systemic lupus erythematosus arthritis were locking or dislocation, tenderness to palpation, and pain on movement of the mandible. Such changes were found in 8 patients (22%) but in none of the healthy controls. Radiographic changes of the condyles, including flattenings, erosions, osteophytes, and sclerosis, were seen in 11 patients (30%), 4 of whom had deformity of other joints as well.

Influence of film fog on radiographic caries diagnosis.

Increasing film speed may potentially jeopardize diagnostic quality because of a more rapid build up of fog and an ensuing decrease in image contrast. A standardized amount of fog was simulated by pre-exposing E-speed dental films before use to obtain images of extracted teeth with and without approximal caries. Three experiments were performed. In the first, no effort was made to compensate for the increased density caused by fog. In the other two, density was kept constant by reducing exposure and developing time respectively. Nine dentists recorded the presence and absence of caries using a rating scale to indicate diagnostic confidence. As a measure of diagnostic accuracy, the area under the binormal ROC curve was used and the values averaged across observers. The results showed that fog, up to a level of base plus fog of 0.6 optical density units, had no influence on the diagnostic accuracy in the absence of any compensation. When exposure was lowered to compensate for the increased density, significantly lower diagnostic accuracy was found. On the other hand, when developing time was decreased, no significant difference was found. Observers ranked radiographs with higher levels of fog as being of lower quality. However, no significant correlation was found between subjective ranking of image quality and diagnostic accuracy obtained from the same radiographs. It is concluded that relatively high levels of fog do not exert a negative influence on approximal caries diagnosis and no attempt should therefore be made to compensate for the increased density.

Surgical and prosthodontic training of general practitioners for single tooth implants: a study of treatments performed at four general practitioners' offices and at a specialist clinic after 2 years.

Both the surgical and the prosthodontic procedures will be performed by one and the same general practitioner (GP) for many implant patients, as access to specialists is limited or non-existent in a large number of places. However, treatment by GPs has not been documented to the same extent as treatment performed by specialists. This lack of knowledge was the reason for the present study, in which four GPs performed both the surgery and the prosthodontics on patients requiring single tooth implant replacements. The treatments were performed after an initial training of the GP and his/her dental assistant for 8 days. The treatments by the GPs exhibited clinical results corresponding to those achieved at a specialist clinic. The outcome indicates that complete single tooth implant treatments might be performed by GPs who have passed an initial training and demonstrated an interest in a close co-operation with specialists in oral surgery/periodontics and prosthodontics. Such a co-operation should be based on the distribution of complicated cases to the specialists and of non-complicated cases to the GPs.