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Biomedical subjects

E Yontchev

Publications and source records attributed to E Yontchev.

At least 19 recordsLinked to original sources
PubMed1998

Use of titanium dental implants as an integrated part of a CLP protocol.

The problem of edentulousness in the cleft area of patients with cleft lip and palate was formerly resolved with a conventional fixed bridge construction, but this approach did not always prove optimal. Nowadays, in these patients the bridge can be substituted by a crown on an osseointegrated titanium implant fixture. The concept of dental rehabilitation using titanium implants has gradually merged into our routine treatment for patients with cleft lip and palate. In this report we describe our surgical technique using osseointegrated titanium implants and evaluate our result in patients with cleft lip and palate. Sixteen patients with cleft lip and palate, 11 men and five women, were divided into two groups: group 1 consisted of six patients who did not need bone grafting prior to the fixture installation, and group 2 comprised 10 patients who had additional bone grafting three months before the fixture installation. Abutments were applied six months after fixture installation. Dental crowns and fixed bridges were then constructed. All patients were seen on regular follow-up visits. Routine roentgenograms were obtained preoperatively and when the abutments were applied. Photographs were taken at these occasions and also after the prosthodontic work was completed. Of a total of 31 fixtures, all except two were osseointegrated at the time of the abutment connection, and the remaining 29 have all been functional during the observation period, giving a success rate of 93%. In group 1 all fixtures (100%) were osseointegrated. The non-integrated fixtures were found in group 2 giving a success rate of 91% in this group. The mean follow-up time after fixture installation was six years and three months, and the mean observation time with loaded fixtures was five years and six months.

Adolescent↗
PubMed1997

Potential side effects of dental amalgam restorations. (I). An oral and medical investigation.

The aim of this study was to explore a possible association between health status and self-reported adverse effects related to dental amalgam restorations. A group of 50 consecutive patients (index group), referred for complaints self-related to dental amalgam restorations, was compared with a control group of individuals matched by age, sex and postal zip code. The patients underwent an oral, stomatognathic, medical and clinical chemistry examination. Mercury levels were examined in blood, urine and hair. The results revealed that somatic diseases were more common in the index group (38% versus 6%). Symptoms related to cranio-mandibular dysfunction were reported by 74% of the patients in the index group versus 24% in the control group, and were diagnosed in 62% and 36%, respectively. The oral health status and the number of amalgam surfaces were similar in the 2 groups. No positive skin patch test to mercury was found in any of the groups. The estimated mercury intake from fish consumption, occupational exposure, and mercury levels in blood and urine were also similar and far below levels, where negative health effects would be expected. The correlation between the number of amalgam surfaces and mercury levels in plasma and urine (r=0.43) indicated a release of mercury from dental amalgam restorations in both groups. Since the mercury levels were similar among index patients and controls, mercury was not a likely cause of the impaired health reported by the patients.

Adult↗
PubMed1996

Long-term observations of extensive fixed partial dentures on mandibular canine teeth.

Twelve patients were followed for 15 years after treatment with a 12-unit cantilever fixed partial denture on the mandibular canines opposite to a complete maxillary denture. Four constructions failed and had to be removed but four were still in function after 15 years. Four patients died during the observation period still wearing their constructions. Endodontic complications, pulpal necrosis and loss of retention of posts were the most frequent, while caries and periodontal lesions were rare. The maintenance costs over the years were fairly low even compared to maintenance costs for patients treated with implants. Extensive mandibular cantilever fixed partial dentures may be used in the rehabilitation of patients with a very reduced dentition and a history of difficulties adapting to removable dentures.

Adult↗
PubMed1994

Masticatory function in patients with congenital and acquired maxillofacial defects.

Ninety-eight patients who received prosthodontic treatment for maxillofacial defects were examined clinically and by means of questionnaires and registration of chewing efficiency and occlusal force. Although 30% of the patients stated that they could chew soft food, and one third could not chew the test food (almonds), only 14% said they had a poor chewing ability. The mean occlusal force was small (80 N) but the individual variation was great (median 49 N, maximum 327 N). Despite major defects and poor functional test results, most patients were remarkably well-adapted to their situation and to maxillofacial prosthodontic rehabilitation. Severe signs and symptoms of temporomandibular disorders were rare.

Adolescent↗
PubMed1992

Masticatory function in patients with extensive fixed cantilever prostheses.

Eleven patients with complete maxillary dentures and 12-unit fixed partial dentures that included the mandibular canines were studied before and during specific intervals after prosthodontic treatment. Established methods for evaluation of oral function were used and the last examination was performed 30 months after treatment. All patients reported that their masticatory function had been substantially improved and there were no symptoms of dysfunction in the masticatory system. Masticatory efficiency improved after the prosthodontic treatment because both the number of cycles before the initial swallow and the total number of strokes including the time for completed mastication diminished after treatment. The occlusal force elevated after the prosthodontic treatment. Although great individual variations were recorded for all occasions and force levels, forces recorded on the extensions of the cantilever were similar to those on the canine regions.

Bite Force↗
PubMed1992

Long-term follow-up of patients with orofacial discomfort complaints.

To a group of 113 patients who exhibited wide variation in orofacial and general complaints, which they related to the effects of dental material, a new questionnaire was sent 8-10 years after the first examination. Eight patients had died, and 23 individuals could not be contacted. Of the remaining 82 patients, 62 (76%) individuals completed the questionnaire. Almost two-thirds (29%) of the responding patients reported that they were now free from the previous symptoms, or that these symptoms were alleviated (35%). Dryness of the mouth and smarting tongue were the most frequent symptoms at the follow-up. Half of the patients (52%) thought they still needed treatment for their complaints, and several of them had visited many other therapists after the end of the treatment period at the Department. The treatment outcome and symptom development may be regarded as acceptable with regard to the severity and long duration of the original complaints. However, the prognosis was poor in a substantial proportion of the patients, and this group continued to be a high consumer of health-care resources.

Burning Mouth Syndrome↗
PubMed1991

Orofacial functions in patients with congenital and acquired maxillary defects: a fluoroscopic study.

By means of videofluoroscopic recordings, chewing, swallowing and speech were monitored in nine patients with congenital and acquired maxillary defects. All of them were rehabilitated with a maxillary obturator prosthesis. The defective region was seldom used for chewing. No leakage between the obturator and surrounding tissue was observed, either for solids or for liquids. All of the prosthetic reconstructions were surprisingly stable during function. In the phonetic analysis, speech production was judged to be restored almost to normal. Videofluoroscopy may be valuable as a complement to other functional diagnostic procedures, and for the evaluation and improvement of rehabilitation with an obturator prosthesis.

Adult↗
PubMed1989

Dietary pattern, energy and nutrient intake in patients with oro-facial discomfort complaints.

In ninety-six patients with oro-facial and general complaints, which the patients assumed were caused by galvanic currents and/or metallic restorations, the recording and analysis of dietary pattern, energy and nutrient intake were performed. The records, in household measures, of the intake of food and beverages during 7 consecutive days according to a written instruction were collected. Sixty-eight out of the ninety-six records were sufficiently complete for calculation of nutrient intake. The remaining twenty-eight could only be used partially in the analyses. Most of the patients had a varied food intake of all the food groups during the 7-day period. The range was wide, however, and a few patients had relatively low intake of essential nutrients. It was not possible to find any correlation between oro-facial discomfort complaints and intake of any single nutrient that could indicate a cause-effect relationship. No correlation between diet pattern, energy and essential nutrients, and the measured electrode potentials of the fillings and constructions could be proved. Nor could the hypothesis that beverage intake might influence the electrode potentials and increase or aggravate the oro-facial complaints be verified.

Dentures↗
PubMed1989

Cinefluoroscopic study of long-term changes of bolus position and chewing cycle duration after fixed prosthetic treatment.

Some chewing parameters were studied in 12 patients with a complete maxillary denture and a 12-unit fixed mandibular denture anchored to the two canines. Registration by means of fluoroscopy were made before, 1 month after, and in four patients 13 yr after treatment. The mean velocity of the mandible during chewing increased after the prosthetic treatment and remained stable for meat during the observation period. At the first registration, before treatment, the bolus was most frequently located in the anterior region. After completion of the prosthetic rehabilitation, the bolus was mainly located to the lateral segments during chewing of the test foods, namely meat and bread. The recordings were almost identical 13 yr later. Despite a very reduced periodontal support, posterior cantilevered segments were satisfactorily used in comminution and the patients seemed to be unaware of the forces exerted on the remaining teeth.

Adult↗
PubMed1987

Clinical findings in patients with orofacial discomfort complaints.

In 113 patients with orofacial and general complaints, which they assumed were caused by galvanic currents and/or metallic restorations, clinical dental and medical examinations were performed. Most of the patients had natural teeth with dental metallic restorations. A number of dental diagnoses, such as caries, pulpitis, periapical osteitis and periodontitis, were found. However, 16% were edentulous in one or both jaws and had complete dentures. 69% had possible metal contacts. Some oral mucosal changes were observed, but they were as frequent in patients without as in those with metal contact possibility. Signs of parafunctions and functional disturbances of the masticatory system were extremely frequent. A careful oral examination in these patients thus revealed many clinical dental and oral signs that could be more-or-less related to the complaints. Because of the extremely varying symptoms reported, however, only a small proportion could be fully explained by odontological and/or medical diagnoses, and in 38% of the patients, no clear odontological diagnosis was found that could explain the complaints.

Adult↗
PubMed1987

Outcome of treatment of patients with orofacial discomfort complaints.

In 113 patients with a wide variation of orofacial and general complaints, which they assumed were caused by galvanic currents and/or metallic restorations, the initial and long-term development (3 years) after treatment was studied. Many treatment procedures were tried; besides information and follow-ups, each patient underwent in average of 6.6 different measures. The often time-consuming treatment was individualized, based on each patient's signs and symptoms. Besides conventional dental treatment, stomatognathic therapy and medical treatment which were frequently needed, metallic constructions were removed in 54% of the patients. The initial outcome of treatment was evaluated as successful both by patients and therapists in about 80%, but half of the patients reported recurrences, more often after removal of metallic constructions than after other dental treatment, while the dentists found recurring clinical signs in only 13% of the patients and without correlation to type of treatment. It is concluded that these patients need a careful oral examination and dental treatment of observed local pathology and defects of dental constructions, but removal of metallic constructions should be avoided when not indicated. Many of these patients will also need medical consultation and treatment, and a collaboration between the dentist and the physician is then recommended.

Combined Modality Therapy↗
PubMed1986

Reported symptoms, diseases, and medication of patients with orofacial discomfort complaints.

This paper is a part of a series of studies of 113 patients with orofacial and general complaints which they assumed were caused by metallic dental restorations and/or oral galvanic currents. An extensive case history was taken by means of a questionnaire and an interview. The results showed that the patients reported widely varying symptoms, both oral and general, such that the polysymptomatic character of the patients cannot be explained by a single etiologic factor. It is probable that many general factors, besides oral findings, alone or in combination, e.g. general health problems, side effects of medication, psycho-social problems including stressful life events, and complications due to the chronicity of pain, may be associated with the oral and general complaints of these patients.

Adult↗
PubMed1986

Contact allergy to dental materials in patients with orofacial complaints.

Two groups of individuals were patch tested for frequencies of contact allergy to dental materials. The patient group with orofacial and distant symptoms and complaints referred to the Department of Prosthetic Dentistry were compared with an age-sex matched control group of individuals referred to the Department of Dermatology. The results did not show any differences in patch test reactions between the patient and control groups. The study did not prove any obvious associations between the patients' symptoms or objective findings and the patch test results.

Adult↗
PubMed1986

An examination of the surface corrosion state of dental fillings and constructions. I. A laboratory investigation of the corrosion behaviour of dental alloys in natural saliva and saline solutions.

Electrochemical measurements on amalgams and gold alloys in natural saliva and saline solutions have been performed. The results show strong inhibiting effects of some components in natural saliva on the surface corrosion behaviour of amalgams. For the gold alloys the cathodic reduction of oxygen was notably lower in natural saliva than in saline solutions. For galvanic combinations of gold and amalgams substantially lower currents than those calculated from thermodynamic data can be expected in natural saliva.

Corrosion↗
PubMed1986

An examination of the surface corrosion state of dental fillings and constructions. II. A clinical study on patients with orofacial complaints.

A group of 115 patients with orofacial complaints has been examined. A new method for intraoral measurement of electrode potentials on the surface of the amalgam fillings and prosthetic constructions has been developed and applied. The possible connections between the measured electrode potentials and patients' saliva properties and their complaints have been discussed. No correlations between measured electrode potentials of the metallic fillings and constructions and important saliva properties could be found. No connections between the measured electrode potentials and the patients' complaints could be proved.

Adult↗
PubMed1986

Salivary and microbial conditions in patients with orofacial discomfort complaints.

Secretion rate, pH, and buffer capacity of paraffin-stimulated saliva and the prevalence of salivary Streptococcus mutans and lactobacilli were examined in 98 consecutive patients (22 men, 76 women) referred for orofacial discomfort complaints related to 'oral galvanism'. The results of this investigation were compared with those of a group of 100 patients without symptoms and complaints. The patients with orofacial symptoms and complaints had significantly fewer teeth with amalgam fillings than patients without, despite equal mean number of teeth in the two groups. Most patients had normal secretion rate and pH of saliva but somewhat low values of salivary buffer capacity. Determination of saliva conductivity showed values within a normal reference interval but lower than those from a group of subjects without orofacial symptoms and complaints. The salivary levels of cariogenic bacteria were low.

Adult↗