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Biomedical subjects

H Nilson

Publications and source records attributed to H Nilson.

12 recordsLinked to original sources
PubMed1994

Dentacolor as veneering material for titanium. A clinical evaluation after 51-72 months.

Fifty-one patients who had been provided with 104 Dentacolor veneered titanium copings/pontics were recalled after periods varying between 51 and 72 months. Fourty-two patients with 85 units-67 crowns and 18 pontics-attended. In this retrospective study the condition of the veneering material was rated by dentists who had performed the treatment. Seven units exhibited Dentacolor fractures and one obvious discoloration of the veneering material. These eight units correspond to a failure rate of 9.4%. The corresponding failure rate after 3 years was 7.1%.

Adult↗
PubMed1990

Cross-sectional study of patients fitted with fixed partial dentures with special reference to the caries situation.

The caries situation among 30 patients with fixed partial dentures was examined 3 yr after cementation of the constructions. The fit of the crowns on the abutment teeth, the size of the interproximal areas and the relation between the crown margin and the gingival margin were registered. Risk factors for caries development, such as salivary factors, microbiologic factors, oral hygiene and diet were evaluated for each patient. During the 3-yr period 54 caries lesions occurred in 25 patients. Eleven lesions were found on abutment teeth. Two were located on the root surfaces unconnected with the crown margin (greater than 2mm from the gingival margin), three were recurrent lesions, where the crown margin was located above the gingival margin but closer than 2 mm and six were recurrent lesions where the crown margin was located under the gingival margin. No single caries risk factor seemed to be so closely correlated to the number of caries lesions developed that it could be used alone to select of patients at risk. When the sum of the assumed negative factors was used, more caries was found among the patients with three or more factors with negative values in the group as a whole. However, predicting the development of caries in an individual case with a high degree of probability seems to be complicated. Generally speaking there was no indication that caries disease development was caused by the presence of the fixed partial denture per se.

Adult↗
PubMed1990

A 2-year follow-up study of titanium crowns.

In 1986, 149 patients were provided with titanium crowns. The method used for fabrication of the titanium copings involved two principles: machine duplication of models and electric discharge machining. For the veneering of the copings, Isosit was used for the first 90% of the crowns in the series, and the Dentacolor-Silicoater technique for the last 10%. Of 205 individual crowns cemented in 1986, 167 could be examined after 2 years. The crowns were rated by four independent examiners using the CDA quality evaluation system. Bleeding Index and Margin Index were also used. The Margin Integrity score was recorded as satisfactory for all crowns examined over the period studied. A vast majority of the margins were rated as excellent. Isosit (n = 145) disclosed shortcomings including fractures and substantial deteriorations of Surface and Color and of Anatomic Form. With Dentacolor as veneering material (n = 18) the results with the factors Surface and Color and Anatomic Form were still rated satisfactory after 2 years, and no fractures of the veneering material were registered. Bleeding Index and Margin Index showed comparatively small changes after 2 years.

Acrylic Resins↗
PubMed1990

Osseointegrated implants in edentulous jaws: a 2-year longitudinal study.

Osseointegrated implants in 50 edentulous jaws were studied during a 2-year observation period. The implant survival rate was 89% in the maxillae and 97% in the mandibles. The marginal bone loss averaged 1.7 mm in the maxillae and 1.1 mm in the mandibles. Most of this bone loss occurred during the first year. The bone loss was greater in jaws with a preoperatively minor resorption of the alveolar ridge than in those with moderate or advanced resorption. The bone loss was also greater at the medially positioned implants than at those more posterior.

Adult↗
PubMed1990

Impression technique for RPDs. A comparison between two methods.

The purposes of this study were threefold, 1) to develop a method for comparing various impression techniques and materials, 2) to compare the extension of impressions with ZOE-paste and silicone, and 3) to evaluate the precision for each method. A special device was constructed in order to secure an identical position of the impression trays. The results indicated that ZOE-paste impression in a border moulded tray produced more extended impressions lingually but buccally there were no difference between the chosen materials/method. No differences in precision of the two methods could be measured.

Dental Impression Materials↗
PubMed1989

Clinical results with titanium crowns fabricated with machine duplication and spark erosion.

A new method for fabrication of metal crowns has been developed by one of the authors (M.A.). There are two principles involved: machine duplication of models and electric discharge machining. The metal used is pure unalloyed titanium, which is processed as a coping and later covered by a composite resin. In 1986, 205 separate titanium crowns were made on 149 patients. One year later 192 crowns on 137 patients could be examined. Five crowns had been replaced by new ones owing to fracture of the composite resin. In accordance with the CDA quality evaluation system the following results were obtained for the remaining 187 crowns: margin integrity, 186 excellent or satisfactory (99.5%); anatomic form, 185 excellent or satisfactory (98.9%); and surface and color, 181 excellent or satisfactory results (96.8%). The 1-year results are promising, and further follow-up studies will be made.

Acrylic Resins↗
PubMed1982

A clinical re-examination of patients treated with pinledge-crowns.

A group consisting of forty patients received a clinical and radiological re-examination, of a cross-sectional type, to examine the effects of pinledge-crowns on teeth and periodontal tissues. The mean age of the material, which consisted of patients treated at the Department of Prosthetics, University of Umeå, during the period February 1969-November 1971, was 48.6 years (18 male, 22 female). In these patients fifty-one pinledge-crowns had been inserted, in 88% of the cases on a canine tooth. In every person, the contralateral tooth served as a control tooth. The teeth were examined with regard to the frequency of failure (expressed as failure rate %/year), the presence of caries, and the periodontal status. The results showed that of the total number of pinledge-crowns (fifty-one), twelve had been removed before the time of examination. At the examination it was found that one crown had extensive caries, which required a revision of the crown, and one tooth had a non-sensitive pulp with a periapical osteitis. These fourteen (27.5%) pinledge-crowns were classified as failures. The value of the failure rate expressed as %/year was, after 8 years, 3.43 pinledge/year or 3.13, if the patient was used as a unit. Concerning the periodontal effects, the difference between teeth fitted with pinledge-crowns and control teeth was small.

Adult↗
PubMedDate not supplied

MkII--a modified self-tapping Brånemark implant: 3-year results of a controlled prospective pilot study.

A modified self-tapping implant (MkII) with improved cutting characteristics has been designed for use in both maxillae and mandibles. Four sequential studies were conducted to evaluate the outcome of the MkII implant compared to the standard implant. The results presented here are from the extended pilot study that has been conducted as an intra-individual study of 103 patients; ie, each patient received both test (MkII) and control (standard Brånemark System) implants. Seventy patients were treated in the mandible and 33 in the maxilla. The cumulative survival rates and marginal bone resorption showed equivalent results for both test and control implants. Three-year cumulative survival rates were 87.9% and 86.8% for test and control implants in maxilla, respectively, and 99.5% and 100% in mandibles, respectively. The mean marginal bone resorption was approximately 0.5 (control) to (MK II) 0.6 mm after 3 years of function. A total of 288 test implants and 275 control implants were placed. All implants, both test and control, could be placed in an appropriate implant position, but 21.2% of the implants were not fully seated by machine power only; the use of a manual cylinder wrench for the final turns was necessary. During the last phase of the study, however, with an increase in twist-drill diameter from 3.0 to 3.15 mm and an increased motor torque, the prerequisites of successful implant placement into final position were met.

Adult↗
PubMedDate not supplied

Titanium copings veneered with Procera ceramics: a longitudinal clinical study.

In 1989, 47 titanium copings veneered with a low-fusing ceramic were fabricated for 24 patients. Forty-four crowns could be examined after a period varying between 26 and 30 months. It was found that the bulk ceramic of two crowns had fractured. California Dental Association ratings for "Surface and Color" had changed markedly from the "Excellent" to the "Acceptable" level, and for "Anatomic Form" there was a small shift from the "Excellent" to the "Acceptable" level. The factor of "Margin Integrity" was recorded as "satisfactory" for all crowns and a large majority were rated "Excellent."

Adult↗