Agnar Halse

Incomplete healing (scar tissue) after periapical surgery—radiographic findings 8 to 12 years after treatment

Twenty-four cases treated by periapical surgery--which 2 to 6 yr after surgery were classified radiographically as incomplete healings (scar tissue)--were further followed, extending the observation period to 8 to 12 yr. One case healed completely, 1 failed, and 22 were still recorded in the same healing group. All the 22 scar tissue cases were characterized by a reduction of the defect in bone. In 13 cases, continuous periodontal structures were seen and the defect thereby separated from the root. The findings support the conclusion that cases clearly showing features of incomplete healing (scar tissue) at the regular follow-up 1 yr after surgery can be regarded as successes. They need not be recorded for further systematic control. A general follow-up program for apicectomy cases is suggested.

A strategy for the diagnosis of periapical pathosis

This study investigated intra- and interexaminer variation in diagnosing periapical pathosis and further tested a procedure with discussion and joint evaluation. When the study material was allocated to one of the groups designated successful, uncertain, or failure, there was 82% agreement between both observers. Cohens k was 0.61. The total agreement after joint evaluation of the disagreement cases was raised to 98%. The group uncertain was then reevaluated jointly and the cases placed, if possible, into the groups success or failure. By this procedure 98% of all cases fitted into the success/failure system. During the discussion of the disagreement cases, the radiologist could sometimes demonstrate special anatomical or technical characteristics which served to convince the endodontist that his first diagnosis had been incorrect; the reverse also occurred. Results indicate that by applying this strategy (a) variation between observers was reduced to an acceptable level; (b) obvious false recordings were few; and (c) diagnoses could be made which were directly related to the choice of treatment.

Root length, crown height, and root morphology in Turner syndrome

Root length, crown height, and root morphology were studied on intraoral and panoramic radiographs in 33 Turner syndrome patients aged 7.0-16.7 years, subdivided on the basis of karyotype. Thirty-three normal girls aged 10.2-16.4 years served as controls. In the 45X patients and, with the exception of a few teeth, also in the isochromosome and mosaic karyotypes, root length and crown height of incisors, canines, and premolars were significantly reduced. Some teeth showed altered crown-root proportions. Maxillary first premolars showed a significantly increased number of two-rooted and three-rooted variants. Mandibular premolars and molars had a complex root morphology, and a classification system was established including four premolar and six molar root types. Premolars had a significantly increased number of root components. Some of the variants, such as a molar-like second premolar, are apparently specific for these patients. On several first molars a radix entomolaris was identified. Two separate mesial and one or two separate distal roots were also frequently seen. Our investigation demonstrates that X-chromosome deficiency influences root formation.

Overextended gutta-percha and Kloroperka N-ö root canal fillings: Radiographic findings after 10-17 years

A representative sample, 55%, of the patients treated endodontically by undergraduate students in a teaching clinic during the years 1963 to 1969 were reexamined 10-17 years later. Gutta-percha/Kloroperka-NO root fillings (282), classified as having surplus material at the time of treatment, were evaluated in follow-up radiographs. In about 80% of the cases of overfilling, no excess root filling material could be traced at the reexamination. In a few cases only, the appearance of the excess material was nearly identical to that at the time of treatment, whereas the remaining overfillings (18%) showed a reduced size. Among the recorded variables only one seemed to have a major impact on the prognosis--namely, the presence or absence of an apical radiolucency at the time of treatment, indicating that infection was the important factor when failures occurred. Apical overfilling per se had little influence on the long-term healing result as judged radiographically.

Skeletal maturity, dental maturity, and eruption in young patients with Turner syndrome

A major problem for patients with Turner syndrome is their small body height. The rapid biotechnologic development has now made treatment with growth hormone possible at a larger scale. The aim of this investigation was to evaluate skeletal maturity, dental maturity, and eruption in a group of young patients before hormone therapy. The material comprised 33 patients aged 7-16.7 years. The skeletal maturity, as judged from hand radiographs, was on an average 2.3 years retarded (p < 0.001) and showed increasing retardation with increasing age. The dental maturity, assessed from the formation stages of the permanent teeth on panoramic radiographs, was accelerated, with a mean value of 1 year (p < 0.001). The timing of clinical eruption did not differ significantly from that of our reference material; the Turner girls were on an average 3.7 months ahead. Several patients had local eruption problems, especially in the maxillary lateral segments. It is suggested that disharmony between tooth size and arch size may contribute to this problem.

Tooth crown size and morphology in Turner syndrome

The aims of this investigation were to analyze permanent tooth crown size and morphology and to perform symmetry analysis between corresponding teeth on the right and the left side. The material comprised 32 Turner syndrome patients aged 7-16.7 years. As controls served 33 normal girls 10.2-16.7 years old. The mesiodistal diameter was significantly reduced for every tooth measured except for the maxillary canine. The buccolingual dimension was reduced only for some teeth. Eleven morphologic traits were defined. Ten of these were identified in the Turner patients; seven occurred in the controls as well, but at a lower frequency. Some of the traits have not been described earlier for this group of patients. There was a significant difference between Turner and control patients both in the number of patients with bilateral tooth asymmetries and in the number of corresponding tooth pairs in the maxilla with bilateral asymmetry. No significant differences were found between the 45X patients and the other karyotypes. Maxillary central incisors showed a surprisingly high relative frequency (38.5%) of bilateral asymmetry.

Mineral content and crystal size in mature rat incisor enamel. A correlated electron microprobe and electron microscope study.

The calcium and phosphorus contents of enamel from the erupted portion of the rat incisor were determined by electron microprobe analysis. Thirty micrometers from the enamel surface the calcium content averaged 35.5% and the phosphorus content 16.9%, indicating a mineral content of approximately 88% (range 84–95%) by volume. Electron microscopy of the same specimen material revealed that the hydroxyapatite crystals generally had an irregular cross-sectional profile. Neighboring crystals were often separated by a narrow slit, 10–25 in width, but frequently no intervening space could be seen. Calculations of the mineral content based on the electron micrographs were in good agreement with the results of the elemental analysis. The regular, hexagonal forms previously described in developing rat incisor enamel are not characteristic of the mature enamel. In this tissue, the mineral crystals are as irregular in shape as those in human enamel.

Detection of mineral loss in approximal enamel by subtraction radiography

The purpose of the present study was to determine whether digital subtraction radiography will improve detectability of small, mechanically prepared defects within dental enamel. Lesions with an extent of 1 mm in vertical direction and representing 5% to 10% mineral loss in the direction of the x-ray beam were prepared in eight extracted molars. Radiographs of teeth with defects were subtracted from radiographs taken before the lesions were prepared. Seven observers evaluated the images using a five-point confidence rating scale (receiver operating characteristic technique). Examination of the original radiographs showed increasing accuracy of radiographic interpretation with increasing mineral loss as judged from the areas beneath the receiver operating characteristic curves. The same observation was made using subtraction images with and without contrast enhancement. There was no indication that subtracted images provided better diagnostic validity than the original radiographs. In conclusion, subtraction images do not seem to improve the diagnosis of well-defined lesions within dental enamel.

Electron probe microanalysis of secondary carious lesions associated with silver amalgam fillings

Secondary caries associated with silver amalgam fillings is characterized by outer lesions and cavity wall lesions. In this study the content of minerals and the penetration of elements from the amalgam into such lesions were analyzed. In sections of 11 teeth including cases of natural secondary caries and experimental in vitro and in vivo lesions around silver amalgam fillings the distribution of Ca, P, Mg, Zn, Sn, Cu, Ag and Hg was studied by means of two-dimensional X-ray images, linear scans and point analyses. Dentine wall lesions where microradiographs had shown increased radiopacity relative to intact tissue, exhibited considerably reduced Ca and P values. The outer portion of the radiopaque areas contained 5--8% Zn and Sn, decreasing to less than 0.1% at a varying distance up to 130 mum from the cavity wall. Hg was not detected, nor was Ag, except in one specimen. The increased radiopacity of this zone as observed on microradiographs is, therefore, obviously caused by the presence of Zn and Sn. Zn and Sn had also penetrated into the moderately demineralized enamel lesions, but the concentrations were generally lower than those observed in the dentine.

Number of teeth and tooth loss of former dental school patients Follow-up study after 10-17 years

Persons (n = 431) who had received endodontic and other treatment at the School of Dentistry in Bergen in the 1960s were invited to attend an examination in 1980, some 10-17 years after their first course of treatment. The age range initially had been 16-55 years. The attendance rate was 55% (149 women and 89 men) and was higher for the older age groups. Data from pre- and post-treatment records were added to the information obtained in 1980. Those who attended in 1980 had had 22.8 teeth at the initial examination and 21.2 teeth after their first course of treatment in the 1960s. In 1980 they had 19.3 teeth. About 20% of the persons had the same number of teeth at all three examinations, and 43% had not lost teeth after completing treatment at the school. Molars and maxillary teeth were most likely to have been extracted. This was also the case for teeth lost during the first course of treatment. Some 4% of the individuals had become edentulous. Conventional dental treatment had not prevented further tooth loss; the number of remaining teeth within each age group was about the same in 1980 as in the 1960s.