Jostein Rise

An approach to epidemiologic assessment of complete dentures.

The condition of complete dentures was studied in an epidemiologic investigation of a representative sample of 241 persons aged 65–79 in the county of Troms in Northern Norway using an index comprising six professionally assessed indicators. These indicators were: Defects of the dentures, denture material, stability, retention, occlusion and denture-related mucosal lesions. Three scoring systems denoted system 1, 2 and 3 were applied to determine their influence on the distribution of unsatisfactory dentures. System 1 and 2 which contain weighted indicators, differ mainly in the weighting of retention and occlusion, while system 3 has only unweighted dichotomized indicators. The condition of the dentures was graded: Satisfactory—grade 0 and unsatisfactory—grades I, II, III, depending upon the number of unsatisfactory indicators. The result of the judgment did not reveal any significant difference between the systems, although system 3 differed somewhat. Unsatisfactory upper dentures were usually caused by...

The effect of verbal information and demonstration on denture hygiene in elderly people

The purpose of the present study was to investigate the effect of two oral hygiene information programs on denture hygiene. The programs were provided individually to healthy elderly denture wearers. Totally, 150 edentulous persons between 67 and 89 years of age were selected and randomly assigned to two experimental groups and one control group. In one test group (INFO) the participants were only given individual verbal information on how to remove denture plaque. The participants of the second test group (DEMO) received individual demonstration of denture cleaning in addition. One hundred and thirty-eight persons completed the study. The percentage plaque covering the maxillary denture base was assessed by a morphometric point-estimator scoring method at the start of the study and after 14 and 180 days. Verbal information resulted only in a short-term effect (14 days), whereas demonstration on how to remove denture plaque gave long-term (180 days) improvement of denture hygiene.

A study of examiner errors associated with measurement of denture plaque

The purpose of the present study was to compare the reproducibility and reliability of different methods of measuring the distribution of plaque on the fitting surface of maxillary dentures. Data from a clinical trial were used to determine the reproducibility of (1) the original Budtz-Jörgensen index, (2) a proposed morphometric method for facilitating the measurements by this index, and (3) the index of Schubert and Schubert. The recordings from previous tests of reproducibility of an additive index were used to estimate reliability by means of a test-retest procedure and the internal consistency method. The morphometric point-estimator scoring method gave the highest intra- and inter-examiner reproducibility for the three-graded scale (Scotts pi, 0.90 and 0.81) and for the five-graded scale (0.86 and 0.80). Reproducibility was markedly reduced when the distribution of denture plaque was assessed by visual examination (Scotts pi, 0.81 and 0.72), especially when using the five-graded scale (0.73 and 0.51). The PH index exhibited an intra-examiner reliability of 0.83 with the three-graded scale and 0.78 with the five-graded scale. The corresponding inter-examiner figures were 0.76 and 0.70. The test-retest method showed that in the areas M1 and M2 the mean amount of plaque was significantly reduced at the second examination, whereas no significant change occurred in areas T1 and T2. The reliability coefficients obtained by the additive index were greater than 0.88. Error variance was 8% and 12% of the total variance for this index but only 3% with the morphometric test method. The internal consistency reliability gave coefficients that were higher than those obtained by the test-retest method.

Radiographic quantification of alveolar bone level changes: Predictors of longitudinal bone loss

The purpose of the present study was to determine the relative importance of a set of predictors for the radiographic change in alveolar bone level over 2 years in a group of 180 subjects and to assess the fit of the applied multivariate model. The included predictors were age, sex, initial bone level, type of initial lesion, tooth type, proximal tooth surface, calculus, and the presence of metal crowns or proximal fillings. The multivariate method of choice was multiple classification analysis. The results indicated that in descending order tooth type, initial bone level, and age were the most important predictors. Sex, calculus, and crown and filling margins also showed significant direct effects (beta) on longitudinal bone loss (p less than 0.05). However, their relative importance was far less than that of tooth type, initial bone level, and age. Proximal side showed no significant direct effect. Using seven predictors, the applied multivariate model explained 20% of the variance in longitudinal bone loss.

Pattern of alveolar bone loss and reliability of measurements of the radiographic technique

The purposes of this paper were to study the pattern of bone loss among different teeth at the individual level and to study the effect of using different aggregated units of analysis on measurement error. Bone loss was assessed in standardized periapical radiographs from 293 subjects (18-68 years), and the mean bone loss score for each tooth type was calculated. These were then correlated by means of factor analysis to study the bone loss pattern. Reliability (measurement error) was studied by the internal consistency and the test-retest methods. The pattern of bone loss showed a unidimensional pattern, indicating that any tooth will work equally well as a dependent variable for epidemiologic descriptive purposes. However, a more thorough analysis also showed a multidimensional pattern in terms of four dimensions, which correspond to four tooth groups: incisors, upper premolars, lower premolars, and molars. The four dimensions accounted for 80% of the total variance. The multidimensional pattern may be important for the modeling of bone loss; thus different models may explain the four dimensions (indices) used as dependent variables. The reliability (internal consistency) of the four indices was satisfactory. By the test-retest method, reliability was higher when the more aggregated unit (the individual) was used.

Reliability of plaque and periodontal measurements estimated by the internal consistency method.

The purpose of this paper was to assess whether the internal consistency method could be used to estimate reliability of periodontal and plaque measurements. This method is based on the assumption of comparability of data from the left and right halves of the mouth. The material comprised data from 61 subjects (mean age, 43 years). Percentage of tooth surfaces with plaque index scores of at least 1, percentage of bleeding units (GI = 2), and the mean pocket depth were calculated for each half of the mouth. At the group level the mean variables, and there was a substantial degree of bilateral symmetry for all variables as measured by Pearsons r. Reliability coefficients were computed in accordance with the Spearman-Brown formula. Highest reliability coefficient was observed for pocket depth measurements (0.97), followed by plaque measurements (0.95), and , finally, gingival bleeding measurements (0.90). The internal consistency method seems promising in estimating reliability in epidemiologic surveys, but further studies should be initiated to substantiate this contention.