PubMed Health⌕ Search

Biomedical subjects

H C Lawless

Publications and source records attributed to H C Lawless.

2 recordsLinked to original sources

Important differences in clinical data from third, second, and first generation periodontal probes.

This study compared relative attachment levels (RAL) and probable crevice depths (PCD) from 6 periodontal probes (1 third, 4 second, and 1 first generation). A single clinician recorded RAL and PCD in 6 patients with chronic adult periodontitis (mean age 48.2 years) during two visits (interval: 1 week) using a Latin square examination order. Replicate measurements were recorded at the 4 interproximal sites of the Ramford index teeth to examine intra-probe differences. Additional single measurements were recorded at similar sites of units 11, 26, 31 and 46 to investigate interprobe differences. Intra-probe RAL and PCD reproducibility was < or = 1 mm at > 94% of the sites. All intra-probe Pearson correlation coefficients were > 0.85 (P = 0.00). Inter-probe RAL and PCD agreement was < or = 1 mm at > 49% of the sites for RAL and > 61% of the sites for PCD. All inter-probe Pearson correlation coefficients were > 0.42 (P = 0.00) for RAL and > 0.49 (P = 0.00) for PCD. Analyses of variance showed significant differences in RAL and PCD between the first generation probe and the second generation probes (P < 0.005); in RAL between the third generation probe and the first and second generation probes (P = 0.0354); and in PCD between the third generation probe and the first and second generation probes (P = 0.0475). Inter-probe differences were clinically significant in the recorded percentages of pockets > or = 4 mm and > or = 6 mm. Significant inter-probe differences were found in RAL and PCD which have clinical importance in data interpretation and comparison.

Adult↗

Option-4 algorithm for automated disc probe: reduction in the variance of site-specific relative attachment level measurements.

Physical periodontal measurement is plagued by many confounders which result in aberrant values. Replicate measurements can reduce the number of aberrant values, the measurement error, and the variance of site-specific measurements. This study aimed to reduce the variance of site-specific measurements by using a new clinical algorithm (the Option-4 algorithm) for an automated disk probe. A single clinician recorded full-mouth relative attachment levels (RAL) at one visit in 32 patients (mean age 45.5 years) with moderately advanced chronic adult periodontitis. RAL was recorded over two passes at six sites per tooth (4,675 sites). The algorithm accepted the first and second pass RALs (RAL1 and RAL2) if their difference was < or = 1 mm, otherwise a maximum of two further RALs (RAL3 and RAL4) were recorded until the difference between any two RALs was < or = 1 mm (SAL1 and SAL2): 4,048 sites (86.6%) required two recordings, 580 sites (12.4%) required three recordings and 47 sites (1%) required four recordings. Correlation coefficients for RAL1 and RAL2 and SAL1 and SAL2 (4,675 sites) were both > or = 0.91 (P = 0.00). Site-specific variances were calculated for RAL1 and RAL2 and SAL1 and SAL2. The mean of the RAL1/RAL2 site-specific variances (A) was 0.45 mm2 (range 0.00 mm2 to 35.28 mm2) whilst the mean of the SAL1/SAL2 variances (B) was 0.09 mm2 (range 0.00 mm2 to 0.5 mm2): the respective medians were 0.08 mm2 and 0.02 mm2. The study demonstrated high intra-examiner RAL reproducibility. The Option-4 algorithm produced an 80% reduction in the mean site-specific variance of RAL1/RAL2 (Y) and a 75% reduction in the median site-specific variance of RAL1/RAL2 (y = [(A - B)/A] x 100).

Adult↗