Patterns of periodontal disease progression based on linear mixed models of clinical attachment loss

AimThe goal of the present longitudinal cohort study was to examine patterns of periodontal disease progression at progressing sites and subjects defined based on linear mixed models (LMM) of clinical attachment loss (CAL).Materials and MethodsA total of 113 periodontally healthy and 302 periodontitis subjects had their CAL calculated bimonthly for 12 months. LMMs were fitted for each site and the predicted CAL levels used to categorize their progression state. Participants were grouped based on the number of progressing sites into unchanged, transitional and active subjects. Patterns of periodontal disease progression were explored using descriptive statistics.ResultsProgression occurred primarily at molars (50% of progressing sites) and inter‐proximal sites (72%), affected a higher proportion of deep than shallow sites (2.7% versus 0.7%), and pocketing was the main mode of progression (49%). We found a low level of agreement (47%) between the LMM and traditional approaches to determine progression such as change in CAL ≥3 mm. Fourteen per cent of subjects were classified as active and among those 93% had periodontitis. The annual mean rate of progression for the active subjects was 0.35 mm/year.ConclusionProgressing sites and subjects defined based on LMMs presented patterns of disease progression similar to those previously reported in the literature.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142020/1/jcpe12827.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142020/2/jcpe12827_am.pd

Efficacy of Chlorhexidine Varnish for the Prevention of Adult Caries: A Randomized Trial

The Prevention of Adult Caries Study, an NIDCR-funded multicenter, double-blind, randomized clinical trial, enrolled 983 adults (aged 18-80 yrs) at high risk for developing caries (20 or more intact teeth and 2 or more lesions at screening) to test the efficacy of a chlorhexidine diacetate 10% weight per volume (w/v) dental coating (CHX). We excluded participants for whom the study treatment was contraindicated or whose health might affect outcomes or ability to complete the study. Participants were randomly assigned to receive either the CHX coating (n = 490) or a placebo control (n = 493). Coatings were applied weekly for 4 weeks and a fifth time 6 months later. The primary outcome (total net D1-2FS increment) was the sum of weighted counts of changes in tooth surface status over 13 months. We observed no significant difference between the two treatment arms in either the intention-to-treat or per-protocol analyses. Analysis of 3 protocol-specified secondary outcomes produced similar findings. This trial failed to find that 10% (w/v) chlorhexidine diacetate coating was superior to placebo coating for the prevention of new caries (Clinicaltrials.gov registration number NCT00357877)

Comparison between polymerase chain reaction-based and checkerboard DNA hybridization techniques for microbial assessment of subgingival plaque samples Periodontal diseases are infections caused primarily by bacteria living in

Abstract Aim: To compare polymerase chain reaction (PCR) with subsequent reverse hybridization (micro-IDent test) and checkerboard DNA-DNA hybridization for the identification of 13 bacterial species in subgingival plaque samples. Material and Methods: Subgingival plaque samples were taken using paper points and curettes from two sites each with pocket depth o4, 4-6 and 46 mm at baseline and 3 months in 25 periodontitis subjects and two sites in 25 periodontally healthy subjects. Samples were analysed for their content of 13 bacterial species using both assays. Similarities for each species between techniques were determined using regression analysis. Differences between health and periodontitis were determined using the Mann-Whitney test. Results: Three hundred and fifty samples were evaluated using both techniques. Regression analysis indicated that 10/13 test species showed significant positive correlations between the counts determined by checkerboard analysis and levels determined by the PCR-based test after adjusting for 13 comparisons. The highest rank correlations of 0.58, 0.49 and 0.46 were seen for Treponema denticola, Fusobacterium nucleatum and Eubacterium nodatum, respectively (po0.0001). Both tests could distinguish samples from healthy and periodontitis subjects. Conclusion: Detection patterns of 10/13 test species in subgingival plaque samples from periodontitis and healthy subjects were similar using the two molecular techniques

The effect of repeated

removal on the composition of the supra-and subgingival microbiota Abstract Background, aims: The purpose of the present investigation was to determine the effect of weekly professionally administered supragingival plaque removal on the composition of the supra and subgingival microbiota. Methods: 18 adult subjects with periodontitis who had been treated and were in a maintenance phase of therapy were clinically and microbiologically monitored at baseline, 3, 6 and 12 months. After the baseline visit, the subjects received scaling and root planing followed by professional supragingival plaque removal every week for 3 months. Clinical measures of plaque accumulation, bleeding on probing (BOP), gingival redness, suppuration, pocket depth and attachment level were made at 6 sites per tooth at each visit. Separate supra (NΩ1804) and subgingival (NΩ1804) plaque samples were taken from the mesial aspect of all teeth excluding third molars in each subject at each time point and evaluated for their content of 40 bacterial taxa using checkerboard DNA-DNA hybridization. Significance of changes in mean counts, prevalence and proportions of bacterial species over time in both supra and subgingival samples were determined using the Quade test and adjusted for multiple comparisons. Results: Mean % of sites exhibiting plaque, gingival redness and BOP were significantly reduced during the course of the study. Significant decreases in mean counts were observed in both supra and subgingival samples. Mean total DNA probe counts (¿10 5 , ∫SEM) at baseline, 3, 6 and 12 months were: 133∫19, 95∫25, 66∫6, 41∫6 (pϽ0.001) for supragingival samples and 105∫22, 40∫10, 19∫4, 13∫3 (pϽ0.001) for subgingival samples. Mean counts of 22 of 40 and 34 of 40 species tested were significantly reduced in the supra and subgingival samples respectively over the monitoring period. For example, mean counts of Porphyromonas gingivalis ¿10 5 at baseline, 3, 6 and 12 months in the subgingival plaque samples were 2.0∫0.4, 0.5∫0.2, 0.6∫0.3, 0.3∫0.1 (pϽ0.001); Bacteroides forsythus 2.0∫0.6, 0.4∫0.1, 0.4∫0.2, 0.1∫0.2 (pϽ0.001); Treponema denticola 3.4∫1.1, 0.8∫0.3, 0.4∫0.2, 0.3∫0.3 (pϽ0.01). Similar reductions were seen in supragingival plaque samples. While counts were markedly reduced by professional plaque removal, the proportion and prevalence of the 40 test species were marginally affected

Modelling changes in clinical attachment loss to classify periodontal disease progression

AimThe goal of this study was to identify progressing periodontal sites by applying linear mixed models (LMM) to longitudinal measurements of clinical attachment loss (CAL).MethodsNinety‐three periodontally healthy and 236 periodontitis subjects had their CAL measured bi‐monthly for 12 months. The proportions of sites demonstrating increases in CAL from baseline above specified thresholds were calculated for each visit. The proportions of sites reversing from the progressing state were also computed. LMM were fitted for each tooth site and the predicted CAL levels used to categorize sites regarding progression or regression. The threshold for progression was established based on the model‐estimated error in predictions.ResultsOver 12 months, 21.2%, 2.8% and 0.3% of sites progressed, according to thresholds of 1, 2 and 3 mm of CAL increase. However, on average, 42.0%, 64.4% and 77.7% of progressing sites for the different thresholds reversed in subsequent visits. Conversely, 97.1%, 76.9% and 23.1% of sites classified as progressing using LMM had observed CAL increases above 1, 2 and 3 mm after 12 months, whereas mean rates of reversal were 10.6%, 30.2% and 53.0% respectively.ConclusionLMM accounted for several sources of error in longitudinal CAL measurement, providing an improved method for classifying progressing sites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134161/1/jcpe12539_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134161/2/jcpe12539.pd