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In psychological networks, one limitation of the most used community detection algorithms is that they can only assign each node (symptom) to a unique community, without being able to identify overlapping symptoms. The clique percolation (CP) is an algorithm that identifies overlapping symptoms but its performance has not been evaluated in psychological networks. In this study, we compare the CP with model parameters chosen based on fuzzy modularity (CPMod) with two other alternatives, the ratio of the two largest communities (CPRat), and entropy (CPEnt). We evaluate their performance to: (1) identify the correct number of latent factors (i.e., communities); and (2) identify the observed variables with substantive (and equally sized) cross-loadings (i.e., overlapping symptoms). We carried out simulations under 972 conditions (3x2x2x3x3x3x3): (1) data categories (continuous, polytomous and dichotomous); (2) number of factors (two and four); (3) number of observed variables per factor (four and eight); (4) factor correlations (0.0, 0.5, and 0.7); (5) size of primary factor loadings (0.40, 0.55, and 0.70); (6) proportion of observed variables with substantive cross-loadings (0.0%, 12.5%, and 25.0%); and (7) sample size (300, 500, and 1000). Performance was evaluated through the Omega index, Mean Bias Error (MBE), Mean Absolute Error (MAE), sensitivity, specificity, and mean number of isolated nodes. We also evaluated two other methods, Exploratory Factor Analysis and the Walktrap algorithm modified to consider overlap (EFA-Ov and Walk-Ov, respectively). The Walk-Ov displayed the best performance across most conditions and is the recommended option to identify communities with overlapping symptoms in psychological networks., (© 2024. The Author(s).)

Experimental studies in animals and in vitro have shown the usefulness of photodynamic therapy (PDT) as an adjunct to periodontal treatment. The aim of this study was to evaluate the long-term clinical and microbiological effects of PDT associated with nonsurgical periodontal treatment. Three sites in each of 33 patients with chronic periodontitis were randomly allocated in a split-mouth design to a treatment group: (1) scaling and root planing (SRP group); (2) SRP and irrigation with toluidine blue O (TBO group); and (3) SRP, irrigation with TBO and low-level laser irradiation (PDT group). Clinical parameters including visible plaque index, bleeding gingival index, bleeding on probing, probing depth, gingival recession and clinical attachment level were measured at baseline, and after 60, 90 and 180 days. Additionally, subgingival plaque samples were collected for microbiological analysis by PCR. Intergroup and intragroup statistical analyses were performed. All treatment groups showed an improvement in all clinical parameters, and a significant reduction in the proportion of sites positive for periodontopathogens at 60, 90 and 180 days compared to baseline (p < 0.05). None of the periodontal parameters showed a significant difference among the groups (p > 0.05). At 180 days, PDT treatment led to a significant reduction in the percentage of sites positive for all bacteria compared to SRP alone (p < 0.05). Within the limits of this study it may be concluded that PDT as an adjunct to periodontal treatment produced statistically significant reductions in some of the key periodontal pathogens but produced no statistically significant benefit in terms of clinical outcome.