Análisis multinivel en periodontitis

background: treatment in patients with periodontitis occurs through mechanical therapy alone or combined with antibiotics and surgery. scientific evidence shows how some factors related to the subject and the site of the tooth may compromise treatment response. conventionally, the subject as a unit of analysis has been used, but it is not appropriate to treat observations of each periodontal site as if they were independent. objective: to compare the effect of factors associated with the sites of the teeth and the subject associated factors, on the outcome of periodontal therapy in studies using multilevel models in its analysis. development: a systematic review of the literature aimed at the treatment of periodontitis and analyzed with multilevel models was conducted. four randomized clinical trials, a quasi-experiment study and five longitudinal studies, was carried out in systemically healthy subjects. unlike conventional regression methods, the multilevel analysis found little influence of factors related tooth loss on individuals. the presence of plaque at site level, molars as well as furcation involvement and angular bone defects were associated with inadequate effects in therapy. conclusions: multilevel analysis revealed that the highest percentage of variance is attributed to the site level, while the lower is at patient level.