Risk factors of chronic periodontitis on healing response: a multilevel modelling analysis

Abstract

BackgroundChronic periodontitis is a multifactorial polygenetic disease with an increasing number of associated factors that have been identified over recent decades. Longitudinal epidemiologic studies have demonstrated that the risk factors were related to the progression of the disease. A traditional multivariate regression model was used to find risk factors associated with chronic periodontitis. However, the approach requirement of standard statistical procedures demands individual independence. Multilevel modelling (MLM) data analysis has widely been used in recent years, regarding thorough hierarchical structuring of the data, decomposing the error terms into different levels, and providing a new analytic method and framework for solving this problem. The purpose of our study is to investigate the relationship of clinical periodontal index and the risk factors in chronic periodontitis through MLM analysis and to identify high-risk individuals in the clinical setting.MethodsFifty-four patients with moderate to severe periodontitis were included. They were treated by means of non-surgical periodontal therapy, and then made follow-up visits regularly at 3, 6, and 12 months after therapy. Each patient answered a questionnaire survey and underwent measurement of clinical periodontal parameters.ResultsCompared with baseline, probing depth (PD) and clinical attachment loss (CAL) improved significantly after non-surgical periodontal therapy with regular follow-up visits at 3, 6, and 12 months after therapy. The null model and variance component models with no independent variables included were initially obtained to investigate the variance of the PD and CAL reductions across all three levels, and they showed a statistically significant difference (P < 0.001), thus establishing that MLM data analysis was necessary. Site-level had effects on PD and CAL reduction; those variables could explain 77–78% of PD reduction and 70–80% of CAL reduction at 3, 6, and 12 months. Other levels only explain 20–30% of PD and CAL reductions. Site-level had the greatest effect on PD and CAL reduction.ConclusionsNon-surgical periodontal therapy with regular follow-up visits had a remarkable curative effect. All three levels had a substantial influence on the reduction of PD and CAL. Site-level had the largest effect on PD and CAL reductions.Electronic supplementary materialThe online version of this article (10.1186/s12911-017-0533-2) contains supplementary material, which is available to authorized users.

Fine-Tuning Multilevel Modeling of Risk Factors Associated with Nonsurgical Periodontal Treatment Outcome

“…The results of this retrospective study show that disdaining any level may lead to inaccurate conclusions, and is in agreement with previous research 19,20,29 . The variance component models were used to weigh and compare risk factors of moderate to severe forms of periodontitis after NSPT.…”

“…Unlike previous studies, these patients presented decreased tendency for Among tooth-level, anterior teeth (incisors and canines) had a more significant reduction of PD and CAL than molars throughout the follow-up time, but between molar and premolars, this significance was only expressed at 6 and 12 months. These results are in accordance with previous studies 21,23,28,29,40 , although Jiao et al 28 compared molar and non-molar teeth while Song et al 29 did not show as much meaning in the reduction of PD. As is widely accepted, molars have the worse healing prognosis due to anatomic and morphologic characteristics such as furcations and size of entrance, root trunk length, bifurcation ridges, root concavities and cervical enamel projections 12,40,41 .…”

“…Since its proposal in periodontology research 16 , multilevel analysis began to be employed to study periodontitis' onset risk factors 17,19,20,25,27 , the effect of risk factors in nonsurgical and surgical periodontal therapies 21,23,24,28,29 and in the prediction of bone and tooth loss in maintained periodontal patients 18,22,26 . Though in periodontitis' onset risk studies we reckon that all sites are potentially susceptible, in studies on periodontal therapies we should focus only in treated sites, and in this sense, the combination of initial sound and unsound locations may mislead and skew the results.…”

“…Multilevel modeling (MLM) was proposed to periodontal research by Albandar & Goldstein 16 in an attempt to integrate explanatory variables in a hierarchical clustered data analysis. Since then, various articles validated the usefulness of that analysis, providing clear insights in periodontal research, from disease onset and progression to risk factors on healing response [17][18][19][20][21][22][23][24][25][26][27][28][29] .…”

“…Apart from the extensive literature of NSPT outcomes [11][12][13] , MLM approaches to NSPT upshots are not so common but they have demonstrated that smoking habits, tooth type, antibiotherapy, baseline probing depth (PD), baseline clinical attachment loss (CAL), baseline teeth mobility, and frequency of periodontal maintenance are relevant factors for the NSPT success 21,23,24,28,29 . It is noteworthy that this is the first time a MLM analysis is applied to a Portuguese periodontitis patient's sample to highlight what factors have influenced the NSPT therapeutic result.…”