Periodontal Probing Depth Trajectory in 10 Years of Follow-Up as Associated With Tooth Loss

On a Bayesian multivariate survival tree approach based on three frailty models

This study compared the performance of the Bayesian multivariate survival tree approach constructed from extended Cox proportional hazard with gamma frailty term, and two shared gamma frailty models with exponential and Weibull baseline hazard function, respectively. A simulation study was applied to evaluate the impact of the baseline hazard function, number of clusters (200, 500, 1000), cluster size (5, 10, 20), and right censoring rate (10%, 50%, 80%) on the performance of classification. We generated 90 clustered survival datasets having correlated failure times and 50 covariates at cluster level and at individual level. Each dataset was resampling 1000 times by selecting clusters at random 70% as training datasets and the rest 30% as the test datasets. The performance of a Bayesian multivariate survival tree approach based on shared gamma frailty models with Weibull distribution provided the highest accuracy. All three models, the accuracy tended to increase with an increase in the cluster size and the number of clusters. The accuracy decreased monotonically with increasing the percentage of censoring rate. In conclusion, the use of the Bayesian multivariate survival tree approach constructed from the shared gamma frailty with baseline hazard function as Weibull distribution was recommended.

Treating Periodontitis Strictly Non-Surgically-A Retrospective Long-Term Analysis of Tooth Loss During Supportive Periodontal Care

Background/Objectives: Retrospective analysis of long-term periodontal tooth loss (PTL) during supportive periodontal care (SPC) in patients with Stage III/IV periodontitis who received strictly non-surgical periodontal treatment. Methods: Fully documented medical documentation of SPC > 5 years was analyzed at T0 (baseline), T1 (after Steps 1/2), and during SPC (T2). PTL, periodontal pocket depth (PD), bleeding on probing (BOP), tooth mobility (TM), furcation involvement (FI), and frequency of SPC were recorded. Each parameter was tested for significance in a bivariate analysis, before a multilevel logistic regression analysis was performed to identify possible factors with an impact on PTL during SPC. Results: A total of 51 women/64 men (T1 mean age 55.4 ± 10.3 yrs) were surveilled after 9.0 ± 2.4 yrs; 2647 teeth were included. On average, patients attended 10.6 ± 3.8 SPC sessions between T1 and T2; 77 patients (67%) attended at least 1/year. At T1, 68 teeth were lost; 6.1% of the remaining teeth showed FI, and 13.8% showed TM. During SPC, the PTL range was 118 (1.03 ± 1.21/patient). TM, FI, mean PD, and Stage IV periodontitis proved to be statistically significantly associated with increased PTL. Conclusions: PTL was low in this cohort. Nevertheless, at T1, it may be beneficial to focus on stopping TM by splinting the mobile teeth and reducing the PD or treating FI appropriately, understanding that these precise applications of surgical procedures could positively affect long-term tooth retention.