Furcation involvement, bone loss, tooth mobility, mean pocket depth and age strongly predicted tooth loss during SPT. Long-term retention of periodontally compromised molars was possible via conservative non-regenerative active and supportive therapy.

Graetz C, Dörfer CE, Kahl M, Kocher T, Fawzy El‐Sayed K, Wiebe J‐F, Gomer K, Rühling A. Retention of questionable and hopeless teeth in compliant patients treated for aggressive periodontitis. J Clin Periodontol 2011; 38: 707–714. doi: 10.1111/j.1600‐051X.2011.01743.x. Abstract Aim: The aim of this study was to determine the survival rates of questionable and hopeless teeth in patients with aggressive periodontitis (AgP) and chronic periodontitis (CP) during 15 years of supportive periodontal therapy (SPT). Materials and methods: Thirty‐four AgP and 34 CP patients (SPT10 years) with bone loss of 50% at 2 teeth were consecutively recruited. Bone loss was measured on digitized radiographs and teeth were categorized as “questionable” (50 to <70% bone loss) or as “hopeless” (70%). Progression in pocket probing depths (PPD) during SPT, tooth loss and reasons for extraction were analysed. Results: In AgP patients, 262 teeth were considered as questionable and 63 as hopeless (CP: 149/51). During active periodontal therapy, 25 questionable and 26 hopeless teeth were extracted (CP: 12/16). During 15.3 ± 4.1 years of SPT of AgP 28 questionable and 15 hopeless teeth were removed (CP: 28/12). The mean tooth loss per patient during SPT in total was 0.14 (AgP) and 0.16 (CP) teeth/year. There were no significant differences in tooth loss or longitudinal progression of PPD between AgP and CP patients. Conclusions: In patients with AgP, 88.2% (209 of 237) of questionable and 59.5% (22 of 37) of hopeless teeth survived 15 years during regular SPT in a dental school department.

Aim A range of predictors for tooth loss in periodontitis patients have been reported. We performed a systematic review and meta‐analysis to assess the consistency and magnitude of any association between a total of 12 predictors and tooth loss. Materials and Methods Medline/Embase/Central were searched for longitudinal studies investigating the association between predictors and tooth loss in periodontitis patients. Random‐effects meta‐analysis was performed, and study quality assessed. Results Twenty studies (15,422 patients, mean follow‐up: 12 years) were included. The mean annual tooth loss/patient was 0.12 (min./max: 0.01/0.36). Older patients (n = 8 studies; OR: 1.05, 95% CI: 1.03–1.08/year), non‐compliant ones (n = 11; 1.51, 1.06–2.16), diabetics (n = 7; 1.80, 1.26–2.57), those with IL‐1‐polymorphism (n = 3; 1.80; 1.29–2.52) and smokers (n = 15; 1.98, 1.58–2.48) had a significantly higher risk of tooth loss. Teeth with bone loss (n = 3; 1.04, 1.03–1.05/%), high probing pocket depth (n = 6; 3.19, 1.70–5.98), mobility (n = 4; 3.71, 1.65–8.38) and molars (n = 4; 4.22, 2.12–8.39), especially with furcation involvement (n = 5; 2.68, 1.75–4.08) also showed higher risks. Gender (n = 16; 0.95, 0.86–1.05) and endodontic affection (n = 3; 3.62, 0.99–13.2) were not significantly associated with tooth loss. Conclusions Older, non‐compliant, smoking or diabetic patients, and teeth with bone loss, high probing pocket depth, mobility, or molars, especially with furcation involvement showed higher risks of tooth loss.

Taken together, our results suggest considering periimplantitis and periodontitis as disease entities with shared as well as with distinct features, which should be reflected on the therapeutical as well as on the scientific level.

Previous candidate genes carry no susceptibility factors for AgP. Association of IL-10 rs61815643 with AgP is suggested. ANRIL is associated with periodontitis across different populations.

Based on available data and within its limitations, our study indicates that retaining FI molars via periodontal treatments might be more cost-effective than replacing them via ISCs. Changes in the underlying evidence or the setting might alter these results.

Recently, gingival margin-derived stem/progenitor cells isolated via STRO-1/magnetic activated cell sorting (MACS) showed remarkable periodontal regenerative potential in vivo. As a second-stage investigation, the present study's aim was to perform in vitro characterisation and comparison of the stem/progenitor cell characteristics of sorted STRO-1-positive (MACS+) and STRO-1-negative (MACS−) cell populations from the human free gingival margin. Cells were isolated from the free gingiva using a minimally invasive technique and were magnetically sorted using anti-STRO-1 antibodies. Subsequently, the MACS+ and MACS− cell fractions were characterized by flow cytometry for expression of CD14, CD34, CD45, CD73, CD90, CD105, CD146/MUC18 and STRO-1. Colony-forming unit (CFU) and multilineage differentiation potential were assayed for both cell fractions. Mineralisation marker expression was examined using real-time polymerase chain reaction (PCR). MACS+ and MACS− cell fractions showed plastic adherence. MACS+ cells, in contrast to MACS− cells, showed all of the predefined mesenchymal stem/progenitor cell characteristics and a significantly higher number of CFUs (P<0.01). More than 95% of MACS+ cells expressed CD105, CD90 and CD73; lacked the haematopoietic markers CD45, CD34 and CD14, and expressed STRO-1 and CD146/MUC18. MACS− cells showed a different surface marker expression profile, with almost no expression of CD14 or STRO-1, and more than 95% of these cells expressed CD73, CD90 and CD146/MUC18, as well as the haematopoietic markers CD34 and CD45 and CD105. MACS+ cells could be differentiated along osteoblastic, adipocytic and chondroblastic lineages. In contrast, MACS− cells demonstrated slight osteogenic potential. Unstimulated MACS+ cells showed significantly higher expression of collagen I (P<0.05) and collagen III (P<0.01), whereas MACS− cells demonstrated higher expression of osteonectin (P<0.05; Mann–Whitney). The present study is the first to compare gingival MACS+ and MACS− cell populations demonstrating that MACS+ cells, in contrast to MACS− cells, harbour stem/progenitor cell characteristics. This study also validates the effectiveness of the STRO-1/MACS+ technique for the isolation of gingival stem/progenitor cells. Human free gingival margin-derived STRO-1/MACS+ cells are a unique renewable source of multipotent stem/progenitor cells.

Periodontitis is one of the most common inflammatory diseases, with a prevalence of 11% worldwide for the severe forms and an estimated heritability of 50%. It is classified into the widespread moderate form chronic periodontitis (CP) and the rare early-onset and severe phenotype aggressive periodontitis (AgP). These different disease manifestations are thought to share risk alleles and predisposing environmental factors. To obtain novel insights into the shared genetic etiology and the underlying molecular mechanisms of both forms, we performed a two step-wise meta-analysis approach using genome-wide association studies of both phenotypes. Genotypes from imputed genome-wide association studies (GWAS) of AgP and CP comprising 5,095 cases and 9,908 controls of North-West European genetic background were included. Two loci were associated with periodontitis at a genome-wide significance level. They located within the pseudogene MTND1P5 on chromosome 8 (rs16870060-G, P = 3.69 × 10, OR = 1.36, 95% CI = [1.23-1.51]) and intronic of the long intergenic non-coding RNA LOC107984137 on chromosome 16, downstream of the gene SHISA9 (rs729876-T, P = 9.77 × 10, OR = 1.24, 95% CI = [1.15-1.34]). This study identified novel risk loci of periodontitis, adding to the genetic basis of AgP and CP.