Manpower planning in periodontology – how many specialists do we need?

Given that one of the major focus points within this issue of the journal is 'practical periodontal medicine' and the relationship between periodontal disease and systemic chronic diseases, it is surprising that we have no indication of the manpower required to secure better oral and general health in this field. Despite many of the heralded improvements in dental health reported in the Adult Dental Health Survey 2009, as monitored by the falling rates of edentulous subjects and decayed, missing and filled teeth (DMF), the overall increase between 1998 and 2009 in the number of subjects with deep pockets from 6% to 8% has largely gone unnoticed! This is a major concern given that most other indicators of oral health have improved over this time period. Furthermore, the tissue damage associated with periodontitis is largely irreversible, and has consequences not only for oral function and quality of life, but also may adversely impact on aspects of general health. This article aims to highlight why we need specialists in periodontics, which patients should be referred to them, how big a problem periodontal disease is and how many specialists in periodontics would be required to meet this treatment need. Estimates are made using the information gained from the Adult Dental Health Survey 2009 and the Office for National Statistics 2011 census, along with estimates of the average patient pool managed within specialist periodontal practices. However, the paper emphasises that these are estimates based on incomplete information which would be necessary to allow more complete models of manpower planning to be used.</p

Significance of Periodontal Risk Assessment in the recurrence of periodontitis and tooth loss

Aim: To investigate the association of the Periodontal Risk Assessment (PRA) model categories with periodontitis recurrence and tooth loss during supportive periodontal therapy (SPT) and to explore the role of patient compliance. Material and Methods: In a retrospective cohort, PRA was performed for 160 patients after active periodontal therapy (APT) and after 9.5 ± 4.5 years of SPT. The recurrence of periodontitis and tooth loss were analysed according to the patient's risk profile (low, moderate or high) after APT and compliance with SPT. The association of risk factors with tooth loss and recurrence of periodontitis was investigated using logistic regression analysis. Results: In 18.2% of patients with a low-risk profile, in 42.2% of patients with a moderate-risk profile and in 49.2% of patients with a high-risk profile after APT, periodontitis recurred. During SPT, 1.61 ± 2.8 teeth/patient were lost. High-risk profile patients lost significantly more teeth (2.59 ± 3.9) than patients with moderate- (1.02 ± 1.8) or low-risk profiles (1.18 ± 1.9) (Kruskal–Wallis test, p=0.0229). Patients with erratic compliance lost significantly (Kruskal–Wallis test, p=0.0067) more teeth (3.11 ± 4.5) than patients compliant with SPT (1.07 ± 1.6). Conclusions: In multivariate logistic regression analysis, a high-risk patient profile according to the PRA model at the end of APT was associated with recurrence of periodontitis. Another significant factor for recurrence of periodontitis was an SPT duration of more than 10 years

An abbreviated caries clinical trial design validated over 24 months

Conventional caries trials last from 24 to 36 months. This study evaluated whether the previously established difference in efficacy between 1000- and 2500-ppm-fluoride dentifrices could be detected after 12 months. Caries was assessed by clinical visual assessment (CVA-simplified version of Dundee Selectable Threshold Method - DSTM), bitewing radiography, and Fiber Optic Transillumination (FOTI). Changes in status for individual surfaces were classified by means of pre-prepared matrices as 0 (unchanged), +1 (initiation or progression), or -1 (regression) and summed for each subject to yield an event score. Mean group event scores were calculated for each product. DSTM at the D1 [enamel and dentin] threshold showed significant inter-group differences in mean event scores (p &lt; 0.003) and D1MFS increment (&lt; 0.007) at 12 months; these were confirmed at 24 months by traditional increment analysis (CVA &amp; FOTI at the D3 (dentin only) threshold + radiography, p &lt; 0.03). This study confirms the validity of an abbreviated trial protocol

Cell cycle regulation of central spindle assembly

The bipolar mitotic spindle is responsible for segregating sister chromatids at anaphase. Microtubule motor proteins generate spindle bipolarity and enable the spindle to perform mechanical work. A major change in spindle architecture occurs at anaphase onset when central spindle assembly begins. This structure regulates the initiation of cytokinesis and is essential for its completion. Central spindle assembly requires the centralspindlin complex composed of the Caenorhabditis elegans ZEN-4 (mammalian orthologue MKLP1) kinesin-like protein and the Rho family GAP CYK-4 (MgcRacGAP). Here we describe a regulatory mechanism that controls the timing of central spindle assembly. The mitotic kinase Cdk1/cyclin B phosphorylates the motor domain of ZEN-4 on a conserved site within a basic amino-terminal extension characteristic of the MKLP1 subfamily. Phosphorylation by Cdk1 diminishes the motor activity of ZEN-4 by reducing its affinity for microtubules. Preventing Cdk1 phosphorylation of ZEN-4/MKLP1 causes enhanced metaphase spindle localization and defects in chromosome segregation. Thus, phosphoregulation of the motor domain of MKLP1 kinesin ensures that central spindle assembly occurs at the appropriate time in the cell cycle and maintains genomic stability

Picomolar fluorescent probes for compound affinity determination to carbonic anhydrase IX expressed in live cancer cells

Numerous human cancers, especially hypoxic solid tumors, express carbonic anhydrase IX (CAIX), a transmembrane protein with its catalytic domain located in the extracellular space. CAIX acidifies the tumor microenvironment, promotes metastases and invasiveness, and is therefore considered a promising anticancer target. We have designed a series of high affinity and high selectivity fluorescein-labeled compounds targeting CAIX to visualize and quantify CAIX expression in cancer cells. The competitive binding model enabled the determination of common CA inhibitors’ dissociation constants for CAIX expressed in exponentially growing cancer cells. All tested sulfonamide compounds bound the proliferating cells with similar affinity as to recombinantly purified CAIX. The probes are applicable for the design of selective drug-like compounds for CAIX and the competition strategy could be applied to other drug targets

Picomolar fluorescent probes for compound affinity determination to carbonic anhydrase IX expressed in live cancer cells

Numerous human cancers, especially hypoxic solid tumors, express carbonic anhydrase IX (CAIX), a transmembrane protein with its catalytic domain located in the extracellular space. CAIX acidifies the tumor microenvironment, promotes metastases and invasiveness, and is therefore considered a promising anticancer target. We have designed a series of high affinity and high selectivity fluorescein-labeled compounds targeting CAIX to visualize and quantify CAIX expression in cancer cells. The competitive binding model enabled the determination of common CA inhibitors' dissociation constants for CAIX expressed in exponentially growing cancer cells. All tested sulfonamide compounds bound the proliferating cells with similar affinity as to recombinantly purified CAIX. The probes are applicable for the design of selective drug-like compounds for CAIX and the competition strategy could be applied to other drug targets