Clemens Walter

Strategic considerations in treatment planning: Deciding when to treat, extract, or replace a questionable tooth

Prosthodontists face the difficult task of judging the influence and significance of multiple risk factors of periodontal, endodontic, or prosthetic origin that can affect the prognosis of an abutment tooth. The purpose of this review is to summarize the critical factors involved in deciding whether a questionable tooth should be treated and maintained, or extracted and possibly replaced by dental implants. A MEDLINE (PubMed) search of the English, peer-reviewed literature published from 1966 to August 2009 was conducted using different keyword combinations including treatment planning, in addition to decision making, periodontics, endodontics, dental implants, or prosthodontics. Further, bibliographies of all relevant papers and previous review articles were hand searched. Tooth maintenance and the acceptance of risks are suitable when: the tooth is not extensively diseased; the tooth has a high strategic value, particularly in patients with implant contraindications; the tooth is located in an intact arch; and the preservation of gingival structures is paramount. When complete-mouth restorations are planned, the strategic use of dental implants and smaller units (short-span fixed dental prostheses), either tooth- or implant-supported, as well as natural tooth abutments with good prognoses for long-span FDPs, is recommended to minimize the risk of failure of the entire restoration.

Three‐dimensional imaging as a pre‐operative tool in decision making for furcation surgery

AIM To investigate the use of cone beam computed tomography (CBCT) in assessing furcation involvement (FI) and concomitant treatment decisions in maxillary molars. MATERIAL AND METHODS Twelve patients with generalized chronic periodontitis were consecutively recruited and CBCT was performed in maxillary molars (n=22) with clinical FI and increased probing pocket depths. CBCT images were analysed and FI, root length supported by bone and anatomical features were evaluated. FI and treatment recommendations based on clinical examinations and periapical radiographs were compared with data derived from CBCT images. RESULTS The estimated degree of FI based on clinical findings was confirmed in 27% of the sites, while 29% were overestimated and 44% revealed an underestimation according to CBCT analyses. Among degree I FI, 25% were underestimated, among degree II and II-III, the underestimation was as high as 75%, while all sites with degree III FI were confirmed in the CBCT. Discrepancies between clinically and CBCT-based therapeutic treatment approaches were found in 59-82% of the teeth, depending on whether the less invasive or the most invasive treatment recommendation was selected for comparison. CONCLUSIONS CBCT images of maxillary molars may provide detailed information of FI and a reliable basis for treatment decision.

Accuracy of three-dimensional imaging in assessing maxillary molar furcation involvement

AIM To assess the accuracy of cone beam computed tomography (CBCT) in detecting furcation involvement (FI) in maxillary molars. MATERIAL AND METHODS Fourteen patients with generalized advanced chronic periodontitis were consecutively recruited and treated non-surgically. In maxillary molars considered for furcation surgery due to increased FI and/or increased probing pocket depths during re-evaluation, CBCT was performed and the degree of FI was evaluated from the CBCT images. Furcation surgery was performed in 25 maxillary molars. Intra-surgical FI assessments were compared with data derived from CBCT images. RESULTS Overall, 84% of the CBCT data were confirmed by the intra-surgical findings (weighted kappa=0.926, 95% confidence interval: 0.681-1.0). While 14.7% (11 sites) were underestimated (CBCT less than intra-surgical value), in only 1.3% (one site) did the CBCT data lead to an overestimation compared with the intra-surgical analysis. The agreement between both assessments was the highest in distopalatal furcation entrances, followed by buccal and mesiopalatal. CONCLUSIONS CBCT images demonstrate a high accuracy in assessing the loss of periodontal tissue and classifying the degree of FI in maxillary molars.

Porphyromonas gingivalis Strain-Dependent Activation of Human Endothelial Cells

ABSTRACT Porphyromonas gingivalis is an important bacterium involved in periodontal diseases. Colonization by periodontopathogens has been associated with severe local inflammatory reactions in the connective tissue. In this study we characterized P. gingivalis-mediated infection and activation of human umbilical vein endothelial cells by using two strains of different virulence capacities, strains ATCC 53977 and DSMZ 20709. Both strains were able to adhere to and infect endothelial cells with an infection rate of 0.48% for ATCC 53977 and 0.007% for DSMZ 20709. The triggering of two signal transduction pathways in P. gingivalis-infected endothelial cells was demonstrated for both strains, with a rapid increase of p38 mitogen-activated protein kinase phosphorylation and a more delayed degradation of IκBα, followed by nuclear translocation of NF-κB. In addition, both strains induced enhanced expression of endothelial adhesion molecules E-selectin and intracellular adhesion molecule 1 (ICAM-1). Target cell activation was independent of bacterial fimbriae expression since the fimA knockout strain A7436 ΔfimA induced the same level of ICAM-1 as the corresponding wild type (A7436-WT). Thus, two P. gingivalis strains, ATCC 53799 and DSMZ 20709, infect endothelial cells and trigger signaling cascades leading to endothelial activation, which in turn may result in or promote severe local and systemic inflammation.

Are periodontal diseases really silent? A systematic review of their effect on quality of life

AIM Periodontal diseases (PDs) may play an important role in the effect oral health status has on a persons quality of life (QoL). The objective was to investigate the influence of PDs (gingivitis and periodontitis) on oral health-related QoL (OHRQoL) by systematically reviewing the literature. MATERIALS AND METHODS Studies using clinical periodontal examinations and validated survey instruments were included. Among 1134 citations initially identified through electronic and hand searching, 37 were eligible and data were extracted from full texts. A vote counting method was used for synthesis of the results. RESULTS Included studies were published between 2001 and 2014 and revealed considerable heterogeneity in participant selection, clinical assessments, and OHRQoL measures. A significant association between PDs and OHRQoL was reported in 28 studies, of which eight reported increasing impact with greater disease severity or extent. CONCLUSIONS Within the limits of the available literature, OHRQoL was affected by clinically assessed PDs. There was evidence for increased impairment with greater severity and extent of PDs, and the recognition of the association was increased when full mouth recording protocols were applied.

The epidemiological evidence behind the association between periodontitis and incident atherosclerotic cardiovascular disease

OBJECTIVES The objective of this study was to systematically review the epidemiological evidence for an association between periodontitis (PD) and incident atherosclerotic cardiovascular disease (ACVD), including coronary heart disease (CHD), cerebrovascular disease and peripheral arterial disease. METHODS Systematic review of cohort and case-control studies on the association of clinically or radiographically diagnosed PD and ACVD. RESULTS Overall, 12 studies were included in this study (six studies on CHD, three studies on cerebrovascular disease, two studies on both coronary heart and cerebrovascular disease mortality and one study on peripheral arterial disease).All but one study reported positive associations between various periodontal disease measures and the incidence of ACVD, at least in specific subgroups. The association was stronger in younger adults and there was no evidence for an association between PD and incident CHD in subjects older than 65 years. Only one study evaluated the association between PD and secondary cardiovascular events. CONCLUSIONS There is evidence for an increased risk of ACVD in patients with PD compared to patients without. However, this may not apply to all groups of the population. There is insufficient evidence for an association between PD and the incidence of secondary cardiovascular events.

Periodontal surgery in furcation-involved maxillary molars revisited--an introduction of guidelines for comprehensive treatment.

Maxillary molars with interradicular loss of periodontal tissue have an increased risk of additional attachment loss with an impaired long-term prognosis. Since accurate clinical analysis of furcation involvement is not feasible due to limited access, morphological variations and measurement errors, additional diagnostics, e.g., with cone-beam computed tomography, may be required. Surgical treatment options have graduated from a less invasive approach, i.e., keeping as much periodontal attachment as possible, to a more invasive approach: (1) open flap debridement with/without gingivectomy or apically repositioned flap and/or tunnelling; (2) root separation; (3) amputation/trisection of a root (with/without root separation or tunnel preparation); (4) amputation/trisection of two roots; and (5) extraction of the entire tooth. Tunnelling is indicated when the degree of root separation allows for opening of the interradicular region. Alternatively, root separation is performed particularly in root-canal treated teeth with reduced coronal tooth substance requiring crown restorations. As soon as the attachment of one or two roots in maxillary molars is severely reduced, root removal is indicated and performed either as amputation or trisection including the corresponding part of the clinical crown. While the indication for regenerative measures in maxillary molars with furcation involvement is very limited, extraction and replacement with implants is restricted, particularly in sites requiring complex alveolar ridge augmentation and sinus elevation. A systematic approach for decision making in furcation-involved maxillary molars is described in this overview, including what constitutes accurate diagnosis and what indications there are for the different surgical periodontal treatment options.

Active and passive smoking: assessment issues in periodontal research

Tobacco use, particularly active cigarette smoking, is a strong modifiable risk factor for periodontitis. Our primary aim is to provide a systematic review of the impact of environmental tobacco smoke on periodontal diseases. Nine publications were identified by electronic literature search up to September 2010. Epidemiological data for a US population sample and a cohort of Japanese men suggest that environmental tobacco smoke exposure may be associated with increase periodontitis prevalence and increased risk of periodontitis progression. Secondly, several methodological issues related to cigarette smoking in clinical and epidemiological research studies are discussed. Tobacco use history is a multi-dimensional phenomenon, with characteristics such as intensity, duration and time since cessation. Understanding these complexities of smoking history and accurate measurement of the exposure, using biomarkers and/or self-reported data as appropriate, are of central importance in clinical and epidemiological studies on the effects of active and passive smoking. The most appropriate approach to assess smoking exposure will vary according to the purpose and design of a particular study.

Microcalorimetric determination of the effects of amoxicillin, metronidazole, and their combination on in vitro biofilm.

BACKGROUND The mechanism of action of adjuvant antibiotic therapy in the treatment of peri-implantitis is not well understood. The aim of this study is to investigate antibiotic susceptibility of an in vitro biofilm by isothermal microcalorimetry (IMC). METHODS Titanium disks containing a 72-hour three-species biofilm (Streptococcus sanguinis DSM20068, Fusobacterium nucleatum ATCC10953, and Porphyromonas gingivalis DSM20709) were placed in a series of IMC ampoules with nutrient agar supplemented with increasing concentrations of amoxicillin, metronidazole, or their combination and incubated anaerobically for 10 days. Lag time and maximum growth rate were determined from continuous heat-flow recordings of metabolic activity. To validate the IMC biofilm results, adherent S. sanguinis and P. gingivalis were incubated anaerobically in medium supplemented with antibiotics at 37°C for 24 hours, and their vitality was determined by live/dead staining, conventional culturing, and IMC. RESULTS In all biofilm samples incubated with antibiotics, a prolonged lag phase was observed compared with controls (P <0.05). Maximum growth rate was significantly lower for samples treated with either amoxicillin or metronidazole compared with controls (P <0.05). Combining the antibiotics did not improve this effect. Concentrations exceeding 10 times the minimum inhibitory concentration completely inhibited the growth of adherent S. sanguinis and P. gingivalis, whereas lower concentrations resulted in only a delay in the lag phase. A poor correlation was observed between live/dead staining and conventional culturing. CONCLUSIONS IMC gives new evidence about antibiotic effects on oral biofilms and is more informative than conventional culture and live/dead assays. The combination of antibiotics was found to be more efficient than metronidazole alone; however, only minor differences in growth inhibition were detected compared with amoxicillin alone.

Smoking, Smoking Cessation, and Risk of Tooth Loss The EPIC-Potsdam Study

The aim of this study was to investigate the association between cigarette smoking and smoking cessation and the prevalence and incidence of tooth loss in a large cohort study in Germany. We analyzed data of 23,376 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC)–Potsdam study recruited between 1994 and 1998 from the general population in Potsdam and other parts of Brandenburg, Germany, who had complete data on cigarette smoking, tooth loss, and covariates. Negative binomial regression and tooth-specific logistic regression models were fit to evaluate the association between smoking and the baseline prevalence and incidence of tooth loss during follow-up, respectively. Cigarette smoking was associated with higher prevalence of tooth loss at baseline as well as higher incidence of tooth loss during follow-up. The association between smoking and the incidence of tooth loss was stronger in men than women and stronger in younger versus older individuals. Heavy smoking (≥15 cigarettes/d) was associated with >3 times higher risk of tooth loss in men (odds ratio, 3.6; 95% confidence interval, 3.0, 4.4) and more than twice the risk of tooth loss in women (odds ratio, 2.5; 95% confidence interval, 2.1, 2.9) younger than 50 y when compared with never smokers. Smoking cessation was consistently associated with a reduction in tooth loss risk, with the risk of tooth loss approaching that of never smokers after approximately 10 to 20 y of cessation.