M.M. Danser

Bio: M.M. Danser is an academic researcher from Academic Center for Dentistry Amsterdam. The author has contributed to research in topics: Toothbrush & Periodontitis. The author has an hindex of 16, co-authored 22 publications receiving 1068 citations.

Short‐term effect of full‐mouth extraction on periodontal pathogens colonizing the oral mucous membranes

Abstract: In this study, we investigate the prevalence of selected periodontal pathogens on the oral mucous membranes before and after full-mouth tooth extractions in patients with severe periodontitis. 8 patients were microbiologically examined 2 x before and 2 x after extraction; several locations on the oral mucous membranes, saliva, supra- and subgingival plaque, were sampled. Besides their presence in subgingival plaque, we detected before extraction on the mucous membranes Actinobacillus actinomycetemcomitans in 2 patients (mean 0.03%), Porphyromonas gingivalis in 6 patients (mean 9%), and Prevotella intermedia (mean 2%) and other Prevotella species (mean 7%) in all patients. At 1 and 3 months after extraction, A. actinomycetemcomitans and P. gingivalis could not be detected in any of these patients on the oral mucous membranes and in saliva, while from all patients still P. intermedia (mean 3%) and the other blackpigmented Prevotella species (mean 4%) could be isolated. These results indicate that the preferable habitat for A. actinomycetemcomitans and P. gingivalis is dental plaque in subgingival lesions. P. intermedia and the other blackpigmented Prevotella species can colonize the oral mucous membranes of edentulous patients irrespective of the presence of a subgingival microflora. We speculate that in periodontal patients the colonization of mucous membranes with P. gingivalis and A. actinomycetemcomitans is transient in nature and most likely the result of dissemination from the subgingival microflora. Thus it seems unlikely that edentulous patients constitute a reservoir of infection of P. gingivalis A. actinomycetemcomitans.

Tongue coating and salivary bacterial counts in healthy/gingivitis subjects and periodontitis patients

Abstract: Background The papillary structure of the dorsum of the tongue forms a unique ecological site that provides a large surface area favoring the accumulation of oral debris and microorganisms. These micro-organisms of the tongue may be of influence on the flora of the entire oral cavity. The normal appearance of the dorsum of the tongue is either pinkish or has a thin white coating. For the present study a scoring method was developed to describe the appearance of the dorsum of the tongue in relation to the extent of color and thickness of tongue coating. Aim The purpose of this study was to investigate the discoloration and coating of the tongue in healthy/gingivitis subjects and periodontitis patients. Furthermore, to determine the relationship between the appearance of the tongue and the bacterial load in salivary samples. Material and methods 2 groups of patients were studied, 70 healthy/gingivitis subjects and 56 periodontitis patients. After scoring of the tongue a salivary sample of each patient was taken and analyzed using a phase-contrast microscope. Results This investigation showed that most discoloration was found on the distal part of the tongue. The mean number of bacteria per ml sample in relation to a pink, white and yellow appearance of the tongue was 948, 855 and 900 (x 10(6)) respectively. The mean number of bacteria per ml sample in relation to no, thin and thick coating was 948, 863, and 895 (x 10(6)), respectively. Analysis did not reveal a relationship between discoloration, coating thickness and total bacterial load. The mean number of bacteria per ml in healthy/gingivitis subjects was 860 and in periodontitis patients 918 (x 10(6)). Conclusion No relationship between the appearance of the tongue and salivary bacterial load could be detected. There was no difference in bacterial load between the healthy/gingivitis and the periodontitis group within the present study population.

Periodontal Bacteria Colonizing Oral Mucous Membranes in Edentulous Patients Wearing Dental Implants

Abstract: The purpose of this study was to investigate the prevalence of the microbiota on the oral mucosal surfaces and in the peri-implant pocket in edentulous subjects with a past history of periodontitis. Twenty edentulous subjects wearing dental implants for at least one year and with a history of periodontitis participated in this study. Clinical parameters were assessed (plaque, redness, swelling, peri-implant probing depth [PIPD], and bleeding on probing) and microbiological samples were taken (oral mucosal surfaces, saliva, plaque, and peri-implant pocket). Based on the clinical results, the group as a whole showed healthy peri-implant tissues. A mean PIPD of 3.6 mm was found. A statistically significant correlation was found between the PIPD and bleeding upon probing, plaque scores, redness, and swelling. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were not detected. The subjects harboring Prevotella intermedia showed presence of PIPD of > or = 5 mm. All subjects harbored Peptostreptococcus spp., Fusobacterium spp., and other Prevotella species. Actinomyces odontolyticus, Bacteroides forsythus, Campylobacter rectus, Pseudomonas spp., and enterobacteria were detected less frequently. Three subjects showed signs of overt soft tissue inflammation. They harbored higher proportions of Peptostreptococcus spp. than the other subjects. The results corroborate the suggestion that the primary source of colonization for dental implants in edentulous patients are the oral mucous membranes. The results indicate that the microbiota of subjects wearing dental implants with a past history of periodontitis are composed of bacteria associated with a healthy periodontium or gingivitis. It is suggested that elimination of the subgingival environment by extraction of all natural teeth probably initiates the disappearance of the two periodontal bacteria A. actinomycetemcomitans and P. gingivalis.

Tongue coating and tongue brushing: a literature review.

Abstract: The present paper reviews the role of the tongue as a habitat for oral microorganisms and the potential need for tongue cleaning as part of daily oral hygiene. In addition tongue coating is described. Many microorganisms have been found colonizing the dorsum of the tongue. Some studies find a positive effect to tongue brushing on bacterial counts on the tongue. On the other hand there are also studies that do not find any differences in bacterial counts before or after tongue brushing. Bacteria colonizing the tongue and periodontal pockets play an important role in the production of volatile sulphur compounds in periodontal health and disease. These compounds can be the cause of oral malodour. The amount of tongue coating in patients complaining of halitosis was significantly greater than in patients without halitosis. Tongue brushing on a regular basis, particular aiming at removing the coating on the dorsum of the tongue, has been found to be fruitful in reducing oral malodour. Studies investigating the role of tongue brushing and plaque accumulation or gingival inflammation show conflicting results. It is clear that the tongue forms the largest niche for microorganims in the oral cavity. However, on the basis of literature, there appears to be no data to justify the necessity to clean the tongue on a regular basis. One exception would be oral malodour.

The long-term effect of an oscillating/rotating electric toothbrush on gingivitis. An 8-month clinical study.

Abstract: The purpose of this study was to evaluate the safety and efficacy of the Braun Plak Control® for the removal of supragingival plaque and improving gingival health in a long-term clinical trial, and to compare it to a regular manual toothbrush. Assessed were plaque accumulation, amount of gingival inflammation, gingival bleeding on probing, and calculus. In total, 77 young individuals were selected on the basis of having moderate gingivitis'. They were monitored over 8 months and divided among 2 groups; a control group that used a manual toothbrush and a test group that used the Braun Plak Control. The clinical assessments were repeated after 1, 2, 5, and 8 months. At baseline, subjects were handed their assigned toothbrushes together with written oral hygiene instructions. They were instructed to brush for at least 2 min. 1 month after baseline examinations, all subjects received a professional prophylaxis and oral hygiene instruction from an experienced dental hygienist. Plaque removal was reinforced at the 2- and 5-month examination. In conclusion, results indicate that the Braun Plak Control is a safe and efficient home care device. At the end of this trial, this electric toothbrush proved to be more effective than a regular manual tooth brush.

Periodontal microbial ecology.

Abstract: The authors have taken the liberty of presenting this manuscript in two parts. The first is a brief primer on microbial ecology, because, although the importance of microbial ecology in periodontal diseases is widely recognized, most of us do not know precisely what is meant by the term. The second section is a rather extensive overview of current studies of oral microbial ecology based almost entirely on recent in vivo studies.

Effect of material characteristics and/or surface topography on biofilm development

Abstract: Background: From an ecological viewpoint, the oral cavity, in fact the oro-pharynx, is an ‘open growth system’. It undergoes an uninterrupted introduction and removal of both microorganisms and nutrients. In order to survive within the oro-pharyngeal area, bacteria need to adhere either to the soft or hard tissues in order to resist shear forces. The fast turn-over of the oral lining epithelia (shedding 3 ×/day) is an efficient defence mechanism as it prevents the accumulation of large masses of microorganisms. Teeth, dentures, or endosseous implants, however, providing non-shedding surfaces, allow the formation of thick biofilms. In general, the established biofilm maintains an equilibrium with the host. An uncontrolled accumulation and/or metabolism of bacteria on the hard surfaces forms, however, the primary cause of dental caries, gingivitis, periodontitis, peri-implantitis, and stomatitis. Objectives: This systematic review aimed to evaluate critically the impact of surface characteristics (free energy, roughness, chemistry) on the de novo biofilm formation, especially in the supragingival and to a lesser extent in the subgingival areas. Methods: An electronic Medline search (from 1966 until July 2005) was conducted applying the following search items: ‘biofilm formation and dental/oral implants/surface characteristics’, ‘surface characteristics and implants’, ‘biofilm formation and oral’, ‘plaque/biofilm and roughness’, ‘plaque/biofilm and surface free energy’, and ‘plaque formation and implants’. Only clinical studies within the oro-pharyngeal area were included. Results: From a series of split-mouth studies, it could be concluded that both an increase in surface roughness above the Ra threshold of 0.2 μm and/or of the surface-free energy facilitates biofilm formation on restorative materials. When both surface characteristics interact with each other, surface roughness was found to be predominant. The biofilm formation is also influenced by the type (chemical composition) of biomaterial or the type of coating. Direct comparisons in biofilm formation on different transmucosal implant surfaces are scars. Conclusions: Extrapolation of data from studies on different restorative materials seems to indicate that transmucosal implant surfaces with a higher surface roughness/surface free energy facilitate biofilm formation.

Infectious risks for oral implants: a review of the literature

Abstract: The use of oral implants in the rehabilitation of partially and fully edentulous patients is widely accepted even though failures do occur. The chance for implants to integrate can for example be jeopardised by the intra-oral presence of bacteria and concomitant inflammatory reactions. The longevity of osseointegrated implants can be compromised by occlusal overload and/or plaque-induced peri-implantitis, depending on the implant geometry and surface characteristics. Animal studies, cross-sectional and longitudinal observations in man, as well as association studies indicate that peri-implantitis is characterised by a microbiota comparable to that of periodontitis (high proportion of anaerobic Gram-negative rods, motile organisms and spirochetes), but this does not necessarily prove a causal relationship. However, in order to prevent such a bacterial shift, the following measures can be considered: periodontal health in the remaining dentition (to prevent bacterial translocation), the avoidance of deepened peri-implant pockets, and the use of a relatively smooth abutment and implant surface. Finally, periodontitis enhancing factors such as smoking and poor oral hygiene also increase the risk for peri-implantitis. Whether the susceptibility for periodontitis is related to that for peri-implantitis may vary according to the implant type and especially its surface topography.