Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where William Papaioannou is active.

Publication


Featured researches published by William Papaioannou.


Oral Microbiology and Immunology | 2009

The microbiota on different oral surfaces in healthy children

William Papaioannou; Sotiria Gizani; Anne D. Haffajee; Marc Quirynen; E Mamai-Homata; L. Papagiannoulis

INTRODUCTION Knowledge of the early oral colonization patterns could provide a better understanding of oral biofilm development and disease initiation that in turn could be the basis for early preventive programmes. METHODS Microbial samples were collected from five different oral habitats from a total of 93 children (age 3-12 years), attending the Dental School of the University of Athens, who were split into three age groups. A total of 38 microbial species were sought out by the checkerboard DNA-DNA hybridization technique. RESULTS All of the test species, except Parvimonas micra and Porphyromonas gingivalis, differed significantly among sample locations providing quite distinct microbial profiles for the different oral surfaces. Supragingival and subgingival plaque had similar profiles and exhibited higher proportions of Actinomyces species and Green complex while soft tissue samples were dominated by streptococci of the Yellow complex. The profiles of the tongue dorsum and saliva were also similar. Many of the species were in similar proportions in all three age groups for a given location. Periodontal pathogens showed increases in proportions with increasing age. Specifically, the Red complex species (Tannerella forsythia, P. gingivalis, Treponema denticola) showed a significant increase in proportion with age (P < 0.05) in all sample locations. CONCLUSIONS The results showed a pattern of colonization in children similar to that previously found in adults. Differences in the profile between age groups suggest a gradual maturation of the oral microbiota, with it being made up of an increasing number of Orange and Red complex species.


Angle Orthodontist | 2007

Adhesion of Streptococcus mutans to Different Types of Brackets

William Papaioannou; Sotiria Gizani; Maria Nassika; Efterpi Kontou; Melachrini Nakou

OBJECTIVE To examine the difference in the adhesion of Streptococcus mutans to three different types of orthodontic brackets and the effect of the presence of an early salivary pellicle and Streptococcus sanguis on adhesion. MATERIALS AND METHODS Three adhesion experiments were performed using stainless steel, ceramic, and plastic orthodontic brackets. In the first experiment a clinical strain of S mutans adhered to the three different types of brackets (n = 6 for each). For the second, the brackets were treated with saliva before adhesion of S mutans (n = 6 per type of bracket). Finally, the third experiment concerned saliva coated brackets (n = 6 per type of bracket), but before S mutans, S sanguis bacteria were allowed to adhere. The bacteria were always allowed to adhere for 90 minutes in all the experiments. Adhesion was quantitated by a microbial culture technique by treating the brackets with adhering bacteria with trypsin and enumerating the total viable counts of bacteria recovered after cultivation. RESULTS There were consistently no differences in the adherence to stainless steel, ceramic, or plastic brackets. The presence of an early salivary pellicle and S sanguis reduced the number of adhering S mutans to all three types of brackets. CONCLUSIONS Adhesion of bacteria to orthodontic brackets depends on several factors. The presence of a salivary pellicle and other bacterial species seem to have a significant effect on the adhesion of S mutans, reducing their numbers and further limiting any differences between types of brackets.


European Journal of Orthodontics | 2010

Salivary Streptococcus mutans levels in patients with conventional and self-ligating brackets

Nikolaos Pandis; William Papaioannou; Efterpi Kontou; Melachrini Nakou; Margarita Makou; Theodore Eliades

The objective of this study was to investigate the effect of bracket type (conventional and self-ligating) on the levels of Streptococcus mutans and total bacterial counts in whole saliva of orthodontic patients. Thirty-two male and female patients were selected using the following inclusion criteria: adolescents (mean age 13.6 years, range 11-17 years), fixed appliances in both arches, non-smoker, and no reported oral habits. Demographic and oral hygiene characteristics were determined for each subject. The patients were subdivided into two groups with random allocation of bracket type (conventional or self-ligating). An initial saliva sample was obtained before the initiation of treatment (T1) and a second sample 2-3 months following appliance bonding (T2). Salivary S. mutans and total bacteria were enumerated and analysed after growth in culture. The demographic and clinical characteristics of the samples were analysed with a t- or chi-square test, where applicable, to assess the random allocation of bracket group to participants. The results of S. mutans and total facultative bacterial counts were log transformed and statistically analysed with analysis of covariance with bracket (conventional versus self-ligating) as the categorical variable and initial total bacterial counts or initial S. mutans levels serving as the covariate. No difference was found in the demographics and oral hygiene indices between the two groups, verifying the random assignment of brackets to the population sample. The levels of S. mutans in whole saliva of orthodontically treated patients do not seem to be significantly different between conventional and self-ligating brackets. The pre-treatment levels of S. mutans are significant predictors of the levels of S. mutans after placement of orthodontic appliances, while this was not the case for total bacterial counts.


International Journal of Paediatric Dentistry | 2009

Distribution of selected cariogenic bacteria in five different intra-oral habitats in young children.

Sotiria Gizani; William Papaioannou; Anne D. Haffajee; Katerina Kavvadia; Marc Quirynen; L. Papagiannoulis

BACKGROUND Knowledge of the colonization patterns and composition of the oral microbiota can lead to a better understanding of disease initiation. AIM The aim of this study was to examine the distribution of selected cariogenic bacteria in samples from five different oral habitats in young Greek children. DESIGN Ninety-three children 3-12 years old (mean + SD 7.9 +/- 2.5) (60.2% male, 39.8% female) participated and split into three different age groups: primary (3-6 years), early mixed (6-9 years), and mixed dentition (9-12 years). Samples for bacterial enumeration were taken from saliva, supragingival and subgingival plaque, tongue dorsum, and soft tissues from each child, and were further analysed using checkerboard DNA-DNA hybridization. RESULTS Mean counts and proportions of all the test bacteria differed significantly among sample locations. Cariogenic bacteria were present in almost all healthy children. Mean proportions of Streptococcus mutans isolated from soft tissue and Streptococcus sanguinis from soft tissue, subgingival and saliva samples increased significantly with age, whereas the opposite was seen for Lactobacillus acidophilus. CONCLUSIONS Cariogenic bacteria were present in almost all young children. Soft tissues, saliva, and tongue were more often colonized by cariogenic streptococcal species than teeth. These surfaces may serve as reservoirs for oral pathogens, requiring attention during preventive interventions.


Health and Quality of Life Outcomes | 2012

Validation of a Greek version of the oral health impact profile (OHIP-14) for use among adults

Vassilia Papagiannopoulou; Constantine Oulis; William Papaioannou; George Antonogeorgos; John Yfantopoulos

BackgroundTo test the validity of the short form of the Oral Health Impact Profile (OHIP-14) for use among adults in Greece.MethodsThe original English version of the OHIP-14 was translated using the forward-backward technique, pilot-tested, and then applied to 211 adults aged 35 years and above. The questionnaire was filled out during face-to-face interviews conducted by one dentist, while individuals were asked to undergo a clinical examination. The internal consistency of the questionnaire was evaluated using Cronbachs alpha (α) coefficient and inter-item and item-total correlations. Discriminant and convergent validities were assessed.ResultsCronbachs α was estimated to be 0.90. Inter-item correlations coefficients ranged from 0.10 to 0.83, while item-total correlations coefficients from 0.44 to 0.76. Significant associations were found between OHIP-14 and the decayed, missing and filled teeth (DMFT) and oral hygiene, supporting the ability of the questionnaire to discriminate between individuals with and without impacts. The OHIP-14 total score was highly associated with self-perceived oral health status (rs = 0.57; p = 0.01), as well as with self-assessment of oral satisfaction (rs = 0.55;p = 0.01). Similar results were observed by investigating the relationship between the latter questions and each domain score as well as in various sub-groups analyses.ConclusionsThe OHIP-14 is a reliable and valid questionnaire for the assessment of OHRQoL among adults in Greece.


International Dental Journal | 2013

Prevalence of dental caries in 5‐year‐old Greek children and the use of dental services: evaluation of socioeconomic, behavioural factors and living conditions

Magdalini Mantonanaki; Haroula Koletsi-Kounari; Eleni Mamai-Homata; William Papaioannou

OBJECTIVES To assess dental caries and use of dental services experience in 5-year-old children attending public kindergartens in Attica, Greece and to examine the influence of certain socioeconomic factors and living conditions as well as dental behaviours and attitudes. METHODS In this cross-sectional study, a random and stratified sample of 605 Greek children was examined using decayed, missing, filled tooth surfaces and simplified debris indices. The use of dental services was measured by childrens dental visits (any dental visit up to the age of 5 years). Care Index was also calculated. Risk indicators were assessed by a questionnaire. Zero-inflated Poisson and Logistic Regression Analysis were generated to test statistical significant associations. RESULTS The prevalence of dental caries was 16.5%. Care Index was 32% and dental visits were reported for the 84% of the children. Medium Socio-Economic Level (SEL) was associated with no detectable caries. High SEL was related to decreased decayed, missing, filled teeth values, while female gender and rented houses had the opposite effect. The age of the mother (35-39 years) and the higher SEL were related to higher levels of dental services use. CONCLUSIONS It is suggested that there are differences in the experience of dental caries and use of dental services among preschool children in Attica, which are related to demographic, socioeconomic factors and living conditions. Dental public polices should focus on groups with specific characteristics in order to improve oral health levels of disease-susceptible populations.


International Journal of Paediatric Dentistry | 2009

Periodontal and microbiological parameters in children and adolescents with cleft lip and /or palate

Hariklia Perdikogianni; William Papaioannou; Melachrini Nakou; Constantine Oulis; L. Papagiannoulis

Objective. To evaluate the oral hygiene and the periodontal condition of children and adolescents with cleft lip and/or palate (CLP). Methods. Forty-one children and adolescents, 4-18 years, with CLP and 41 normal controls participated. Clinical parameters examined were the plaque and gingival index and Community Periodontal Index of Treatment Needs. For teeth in the cleft area, probing pocket depth, bleeding on probing, and tooth mobility were also evaluated. Samples of subgingival plaque were collected from 21 randomly selected patients of each group. Results. The CLP group had generally poorer oral hygiene (plaque index significantly higher) compared with the control. Children in both groups presented mild degree of gingivitis. Teeth in the cleft area had significantly higher pocket probing depth and tooth mobility, compared with corresponding teeth in the control group. The microbial analysis did not reveal significant differences in the composition of the subgingival microbiota between groups. Teeth in the cleft presented higher isolation frequencies and mean percentages of periodontopathic bacteria. Conclusion. Youngsters with CLP showed poor oral hygiene and worse periodontal condition, compared with controls. The above results advocate their participation in an intensive preventive dental programme that should start at an early age, possibly decreasing the risk of future periodontal disease.


European Archives of Paediatric Dentistry | 2011

Oral health related quality of life of Greek adolescents: a cross-sectional study.

William Papaioannou; Constantine Oulis; D. Latsou; John Yfantopoulos

AIM: To investigate the impact of oral health status on the quality of life of a cross-section of adolescents belonging to different population groups in different regions of Greece, using the Oral Health Impact Profile-short form (OHIP-14), one of the most widely known instruments used for the measurement of disability and discomfort due to oral conditions. METHODS: A random sample consisting of a total of 515 Greek adolescents between the ages of 15–18 years (mean 16.1±0.9) were selected from different urban and rural areas according to the last census. A self-administrated questionnaire was designed including the OHIP-14 validated for the Greek language, and face-to-face interviews were conducted by one dentist trained in oral health related quality of life (OHRQoL) terms. Associations of the total OHIP-14 score and its seven sub-scales along with the self-perceived quality of life were evaluated with Spearman correlations. RESULTS: Internal reliability returned a very good internal consistency with a Cronbach alpha of 0.86. The subjects had an overall weighted OHIP-14 score of 1.24 (SD 2.04) meaning that there was an impact of oral health on the overall quality of life. Five of the seven subscales of the OHIP-14 tool were found to have significant correlations for the inhabitants of the different areas. Specifically, important and significant correlations were noted for functional limitation (p<0.01), handicap (p<0.05) and social disability (p<0.01) both for the metropolitan/non-metropolitan as well as the urban rural distinction. No correlations were found between the OHIP-14 scores, or of any of its sub-scales, with the parental education level and occupation. When self-assessed oral and general health statuses were considered to be ‘bad’ the OHIP-14 returned increased scores. CONCLUSIONS: Dental and oral health conditions are factors that do impact on the quality of life of adolescents.


Clinical Oral Investigations | 2002

Contamination of interdental brushes by periodontopathogens

William Papaioannou; V. Panis; M. Nakou; Z. Mantzavinos

Abstract.Experimental studies have shown that intraoral transmission of bacteria can occur. Of course, the question arises as to how this transmission may happen. In this study, the contamination of interdental brushes by periodontopathogens is examined and compared to the microbial load of the periodontal pockets. In ten untreated chronic periodontitis patients, four interdental sites were professionally brushed with one interdental brush per patient. Subsequently, samples from the depths of the pockets (of the specific interdental sites) were obtained with paper-points. The interdental brush samples and the samples of the subgingival plaque, obtained by the pooled paper-points, were processed for dark-field microscopy examination as well as anaerobic culturing. The results showed that, although significant differences could be found between the brushes and paper-points with direct microscopy, the culturing did not uncover many differences. On the contrary, the detection frequencies of specific bacterial species were almost the same between the two. The total anaerobic colony-forming units (CFU), P. gingivalis, F. nucleatum, and E. corrodens found on the brushes showed a significant correlation with the subgingival plaque samples (P<0.005). These results suggest that, in untreated situations, interdental brushes are contaminated relatively easily by putative periodontopathogens in numbers comparable to their presence in periodontal pockets. This contamination could be a factor in the intraoral spread of bacteria.


Journal of Clinical Periodontology | 2016

EFP Delphi study on the trends in Periodontology and Periodontics in Europe for the year 2025

Phoebus N. Madianos; William Papaioannou; David Herrera; Mariano Sanz; Amelie Baeumer; Anna Bogren; Philippe Bouchard; Maria Chomyszyn-Gajewska; Korkud Demirel; Rok Gašperšič; Marina Giurgiu; Filippo Graziani; Karin Jepsen; Søren Jepsen; Tiernan O′Brien; Ioannis Polyzois; Philip M. Preshaw; Mia Rakic; Michele Reners; Nives Rincic; Andreas Stavropoulos; Serdar Sütcü; Christian Verner; Juan Carlos Llodra

AIM The aim was to assess the potential trends in Periodontology and Periodontics in Europe that might be anticipated by the year 2025, using the Delphi method. MATERIAL AND METHODS The expert opinion of 120 experts was sought through the use of an open-ended questionnaire, developed by an advisory group, containing 40 questions concerning the various trends in periodontology. RESULTS The experts (113 responders) expect a stabilization of the prevalence of periodontitis, both for the chronic as well as the aggressive cases, but an increase in implant-related diseases up to the year 2025. Concurrently, the importance of implants is seen to be increasing. They foresee an increased demand for postgraduate periodontology and implantology training. This is mirrored in an increase in publications for implant dentistry and increase in demand and need for training. Concerning the patients, better-informed individuals seeking more routine check-ups are expected. CONCLUSION A continued need for specialized periodontists, but also well trained dental practitioners is foreseen for next decade in Europe. Apart from periodontology they will be increasingly exposed to and trained in implant dentistry.

Collaboration


Dive into the William Papaioannou's collaboration.

Top Co-Authors

Avatar

Constantine Oulis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Haroula Koletsi-Kounari

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

John Yfantopoulos

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Marc Quirynen

Katholieke Universiteit Leuven

View shared research outputs
Top Co-Authors

Avatar

Eleni Mamai-Homata

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

L. Papagiannoulis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Melachrini Nakou

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Sotiria Gizani

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Magdalini Mantonanaki

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Margarita Makou

National and Kapodistrian University of Athens

View shared research outputs
Researchain Logo
Decentralizing Knowledge