G.A. van der Weijden

Bio: G.A. van der Weijden is an academic researcher from Academic Center for Dentistry Amsterdam. The author has contributed to research in topics: Gingivitis & Dental Plaque Index. The author has an hindex of 46, co-authored 188 publications receiving 6720 citations. Previous affiliations of G.A. van der Weijden include VU University Amsterdam & Radboud University Nijmegen Medical Centre.

A systematic review on the clinical efficacy of subgingival debridement in the treatment of chronic periodontitis

Abstract: Objective: The purpose of this study was to perform a systematic review of the literature and to evaluate, in patients with chronic periodontitis, what the effect is of subgingival debridement (SGD), in terms of bleeding on probing, pocket depth and probing attachment level. Material and methods: An electronic search of the Cochrane Oral Health Group specialized register and MEDLINE were performed using specific search terms to identify studies assessing in patients with chronic periodontitis the effect of subgingival debridement with regard to clinical outcomes. This was performed on titles registered up to 2001. The only papers included were those which utilized data based on the patient as unit of observation. Results: The searches identified 702 abstracts. Titles and abstracts were independently screened by two reviewers (G.A.W. & M.F.T.) to identify publications that met specific inclusion criteria. The agreement between the two reviewers was assessed. The kappa score for agreement was 0.80. Review of these abstracts resulted in 114 publications for detailed review. Finally, 26 papers which met the criteria of eligibility were independently selected by the two reviewers. The kappa score for agreement on this decision was 0.92. Disagreement regarding inclusion of both abstracts and full papers was resolved by discussion between the reviewers. No randomized controlled trials (RCT) could be retrieved that were specifically designed to answer the question formulated at the outset of this systematic review. From the 10 controlled studies, four provide a definitive ‘yes’ that SGD is effective with regard to clinical outcomes. In the one study where subgingival debridement was not supported by oral hygiene instruction, the paper provided a definitive ‘no’. The weighted mean of attachment gain of SGD in pockets initially ≥5 mm was 0.64 mm as compared with 0.37 mm for supragingival plaque control only (SPC). The reduction of pocket depth was 0.59 mm and 1.18 mm for SPC and SGD, respectively. Of the 18 papers that provided only information on the effect of treatment as compared with the baseline values, eight showed SGD to be beneficial with regard to clinical attachment level change while the remaining 10 provided no such an analysis. The weighted mean of this effect was a 0.74-mm gain of attachment as a result of treatment in pockets initially ≥ 4 mm. Conclusions: In patients with chronic periodontitis, subgingival debridement (in conjunction with supragingival plaque control) is an effective treatment in reducing probing pocket depth and improving the clinical attachment level. In fact it is more effective than supragingival plaque control alone.

Effect of socket preservation therapies following tooth extraction in non-molar regions in humans: a systematic review.

Abstract: Objective: To assess, based on the existing literature, the benefit of socket preservation therapies in patients with a tooth extraction in the anterior or premolar region as compared with no additional treatment with respect to bone level. Material and methods: MEDLINE-PubMed and the Cochrane Central Register of controlled trials (CENTRAL) were searched till June 2010 for appropriate studies, which reported data concerning the dimensional changes in alveolar height and width after tooth extraction with or without additional treatment like bonefillers, collagen, growth factors or membranes. Results: Independent screening of the titles and abstracts of 1918 MEDLINE-PubMed and 163 Cochrane papers resulted in nine publications that met the eligibility criteria. In natural healing after extraction, a reduction in width ranging between 2.6 and 4.6 mm and in height between 0.4 and 3.9 mm was observed. With respect to socket preservation, the freeze-dried bone allograft group performed best with a gain in height, however, concurrent with a loss in width of 1.2 mm. Conclusion: Data concerning socket preservation therapies in humans are scarce, which does not allow any firm conclusions. Socket preservation may aid in reducing the bone dimensional changes following tooth extraction. However, they do not prevent bone resorption because, depending on the technique, on the basis of the included papers one may still expect a loss in width and in height.

A systematic review of the effectiveness of self‐performed mechanical plaque removal in adults with gingivitis using a manual toothbrush

Abstract: Objective: To assess the effectiveness of self-performed mechanical plaque removal in adults with gingivitis using a manual toothbrush with respect to the level of plaque and gingivitis in controlled studies of at least 6 months duration. Search: Medline-PubMed up to and including September 2004. Results: Out of 3223 titles and abstracts, 33 trials were found for data extraction. A meta-analysis was conducted of studies (n=9) in which, for the manual toothbrush group at baseline, only a professional prophylaxis provided. The weighted mean differences (WMD) between baseline and end-trial for the Quigley & Hein plaque index was 0.28 and 0.21 for the Gingival Index (p<0.05). Eight studies provided both a professional OHI and prophylaxis at baseline. The WMD for the Silness & Loe Plaque Index was 0.10 (ns). The WMD of the proportion of bleeding sites was 5.84% (p<0.05). Conclusion: In adults with gingivitis the quality of self-performed mechanical plaque removal is not sufficiently effective and should be improved. Based on studies 6 months of duration, it appears that a single oral hygiene instruction, describing the use of a mechanical toothbrush, in addition to a single professional ‘oral prophylaxis’ provided at baseline, had a significant, albeit small, positive effect on the reduction of gingivitis.

Amoxicillin plus metronidazole in the treatment of adult periodontitis patients: A double-blind placebo-controlled study

Abstract: Background, aims: The aim of this double-blind, parallel study was to evaluate the adjunctive effects of systemically administered amoxicillin and metronidazole in a group of adult periodontitis patients who also received supra- and subgingival debridement. Methods: 49 patients with a diagnosis of generalised severe periodontitis participated in the study. Random assignment resulted in 26 patients in the placebo (P) group with a mean age of 40 years and 23 patients in the test (T) group which had a mean age of 45 years. Clinical measurements and microbiological assessments were taken at baseline and 3 months after completion of initial periodontal therapy with additional placebo or antibiotic treatment. Patients received coded study medication of either 375 mg amoxicillin in combination with 250 mg metronidazole or identical placebo tablets, every 8 hours for the following 7 days. Results: At baseline, no statistically significant differences between groups were found for any of the clinical parameters. Except for the plaque, there was a significantly larger change in the bleeding, probing pocket depth (PPD) and clinical attachment level (CAL) in the T-group as compared to the P-group after therapy. The greatest reduction in PPD was found at sites with initial PPD of greater than or equal to7 mm, 2.5 mm in the P-group and 3.2 mm in the T-group. The improvement in CAL was most pronounced in the PPD category greater than or equal to7 mm and amounted to 1.5 mm and 2.0 mm in the P- and T-groups, respectively. No significant decrease was found in the number of patients positive for any of the test species in the P-group. The number of patients positive for Porphyromonas gingivalis. Bacteroides forsythus and Prevotella intermedia in the T-group showed a significant decrease. After therapy there was a significant difference between the P- and the T- group in the remaining number of patients positive for P. gingivalis. B. forsythus and Peptostreptococcus micros. 4 subgroups were created on the basis of the initial microbiological status for P. gingivalis positive (Pg-pos) and negative patients (Pg-neg) in the P- and the T-groups. The difference in reduction of PPD between Pg-pos and Pg-neg patients was particularly evident with respect to the changes in % of sites with a probing pocket depth greater than or equal to5 mm. This % decreased from 45% at baseline to 23% after treatment in the Pg-pos placebo subgroup and decreased from 46% to 11% in the Pg-pos test subgroup (p less than or equal to0.005). In contrast, the changes in the proportions of sites with a probing pocket depth greater than or equal to5 mm in the Pg-neg placebo and Pg-neg test subgroup were similar, from 43% at baseline to 18% after treatment versus 40% to 12%, respectively. Conclusions: This study has shown that systemic usage of metronidazole and amoxicillin. when used in conjunction with initial periodontal treatment in adult periodontitis patients, achieves significantly better clinical and microbiological results than initial periodontal treatment alone. Moreover, this research suggests that especially patients diagnosed with P. gingivalis benefit from antibiotic treatment.

Java project on periodontal diseases. The natural development of periodontitis: risk factors, risk predictors and risk determinants.

Abstract: Objective: To identify risk factors, risk predictors and risk determinants for onset and progression of periodontitis. Material and Methods: For this longitudinal, prospective study all subjects in the age range 15-25 years living in a village of approximately 2000 inhabitants at a tea estate on Western Java, Indonesia, were selected. Baseline examination was carried out in 1987 and follow-up examinations in 1994 and 2002. In 2002, 128 subjects could be retrieved from the original group of 255. Baseline examination included evaluation of plaque, bleeding on probing, calculus, pocket depth, attachment loss and presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, spirochetes and motile microorganisms. Results: The mean attachment loss increased from 0.33 mm in 1987 to 0.72 mm in 1994 and 1.97 mm in 2002. Analysis identified the amount of subgingival calculus and subgingival presence of A. actinomycetemcomitans as risk factors, and age as a risk determinant, for the onset of disease. Regarding disease progression, the number of sites with a probing depth >= 5 mm and the number of sites with recession were identified as risk predictors and male gender as a risk determinant. Conclusion: Screening of these parameters early in life could be helpful in the prevention of onset and progression of periodontal diseases.

Development of a Classification System for Periodontal Diseases and Conditions

Abstract: Classification systems are necessary in order to provide a framework in which to scientifically study the etiology, pathogenesis, and treatment of diseases in an orderly fashion. In addition, such systems give clinicians a way to organize the health care needs of their patients. The last time scientists and clinicians in the field of periodontology and related areas agreed upon a classi- fication system for periodontal diseases was in 1989 at the World Workshop in Clinical Periodontics.1 Subsequently, a simpler classification was agreed upon at the 1st European Workshop in Periodontology.2 These classification systems have been widely used by clinicians and research scientists throughout the world. Unfortunately, the 1989 classification had many shortcomings including: 1) considerable overlap in disease categories, 2) absence of a gingival disease component, 3) inappropriate emphasis on age of onset of disease and rates of progression, and 4) inadequate or unclear classification criteria. The 1993 Europea...

A new classification scheme for periodontal and peri-implant diseases and conditions - Introduction and key changes from the 1999 classification.

Abstract: A classification scheme for periodontal and peri-implant diseases and conditions is necessary for clinicians to properly diagnose and treat patients as well as for scientists to investigate etiology, pathogenesis, natural history, and treatment of the diseases and conditions. This paper summarizes the proceedings of the World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. The workshop was co-sponsored by the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP) and included expert participants from all over the world. Planning for the conference, which was held in Chicago on November 9 to 11, 2017, began in early 2015. An organizing committee from the AAP and EFP commissioned 19 review papers and four consensus reports covering relevant areas in periodontology and implant dentistry. The authors were charged with updating the 1999 classification of periodontal diseases and conditions and developing a similar scheme for peri-implant diseases and conditions. Reviewers and workgroups were also asked to establish pertinent case definitions and to provide diagnostic criteria to aid clinicians in the use of the new classification. All findings and recommendations of the workshop were agreed to by consensus. This introductory paper presents an overview for the new classification of periodontal and peri-implant diseases and conditions, along with a condensed scheme for each of four workgroup sections, but readers are directed to the pertinent consensus reports and review papers for a thorough discussion of the rationale, criteria, and interpretation of the proposed classification. Changes to the 1999 classification are highlighted and discussed. Although the intent of the workshop was to base classification on the strongest available scientific evidence, lower level evidence and expert opinion were inevitably used whenever sufficient research data were unavailable. The scope of this workshop was to align and update the classification scheme to the current understanding of periodontal and peri-implant diseases and conditions. This introductory overview presents the schematic tables for the new classification of periodontal and peri-implant diseases and conditions and briefly highlights changes made to the 1999 classification. It cannot present the wealth of information included in the reviews, case definition papers, and consensus reports that has guided the development of the new classification, and reference to the consensus and case definition papers is necessary to provide a thorough understanding of its use for either case management or scientific investigation. Therefore, it is strongly recommended that the reader use this overview as an introduction to these subjects. Accessing this publication online will allow the reader to use the links in this overview and the tables to view the source papers (Table 1).

Defining the healthy "core microbiome" of oral microbial communities

Abstract: Background: Most studies examining the commensal human oral microbiome are focused on disease or are limited in methodology. In order to diagnose and treat diseases at an early and reversible stage an indepth definition of health is indispensible. The aim of this study therefore was to define the healthy oral microbiome using recent advances in sequencing technology (454 pyrosequencing). Results: We sampled and sequenced microbiomes from several intraoral niches (dental surfaces, cheek, hard palate, tongue and saliva) in three healthy individuals. Within an individual oral cavity, we found over 3600 unique sequences, over 500 different OTUs or "species-level" phylotypes (sequences that clustered at 3% genetic difference) and 88 - 104 higher taxa (genus or more inclusive taxon). The predominant taxa belonged to Firmicutes (genus Streptococcus, family Veillonellaceae, genus Granulicatella), Proteobacteria (genus Neisseria, Haemophilus), Actinobacteria (genus Corynebacterium, Rothia, Actinomyces), Bacteroidetes (genus Prevotella, Capnocytophaga, Porphyromonas) and Fusobacteria (genus Fusobacterium). Each individual sample harboured on average 266 "species-level" phylotypes (SD 67; range 123 - 326) with cheek samples being the least diverse and the dental samples from approximal surfaces showing the highest diversity. Principal component analysis discriminated the profiles of the samples originating from shedding surfaces (mucosa of tongue, cheek and palate) from the samples that were obtained from solid surfaces (teeth). There was a large overlap in the higher taxa, "species-level" phylotypes and unique sequences among the three microbiomes: 84% of the higher taxa, 75% of the OTUs and 65% of the unique sequences were present in at least two of the three microbiomes. The three individuals shared 1660 of 6315 unique sequences. These 1660 sequences (the "core microbiome") contributed 66% of the reads. The overlapping OTUs contributed to 94% of the reads, while nearly all reads (99.8%) belonged to the shared higher taxa. Conclusions: We obtained the first insight into the diversity and uniqueness of individual oral microbiomes at a resolution of next-generation sequencing. We showed that a major proportion of bacterial sequences of unrelated healthy individuals is identical, supporting the concept of a core microbiome at health.

Cigarette smoking and infection.

Abstract: Background Infectious diseases may rival cancer, heart disease, and chronic lung disease as sources of morbidity and mortality from smoking. We reviewed mechanisms by which smoking increases the risk of infection and the epidemiology of smoking-related infection, and delineated implications of this increased risk of infection among cigarette smokers. Methods The MEDLINE database was searched for articles on the mechanisms and epidemiology of smoking-related infectious diseases. English-language articles and selected cross-references were included. Results Mechanisms by which smoking increases the risk of infections include structural changes in the respiratory tract and a decrease in immune response. Cigarette smoking is a substantial risk factor for important bacterial and viral infections. For example, smokers incur a 2- to 4-fold increased risk of invasive pneumococcal disease. Influenza risk is severalfold higher and is much more severe in smokers than nonsmokers. Perhaps the greatest public health impact of smoking on infection is the increased risk of tuberculosis, a particular problem in underdeveloped countries where smoking rates are increasing rapidly. Conclusions The clinical implications of our findings include emphasizing the importance of smoking cessation as part of the therapeutic plan for people with serious infectious diseases or periodontitis, and individuals who have positive results of tuberculin skin tests. Controlling exposure to secondhand cigarette smoke in children is important to reduce the risks of meningococcal disease and otitis media, and in adults to reduce the risk of influenza and meningococcal disease. Other recommendations include pneumococcal and influenza vaccine in all smokers and acyclovir treatment for varicella in smokers.

Peri-implant diseases: diagnosis and risk indicators

Abstract: Background: Peri-implant diseases include peri-implant mucositis, describing an inflammatory lesion of the peri-implant mucosa, and peri-implantitis, which also includes loss of supporting bone. Methods: A literature search of the Medline database (Ovid), up to 21 January 2008 was carried out using a systematic approach, in order to review the evidence for diagnosis and the risk indicators for peri-implant diseases. Results: Experimental and clinical studies have identified various diagnostic criteria including probing parameters, radiographic assessment and peri-implant crevicular fluid and saliva analyses. Cross-sectional analyses have investigated potential risk indicators for peri-implant disease including poor oral hygiene, smoking, history of periodontitis, diabetes, genetic traits, alcohol consumption and implant surface. There is evidence that probing using a light force (0.25 N) does not damage the peri-implant tissues and that bleeding on probing (BOP) indicates presence of inflammation in the peri-implant mucosa. The probing depth, the presence of BOP, and suppuration should be assessed regularly for the diagnosis of peri-implant diseases. Radiographs are required to evaluate supporting bone levels around implants. The review identified strong evidence that poor oral hygiene, a history of periodontitis and cigarette smoking, are risk indicators for peri-implant disease. Future prospective studies are required to confirm these factors as true risk factors.