U. Velden

Principles in prevention of periodontal diseases Consensus report of group 1 of the 11th European Workshop on Periodontology on effective prevention of periodontal and peri-implant diseases

AIMS In spite of the remarkable success of current preventive efforts, periodontitis remains one of the most prevalent diseases of mankind. The objective of this workshop was to review critical scientific evidence and develop recommendations to improve: (i) plaque control at the individual and population level (oral hygiene), (ii) control of risk factors, and (iii) delivery of preventive professional interventions. METHODS Discussions were informed by four systematic reviews covering aspects of professional mechanical plaque control, behavioural change interventions to improve self-performed oral hygiene and to control risk factors, and assessment of the risk profile of the individual patient. Recommendations were developed and graded using a modification of the GRADE system using evidence from the systematic reviews and expert opinion. RESULTS Key messages included: (i) an appropriate periodontal diagnosis is needed before submission of individuals to professional preventive measures and determines the selection of the type of preventive care; (ii) preventive measures are not sufficient for treatment of periodontitis; (iii) repeated and individualized oral hygiene instruction and professional mechanical plaque (and calculus) removal are important components of preventive programs; (iv) behavioural interventions to improve individual oral hygiene need to set specific Goals, incorporate Planning and Self monitoring (GPS approach); (v) brief interventions for risk factor control are key components of primary and secondary periodontal prevention; (vi) the Ask, Advise, Refer (AAR) approach is the minimum standard to be used in dental settings for all subjects consuming tobacco; (vii) validated periodontal risk assessment tools stratify patients in terms of risk of disease progression and tooth loss. CONCLUSIONS Consensus was reached on specific recommendations for the public, individual dental patients and oral health care professionals with regard to best action to improve efficacy of primary and secondary preventive measures. Some have implications for public health officials, payers and educators.

Periodontitis is associated with platelet activation

There is an epidemiological association between periodontitis and cardiovascular disease (CVD). In periodontitis, low grade systemic inflammation and bacteremia occur regularly. Such events may contribute to platelet activation and subsequent pro-coagulant state. This study aimed to investigate platelet activation in periodontitis patients. The study is composed of two parts. In the first part, plasma levels of soluble(s) P-selectin and sCD40 ligand were measured as general markers of platelet activation in periodontitis patients (n=85) and in healthy controls (n=35). In the second part, surface-exposed P-selectin and the ligand-binding conformation of the glycoprotein IIb-IIIa complex (binding of PAC-1 antibody) were determined on individual platelets in whole blood of periodontitis patients (n=18) and controls (n=16). Patients had significantly elevated plasma levels of sP-selectin (P<0.001) and increased binding of PAC-1 on isolated platelets (P=0.033). Platelet activation was more pronounced in the patients with more severe periodontal disease, showing a severity-dependence. The levels of sCD40 ligand and of platelet-bound P-selectin were not increased. Periodontitis is associated with increased platelet activation. Since platelet activation contributes to a pro-coagulant state and constitutes a risk for atherothrombosis, platelet activation in periodontitis may partly explain the epidemiological association between periodontitis and CVD.

Periodontal infection in cancer patients treated with high-dose chemotherapy

The infected and inflamed periodontium can act as a focus for systemic infection in neutropenic cancer patients. The incidence of these oral infections is unknown, but probably underestimated. Periodontal infections can easily be overlooked, primarily because symptoms of gingival inflammation may be minimal and the infection may be located in deeper parts of the periodontium. Assessment of a patients periodontal condition before the onset of profound neutropenia is critical to the diagnosis and the management of these potentially life-threatening infections. This review article is aimed at informing supportive care providers of recent insights into the pathogenesis of periodontal diseases and the role of subgingival microorganisms, with the emphasis on these infections in cancer patients treated with high-dose chemotherapy. Furthermore, a multidisciplinary approach to the management of periodontal infections and the need for future research is discussed.

Effect of surface topography of screw‐shaped titanium implants in humans on clinical and radiographic parameters: a 12‐year prospective study

OBJECTIVES Although implants with a roughened surface are widely used today, little is known about the long-term effect of a roughened surface compared with the conventional machined surface on clinical and radiographic parameters. The purpose of this study is to investigate the long-term differences between moderately rough (tioblasted) titanium implants and minimally rough machined/turned surfaces with respect to marginal bone resorption and the peri-implant soft tissues in the same patient. MATERIAL AND METHODS In 20 fully edentulous patients, with severely resorbed mandibles, a total of 80 Astra Tech dental implants were placed in the mandible to support a bar construction with a full overdenture. In each patient two minimally rough-surfaced (turned) and two moderately rough-surfaced (tioblast) implants were placed alternately. Clinical evaluation was carried out at base line (prosthetic installation), 6 months, 1, 2, 3, 4, 5 and 12 years. Radiographic evaluation using standardized individual filmholders was carried out at base line (prosthetic installation), 6 months, 1, 5 and 12 years. RESULTS In two patients, during the abutment surgery, one turned implant showed insufficient osseointegration and was replaced. One implant showed an abutment fracture after 9 years and was kept as a sleeper. From base line up to 12 years, no implant was lost. No significant differences were found between both implant surfaces concerning the clinical parameters such as plaque, calculus, bleeding and probing pocket depth. The mean (SD) marginal bone changes up to 12 years varied between -0.11 and +0.01 mm for the turned and -0.2 and +0.01 mm for the tioblast implants. No significant difference in marginal bone loss was found between both implant surfaces. CONCLUSION We conclude that after 12 years of follow-up, no differences could be found between the turned and the tioblasted implants, both for soft and for hard tissue parameters.

Polymorphisms in the interleukin-1 (IL1) gene cluster are not associated with aggressive periodontitis in a large Caucasian population

Polymorphisms in the interleukin-1 (IL1) gene have been suggested to influence transcription of IL1A (interleukin-1alpha) and IL1B (interleukin-1beta) and thereby the pathophysiology of periodontitis. This case-control association study on 415 northern European Caucasian patients with aggressive periodontitis (AgP) and 874 healthy controls was conducted to examine 10 single-nucleotide polymorphisms (SNPs) in the genes of the IL1 cluster for association with IL1A, IL1B, CKAP2L (cytoskeleton-associated protein 2-like), and IL1RN (IL-1 receptor antagonist). The results do not support an association between variants in the IL1 gene cluster and AgP. This case-control study had at least 95% power to detect genuine associations with variants carrying relative risks of at least 1.5 for heterozygous carriers and 2.25 for homozygous carriers. Previous reports of an association between IL1 promoter SNPs and periodontitis might reflect subpopulation effects and have to be interpreted with care.

Soluble CD14 in periodontitis

Lipopolysaccharide (LPS) binds to soluble (s)CD14. We investigated which factors contribute to variations in sCD14 levels in periodontitis, a chronic infectious disease of tooth-supporting tissues associated with endotoxemia and leading to inflammation and subsequently loss of teeth. The sCD14 levels were determined by ELISA in healthy controls (n = 57) and untreated patients (59 moderate and 46 severe) and their relation with markers of systemic inflammation (C-reactive protein levels, and leukocyte, neutrophil and lymphocyte counts) was assessed. Anti-Aggregatibacter actinomycetemcomitans and anti-Porphyromonas gingivalis IgG levels were established by ELISA and CD14-260 genotype was determined in a TaqMan allelic discrimination assay. Increased levels of sCD14 were more frequent among periodontitis patients (P = 0.026) and showed a severity-dependence with increasing levels of periodontal breakdown (P = 0.008). In patients, levels of sCD14 correlated positively with CRP (P = 0.043), leukocyte numbers (P = 0.011) and negatively with anti-A. actinomycetemcomitans IgG (P = 0.007). In a multivariate analysis, sCD14 levels were predicted by ethnicity, age, educational level, and in Caucasian subjects also by the severity of periodontal destruction, but not by anti-P. gingivalis IgG or the CD14-260 genotype. Periodontitis is associated with elevated levels of sCD14.

Java project on periodontal diseases: serotype distribution of Aggregatibacter actinomycetemcomitans and serotype dynamics over an 8‐year period

OBJECTIVE To investigate the serotype distribution and stability of Aggregatibacter actinomycetemcomitans over an 8-year period in untreated Indonesian subjects. MATERIAL AND METHODS Clinical periodontal status and the presence of A. actinomycetemcomitans were established in 1994 and 2002 in 107 subjects from an Indonesian tea estate deprived from dental care. On an average, 3.6 isolates per patient were subcultured and serotyped using specific PCR reactions. RESULTS In 1994, the predominant serotype was b (53.7%), whereas a and c occurred in 17.1% and 14.6% of the subjects, respectively. In 2002, a reduction in serotypes a (7.5%) and b (30.2%) occurred. Serotypes c and e increased in prevalence from 14.6% to 35.8% and 2.4% to 9.4%, respectively. Multiple serotypes were found in 12.2% in 1994 and 17% in 2002. From 24 subjects who were positive at both time points, 14 (58.3%) had the same serotype, whereas in 10 subjects (41.7%), a different serotype was found. Mean clinical attachment loss had increased from 0.74 mm in 1994 to 1.96 mm in 2002 but could not be related to subgingival presence of A. actinomycetemcomitans. CONCLUSIONS A. actinomycetemcomitans serotypes distribution in Indonesian young adults shifts from predominantly serotype b to a more equal prevalence of serotypes b and c. This shift suggests an opportunistic character of A. actinomycetemcomitans.

Mannose-binding lectin gene polymorphisms in relation to periodontitis

AIM To investigate the correlation of six functional polymorphisms in the MBL gene with MBL plasma levels in relation to periodontitis. MATERIAL AND METHODS A total of 92 periodontitis patients and 70 controls, all of Caucasian origin, were included. Patients and controls were genotyped for the L/H, X/Y, P/Q, A/D, A/B and A/C polymorphisms. Distributions of genotypes, rate of allele carriage and allele frequencies were compared between patients and controls. Patients and controls were subdivided in groups of genotypes. Plasma MBL levels were compared between different genotype groups. RESULTS On the basis of genotyping, three phenotypes with regard to mannose-binding lectin (MBL) production were distinguished: high-producers, low-producers and deficient subjects. No differences in the genotype frequencies were observed between patients and controls. Within patients and controls, subjects with the high-producing genotypes had significantly higher MBL plasma levels than low-producers and deficient subjects (p<0.001). Plasma MBL was higher in low-producer patients compared with low-producer controls (p(adjusted)=0.021). CONCLUSION No association could be observed between MBL gene polymorphisms and susceptibility to periodontitis in Caucasians. However, now that genotyping could distinguish the low producing and deficient subjects from the high-producers, it was observed, for the first time, that MBL acts as a weak acute-phase protein in periodontitis.

Clonal stability of Porphyromonas gingivalis in untreated periodontitis

OBJECTIVES The objective of the present investigation was to study the clonal stability of Porphyromonas gingivalis in a population of Indonesian subjects, deprived of dental care and with varying degrees of periodontitis over a period of 8 years. MATERIAL AND METHODS In 1994, 105 subjects and in 2002, 103 subjects were P. gingivalis culture positive. Multiple isolates from each of these subjects were used for amplified fragment length polymorphism (AFLP) typing. RESULTS Sixty-six individuals were P. gingivalis culture positive at both time points. In 31 subjects (47%) an exact identical P. gingivalis genotype distribution was found in 1994 and in 2002. In 26 of these subjects one genotype, in eight subjects two identical genotypes were found at both time points. In 70% of the subjects at least one P. gingivalis genotype was found in 1994 and 2002, whereas other genotypes were either newly detected or were no longer detectable. Identical genotypes were found in 26% of the sibships. Clonal stability in siblings was 39%. Horizontal transmission of P. gingivalis was only found in 2002 and was low (11%). In total, 56 P. gingivalis genotypes were identified in 1994 and 61 in 2002. Twenty-four appeared unique, whereas other genotypes were found in multiple subjects within as well as without families. One genotype occurred in 11 different subjects. CONCLUSIONS The clonal stability of P. gingivalis under natural conditions is high. Complete different genotype distribution was found in only 27% of the subjects. Transmission of P. gingivalis occurred frequently among siblings but not among spouses.

Adjunctive effect of a water-cooled Nd:YAG laser in the treatment of chronic periodontitis

OBJECTIVES To test whether use of a water-cooled Nd:YAG laser adjunctive to supra- and subgingival debridement (SRP) with hand and ultrasonic instruments results in greater clinical improvement than SRP alone. Another objective was to investigate the reduction in the number of microorganisms. METHODS This study was an examiner-blind, randomized and controlled clinical trial using a split-mouth design. Nineteen subjects with moderate-to-severe generalized periodontitis were selected. Immediately following SRP in two randomly chosen contra-lateral quadrants, all pockets 4 mm were additionally treated with the Nd:YAG laser (1064 nm, 6 W, 400 mJ). Clinical assessments (Plaque index, bleeding on pocket probing, probing pocket depth) were performed pre-treatment and at 3 months post-treatment. In each quadrant, one site was sampled for microbiological evaluation at pre-treatment, immediately post-instrumentation and 3 months post-treatment. RESULTS At the 3-month visit, the clinical parameters had significantly improved for both regimens. No significant differences between treatment modalities were observed for any of the clinical parameters at any time. Immediately following instrumentation, the total colony forming units for both groups were significantly reduced as compared with pre-instrumentation. No significant differences between treatment modalities were observed. CONCLUSIONS Three months after SRP, no additional advantage was achieved with the additional use of the Nd:YAG laser. Microbiological findings reflect these clinical results.