These data support the hypothesis of differences between populations in the prevalence of periodontopathic bacteria and of greater attachment loss in sites infected with highly leucotoxic A. actinomycetemcomitans. Detection of highly leucotoxic A. actinomycetemcomitans in children and adolescents may be a useful marker for aggressive periodontitis.

Different periodontitis definitions have been used in periodontal research. This study assessed the impact of case definition on the prevalence and extent rates of periodontitis. A data set including 340 periodontal records, collected in Belo Horizonte, Brazil, was used. Periodontitis was defined as: 1) one site with probing depth (PD) >or= 4 mm; 2) clinical attachment level (CAL) >or= 5 mm in >or= 4 sites + one site with PD >or= 4 mm; 3) CAL >or= 6 mm in >or= 2 teeth + one site with PD >or= 5 mm; 4) >or= 4 teeth with >or= 1 sites with PD >or= 4 mm + CAL >or= 3 mm; 5a) interproximal CAL or PD >or= 4 mm at >or= 2 sites, not on the same tooth; and 5b) interproximal CAL of >or= 6 mm at >or= 2 sites, not on the same tooth + PD >or= 5 mm at >or= 1 proximal site. Definition 5 was determined to be the gold standard and the definitions were compared by means of agreement, sensitivity, specificity, and positive and negative predictive values. Prevalence and extent rates greatly varied, from 13.8% to 65.3% and from 9.7% to 55.6%, respectively. The use of different case definitions has a great impact on the prevalence and extent rates of periodontitis.

Bacterial frequency increased from peri-implant/periodontal health to peri-implantitis/periodontitis but not from mucositis/gingivitis to peri-implantitis/periodontitis. There was a trend towards higher bacterial frequency in teeth than implants.

The aim of this study was to evaluate the prevalence of peri-implant diseases around Branemark system implants in Brazilians and the possible relationship with periodontal bone loss, systemic condition, and demographic profile. A total of 113 individuals were enrolled in this study, and they received 347 implants. The implants were clinically and radiographically examined and diagnosed as healthy implants, mucositis, or peri-implantitis. The demographic and systemic profiles of the individuals were assessed via questionnaires, and the time of loading was obtained from files. The presence of periodontal bone loss in partially edentulous patients was determined by standardized radiographic evaluation. With regard to implants, the prevalence was 60.5% (n = 210), 32% (n = 111), and 7.5% (n = 26) for healthy tissues, mucositis, and peri-implantitis, respectively. No correlation was found between peri-implant tissue conditions and socioeconomic status, body mass index, smoking status, gender, age, diabetes mellitus, osteopenia, and osteoporosis. Statistically significant positive correlations were found in implants with mucositis and peri-implantitis in relation to time of loading and with peri-implantitis in relation to periodontal bone loss in the 4 quadrants (P < .05). Presence of peri-implant diseases may be associated with the increasing time of loading and generalized periodontal bone loss.

The risk profile influenced the recurrence of periodontitis and tooth loss. RCs had less recurrence of periodontitis and less tooth loss. The PRA model can be useful in particularizing the risk of patients and adjusting recall intervals.

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

PGC individuals, especially smokers, presented with a higher progression of periodontitis and tooth loss compared to NDC and GGC individuals. This result highlights the influence of glycemic control in maintaining a good periodontal status.

The adjuvant use of AZ did not provide any significant benefit, independently of the treatment protocol. The adjuvant use of CHX showed a more expressive and significant improvement in clinical and microbiologic parameters, especially in the FMD protocol, followed by QS.