Stimulation of proteinase and amidase activities in Porphyromonas (Bacteroides) gingivalis by amino acids and dipeptides.

Proteolytic enzymes from the organism Porphyromonas gingivalis are believed to be involved in the development of periodontitis. Studies on both crude extracts and purified trypsinlike enzymes from this organism indicate that substantial stimulation of both amidase and proteinase activities can be obtained during incubation with glycine-containing compounds. We postulate that P. gingivalis may have developed this unusual property to take advantage of the glycine-rich environment which occurs during the periodontitis-associated degradation of gingival collagen. The finding of such a stimulation in crevicular fluids from discrete periodontal sites has been correlated with the presence of P. gingivalis and could be utilized for the early detection of infection by this organism during the onset of periodontitis.     

Healing after treatment of periodontal intraosseous defects

The present study was performed to determine whether the healing of periodontal intraosseous defects could be improved through the combined use of citric acid conditioning of the root surfaces and grafting of autogenous intraoral cancellous bone. 28 proximal defects in 19 patients were treated surgically including acid conditioning of the root surfaces. Another 25 defects in these patients were treated with acid conditioning combined with osseous grafts using the maxillary tuberosity areas as donor sites. Both therapies, e.g., citric acid conditioning alone and acid conditioning combined with osseous grafting resulted in approximately 1 mm gains of probing attachment and probing bone levels. Within the parameters of this study, osseous grafting did not enhance the effect of citric acid conditioning alone. Limited improvement of the treated defects of the present study was obtained in spite of the use of supplementary regenerative techniques.     

Probiotic supplements and debridement of peri-implant mucositis: A randomized controlled trial

Objective. The aim of this double-blind randomized placebo-controlled trial was to evaluate the effects of probiotic supplements in adjunct to conventional management of peri-implant mucositis. Materials and methods. Forty-nine adult patients with peri-implant mucositis were consecutively recruited after informed consent. After initial mechanical debridement and oral hygiene instructions, the patients received a topical oil application (active or placebo) followed by twice-daily intake of lozenges (active or placebo) for 3 months. The active products contained a mix of two strains of Lactobacillus reuteri. Patients were clinically monitored and sampled at baseline and after 1, 2, 4, 12 and 26 weeks. The clinical end-points were pocket-probing depth (PPD), plaque index (PI) and bleeding on probing (BOP). In addition, the subgingival microbiota was processed with checkerboard DNA-DNA hybridization and samples of gingival crevicular fluid (GCF) were analyzed for selected cytokines with the aid of multiplex immunoassays. Results. After 4 and 12 weeks, all clinical parameters were improved in both the test and the placebo group. PPD and BOP were significantly reduced compared with baseline (p < 0.05), but no significant differences were displayed between the groups. The clinical improvements persisted 3 months after the intervention. No major alterations of the subgingival microflora were disclosed and the levels of inflammatory mediators in GCF did not differ between the groups. Conclusions. Mechanical debridement and oral hygiene reinforcement resulted in clinical improvement of peri-implant mucositis and a reduction in cytokine levels. Probiotic supplements did not provide added benefit to placebo.     

Nine- to fourteen-year follow-up of implant treatment. Part I: implant loss and associations to various factors

Objectives: The aim of the present study was to evaluate the long‐term result of implant therapy, using implant loss as outcome variable. Material and Method: Two hundred and ninty‐four patients had received implant therapy (Brånemark System^®) during the years of 1988–1992 in Kristianstad County, Sweden. The patients were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 9–14 years after implant placements, the patients were again called in for a complete clinical and radiographic examination. Results: Two hundred and eighteen patients treated with 1057 implants were examined. Twenty‐two patients had lost 46 implants and 12 implants were considered “sleeping implants”. The overall survival rate was 95.7%. Implant loss appeared in a cluster in a few patients and early failures were most common. Eight patients lost more than one fixture. A significant relationship was observed between implant loss and periodontal bone loss of the remaining teeth at implant placement. Maxillary, as opposed to mandibulary implants, showed more implant loss if many implants were placed in the jaw. A significant relationship between smoking habits and implant loss was not found. Conclusion: A history of periodontitis seems to be related to implant loss.     

Periodontitis as a potential risk factor for peri-implantitis

Objectives: To review the literature regarding the possible association between a previous history of periodontitis and peri-implantitis.
Material and Methods: A search of MEDLINE as well as a manual search of articles were conducted. Publications and articles accepted for publication up to January 2008 were included.
Results: Out of 951 papers retrieved, a total of three papers were selected for the review. Thus, the available evidence for an association between periodontitis and peri-implantitis is scarce.
Conclusions: Based on three studies with a limited number of patients and considerable variations in study design, different definitions of periodontitis, and confounding variables like smoking that not been accounted for, this systematic review indicates that subjects with a history of periodontitis may be at greater risk for peri-implant infections. It should, however, be stressed that the data to support this conclusion are not very robust.