Failure to induce supracrestal bone growth between and around partially inserted titanium implants using bone morphogenetic protein (BMP): an experimental study in dogs

The effect of bone morphogenetic protein on supracrestal bone growth around partially inserted implants in a dog model is described. The lower premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in six dogs. At a surgical exposure 12 weeks later, two 10-mm turned titanium implants were partially inserted, approximately 15 mm apart, in the areas of the P1 and P3 in each side of the mandible, allowing five threads to protrude from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and the space beneath the mesh was filled with bone morphogenetic protein (S300 BMP) in combination with an insoluble bone matrix carrier, or with the carrier alone. The mesh was covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 16 weeks of healing, biopsy specimens were retrieved and examined histologically. Bone was not formed around the protruding implants or in the created space between the implants in any case. The carrier was incompletely resorbed. We conclude that supracrestal bone growth beyond the crestal limit with or without BMP in such a large space as in this experimental design may not be possible.     

Non-surgical treatment of peri-implant mucositis and peri-implantitis: a literature review

Objectives: To review the literature on non-surgical treatment of peri-implant mucositis and peri-implantitis.
Material and Methods: A search of PubMed and The Cochrane Library of the Cochrane Collaboration (CENTRAL) as well as a hand search of articles were conducted. Publications and articles accepted for publication up to November 2007 were included.
Results: Out of 437 studies retrieved a total of 24 studies were selected for the review. Thus the available evidence for non-surgical treatment of peri-implant mucositis and peri-implantitis is scarce.
Conclusions: It was observed that mechanical non-surgical therapy could be effective in the treatment of peri-implant mucositis lesions. Furthermore, the adjunctive use of antimicrobial mouth rinses enhanced the outcome of mechanical therapy of such mucositis lesions. In peri-implantitis lesions non-surgical therapy was not found to be effective. Adjunctive chlorhexidine application had only limited effects on clinical and microbiological parameters. However, adjunctive local or systemic antibiotics were shown to reduce bleeding on probing and probing depths. Minor beneficial effects of laser therapy on peri-implantitis have been shown; this approach needs to be further evaluated. There is a need for randomized-controlled studies evaluating treatment models of non-surgical therapy of peri-implant mucositis and peri-implantitis.     

Periodontal treatment of patients with Papillon-Lefèvre syndrome: a 3-year follow-up

BACKGROUND/AIM: Conventional mechanical periodontal treatment of Papillon-Lefevre syndrome (PLS) has often been reported to fail. This study describes the outcome of a non-surgical periodontal therapy including antimicrobial treatment of nine patients diagnosed with PLS. The patients originate from a total of 15 children and adolescents with PLS for which clinical characteristics are presented. METHODS: Clinical examination including conventional periodontal measurements. Initial treatment including oral hygiene instruction, scaling and root planing and systemic amoxicillin-metronidazole therapy for 6 weeks. After that the patients were enrolled in a 3-month recall maintenance program. In addition to this mechanical supportive maintenance treatment, tetracycline was prescribed and used continuously for 1.5 years. RESULTS/CONCLUSION: On five patients who were showing acceptable standard of oral hygiene and also compliance with the antibiotic medication, development of periodontitis on erupting teeth was prevented and disease activity on the previously periodontally involved teeth controlled during a 3-year period. Poor results of treatment were observed for three patients, all siblings. These patients failed to comply with the medication and also failed to improve their oral hygiene.     

The use of 0.2% chlorhexidine in the absence of a structured mechanical regimen of oral hygiene following the non-surgical treatment of periodontitis

Abstract. The aim of the present study was to evaluate a 0.2% chlorhexidine mouthrinse following the non-surgical treatment of advanced human periodontitis in the absence of a structured mechanical oral hygiene regimen. 10 patients and a total of 1483 sites were used. Recordings for plaque, bleeding, pocket depth and attachment levels were made at baseline and at 3, 6, 9, and 12 months. Debridement was performed under local anaesthesia. No instruction or reinforcement in mechanical ocal hygiene procedures was given at any time. However, at each visit the patients were instructed in the 2× daily use of 0.2% chlorhexidine mouthwash. The plaque indices, scored as % of sites with removable deposits, showed negligible improvement from baseline scores of 80%-100% for all categories of initial probing depth. Mean bleeding score was reduced to 10–20% irrespective of initial probing pocket depth, site location or tooth surface location. Sites ≥7 mm at baseline demonstrated a reduction in mean probing pocket depth of 3.9 mm and a gain in mean probing attachment level of 2.5 mm. Moderately deep sites (4–6.5 mm) demonstrated a reduction in mean probing pocket depth of 2 mm and a gain in mean probing attachment level of 0.8 mm. Shallow sites (≤3.5 mm) demonstrated a reduction in mean probing pocket depth of 0.5 mm and a loss in mean probing attachment level of 0.2 mm. Site-specific attachment level analysis demonstrated that over 80% of losing sites were shallow with low bleeding frequency, indicating that the loss of attachment may have occurred for reasons other than inflammatory periodontal disease. The results indicate that chlorhexidine can be used as an adjunct to inadequate mechanical oral hygiene over an observation period of 1 year.     

Bacterial profile and burden of periodontal infection in subjects with a diagnosis of acute coronary syndrome

BACKGROUND: Periodontitis has been identified as a potential risk factor in cardiovascular diseases. It is possible that the stimulation of host responses to oral infections may result in vascular damage and the inducement of blood clotting. The aim of this study was to assess the role of periodontal infection and bacterial burden as an explanatory variable to the activation of the inflammatory process leading to acute coronary syndrome (ACS). METHODS: A total of 161 consecutive surviving cases admitted with a diagnosis of ACS and 161 control subjects, matched with cases according to their gender, socioeconomic level, and smoking status, were studied. Serum white blood cell (WBC) counts, high- and low-density lipoprotein (HDL/LDL) levels, high-sensitivity C-reactive protein (hsC-rp) levels, and clinical periodontal routine parameters were studied. The subgingival pathogens were assayed by the checkerboard DNA-DNA hybridization method. RESULTS: Total oral bacterial load was higher in the subjects with ACS (mean difference: 17.4x10(5); SD: 10.8; 95% confidence interval [CI]: 4.2 to 17.4; P<0.001), and significant for 26 of 40 species including Porphyromonas gingivalis, Tannerella forsythensis, and Treponema denticola. Serum WBC counts, hsC-rp levels, Streptococcus intermedius, and Streptococcus sanguis, were explanatory factors to acute coronary syndrome status (Nagelkerke r2=0.49). CONCLUSION: The oral bacterial load of S. intermedius, S. sanguis, Streptococcus anginosus, T. forsythensis, T. denticola, and P. gingivalis may be concomitant risk factors in the development of ACS.     

Topical minocycline microspheres versus topical chlorhexidine gel as an adjunct to mechanical debridement of incipient peri-implant infections: a randomized clinical trial

AIM: This randomized clinical trial presents a 12-month follow-up of the clinical and microbiological results after application of minocycline microspheres as an adjunct to mechanical treatment of incipient peri-implant infections compared with an adjunctive treatment using 1% chlorhexidine gel application. MATERIAL AND METHODS: Thirty-two subjects with probing depth > or =4 mm, combined with bleeding and/or exudate on probing and presence of putative pathogenic bacteria were given oral hygiene instructions and mechanical treatment of infected areas adjacent to implants. The subjects were then randomly assigned adjunctive subgingival antimicrobial treatment using either chlorhexidine gel or minocycline microspheres. Sixteen patients in the minocycline group and 14 in the chlorhexidine group completed the study. Follow-up examinations were carried out after 10 days, 1, 2, 3, 6, 9 and 12 months. RESULTS: The adjunctive use of minocycline microspheres resulted in improvements of probing depths and bleeding scores, whereas the adjunctive use of chlorhexidine only resulted in limited reduction of bleeding scores. For the deepest sites of the treated implants in the minocycline group, the mean probing depth was reduced from 5.0 to 4.4 mm at 12 months. This study could not show any significant difference in the levels of bacterial species or groups at any time point between the two antimicrobial agents tested. The present findings encourage further studies on adjunctive use of minocycline microspheres in the treatment of peri-implant lesions. CONCLUSIONS: The use of a local antibiotic as an adjunct to mechanical treatment of incipient peri-implantitis lesions demonstrated improvements in probing depths that were sustained over 12 months.     

Nine- to fourteen-year follow-up of implant treatment. Part II: presence of peri-implant lesions

OBJECTIVES: The aim of this study was to analyse the proportions of peri-implant lesions at implants after 9-14 years of function. MATERIAL AND METHODS: Two hundred and ninety-four patients underwent implant therapy during the years 1988-1992 in Kristianstad County. These individuals were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 218 patients with 999 implants were examined clinically and radiographically. RESULTS: Forty-eight per cent of the implants had probing depth > or =4 mm and bleeding on probing (peri-implant mucositis). In 20.4% of the implants, the bone level was located 3.1 mm apical to the implant shoulder. Progressive bone loss (> or =1.8 mm) during the observation period was found in 7.7% of the implants. Peri-implantitis defined as bone loss > or =1.8 mm compared with 1-year data (the apical border of the bony defect located at or apical to the third thread, i.e. a minimum of 3.1 mm apical to the implant shoulder), combined with bleeding on probing and or pus, were diagnosed among 16% of the patients and 6.6% of the implants. CONCLUSION: After 10 years in use without systematic supportive treatment, peri-implant lesions is a common clinical entity adjacent to titanium implants.