Preservation of crestal bone by implant design. A comparative study in minipigs.

OBJECTIVES: To compare crestal bone modeling at three bone level design implants; Astra Tech Osseospeed(™) Implant (AOI), Straumann(®) Bone Level Implant (SBLI) and NobelReplace(™) Tapered Groovy Implant (NBTI). MATERIALS AND METHODS: In 12 minipigs one implant of each design was placed on each side of the mandible with submerged healing. The implant platform was placed at the level of the crest (Group 0), and 1 mm above the crest (Group + 1 mm). In addition, one Straumann(®) Tissue Level Implant STLI was placed as a control on each side of the mandible. At 4 weeks, six animals were sacrificed. In the remaining six animals healing abutments were connected until 12 weeks. Clinical, radiographic, and histologic analyses were made. ANOVA and Mann-Whitney U-tests were used to evaluate differences in bone levels between implant designs. RESULTS: At 4 weeks there was no statistically significant difference in bone changes between implant designs. At 12 weeks implants in Group + 1 mm had minimal bone changes with no differences between implant designs. In Group 0, the AOI and SBLI preserved more crestal bone than NBTI (P < 0.01). Mean distance from the implant platform to the buccal bone was -0.1 ± 0.2 mm for AOI, -0.3 ± 0.3 mm for SBLI, and -1.0 ± 0.3 mm for NBTI. Mean radiographic bone levels from the implant platform were -0.1 ± 0.4 mm for AOI, 0.0 ± 0.3 mm for SBLI and -0.9 ± 0.8 mm for NBTI. CONCLUSION: Greater bone preservation was observed for the AOI and SBLI compared with the NBTI.

Anti-infective surgical therapy of peri-implantitis. A 12-month prospective clinical study.

AIM: The aim of this prospective cohort study was to evaluate an anti-infective surgical protocol for the treatment of peri-implantitis. MATERIALS AND METHODS: Thirty-six implants in 24 partially dentate patients with moderate to advanced peri-implantitis were treated using an anti-infective surgical protocol incorporating open flap debridement and implant surface decontamination, with adjunctive systemic amoxicillin and metronidazole. Treatment outcomes were assessed at 3, 6 and 12 months. Patient-based statistical analyses using multiple regression analyses were performed. RESULTS: There was 100% survival of treated implants at 12 months. At 3 months, there were statistically significant (P < 0.01) reductions in mean probing depths (PD), Bleeding on Probing (BoP) and suppuration. The greater the mean PD at baseline, the greater the PD reduction at 3 months. At 3 months, there was also a significant mean facial mucosal recession of 1 mm (P < 0.001). All these changes were maintained at 6 and 12 months. At 12 months, all treated implants had a mean PD < 5 mm, while 47% of the implants had complete resolution of inflammation (BoP negative). At 12 months, 92% of implants had stable crestal bone levels or bone gain. There were no significant effects of smoking on any of the treatment outcomes. CONCLUSIONS: For the treatment of peri-implantitis, an anti-infective protocol incorporating surgical access, implant surface decontamination and systemic antimicrobials followed by a strict postoperative protocol was effective at 3 months with the results maintained for up to 12 months after treatment.

Systemic antibiotics in periodontal therapy.

Periodontitis is a biofilm infection with a mixed microbial aetiology. Periodontitis is generally treated by non-surgical mechanical debridement and regular periodontal maintenance care. Periodontal surgery may be indicated for some patients to improve access to the root surface for mechanical debridement. A range of systemic antibiotics for treatment of periodontitis has been documented, with some studies showing superior clinical outcomes following adjunctive antibiotics while others do not. This has resulted in controversy as to the role of systemic antibiotics in the treatment of periodontal diseases. Recent systematic reviews have provided an evidence-based assessment of the possible benefits of adjunctive antibiotics in periodontal therapy. This review aims to provide an update on clinical issues of when and how to prescribe systemic antibiotics in periodontal therapy.

Diagnosis and management of peri-implant diseases.

Peri-implant diseases are inflammatory lesions which may affect the peri-implant mucosa only (peri-implant mucositis) or also result in loss of supporting bone (peri-implantitis). Peri-implantitis may lead to loss of the implant. Diagnosis of peri-implant disease requires the use of conventional probing to identify the presence of bleeding on probing, and suppuration, both signs of clinical inflammation. Radiographs are required to detect loss of supporting bone. Baseline probing measurements and radiographs should be obtained once the restoration of the implant is completed to allow longitudinal monitoring of peri-implant conditions. Two cross-sectional reports from Sweden indicate that the prevalence of peri-implant disease is high. Smokers and patients who have a history of periodontitis are more at risk for peri-implant disease. The main goal of treatment of peri-implant disease is to control the infection and to prevent disease progression. A number of studies have documented the successful treatment of peri-implant mucositis combining mechanical debridement and chemical plaque control. There is evidence supporting antimicrobial treatment regimens in combination with non-surgical or surgical debridement for peri-implantitis treatment. Long-term data to support these treatment protocols is limited. Whilst it is possible to treat peri-implantitis, prevention is the goal of supportive therapy.

Disease progression: identification of high-risk groups and individuals for periodontitis.

AIMS: While the role of bacteria in the initiation of periodontitis is primary, a range of host-related factors influence the onset, clinical presentation and rate of progression of disease. The objectives of this review are (1) to present evidence for individual predictive factors associated with a patient's susceptibility to progression of periodontitis and (2) to describe the use of prognostic models aimed at identifying high-risk groups and individuals in a clinical setting. METHODS: Relevant publications in the English language were identified after Medline and PubMed database searches. Because of a paucity of longitudinal studies investigating factors including clinical, demographic, environmental, behavioural, psychosocial, genetic, systemic and microbiologic parameters to identify individuals at risk for disease progression, some association studies were also included in this review. FINDINGS AND CONCLUSIONS: Cigarette smoking is a strong predictor of progressive periodontitis, the effect of which is dose related. High levels of specific bacteria have been predictive of progressive periodontitis in some studies but not all. Diabetics with poor glycaemic control have an increased risk for progression of periodontitis. The evidence for the effect of a number of putative factors including interleukin-1 genotype, osteoporosis and psychosocial factors is inconclusive and requires further investigation in prospective longitudinal studies. Specific and sensitive diagnostic tests for the identification of individuals susceptible to disease progression are not yet a reality. While factors assessed independently may not be valuable in predicting risk of future attachment loss, the combination of factors in a multifactorial model may be useful in identifying individuals at risk for disease progression. A number of multifactorial models for risk assessment, at a subject level have been developed but require validation in prospective longitudinal studies.

Effects of post-surgical cleansing protocols on early plaque control in periodontal and/or periimplant wound healing.

OBJECTIVE: The aim of this RCT was to evaluate early wound healing following specific post-surgical care protocols. MATERIAL AND METHODS: Following periodontal flap surgery, 60 patients were randomly assigned to follow one of two post-surgical protocols. Subjects smoking >20 cigarettes per day were excluded. Patients following the control protocol rinsed twice daily for 1 min with 0.1% of chlorhexidine (CHX) for 4 weeks. In addition to CHX rinsing, patients assigned to the test protocol applied CHX locally using a special very soft surgical toothbrush (Chirugia) from days 3 to 14, and a soft toothbrush (Ultrasuave) from days 14 to 28, twice daily. Baseline measurements included gingival crevicular fluid (GCF) flow rate, probing depth, probing attachment level, presence of bleeding on probing and full-mouth plaque score. Measurements were repeated at 1, 2 and 4 weeks after surgery. RESULTS: Both post-surgical protocols resulted in successful wound healing and optimal wound closure at 4 weeks. There were no statistical differences in the GCF flow rate between test and control protocols. There was a lower incidence of recession of > or =2 mm following the test protocol. CONCLUSION: The use of specific post-surgical cleansing protocols including the introduction of mechanical cleansing at day 3, using local application of CHX in addition to daily rinsing with CHX may be recommended.

A systematic review of the effect of surgical debridement vs non-surgical debridement for the treatment of chronic periodontitis.

OBJECTIVE: To systematically review the evidence of effectiveness of surgical vs. non-surgical therapy for the treatment of chronic periodontal disease. METHODS: A search was conducted for randomized controlled trials of at least 12 months duration comparing surgical with non-surgical treatment of chronic periodontal disease. Data sources included the National Library of Medicine computerised bibliographic database MEDLINE, and the Cochrane Oral Health Group (COHG) Specialist Trials Register. Screening, data abstraction and quality assessment were conducted independently by multiple reviewers (L.H., F.H., L.T.). The primary outcome measures evaluated were gain in clinical attachment level (CAL) and reduction in probing pocket depth (PPD). RESULTS: The search provided 589 abstracts of which six randomized controlled trials were included. Meta-analysis evaluation of these studies indicated that 12 months following treatment, surgical therapy resulted in 0.6 mm more PPD reduction (WMD 0.58 mm; 95% CI 0.38, 0.79) and 0.2 mm more CAL gain (WMD 0.19 mm; 95% CI 0.04, 0.35) than non-surgical therapy in deep pockets (>6 mm). In 4-6 mm pockets scaling and root planing resulted in 0.4 mm more attachment gain (WMD -0.37 mm; 95% CI -0.49, -0.26) and 0.4 mm less probing depth reduction (WMD 0.35 mm; 95% CI 0.23, 0.47) than surgical therapy. In shallow pockets (1-3 mm) non-surgical therapy resulted in 0.5 mm less attachment loss (WMD -0.51 mm; 95% CI -0.74, -0.29) than surgical therapy. CONCLUSIONS: Both scaling and root planing alone and scaling and root planing combined with flap procedure are effective methods for the treatment of chronic periodontitis in terms of attachment level gain and reduction in gingival inflammation. In the treatment of deep pockets open flap debridement results in greater PPD reduction and clinical attachment gain.