Peri-implantitis is an important disease entity as a result of its high prevalence and the lack of a standard mode of therapy.

Non-surgical therapy of peri-implant disease, especially when bone loss is not high, appears to be partially effective in resolving the disease. In several cases, however, only limited improvements have been reported in the main clinical parameters (bleeding at the survey and presence of the pocket) and there is a clear tendency to relapse of the disease.

In these cases it is therefore recommended to consider adjunctive therapies. Numerous approaches have been used for implant surface decontamination including mechanical, chemical and treatments by means of air-powder or laser.

The aim of the present randomized controlled clinical trial will be to assess the efficacy in improving clinical parameters of two further methods of implant surface decontamination (Er:YAG laser or air-abrasive device) after mechanical cleaning during non surgical treatment of peri-implantitis.

Peri-implantitis, defined as an inflammatory lesion in the surrounding peri-implant tissues with loss of supporting bone, is an important disease entity as a result of its high prevalence and the lack of a standard mode of therapy. Although the current epidemiological data are limited, peri-implantitis affects 28-56% of the subjects and 12-43% of the implants.

Numerous approaches have been used for implant surface decontamination during peri-implant surgery, including mechanical, chemical and laser treatments. Using conventional mechanical means, eradication of pathogens on implant surfaces with threads and often with rough surface structures is difficult. Treatment models, such as debridment, effectively used to treat teeth with periodontitis, cannot be used in the same way on rough threaded implant surfaces. The implant rough surface structure also provides the bacteria with ''protected areas'', inaccessible to conventional mechanical removal.

A treatment protocol that may offer an advantage over traditional mechanical treatment includes the use of laser therapy. Data have shown that treatments with Er:YAG lasers have a bactericidal effect. Er:YAG laser treatment can debride the implant surface effectively and safely. Slightly better clinical results in terms of bleeding on probing and clinical attachment level have been reported by Er:YAG laser treatment as compared with traditional non-surgical mechanical debridement with curette and chlorhexidine.

The air abrasive method for the removal of bacterial plaque on tooth surfaces has also been used in the treatment of peri-implantitis, demonstrating no relevant adverse effects. Until recently, air-polishing devices have used a slurry of water and sodium bicarbonate (NaHCO3) and pressurized air/water. A less abrasive method using an amino acid glycine has been proven to be effective in removing bacterial biofilm structures in deep periodontal pockets and safe by not causing emphysema. Moreover the use of a glycine-based powder does not seem to cause titanium implant surface changes.

The aim of the present randomized controlled clinical trial will be to assess the efficacy in improving clinical parameters of two further methods of implant surface decontamination (Er:YAG laser or air-abrasive device) after mechanical cleaning during non surgical treatment of peri-implantitis.

Inclusion Criteria:

• presence of at least one screw-type titanium implant exhibiting bleeding and/or suppuration on probing combined with:

  1. a PPD ≥ 5 mm and bone loss > 2 mm (compared to crestal bone levels at the time of placement of the reconstruction)
  2. a PPD ≥ 6 mm and bone loss ≥ 3 mm (not compared to crestal bone levels at the time of placement of the reconstruction)

• single tooth and bridgework restorations without overhangings

• no evidence of occlusal overload (i.e. occlusal contacts revealed appropriate adjustment)

• implant function time ≥ 1 year.

Exclusion Criteria:

• Patients with uncontrolled diabetes,
• patients with osteoporosis or under bisphosphonate medication,
• pregnant or lactating women,
• patients with a history of radiotherapy to the head and neck region
• patients with incapability to perform basal oral hygiene measures due to physical or mental disorders
• hollow implants
• implant mobility
• implants at which no position could be identified where proper probing measurements could be performed;
• previous surgical treatment of the peri-implantitis lesions