Peri-implant mucositis 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 mucositis 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 partial resolution and presence of pocket at follow-up visits) 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-implant mucositis.

Peri-implant mucositis, defined as an inflammatory lesion of the surrounding peri-implant tissues without 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-implant mucositis affects 43% of the subjects.

Numerous approaches have been used for implant surface decontamination, 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 debridement, 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 curettes and chlorhexidine.

The air abrasive method for the removal of bacterial plaque on tooth surfaces has also been used in the treatment of mucositis, 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 aminoacid 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 mucositis.

Inclusion Criteria:

• presence of at least one screw-type titanium implant exhibiting bleeding and/or suppuration on probing combined without progressive radiographic bone loss (compared to crestal bone levels at the time of placement of the reconstruction)or <3mm bone level
• 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