Peri-implant diseases are common post-restorative complications in implant rehabilitations and they occur with an incidence of 12-43%.

Based on the available data in literature, the surgical therapy for peri-implantitis is effective in disease resolution. Surgical access to peri-implant lesions facilitates the removal of all granulation tissue from the defect area as well as debridement and decontamination of the exposed implant surface defect area.

Different techniques have been used for implant surface decontamination during peri-implant surgery, including mechanical, chemical and laser treatments.

Peri-implantitis are defined as inflammatory diseases caused by bacterial biofilm around implant surface characterized by bleeding on probing, probing depth and eventually bone loss; if not successfully treated they may lead to implant loss. Based on the available parameters that have been reported in literature non surgical therapy doesn't seem to be effective on peri-implantitis. Therefore it is recommended to consider advanced therapies such as surgical interventions when non surgical peri-implant therapy fails to achieve significant improvements in clinical parameters.

Numerous approaches have been used for implant surface decontamination during per-implant surgery, including mechanical, chemical and laser treatments.

Conventional mechanical means don't seem to be effective on peri-implant diseases. In addition, the rough implant surface is a retentive factor for bacterial colonization and therefore makes implant surface difficult to debride.

A treatment protocol that may offer an advantage over traditional mechanical treatment includes the use of laser therapy and air-powder devices. Data have shown that treatments with Er.Yag laser have a bactericidal effect and are safe and effective on implant surfaces. Slightly better clinical results in terms of debridement, probing depth, bleeding on probing and clinical attachment level have been reported by Er:Yag laser treatment compared with traditional non surgical mechanical debridement with titanium curettes and pellet with saline in the surgical treatment of peri-implantitis.

The air abrasive method for debridement has also been used on implant surfaces demonstrating no relevant adverse effect. Until now, powders based on sodium bicarbonate and glycine have been used with pressured air/water. Nowadays a less abrasive method involves the use of erythritol powder.

The aim of the present randomized controlled clinical trial is to assess the efficacy in improving clinical parameters of two further methods of implant decontamination (er:Yag laser or air-abrasive device) after chemical treatment and chemical cleaning during surgical treatment of peri-implantitis in addition to chlorhexidine in vertical defects with keratinised tissue around implant surfaces. Furthermore the bone defect will be filled with bio-material.

Inclusion Criteria:

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

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

• single tooth and bridgework restorations without overhangs

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

• treated chronic periodontitis and proper periodontal maintenance care FMPS < 20%

• non-smoker or light smoking status in smokers (<10 cigarettes per day) 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
• 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