
Research has now established that a thorough understanding of the implant related complications is essential if implant retained restorations are to be employed predictably. Biological complications in implant dentistry are referred to as peri-implant mucositis and peri-implantitis. Peri-implantitis, if not successfully treated, may lead to complete disintegration and implant loss. Bacteria, mainly Gram-negative anaerobes are an essential factor for the onset and progression of peri-implantitis. However, the disease is probably the result of interplay of several factors that may influence the host inflammatory response, including smoking, stress, genetic variation in relevant genes (polymorphism), occlusal overload, impaired healing, poor surgical technique, poor bone quality and poor prosthesis design. Diagnosis is based on changes of colour in the gums, bleeding and probing depth of periimplant pockets, suppuration, x-ray and gradual loss of bone height around the tooth. Therapeutic objectives focus on correcting technical defects by means of surgery and decontamination techniques such as abrasion with carbon particles, citric acid solution, topical tetracycline application and laser surgery.