Determine the steps in surgical therapy
a) The first step in surgical therapy is to reflect the tissue and degranulate the defect.
b) It is followed by exposing and treating the bacterially contaminated implant surface. The clinician must remove endotoxins from the surface of the failing implant. This is especially true of hydroxyapatite (HA) coated surfaces. The HA coating may be pitted, cracked, and brownish in color and may show areas of resorption down to the base metallic substrate). These surface changes result from the infectious aspects of disease and inflammation. As the pH in the area becomes lower during inflammation, the HA surface begins to decalcify and/or resorb. This resorption process is similar to the effects of periodontal disease, as the implant exhibits the subsequent loss of connective tissue attachment and establishes an osseous defect. It is important in an infected implant with HA surface that is deteriorating that the coating be removed by using an ultrasonic scaler as the use of hand curettes is slow and the air abrasives are associated with the danger of air emboli in marrow spaces.
c) The literature suggests using chemical agents to detoxify the surface of the failing implant. The rationale for their use is the subgingival flora associated with dental implants have been shown to be very similar to those associated with natural teeth. Chemotherapeutic agents such as chlorhexidine gluconate, stannous fluoride, and tetracycline are antimicrobials and/or antibiotics, whichtheoretically would not only kill the periodontopathic bacteria but also would remove endotoxins from a root implant surface. Some of these agents appear to be more effective than others. Studies have concluded that detoxification of the implant surface using citric acid is most beneficial. Prepare a supersaturated solution of citric acid ( pH 1 - crystals mixed in sterile water) and apply with cotton pledget or camel's hair brush for 30 seconds per surface.
d) Once the implant is decontaminated, the next step is to regenerate or obliteratethe osseous defect with a grafting material. Graft with freeze dried bone if completely detoxified or graft with an alloplast if not completely detoxified. The decision to utilize an alloplast or an allograft depends on the effectiveness of the detoxification of the implant surface. If the surface is clean and detoxified,with all exposed areas of the implant visualized and instrumented, it is possible to graft with an allograft material such as DFDBA to achieve biologic healing.However, if the implant surface cannot be cleaned and detoxified (due to vents, holes in the implant fixture, or tortuous osseous defects not accessible to instrumentation), it is advisable to graft with an alloplast material such as HA (particulate form), HTR, or Bioactive Glass. Alloplasts provide a physical, biocompatible "fill," minimize probing depth, support the mucoperiosteal flap, and help prevent further epithelial invagination.
e) In conjunction with the various grafts discussed for bone regeneration around failing implants, clinicians also may use membranes to keep these grafts in the desired location. Resorbable membranes are most commonly used today. Non- resorbable membranes are less commonly used because of the requirement for an additional surgery to recover the intact membrane. It is important that the membrane extends 3-4 mm beyond the surgical defect and secured.
f) The flap should be closed in primary closure with mattress and interrupted sutures without tension.