Glycosaminoglycans in peri-implant sulcus fluid from implants placed in sinus-inlay bone grafts

Glycosaminoglycans (GAG) present in peri-implant sulcus fluid (PISF) were u sed as an indicator of the metabolic activity in the supporting tissues of implants placed in maxillary bone or maxillary bone and bone grafts togethe r. The study included 16 patients who received implants (Branemark system(( R))) and sinus-inlay bone grafts. In 12 of these patients, the implants wer e placed in either maxillary bone alone or maxillary bone and sinus-inlay b one grafts in combination. Altogether the patients received a total of 102 implants, of which 73 implants were placed in bone grafts and 29 implants i n maxillary bone alone. Samples of PISF were tested at 2-8 days and at 6 mo nths after abutment connection. Levels of the GAG's chondroitin-4-sulphate (C4S) and hyaluronan (HA) were assessed using cellulose acetate electrophor esis and densitometric scanning of Alcian blue-stained strips against known GAG standards. The C4S was used as a bone metabolic marker, and HA was use d to reflect the progress of soft tissue healing. Comparing grafted and non -grafted regions, there was no significant difference in either C4S levels or HA levels during the first 8 days or at the 6 months period. The levels of HA from the first week collection did not differ significantly from the HA level after 6 months in either type of bone. However, the level of C4S w as significantly lower after 6 months than during the first week, in both m axillary and grafted bone but consistent with a normal metabolic turnover. C4S can therefore be used as an indicator of the progressive healing of bon e adjacent to implants.