The aim of this controlled, parallel design clinical study was to evaluate the effectiveness of an Er:YAG (erbium-doped:yttrium, aluminum, and garnet) laser for nonsurgical treatment of periimplantitis lesions. Twenty patients, each of whom displayed at least one implant with (a) moderate and (b) advanced periimplantitis (n=40 implants; IMZ, ITI, Spline Twist, ZL-Duraplant, Camlog), were randomly instrumented nonsurgically using either (1) an Er:YAG laser (100 mJ/pulse, 10 Hz) device (LAS) or (2) mechanical debridement using plastic curettes and antiseptic therapy with chlorhexidine digluconate (0.2%) (C). The following clinical parameters were measured at baseline, 3, 6, and 12 months after treatment: plaque index, bleeding on probing (BOP), probing depth, gingival recession, and clinical attachment level (CAL). Mean BOP improved significantly in both groups at 3, 6, and 12 months (a- lesions: P<0.001 and b- lesions: P<0.01, respectively). After 3 and 6 months, the mean reduction of BOP was significantly higher in the LAS group when compared to the C group (a- and b- lesions: P<0.01 and P<0.05, respectively). At 3 and 6 months, both groups revealed significant CAL gains at a- and b- lesions (P<0.01, respectively). In both groups, however, the mean CAL at a- and b- lesions was not significantly different from the respective baseline values at 12 months (P>0.05, respectively). Although treatment of periimplantitis lesions with LAS resulted in a significantly higher BOP reduction than C, its effectiveness seemed to be limited to a period of 6 months, particularly at b- lesions.
