The Er:YAG laser possesses specific characteristics allowing to be used in non-surgical periodontal treatment. The aim of the resent study was to evaluate the long-term clinical effectiveness of Er:YAG laser monotherapy in the treatment of moderate chronic periodontitis and to compare it with conventional hand instrumentation.

MATERIALS AND METHODS: 451 teeth (1,099 periodontal pockets) from 30 patients with moderate chronic periodontitis (initial probing pocket depth 4 to 6 mm) were allocated for subgingival scaling and root planing in two groups - hand instrumentation (control) and Er:YAG laser instrumentation with 100mJ/15Hz (test). Using a computerized periodontal probe, patients were examined for probing pocket depth (PPD), gingival recession (GR), clinical attachment level (CAL), bleeding on probing (BOP), plaque presence (FMPS) at baseline, one, three, six and 12 months after instrumentation.

Inclusion Criteria:

• at least two teeth per quadrant with PPD between 3,6 mm and 6,4 mm;
• loss of clinical attachment up to 4 mm
• bleeding on probing

Exclusion Criteria:

• periodontal treatment in the last 12 months;
• systemic diseases;
• systemic medication