Effectiveness of a 655-nm InGaAsP diode laser to detect subgingival calculus in patients with periodontal disease.

BACKGROUND: Previous in vitro studies have proven laser fluorescence measurement using a 655-nm Indium Gallium Arsenide Phosphide (InGaAsP) based diode laser radiation to be a useful tool to detect subgingival calculus. The aim of this prospective study was to evaluate the 655-nm InGaAsP diode laser in detecting subgingival calculus in patients with periodontal disease compared with photographic assessment during periodontal surgery. METHODS: Twelve patients (six women, six men) aged between 21 and 75 years with periodontitis scheduled for periodontal surgery were included in this prospective study. All laser fluorescence measurements were made before periodontal surgery. Intraoperatively a mucoperiostal flap was performed, subgingival calculus was visualized, and photographic images were taken. The presence of calculus was recorded for each evaluated site. RESULTS: A total of 115 tooth surface sites of 32 teeth from the 12 patients were evaluated before (laser) and during surgery (image). Compared with image evaluation the laser assessment showed a sensitivity of 0.70 (CI(0)(.025) 0.53 to CI(0.975) 0.83) and a specificity of 0.97 (CI(0.025) 0.85 to CI(0.975) 0.99). The overall probability to correctly detect subgingival calculus with the laser (accuracy) was 0.82 (CI(0.025) 0.74 to CI(0.975) 0.88). CONCLUSIONS: The 655-nm diode laser was able to detect subgingival calculus. Hence, the 655 nm diode laser may be used as an additional tool for calculus detection in non-surgical periodontal therapy.