Laser Treatment of Chronic Periodontitis
The use of lasers in periodontal practice has become a desirable alternative to traditional scalpel surgery; however, a deficiency in published evidence supporting the efficacy of such treatment exists. A recent review by Cobb, Low, and Coluzzi (2010) presents the current peer-reviewed evidence on the use of the most commonly used dental lasers over the last decade and explores why the use of such lasers in periodontal therapy remains controversial. The results of this review are summarized below.
Cobb, C., Low, S., Coluzzi, D. (2010). Lasers and the Treatment of Chronic Periodontitis. Dent Clin N AM 54 (35-53).
Nd:YAG Laser (1064 nm) â€“ well-designed and adequately powered studies are severely limited with insufficient evidence to support evidence-based decision making when using this laser. Specifically, the derivation of evidence-based conclusions from the published literature is speculative due to weak and confusing evidence. When laser therapies are compared with conventional open-flap procedures, the conclusions consistently reveal no statistical or clinical significant differences between traditional surgery and laser-mediated periodontal surgery. Although proponents of Nd:YAG have promoted the laser as being effective against pigmented bacteria (i.e., Porphyromonas spp, Prevotella spp), common periodontal diseases exhibit a diverse population of non-pigment producing bacteria.
ER:YAG and ER,CR:YSGG Lasers (2940 nm and 2780 nm, respectively) â€“ erbium lasers are effective in removing calculus and reducing PPD. Several studies have demonstrated safe and effective root substance removal without negative thermal effects. A collective average of 11 clinical trials shows equivalent or slightly greater reductions in PPD (2.29 mm vs 1.93 mm), gains in CAL (1.73 vs 1.26 mm), and decreased BOP (47% vs 43%) when compared to control treatments. Interestingly, of the four studies reporting effects of treatment on subgingival microbial levels, none showed a significant difference between treatment groups.
Diode Laser (809-980 nm) â€“ the purported benefits are based on the premise that subgingival curretage is an effective treatment and significant reduction in subgingival microbial populations are predictably achieved. In the five published clinical trials, none measured all four of the usual clinical parameters (reductions in PPD, BOP, subgingival microbes, or gains in CAL), therefore a meta analysis could not be performed by Cobb et al. Specific trends showed greater reductions in PPD and BOP in laser groups with a nearly equivalent gain in CAL. Two studies reported no significant difference between treatment groups. Despite the equivalency between laser-treated sites vs controls, uncontrolled case studies report successful periodontal therapy when using diode and Nd:YAG lasers as adjuncts to SRP. Although diode lasers are effective for soft-tissue applications, offering excellent incision, hemostasis, and coagulation, when combined with the appropriate choice of parameters can result in soft tissue penetration ranging from 0.5 mm to 3 mm.
CO2 Laser (10,600 nm) â€“ carbon dioxide lasers are effective in removing soft tissue and inflamed pockets while achieving good hemostasis. Only two published clinical trials show the effect on PD and the investigators reported no significant differences between treatment groups for reduced PPD and reduction in BOP. CAL gains were statistically significant in favor of only one of the CO2 treatment groups. The primary caution when using CO2 laser relates to the high absorption by hydroxyapatite and water. Therefore, clinicians are well-advised to carefully direct energy beam and use low energy densities to avoid damage to healthy hard tissues.
Photodynamic Therapy (PDT, 635 nm to 690 nm) â€“ uses a combination of visible light and a photosensitizer; however, as with the diode laser, there are a small number of published clinical trials and the collective differences for measurable clinical parameters are not particularly noteworthy. The main premise for using PDT is to reduce subgingival microbes; however, only one of the five published trials measured this parameter and reported no significant difference between PDT and SRP treatments.