Periodontal treatment with an Er:YAG laser or scaling and root planing.: A 2-year follow-up split-mouth study

Background: Non-surgical periodontal treatment with an Er:YAG laser has been shown to result in significant clinical attachment level gain; however, clinical results have not been established on a long-term basis following Er:YAG laser treatment. Therefore, the aim of the present study was to present the 2-year results following non-surgical periodontal treatment with an Er:YAG laser or scaling and root planing. Methods: Twenty patients with moderate to advanced periodontal destruction were treated under local anesthesia, and the quadrants were randomly allocated in a split-mouth design to either 1) Er:YAG laser (ERL) using an energy level of 160 mJ/pulse and 10 Hz, or 2) scaling and root planing (SRP) using hand instruments. The following clinical parameters were evaluated at baseline and at 1 and 2 years after treatment: plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and clinical attachment level (CAL). Subgingival plaque samples were taken at each appointment and analyzed using dark-field microscopy for the presence of cocci, non-motile rods, motile rods, and spirochetes. The primary outcome variable was CAL. No statistically significant differences between the groups were found at baseline. Power analysis to determine superiority of ERL treatment showed that the available sample size would yield 99% power to detect a 1 mm difference. Results: The sites treated with ERL demonstrated mean CAL change from 6.3 +/- 1.1 mm to 4.5 +/- 0.4 mm (P <0.001) and to 4.9 +/- 0.4 mm (P <0.001) at 1 and 2 years, respectively. No statistically significant differences were found between the CAL mean at I and 2 years postoperatively. The sites treated with SRP showed a mean CAL change from 6.5 +/- 1.0 mm to 5.6 +/- 0.4 mm (P <0.001) and to 5.8 +/- 0.4 mm (P <0.001) at 1 and 2 years, respectively. The CAL change between 1 and 2 years did not present statistically significant differences. Both groups showed a significant increase of cocci and non-motile rods and a decrease in the amount of spirochetes. However, at the 1- and 2-year examination, the statistical analysis showed a significant difference for the CAL (P <0.001, respectively) between the 2 treatment groups. Conclusion: It was concluded that the CAL gain obtained following nonsurgical periodontal treatment with ERL or SRP can be maintained over a 2-year period.