Volume: 2014 | Number: 1
ISSN (print): 1855-9913 | ISSN (web): 1855-9921
Usage of Er:YAG Lasers in Maxillary Sinus Surgeries: A Clinical Comparison of VSP vs Gaussian Profiles
Tosun Tosun, Stefano Benedicenti
The Erbium laser (Er:YAG, 2940 nm wavelength) with its high absorption in water and low penetration depth in soft and hard oral tissues, enables a high ablation depth control in bone surgery. This precise control offers a major advantage, especially in lateral approach sinus-grafting procedures, where often a thin bone wall is present. The pulse-duration control offered by erbium lasers dramatically affects clinical results in terms of ablation capability. Temporal profiles of dental Er:YAG lasers reveal that there are two distinct types of pulse profiles: Square Pulse and Gaussian. The aim of the present retrospective study is to make a clinical comparison of Square Pulse Er:YAG versus Gaussian Er:YAG lasers in maxillary sinus surgeries.
The study consists of two groups: Square Pulse vs Gaussian. In the Square Pulse group, an articulated-arm-based Er:YAG device (LightWalker, Fotona) that produces a Variable Square Pulse (VSP) beam profile was used. The Square Pulse group consists of 7 cases with 10 sinus lifting procedures. The laser power settings used were 400 mJ x 10 Hz = 4 W, 50 μsec pulse duration, 44% air, 33% water spray. In the Gaussian group, a fiber delivery Er:YAG device (VersaWave, Hoya ConBio), which has not been available commercially since June 2011, was used. In the Gaussian group, there were 6 cases with 9 sinus lifting procedures. The power settings of the Gaussian group were 400 mJ x 15 Hz = 6 W, 300 μsec fixed pulse duration, under copious water/air cooling. The surgeon evaluated the clinical usefulness of the instruments by Visual Analog Scale (VAS) according to the parameters of handling, visibility of the surgical field, irrigation, bone cutting speed, working time duration, scoring each on a scale from "poor" 0 (zero) to "perfect" 10. Membrane rupture rate was registered as either absent or present.
The Square Pulse group showed only one membrane rupture and shorter preparation times.
According to the data collected during sinus surgeries, the VSP Er:YAG laser was found to be more effective in comparison with a fixed pulse duration Gaussian profile beam laser.
Key words: dental implant, implant, surgery, sinus lift, sinus lifting, sinus graft, laser, Er:YAG, erbium, variable square pulse, pulse duration, ablation, Gaussian, beam profile.
Article: J. LA&HA, Vol. 2014, No.1; pp.29-32.