engleski

Ablative potential of Er:YAG laser in dentin: quantum vs. variable square pulse

Objective: The primary objective was to compare ablated volume and dentin ablation rate of variable squre pulse (VSP), using three different pulse durations, and quantum square pulse (QSP), using two different pulse energy settings and a new digitally controlled dental laser handpiece (X-Runner). The secondary objective was to examine the effects of the ablation with different Er:YAG laser modes on dentin surface using SEM. Background data: The available literature has limited data on the efficiency of different operating modes, pulse durations and the new digitally controlled handpiece of the Er:YAG laser on human dentin. Materials and Methods: Freshly extracted human molars (n=72) were divided into two experimental groups (n=36): 1) Variable Square Pulse (VSP) group and 2) Quantum Square Pulse (QSP) group. Each group was randomly divided in three subgroups (n=12) according to pulse duration, energy or laser handpiece. Cavity preparations were made in dentin at time intervals of 1, 2 and 5 seconds. A laser triangulation profilometer was used to determine cavity volumes and SEM analysis of dentin surface was performed. Results: For time intervals of 1 and 2 s, ablated volume and ablation rate for QSP- 500 mJ were significantly higher in comparison to all groups (p<0.0001). For the 5 s time interval, X- Runner and QSP- 500 mJ were the most efficient in dentin ablation (p<0.0001). Dentin surface was free of smear layer in all groups. Conclusions: The most efficient in dentin ablation were QSP-500 mJ and X-Runner groups. Dentin surface was free of smear layer in all groups.

Er:YAG laser; ablation rate; x-Runner

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