IADR Abstract Archives
Investigating the Effect of 9.3-µm CO2 Laser on Dentin Tubules Occlusion in Human Molars
Objectives: The aim of this study was to evaluate the effect of 9.3-µm CO2 laser parameters on extracted human dentin for safely occluding dentinal tubules.
Methods: Dentin slabs of extracted human molars were obtained by cutting molar teeth perpendicular to the long axis, and the dentinal tubules were exposed by placing dentin slabs in EDTA for 30s. A 9.3-μm CO2 laser (Solea, Convergent Dental, Waltham, MA) was used to irradiate the surfaces of dentin and dentinal tubules in the fluence range of 0 – 3.5 J/cm2. Laser pulse fluence was changed by adjusting the combination of laser spot size (0.3 – 1 mm diameter) and pulse energy (0 – 6.5 mJ). Pulse repetition rate was varied in the ranges of low (15 Hz), medium (300-350 Hz) and high (870 Hz). No water or air irrigation was used. Scanning Electron Microscopy (SEM) and light microscopy of dentin were captured and used for imaging the effect of laser on the dentinal tubules and the intertubular dentin.
Results: Peritubular dentin melting and occluding the dentinal tubules was observed for pulse fluences above 0.2 J/cm2. The SEM and light microscopy images show charring appearing in the form of frost and carbonization. At low and medium frequencies and fluences, the charring and melting of organic material can be removed using microbrushing as illustrated in Fig 1. High fluences and high frequency produced plume, permanent charring and ablation of dentin.
Conclusions: 9.3-μm CO2 laser can safely and efficiently occlude open human dentinal tubules with no charring for low frequencies and fluences.
Methods: Dentin slabs of extracted human molars were obtained by cutting molar teeth perpendicular to the long axis, and the dentinal tubules were exposed by placing dentin slabs in EDTA for 30s. A 9.3-μm CO2 laser (Solea, Convergent Dental, Waltham, MA) was used to irradiate the surfaces of dentin and dentinal tubules in the fluence range of 0 – 3.5 J/cm2. Laser pulse fluence was changed by adjusting the combination of laser spot size (0.3 – 1 mm diameter) and pulse energy (0 – 6.5 mJ). Pulse repetition rate was varied in the ranges of low (15 Hz), medium (300-350 Hz) and high (870 Hz). No water or air irrigation was used. Scanning Electron Microscopy (SEM) and light microscopy of dentin were captured and used for imaging the effect of laser on the dentinal tubules and the intertubular dentin.
Results: Peritubular dentin melting and occluding the dentinal tubules was observed for pulse fluences above 0.2 J/cm2. The SEM and light microscopy images show charring appearing in the form of frost and carbonization. At low and medium frequencies and fluences, the charring and melting of organic material can be removed using microbrushing as illustrated in Fig 1. High fluences and high frequency produced plume, permanent charring and ablation of dentin.
Conclusions: 9.3-μm CO2 laser can safely and efficiently occlude open human dentinal tubules with no charring for low frequencies and fluences.
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