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. 2016 Feb 13:9692:96920S.
doi: 10.1117/12.2218645. Epub 2016 Feb 29.

Selective removal of dental composite with a diode-pumped Er:YAG laser

William A Fried  1 , Kenneth H Chan  1 , Cynthia L Darling  1 , Daniel Fried  1
Affiliations

Selective removal of dental composite with a diode-pumped Er:YAG laser

William A Fried et al. Proc SPIE Int Soc Opt Eng. .

Abstract

Selective removal of dental composite with high precision is best accomplished using lasers operating at high pulse repetition rates focused to a small spot size. Conventional flash-lamp pumped Er:YAG lasers are poorly suited for this purpose, but new diode-pumped Er:YAG lasers have become available operating at high pulse repetition rates. The purpose of this study was to compare the ablation rates and selectivity of enamel and composite for a 30 W diode-pumped Er:YAG laser operating with a pulse duration of 30-50-μs and evaluate it's suitability for the selective removal of composite from tooth surfaces. The depth of ablation and changes in surface morphology were assessed using digital microscopy. The fluence range of 30-50 J/cm2 appeared optimal for the removal of composite, and damage to sound enamel was limited to less than 100-μm after the removal of composite as thick as 700-800-μm. Future studies will focus on the use of methods of feedback to further increase selectivity.

Keywords: Er:YAG laser; dental composite; selective laser ablation.

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Figures

Fig. 1
Fig. 1
Bovine enamel block 10 × 2 mm with GreenGloo composite applied. For the composite removal studies the laser was scanned across the center of the composite and the incision was expanded to cover the enamel only areas on each side of the composite.
Fig. 2
Fig. 2
Digital microscopy was used to measure the amount of enamel lost and the thickness of composite ablated. The enamel loss was calculated as the mean of the four measurements, T1, T2, L1 & L2. The thickness of the composite removed was measured along CT.
Fig. 3
Fig. 3
3D digital images of incisions produced in enamel and composite at an incident fluence of 35 J/cm2. Depth profile shown at bottom of each image.
Fig. 4
Fig. 4
Relative incision depth for enamel versus composite. The mean±s.d. are shown with 6 measurements per point.
Fig. 5
Fig. 5
3D digital image of the center of the incision at the maximum composite thickness (position CT) at an incident fluence of 29 J/cm2. Depth profile is shown at the bottom.
Fig. 6
Fig. 6
3D digital images showing the varying degree of damage to the adjacent and underlying enamel for two samples at different fluence.
Fig. 7
Fig. 7
Relative incision depth for enamel versus composite. The mean±s.d. are shown with 6 measurements per point.
See this image and copyright information in PMC

References

    1. Gordan VV, Garvan CW, Richman JS, Fellows JL, Rindal DB, Qvist V, Heft MW, Williams OD, Gilbert GH. How dentists diagnose and treat defective restorations: evidence from the dental practice-based research network. Operative Dent. 2009;34(6):664–73. - PMC - PubMed
    1. Bernardo M, Luis H, Martin MD, Leroux BG, Rue T, Leitao J, DeRouen TA. Survival and reasons for failure of amalgam versus composite posterior restorations placed in a randomized clinical trial. JADA. 2007;138(6):775–83. - PubMed
    1. Oliver RG. The effect of different methods of bracket removal on the amount of residual adhesive. Amer J Orthod Dentalfacial Orthop. 1988;93(3):196–200. - PubMed
    1. Hong YH, Lew KK. Quantitative and qualitative assessment of enamel surface following five composite removal methods after bracket debonding. Eur J Orthod. 1995;17(2):121–128. - PubMed
    1. Alexander R, Xie J, Fried D. Selective removal of residual composite from dental enamel surfaces using the third harmonic of a Q-switched Nd:YAG laser. Lasers Surg Med. 2002;30(3):240–5. - PubMed