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September 18, 2004 at 12:26 pm #3239
1: Oper Dent. 2004 Jul-Aug;29(4):430-6. Related Articles, Links
Influence of the use of Er:YAG laser for cavity preparation and surface treatment in microleakage of resin-modified glass ionomer restorations.
Chinelatti MA, Ramos RP, Chimello DT, Borsatto MC, Pecora JD, Palma-Dibb RG.
Department of Restorative Dentistry, Ribeirao Preto Dental School, University of Sao Paulo, Brazil. firstname.lastname@example.org
This study quantitatively assessed the amount of microleakage on Class V cavities prepared by Er:YAG laser and high-speed handpiece, varying the surface treatment and restoring with a resin-modified glass ionomer cement. Fifty cavities were prepared using either an Er:YAG laser device or a carbide bur at high speed. The surface treatment was performed as follows: Er:YAG laser irradiation (G1); 40% polyacrylic acid (G2); laser + acid (G3); finishing with low speed + laser + acid (G4); conventional bur preparation + acid (G5-control). The samples were restored with Fuji II LC, thermocycled, isolated and immersed in a 50% AgNO3 solution. The restorations were serially sectioned and the extent of dye penetration was measured in milimeters using specific computer software. Data were analyzed by two-way ANOVA and Tukey test. The lowest degree of microleakage was observed for G5, which was statistically similar (p>0.05) to G4 but different (p<0.05) from all the other experiental groups. Lesser microleakage was observed at the occlusal margins than at the cervical margins (p<0.05). It may be concluded that the use of Er:YAG laser for cavity preparation and surface treatment negatively affected the marginal sealing of resin-modified glass ionomer restorations.
PMID: 15279483 [PubMed – indexed for MEDLINE]September 19, 2004 at 3:24 am #9585
Ron any idea what the energy levels they used with the ER laser?
DavidSeptember 19, 2004 at 1:03 pm #9584
Sorry all they have , even on their website, is shown above.September 19, 2004 at 1:16 pm #9586
Makes you question how valid the results are.
DavidSeptember 21, 2004 at 12:26 am #9587
According to the abstract, the G4 group(finishing with low speed + laser + acid) was statistically indifferent from the G5 control group(conventional bur preparation + acid). If the researchers applied a slow speed round bur to the margins of the G4 group after Er:YAG preparation, loose enamel/dentin and products of laser ablation would be removed. This would correlate with the finding of many clinicians that hand instrument planing of margins after erbium laser preparation appears to improve marginal integrity of composite restorations.
Do many folks use Fuji II LC as the entire Class V restoration(except for maybe a patch job on a crown)? I used the old Ketac LC glass ionomer years ago with disastrous results(rapid wear or just fell out). To me it seems that resin modified glass ionomers are best used on dentin at the depths of the restoration and then the exterior of the Class V should be composed of either composite resin or amalgam.