Greg, the laser would cleanse also. There are studies that show the laser sterilizes, removes the smear laser,  and etches. There are also studies that indicate increased acid resistance as well.

: J Clin Laser Med Surg 2001 Jun;19(3):159-63 Related Articles, Links  

 
A study on acquired acid resistance of enamel and dentin irradiated by Er,Cr:YSGG laser.

Hossain M, Kimura Y, Nakamura Y, Yamada Y, Kinoshita JI, Matsumoto K.

Department of Endodontics, Showa University School of Dentistry, Tokyo, Japan.

OBJECTIVE: This investigation was performed to evaluate the acid resistance of lased enamel and dentin by Er,Cr:YSGG laser to artificial caries-like lesions by spectrophotometry, and the ultrastructure of lased areas was investigated by scanning electron microscopy (SEM) in vitro. BACKGROUND DATA: In recent years, many studies have been performed to evaluate the effects of Er,Cr:YSGG laser on dental hard tissues. However, there have been only a few studies to determine if this laser is suitable for caries preventive treatments. METHODS: An Er,Cr:YSGG laser was used to irradiate the enamel or dentin samples from 30 extracted human molars at 6 W (67.9 J/cm2) or 5 W (56.6 J/cm2) pulse energy, respectively, with or without water mist. Samples were subjected to 2 microl of 0.1 M lactic acid solution (pH 4.8) for 24 h at 36 degrees C. The parts per million (ppm) of calcium ion (Ca2+) dissolved in each solution was determined by atomic absorption spectrophotometery, and the morphological changes were investigated by SEM. RESULTS: The lowest mean Ca2+ ppm was recorded in the lased samples. SEM observation showed that the lased areas were melted and seemed to be thermally degenerated. After acid demineralization, the thermally degenerated enamel or dentin surfaces were almost unchanged. CONCLUSIONS: The results of this study suggested that Er,Cr:YSGG laser irradiation with and without water mist appears to be effective for increasing acid resistance.

PMID: 11469308 [PubMed – indexed for MEDLINE]

Personally I am not using a matrix to protect adjacent teeth but perhaps I’m missing something with my 2.5 loupes? Glenn?

I direct the laser toward the center of the lesion first then carefully work outward towards DEJ until enamel against adjacent tooth collapses. I didn’t think I was nicking the adjacent tooth but now I’m wondering!!!

Glenn, so no “sparking” against a metal matrix? That’s a fascinating find that the Erbium doesn’t “spark” against a composite matrix because I get real nervous using mine around metal. I blew a trunk fiber trying to do a patch job under an old PFM crown margin but I don’t know the metal content of the crown.

Does anyone know the metal content of composite matrices? If we could determine what metals will damage our lasers or laser tips this would be invaluable. I use sectional matrices from Danville for my composites. Glenn’s observation that laser sparks around amalgam but not on metal matrix is something we really need to investigate and determine the exact mechanism of action.

Al