PubMed · 12083640
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
James McCubbin. 2002. Abfraction.. https://doi.org/10.14219/jada.archive.2002.0250
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A 351-nm laser excitation source was used to perform autofluorescence microscopy of dentin, enamel, and the dentin-enamel junction (DEJ) to obtain information regarding their morphology and spectral characteristics. The emission spectra of these calcified dental tissues were different from one another, and this enabled the DEJ to be imaged and dimensionalized. The DEJ displayed sharp and clearly delineated borders at both its enamel and dentin margins. The dentinal tubules and the enamel prisms appeared to terminate abruptly at the DEJ. The median DEJ width was 10 microm, ranging from 7 to 15 microm, and it did not appear to depend on intratooth position.
BACKGROUND AND OBJECTIVES: We have investigated the fundamental aspects of Nd:YAG laser at the picosecond pulse regime interacting with primary teeth. Because little is present in the literature concerning specific laser ablation for primary teeth with respect to enamel and dentin, this work may open perspectives for new investigations. STUDY DESIGN/MATERIALS AND METHODS: Using a picosecond Nd:YAG laser, different power levels (200, 300, and 350 mW) and different exposition times (5, 10, and 15 seconds) were considered. RESULTS: Micro-morphological aspects of the laser-tooth interaction showed collateral effects in enamel more accentuated than in dentin. Penetration depth in dentin seems to scale up in rate as the time of application progress, for enamel the behavior is the opposite. The overall ablated volume is higher in dentin when compared with enamel, which results in a higher ablated rate as well. CONCLUSIONS: Specific ablation characteristics are observed in either dentin or enamel.
The scientific investigation of fundamental problems plays a decisive role in understanding the mode of action and the consequences of the use of lasers on biological material. One of these fundamental aspects is the investigation of the ablation threshold of various laser wavelengths in dental enamel. Knowledge of the relationships and influencing factors in the laser ablation of hard tooth tissue constitutes the basis for use in patients and the introduction of new indications. The present paper examines the ablation threshold of an Er:YAG laser (lambda=2.94 micro m) and an Er:YSGG laser (lambda=2.79 micro m) in human dental enamel. To this end, 130 enamel samples were taken from wisdom teeth and treated with increasing energy densities of 2-40 J/cm(2). The sample material was mounted and irradiated on an automated linear micropositioner. Treatment was performed with a pulse duration of tau(P(FWHM)) approximately 150 micro s and a pulse repetition rate of 5 Hz for both wavelengths. The repetition rate of the laser and the feed rate of the micropositioner resulted in overlapping of the single pulses. The surface changes were assessed by means of reflected light and scanning electron microscopy. On the basis of the results, it was possible to identify an energy density range as the ablation threshold for both the Er:YAG and the Er:YSGG laser. With the Er:YAG laser, the transition was found in an energy density range of 9-11 J/cm(2). The range for the Er:YSGG laser was slightly higher at 10-14 J/cm(2).