Here is the interesting article I found in March 2004 online on Nd Yag and Desensitization of exposed dentinal tubules.

The article was in Journal of Endodontics which is free until May 2004 so check it out and download it.

Here is the abstract with positive findings and the link to the article online.

link for the PDF is here………..

http://www.jendodon.com/pt/re/jendodontics/pdfhandler.00004770-200403000-00001.pdf;jsessionid=ACUdUWi38ocx29z7xe7aT1iXYtCb1rUJ36gGgSwDKcKAqtC2FpjR!370758841

Glenn

Abstract
Our previous in vitro study indicated that Nd:YAG laser irradiation on dentin could melt normal dentin surface and close the exposed dentinal tubule orifices without creating surface cracks. This study evaluated the morphologic changes of hypersensitive dentin after Nd:YAG laser irradiation. Thirty patients with clinically diagnosed cervical dentin hypersensitive teeth were treated with a Nd:YAG laser of 30 mJ intensity at 10 pulses per second for 2 min. An impression of the sensitive area was taken before and after laser treatment and then examined with a scanning electron microscope. The impression of the dentin surface after Nd:YAG laser treatment showed no protrusive rods, in contrast with the presence of numerous rods before laser irradiation. Because protrusive rods are a measure of open dentinal tubules, we interpret these data to support the hypothesis that Nd:YAG laser irradiation at specifications of 30 mJ, 10 pulses per second, and 2 min can be used to seal the exposed dentinal tubules.

Dentinal hypersensitivity has long been a common clinical problem in dental practices. It is characterized by brief, sharp pain that occurs in response to stimuli such as thermal changes or chemical (osmotic) and tactile stimuli. The highest prevalence of dentinal hypersensitivity occurrence has been in the 20- to 40-yr age group, with reported percentages of 33.3% to 34.9% (1). Cold stimulus is thought to cause the greatest discomfort, and the predominantly affected teeth are premolars (30.6%) and incisors (28%).

Exposure of dentin is closely related to dentinal hypersensitivity. This symptom was considered to be caused partly by the presence of open dentinal tubules at the exposed dentin surface, where the tubules were wider and more numerous than in nonsensitive areas (2, 3). Several factors can contribute to the exposure of dentin, such as toothbrush abrasion, gingival recession, periodontal treatment, acidic diet, cuspal grinding (4), and abfractive lesions (5).

The exact mechanism of dentinal hypersensitivity, however, is still controversial. Hydrodynamic theory, the most accepted hypothesis, states that the stimulus causing convective fluid flow in dentinal tubules is related to the permeability of dentin (6). This fluid flow transmits a variety of physical stimuli into electrical nerve activity. The low-threshold Ad fiber then mediates the sharp, transient pain that is typical of dentinal hypersensitivity.

Grossman (7) suggested many prerequisites for the treatment of dentinal hypersensitivity in 1935, and these conditions are still regarded as basic principles to abide by when considering treatment. These requirements include that treatment be nonirritant to the pulp, relatively painless on application, easily performed, rapid in action, effective for a long period, and consistently effective, without staining effects. According to these requirements, two mainstream treatment methods have been extensively studied. One method is to block the exposed dentinal tubules, and the other is to reduce the excitability of sensory nerves. Some dentinal hypersensitivity treatment agents have thus been developed, including protein precipitants, tubule obtundents, nerve inactivators, and physical agents.

In addition to these methods, lasers are playing a prominent role in treating dentinal hypersensitivity and include the He-Ne laser, GaAlAs laser, Nd:YAG laser, CO2 laser (8), and Er:YAG laser (9). Our previous study demonstrated that a dentin surface irradiated with Nd:YAG laser was sufficiently melted to achieve closure of exposed dentinal orifices without producing dentin surface cracks (10). Further study showed that the sealing depth was approximately 4 ìm into the dentinal tubules (11). Until now, however, the clinically therapeutic effects regarding the surface changes of dentinal hypersensitivity before and after Nd:YAG laser treatment have not been reported. The purpose of this study was to evaluate the morphologic changes of a dentin hypersensitivity area before and after Nd:YAG laser irradiation.