Abrasives in snuff?

Oral Health Effects of Combusted and Smokeless Tobacco Products

The oral cavity is usually the first part of a consumer's body exposed to the constituents of tobacco products or their emissions. Consequently, the oral cavity is a frequent site for carcinogenic, microbial, immunologic, and clinical effects of tobacco use. This article summarizes 5 presentations on various aspects of oral health affected by combusted or noncombusted tobacco products from a recent conference, "Oral Health Effects of Tobacco Products: Science and Regulatory Policy," sponsored by the American Association for Dental Research and the Food and Drug Administration.

Abrasion: A Common Dental Problem Revisited

Dental abrasion is most commonly seen at the cervical necks of teeth, but can occur in any area, even inter-dentally from vigorous and incorrect use of dental floss. Acid erosion has been implicated in the initiation and progress of the cervical lesion, while tooth-brush abrasion has long been held as the prime cause of cervical abrasion. Identification of the risk factors is clearly important in order to modify any habits and provide appropriate advice.

Role of plasma membrane disruption in reference moist smokeless tobacco-induced cell death

An oral injury is thought to presage the development of mucosal lesions that are common in moist smokeless tobacco (MST) users. The abrasion or mechanical stress caused by direct contact of MST with the oral mucosa may contribute to this injury by causing transient disruptions in the cell membrane. In order to test this hypothesis, we developed an in vitro exposure system that directly exposes cells to reference MST on a rocking platform to simulate the abrasion that might be experienced in the oral cavity when using MST. Using this treatment paradigm, we monitored plasma membrane disruption as a measure of cell wounding caused by direct interaction of the tobacco material itself with monolayer cultures of Het-1A immortalized human esophageal cells as a potential contributor to the injury process. We found that a washed reference MST preparation, in which MST-associated chemicals were removed but the tobacco material retained, causes cell wounding as indicated by the uptake through plasma membrane disruptions of a fluorescent marker normally impermeable to the cell. Having established that non-chemical properties of MST cause cell wounding, subsequent experiments revealed that cell wounding during simultaneous exposure to an aqueous MST-extract result in greater than additive cell death when compared to treatment with washed MST or MST-extract alone. Furthermore, we found that the high levels of free calcium found in MST-extract appear to be playing an important role. Taken together, these results indicate that MST-induced oral injury may result from a combined interaction of physical disruption of the plasma membrane by the tobacco material itself and the adverse effects of MST chemical constituents, notably high levels of calcium, that gain entry to the cell by way of MST-induced cell wounding.

Epidemiologic perspectives on smokeless tobacco marketing and population harm

Moist snuff is the most popular form of orally-used smokeless tobacco in North America and parts of Europe. Because moist snuff use conveys lower risks for morbidity or mortality than does cigarette smoking, its use has been proposed as a tobacco harm-reduction strategy. This article critically reviews new and published epidemiologic evidence on health effects of moist snuff and its patterns of use relative to smoking in the United States, Sweden, and Norway. The available evidence suggests that: (1) moist snuff is a human carcinogen and toxin, (2) increased promotion of moist snuff has led to increased sales in those countries, (3) the uptake of moist snuff in these three countries during the past several decades has occurred primarily among adolescent and young adult men, (4) increased prevalence of snuff use has not been associated consistently with a reduction in smoking initiation or prevalence, (5) moist snuff use apparently plays a very minor role in smoking cessation in the U.S. and an inconsistent role in Sweden, (6) U.S. states with the lowest smoking prevalence also tend to have the lowest prevalence of snuff use, (7) there are no data on the efficacy of snuff as a smoking-cessation method, (8) the prevalence of cigarette smoking is relatively high among people who use snuff, and (9) snuff use is more consistently associated with partial substitution for smoking than with complete substitution. The evidence base for promotion of snuff use as a public health strategy is weak and inconsistent.

An individual tooth wear index and an analysis of factors correlated to incisal and occlusal wear in an adult Swedish population

The aim of the study was to introduce an individual tooth wear index and to use this index to investigate factors correlated to occlusal wear. The material consisted of 585 randomly selected dentate individuals from the community of Jönköping, Sweden, who in 1983 reached the age of 20, 30, 40, 50, 60, 70, or 80 years. The degree of incisal and occlusal wear was evaluated for each single tooth in accordance with criteria presented earlier. An individual tooth wear index, which made it possible to rank individuals in accordance with incisal and occlusal wear, was used as dependent variable to investigate factors related to incisal and occlusal wear. Of all factors analyzed, the following were found to correlate significantly with increased incisal and occlusal wear: number of existing teeth, age, sex, occurrence of bruxism, use of snuff, and saliva buffer capacity. Stepwise multiple regression analysis gave a total explanation factor of R2 = 0.41. It was also possible to distinguish well between groups of individuals with and without tooth wear by means of these factors.