Characterization of smoker and non smoker human teeth using laser induced breakdown spectroscopy

In this work, the elemental constituents of smoker and nonsmokerteeth samples of human were analyzed by Laser induced breakdownspectroscopy method (LIBS). Many elements have been detected inthe healthy teeth samples, the important once are Ca, P, Mg, Fe, Pband Na. Many differences were found between (female and male)teeth in Ca, P, Mg, Na and Pb contents. The concentrations of mosttoxic elements were found significantly in the smoker group. Themaximum concentrations of toxic elements such as Pb, Cd and Cowere found in older male age above 60 year. Also, it was found thatthe minimum concentrations of trace elements such as Ca, P and Naexist in this age group. From these results it is clear that the LIBStechnique is a powerful tool for fast identification of teeth problems.


Introduction
Light emitting plasmas have been studied earnestly since the 1920s, and laser induced plasmas since 1960 [1].Laser induced breakdown spectroscopy (LIBS) technique based on analyzing of atomic emission spectroscopy for excited atoms and ions of the elements in plasma formed on the surface of the samples by means of focused pulsed laser.There are several new developments of the LIBS method that are reported elsewhere [2].The main benefit of the LIBS technique is that it can be used for direct chemical analysis without difficult chemical preparation provided for the samples.It has a very high sensitivity, reach parts per million [3].This method is used to detect corpse's bones and humans' fossils.It is also used to detect backgrounds characteristic like age, sex, and statues of bodies [4].This method is used in dentistry to detect the caries parts of a tooth, and also in teeth modification.Spectral analysis plasma glow made by pulse laser can be used safely and accurately to monitor the occurrence of cancer [5].

Human teeth
The human tooth consists of four main tissues, enamel is the hardest material found in the human body which protects the other weakly tooth parts from damage, Dentine has a bone like consistency, pulp is found in the tooth center and contains vessels and nerves that keep the tooth alive and the cementum layer covers tooth root [6].The crystalline enamel of a tooth is a biological composite containing 4% water, 95% mineral (carbonated hydroxyapatite), and 1% organic matter [7].These components are not evenly distributed through the tissue.Hydroxyapatite is a mineral with an ideal composition of Ca 10 (PO 4 ) 6 (OH) 2 .The carbonated hydroxyapatite in tooth enamel is crystalline in nature.A large number of trace elements in the range below the parts per billion concentrations are encountered in calcified tissues.The excess or deficiency of trace elements often provides information about diseased states [8].

Smoking effects
Nicotine is the most important constituent among more than 4000 potentially toxic substances in tobacco products.It is the main chemical component responsible for tobacco addiction, appears to mediate the hemodynamic effects of smoking, and has been implicated in the pathogenesis of numerous diseases [9].Studies have also demonstrated the detrimental effects of smoking on oral health.A clinical study [10] observed that smokers had a higher prevalence of moderate and severe periodontitis and higher prevalence and extent of attachment loss and gingival recession than non-smokers, suggesting poorer periodontal health in smokers.In addition, smokers had a higher number of missing teeth than non-smokers.Concerning the bone-implant interface, the deleterious effects of tobacco smoke reflects a series of direct and indirect systemic and local effects on bone metabolism [11].It has been strongly suggested that local exposure of the peri-implant tissues to tobacco products is the main factor leading to an overall increase in implant failure rate in smokers [12].A recent metaanalysis on the subject [13] observed that smoking was associated with a higher risk of dental implant failure.

Some qualitative analysis of plasma parameters
The plasma parameters electron temperature and electron density can be calculated according to Boltzmann equation and Saha-Boltzmann equation respectively [14,15].
where ji is the intensity of the spectral line of the transition from level j to , j is the wavelength, j is the transition probability, j is the statistical weight, j is the energy value of higher level, and exc is the excitation temperature.Thus, a plot of .1:Some of t permanent te

LIBS system
The optica sma ablate faces were erimental sy .) compare more, it is the calc ost higher d to smoker age groups.
the pla for nonsm male and fem in mJ.

Conclusions
LIBS technique can be used for direct chemical analysis for tooth samples without performing a sample preparation.The method has a high sensitivity and its detection for the problems of a tooth sample in a very short time.Distinguishing between nonsmoker and smoker teeth was possible by exploiting the change in the intensity ratios of the spectral lines of the matrix constituent elements Ca and P, and the non-matrix elements in the LIBS spectra of tooth sample.The concentrations of most toxic elements were significantly in the smoker group.The maximum concentrations of toxic elements such as Pb, Cd and Co were found in older male age (above 60 year).
Also, the minimum concentrations of trace elements Ca, P and Na in this aged groups.
Fig. (b) p b. L T plas surf exp Fig. Nd: 10 H wav (300 is fo Fig Figs. 8 and an LIBS si elements in ove 60 year pectively.centrations Pb, Cd and Fig

Fig. 11
Fig. 11: C Finally the luated using electron de ng Saha-Bo Debye quency f p a