Influence of the Total Antioxidant Content of Saliva on Dental Caries

Introduction

Dental caries is one of the most common, but rarely life threatening disease¹. It is characterized by a localized, transmissible, pathological infectious processes that ends up in the destruction of hard dental tissue². Among the factors that have been related to grater cariogenic activity are inadequate dental hygiene and care, the existence of active caries or a family history of caries, a high concentration in the mouth of bacteria with acidophilic activity (Streptococcus mutans or lactobacillus), reduced salivary flow a cariogenic diet or inadequate levels of fluoride in drinking water³.

Streptococcus mutans is considered to be the main cause of dental caries. A study stated that Mutans Streptococci participate in the formation of biofilms on tooth surfaces⁴. Antioxidants constitute an important part of our diet and these, together with extra cellular antioxidants and those of the enzymatic systems, can prevent various inflammatory, infectious or tumoural processes⁵. Various authors^5,6 have examined the relationship between the composition of the saliva and cariogenic activity. A study showed that the amount of caries in deciduous teeth is in direct proportion to the observed total antioxidant capacity of saliva⁷.

Cigarette or tobacco smoke is involved in the pathogenesis of several diseases including local toxic effects in the oral cavity. The noxious effects of smoke compounds justify the high incidents of periodontal diseases, caries and neoplastic diseases of oral tissues in smokers⁸. Exposure to oxidant chemicals in smoke is associated with depletion of endogenous levels of antioxidants in the systemic compartment. Studies have reported that smoking results in low antioxidant concentrations in plasma⁹.

The aim of the present study is to evaluate the status of Total Antioxidant Capacity (TAC) in caries patients with and without smoking habit.

Materials and Methods

The present study was done at A. B. Shetty Memorial Institute of Dental Sciences after getting the institutional ethical clearance. The study was comprised of 80 participants, belonging to age group 30-40 years, in four groups. A written informed consent was obtained prior to enrollment of participants.

• Group I: 20 Smoking individuals with caries.

• Group II: 20 Smoking individuals without caries.

• Group III: 20 Healthy individuals without any caries or smoking habits.

• Group IV: 20 Non-smoking individuals with caries.

Collection and isolation of Streptococcus mutans

Unstimulated saliva was collected in sterile sample collection bottles from patients with caries and without caries with and without smoking habit¹⁰. Saliva samples were vortexed and serially dilutedto 10folds in 0.05M phosphate buffer. 100μl of the aliquotes were cultured onto Mutans Sanguis Agar (Himedia, Bombay) plates. The plates were incubated at 37°C for 24-48 hrs. Colonies were identified as Streptococcus mutans by doing grams staining and biochemical tests like Inulin and Mannitol fermentation, Esculin hydrolysis in the presence and absence of bile, Urease and resistance to Bacitracin. The St. mutans ferments both Inulin and Mannitol. Esculin hydrolysis is negative in presence of bile and positive in absence of bile. Urease is negative and it is resistance to 2U of Bacitracin.

Estimation of total antioxidant capacity (TAC)

Total antioxidant capacity was estimated by phosphomolybdenum method¹¹. This quantitative assay is based on the conversion of Molybdenum (Mo VI) by reducing agents like antioxidants to Molybdenum (Mo V), which further reacts with phosphate under acidic pH resulting in the formation of a green coloured complex. The intensity of which can be read spectrophotometrically at 695 nm.

Results

The data of TAC was analyzed by one way Annova using Prism software. Table 1 is representing the level of TAC as mean ± standard deviation in all four groups. The data shows significant decrease in the TAC of smokers with caries than non-smokers with caries (P <0.0001) and it is also significant over smokers without caries (P = 0.0005). Nonsmokers with caries showed higher level of TAC (162.0 ± 6.339 μg/ml) than healthy individuals without any smoking habit (136.5 ± 17.08 μg/ml )(Table 2 and Fig 1)

Close

Fig 1

Graph showing Total Antioxidant Capacity in Smokers and Nonsmokers with and without caries.

Export to PPT

Discussion

Dental Caries is a bacterial plaque-dependent disease of the dentition that is characterized by a progressive, intermittent demineralization of enamel, dentin and cement with a characteristic pattern of decay that may lead to total destruction of coronal dental tissues and the formation of pulpal abuses, Oral microorganisms, when organized in voluminous masses as dental plaque on tooth surfaces, hydrolyte starches and metabolize sugars to form acids (mainly lactic acid) that demineralize the hard tissue underneath¹².

When antioxidant defenses are weakened, body cells and tissues become more prone to develop dysfunction and /or disease. Total antioxidant capacity evaluation is the first step in the search of diseases in biochemistry, medicine, food and nutritional sciences¹³.

Saliva is considered as mirror of the body is readily available and collection process is fairly straight forward¹⁴. Saliva being the diagnostic tool for detection of dental caries shows lower flow rate, viscosity, pH and buffering capacity¹⁵. In this study unstimulated saliva was collected for the assessment of Streptococcus mutans and total antioxidant level.

In the present study smokers with and without caries (group 1 and 2 ) shows decrease in Total Antioxidant level compared to the nonsmokers with and without caries (group 3 and 4). This may be due to the presence of high amounts of free radicals in cigaratte smoke that generate an oxidative stress in the smokers body that may cause exhaustion of antioxidants of the body¹⁶.

In our study we found significant increase (P=0.0142) of Total Antioxidant level in nonsmokers with caries (group 4) than healthy individuals (group3) without any habit of smoking. Similar studies done on children reveals the same results^17,18,19. The increase may due to an increase in the suspension of proteins and of cariogenic activity⁶ and it has been suggested that the levels of antioxidants could be altered in response to an infection or disease²⁰.

There is significant decrease (P=0.0005) in total antioxidant level of Smokers without any caries when compared to nonsmokers without any dental caries. This finding was also reported in few previous studies^7,16.

The Total antioxidant level in smokers with St.mutans caries (Group 1) decreased significantly (P<0.001) than in nonsmokers with St.mutans caries (Group 4). Cigarette smoking was shown to be associated with the prevalence of caries²¹ and free radicals in cigarette smoke^22,23 deplete the antioxidant level.

Conclusion

In this noninvasive study we considered the patients with St.mutans caries and smoking habit. We have found that the Total antioxidant level does not decrease in individuals with St.mutans caries without any smoking habit, but it decreases in individuals with smoking habit. So it may be suggesting that smoking may increase the prevalence of dental caries or it may worsen the conditions in dental caries as the free radical produced by the smoke reported to deplete the total antioxidant level.